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Sample records for blue led solution

  1. 'No blue' LED solution for photolithography room illumination

    DEFF Research Database (Denmark)

    Ou, Haiyan; Corell, Dennis Dan; Dam-Hansen, Carsten;

    2010-01-01

    This paper explored the feasibility of using a LED-based bulb as the illumination light source for photolithography room. A no-blue LED was designed, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that......, colorimetric values were calculated and compared on terms of chromatic coordinates, correlated color temperature, color rendering index, and chromatic deviation. Gretagmacbeth color charts were used as a more visional way to compare the two light sources, which shows that our no-blue LED bulb has much better...... color rendering ability than the YFT. Furthermore, LED solution has design flexibility to improve it further. The prototype has been tested with photoresist SU8-2005. Even after 15 days of illumination, no effect was observed. So this LED-based solution was demonstrated to be a very promising light...

  2. Nobel Prize for blue LEDs

    Science.gov (United States)

    Kraftmakher, Yaakov

    2015-05-01

    A brief review of lighting technologies is presented. Unavoidable restrictions for incandescent light bulbs caused by the Planck distribution and properties of the human eye are illustrated. The efficiency and luminous efficacy of thermal radiation are calculated for various temperatures; the results clearly show the limitations for thermal radiators. The only way to overcome these limitations is using non-thermal radiators, such as fluorescent lamps and light-emitting diodes (LEDs). Unique advantages of LEDs undoubtedly made a revolution in this field. A crucial element of this progress is the blue LEDs (Nobel Prize 2014). Some experiments with a blue and a green LED are described: (i) the luminescence triggered in a green-yellow phosphor inside a white LED by the blue LED; (ii) radiant spectra and ‘efficiency droop’ in the LEDs; (iii) modulation of the blue LED up to 4 MHz; and (iv) the h/e ratio from the turn-on voltage of the green LED. The experiments are suitable for undergraduate laboratories and usable as classroom demonstrations.

  3. Modeling of spectral characteristics of blue LEDs

    DEFF Research Database (Denmark)

    Thorseth, Anders

    2010-01-01

    We have investigated three models currently used for the spectral power distributions of single color LEDs. We present empirical models using a single and a double Gaussian distribution, and a model using principles from solid state physics, further more we show how the model parameters are...... expected to vary with current and junction temperature. Commercial high power blue LEDs were measured with respect to spectral distribution and chromaticity and the result was compared with the model predictions. We have found that the models predict significantly different results with respect to...... chromaticity and other color characteristics. The model that fits measurements best has chromaticity within a 5-step MacAdam ellipsis, and the worst preforming model a 12-step MacAdam ellipsis away from the measured chromaticity. We also show a method to infer internal characteristics of the the LED using the...

  4. Blue laser diode (LD) and light emitting diode (LED) applications

    Science.gov (United States)

    Bergh, Arpad A.

    2004-09-01

    The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography.As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc.Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity.Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care.

  5. Blue laser diode (LD) and light emitting diode (LED) applications

    International Nuclear Information System (INIS)

    The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography. As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc. Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity. Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Nobel Prize in Physics: The birth of the blue LED

    Science.gov (United States)

    Nanishi, Yasushi

    2014-12-01

    The development of practical blue LEDs required great perseverance by several Japanese scientists who had to learn how to fabricate high-quality films of GaN and effectively dope them to create light-emitting p-n junctions.

  7. Compact collimators for high brightness blue LEDs using dielectric multilayers

    NARCIS (Netherlands)

    Cornelissen, H.J.; Ma, H.; Ho, C.; Li, M.; Mu, C.

    2011-01-01

    A novel method is presented to inject the light of millimeter-sized high-brightness blue LEDs into light guides of submillimeter thickness. Use is made of an interference filter that is designed to pass only those modes that will propagate in the light guide by total internal reflection. Other modes

  8. Underwater Wireless Optical Communication System Using Blue LEDs

    Science.gov (United States)

    Lin, Aobo; Tong, Zheng; Song, Yuhang; Kong, Meiwei; Xu, Jing

    2016-02-01

    We demonstrate a self-designed underwater wireless optical communication system using blue LEDs. The performance of the transmitter and receiver was experimentally investigated. Four different square wave signals (10 KHz, 100 KHz, 500 KHz and 1 MHz) were successfully transmitted via a short water channel at the first phase.

  9. A stabilised blue-violet LED for VPT photocathode evaluation

    CERN Document Server

    Hobson, Peter R

    2000-01-01

    A highly stable blue-violet light source ( peak wavelength 430 nm) based on the IPL 10630PAL self-monitoring LED is described. A thermoelectric cooler has been used to stabilise the 10630PAL device and the external LED current-control electronics to +- 0.1% K. The light intensity was measured to be stable to +- 0.03% for five hours, the repeatability was +- 0.1% The output spectrum of the LED is a good match to the scintillation emission of PbWO4, and this source will be used to evaluate the spatial and angular uniformity of VPT photocathodes for the endcap calorimeter.

  10. New High Efficiency LED Lighting Solution

    Institute of Scientific and Technical Information of China (English)

    DING Ke; NIU Ping-juan; FU Xian-song

    2008-01-01

    As the quality of power LED improves and the cost of power LED reduces, semiconductor lighting will replace incandescent and fluorescent lighting gradually, causing another revolution on the lighting history. And its driving solution has been greatly accelerated. Based on the white power LED I-V characteristics and the application ambiance, proposed is a new LED lighting solution, suiting indoor and outdoor illumination. According to the test results, the design is optimized, and the electrical efficiency is 95% and the output current deviation is 13.0%.

  11. Different degradation behaviors of InGaN/GaN MQWs blue and violet LEDs

    International Nuclear Information System (INIS)

    InGaN/GaN multiple quantum wells (MQWs) blue and violet light-emitting diodes (LEDs) were stressed under the injection current density of 26.5 A/cm2 for about 400 h at room temperature. Degradation behaviors of blue and violet LEDs were compared. Two stages of degradation were identified in the blue and violet LEDs. At the initial stage, the violet LEDs degraded very fast, but the blue LEDs degraded relatively slow. At later stage, both blue and violet LEDs showed similar degradation rates. Analyses of the L-I and I-V characteristics revealed that the increase of effective nonradiative recombination centers in the active regions was responsible for both blue and violet LED degradations. Rapid degradation of violet LEDs at early stage resulted from dramatical increase of the effective nonradiative centers. More indium in the MQWs might be helpful for better reliability performance of blue LEDs.

  12. Spectral optimization of the color temperature tunable white light-emitting diode (LED) cluster consisting of direct-emission blue and red LEDs and a diphosphor conversion LED.

    Science.gov (United States)

    Zhong, Ping; He, Guoxing; Zhang, Minhao

    2012-09-10

    The correlated color temperature (CCT) tunable white-light LED cluster, which consists of direct-emission blue and red LEDs as well as phosphor-conversion (PC) LEDs packaged by combining green and orange phosphors with a blue LED die, has been obtained by nonlinear program for maximizing luminous efficacy (LE) of radiation (LER) under conditions of both color rendering index (CRI) and special CRI of R9 for strong red above 90 at CCTs of 2700 K to 6500 K. The optimal peak wavelengths of blue LED, red LED, blue LED die, green and orange phosphors are 465 nm, 628 nm, 452 nm, 530 nm and 586 nm, respectively. The real CCT tunable PC/red/blue LED cluster with CRIs of 90~96, R9s of 90~96, CQSs of 89~94, LERs of 303~358 lm/W, and LEs of 105~119 lm/W has been realized at CCTs of 2722 K to 6464 K. The deviation of the peak wavelength should be less than ± 5 nm for blue LED die, ± 1 nm for red LED, and ± 2 nm for blue LED to achieve the PC/R/B LED cluster with high optical performance. PMID:23037535

  13. Evaluation of cotton-fabric bleaching using hydrogen peroxide and Blue LED

    Science.gov (United States)

    de Oliveira, Bruno P.; Moriyama, Lilian T.; Bagnato, Vanderlei S.

    2015-06-01

    The raw cotton production requires multiple steps being one of them the removal of impurities acquired during previous processes. This procedure is widely used by textile industries around the world and is called bleaching. The raw cotton is composed by cellulosic and non-cellulosic materials like waxes, pectins and oils, which are responsible for its characteristic yellowish color. The bleaching process aims to remove the non-cellulosic materials concentration in the fabric, increasing its whiteness degree. The most used bleaching method utilizes a bath in an alkali solution of hydrogen peroxide, stabilizers and buffer solutions under high temperature. In the present study we evaluated the possibility of using a blue illumination for the bleaching process. We used blue LEDs (450 nm) to illuminate an acid hydrogen peroxide solution at room temperature. The samples treated by this method were compared with the conventional bleaching process through a colorimetric analysis and by a multiple comparison visual inspection by volunteers. The samples were also studied by a tensile test in order to verify the integrity of the cloth after bleaching. The results of fabric visual inspection and colorimetric analysis showed a small advantage for the sample treated by the standard method. The tensile test showed an increasing on the yield strength of the cloth after blue light bleaching. The presented method has great applicability potential due to the similar results compared to the standard method, with relative low cost and reduced production of chemical waste.

  14. Data in support of effect of blue LED irradiation in human lymphoma cells

    Directory of Open Access Journals (Sweden)

    Phil-Sun Oh

    2016-03-01

    Full Text Available As a new and preferred light source for phototherapy, blue light emitting diodes (LEDs with wavelengths of 400–500 nm have been used to treat hyperbilirubinaemia in infantile jaundice [1]. Recent studies report that blue LED irradiation induces apoptosis by stimulating a mitochondrial pathway and reduces the early growth rate of melanoma cells in mice [2]. Here, we detected the induction of apoptotic cell death and formation of autophagosome in human B lymphoma cells after irradiation with blue LED. This paper provides data in support of the research article entitled “Blue light emitting diode induces apoptosis in lymphoid cells by stimulating autophagy” [3].

  15. Data in support of effect of blue LED irradiation in human lymphoma cells.

    Science.gov (United States)

    Oh, Phil-Sun; Hwang, Hyosook; Jeong, Hwan-Seok; Kwon, Jeongil; Kim, Hyun-Soo; Kim, Minjoo; Lim, SeokTae; Sohn, Myung-Hee; Jeong, Hwan-Jeong

    2016-03-01

    As a new and preferred light source for phototherapy, blue light emitting diodes (LEDs) with wavelengths of 400-500 nm have been used to treat hyperbilirubinaemia in infantile jaundice [1]. Recent studies report that blue LED irradiation induces apoptosis by stimulating a mitochondrial pathway and reduces the early growth rate of melanoma cells in mice [2]. Here, we detected the induction of apoptotic cell death and formation of autophagosome in human B lymphoma cells after irradiation with blue LED. This paper provides data in support of the research article entitled "Blue light emitting diode induces apoptosis in lymphoid cells by stimulating autophagy" [3]. PMID:26909378

  16. HB LED color mixture traffic light solution based on EZ-color

    Science.gov (United States)

    Hong, Qunhuan; Wang, Weijian; Xiao, Zhihong

    2010-02-01

    This paper introduces a traffic light design solution using HB LED color mixture,namely an implementation method using a set of traffic lights composed of red, green and blue HB LED to replace ordinary red, yellow and green lights. This scheme realizes HB LED color mixture lighting design on the basis of Cypress EZ-Color controller and codeless embedded design software PSoC Express.

  17. Data in support of effect of blue LED irradiation in human lymphoma cells

    OpenAIRE

    Phil-Sun Oh; Hyosook Hwang; Hwan-Seok Jeong; Jeongil Kwon; Hyun-Soo Kim; Minjoo Kim; SeokTae Lim; Myung-Hee Sohn; Hwan-Jeong Jeong

    2016-01-01

    As a new and preferred light source for phototherapy, blue light emitting diodes (LEDs) with wavelengths of 400–500 nm have been used to treat hyperbilirubinaemia in infantile jaundice [1]. Recent studies report that blue LED irradiation induces apoptosis by stimulating a mitochondrial pathway and reduces the early growth rate of melanoma cells in mice [2]. Here, we detected the induction of apoptotic cell death and formation of autophagosome in human B lymphoma cells after irradiation with b...

  18. Regulation of ascorbic acid metabolism by blue LED light irradiation in citrus juice sacs.

    Science.gov (United States)

    Zhang, Lancui; Ma, Gang; Yamawaki, Kazuki; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Ohta, Satoshi; Kato, Masaya

    2015-04-01

    In the present study, the effects of red and blue LED lights on the accumulation of ascorbic acid (AsA) were investigated in the juice sacs of three citrus varieties, Satsuma mandarin, Valencia orange, and Lisbon lemon. The results showed that the blue LED light treatment effectively increased the AsA content in the juice sacs of the three citrus varieties, whereas the red LED light treatment did not. By increasing the blue LED light intensity, the juice sacs of the three citrus varieties accumulated more AsA. Moreover, continuous irradiation with blue LED light was more effective than pulsed irradiation for increasing the AsA content in the juice sacs of the three citrus varieties. Gene expression results showed that the modulation of AsA accumulation by blue LED light was highly regulated at the transcription level. The up-regulation of AsA biosynthetic genes (CitVTC1, CitVTC2, CitVTC4, and CitGLDH), AsA regeneration genes (CitMDAR1, CitMDAR2, and CitDHAR) and two GSH-producing genes (CitGR and CitchGR) contributed to these increases in the AsA content in the three citrus varieties. PMID:25711821

  19. Visible light communication using a blue GaN mu LED and fluorescent polymer color converter

    OpenAIRE

    Chun, Hyunchae; Manousiadis, Pavlos; Rajbhandari, Sujan; Vithanage, D.A.; Faulkner, G.; Tsonev, Dobroslav; Mckendry, Jonathan J.D.; Videv, Stefan; Xie, Enyuan; Gu, Erdan; Martin D. Dawson; Haas, Harald; Turnbull, Graham; Samuel, Ifor D. W.; O'Brien, Dominic

    2014-01-01

    This letter presents a novel technique to achieve high-speed visible light communication (VLC) using white light generated by a blue GaN mu LED and a yellow fluorescent copolymer. We generated white light suitable for room illumination by optimizing the ratio between the blue electroluminescence of the mu LED and yellow photoluminescence of the copolymer color converter. Taking advantage of the components' high bandwidth, we demonstrated 1.68 Gb/s at a distance of 3 cm (at 240 lx illumination...

  20. Application of blue-green and ultraviolet micro-LEDs to biological imaging and detection

    International Nuclear Information System (INIS)

    This paper reviews authors' laboratory's work on the development of nitride-based blue-green and ultraviolet microscale LED devices with particular classes of imaging and spectroscopic applications in cellular level biology. Starting from neuroscience, we illustrate the utility of blue-green micro-LEDs for voltage-sensitive dye imaging of individual neural cells, as well as their ultraviolet counterparts for photostimulation of neurons. Arrays of micro-LEDs are also shown to be useful in projecting spatiotemporal patterns of photoexcitation to study the visual system development in living animals. As another illustration of the utility of the emerging nitride microdevice technology, we demonstrate the application of UV micro-LED arrays in bio-sensing technology as the core of a real-time fluorescence spectroscopy biowarning system. (invited paper)

  1. Effect of blue LED light intensity on carotenoid accumulation in citrus juice sacs.

    Science.gov (United States)

    Zhang, Lancui; Ma, Gang; Yamawaki, Kazuki; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Ohta, Satoshi; Kato, Masaya

    2015-09-01

    In the present study, the effects of blue LED light intensity on carotenoid accumulation and expression of genes related to carotenoid biosynthesis were investigated in the juice sacs of Satsuma mandarin (Citrus unshiu Marc.) and Valencia orange (Citrus sinensis Osbeck) in vitro. The results showed that 100 μmol m(-2)s(-1) blue LED light (100B) was effective for increasing carotenoid content, especially β-cryptoxanthin, in Satsuma mandarin after cultured in vitro for four weeks. In Valencia orange, in contrast, 50 μmol m(-2)s(-1) blue LED light (50B) treatment was effective for inducing carotenoid accumulation through increasing the contents of two major carotenoids, all-trans-violaxanthin and 9-cis-violaxanthin. In addition, gene expression results showed that the simultaneous increases in the expression of genes (CitPSY, CitPDS, CitZDS, CitLCYb2, and CitHYb) involved in producing β,β-xanthophylls were well consistent with the accumulation of β-cryptoxanthin in Satsuma mandarin under 100B, and violaxanthin in Valencia orange under 50B. The results presented herein contribute to further elucidating the regulatory mechanism of carotenoid accumulation by blue LED light. PMID:26432407

  2. Effect of phototherapy with turquoise vs. blue LED light of equal irradiance in jaundiced neonates

    DEFF Research Database (Denmark)

    Ebbesen, Finn; Vandborg, Pernille K; Madsen, Poul H;

    2016-01-01

    phototherapy is light emitting diodes (LEDs). AIM: Compare the bilirubin reducing effect in jaundiced neonates treated either with turquoise- or blue LED light with peak emission at 497 nm or 459 nm, respectively, with equal irradiance on the infants. METHODS: Infants with gestational age ≥33 weeks and...... uncomplicated hyperbilirubinemia were randomized to either turquoise- or blue LED light from above, and were treated for 24 h. The mean irradiance footprint at skin level was 5.2x10(15) and 5.1x10(15) photons /cm(2)/s, respectively. RESULTS: 46 infants received turquoise- and 45 blue light. The median (95% CI......) decrease of total serum bilirubin was 35.3% (32.5; 37.3) and 33.1% (27.1; 36.8) for infants treated with turquoise- and blue light, respectively. The difference was non-significant (p=0.53). The decrease was positively correlated to postnatal age and negatively to birth weight. CONCLUSION: Using LED light...

  3. Comparative Study of Lettuce and Radish Grown Under Red and Blue LEDs and White Fluorescent Lamps

    Science.gov (United States)

    Mickens, Matthew A.; Massa, Gioia; Newsham, Gerard; Wheeler, Raymond; Birmele, Michele

    2016-01-01

    Growing vegetable crops in space will be an essential part of sustaining astronauts during long-range missions. To drive photosynthesis, red and blue light-emitting diodes (LEDs) have attracted attention because of their efficiency, longevity, small size, and safety. In efforts to optimize crop yield, there is also recent interest in analyzing the subtle effects of additional wavelengths on plant growth. For instance, since plants often look purplish gray under red and blue LEDs, the addition of green light allows easy recognition of disease and the assessment of plant health status. However, it is important to know if wavelengths outside the traditional red and blue wavebands have a direct effect on enhancing or hindering the mechanisms involved in plant growth. In this experiment, a comparative study was performed on two short cycle crops of red romaine lettuce (Lactuca sativa cv. "Outredgeous") and radish (Raphanus sativa cv. 'Cherry Bomb'), which were grown under two light treatments. The first treatment being red (630 nm) and blue (450 nm) LEDs alone, while the second treatment consisted of daylight tri-phosphor fluorescent lamps (CCT approximately 5000 K) at equal photosynthetic photon flux (PPF). The treatment effects were evaluated by measuring the fresh biomass produced, plant morphology and leaf dimensions, leaf chlorophyll content, and adenosine triphosphate (ATP) within plant leaf/storage root tissues.

  4. Violet-blue LEDs based on p-GaN/n-ZnO nanorods and their stability

    International Nuclear Information System (INIS)

    In this paper, we report a fabrication, characterization and stability study of p-GaN/n-ZnO nanorod heterojunction light-emitting devices (LEDs). The LEDs were assembled from arrays of n-ZnO vertical nanorods epitaxially grown on p-GaN. LEDs showed bright electroluminescence in blue (440 nm), although weaker violet (372 nm) and green-yellow (550 nm) spectral components were also observed. The device characteristics are generally stable and reproducible. The LEDs have a low turn-on voltage (∼5 V). The electroluminescence (EL) is intense enough to be noticed by the naked eye, at an injection current as low as ∼ 40 μA (2.1 x 10-2 A cm-2 at 7 V bias). Analysis of the materials, electrical and EL investigations point to the role of a high quality of p-n nano-heterojunction which facilitates a large rectification ratio (320) and a stable reverse current of 2.8 μA (1.4 x 10-3 A cm-2 at 5 V). Stability of EL characteristics was investigated in detail. EL intensity showed systematic degradation over a short duration when the LED was bias-stressed at 30 V. At smaller bias (<20 V) LEDs tend to show a stable and repeatable EL characteristic. Thus a simple low temperature solution growth method was successfully exploited to realize nanorod/film heterojunction LED devices with predictable characteristics.

  5. Supplemental Blue LED Lighting Array to Improve the Signal Quality in Hyperspectral Imaging of Plants

    Directory of Open Access Journals (Sweden)

    Anne-Katrin Mahlein

    2015-06-01

    Full Text Available Hyperspectral imaging systems used in plant science or agriculture often have suboptimal signal-to-noise ratio in the blue region (400–500 nm of the electromagnetic spectrum. Typically there are two principal reasons for this effect, the low sensitivity of the imaging sensor and the low amount of light available from the illuminating source. In plant science, the blue region contains relevant information about the physiology and the health status of a plant. We report on the improvement in sensitivity of a hyperspectral imaging system in the blue region of the spectrum by using supplemental illumination provided by an array of high brightness light emitting diodes (LEDs with an emission peak at 470 nm.

  6. Study on Healing Environment Using Green, Blue and Red LED and Aroma

    Science.gov (United States)

    Miyaho, Noriharu; Konno, Noriko; Shimada, Takamasa

    In this paper we evaluated the effects of 1/f fluctuation of Green LED light emitted from the specific object by using psychological and physiological experimental tests of spectral electroencephalogram (EEG) topography. In addition, we also verified that the combination of appropriate aroma, blue LED light irradiation and music such as “Mozart: Serenade in Eine Kleine Nacht Musik” has improved mental healing conditions. We confirmed the possibility that the effect of “Healing” would be improved by the above mentioned environments.

  7. High performance of vegetables, flowers, and medicinal plants in a red-blue LED incubator for indoor plant production

    OpenAIRE

    Sabzalian, Mohammad; Heydarizadeh, Parisa; Zahedi, Morteza; Boroomand, Amin; Agharokh, Mehran; Sahba, Mohammad; Schoefs, Benoît

    2014-01-01

    International audience In urban agriculture, plant growth is limited by the availability of light. Light emitting diodes (LED) could provide specific quality and quantity of light overcoming existing limitations for normal plant growth. However, there have been very few investigations on the applications of LED in incubators and plant growth chambers. The devices fabricated in this study, were lighted with 100 % red, 100 % blue, 70 % red plus 30 % blue, or 100 % white LED. We cultivated Me...

  8. Photodynamic inactivation of Escherichia coli by methylene blue and malachite green under red LED light

    Directory of Open Access Journals (Sweden)

    Guilherme K. F. Hasegawa

    2015-04-01

    Full Text Available This study assessed the effectiveness of methylene blue (MB and malachite green (MG on photodynamic inactivation (PDI of Escherichia coli. The photosensitizers methylene blue (1000 mol L-1 and malachite green (250 mol L-1 were activated with a red light-emitting diode (LED lamp (max = 636 nm. Bacterial suspensions containing 106 CFU mL-1 were irradiated for 5, 10 and 15 minutes (energy density = 119.9 J cm-2, 223.9 J cm-2 and 335.8 J cm-2, respectively. The following experimental conditions were performed for each photosensitizer: no light irradiation or photosensitizer, irradiation only, photosensitizer only or irradiation in the presence of a photosensitizer. Next, serial dilutions were prepared and seeded onto PCA medium for the determination of the number of colony-forming units per milliliter (CFU mL-1. The results were subjected to analysis of variance (ANOVA and Tukey test (P<0.05. Photodynamic inactivation using MB and MG was effective in reducing the number of E. coli. Malachite green (250 µmol L-1 photosensitization was able to achieve reductions of over 89% in the viable counts after 15 min of irradiation and methylene blue (1000 µmol L-1, at the same conditions of irradiation, showed a rate growth inhibition of 94.6%. The red LED light used has proven to be effective in the photosensitizing dyes and proved a good alternative to conventional light sources such as laser.

  9. The value, solutions, and costs of patterning LED's

    Science.gov (United States)

    Watts, Michael P. C.; Zoorob, M.; Lee, T.; McKenzie, J.

    2007-02-01

    The literature on high brightness LED's shows that patterning the top surface of LED's with photonic crystals is being used to create the most intense LED light sources. The best example is that you can now buy projection displays that are illuminated by LED's with Photonic Crystals. The experimental and model data, reviewed in this article, shows that patterning delivers value through improved beam shaping and light extraction using carefully optimized photonic crystals. The data also suggests that in the future, patterning in combination with sub micron device layers and strategically placed mirrors can produce extraction efficiencies of greater than 80%. In addition, patterning can improve current spreading and reduce epitaxy defects. The long term goal is to develop a LED that can be used with minimal additional packaging to focus the light or extract heat. The solution to low cost patterning for Photonic Crystals 100 nm features is to use imprint. The imprint patterning process is implemented in a module that consists of a clean and coat tool, an imprint tool and an etch tool. Cleaning is essential because imprint is a contact technology and particles will lead to process defects and mold damage. There are 2 companies that are developing production tools for LED applications; Molecular Imprints (MII) and Obducat. There are 2 companies that are supporting research tools, and expect to develop production systems in response to customer order, EV Group and Nanonex. The principal difference between imprint suppliers are the different strategies used to conform the mold to the substrate, and the state of system development. To date MII has published the most complete process performance data on an automated production tool. The cost of patterning is less than 0.5 cent per device. First the value of increased LED output will be described, followed by a discussion of the different patterning solutions for improving output, then the different solutions for creating

  10. Metabolic activity of odontoblast-like cells irradiated with blue LED (455 nm).

    Science.gov (United States)

    de Almeida, Leopoldina Fátima Dantas; Basso, Fernanda Gonçalves; Turrioni, Ana Paula Silveira; de-Souza-Costa, Carlos Alberto; Hebling, Josimeri

    2016-01-01

    Blue light emitting diodes (LEDs) are frequently used in dentistry for light activation of resin-based materials; however, their photobiostimulatory effects have not yet been fully investigated. This study aimed to investigate the effect of blue LED (455 nm) on the metabolism of odontoblast-like cells MDPC-23. Energy doses of 2 and 4 J/cm(2) were used at 20 mW/cm(2) fixed power density. MDPC-23 cells were seeded at 10,000 cells/cm(2) density in Dulbecco's modified Eagle's medium (DMEM) containing 10 % fetal bovine serum (FBS). After 12 h, the culture medium was replaced with new DMEM supplemented with 0.5 % of FBS, and the cells were incubated for further 12 h. After that, single irradiation was performed to the culture, under selected parameters. Cell viability evaluations (Alamar Blue Assay, n = 12), number of viable cells (Trypan Blue Assay, n = 12), morphological analysis by scanning electron microscopy (SEM, n = 2), gene expression (n = 6) of alkaline phosphatase (Alp), collagen (Col-1a1), and dental matrix protein (Dmp-1) (quantitative polymerase chain reaction (qPCR)) were performed 72 h after irradiation. Data were analyzed by Kruskal-Wallis, ANOVA, and Tukey tests (p < 0.05). Direct light application at 4 J/cm(2) energy dose had no negative effects on cell viability, while irradiation with 2 J/cm(2) reduced cell metabolism. None of doses affected the number of viable cells compared with the control group. The two energy doses downregulated the expression of Alp; however, expression of Col-1a1 and Dmp-1 had no alteration. Cells presented change in the cytoskeleton only when irradiated with 2 J/cm(2). In conclusion, the blue LED (455 nm) irradiation, under the evaluated parameters, had no biostimulatory effects on MDPC-23 cells. PMID:26608964

  11. Development of OSL system using two high-density blue LEDs equipped with liquid light guides

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.H. [Division of Earth and Environmental Sciences, Korea Basic Science Institute, Chungbuk 363-883 (Korea, Republic of); Kim, M.J. [Center for Applied Radiation Research, Neosiskorea Co., Ltd., Daejeon 305-380 (Korea, Republic of); Cheong, C.S. [Division of Earth and Environmental Sciences, Korea Basic Science Institute, Chungbuk 363-883 (Korea, Republic of); Hong, D.G., E-mail: dghong@kangwon.ac.kr [Department of Physics, Kangwon National University, Chunchon 200-701 (Korea, Republic of)

    2014-03-15

    In recent years, considerable developments in optically stimulated luminescence (OSL) have been made in the fields of radiation dosimetry, age determination, and medical applications. A compact and economical OSL system comprising a precision x-y-z stage for loading 12 samples, a small X-ray generator for radiation dosing, and two powerful blue light emitting diodes (LEDs) for optical stimulation equipped with VIS liquid light guides (VIS-LLGs) has been developed. This paper describes the principal features of the system along with the examples of measurements performed by the system.

  12. OSL response bleaching of BeO samples, using fluorescent light and blue LEDs

    Science.gov (United States)

    Groppo, D. P.; Caldas, L. V. E.

    2016-07-01

    The optically stimulated luminescence (OSL) is widely used as a dosimetric technique for many applications. In this work, the OSL response bleaching of BeO samples was studied. The samples were irradiated using a beta radiation source (90Sr+90Y); the bleaching treatments (fluorescent light and blue LEDs) were performed, and the results were compared. Various optical treatment time intervals were tested until reaching the complete bleaching of the OSL response. The best combination of the time interval and bleaching type was analyzed.

  13. Compound parabolic concentrator design for red, green, blue, and white LED light mixing

    Science.gov (United States)

    Wei, An-Chi; Lo, Shih-Chieh; Hung, Pei-Fang; Lee, Ju-Yi; Yeh, Hong-Yih; Huang, Hong-Cheng; Li, Chia-Ming

    2016-08-01

    A light-mixing module consisting of a compound parabolic concentrator (CPC) and a fiber for mixing light from red, green, blue, and white (RGBW) LEDs was proposed. The design principle was investigated and a design prototype was demonstrated in a simulation. The simulated results showed that the chromatic nonuniformity was reduced to 1/10 when the fiber length was 40 times the core width, and the module efficiencies were more than 80% and more than 60% when the fiber lengths were 350 mm and 5 m, respectively. The proposed module is suitable for solar lighting compensation or indoor lighting, such as plant-factory lighting.

  14. Effect of LED Blue Light on Penicillium digitatum and Penicillium italicum Strains.

    Science.gov (United States)

    Lafuente, María T; Alférez, Fernando

    2015-11-01

    Studies on the antimicrobial properties of light have considerably increased due in part to the development of resistance to actual control methods. This study investigates the potential of light-emitting diodes (LED) blue light for controlling Penicillium digitatum and Penicillium italicum. These fungi are the most devastating postharvest pathogens of citrus fruit and cause important losses due to contaminations and the development of resistant strains against fungicides. The effect of different periods and quantum fluxes, delaying light application on the growth and morphology of P. digitatum strains resistant and sensitive to fungicides, and P. italicum cultured at 20°C was examined. Results showed that blue light controls the growth of all strains and that its efficacy increases with the quantum flux. Spore germination was always avoided by exposing the cultures to high quantum flux (700 μmol m(-2) s(-1) ) for 18 h. Continuous light had an important impact on the fungus morphology and a fungicidal effect when applied at a lower quantum flux (120 μmol m(-2) s(-1) ) to a growing fungus. Sensitivity to light increased with mycelium age. Results show that blue light may be a tool for P. digitatum and P. italicum infection prevention during handling of citrus fruits. PMID:26288067

  15. A silicon wafer packaging solution for HB-LEDs

    Science.gov (United States)

    Murphy, Tom; Weichel, Steen; Isaacs, Steven; Kuhmann, Jochen

    2007-09-01

    In this paper we present HyLED, a silicon wafer packaging solution for high-brightness LEDs. The associated technology is batch micro-machining/metallisation processing of silicon wafers allowing significant reduction of the final device size. The presented package is multi-functional where the micro-machined cavity acts as reflector, thermal conductor and reservoir for the silicone/colour conversion substance. The base material, silicon, has excellent mechanical and thermal properties and enables direct integration of intelligence. We present customer specific solutions, open tool samples and performance data for optical and thermal parameters and reliability testing. Thermal resistance values of R<5 K/W, junction-to-board are demonstrated.

  16. 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

    Science.gov (United States)

    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.

  17. Photodynamic antimicrobial chemotherapy (PACT) against oral microorganisms with the use of blue LED associated to curcumin

    Science.gov (United States)

    Sampaio, Fernando José P.; Pires-Santos, Gustavo M.; de Oliveira, Susana C. P. S.; Monteiro, Juliana S. C.; Bagnato, Vanderlei S.; Pinheiro, Antônio L. B.

    2016-03-01

    The use of curcumin as antimicrobial agent has been suggested and this effect may be potentialized by appropriate light. This study evaluated the effect of PACT using blue LED (λ450ηm +/- 5ηm, 220mW and spot of 0.785 cm2) associated to Curcumin at different concentrations (75, 37.5, 18.75, 9.37 and 4.68 μg /mL). Microorganisms from the oral mucosa and the posterior region of the tongue were collected and inoculated into test tubes containing 8mL of TSB medium. For these assays were performed 16 readings. In the assays were used culture plate of 24 wells. To each well was added 400 μL of the suspension containing the microorganisms. Suspensions without curcumin were placed in eight wells. Elsewhere, curcumin was applied varying concentrations with pre-irradiation time of 5 min. After stirring, 200 μL aliquot was taken from each well and the readings were immediately carried out by a spectrophotometer (SPECTRA MAX). Assessments of turbidity were performed following CLSI standard methods. After 1 hour of incubation in a bacteriological oven, 200 μL aliquot was removed from the remaining wells for a second reading. The results showed a decrease of total microorganisms in the most of test groups. The best result of the PACT was with 75 μg/mL, showing 81% of inhibition. It is concluded that PACT with blue LED associated to Curcumin could be a potential mechanism for controlling microorganism proliferation on the oral cavity.

  18. Improving spinach, radish, and lettuce growth under red light-emitting diodes (LEDs) with blue light supplementation

    Science.gov (United States)

    Yorio, N. C.; Goins, G. D.; Kagie, H. R.; Wheeler, R. M.; Sager, J. C.

    2001-01-01

    Radish (Raphanus sativus L. cv. Cherriette), lettuce (Lactuca sativa L. cv. Waldmann's Green), and spinach (Spinacea oleracea L. cv. Nordic IV) plants were grown under 660-nm red light-emitting diodes (LEDs) and were compared at equal photosynthetic photon flux (PPF) with either plants grown under cool-white fluorescent lamps (CWF) or red LEDs supplemented with 10% (30 micromoles m-2 s-1) blue light (400-500 nm) from blue fluorescent (BF) lamps. At 21 days after planting (DAP), leaf photosynthetic rates and stomatal conductance were greater for plants grown under CWF light than for those grown under red LEDs, with or without supplemental blue light. At harvest (21 DAP), total dry-weight accumulation was significantly lower for all species tested when grown under red LEDs alone than when grown under CWF light or red LEDs + 10% BF light. Moreover, total dry weight for radish and spinach was significantly lower under red LEDs + 10% BF than under CWF light, suggesting that addition of blue light to the red LEDs was still insufficient for achieving maximal growth for these crops.

  19. Enhanced brightness from all solution processable biopolymer LED

    Science.gov (United States)

    Pradeep, C.; Namboothiry, M. A. G.; Vallabhan, C. P. G.; Radhakrishnan, P.; Nampoori, V. P. N.

    2015-08-01

    Biopolymer light emitting diodes were fabricated by using all solution processable polymers incorporating biomaterials such as deoxyribonucleic acid lipid complex as an electron blocking layer. Light emission is from a blend of fluorene based copolymers. The devices with electron blocking layer exhibited higher brightness and luminous efficiency. The increased luminance of the multilayer polymer LED is attributed to the contribution from DNA:CTMA as electron blocking layer and PFN, a derivative of polyfluorene, as electron injection layer. Our results show four fold increase in luminance values when DNA is used as electron blocking layer.

  20. Design and fabrication of adjustable red-green-blue LED light arrays for plant research

    Directory of Open Access Journals (Sweden)

    Kenitz J Dustin

    2005-08-01

    Full Text Available Abstract Background Although specific light attributes, such as color and fluence rate, influence plant growth and development, researchers generally cannot control the fine spectral conditions of artificial plant-growth environments. Plant growth chambers are typically outfitted with fluorescent and/or incandescent fixtures that provide a general spectrum that is accommodating to the human eye and not necessarily supportive to plant development. Many studies over the last several decades, primarily in Arabidopsis thaliana, have clearly shown that variation in light quantity, quality and photoperiod can be manipulated to affect growth and control developmental transitions. Light emitting diodes (LEDs has been used for decades to test plant responses to narrow-bandwidth light. LEDs are particularly well suited for plant growth chambers, as they have an extraordinary life (about 100,000 hours, require little maintenance, and use negligible energy. These factors render LED-based light strategies particularly appropriate for space-biology as well as terrestrial applications. However, there is a need for a versatile and inexpensive LED array platform where individual wavebands can be specifically tuned to produce a series of light combinations consisting of various quantities and qualities of individual wavelengths. Two plans are presented in this report. Results In this technical report we describe the practical construction of tunable red-green-blue LED arrays to support research in plant growth and development. Two light fixture designs and corresponding circuitry are presented. The first is well suited for a laboratory environment for use in a finite area with small plants, such as Arabidopsis. The second is expandable and appropriate for growth chambers. The application of these arrays to early plant developmental studies has been validated with assays of hypocotyl growth inhibition/promotion and phototropic curvature in Arabidopsis seedlings

  1. OFDM-based broadband underwater wireless optical communication system using a compact blue LED

    Science.gov (United States)

    Xu, Jing; Kong, Meiwei; Lin, Aobo; Song, Yuhang; Yu, Xiangyu; Qu, Fengzhong; Han, Jun; Deng, Ning

    2016-06-01

    We propose and experimentally demonstrate an IM/DD-OFDM-based underwater wireless optical communication system. We investigate the dependence of its BER performance on the training symbol number as well as LED's bias voltage and driving voltage. With single compact blue LED and a low-cost PIN photodiode, we achieve net bit rates of 225.90 Mb/s at a BER of 1.54×10-3 using 16-QAM and 231.95 Mb/s at a BER of 3.28×10-3 using 32-QAM, respectively, over a 2-m air channel. Over a 2-m underwater channel, we achieve net bit rates of 161.36 Mb/s using 16-QAM, 156.31 Mb/s using 32-QAM, and 127.07 Mb/s using 64-QAM, respectively. The corresponding BERs are 2.5×10-3, 7.42×10-4, and 3.17×10-3, respectively, which are all below the FEC threshold.

  2. Tissue slides analysis using red, green, and blue LEDs as microscope light source

    Science.gov (United States)

    Pratavieira, Sebastião.; Navascues, Felipe F.; de Souza, Larissa M.; Rosa, Ramon G. T.; Kurachi, Cristina; Bagnato, Vanderlei S.

    2016-03-01

    The optical microscopy is one of the most powerful tool in the analysis of biological systems. The usual transmitted light microscope uses a white light lamp as source, what sometimes does not bring optimal results, making it necessary to introduce filters to change some illumination properties like the color temperature or the color itself. There is, of course, an intrinsic limitation on the use of filters that is the lack of an analogical control on the illumination properties and a practical limitation that depends on the number of available filters. To address this need, we developed an illumination system based on (Red, Green and Blue) RGB LEDs, were the microscope operator can control the intensity of each one independently and manually. This paper details the developed system and describes the methods used to compare quantitatively the images acquired while using the standard white light illumination and the images obtained with the developed system. To quantify the contrast, we calculated the relative population standard deviation for the intensities of each channel of the RGB image. This procedure allowed us to compare and understand the major advantages of the developed illumination system. All analysis methods have shown that a contrast enhancement can be obtained under the RGB LEDs light. The presented illumination allowed us to visualize the structures in different samples with a better contrast without the need of any additional optical filters.

  3. The adsorption of methylene blue on montmorillonite from acid solutions

    Czech Academy of Sciences Publication Activity Database

    Klika, Z.; Pustková, P.; Dudová, M.; Čapková, P.; Kliková, Ch.; Matys Grygar, Tomáš

    2011-01-01

    Roč. 46, č. 3 (2011), s. 461-471. ISSN 0009-8558 Institutional research plan: CEZ:AV0Z40320502 Keywords : montmorillonite * dissolution * acid solutions * methylene blue * adsorption Subject RIV: DD - Geochemistry Impact factor: 1.053, year: 2011

  4. Observation of an improved healing process in superficial skin wounds after irradiation with a blue-LED haemostatic device.

    Science.gov (United States)

    Cicchi, Riccardo; Rossi, Francesca; Alfieri, Domenico; Bacci, Stefano; Tatini, Francesca; De Siena, Gaetano; Paroli, Gaia; Pini, Roberto; Pavone, Francesco S

    2016-06-01

    The healing process of superficial skin wounds treated with a blue-LED haemostatic device is studied. Four mechanical abrasions are produced on the back of 10 Sprague Dawley rats: two are treated with the blue-LED device, while the other two are left to naturally recover. Visual observations, non-linear microscopic imaging, as well as histology and immunofluorescence analyses are performed 8 days after the treatment, demonstrating no adverse reactions neither thermal damages in both abraded areas and surrounding tissue. A faster healing process and a better-recovered skin morphology are observed: the treated wounds show a reduced inflammatory response and a higher collagen content. Blue LED induced photothermal effect on superficial abrasions. PMID:26756549

  5. Polarization-multiplexed 2×2 phosphor-LED wireless light communication without using analog equalization and optical blue filter

    Science.gov (United States)

    Yeh, C. H.; Chen, H. Y.; Liu, Y. L.; Chow, C. W.

    2015-01-01

    We propose and experimentally demonstrate a 380 (2×190) Mbps phosphor-light-emitting-diode (LED) based visible light communication (VLC) system by using 2×2 polarization-multiplexing design for in-building access applications. To the best of our knowledge, this is the first time of employing polarization-multiplexing to achieve a high VLC transmission capacity by using phosphor-based white-LED without optical blue filter. Besides, utilizing the optimum resistor-inductor-capacity (RLC) bias-tee design, it can not only perform the function of combining the direct-current (DC) and the electrical data signal, but also act as a simple LED-Tx circuit. No optical blue filter and complicated post-equalization are required at the Rx. Here, the orthogonal-frequency-division-multiplexing (OFDM) quadrature-amplitude-modulation (QAM) with bit-loading is employed to enhance the transmission data rate.

  6. Synthesis of dental matrix proteins and viability of odontoblast-like cells irradiated with blue LED.

    Science.gov (United States)

    Alonso, Juliana Rosa Luiz; Turrioni, Ana Paula Silveira; Basso, Fernanda Gonçalves; de Souza Costa, Carlos Alberto; Hebling, Josimeri

    2016-04-01

    To evaluate the effect of irradiation with light-emitting diode (LED; 455 nm) on the viability and synthesis of dentin matrix proteins by odontoblast-like cells, MDPC-23 cells were cultivated (10(4) cells/cm(2)) in 24-well culture plates. After 12 h incubation in Dulbecco's modified Eagle's medium (DMEM), the cells were submitted to nutritional restriction by means of reducing the concentration of fetal bovine serum (FBS) for an additional 12 h. Cells were irradiated one single time with one of the following energy densities (EDs): 0.5, 2, 4, 10, or 15 J/cm(2) and irradiance fixed at 20 mW/cm(2). Non-irradiated cells served as control. After 72 h, cells were evaluated with regard to viability (methylthiazol tetrazolium technique (MTT)), mineralization nodule (MN) formation, total protein (TP) production, alkaline phosphatase activity (ALP), and collagen synthesis (Sircol), n = 8. The data were submitted to Kruskal-Wallis and Mann-Whitney tests (p > 0.05). There was no statistical difference between the viability of cells irradiated or not (control), for all the EDs. However, an increase in TP was observed for all the EDs when compared with the control group. A reduced ALP activity was seen in all irradiated groups, except for the ED of 0.5 J/cm(2), which did not differ from the control. There was no difference between the irradiated groups and control regarding collagen synthesis, with the exception of the ED of 10 J/cm(2), which inhibited this cell function. Significant reduction in MN occurred only for the EDs of 0.5 and 2 J/cm(2). The single irradiation with blue LED (455 nm), irradiance of 20 mW/cm(2), and energy densities ranging from 0.5 to 15 J/cm(2) exerted no effective biostimulatory capacity on odontoblast-like cells. PMID:26873499

  7. Changes on degree of conversion of dual-cure luting light-cured with blue LED

    Science.gov (United States)

    Bandéca, M. C.; El-Mowafy, O.; Saade, E. G.; Rastelli, A. N. S.; Bagnato, V. S.; Porto-Neto, S. T.

    2009-05-01

    The indirect adhesive procedures constitute recently a substantial portion of contemporary esthetic restorative treatments. The resin cements have been used to bond tooth substrate and restorative materials. Due to recently introduction of the self-bonding resin luting cement based on a new monomer, filler and initiation technology has become important to study the degree of conversion of these new materials. In the present work the polymerization reaction and the filler content of dual-cured dental resin cements were studied by means of infra-red spectroscopy (FT-IR) and thermogravimetry (TG). Twenty specimens were made in a metallic mold (8 mm diameter × 1 mm thick) from each of 2 cements, Panavia® F2.0 (Kuraray) and RelyX™ Unicem Applicap (3M/ESPE). Each specimen was cured with blue LED with power density of 500 mW/cm2 for 30 s. Immediately after curing, 24 and 48 h, and 7 days DC was determined. For each time interval 5 specimens were pulverized, pressed with KBr and analyzed with FT-IR. The TG measurements were performed in Netzsch TG 209 under oxygen atmosphere and heating rate of 10°C/min from 25 to 700°C. A two-way ANOVA showed DC (%) mean values statistically significance differences between two cements ( p cements ( p > 0.05). The Relx-Y™ Unicem mean values were significantly higher than Panavia® F 2.0. The degree of conversion means values increasing with the storage time and the filler content showed similar for both resin cements.

  8. Methylene blue adsorption from aqueous solution by dehydrated peanut hull

    International Nuclear Information System (INIS)

    Dyes are colour organic compounds which can colorize the other substances. These substances usually presents in the effluent water of many industries, such as textiles, leather, paper, printing and cosmetics. To observe the potential feasibility of removing colour, peanut hull as an agricultural by-product was dehydrated with sulphuric acid (DPH) and used for adsorption of methylene blue (MB) from aqueous solution. The effects of various parameters such as initial methylene blue concentrations, temperatures and particle sizes were examined and optimal experimental conditions were determined. Adsorption data were well described by the Langmuir model, although they could be modelled by the Freundlich model as well. The adsorption process followed the pseudo-second order kinetic model. The mass transfer model as intraparticle diffusion was applied to the experimental data to examine the mechanisms of rate controlling step. It was found that at the higher initial MB concentration, intraparticle diffusion is becoming significant controlling step. The thermodynamic constants of the adsorption process were also evaluated by using the Langmuir constants related to the equilibrium of adsorption at different temperatures. The results in this study indicated that dehydrated peanut hull was a good adsorbent for removing methylene blue

  9. Comparative Study of Lettuce and Radish Grown Under Red and Blue Light-Emitting Diodes (LEDs) and White Fluorescent Lamps

    Science.gov (United States)

    Mickens, Matthew A.

    2012-01-01

    Growing vegetable crops in space will be an essential part of sustaining astronauts during long-term missions. To drive photosynthesis, red and blue light-emitting diodes (LEDs) have attracted attention because of their efficiency, longevity, small size, and safety. In efforts to optimize crop production, there have also been recent interests in analyzing the subtle effects of green light on plant growth, and to determine if it serves as a source of growth enhancement or suppression. A comparative study was performed on two short cycle crops of lettuce (Outredgeous) and radish (Cherry Bomb) grown under two light treatments. The first treatment being red and blue LEDs, and the second treatment consisting of white fluorescent lamps which contain a portion of green light. In addition to comparing biomass production, physiological characterizations were conducted on how the light treatments influence morphology, water use, chlorophyll content, and the production of A TP within plant tissues.

  10. The photocatalysis of Bi{sub 2}MoO{sub 6} under the irradiation of blue LED

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuanyuan; Wang, Wenzhong, E-mail: wzwang@mail.sic.ac.cn; Zhang, Ling; Sun, Songmei

    2013-10-15

    Graphical abstract: - Highlights: • ·OH trap and hole sink were involved to investigate the active radicals. • Holes play a more important role in the degradation of RhB. • The ·OH were related to the decomposition of phenol. • The ·O{sub 2}-played a leading role in the photodegradation of phenol. • Blue LED is competitive and promising alternative for the future application. - Abstract: Bi{sub 2}MoO{sub 6} has been reported as a promising photocatalyst in wastewater treatment. The active radicals generated over the Bi{sub 2}MoO{sub 6} during the photocatalytic process were thought to be hydroxyl radical (·OH) but have not been proved. Herein, Bi{sub 2}MoO{sub 6} with nanoplate like morphology was synthesized and its photocatalytic performances in the degradation of rhodamine B (RhB) and phenol as colored and colorless model pollutants respectively were evaluated under the irradiation of blue light emitting diode (LED). The tert-butyl alcohol (TBA) as a ·OH trap and ethylene diamine tetraacetic acid (EDTA) as a hole sink were involved to investigate the main active groups that are generated on Bi{sub 2}MoO{sub 6} and function during the photodegradation of RhB and phenol. In addition, it is a competitive and promising alternative plan to use blue LED as light source for the future practical application in environmental remediation.

  11. Blue LED phototherapy for treating acne%LED蓝光治疗痤疮研究

    Institute of Scientific and Technical Information of China (English)

    魏勋斌; 谭渊; 刘光大; 张占祥; 王成

    2008-01-01

    观察便携型发光二极管(light-emitting diade,LED)蓝光治疗仪对轻中度痤疮的治疗效果.采用便携型LED蓝光治疗仪治疗轻中度痤疮患者10例,每周2次,共4周,用照相方法统计炎性痤疮个数,并分析炎性痤疮数目变化情况.结果表明,使用便携型LED蓝光治疗仪可安全治疗轻中度痤疮,明显降低痤疮引起的炎性皮损数目,且无明显副作用.

  12. Characterization of an Optical Device with an Array of Blue Light Emitting Diodes LEDS for Treatment of Neonatal Jaundice.

    Science.gov (United States)

    Sebbe, Priscilla Fróes; Villaverde, Antonio G. J. Balbin; Nicolau, Renata Amadei; Barbosa, Ana Maria; Veissid, Nelson

    2008-04-01

    Phototherapy is a treatment that consists in irradiating a patient with light of high intensity, which promotes beneficial photochemical transformations in the irradiated area. The phototherapy for neonates is applied to break down the bilirubin, an organic pigment that is a sub product of the erythrocytes degradation, and to increase its excretion by the organism. Neonates should be irradiated with light of wavelength that the bilirubin can absorb, and with spectral irradiances between 4 and 16 μW/cm2/nm. The efficiency of the treatment depends on the irradiance and the area of the body that is irradiated. A convenient source of light for treatment of neonatal jaundice is the blue Light Emitter Diode (LED), emitting in the range of 400 to 500 nm, with power of the order of 10-150 mW. Some of the advantages for using LEDS are: low cost, operating long lifetime (over 100,000 hours), narrow emission linewith, low voltage power supply requirement and low heating. The aim of this work was to build and characterize a device for phototherapy treatment of neonatal jaundice. This consists of a blanket with 88 blue LEDs (emission peak at 472 nm), arranged in an 8×11 matrix, all connected in parallel and powered by a 5V-2A power supply. The device was characterized by using a spectroradiometer USB2000 (Ocean Optics Inc, USA), with a sensitivity range of 339-1019 nm. For determination of light spatial uniformity was used a calibrated photovoltaic sensor for measuring light intensity and mapping of the light intensity spatial distribution. Results indicate that our device shows a uniform spatial distribution for distances from the blanket larger than 10 cm, with a maximum of irradiance at such a distance. This device presenting a large and uniform area of irradiation, efficient wavelength emission and high irradiance seems to be promising for neonates' phototherapy treatment.

  13. Photomorphogenesis, photosynthesis, and seed yield of wheat plants grown under red light-emitting diodes (LEDs) with and without supplemental blue lighting

    Science.gov (United States)

    Goins, G. D.; Yorio, N. C.; Sanwo, M. M.; Brown, C. S.; Sager, J. C. (Principal Investigator)

    1997-01-01

    Red light-emitting diodes (LEDs) are a potential light source for growing plants in spaceflight systems because of their safety, small mass and volume, wavelength specificity, and longevity. Despite these attractive features, red LEDs must satisfy requirements for plant photosynthesis and photomorphogenesis for successful growth and seed yield. To determine the influence of gallium aluminium arsenide (GaAlAs) red LEDs on wheat photomorphogenesis, photosynthesis, and seed yield, wheat (Triticum aestivum L., cv. 'USU-Super Dwarf') plants were grown under red LEDs and compared to plants grown under daylight fluorescent (white) lamps and red LEDs supplemented with either 1% or 10% blue light from blue fluorescent (BF) lamps. Compared to white light-grown plants, wheat grown under red LEDs alone demonstrated less main culm development during vegetative growth through preanthesis, while showing a longer flag leaf at 40 DAP and greater main culm length at final harvest (70 DAP). As supplemental BF light was increased with red LEDs, shoot dry matter and net leaf photosynthesis rate increased. At final harvest, wheat grown under red LEDs alone displayed fewer subtillers and a lower seed yield compared to plants grown under white light. Wheat grown under red LEDs+10% BF light had comparable shoot dry matter accumulation and seed yield relative to wheat grown under white light. These results indicate that wheat can complete its life cycle under red LEDs alone, but larger plants and greater amounts of seed are produced in the presence of red LEDs supplemented with a quantity of blue light.

  14. GaN-on-Si blue/white LEDs: epitaxy, chip, and package

    Science.gov (United States)

    Qian, Sun; Wei, Yan; Meixin, Feng; Zengcheng, Li; Bo, Feng; Hanmin, Zhao; Hui, Yang

    2016-04-01

    The dream of epitaxially integrating III-nitride semiconductors on large diameter silicon is being fulfilled through the joint R&D efforts of academia and industry, which is driven by the great potential of GaN-on-silicon technology in improving the efficiency yet at a much reduced manufacturing cost for solid state lighting and power electronics. It is very challenging to grow high quality GaN on Si substrates because of the huge mismatch in the coefficient of thermal expansion (CTE) and the large mismatch in lattice constant between GaN and silicon, often causing a micro-crack network and a high density of threading dislocations (TDs) in the GaN film. Al-composition graded AlGaN/AlN buffer layers have been utilized to not only build up a compressive strain during the high temperature growth for compensating the tensile stress generated during the cool down, but also filter out the TDs to achieve crack-free high-quality n-GaN film on Si substrates, with an X-ray rocking curve linewidth below 300 arcsec for both (0002) and (101¯2) diffractions. Upon the GaN-on-Si templates, prior to the deposition of p-AlGaN and p-GaN layers, high quality InGaN/GaN multiple quantum wells (MQWs) are overgrown with well-engineered V-defects intentionally incorporated to shield the TDs as non-radiative recombination centers and to enhance the hole injection into the MQWs through the via-like structures. The as-grown GaN-on-Si LED wafers are processed into vertical structure thin film LED chips with a reflective p-electrode and the N-face surface roughened after the removal of the epitaxial Si(111) substrates, to enhance the light extraction efficiency. We have commercialized GaN-on-Si LEDs with an average efficacy of 150–160 lm/W for 1mm2 LED chips at an injection current of 350 mA, which have passed the 10000-h LM80 reliability test. The as-produced GaN-on-Si LEDs featured with a single-side uniform emission and a nearly Lambertian distribution can adopt the wafer-level phosphor

  15. Biochemical, photosynthetic and productive parameters of Chinese cabbage grown under blue-red LED assembly designed for space agriculture

    Science.gov (United States)

    Avercheva, Olga; Berkovich, Yuliy A.; Smolyanina, Svetlana; Bassarskaya, Elizaveta; Pogosyan, Sergey; Ptushenko, Vasiliy; Erokhin, Alexei; Zhigalova, Tatiana

    2014-06-01

    Currently light emitting diodes (LEDs) are considered to be most preferable source for space plant growth facilities. We performed a complex study of growth and photosynthesis in Chinese cabbage plants (Brassica chinensis L.) grown with continuous LED lighting based on red (650 nm) and blue (470 nm) LEDs with a red to blue photon ratio of 7:1. Plants grown with high-pressure sodium (HPS) lamps were used as a control. PPF levels used were about 100 μmol/(m2 s) (PPF 100) and nearly 400 μmol/(m2 s) (PPF 400). One group of plants was grown with PPF 100 and transferred to PPF 400 at the age of 12 days. Plants were studied at the age of 15 and 28 days (harvest age); some plants were left to naturally end their life cycle. We studied a number of parameters reflecting different stages of photosynthesis: photosynthetic pigment content; chlorophyll fluorescence parameters (photosystem II quantum yield, photochemical and non-photochemical chlorophyll fluorescence quenching); electron transport rate, proton gradient on thylakoid membranes (ΔpH), and photophosphorylation rate in isolated chloroplasts. We also tested parameters reflecting plant growth and productivity: shoot and root fresh and dry weight, sugar content and ascorbic acid content in shoots. Our results had shown that at PPF 100, plants grown with LEDs did not differ from control plants in shoot fresh weight, but showed substantial differences in photophosphorylation rate and sugar content. Differences observed in plants grown with PPF 100 become more pronounced in plants grown with PPF 400. Most parameters characterizing the plant photosynthetic performance, such as photosynthetic pigment content, electron transport rate, and ΔpH did not react strongly to light spectrum. Photophosphorylation rate differed strongly in plants grown with different spectrum and PPF level, but did not always reflect final plant yield. Results of the present work suggest that narrow-band LED lighting caused changes in Chinese

  16. Photoluminescence Decay Dynamics in Blue and Green InGaN LED Structures Revealed by the Frequency-Domain Technique

    Science.gov (United States)

    Reklaitis, I.; Kudžma, R.; Miasojedovas, S.; Vitta, P.; Žukauskas, A.; Tomašiūnas, R.; Pietzonka, I.; Strassburg, M.

    2016-05-01

    An extended study of charge-carrier localization and delocalization in blue and green InGaN light-emitting diode (LED) test structures has been performed. Using the frequency-domain lifetime measurement (FDLM) technique based on direct harmonic modulation of photoluminescence excitation in the frequency range from 1 Hz to 100 MHz, carrier lifetimes were estimated at scales spanning from milliseconds to nanoseconds. The time resolution was determined using fast Fourier transform analysis. A system comprising a radiative and several nonradiative recombination channels was used to describe the complex photoluminescence decay. Due to the broad timescale, even stretched exponential decays from 2 ns to 4 ns up to 1.5 μs (stretching parameter 0.5 to 0.6) were revealed. A higher degree of carrier delocalization was observed for the blue compared with the green light-emitting structure, providing qualitative insight into disorder, which is tentatively assigned to spatial fluctuations of the indium concentration in the quantum wells. A nanosecond nonradiative recombination channel for the green light-emitting structure was found to be unsaturated throughout the entire photoexcitation power density range and was interpreted as being related to the higher defect density and lower internal quantum efficiency of the sample. To expand the study of lifetimes to much higher photoexcitation power density, time-resolved photoluminescence kinetics were measured.

  17. Photoluminescence Decay Dynamics in Blue and Green InGaN LED Structures Revealed by the Frequency-Domain Technique

    Science.gov (United States)

    Reklaitis, I.; Kudžma, R.; Miasojedovas, S.; Vitta, P.; Žukauskas, A.; Tomašiūnas, R.; Pietzonka, I.; Strassburg, M.

    2016-07-01

    An extended study of charge-carrier localization and delocalization in blue and green InGaN light-emitting diode (LED) test structures has been performed. Using the frequency-domain lifetime measurement (FDLM) technique based on direct harmonic modulation of photoluminescence excitation in the frequency range from 1 Hz to 100 MHz, carrier lifetimes were estimated at scales spanning from milliseconds to nanoseconds. The time resolution was determined using fast Fourier transform analysis. A system comprising a radiative and several nonradiative recombination channels was used to describe the complex photoluminescence decay. Due to the broad timescale, even stretched exponential decays from 2 ns to 4 ns up to 1.5 μs (stretching parameter 0.5 to 0.6) were revealed. A higher degree of carrier delocalization was observed for the blue compared with the green light-emitting structure, providing qualitative insight into disorder, which is tentatively assigned to spatial fluctuations of the indium concentration in the quantum wells. A nanosecond nonradiative recombination channel for the green light-emitting structure was found to be unsaturated throughout the entire photoexcitation power density range and was interpreted as being related to the higher defect density and lower internal quantum efficiency of the sample. To expand the study of lifetimes to much higher photoexcitation power density, time-resolved photoluminescence kinetics were measured.

  18. [The electroluminescence spectra of InGan/GaN blue LEDs during aging time].

    Science.gov (United States)

    Dai, Shuang; Yu, Tong-Jun; Li, Xing-Bin; Yuan, Gang-Cheng; Lu, Hui-Min

    2014-02-01

    The luminescence spectra of InGaN/GaN multiple quantum wells light-emitting diodes under low level injection current (measurement revealed that junction capacitance (C(j)) under the same junction voltage (V(j) = 1.8 V) and the junction voltage (V(j)) with the same injection current 1 mA calculated by ac small-signal IV method increased along with aging time, which explicates that the carrier density under the same low injection increases as the aging time increases. Analyses indicate that the polarization field in the quantum well is more seriously screened by the increased carriers captured by defects activated during stress time, the weaker effective polarization electric field makes the tilt of the energy band smaller, the energy radiated through the band edge and the density of energy states of the band edge increase which leads to the behaviors of peak wavelength and the FWHM of InGaN/GaN multiple quantum wells LEDs under low level injection current. PMID:24822394

  19. Light pollution modelling the UK Highways Agency new environmental policy, inc. astronomical impact of blue-rich LED luminaires.

    Science.gov (United States)

    Baddiley, Christopher James

    2015-08-01

    The Highways Agency are replacing their policy of full cut off class G6 road lighting specification on motorways (originally based on the author’s work), and are adopting a categorised environmental impact based point system that can accommodate technical advances, such as LED lighting. The Skyglow component of this will be based on the modelling of skyglow versus cut-off angle, developed for determining the relative light pollution environmental impact of different streetlight designs, by the author. Further modelling has been done concerning the effect of LED lighting, which potentially, has highly directional properties. But increasingly used blue rich colour temperatures may increase skyglow by 5 fold, compared to traditional lighting. This is due to enhanced reflection of vegetation and greatly increased atmospheric molecular Rayleigh scattering; a potential astronomical environmental disaster.Prior to this, the author carried out a dark sky survey of the Malvern Hills area of outstanding natural beauty (AONB), relating it to the same light pollution model. The results confirm the general predictions of the model and also clearly illustrate the relative significance of different designs of light sources at different distances, to the dark sky environment.The paper also briefly describes the results from the same model adapted to study the night-time environmental impact of a proposed very large sea based wind farm project in the English Channel, as a part of the planning process.

  20. Blue Light Hazard and Risk Group Classification of 8 W LED Tubes, Replacing Fluorescent Tubes, through Optical Radiation Measurements

    Directory of Open Access Journals (Sweden)

    Francesco Leccese

    2015-09-01

    Full Text Available In this paper, the authors discuss the results of a measurement survey of artificial optical radiation emitted by 8 W LED tubes suitable for the substitution of 18 W fluorescent lamps used for general lighting. For both types of lamps, three different color temperatures were chosen, 3000 K, 4000 K, and 6000 K. These measurements were performed to evaluate the photobiological safety of the sources. The radiance and irradiance values have been measured in a wide range of wavelengths (180–3000 nm. The measurement results obtained for the LED tubes have been compared to those of similar measurements obtained for fluorescent lamps. The analysis has been focused on the range of wavelengths 300–700 nm, the blue light range, which turned out to be defining for the risk groups of the lamps. This classification is a function of the maximum permissible exposure time as indicated in the European Standard EN 62471 on the photobiological safety of lamps and lamp systems.

  1. Biosorption of methyl blue onto tartaric acid modified wheat bran from aqueous solution

    Directory of Open Access Journals (Sweden)

    Yao Shuhua

    2012-12-01

    Full Text Available Abstract Tartaric acid modified wheat bran was utilized as adsorbent to remove methyl blue, a basic dye from aqueous solution. Batch experiments were carried out to study the effect of various experimental parameters such as initial solution pH, contact time, initial dye concentration and adsorbent dosage, on dye adsorption. The results showed that the modification of wheat bran by tartaric acid significantly improved its adsorption capacity, and made this material a suitable adsorbent to remove methyl blue. The adsorption capacity of modified wheat bran was about 1.6 times higher than that of unmodified one. The amount of methyl blue adsorbed was found to vary with initial solution pH, adsorbent dosage, contact time and initial methyl blue concentration. Kinetics study showed that the overall adsorption rate of methyl blue was illustrated by pseudo-second-order kinetic model. The applicability of the Langmuir and Freundlich models for the data was tested. Both models adequately described the experimental data of the biosorption of methyl blue. The maximum adsorption capacity for methyl blue calculated from Langmuir model was 25.18 mg/g. The study has shown the effectiveness of modified wheat bran in the removal of methyl blue, and that it can be considered as an attractive alternative to the more expensive technologies used in wastewater treatment.

  2. Biosorption of methyl blue onto tartaric acid modified wheat bran from aqueous solution.

    Science.gov (United States)

    Yao, Shuhua; Lai, Hong; Shi, Zhongliang

    2012-01-01

    Tartaric acid modified wheat bran was utilized as adsorbent to remove methyl blue, a basic dye from aqueous solution. Batch experiments were carried out to study the effect of various experimental parameters such as initial solution pH, contact time, initial dye concentration and adsorbent dosage, on dye adsorption. The results showed that the modification of wheat bran by tartaric acid significantly improved its adsorption capacity, and made this material a suitable adsorbent to remove methyl blue. The adsorption capacity of modified wheat bran was about 1.6 times higher than that of unmodified one. The amount of methyl blue adsorbed was found to vary with initial solution pH, adsorbent dosage, contact time and initial methyl blue concentration. Kinetics study showed that the overall adsorption rate of methyl blue was illustrated by pseudo-second-order kinetic model. The applicability of the Langmuir and Freundlich models for the data was tested. Both models adequately described the experimental data of the biosorption of methyl blue. The maximum adsorption capacity for methyl blue calculated from Langmuir model was 25.18 mg/g. The study has shown the effectiveness of modified wheat bran in the removal of methyl blue, and that it can be considered as an attractive alternative to the more expensive technologies used in wastewater treatment. PMID:23369295

  3. LED lamp

    Energy Technology Data Exchange (ETDEWEB)

    Galvez, Miguel; Grossman, Kenneth; Betts, David

    2013-11-12

    There is herein described a lamp for providing white light comprising a plurality of light sources positioned on a substrate. Each of said light sources comprises a blue light emitting diode (LED) and a dome that substantially covers said LED. A first portion of said blue light from said LEDs is transmitted through said domes and a second portion of said blue light is converted into a red light by a first phosphor contained in said domes. A cover is disposed over all of said light sources that transmits at least a portion of said red and blue light emitted by said light sources. The cover contains a second phosphor that emits a yellow light in response to said blue light. The red, blue and yellow light combining to form the white light and the white light having a color rendering index (CRI) of at least about 80.

  4. LED手电筒蓝光危害检测与分析%Test and Analysis on the Blue Light Hazard of LED Flashlights

    Institute of Scientific and Technical Information of China (English)

    胡苏军; 黄俊浩

    2015-01-01

    LED手电筒出射光束亮度大、色温高,蓝光发光成分位于400nm~500nm波段,蓝光辐射危害比较严重。依据国家标准GB/T 20145-2006,在0.2m和1.0m距离下,LED手电筒蓝光危害达到中度危险等级,如无防护措施可能对人眼造成严重伤害。分析发现,LED手电筒蓝光危害与手电筒的聚光性能、出射光束的亮度和色温密切相关。%The brightness and color temperature of LED flashlight beams are much higher, and the blue emission component located in the region of 400nm ~ 500nm, thus the blue light hazards of LED flashlights are more serious. According to the national standard, GB/T 20145-2006, the blue light hazards of LED flashlights can reach the moder-ate risk group under the distances of 0.2m and 1.0m; it may cause serious damage to human eyes without protective measures. Based on the analysis, we found out that the blue light hazard of LED flashlights is closely related to their light concentration properties, brightness and color temperature of beams.

  5. Hydrophilic Inorganic Macro-Ions in Solution: Unprecedented Self-Assembly Emerging from Historical "Blue Waters"

    Science.gov (United States)

    Liu, Tianbo; Diemann, Ekkehard; Muller, Achim

    2007-01-01

    For more than 200 years, the beautiful "molybdenum blue solutions" have been a puzzle for chemists because they could not determine the molecular structures of the solutes while experiments showing the Tyndall effect proved the presence of "giant species". This problem was finally solved in Bielefeld. As a result of this discovery, novel inorganic…

  6. Color temperature tunable white light LED system

    Science.gov (United States)

    Speier, Ingo; Salsbury, Marc

    2006-08-01

    Efficient white light LED systems with continuously tunable color temperature (CT) over a range of 3000 K to 6500 K are reviewed. Typically, white light sources have a fixed CT and color rendering index (CRI). White light with user-specified color temperatures is currently generated by solid-state systems with red green blue ("R/G/B"), red green blue amber ("R/G/B/A"), and warm white cool white ("WW/CW") LED combinations, but their performance is suboptimal for architectural lighting applications. We propose and discuss an LED module with a combination of warm white, green and blue ("WW/G/B") LEDs. In this scenario, the white LEDs have fixed intensity, while the blue and green LED intensities are adjusted to shift the LED module chromaticity along the blackbody locus. We also propose and discuss an LED module with a combination of red, green, blue, and cool white ("R/G/B/CW") LEDs. The white LEDs still have a fixed intensity, while the intensities of the red, green, and blue LEDs are again adjusted to shift the LED module chromaticity along the blackbody locus. The white LEDs ensure that an improved CRI is maintained in comparison to a simple "R/G/B" solution.

  7. Biosorption of Methyl Blue Onto Tartaric Acid Modified Wheat Bran From Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Shuhua Yao

    2012-12-01

    Full Text Available Tartaric acid modified wheat bran was utilized as adsorbent to remove methyl blue, a basic dye from aqueous solution. Batch experiments were carried out to study the effect of various experimental parameters such as initial solution pH, contact time, initial dye concentration and adsorbent dosage, on dye adsorption. The results showed that the modification of wheat bran by tartaric acid significantly improved its adsorption capacity, and made thismaterial a suitable adsorbent to remove 1.6 times higher than that of unmodified one. The amount of methyl blue adsorbed was found to vary with initial solution pH, adsorbent dosage, contact time and initial methyl blue concentration. Kinetics study showed that theoverall adsorption rate of methyl blue was illustrated by pseudo-second-order kinetic model. The applicability of theLangmuir and Freundlich models for the data was tested. Both models adequately described the experimental data of the biosorption of methyl blue. The maximum adsorption capacity for methyl blue calculated from Langmuir model was 25.18 mg/g. The study has shown the effectiveness of modified wheat bran in the removal of methylblue, and that it can be considered as an attractive alternative to the more expensive technologies used in wastewater treatment.

  8. Proposal of a mono-spectral imaging method for Blue Light Hazard evaluation on LED based luminaries

    International Nuclear Information System (INIS)

    IEC 62471 describes exposure limits to broad-spectrum incoherent optical radiation sources (UV, visible and IR). Its application seems particularly justified for the evaluation of White Phosphor-Coated Light-Emitting Diodes, which combine high luminance and a shortwave energy (blue)-rich spectrum, which potentially exposes the human eye to a Blue Light retinal Hazard. In theory, it is simply a question of measuring the spectral radiance of the light source inside the field of vision of the eye in movement then multiplying it with the function describing the Blue Light retinal Hazard. In practice, however, the measurement is not very repeatable in the case of inhomogeneous radiance. Protocols based on CCD imaging would probably improve the repeatability of measurements. This article deals with a first approach of a simple method for the evaluation of the Blue Light retinal Hazard by mono-spectral imaging. (authors)

  9. Synthesis and characterization of novel K2La2-xEuxTi3O10 phosphor for blue chip white LEDs

    Science.gov (United States)

    Grandhe, Bhaskar Kumar; Bandi, Vengala Rao; Jayasimhadri, M.; Jang, Kiwan; Lee, Ho-Sueb; Shin, Dong-Soo; Yi, Soung-Soo; Jeong, Jung-Hyun

    2013-05-01

    Eu3+ doped K2La2Ti3O10 (KLT) phosphors were prepared by means of conventional solid state reaction method. It has exhibited an intense excitation band at around 466 nm, which matches well to the popular emission line from a GaN based blue light-emitting diode (LED) chip. Using this as an excitation wavelength the Eu3+ doped KLT phosphors yielded two strong orange-red emission bands at 595 nm (5D0→7F1) and 616 nm (5D0→7F2) respectively. The obtained results suggest that Eu3+doped KLT phosphors are useful for blue chip white LEDs. Besides we have studied its dielectric properties along with the other significant characterizations like XRD, SEM and Tg-DTA.

  10. Bilirubin isomer distribution in jaundiced neonates during phototherapy with LED light centered at 497 nm (turquoise) vs. 459 nm (blue)

    DEFF Research Database (Denmark)

    Ebbesen, Finn; Madsen, Poul H; Vandborg, Pernille K;

    2016-01-01

    of jaundiced neonates after 24 h of therapy with narrow-band (LED) light centered at 497 nm (turquoise) vs. 459 nm (blue), of essentially equal irradiance. MATERIALS: Eighty-three neonates (≥33 wk gestational age) with uncomplicated hyperbilirubinemia were included in the study. Forty neonates were...... difference was found between concentrations of E,Z-lumirubin. CONCLUSION: Therapy with LED light centered at 497 nm vs. 459 nm, applied with equal irradiance on the infants, resulted in a different distribution of bilirubin isomers in serum.Pediatric Research (2016); doi:10.1038/pr.2016.115.......BACKGROUND: Phototherapy using blue light is the treatment of choice worldwide for neonatal hyperbilirubinemia. However, treatment with turquoise light may be a desirable alternative. Therefore, the aim of this randomized, controlled study was to compare the bilirubin isomer distribution in serum...

  11. Effects of the p-AlInGaN/GaN superlattices' structure on the performance of blue LEDs

    International Nuclear Information System (INIS)

    The advantages of the p-AlInGaN/GaN superlattices' (SLs) structure as an electron blocking layer (EBL) for InGaN blue light-emitting diodes (LEDs) were studied by experiment and APSYS simulation. Electroluminescence (EL) measurement results show that the LEDs with the p-AlInGaN/GaN SLs' structure EBL exhibited better optical performance compared with the conventional AlGaN EBL due to the enhancement of hole concentration and hole carrier transport efficiency, and the confinement of electrons' overflow between multiple quantum-wells (MQWs) and EBL. (semiconductor devices)

  12. Properties–structure relationship research on LiCaPO{sub 4}:Eu{sup 2+} as blue phosphor for NUV LED application

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinguo, E-mail: mpcc1@qq.com [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Mo, Fuwang; Zhou, Liya [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Gong, Menglian [State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2013-10-25

    Graphical abstract: The graphical abstract shows the excitation and emission spectrum of LiCaPO{sub 4}:Eu{sup 2+}, and the CIE coordinates of LiCaPO{sub 4}:Eu{sup 2+}. The inset shows the photo of blue LED prepared by LiCaPO{sub 4}:Eu{sup 2+} and NUV chip. It indicates that this phosphor can be excited by UV light and emit strong greenish-blue light. Highlights: •Pure phase blue phosphors of LiCaPO{sub 4}:Eu{sup 2+} with a hexagonal structure were first prepared via solid-state method. •The crystallographic site of Eu{sup 2+} ion in the LiCaPO{sub 4} lattice was identified as 8-fold Ca{sup 2+} site. •The phosphor exhibits excellent thermal stability and the corresponding mechanism was thermal assisted ionization. •Bright and high color purity blue LED prototype based on LiCaPO{sub 4}:Eu{sup 2+} phosphor was fabricated. -- Abstract: Blue-emitting phosphors of Eu{sup 2+}-activated LiCaPO{sub 4} with a hexagonal structure were prepared via a conventional solid-state method. The XRD, PL spectra and thermal quenching were applied to characterize the phosphors. The crystallographic site of Eu{sup 2+} ion in the LiCaPO{sub 4} lattice was identified and discussed. The optimized LiCaPO{sub 4}:0.03Eu{sup 2+} exhibits the bright greenish-blue emission with CIE coordinates of (0.119, 0.155) and a quantum efficiency of 52%. The critical energy-transfer distance was confirmed as ∼18 Å by both calculated crystal structure method and experimental spectral method. The thermal stability of LiCaPO{sub 4}:Eu{sup 2+} was evaluated by temperature-dependent PL spectra, and the thermal quenching mechanism was found to be thermal assisted ionization. Prototype blue LEDs with high color purity and good current stability were fabricated.

  13. Electrochemical Removal of Methylene Blue from Aqueous Solutions Using Taguchi Experimental Design

    OpenAIRE

    A ASghari; Kamalabadi, M.; Farzinia, H.

    2012-01-01

    Taguchi optimization method (L32 orthogonal array) was applied as an experimental design to determine optimum conditions for methylene blue dye removal from aqueous solutions by electrocoagulation (EC). Various electrocoagualtion parameters such as initial pH, time of electrolysis, concentration of dye, electrodes gap, applied current, solution temperature, amount of supporting electrolyte, design and materials of electrodes were investigated. The results have been analyzed using signal-to-no...

  14. All solution processed blue multi-layer light emitting diodes realized by thermal layer stabilization and orthogonal solvent processing

    Science.gov (United States)

    Nau, Sebastian; Trattnig, Roman; Pevzner, Leonid; Jäger, Monika; Schlesinger, Raphael; Nardi, Marco V.; Ligorio, Giovanni; Christodoulou, Christos; Schulte, Niels; Winkler, Stefanie; Frisch, Johannes; Vollmer, Antje; Baumgarten, Martin; Sax, Stefan; Koch, Norbert; Müllen, Klaus; List-Kratochvil, Emil J. W.

    2013-09-01

    Herein we report on the fabrication and the properties of two highly efficient blue light emitting multilayer polymer light emitting diodes (PLEDs). The first device structure combines a thermally stabilized polymer with a material processed from an orthogonal solvent, allowing for the fabrication of a triple layer structure from solution. The well known poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl)-diphenylamine) (TFB), which can be stabilized in a bake-out procedure, was used as a hole transporting layer. A novel pyrene - triphenylamine (PPyrTPA) copolymer was used as emissive layer. The stack was finalized by a poly(fluorene) - derivative with polar side-chains, therefore being soluble in a polar solvent which allows for the deposition onto PPyrTPA without redissolving. The resulting PLED showed bright-blue electroluminescence (CIE1931 coordinates x=0.163; y=0.216) with a high efficiency of 1.42 cd/A and a peak luminescence of 16500 cd/m². The second presented device configuration comprises a thermally stabilized indenofluorene - triphenylamine copolymer acting as hole transporter, and an emissive copolymer with building blocks specifically designed for blue light emission, effective charge carrier injection and transport as well as for exciton generation. This multilayer PLED led to deep-blue emission (CIE1931 x=0.144; y=0.129) with a remarkably high device efficiency of 9.7 cd/A. Additionally, atomic force microscopy was carried out to investigate the film morphology of the components of the stack and x-ray photoemission spectroscopy was performed to ensure a full coverage of the materials on top of each other. Ultraviolet photoemission spectroscopy confirmed the desired type-II band level offsets on the individual interfaces.

  15. High-efficiency blue LEDs with thin AlGaN interlayers in InGaN/GaN MQWs grown on Si (111) substrates

    Science.gov (United States)

    Kimura, Shigeya; Yoshida, Hisashi; Ito, Toshihide; Okada, Aoi; Uesugi, Kenjiro; Nunoue, Shinya

    2016-02-01

    We demonstrate high-efficiency blue light-emitting diodes (LEDs) with thin AlGaN interlayers in InGaN/GaN multiquantum wells (MQWs) grown on Si (111) substrates. The peak external quantum efficiency (EQE) ηEQE of 82% at room temperature and the hot/cold factor (HCF) of 94% have been obtained by using the functional thin AlGaN interlayers in the MQWs in addition to reducing threading dislocation densities (TDDs) in the blue LEDs. An HCF is defined as ηEQE(85°C)/ηEQE(25°C). The blue LED structures were grown by metal-organic chemical vapor deposition on Si (111) substrates. The MQWs applied as an active layer have 8- pairs of InGaN/AlyGa1-yN/GaN (0transmission electron microscopy and three-dimensional atom probe analysis that the 1 nm-thick AlyGa1-yN interlayers, whose Al content is y=0.3 or less, are continuously formed. EQE and the HCFs of the LEDs with thin Al0.15Ga0.85N interlayers are enhanced compared with those of the samples without the interlayers in the low-current-density region. We consider that the enhancement is due to both the reduction of the nonradiative recombination centers and the increase of the radiative recombination rate mediated by the strain-induced hole carriers indicated by the simulation of the energy band diagram.

  16. Adsorption of methylene blue from aqueous solution on zeolitic material for color and toxicity removal

    Directory of Open Access Journals (Sweden)

    Denise Alves Fungaro

    2011-03-01

    Full Text Available The adsorption of methylene blue (MB from aqueous solution was carried out using zeolite. This adsorbent material was synthesized from fly ash as a low-cost adsorbent, allowing fly ash to become a recycled residue. Factors that affected adsorption were evaluated: initial dye concentration, contact time and temperature. The equilibrium of adsorption was modeled by Langmuir, Freundlich and Temkin models. The adsorption obtained data were well described by Temkin, the adsorption isotherm model. Thermodynamic calculations suggest that the adsorption of methylene blue on zeolite synthesized from fly ash is a spontaneous and exothermic reaction. Acute toxicity was determined for raw and adsorbed methylene blue solutions, as if it was a real liquid residue. Acute effects were substantially reduced after the adsorption treatment. The values of untreated solution of methylene blue were 16.58 ppm up to 18.64 ppm for Vibrio fischeri bacteria and from 0.16 ppm up to 0.43 ppm for Daphnia similis cladoreca exposed to the dye for 48 hours.

  17. Specific staining of nuclei with aqueous solutions of celestin blue B and gallocyanine.

    Science.gov (United States)

    Dutt, M K

    1982-09-01

    This paper presents methods for specific staining of nuclei with aqueous solutions of celestin blue B and gallocyanine in tissue sections from which RNA has been extracted selectively with concentrated phosphoric acid at 5 degrees C for 20 min or by hydrolysis in 6 N HCl at 28 degrees C for 15 min. It has been found that pH of the freshly prepared celestin blue B dye solution is 3.0 and that of an aqueous solution of gallocyanine is 2.8. These pHs can be lowered to 1.5 with concentrated sulphuric or nitric acid and at this pH staining of the nuclei is possible. But with concentrated sulphuric or nitric acid and at this pH staining of the nuclei is possible. But if the pHs are lowered with concentrated hydrochloric or phosphoric acid, effective use of these dyes is not possible. It has been suggested that some dispersion of the two dyes takes place with concentrated sulphuric or nitric acid which are used to lower the pH. Staining of the nuclei is also possible with an aqueous solution of celestin blue B at pH 3.0 but the same is not possible with gallocyanine at pH 2.8. The absorption spectra of nuclei stained with an aqueous solution of celestin blue B at pH 1.5 and 3.0 are fairly identical, the peak of maximum absorption being at 620 nm. Those of nuclei stained with an aqueous solution of gallocyanine reveal irregular peaks. Possible implications of these findings have been discussed. PMID:6183561

  18. Adsorption of methylene blue from aqueous solution on zeolitic material for color and toxicity removal

    OpenAIRE

    Denise Alves Fungaro; Lucas Caetano Grosche; Alessandro Pinheiro; Juliana de Carvalho Izidoro; Sueli Ivone Borrely

    2011-01-01

    The adsorption of methylene blue (MB) from aqueous solution was carried out using zeolite. This adsorbent material was synthesized from fly ash as a low-cost adsorbent, allowing fly ash to become a recycled residue. Factors that affected adsorption were evaluated: initial dye concentration, contact time and temperature. The equilibrium of adsorption was modeled by Langmuir, Freundlich and Temkin models. The adsorption obtained data were well described by Temkin, the adsorption isotherm model....

  19. Experimental and numerical study on a micro jet cooling solution for high power LEDs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An active cooling solution based on close-looped micro impinging jet is proposed for high power light emitting diodes (LEDs). In this system, a micro pump is utilized to enable the fluid circulation, impinging jet is used for heat exchange between LED chips and the present system. To check the feasibility of the present cooling system, the preliminary experiments are conducted without the intention of parameter opti-mization on micro jet device and other system components. The experiment results demonstrate that the present cooling system can achieve good cooling effect. For a 16.4 W input power, the surface temperature of 2 by 2 LED array is just 44.2℃ after 10 min operation, much lower than 112.2℃, which is measured without any active cool-ing techniques at the same input power. Experimental results also show that increase in the flow rate of micro pump will greatly enhance the heat transfer efficiency, how-ever, it will increase power consumption. Therefore, it should have a trade-off be-tween the flow rate and the power consumption. To find a suitable numerical model for next step parameter optimization, numerical simulation on the above experiment system is also conducted in this paper. The comparison between numerical and ex-periment results is presented. For two by two chip array, when the input power is 4 W, the surface average temperature achieved by a steady numerical simulation is 34℃, which is close to the value of 32.8℃ obtained by surface experiment test. The simu-lation results also demonstrate that the micro jet device in the present cooling sys-tem needs parameter optimization.

  20. Experimental and numerical study on a micro jet cooling solution for high power LEDs

    Institute of Scientific and Technical Information of China (English)

    LUO XiaoBing; LIU Sheng; JIANG XiaoPing; CHENG Ting

    2007-01-01

    An active cooling solution based on close-looped micro impinging jet is proposed for high power light emitting diodes (LEDs). In this system, a micro pump is utilized to enable the fluid circulation, impinging jet is used for heat exchange between LED chips and the present system. To check the feasibility of the present cooling system, the preliminary experiments are conducted without the intention of parameter optimization on micro jet device and other system components. The experiment results demonstrate that the present cooling system can achieve good cooling effect. For a 16.4 W input power, the surface temperature of 2 by 2 LED array is just 44.2℃ after 10 min operation, much lower than 112.2℃, which is measured without any active cooling techniques at the same input power. Experimental results also show that increase in the flow rate of micro pump will greatly enhance the heat transfer efficiency, however, it will increase power consumption. Therefore, it should have a trade-off between the flow rate and the power consumption. To find a suitable numerical model for next step parameter optimization, numerical simulation on the above experiment system is also conducted in this paper. The comparison between numerical and experiment results is presented. For two by two chip array, when the input power is 4 W, the surface average temperature achieved by a steady numerical simulation is 34℃, which is close to the value of 32.8℃ obtained by surface experiment test. The simulation results also demonstrate that the micro jet device in the present cooling system needs parameter optimization.

  1. Effect of red and blue light emitting diodes "CRB-LED" on in vitro organogenesis of date palm (Phoenix dactylifera L.) cv. Alshakr.

    Science.gov (United States)

    Al-Mayahi, Ahmed Madi Waheed

    2016-10-01

    The objective of the present study is to determine the effect of light source on enhancement of shoot multiplication, phytochemicals, as well as, antioxidant enzyme activities of in vitro cultures of date palm cv. Alshakr. In vitro-grown buds were cultured on Murashige and Skoog (MS) medium and incubated under a conventional white fluorescent light (control), and combinations of red + blue light emitting diode (18:2) (CRB-LED). Results revealed that the treatment of CRB-LED showed a significant increase in the number of shoots compared with the white florescent light. Total soluble carbohydrate "TSCH" (7.10 mg g(-1) DW.), starch (1.63 mg g(-1) DW.) and free amino acids (2.90 mg g(-1) DW.) were significantly higher in CRB-LED (p fluorescent light treatment (19.74 U ml(-1)) as control treatment. Potassium, magnesium and sodium contents in (3.62, 13.99 and 2.76 mg g(-1) DW.) were increased in in vitro shoots under CRB-LED treatment in comparison with fluorescent light (p light during the course of date palm tissue cultures. PMID:27562594

  2. ‘No Blue’ White LED

    DEFF Research Database (Denmark)

    Ou, Haiyan; Corell, Dennis Dan; Dam-Hansen, Carsten;

    2010-01-01

    . Gretagmacbeth color charts were used as a more visual way to compare the two light sources, which shows that our no-blue LED bulb has much better color rendering ability than the YFT. Furthermore, LED solution has design flexibility to improve it further. The prototype has been tested with photoresist SU8......This paper explored the feasibility of making a white LED light source by color mixing method without using the blue color. This ‘no blue’ white LED has potential applications in photolithography room illumination, medical treatment and biophotonics research. A no-blue LED was designed......, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that, colorimetric values were calculated and compared on terms of chromatic coordinates, correlated color temperature, color rendering index, and chromatic deviation...

  3. Light extraction efficiency enhancement of GaN-based blue LEDs based on ITO/ InxO ohmic contacts with microstructure formed by annealing in oxygen.

    Science.gov (United States)

    Luo, Yi; Bai, Yiming; Han, Yanjun; Li, Hongtao; Wang, Lai; Wang, Jian; Sun, Changzheng; Hao, Zhibiao; Xiong, Bing

    2016-05-16

    Indium tin oxide (ITO)/ indium oxide (InxO) double layer structure was adopted as the transparent conduction and light scattering function layer to improve the light extraction efficiency of the GaN-based blue LEDs. The double layer structure was first deposited in one run by electron beam evaporation using ITO and Indium as the source respectively, and then annealed in an oxygen environment. This method can fabricate transparent electrode with microstructure and low specific contact resistivity one time free from lithography and etching, which makes the fabrication process simple and at a ower cost. For the 220 nm ITO/ 170 nm InxO double layer sample annealed at 600°C for 15 min in oxygen, measurement results show that its root mean square of roughness of the surface microstructure can be as high as 85.2 nm which introduces the strongest light scattering. Its light transmittance at 450 nm can maintain 92.4%. At the same time, it can realize lower specific contact resistivity with p-InGaN. Compared with the GaN-based blue LEDs with only 220 nm ITO electrode, the light output power of the LEDs with 220 nm ITO/ 170 nm InxO double layer structure can be increased about 58.8%, and working voltage at 20 mA injection current is decreased about 0.23 V due to the enhanced current spreading capability. The light output power improvement is also theoretically convinced by finite difference time domain simulations. PMID:27409953

  4. Biosorption of C.I. Direct Blue 199 from aqueous solution by nonviable Aspergillus niger

    International Nuclear Information System (INIS)

    The capacity and mechanism with which nonviable Aspergillus niger removed the textile dye, C.I. Direct Blue 199, from aqueous solution was investigated using different parameters, such as initial dye concentration, pH and temperature. In batch experiments, the biosorption capacity increased with decrease in pH, and the maximum dye uptake capacity of the biosorbent was 29.96 mg g-1 at 400 mg L-1 dye concentration and 45 deg. C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of C.I. Direct Blue 199 onto the fungal biomass. Biosorption followed a pseudo-second order kinetic model with high correlation coefficients (r2 > 0.99). Thermodynamic studies revealed that the biosorption process was successful, spontaneous and endothermic in nature.

  5. Size effect on negative capacitance at forward bias in InGaN/GaN multiple quantum well-based blue LED

    Science.gov (United States)

    Bourim, El-Mostafa; Han, Jeong In

    2016-01-01

    Size effect of InGaN/GaN multiple quantum well (MQW) blue light emitting diodes (LEDs), on electrical characteristics in forward bias voltage at high injection current in light emission regime, is observed to induce a substantial dispersion in the current density and normalized negative capacitance (NC) (i.e., capacitance per chip area). The correction of normalized NC by considering the LED p- n junction series resistance has been found to be independent of chip area size with lateral dimensions ranging from 100 µm × 100 µm to 400 µm × 400 µm. This fact, confirms that the inductive effect which is usually behind the NC apparition is homogeneously and uniformly distributed across the entire device area and hence the dispersive characteristics are not related to local paths. From the characteristics of NC dependence on temperature, frequency and direct current bias, a mechanism based on the electrons/holes charge carriers conductivity difference is proposed to be responsible for the transient electron-hole pair recombination process inducing NC phenomenon. Direct measurement of light emission brightness under modulated frequency demonstrated that modulated light output evolution follows the same behavioral tendency as measured in NC under alternating current signal modulation. Thus it is concluded that the NC is valuable information which would be of practical interest in improving the characteristics and parameters relevant to LED p- n junction internal structure. [Figure not available: see fulltext.

  6. Adsorption of Methylene Blue from Aqueous Solution onto a Low-Cost Natural Jordanian Tripoli

    Directory of Open Access Journals (Sweden)

    Atef S. ALzaydien

    2009-01-01

    Full Text Available Background: Dyes and pigments are widely used, mostly in the textiles, paper, plastics, leather, food and cosmetic industry to color products. The release of colored wastewater from these industries may present an eco-toxic hazard. Various techniques like precipitation, ion exchange, chemical oxidation, and adsorption have been used for the removal of toxic pollutant from, wastewater. Methylene blue (MB is selected as a model compound for evaluating the potential of tripoli to remove dye from wastewaters. Objective: In this study, Jordanian low- cost locally available tripoli was studied for its potential use as an adsorbent for removal of a cationic dye (methylene blue,MB from aqueous solution. Factors affecting adsorption, such as , initial dye concentration, pH, contact time , adsorbent dose and temperature, were evaluated. The equilibrium of adsorption was modelled by using the Langmuir , Freundlich, Temkin and Dubinin-Radushkevich isotherm models, the kinetic parameters and intraparticle diffusion were also then determined for the methylene blue-tripoli system. Methodology: The raw tripoli samples were kindly supplied by the Authority of Natural Resources (Jordan, Amman. X-ray diffraction spectroscopy (XRD analysis was carried out with PANalytical X-ray, Philips Analytical. Fourier transform infrared spectrophotometry (FT-IR analysis was conducted. The cation exchange capacity (CEC of tripoli was estimated using The copper bis-ethylenediamine complex method. The specific surface area of tripoli was estimated using Sears’ method by agitating 1.5 g of the tripoli sample in 100 ml of diluted hydrochloric acid of a pH = 3. Adsorption equilibrium studies were carried out by adding 0.5 g of tripoli in a series of 250mL flasks containing 100mL of MB solution of different dye concentrations at four different temperatures (20, 30, and 50 ◦C. The experiments of adsorption kinetics were carried out in stirred batch mode. For each experiment, 0.1 L

  7. Biosorption of Methylene Blue from Aqueous Solutions by Diospyrous melanoxylon Leaf Waste

    Directory of Open Access Journals (Sweden)

    Raghvendra G Patil

    2013-04-01

    Full Text Available Waste Tendu (Diospyros melanoxylon leaves from bidi (local cigarette industry has been used as a raw material to produce activated carbon applying sulfuric acid carbonization method. Batch experiments were conducted to assess the potential for the removal of methylene blue dye from aqueous solution using the activated carbon and compared to raw tendu leaves powder and commercial activated carbon. Equilibrium isotherm and kinetic studies have been done by varying the parameters such initial concentration of dye, adsorbent dose, pH of the dye solution, and varying the contact time between the carbon and the dye. It was found that the methylene blue adsorption on tendu waste-based activated carbon conformed to the Langmuir isotherm. The maximum monolayer adsorption capacities were found to be 219.3, 355.9 and 495.1 mg/g for raw tendu waste, carbonized tendu and commercial carbon, respectively. The kinetic studies were well characterized by a pseudo second order kinetic model. The results of this study indicate that raw tendu waste a renewable bioresource, as such as well as its carbonized form are attractive biosorbent for removing a cationic dye from the dye wastewater.DOI: http://dx.doi.org/10.5755/j01.erem.63.1.2735

  8. γ-ray induced degradation of reactive blue KNR in aqueous solution

    International Nuclear Information System (INIS)

    The textile industry has been recognized as one of the largest pollution sources of wastewater in China. In this study, the possibility of using irradiation technology to degrade reactive dye in aqueous solution was investigated. The reactive blue KNR in aqueous solutions under different conditions were irradiated by 60Co γ-rays to 4.3, 8.9, 13.7, 17.4 and 20.3 kGy, respectively. Changes of absorption spectra, chemical oxygen demand (COD) and degree of decoloration were examined. A COD removal efficiency of 80% and a decoloration rate of 100% could be obtained. The results suggests that the irradiation technology shall be a promising process for treatment of textile dye waste effluents

  9. Inherent calibration of a blue LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    Directory of Open Access Journals (Sweden)

    R. Thalman

    2010-12-01

    Full Text Available The combination of Cavity Enhanced Absorption Spectroscopy (CEAS with broad-band light sources (e.g. Light-Emitting Diodes, LEDs lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0. We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420–490 nm to measure nitrogen dioxide (NO2, glyoxal (CHOCHO, methyl glyoxal (CH3COCHO, iodine oxide (IO, water vapour (H2O and oxygen dimers (O4. We demonstrate the first direct detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. The instrument is further inherently calibrated for light extinction from the cavity by observing O4 or H2O (at 477 nm and 443 nm and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3–7 × 10−7cm−1. Excellent agreement is found from both the O4 and H2O retrievals. This enables the first inherently calibrated CEAS measurement at blue wavelengths in open cavity mode, and eliminates the need for sampling lines to supply air to the cavity, i.e., keep the cavity enclosed and/or aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH3COCHO, NO2, H2O and aerosol extinction. Our prototype

  10. Solution of multi-element LED light sources development automation problem

    Science.gov (United States)

    Chertov, Aleksandr N.; Gorbunova, Elena V.; Korotaev, Valery V.; Peretyagin, Vladimir S.

    2014-09-01

    The intensive development of LED technologies resulted in the creation of multicomponent light sources in the form of controlled illumination devices based on usage of mentioned LED technologies. These light sources are used in different areas of production (for example, in the food industry for sorting products or in the textile industry for quality control, etc.). The use of LED lighting products in the devices used in specialized lighting, became possible due to wide range of colors of light, LED structures (which determines the direction of radiation, the spatial distribution and intensity of the radiation, electrical, heat, power and other characteristics), and of course, the possibility of obtaining any shade in a wide dynamic range of brightness values. LED-based lighting devices are notable for the diversity of parameters and characteristics, such as color radiation, location and number of emitters, etc. Although LED technologies have several advantages, however, they require more attention if you need to ensure a certain character of illumination distribution and/or distribution of the color picture at a predetermined distance (for example, at flat surface, work zone, area of analysis or observation). This paper presents software designed for the development of the multicomponent LED light sources. The possibility of obtaining the desired color and energy distribution at the zone of analysis by specifying the spatial parameters of the created multicomponent light source and using of real power, spectral and color parameters and characteristics of the LEDs is shown as well.

  11. Removal of the blue 1 dye of aqueous solutions using ferric zeolite

    International Nuclear Information System (INIS)

    Water is essential to all life forms, including humans. In recent years water use has increased substantially, also has been altered in its capacity as a result of various human activities, such as domestic, industrial and agricultural, also by natural activity. Undoubtedly one of the main pollutants today are the waste generated by the food industry, due to the use of dyes for the production of their products. So it is necessary to restore water quality through treatment systems to remove contaminants, and thus prevent disease and imbalance of ecosystems. Due to the above, it is important to conduct research directed towards finding new ways to remove dyes such as blue 1 used in the food industry, using low cost materials and abundant in nature as zeolites. To accomplish the above, the present study has the purpose to evaluate the adsorption capacity of the blue dye 1 in aqueous solutions. To accomplish that objective, the zeolite material was reconditioned to improve its sorption properties of the material and provide the ability to adsorb pollutants such as this dye. The zeolite material was characterized by scanning electron microscopy and elemental analysis, X-ray diffraction and infrared spectroscopy. To evaluate the ability of blue 1 dye sorption the kinetics and sorption isotherms were determined; the experimental results were adjusted to mathematical models such as pseudo-first order, pseudo second order and Elovich to describe the kinetic process, and the Langmuir, Freundlich and Langmuir-Freundlich to describe sorption isotherms. The results showed that ferric zeolite surface is a heterogeneous material and has a considerable adsorption capacity, which makes it a potential adsorbent for removing color from aqueous streams. Also the sorption of the dye was evaluated at different ph values; the most sorption was carried out at ph values 1, 3 and 11. We also evaluated the change in mass where the sorption capacities for the blue 1 increase by increasing

  12. A new structure of p-GaN/InGaN heterojunction to enhance hole injection for blue GaN-based LEDs

    Science.gov (United States)

    Lin, Zhiting; Wang, Haiyan; Lin, Yunhao; Yang, Meijuan; Li, Guoqiang; Xu, Bingshe

    2016-07-01

    A new structure of p-GaN/InGaN heterojunction has been proposed to enhance hole injection for blue GaN-based light-emitting diodes (LEDs). It is demonstrated by the simulation results that a p-GaN (50 nm)/In0.05Ga0.95N (150 nm) heterojunction can make a 25% and 10% increment of hole and electron concentration in the active region, respectively, finally resulting in a 55% improvement on the LED’s radiative recombination intensity. The simulation also reveals that the efficiency droop is alleviated from 32.9% to 21.7% at the current density of 100 A cm‑2. The enhanced hole injection is mainly attributed to the increased average background hole concentration of the area between the p-AlGaN electron blocking layer (EBL) to the p-GaN/InGaN heterojunction. The increasing potential barrier of the conduction band, resulting from the introduction of p-GaN/InGaN heterojunction, would also weaken electron leakage and is favorable to the LED’s luminous performance. The experimental results show that the wall-plug efficiency (WPE) of the p-GaN/InGaN LED increases by 26.0% at the injection current of 75 mA, in spite of the increasing electric resistance, which impairs the improvement of the LED’s performance from the enhanced hole injection. The structure of the p-GaN/InGaN heterojunction is novel in the field of p-type region design, and is a simple but effective way to promote the LED’s performance, which is very promising for application in further high-performance LED fabrication.

  13. Adsorption of methylene blue and Congo red from aqueous solution by activated carbon and carbon nanotubes.

    Science.gov (United States)

    Szlachta, M; Wójtowicz, P

    2013-01-01

    This study was conducted to determine the adsorption removal of dyes by powdered activated carbon (PAC, Norit) and multi-walled carbon nanotubes (MWCNTs, Chinese Academy of Science) from an aqueous solution. Methylene blue (MB) and Congo red (CR) were selected as model compounds. The adsorbents tested have a high surface area (PAC 835 m(2)/g, MWCNTs 358 m(2)/g) and a well-developed porous structure which enabled the effective treatment of dye-contaminated waters and wastewaters. To evaluate the capacity of PAC and MWCNTs to adsorb dyes, a series of batch adsorption experiments was performed. Both adsorbents exhibited a high adsorptive capacity for MB and CR, and equilibrium data fitted well with the Langmuir model, with the maximum adsorption capacity up to 400 mg/g for MB and 500 mg/g for CR. The separation factor, RL, revealed the favorable nature of the adsorption process under experimental conditions. The kinetics of adsorption was studied at various initial dye concentrations and solution temperatures. The pseudo-second-order model was used for determining the adsorption kinetics of MB and CR. The data obtained show that adsorption of both dyes was rapid in the initial stage and followed by slower processing to reach the plateau. The uptake of dyes increased with contact time, irrespective of their initial concentration and solution temperature. However, changes in the solution temperature did not significantly influence dye removal. PMID:24292474

  14. Removal of methylene blue dye from aqueous solutions by elaeagnusan gastifolial as an adsorbent

    Directory of Open Access Journals (Sweden)

    Rezvan Zeynolabedin

    2015-03-01

    Full Text Available Batch experiments were carried out for the sorption of methylene blue onto elaeagnusan gastifolial particles. The operating variables studied were initial solution pH, contact time, adsorbent dosage and temperature. Equilibrium data were fitted to Freundlich and Langmuir isotherm equation and the equilibrium data were found to well represented by Langmuir isotherm equation. Various thermodynamic parameters such as enthalpy of sorption (∆H°, free energy change (∆G° and entropy (∆S° were estimated. The positive value of ∆H° and negative value of ∆G° shows the sorption process is endothermic and spontaneous. The positive value of entropy ∆S° shows the increased randomness at the solid–liquid interface during the sorption of dye ions onto elaeagnusan gastifolial particles.

  15. Large-scale dosimetry using dilute methylene blue dye in aqueous solution

    International Nuclear Information System (INIS)

    The radiolytic bleaching of neat aerated methylene blue solutions is relatively stable, when irradiated to doses in the range of 50 to 500 Gy and measured at the main peak of absorption band of the dye (664 nm). The useful range can be extended up to about 5 kGy if the aqueous dye solution contains about 0.1% ethanol by volume and to 10 kGy with 5% ethanol. By increasing the concentration of the dye in the presence of 5% ethanol doses up to about 30 kGy can be measured. The spectrophotometric readings have to be made during a period of post irradiation stability of 24 hours, after which there is about a 10% increase in absorbance over the next three days due to regeneration of the dye by spontaneous oxidation. Since the industrial grade monovalent dye salt is very inexpensive and is relatively non-toxic, it may be used for dosimetry studies in quality control tests of electron beam processing of large volumes of waste water, when typical doses in the range of 5-30 kGy are required. The influences of dose, dose rate and solute concentration on the bleaching process have been investigated in terms of the decrease of the absorbance of the dye

  16. Methylene blue adsorption of GMZ bentonite and the effect of hyper-alkaline solution erosion

    International Nuclear Information System (INIS)

    The method of combining the halo method with the spectrometer method, was used to study on the Methylene blue (MB) adsorption of Gaomiaozi (GMZ) bentonite, which had been eroded by hyper-alkaline solution, to investigate the mechanism of the effect of hyper-alkaline pore water on the buffer/backfill properties of GMZ bentonite. Results present, method employed in this article is brief and feasible, and high accuracy; The total specific surface area calculated by the test of MB adsorption is more accurate than the method of ethylene glycol monomethyl ether (EGIVIE). The MB adsorption of samples, which had been eroded by hyper-alkaline solution, decreases with the increase of the concentration of hyper-alkaline solution, and the change law agrees with the variation of the mass percentage of montmorillonite in bentonite tested by X- Ray diffraction (XRD). Therefore, the erosion of hyper-alkaline pore water might dissolve montmorillonite, which is the effective composition of bentonite, and destroy the tetrahedron- octahedron-tetrahedron (T-O-T) structure of montmorillonite, then lead to the decrease of cation exchange capability and the specific surface area of montmorillonite, and the the macroscopic expressions are the decrease of MB adsorption, the swelling potential and the increase of permeability. (authors)

  17. Adsorption of Methylene Blue from Aqueous Solutions by Polyvinyl Alcohol/Graphene Oxide Composites.

    Science.gov (United States)

    Yang, Xiaoxia; Li, Yanhui; Du, Qiuju; Wang, Xiaohui; Hu, Song; Chen, Long; Wang, Zonghua; Xia, Yanzhi; Xia, Linhua

    2016-02-01

    As a new member of the carbon family, graphene oxide (GO) has shown excellent adsorption ability to micro-pollutants in aqueous solutions. However, its tiny size makes it difficult to be removed from aqueous solutions using the conventional separation methods, which limits its practical application in the environmental protection. In this study, polyvinyl alcohol (PVA) was used as carrier immobilizing GO, and novel PVA/GO composites were prepared. The morphology and physicochemical properties of the composites were characterized by SEM, FTIR and TGA analysis. The adsorption properties of methylene blue (MB) onto the composites were studied through investigating the experimental parameters such as solution pH, adsorbent dosage, contact time and temperature. The isotherm data were analyzed using the Langmuir, Freundlich and Dubinin-Radushkevich models. The calculated maximum adsorption capacity reached 476.2 mg/g at 50% GO content. The pseudo-first-order kinetic, pseudo-second-order kinetic and intra-particle diffusion models were used to explore the adsorption kinetics. The results showed that the dynamic data were fitted to the pseudo-second-order kinetic model. PMID:27433669

  18. Enhanced orange-red emission from KSrVO4:Sm3+ nanophosphor for possible application in blue light-emitting diode based white LED

    International Nuclear Information System (INIS)

    In this paper, the combustion synthesis and photoluminescence properties of Sm3+ doped KSrVO4 nanophosphors are reported. The samples were characterized by different techniques such as x-ray powder diffraction, transmission electron microscopy, UV–vis spectrophotometry and photoluminescence spectroscopy. The lattice parameters were calculated as a=7.4688 (4) A-ring ´, b=5.8171 (4) A-ring ´, c=9.9490 (5) A-ring ´ and V=432.2485 (5) Ǻ3. The average grain size of the samples was estimated as 42 nm using the modified Scherrer’s equation. Under near UV excitation, the sharp emission line at 560, 600, 646 and 704 nm due to characteristic transitions of Sm3+ were observed. The maximum PL emission intensity was observed at 1.5 mol.% of the Sm3+ ions. The band gap of the phosphor was calculated from diffused reflectance data and was found to be 3.74 eV. The CIE 1931 chromaticity coordinates (x, y) of the phosphor were (0.61, 0.39), in a shade of orange-red color. The potential applications of this material as a down conversion phosphor under blue light excitation were evaluated for possible application as a high color-purity phosphor in light emitting diodes (LEDs) that can fill the 590–600 nm gap. (paper)

  19. Effect of solution temperature on methylene blue degradation in glow corona discharge reactor

    Energy Technology Data Exchange (ETDEWEB)

    Benetoli, L.O.B.; Cadorin, B.M.; Goncalves de Souza, I.; Debacher, N.A. [Federal Univ. of Santa Catarina, Florianopolis, Santa Catarina (Brazil). Dept. of Chemistry

    2010-07-01

    Non-thermal plasma (NTP) is an emerging technology for water cleaning that can be used in several environmental and industrial processes. Electrical discharges above or below the water surface cause chemical activation of a system through the production of strong oxidant species in solution that can be used to break down and remove toxic organic contaminants such as dyes, phenols or aromatic ammines that are present in the aqueous phase. This study investigated the effect of bath solution temperature on methylene blue (MB) degradation in a point-to-plate glow corona discharge (GCD) reactor. MB is used to mediate electron transfer in microbial fuel cells. The activation energy involved in the dye degradation was estimated in order to better understand the chemical processes taking place in the liquid phase triggered by the NTP discharge. The plasma channels were created in the nitrogen gas phase above the solution surface. The bath solution temperature varied between 4 to 47 degrees C. The dye removal percentage increased as the bath temperature increased except at 47 degrees C, when a decrease in the MB removal was observed. The formation of hydrogen peroxide (H{sub 2}O{sub 2}) increased as the bath temperature decreased. The maximum H{sub 2}O{sub 2} concentration was observed at 4 degrees C. This effect may be related to the viscosity and diffusion coefficients of water and dye/H{sub 2}O{sub 2} molecules. This paper also presented the activation energy of the GCD process as determined by the Arrhenius equation. 11 refs., 1 tab., 6 figs.

  20. Biosorption of methylene blue from aqueous solutions by a waste biomaterial: hen feathers

    Science.gov (United States)

    Chowdhury, Shamik; Saha, Papita Das

    2012-09-01

    Biosorption potential of hen feathers (HFs) to remove methylene blue (MB) from aqueous solutions was investigated. Batch experiments were carried out as function of different process parameters such as pH, initial dye concentration, biosorbent dose and temperature. The optimum conditions for removal of MB were found to be pH 7.0, biosorbent dose = 1.0 g, and initial dye concentration = 50 mg L-1. The temperature had a strong influence on the biosorption process. Experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms with the Langmuir isotherm showing the best fit at all temperatures studied. The maximum monolayer sorption capacity was determined as 134.76 mg g-1 at 303 K. According to the mean free energy values of sorption ( E) calculated using the D-R isotherm model, biosorption of MB onto HFs was chemisorption. Kinetic studies showed that the biosorption of MB followed pseudo second-order kinetics. The activation energy ( E a) determined using the Arrhenius equation confirmed that the biosorption involved chemical ion-exchange. Thermodynamic studies showed that the biosorption process was spontaneous and exothermic. To conclude, HFs is a promising biosorbent for MB removal from aqueous solutions.

  1. Removal of methylene blue from aqueous solution by fibrous clay minerals

    International Nuclear Information System (INIS)

    Kinetics and equilibrium processes of the methylene blue (MB) retention from aqueous solution by a mixture of fibrous clay minerals, which was isolated from a naturally occurring clay, were investigated. For these purposes, the effects of contact time, initial adsorbate concentration, adsorbent content, pH and ionic strength were determined. The results show that the MB retention obeys a pseudo-first order equation and the process is a diffusion controlled solid-state reaction. Moreover, the isotherm data fitted the Langmuir equation and the MB binding process became more energetic with the increase of the adsorbent concentration. In addition, the augmentation of the clay content or the initial MB concentration reduced the adsorption capacity, presumably because of the clay particles microaggregation and/or the occurrence of MB deriving species. On the other hand, it is observed that the MB uptake limit is reduced in low acid pH, particularly below the PZC, as well as in ionic strengthen solutions. These facts are linked to the silanol group protonation and to the reduction of the electrostatic forces induced by the clay particles, respectively

  2. Removal of Methylene Blue from Aqueous Solution by Activated Carbon Prepared from Pea Shells (Pisum sativum

    Directory of Open Access Journals (Sweden)

    Ünal Geçgel

    2013-01-01

    Full Text Available An activated carbon was prepared from pea shells and used for the removal of methylene blue (MB from aqueous solutions. The influence of various factors such as adsorbent concentration, initial dye concentration, temperature, contact time, pH, and surfactant was studied. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. The adsorption isotherm was found to follow the Langmuir model. The monolayer sorption capacity of activated carbon prepared from pea shell for MB was found to be 246.91 mg g−1 at 25 ∘C. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. Kinetic studies showed that the adsorption followed pseudo-second-order kinetic model. Various thermodynamic parameters such as , , and were evaluated. The results in this study indicated that activated carbon prepared from pea shell could be employed as an adsorbent for the removal of MB from aqueous solutions.

  3. Removal of acid blue 062 on aqueous solution using calcinated colemanite ore waste

    International Nuclear Information System (INIS)

    Colemanite ore waste (CW) has been employed as adsorbent for the removal of acid blue 062 anionic dye (AB 062) from aqueous solution. The adsorption of AB 062 onto CW was examined with respect to contact time, calcination temperature, particle size, pH, adsorbent dosage and temperature. The physical and chemical properties of the CW, such as particle sizes and calcinations temperature, play important roles in dye adsorption. The dye adsorption largely depends on the initial pH of the solution with maximum uptake occurring at pH 1.Three simplified kinetics models, namely, pseudo-first order, pseudo-second order, and intraparticle diffusion models were tested to investigate the adsorption mechanisms. The kinetic adsorption of AB 062 on CW follows a pseudo-second order equation. The adsorption data have been analyzed using Langmuir and Freundlich isotherms. The results indicate that the Langmuir model provides the best correlation of the experimental data. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of the adsorption of dye onto CW

  4. Removal of methylene blue from aqueous solution by wood millet carbon optimization using response surface methodology

    Science.gov (United States)

    Ghaedi, Mehrorang; Kokhdan, Syamak Nasiri

    2015-02-01

    The use of cheep, non-toxic, safe and easily available adsorbent are efficient and recommended material and alternative to the current expensive substance for pollutant removal from wastewater. The activated carbon prepared from wood waste of local tree (millet) extensively was applied for quantitative removal of methylene blue (MB), while simply. It was used to re-used after heating and washing with alkaline solution of ethanol. This new adsorbent was characterized by using BET surface area measurement, FT-IR, pH determination at zero point of charge (pHZPC) and Boehm titration method. Response surface methodology (RSM) by at least the number of experiments main and interaction of experimental conditions such as pH of solution, contact time, initial dye concentration and adsorbent dosage was optimized and set as pH 7, contact time 18 min, initial dye concentration 20 ppm and 0.2 g of adsorbent. It was found that variable such as pH and amount of adsorbent as solely or combination effects seriously affect the removal percentage. The fitting experimental data with conventional models reveal the applicability of isotherm models Langmuir model for their well presentation and description and Kinetic real rate of adsorption at most conditions efficiently can be represented pseudo-second order, and intra-particle diffusion. It novel material is good candidate for removal of huge amount of MB (20 ppm) in short time (18 min) by consumption of small amount (0.2 g).

  5. Adsorption of a textile dye 'Indanthrene Blue RS (C.I. Vat Blue 4)' from aqueous solutions onto smectite-rich clayey rock

    International Nuclear Information System (INIS)

    The adsorption of a textile dye, namely, Indanthrene Blue RS (C.I. Vat Blue 4) onto smectite-rich clayey rock (AYD) and its sulphuric acid-activated products (AYDS) in aqueous solution was studied in a batch system with respect to contact time, pH, and temperature. The adsorbents employed were characterized by X-ray diffraction, infrared spectroscopy and specific surface area, cation exchange capacity and point of zero charge were also estimated. The effect of contact time on dye adsorption showed that the equilibrium was reached after a contact time of 40 min for the both adsorbents. The optimum pH for dye retention was found 6.0 for AYDS and 7.3 for AYD. The equilibrium adsorption data were analysed using the Langmuir and Freundlich isotherms. The adsorption capacities (Qm) for AYD and AYDS were found 13.92 mg/g and 17.85 mg/g, respectively. The effect of temperature on the adsorption was also investigated; adsorption of Indanthrene Blue RS is an endothermic process. This study demonstrates that all the considered adsorbents can be used as an alternative emerging technology for water treatment.

  6. Adsorption of a textile dye 'Indanthrene Blue RS (C.I. Vat Blue 4)' from aqueous solutions onto smectite-rich clayey rock

    Energy Technology Data Exchange (ETDEWEB)

    Chaari, Islem, E-mail: chaari_islem@yahoo.fr [Laboratoire de Georessources, CERTE BP 95, 2050 Hamam-Lif (Tunisia); Feki, Mongi [Unite de chimie industrielle I, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia); Medhioub, Mounir [Departement des Sciences de la Terre, Faculte des Sciences de Sfax, 3018 Sfax (Tunisia); Bouzid, Jalel [Laboratoire Eau Energie et Environnement, departement de genie geologique, Ecole Nationale d' Ingenieurs de Sfax, BP W 3038 Sfax (Tunisia); Fakhfakh, Emna; Jamoussi, Fakher [Laboratoire de Georessources, CERTE BP 95, 2050 Hamam-Lif (Tunisia)

    2009-12-30

    The adsorption of a textile dye, namely, Indanthrene Blue RS (C.I. Vat Blue 4) onto smectite-rich clayey rock (AYD) and its sulphuric acid-activated products (AYDS) in aqueous solution was studied in a batch system with respect to contact time, pH, and temperature. The adsorbents employed were characterized by X-ray diffraction, infrared spectroscopy and specific surface area, cation exchange capacity and point of zero charge were also estimated. The effect of contact time on dye adsorption showed that the equilibrium was reached after a contact time of 40 min for the both adsorbents. The optimum pH for dye retention was found 6.0 for AYDS and 7.3 for AYD. The equilibrium adsorption data were analysed using the Langmuir and Freundlich isotherms. The adsorption capacities (Q{sub m}) for AYD and AYDS were found 13.92 mg/g and 17.85 mg/g, respectively. The effect of temperature on the adsorption was also investigated; adsorption of Indanthrene Blue RS is an endothermic process. This study demonstrates that all the considered adsorbents can be used as an alternative emerging technology for water treatment.

  7. The Application of Low-Cost Adsorbent for Reactive Blue 19 Dye Removal from Aqueous Solution: Lemna Minor

    OpenAIRE

    Davoud Balarak; Yousef Mahdavi; Ali Joghataei

    2015-01-01

    Background & Aims of the Study: Due to widespread use and adverse effect of dyes, the removal of dyes from effluents is necessary. This study was aimed to remove the reactive blue 19 dye removal from aqueous solution by dried Lemna minor. Materials and Methods:  The effect of various parameters including contact time, solution pH, adsorbent dosage and dye concentration was investigated in this experimental-lab study, Also, the isotherm and kinetic studies was performed for RB19 dy...

  8. Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars

    Science.gov (United States)

    Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

    2016-01-01

    Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB. PMID:27144922

  9. Adsorption behavior of a textile dye of Reactive Blue 19 from aqueous solutions onto modified bentonite

    International Nuclear Information System (INIS)

    The aim of this study is to evaluate adsorption kinetics, isotherms and thermodynamic parameters of Reactive Blue 19 (RB19) onto modified bentonite from aqueous solutions. The effects of pH, contact time, initial dye concentration and temperature were investigated in the experimentally. Natural bentonite was modified by using 1,6-diamino hexane (DAH) as a modifying agent. The characterization of modified bentonite (DAH-bentonite) was accomplished by using FTIR, TGA, BET and elemental analysis techniques. The optimum pH value for the adsorption experiments was found to be 1.5 and all the experiments were carried out at this pH value. The pseudo-second-order kinetic model agrees very well with the experimental results. Equilibrium data were also fitted well to the Langmuir isotherm model in the studied concentration range of RB19 at 20 deg. C. The results indicate that DAH-modified bentonite is a suitable adsorbent for the adsorption of textile dyes.

  10. Studies on Biosorption of Methylene Blue from Aqueous Solutions by Powdered Palm Tree Flower (Borassus flabellifer

    Directory of Open Access Journals (Sweden)

    M. Srinivas Kini

    2014-01-01

    Full Text Available Biosorption experiments were carried out for the removal of methylene blue (MB using palm tree male flower (PTMF as the biosorbent at various pH, temperature, biosorbent, and adsorbate concentration. The optimum pH was found to be 6.0. The kinetic data were fitted in pseudofirst-order and second-order models. The equilibrium data were well-fitted in Langmuir isotherm and the maximum equilibrium capacities of the biosorbent were found to be 143.6, 153,9, 157.3 mg/g at 303, 313, and 323 K, respectively. Thermodynamic data for the adsorption system indicated spontaneous and endothermic process. The enthalpy and entropy values for adsorption were obtained as 15.06 KJ/mol and 0.129 KJ/mol K, respectively, in the temperature range of 303–323 K. A mathematical model for MB transported by molecular diffusion from the bulk of the solution to the surface of PTMF was derived and the values of liquid phase diffusivity and external mass transfer coefficient were estimated.

  11. Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars.

    Science.gov (United States)

    Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

    2016-01-01

    Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB. PMID:27144922

  12. Catalytic thermolysis in treating Cibacron Blue in aqueous solution: Kinetics and degradation pathway.

    Science.gov (United States)

    Su, Claire Xin-Hui; Teng, Tjoon-Tow; Wong, Yee-Shian; Morad, Norhashimah; Rafatullah, Mohd

    2016-03-01

    A thermal degradation pathway of the decolourisation of Reactive Cibacron Blue F3GA (RCB) in aqueous solution through catalytic thermolysis is established. Catalytic thermolysis is suitable for the removal of dyes from wastewater as it breaks down the complex dye molecules instead of only transferring them into another phase. RCB is a reactive dye that consists of three main groups, namely anthraquinone, benzene and triazine groups. Through catalytic thermolysis, the bonds that hold the three groups together were effectively broken and at the same time, the complex molecules degraded to form simple molecules of lower molecular weight. The degradation pathway and products were characterized and determined through UV-Vis, FT-IR and GCMS analysis. RCB dye molecule was successfully broken down into simpler molecules, namely, benzene derivatives, amines and triazine. The addition of copper sulphate, CuSO4, as a catalyst, hastens the thermal degradation of RCB by aiding in the breakdown of large, complex molecules. At pH 2 and catalyst mass loading of 5 g/L, an optimum colour removal of 66.14% was observed. The degradation rate of RCB is well explained by first order kinetics model. PMID:26741557

  13. Electrode erosion during submerged arc treatment of methylene blue water solution

    International Nuclear Information System (INIS)

    Low voltage, low energy submerged pulsed arcs with a pulse repetition rate of 100 Hz, energy of 48 mJ and duration of 20 μs were used to determine the electrode erosion rate during treatment of 10 mg l−1 methylene blue (MB) dissolved in 40 ml of deionized water, with and without the addition of 0.5% H2O2. Anode/cathode pairs of Fe/Fe, Ti/Ti, Cu/Cu, Cu/Fe, Fe/Cu, Ti/Fe, Fe/Ti, Cu/Ti and Ti/Cu were used. Smaller cathode erosion was measured, in the solutions without H2O2, with copper cathodes than with other cathodes. Smaller anode erosion in the same conditions was demonstrated by using pairs with a Ti anode than with other anodes and larger erosion was found for Cu anodes. By adding H2O2 to the treated solution, smaller cathode erosion was measured by using pairs with a Ti cathode than with other cathodes and larger rates were measured for Fe cathodes. The largest anode erosion was observed for a Cu anode. The erosion of the anode and cathode depends on material combination of the electrode pairs, i.e. on the thermo physical properties of the electrode materials. The correlations of anode/cathode erosion ratio (Ga/Gc) with ratio (qam/qcm) for various electrode materials were found, where qam and qcm are heat fluxes in the body of the anode and cathode, respectively. The experimental data were fitted by curves described with equation Ga/Gc =A(qa/qc)−b where A and b are experimental constants. (paper)

  14. Removal of blue 1 dye of aqueous solutions with a modified clay with iron chloride

    International Nuclear Information System (INIS)

    At the present time, several technologies have been proposed to remove dyes from water, adsorption is one of the most feasible methods and adsorbents with different properties, such as activated carbon, zeolites, clays and hydrogels among others. In this work, the sorption behavior of blue 1 dye by a natural clay from a site located in the Center-East of Mexico, and other modified with iron chloride were determined. The materials were characterized by X-ray diffraction to analyze its crystal structure, by scanning electron microscopy and elemental microanalysis of energy dispersive X-ray spectrometry to determine the composition and morphology, and the zero point charges were also determined to know the charge distribution on the surface of the clay. The ph effect, contact time, dye concentration and temperature were the parameters considered in this study. The results showed that clay does not suffer any important changes in its structure after the chemical treatments (modification with ferric chloride and contact with blue 1 solutions). The ph influences lightly the adsorption of the dye with natural clay, but the same effect is not observed in the ferric modified clay among the factor ph 6 and 8. The equilibrium time and the sorption capacity for natural clay were 48 hours and 6.16 mg/g, while for the ferric clay were 24 hours and 14.22 mg/g. Adsorption kinetics results were best adjusted to the pseudo first and pseudo second order models. Adsorption isotherms were best adjusted to the Langmuir model, indicating that both clays have a homogeneous surface. Thermodynamic parameters (E, ΔS and ΔG and ΔH) were calculated for the dye adsorption by the natural clay using data of the adsorption kinetics at temperatures between 20 and 50 C, indicating that the adsorption process is exothermic. For the case of ferric clay, it was not possible to calculate these thermodynamic parameters because the adsorption capacities were similar in the range of selected

  15. Removal of blue indigo and cadmium present in aqueous solutions using a modified zeolitic material and an activated carbonaceous material

    International Nuclear Information System (INIS)

    In the last years the use of water has been increased substantially, it has been also altered its quality as a result of human activities such as mining, industrial activities and others. Water pollution caused by dyes and heavy metals has adverse effects on the environment, since both pollutants are very persisten even after conventional treatments. Denim blue and cadmium are not biodegradable. There is a growing interest in finding new, efficient and low cost alternative materials to remove such pollutants from the aqueous medium. The purpose of this work was to evaluate a modified zeolitic tuff and an activated carbonaceous material obtained from the pyrolysis of sewage sludge for the removal of denim blue and cadmium. The zeolitic material was modified with Na+ and Fe3+ solutions to improve its sorption properties for the removal of cadmium and denim blue, respectively. Carbonaceous material was treated with 10% HCl solution to remove ashes. Both materials were characterized by scanning electron microscopy and elemental analysis (EDS), specific surface areas (Bet), thermogravimetric analysis, infrared spectroscopy and X-ray diffraction. Simultaneously, the denim blue dye was characterized by infrared spectroscopy and its pKa value was determined, these data allowed the determination of its chemical properties and its acid-base behavior in solution. In the content of this work the term indigo blue was changed by denim blue, as it corresponds to the commercial name of the dye. To assess the sorption capacity of sorbents, the sorption kinetics and sorption isotherms in batch system were determined; the results were fitted to mathematical models such as the pseudo-first order, pseudo second order and second order to describe the sorption kinetics and the Langmuir, Freundlich and Langmuir-Freundlich isotherms to describe sorption processes. The results show that the most efficient material to remove denim blue from aqueous solutions is the carbonaceous material, and

  16. Red and blue LED weak light irradiation maintaining quality of cherry tomatoes during cold storage%LED红蓝弱光照射保持樱桃番茄冷库贮藏品质

    Institute of Scientific and Technical Information of China (English)

    雷静; 张娜; 阎瑞香; 许立兴; 李莹; 关文强

    2016-01-01

    Tomatoes are rich in compounds including carotenoids, vitamin C (Vc), and flavonoids, which are believed to be beneficial to human health. The increasing growth in the consumption of fresh cherry tomato (Lycopersicon esculentum Mill.) has driven the demand for developing new green postharvest technology to maintain the quality during cherry tomato’s storage period and shelf life. Blue and red lights among visible light regions may be still useful for the photosynthesis of some fresh products that are not fully mature during storage. Light-emitting diodes (LEDs) technologies could provide some opportunities to develop new equipment and method for controlling postharvest quality of cherry tomato treated by different light sources during storage and shelf life. Mature-green (breaker-stage) tomatoes were harvested and treated continuously with red and blue LED weak light at 4℃ for up to 20 d. Untreated tomatoes (the control) were kept in the dark for the same period. The effects of the treatments on the sensory quality (levels of appearance, color, odor and decay), Vc, reducing sugar, total soluble sugar, total soluble solids, titratable acid and lycopene were evaluated throughout the storage. The results showed that LED irradiation apparatus used in the experiment was stable and reliable. LED red and blue lamps could emit the designated light spectrum and not drift as the change of light intensity. The sensory quality was maintained at high level in all treatment during early storage period. After 10 d storage, the cherry tomatoes irradiated by LED red and blue light began to change color to yellow and red and had significantly better sensory quality than the control treatment (P<0.05), and LED red light had better effect than LED blue light. On the 20th day, the cherry tomatoes in the control showed inferior sensory quality involving flesh severe softening, apparent browning pitting on the peel and fungal decay spot, while the tomatoes irradiated by LED red and

  17. LED蓝光灯治疗新生儿高胆红素血症中的效果研究%Study on the Effect of LED Blue Light Treatment of Neonatal Hyperbilirubinemia

    Institute of Scientific and Technical Information of China (English)

    葛方英

    2013-01-01

    目的探讨LED蓝光灯(冷光源)在新生儿高胆红素血症治疗中的作用。方法选择120例新生儿高胆红素血症患儿,将其随机分为观察组(LED蓝光灯治疗)和对照组(传统的普通蓝光灯治疗),各80例。两组患儿均根据病情行兰光治疗每天照射16h,连续照射3d后,行挠动脉采血复查血清总胆红素及观察光疗后副作用。结果观察组光疗效果优于对照组,不良反应低于对照组。光疗后两组血清总胆红素与间接胆红素值下降显著,且观察组下降幅度大于对照组(P<0.01),光疗副作用观察组少于对照组。结论观察组的光照疗法效果好,安全性高,优于对照组。 LED 蓝光灯与蓝光箱比较,具有疗效好、方便、舒适、副作用少等优点.%Objective To investigate the LED blue light (cold light) in the treatment of neonatal hyperbilirubinemia role. Methods 120 cases of neonatal hyperbilirubinemia, which were randomly divided into observation group (LED blue light treatment) and control group (common blue light treatment of traditional), each of 80 cases. Two groups of children were given to the patients according the blue light treatment every 3 days after irradiation with 16h, l continuous irradiation, row radial artery blood review of serum total bilirubin and side ef ects observed after phototherapy. Results the ef icacy of phototherapy: observation group than the control group, the adverse reaction is lower than the control group. After the two groups of serum total bilirubin phototherapy and indirect bilirubin decreased significantly, and the observation group decreased than that of control group (P<0.01 group). To observe the light side ef ects than control group. Conclusion the group of light therapy has good ef ect, high safety, bet er than the control group. LED blue light compared with the blue box, has good curative ef ect, convenient, comfortable, less side ef ect.

  18. Photocatalytic degradation of methylene blue in water solution by multilayer TiO2 coating on HDPE

    International Nuclear Information System (INIS)

    A multilayer photocatalytic TiO2 coating on a high-density polyethylene (HDPE) disk was found to degrade aqueous methylene blue in a batch reactor study. The TiO2 coating was fabricated by a low-temperature method using polyurethane resin (PU) as a barrier layer for HDPE and as a binding agent for two TiO2 layers. Adequate adhesion between the HDPE substrate and PU barrier in aqueous environment was ensured with an oxygen plasma treatment. The photocatalytic effect of immersed TiO2 coating on the degradation of methylene blue in aqueous solution was monitored by UV-vis spectrometry as a function of UV-illumination time. Samples were allowed to adsorb methylene blue in the dark for 1 h before the UV-degradation experiments were started. The percentages of methylene blue degraded during 6 h UV illumination (λ = 365 nm) varied from 80% to 92%. The degradation followed pseudo-first order reaction kinetics, and the observed rate constants (kobs) were between 0.27 and 0.43 h-1.

  19. Adsorption studies of Methylene blue dye from aqueous solution onto phaseolus aureus biomaterials.

    Directory of Open Access Journals (Sweden)

    D. B. Jirekar

    2014-09-01

    Full Text Available Experimental investigation was carried out by using commercially available husk of green gram (phaseolusaureus seed to removal ofmethylene blue from aqueous medium. Husk of green gram seed was characterized by performing particle size distribution. The effect of contact time, effect of initial concentration of dye, effect of dosage, effect of salt, effect of pH, zero point pH and effect of temperature were studied in batch technique. Adsorption kinetic was verified by pseudo-first-order and pseudo-second-order models. The rate of adsorption of methylene blue followed by pseudo-second-order model for the dye concentration studied in the present case. Adsorption of methylene blue on green gram (phaseolusaureus seed husk is also followed by Langmuir and Freundlich adsorption isotherm.

  20. Uniform Cu2Cl(OH)3 hierarchical microspheres: A novel adsorbent for methylene blue adsorptive removal from aqueous solution

    International Nuclear Information System (INIS)

    Using the solution phase method without any surfactants or templates, the hierarchical of Cu2Cl(OH)3 microspheres were synthesized by freeze drying. The size and surface area of the microspheres are ca. 1–2 µm and 76.61 m2 g−1, respectively. A possible formation mechanism is presented based on the experimental results. Methylene blue was chosen to investigate the adsorption capacity of the as-prepared adsorbent. The effects of various experimental parameters, such as pH, initial dye concentration, and contact time were investigated. The results showed that the dye removal increased with the increasing in the initial concentration of the dye and also increased in the amount of microspheres used and initial pH. Adsorption data fitted well with the Freundlich adsorption isotherm. The thermodynamic analysis presented the exothermic, spontaneous and more ordered arrangement process. The microspheres could be employed effective for removal of dyes from aqueous solution. - Graphical abstract: The single-crystalline hierarchical Cu2Cl(OH)3 spheres can be prepared for the first time by using a template-free process through freeze-drying. Meanwhile, the hierarchical spheres exhibited high adsorption capacity to methylene blue. Display Omitted - Highlights: • Cu2Cl(OH)3 microspheres were successfully synthesized through a freeze drying process. • A possible formation mechanism of hierarchical microspheres was presented. • The Cu2Cl(OH)3 microspheres have high methylene blue adsorption capacity. • Methylene blue adsorption is a spontaneous and exothermic process. • The adsorption mechanism of microspheres onto dye was proposed in detail

  1. The Radiolysis of Direct Solar Orange 2 G L and Basic Sandocryl Blue B-3 G Dyes in Aqueous Solutions

    International Nuclear Information System (INIS)

    The effect of de-aeration on the decoloration of direct Solar Orange 2 G L (S O) and basic Sandocryl. Blue G-3 G (S B) dyes in aqueous solutions with concentrations ranging from 1.25x10-4 to 5x10=4 mole/L was studied at different gamma doses and dose rated. De-aerating the dye solutions by nitrogen bubbling to saturation promoted the decoloration of both dye solutions irradiated at different irradiation conditions. The decoloration rate constant K4(mole/L s) for the dyes increases with the increase of dose rate from 0.44 to 2.22 Gy/s and de-aeration treatment. The contribution of dose rate for decoloration is higher than that to de-aeration. Increase in irradiation dose was found to increase the degree of decoloration of dye solutions. The degree of decoloration was found to decrease with increasing the initial dye concentration. The absorbed dose 0.792 kGy, depending on the initial dye concentration, resulted in partial decoloration of dye solutions while the dose 4.0 kGy decolored the aqueous solutions of both dyes at faster rates. The radiation chemical yield for decoloration Gd was found to increase with de-aeration, the increase of initial dye concentration and decreases with the increase of dose. An attempt to explain the decoloration of the dye solutions based on the product species resulting from water radiolysis is given

  2. Adsorption of Methylene Blue from Aqueous Solution onto a Low-Cost Natural Jordanian Tripoli

    OpenAIRE

    Atef S. ALzaydien

    2009-01-01

    Background: Dyes and pigments are widely used, mostly in the textiles, paper, plastics, leather, food and cosmetic industry to color products. The release of colored wastewater from these industries may present an eco-toxic hazard. Various techniques like precipitation, ion exchange, chemical oxidation, and adsorption have been used for the removal of toxic pollutant from, wastewater. Methylene blue (MB) is selected as a model compound for evaluating the potential of tripoli to remove dye fro...

  3. Synthesis and highly visible-induced photocatalytic activity of CNT-CdSe composite for methylene blue solution

    Directory of Open Access Journals (Sweden)

    Chen Ming-Liang

    2011-01-01

    Full Text Available Abstract Carbon nanotube-cadmium selenide (CNT-CdSe composite was synthesized by a facile hydrothermal method derived from multi-walled carbon nanotubes as a stating material. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy (TEM, and UV-vis diffuse reflectance spectrophotometer. The as-synthesized CNT-CdSe composite efficiently catalyzed the photodegradation of methylene blue in aqueous solutions under visible-light irradiation, exhibiting higher photocatalytic activity.

  4. Comparison between the behavior of dosimeters FAM and FAT after irradiation with LED; Comparacao entre o comportamento dos dosimetros FAM e FAT apos irradiacao com LED

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, M.G.O.; Lima, V.L.; Nascimento, R.K.; Souza, V.L.B., E-mail: vlsouza@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil). Divisao de Laboratorios Tecnico-Cientifico

    2013-08-15

    The work consists in evaluating the photosensitivity of Fricke solution modified by addition of dyes acting as a photosensitizers, comparing the behavior of FAM dosimeters (Fricke solution modified by addition of methylene blue) and FAT (Fricke solution modified by addition of toluidine blue) after irradiation with LED in acrylic phantom. An arrangement of LED, prepared for this purpose and a set of commercially available LED were used for irradiation the samples, as well as an acrylic phantom. The results show that the FAM is more sensitive dosimeter than FAT; samples irradiated with LED demonstrated the sensitivity of the dosimeters to red and blue light obtaining calibration curves with good correlation coefficients, so that these dosimeters may be used in the future for photodynamic therapy dosimetry. (author)

  5. Evaluation of Electro-Fenton Process Performance for COD and Reactive Blue 19 Removal from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Mohammad Malakootian

    2013-02-01

    Full Text Available Background and Objectives: Synthetic dyes represent one of the largest groups of pollutants in wastewater of dying industries. Discharging these wastewaters into receiving streams not only affects the aesthetic but also reduces photosynthetic activity. Electrochemical advanced oxidation processes such as Electro-Fenton process are low operational and have high mineralization degree of pollutants. In this study, we investigated affective factors in this process to determine the optimum conditions for dye and COD removal from aqueous solutions containing Reactive Blue 19 dye.Materials and Methods: Synthetic samples containing Reactive Blue 19 dye were prepared by dissolving dye powder in double distilled water. and the the solution prepared was transferred into pilot electrochemical cell having two anode and cathode electrode made of iron and carbon. Electro-Fenton process was began by adding of Fe2+ ions and establishing electrical potential difference. After testing and at specified time intervals, each sample was collected from the pilot cell, and process performance was evaluated through measuring dye concentration and COD. Results: Based on the results obtained, optimum conditions of Electro-Fenton process for dye and COD removal was determined. Accordingly, potential difference of 20 volt for dye concentration up to 100 mg/L and potential difference of 30 volt for dye concentration of more than 200 mg/L, reaction time 60 minutes, 0.5 mg/L of Fe2+ concentration and suitable pH for the maximum dye removal efficiency equaled 4 respectively. Under such conditions, the dye and COD removal was 100 and 95% respectively.Conclusion: Based on the results obtained, it was revealed that Electro-Fenton process has significant ability in not only dye removal but also in COD removal. Accordingly, it was found that the effective parameters in Electro-Fenton process for removal Reactive Blue19 dye are electric potential difference, concentration of iron ions

  6. TiO2 and N-Doped TiO2 Induced Photocatalytic Inactivation of Staphylococcus aureus under 405 nm LED Blue Light Irradiation

    Directory of Open Access Journals (Sweden)

    Hongfei Chen

    2012-01-01

    Full Text Available Irradiation source has been a serious impediment to induce photocatalytic bacterial inactivation which was taken as an advanced indoor air purification technique. Here we reported the synergistic effects of 405 nm LED light and TiO2 photocatalyst in inactivation process of Staphylococcus aureus (S. aureus. In this work, TiO2 and N-doped TiO2 particles were, respectively, suspended into the nutrient broth suspension with S. aureus. Then, the mixed system was exposed to a 405 nm LED light source with energy density of about 0.2 W/cm2 for 3 hours. Irradiated suspension was then scanned by UV-vis spectrophotometer for bacteria survive/death rate statistics. Subsequently, the inactivation efficiency was calculated based on the difference of the absorption optical density between experimental and controlled suspensions. Results showed that both TiO2 and N-doped TiO2 particles exhibit potential bacterial inactivation effects under similar experimental conditions. Specifically, N-doped TiO2 with the concentration of 5 g/L displayed enhanced inactivation efficiency against S. aureus under 405 nm LED light irradiation. Thus, it is a promising indoor air purification technique by using N-doped TiO2 particles under the LED light irradiation.

  7. Triazolyl blue tetrazolium bromide as a novel corrosion inhibitor for steel in HCl and H2SO4 solutions

    International Nuclear Information System (INIS)

    Research highlights: → Triazolyl blue tetrazolium bromide (TBTB) is found to be a novel good inhibitor for the corrosion of CRS in 1.0 M HCl and 0.5 M H2SO4 solutions. → The comparison of inhibition performance in HCl and that in H2SO4 are discussed in detail. → The corrosion inhibition is satisfactorily discussed by adsorption mode and thermodynamic parameter. → The electrochemical inhibitive mechanism is explained by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) results. → The adsorption of TBTB is presented. - Abstract: The inhibition effect of triazolyl blue tetrazolium bromide (TBTB) on the corrosion of cold rolled steel (CRS) in 1.0 M HCl and 0.5 M H2SO4 solution was investigated for the first time by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that TBTB is a very good inhibitor, and is more efficiency in 1.0 M HCl than 0.5 M H2SO4. The adsorption of TBTB on CRS surface obeys Langmuir adsorption isotherm. Polarization curves reveal that TBTB acts as a mixed-type inhibitor in both acids.

  8. Postpartum Blues

    Medline Plus

    Full Text Available ... baby blues). What are the baby blues? The word "blues" is not really correct since women with ... baby blues). What are the baby blues? The word "blues" is not really correct since women with ...

  9. Origin of blue photoluminescence from colloidal silicon nanocrystals fabricated by femtosecond laser ablation in solution.

    Science.gov (United States)

    Hao, H L; Wu, W S; Zhang, Y; Wu, L K; Shen, W Z

    2016-08-12

    We present a detailed investigation into the origin of blue emission from colloidal silicon (Si) nanocrystals (NCs) fabricated by femtosecond laser ablation of Si powder in 1-hexene. High resolution transmission electron microscopy and Raman spectroscopy observations confirm that Si NCs with average size 2.7 nm are produced and well dispersed in 1-hexene. Fourier transform infrared spectrum and x-ray photoelectron spectra have been employed to reveal the passivation of Si NCs surfaces with organic molecules. On the basis of the structural characterization, UV-visible absorption, temperature-dependent photoluminescence (PL), time-resolved PL, and PL excitation spectra investigations, we deduce that room-temperature blue luminescence from colloidal Si NCs originates from the following two processes: (i) under illumination, excitons first form within colloidal Si NCs by direct transition at the X or Γ (Γ25 → Γ'2) point; (ii) and then some trapped excitons migrate to the surfaces of colloidal Si NCs and further recombine via the surface states associated with the Si-C or Si-C-H2 bonds. PMID:27348227

  10. Effectiveness of Quercus Branti Activated Carbon in Removal of Methylene Blue from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Abdolmotaleb Seidmohammadi

    2015-10-01

    Full Text Available Background & Aims of the Study: Dyes are one of the most contaminants in textile industrial wastewater that they are often carcinogenic, mutagenic and non-degradable. Therefore, with regard to environmental aspects, their removal from effluents is very essential. The purpose of this study was the perception of adsorption process and promotion of an economic technology for colored wastewater treatment. Therefore, activated carbon from Oak fruit bark was used as an effective and economic adsorbent. Materials & Methods: This study was performed at laboratory scale and batch system. At present study, the adsorbent surface properties was evaluated by use of the (FT-IR test and scanning electronic microscope (SEM. Also, effect of various operating parameters such as pH, contact time, adsorbent dose, initial dye concentration and temperature on dye removal from synthetic wastewater were studied. Results: In this study, maximum removal efficiency of methylene blue were achieved at optimal pH=6, reaction time 180 minutes, and adsorbent dose 2 gl-1. Methylene blue removal efficiency with initial concentration of 100 mg.l-1 was 91.08%. Conclusions: According to results, it was cleared that : Quercus branti activated carbon can be used as an effective and economic adsorbent in waste water treatment processes.

  11. Tuberose sticks as an adsorbent in the removal of methylene blue from aqueous solution

    International Nuclear Information System (INIS)

    The use of low-cost and ecofriendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. Methylene Blue was used as model compound. The effects of contact time, initial dye concentration (20, 30, 40, 50 mg/L), pH and adsorbent dosages have been studied at 25 C. The equilibrium time was found to be 30 min for all the dye concentrations. A maximum removal of 80% was obtained at pH 11.0 for an adsorbent dose 50 mg/50 mL of 40 mg/L dye concentration. Adsorption increased with increase in pH. Maximum desorption of 50% was achieved in water medium at pH 2.0. (author)

  12. Removal of methylene blue from aqueous solution by dehydrated wheat bran carbon

    International Nuclear Information System (INIS)

    Dyes are usually presents in the effluent water of many industries, such as textiles, leather, paper, printing and cosmetics. The effectiveness of dye adsorption from wastewater has made to get alternative different low cost adsorbent to other expensive treatment methods. The adsorption of methylene blue onto dehydrated wheat bran (DWB) was investigated at temperatures (25-45 deg. C), initial methylene blue (MB) concentrations (100-500 mg L-1) and adsorbent dosage at the given contact time for the removal of dye. The optimum adsorption conditions were found to be as medium pH of 2.5 and at the temperature of 45 deg. C for the varying adsorbent dosage. Equilibrium isotherms were analysed by Freundlich, Langmuir and Redlich-Peterson isotherm equations using correlation coefficients. Adsorption data were well described by the Langmuir model, although they could be modelled by the Freundlich and Redlich-Peterson model as well. The pseudo-first order and pseudo-second order kinetic models were applied to test the experimental data. It was concluded that the pseudo-second order kinetic model provided better correlation of the experimental data rather than the pseudo-first order model. The mass transfer model as intraparticle diffusion was applied to the experimental data to examine the mechanisms of rate controlling step. It was found that at the higher initial MB concentration, intraparticle diffusion is becoming significant controlling step. The thermodynamic constants of the adsorption process were also evaluated by using the Langmuir constants related to the equilibrium of adsorption at temperatures varied in the range 25-55 deg. C

  13. 蓝光激发红色荧光粉的研究进展及其在白光LED中的应用%Research Progress and Applications of Blue Light Excited Red Phosphors for white LED

    Institute of Scientific and Technical Information of China (English)

    柏朝晖; 张希艳; 刘全生; 卢利平; 米晓云; 王晓春

    2011-01-01

    Blue light-emitting diodes (LEDs) chip excited yellow phosphor is the main way to achieve white LEDs. It is important to introduce red phosphor into yellow phosphor on the adjustment of the color index and color temperature of white LEDs. This paper emphatically presents and reviews the luminescent properties, latest research development and application on white LED of the broad band emission red phosphors of sulfide, nitride, aluminate phosphors excited by blue chips. Through contrast, it is found that nitride phosphor is the most promising type of red phosphor because it can be effectively excited from the near ultraviolet to green light, emits red fluorescence peaking form 600m to 650nm following various of the matrix composition and has excellent chemical stability, thermal stability. Two or more phosphors instead of single yellow phosphor are conductive to adjust the color temperature of white LED and to improve the color rendering index.%蓝光LED芯片激发黄色荧光粉是目前白光LED的主要实现方式,引入红色荧光粉对调整白光LED的显色指数及色温有重要意义.重点介绍和评述了可被蓝光激发且具有宽发射带的硫化物、氮化物、铝酸盐等几种体系红色荧光粉的发光性质、最新研究成果及在白光LED中的应用.对比发现,氮化物荧光粉可被从近紫外到可见绿光有效激发,随基质组成的不同,可发出峰值波长为600~650nm的红色荧光,且由于其优良的化学稳定性、热稳定性成为最有前途的一类红色荧光粉.采用两种以上的荧光粉代替单一黄色荧光粉,有利于调整白光LED的色温,提高显色指数.

  14. New Phosphors for White LEDs

    Institute of Scientific and Technical Information of China (English)

    LIU Ru-Shi

    2004-01-01

    White light-emitting diodes (WLEDs) have matched the emission efficiency of florescent lights and will rapidly spread as light source for homes and offices in the next 5 to 10 years. WLEDs provide a light element having a semiconductor light emitting layer (blue or UV LEDs) and photoluminescence phosphors. GaN-based highly efficient blue InGaN LEDs combined with phosphors can produce white light. These solid-state LED lamps have a number of advantages over conventional incandescent bulbs and halogen lamps, such as high efficiency to convert electrical energy into light, reliability, and long operating lifetime (about 100,000 hours). For the purpose of development of high energy-efficient white light sources, we need to produce highly efficient new phosphors, which can absorb excitation energy from blue or UV LEDs and generate emissions.In this paper, we investigate the development of blue or UV LEDs by the appropriate combination of new phosphors which can lead us to obtain high brightness white light. The criteria of choosing the best phosphors, for blue (380-450 nm) and UV (360-400 nm) LEDs, strongly depends on the absorption and emission of the phosphors. Moreover, the balance light between the light emission from blue LEDs and the yellow YAG:Ce,Gd phosphor is important to obtain white light with high color temperature. The phosphors with high efficiency which can be excited by UV LEDs are important to obtain the white light with high color rendering index.

  15. The TrueBlue study: Is practice nurse-led collaborative care effective in the management of depression for patients with heart disease or diabetes?

    Directory of Open Access Journals (Sweden)

    Coates Michael

    2009-06-01

    Full Text Available Abstract Background In the presence of type 2 diabetes (T2DM or coronary heart disease (CHD, depression is under diagnosed and under treated despite being associated with worse clinical outcomes. Our earlier pilot study demonstrated that it was feasible, acceptable and affordable for practice nurses to extend their role to include screening for and monitoring of depression alongside biological and lifestyle risk factors. The current study will compare the clinical outcomes of our model of practice nurse-led collaborative care with usual care for patients with depression and T2DM or CHD. Methods This is a cluster-randomised intervention trial. Eighteen general practices from regional and metropolitan areas agreed to join this study, and were allocated randomly to an intervention or control group. We aim to recruit 50 patients with co-morbid depression and diabetes or heart disease from each of these practices. In the intervention group, practice nurses (PNs will be trained for their enhanced roles in this nurse-led collaborative care study. Patients will be invited to attend a practice nurse consultation every 3 months prior to seeing their usual general practitioner. The PN will assess psychological, physiological and lifestyle parameters then work with the patient to set management goals. The outcome of this assessment will form the basis of a GP Management Plan document. In the control group, the patients will continue to receive their usual care for the first six months of the study before the PNs undergo the training and switch to the intervention protocol. The primary clinical outcome will be a reduction in the depression score. The study will also measure the impact on physiological measures, quality of life and on patient attitude to health care delivered by practice nurses. Conclusion The strength of this programme is that it provides a sustainable model of chronic disease management with monitoring and self-management assistance for

  16. Polymer-supported solution synthesis of blue luminescent BaMgAl10O17:Eu2+ particles

    International Nuclear Information System (INIS)

    A blue phosphor, europium doped barium magnesium aluminate (BaMgAl10O17:Eu2+) 200-300 nm in size, has been synthesized via a solution phase method using a mixture of metal hydroxide with metal chloride as the precursor source. A water-soluble polymer of high molecular weight was used in the synthesis process. The effects of polymer media and heating treatments on the physical and optical properties such as crystallinity and photoluminescence of particles were investigated. Activation of the luminescence center under a reducing atmosphere has been accomplished concurrently with crystal growth. Photoluminescent (PL) emission spectra of particles centered around 450 nm when using a 254 nm excitation wavelength. The polymer potentially prevents agglomeration and enhances the PL emission of the particles

  17. Combination treatment of moderate to severe acne with Xiaocuo facial mask and red-blue LED phototherapy%消痤面膜联合LED红蓝光照射治疗中重度痤疮疗效观察

    Institute of Scientific and Technical Information of China (English)

    张昆梅; 周宇晗; 汪春惠; 向光

    2013-01-01

    Objective:To study the clinical efficacy of Xiaocuo facial mask combined with red - blue LED phototherapy in the treatment of moderate to severe acne. Methods A total of 320 patients with moderate to severe acne (Pillsbury grade II to IV ) were divided into the treatment group (160 patients) and the control group (160 patients). Xiaocuo facial mask combined with red - blue LED phototherapy and drug were given to the treatment group while the control group was treated with drug alone. After 6 weeks, the therapeutic efficacy was analyzed following completion of the therapy. Results The effective rate was 83.48% in the treatment group (severe) , 51.40% in the control group (severe), 94.12% in the treatment group (moderate) and 73.58% in the control group (moderate) . The total effective rate of the control group was significantly higher than the control group (x2>6.63, P<0.01). conclusions The combined therapy of Xiaocuo facial mask and red- blue LED phototherapy is more effective than drug alone in the treatment of morderate to severe acne, and adverse reaction is slight.%目的:探讨消痤面膜联合LED红蓝光照射治疗中重度痤疮的临床疗效.方法:选择中重度(Pillsbur分级为Ⅱ至Ⅳ度)寻常性痤疮320例,随机分为治疗组(160例)和对照组(160例).治疗组在药物治疗的同时,采用消痤面膜联合LED红蓝光照射方法;对照组单用药物治疗,治疗6周后分析其治疗效果.结果:总体效果评价中,治疗组(重度)有效率83.48%,对照组(重度)有效率51.40%;治疗组(中度)有效率94.12%,对照组(中度)有效率73.58%.治疗组(中、重度)有效率均明显高于对照组,差异有统计学意义(x2 >6.63,P<0.01).结论:消痤面膜联合LED红蓝光照射治疗中重度痤疮疗效好,其疗效明显优于单用药物治疗,不良反应轻.

  18. 电子束辐照对GaN基蓝光LED性能的影响%Influence of Electron Beam Irradiation on GaN-Based Blue LED

    Institute of Scientific and Technical Information of China (English)

    梁亮; 牛萍娟; 于莉媛

    2010-01-01

    研究了低能电子束辐照(LEEBI)对大功率GaN基蓝光LED性能的影响.利用实验室提供的电子束模拟空间电子辐射,对蓝光LED进行LEEBI,并对比未辐照的LED,研究其电学性质和光学性质的变化.结果表明,在电子束辐照下,LED发光强度提高,正向电压变小,击穿电压变小.同时利用电子束辐照机理对实验结果进行了分析和讨论.

  19. Removal of methylene blue from aqueous solution with magnetite loaded multi-wall carbon nanotube: Kinetic, isotherm and mechanism analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ai, Lunhong, E-mail: ah_aihong@163.com [Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Shida Road 1, Nanchong 637002 (China); College of Chemistry and Chemical Engineering, China West Normal University, Shida Road 1, Nanchong 637002 (China); Zhang, Chunying [College of Chemistry and Chemical Engineering, China West Normal University, Shida Road 1, Nanchong 637002 (China); Liao, Fang; Wang, Yao [Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Shida Road 1, Nanchong 637002 (China); College of Chemistry and Chemical Engineering, China West Normal University, Shida Road 1, Nanchong 637002 (China); Li, Ming; Meng, Lanying [College of Chemistry and Chemical Engineering, China West Normal University, Shida Road 1, Nanchong 637002 (China); Jiang, Jing [Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Shida Road 1, Nanchong 637002 (China); College of Chemistry and Chemical Engineering, China West Normal University, Shida Road 1, Nanchong 637002 (China)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer M-MWCNTs were synthesized by a facile one-pot solvothermal method and used as an efficient adsorbent for removing toxic dye from aqueous solution. Black-Right-Pointing-Pointer The adsorption process was characterized by kinetics and isotherm analysis. Black-Right-Pointing-Pointer FTIR analysis was employed to investigate the interactions between M-MWCNTs and dye. - Abstract: In this study, we have demonstrated the efficient removal of cationic dye, methylene blue (MB), from aqueous solution with the one-pot solvothermal synthesized magnetite-loaded multi-walled carbon nanotubes (M-MWCNTs). The as-prepared M-MWCNTs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The effects of contact time, initial dye concentration, and solution pH on the adsorption of MB onto M-MWCNTs were systematically studied. It was shown that the MB adsorption was pH-dependent. Adsorption kinetics was best described by the pseudo-second-order model. Equilibrium data were well fitted to the Langmuir isotherm model, yielding maximum monolayer adsorption capacity of 48.06 mg g{sup -1}. FTIR analysis suggested that the adsorption mechanism was possibly attributed to the electrostatic attraction and {pi}-{pi} stacking interactions between MWCNTs and MB.

  20. The Application of Low-Cost Adsorbent for Reactive Blue 19 Dye Removal from Aqueous Solution: Lemna Minor

    Directory of Open Access Journals (Sweden)

    Davoud Balarak

    2015-10-01

    Full Text Available Background & Aims of the Study: Due to widespread use and adverse effect of dyes, the removal of dyes from effluents is necessary. This study was aimed to remove the reactive blue 19 dye removal from aqueous solution by dried Lemna minor. Materials and Methods:  The effect of various parameters including contact time, solution pH, adsorbent dosage and dye concentration was investigated in this experimental-lab study, Also, the isotherm and kinetic studies was performed for RB19 dye adsorption process. Results: The results indicated that RB19 dye removal efficiency increases by increasing of contact time and adsorbent dosage. The equilibrium time was 75 min ad the maximum dye removal efficiency was obtained in pH=3. Also, the dye removal efficiency decreases by increasing of pH and initial concentration. It was found that the equilibrium data was best follow by Langmuier isotherm. Also, the pseudo-second-kinetic model was best applicable for RB 19 dye adsorption. Conclusion: It can be concluded that the dried Lemna minor can be considered as an effective adsorbent to remove the RB19 dye.

  1. Evaluation of La-Doped Mesoporous Bioactive Glass as Adsorbent and Photocatalyst for Removal of Methylene Blue from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Liying Li

    2015-01-01

    Full Text Available A series of La-doped mesoporous bioactive glass (BG-La materials with excellent biosafety and hypotoxicity have been prepared and tested as adsorbent. The study was aimed to evaluate the possibility of utilizing BG-La for the adsorptive removal of methylene blue (MB from aqueous solution and test the adsorption and desorption behavior of this new material. The process parameters affecting adsorption behaviors such as pH, contact time, and initial concentration and the photocatalytic degradation of MB were systematically investigated. The result showed that BG-La had excellent removal rate (R of MB, and BG-La showed better photocatalytic effect than undoped mesoporous bioactive glass (BG. Furthermore, the MB loaded BG-La was easily desorbed with acid solution due to its electronegativity and mesoporous structure. The result indicated that these materials can be employed as candidates for removal of dye pollutant owing to their high removal rate, excellent photocatalytic effect, desorption performance, and their reusability.

  2. Different Techniques for Enhancing the Removal of Methylene Blue (MB)dye From Aqueous Solution

    International Nuclear Information System (INIS)

    Different techniques were conducted for removal of MB dye from aqueous solution. These techniques which were used separately are: (i) adsorption using activated carbon (AC) prepared from composite of different ratios of Date Pits-Clay (DP-C); (II) Chemical oxidation using H2O2; and (III) photo degradation using UV irradiation. In the adsorption technique, a series of experiments were undertaken in an agitated batch to assess the effect of the system variables; types of activated carbon, ph, adsorbent and adsorbate concentration, temperature and interfering ions. From the isotherm studies, the Langmuir monolayer capacity was 416.67 mg/g. The kinetic parameters have shown that they could be fitted well to the pseudo second- order kinetic and intra-particle diffusion models. The temperature study showed that the MB adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. The presence of interfering ions has an insignificant effect with the exception of Cl- anion that slightly decreases the adsorption of MB. Finally, the addition of H2O2 and UV irradiation in the presence AC enhances the removal of MB dye. The rates of the second order for the removal of MB dye take the following order: AC+H2O2+UV > AC+UV >AC+H2O2 > AC.

  3. Solution Structure of Reduced Plastocyanin from the Blue-Green Alga Anabaena Variabilis

    DEFF Research Database (Denmark)

    Led, J.J.; Badsberg, U.; Jørgensen, A.M.;

    1996-01-01

    The three-dimensional solution structure of plastocyanin from Anabaena variabilis (A.v. PCu) has been determined by nuclear magnetic resonance spectroscopy. Sixty structures were calculated by distance geometry from 1141 distance restraints and 46 dihedral angle restraints. The distance geometry...... structures were optimized by simulated annealing and restrained energy minimization. The average rms deviation from the mean structure for the 20 structures with the lowest total energy is 1.25 Angstrom for the backbone atoms and 1.75 Angstrom for all heavy atoms. Overall, the global tertiary fold of A. v...... turn is compensated for by an extension of the small helix [from Ala53(51) to Ser60(58) in A.v. PCu] found in other plastocyanins. Moreover, the extra residues of A.v. PCu from Pro77 to Asp79 form an appended loop. These two features allow A.v. PCu to retain almost the same global fold as observed in...

  4. Adsorption of Methylene Blue from Aqueous Solution onto a Low-Cost Natural Jordanian Tripoli

    Directory of Open Access Journals (Sweden)

    Atef S. ALzaydien

    2009-01-01

    Full Text Available Problem statement: It is well documented that lead is one of contaminants of industrial wastewaters and its pollution exists in the wastewater of many industries. As a result, recent research has focused on the development of cost effective alternatives using various natural sources and industrial wastes. In this setting, the use of low-cost agricultural materials, waste and residues for recovering heavy metals from contaminated industrial effluent has emerged as a potential alternative method to high cost adsorbents. In the present study, adsorption of lead(II ions onto Orange Peel (OP, a typical agricultural byproduct, was investigated systematically with the variation in the parameters of pH, sorbent dosage, contact time and the initial concentration of adsorbate. Langmuir and Freundlich isotherms were used to analyze the equilibrium data. Kinetic and thermodynamic parameters were also calculated to describe the adsorption mechanism. Approach: The Orange Peel (OP was obtained from a local market in the south of Jordan. The orange peel was cut into small pieces using scissors. Then OP was dried at 100°C for 24 h using hot air oven. Qualitative analyses of the main functional groups involved in metal adsorption were performed using a Fourier transformed infrared spectrometer (Perkin-Elmer FTIR 1605, ¨Uberlingen, Germany. Biosorption experiments were carried out in a thermostatic shaker at 180 rpm and at an ambient temperature (20±2°C using 250 mL shaking flasks containing 100 mL of different concentrations and initial pH values of Pb(II solutions, prepared from reagent grade salt Pb(NO32 (Merck. The initial pH values of the solutions were previously adjusted with 0.1 M HNO3 or NaOH and measured using a hand held pH meters (315i/SET. The sorbent (0.2-1.0 g was added to each flask and then the flasks were sealed up to prevent change of volume of the solution during the experiments. After shaking the flasks for

  5. Solution structure of reduced plastocyanin from the blue-green alga Anabaena variabilis

    DEFF Research Database (Denmark)

    Badsberg, U; Jørgensen, A.M.; Gesmar, H;

    1996-01-01

    The three-dimensional solution structure of plastocyanin from Anabaena variabilis (A.v.PCu) has been determined by nuclear magnetic resonance spectroscopy. Sixty structures were calculated by distance geometry from 1141 distance restraints and 46 dihedral angle restraints. The distance geometry...... structures were optimized by simulated annealing and restrained energy minimization. The average rms deviation from the mean structure for the 20 structures with the lowest total energy is 1.25 A for the backbone atoms and 1.75 A for all heavy atoms. Overall, the global tertiary fold of A.v.PCu resembles...... extension of the small helix [from Ala53(51) to Ser60(58) in A.v.PCu] found in other plastocyanins. Moreover, the extra residues of A.v.PCu from Pro77 to Asp79 form an appended loop. These two features allow A.v.PCu to retain almost the same global fold as observed in other plastocyanins. From a comparison...

  6. A Novel Biosorbent, Water-Hyacinth, Uptaking Methylene Blue from Aqueous Solution: Kinetics and Equilibrium Studies

    Directory of Open Access Journals (Sweden)

    Md. Nasir Uddin

    2014-01-01

    Full Text Available The adsorption of MB dye from aqueous solution onto HCl acid treated water-hyacinth (H-WH was investigated by carried out batch sorption experiments. The effect of process parameters such as pH, adsorbent dosage, concentrations and contact time, and ionic strength were studied. Adsorption of MB onto H-WH was found highly pH dependent and ionic strength shows negative impact on MB removal. To predict the biosorption isotherms and to determine the characteristic parameters for process design, Langmuir, Freundlich, Temkin, and Halsey isotherms models were utilized to equilibrium data. The adsorption kinetics was tested for pseudo-first-order (PFO, pseudo-second-order (PSO, intraparticle diffusion (IPD, and Bangham’s kinetic models. The Langmuir isotherm model showed the goodness-of-fit among the tested models for equilibrium adsorption of MB over H-WH and indicated the maximum adsorption capacity as 63.30 mg/g. Higher coefficient of determination (R2>0.99 and better agreement between the qe (experimental and qe (calculated values predicted that PSO kinetic model showed the goodness-of-fit for kinetic data along with rate constant 1.66×10-3, 4.42×10-3, and 3.57×10-3 mg·g-1min⁡-1/2⁡, respectively, for the studied concentration range. At the initial stage of adsorption, the overall rate of dye uptake was found to be dominated by external mass transfer, and afterwards, it is controlled by IPD mechanism.

  7. Adsorption of Procion Blue MX-R dye from aqueous solutions by lignin chemically modified with aluminium and manganese.

    Science.gov (United States)

    Adebayo, Matthew A; Prola, Lizie D T; Lima, Eder C; Puchana-Rosero, M J; Cataluña, Renato; Saucier, Caroline; Umpierres, Cibele S; Vaghetti, Julio C P; da Silva, Leandro G; Ruggiero, Reinaldo

    2014-03-15

    A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al(3+) (CML-Al) and Mn(2+) (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pHPZC. The established optimum pH and contact time were 2.0 and 5h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16mgg(-1) at 298K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone+50% of 0.05molL(-1) NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents. PMID:24462989

  8. Removal of methylene blue from aqueous solutions by an adsorbent based on metal-organic framework and polyoxometalate

    International Nuclear Information System (INIS)

    A metal-organic framework (Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate) composite based on polyoxometalate (H6P2W18O62) was synthesized by a simple one-pot solvent-thermal method and applied as an adsorbent to remove methylene blue (MB) from aqueous solution. The chemical structure, morphology and thermostability of the composite were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TG) and N2 adsorption–desorption isotherms. The removal rate of the composite H6P2W18O62@Cu3(BTC)2 was greater than that of the pure Cu3(BTC)2, especially at higher initial concentrations, showing that the adsorption performance of porous Cu3(BTC)2 can be improved through the modification of H6P2W18O62. The effect factors containing the initial concentration, contact time, initial solution pH and temperature of MB adsorption onto the composite were systematically explored. The experimental isotherm data was found to fit the Freundlich model well and the process of MB adsorption onto H6P2W18O62@Cu3(BTC)2 was controlled by the pseudo-second-order kinetic model. The thermodynamic parameters illustrated that the adsorption was spontaneous and exothermic process. These results show that designing a metal-organic framework composite is a quite promising strategy to achieve extreme application for metal-organic framework. - Graphical abstract: Comparison of removal rate for MB in pure Cu3(BTC)2 and H6P2W18O62@Cu3(BTC)2 at different initial concentration. - Highlights: • Metal-organic framework (MOF) composite in the adsorption application was proposed. • The adsorption rate of MOF was improved by introducing polyoxometalates. • The adsorption isotherm and kinetic was used to describe the adsorption mechanism. • The thermodynamic parameters on the composite were thoroughly investigated

  9. Blue gods, blue oil, and blue people.

    Science.gov (United States)

    Fairbanks, V F

    1994-09-01

    Studies of the composition of coal tar, which began in Prussia in 1834, profoundly affected the economies of Germany, Great Britain, India, and the rest of the world, as well as medicine and surgery. Such effects include the collapse of the profits of the British indigo monopoly, the growth in economic power of Germany based on coal tar chemistry, and an economic crisis in India that led to more humane tax laws and, ultimately, the independence of India and the end of the British Empire. Additional consequences were the development of antiseptic surgery and the synthesis of a wide variety of useful drugs that have eradicated infections and alleviated pain. Many of these drugs, particularly the commonly used analgesics, sulfonamides, sulfones, and local anesthetics, are derivatives of aniline, originally called "blue oil" or "kyanol." Some of these aniline derivatives, however, have also caused aplastic anemia, agranulocytosis, and methemoglobinemia (that is, "blue people"). Exposure to aniline drugs, particularly when two or three aniline drugs are taken concurrently, seems to be the commonest cause of methemoglobinemia today. PMID:8065194

  10. ‘No Blue’ White LED

    OpenAIRE

    Ou, Haiyan; Corell, Dennis Dan; Dam-Hansen, Carsten; Petersen, Paul Michael; Friis, Dan

    2010-01-01

    This paper explored the feasibility of making a white LED light source by color mixing method without using the blue color. This ‘no blue’ white LED has potential applications in photolithography room illumination, medical treatment and biophotonics research. A no-blue LED was designed, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that, colorimetric values were calculated and compared on terms of ...

  11. LED wireless

    OpenAIRE

    Pang, G.; Kwan, T.; Liu, H; Chan, CH

    2002-01-01

    High-brightness light-emitting diodes (LEDs) are getting more popular and are opening up a number of new applications. In this paper, the novel idea based on the fast switching of LEDs and the modulation of visible light is developed into a new kind of information system. A visible-LED audio system that makes use of visual-light rays to transmit audio messages to a remotely located receiver is described. Such a system made up of high-brightness visible LEDs can provide the function of open sp...

  12. Adsorption of Procion Blue MX-R dye from aqueous solutions by lignin chemically modified with aluminium and manganese

    Energy Technology Data Exchange (ETDEWEB)

    Adebayo, Matthew A. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Department of Chemical Sciences, Ajayi Crowther University, PMB 1066 Oyo, Oyo State (Nigeria); Prola, Lizie D.T. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Lima, Eder C., E-mail: eder.lima@ufrgs.br [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Puchana-Rosero, M.J.; Cataluña, Renato; Saucier, Caroline; Umpierres, Cibele S.; Vaghetti, Julio C.P. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Silva, Leandro G. da; Ruggiero, Reinaldo [Institute of Chemistry, Federal University of Uberlândia (UFU), AV. João Naves de Ávila 2121 block 1D—Campus Santa Mônica, 38400-902 Uberlândia, MG (Brazil)

    2014-03-01

    Graphical abstract: - Highlights: • Complexes of carboxy-methylated lignin with Al and Mn were used as adsorbents. • The optimum adsorption conditions were achieved at pH 2 and 298 K. • Maximum adsorption capacities are 73.52 mg g{sup −1} (CML-Al) and 55.16 mg g{sup −1} (CML-Mn). • CML-Al could remove ca. 95.83% of dye-contaminated industrial effluents. • CML-Al and CML-Mn are effective for treatment of simulated dye-house effluents. - Abstract: A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al{sup 3+} (CML-Al) and Mn{sup 2+} (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pH{sub PZC}. The established optimum pH and contact time were 2.0 and 5 h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16 mg g{sup −1} at 298 K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone + 50% of 0.05 mol L{sup −1} NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents.

  13. Adsorption of Procion Blue MX-R dye from aqueous solutions by lignin chemically modified with aluminium and manganese

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Complexes of carboxy-methylated lignin with Al and Mn were used as adsorbents. • The optimum adsorption conditions were achieved at pH 2 and 298 K. • Maximum adsorption capacities are 73.52 mg g−1 (CML-Al) and 55.16 mg g−1 (CML-Mn). • CML-Al could remove ca. 95.83% of dye-contaminated industrial effluents. • CML-Al and CML-Mn are effective for treatment of simulated dye-house effluents. - Abstract: A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al3+ (CML-Al) and Mn2+ (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pHPZC. The established optimum pH and contact time were 2.0 and 5 h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16 mg g−1 at 298 K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone + 50% of 0.05 mol L−1 NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents

  14. Removal of methylene blue from aqueous solutions by an adsorbent based on metal-organic framework and polyoxometalate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoxia; Luo, Jing; Zhu, Yating; Yang, Yun; Yang, Shuijin, E-mail: yangshuijin@163.com

    2015-11-05

    A metal-organic framework (Cu{sub 3}(BTC){sub 2}, BTC = 1,3,5-benzenetricarboxylate) composite based on polyoxometalate (H{sub 6}P{sub 2}W{sub 18}O{sub 62}) was synthesized by a simple one-pot solvent-thermal method and applied as an adsorbent to remove methylene blue (MB) from aqueous solution. The chemical structure, morphology and thermostability of the composite were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TG) and N{sub 2} adsorption–desorption isotherms. The removal rate of the composite H{sub 6}P{sub 2}W{sub 18}O{sub 62}@Cu{sub 3}(BTC){sub 2} was greater than that of the pure Cu{sub 3}(BTC){sub 2}, especially at higher initial concentrations, showing that the adsorption performance of porous Cu{sub 3}(BTC){sub 2} can be improved through the modification of H{sub 6}P{sub 2}W{sub 18}O{sub 62}. The effect factors containing the initial concentration, contact time, initial solution pH and temperature of MB adsorption onto the composite were systematically explored. The experimental isotherm data was found to fit the Freundlich model well and the process of MB adsorption onto H{sub 6}P{sub 2}W{sub 18}O{sub 62}@Cu{sub 3}(BTC){sub 2} was controlled by the pseudo-second-order kinetic model. The thermodynamic parameters illustrated that the adsorption was spontaneous and exothermic process. These results show that designing a metal-organic framework composite is a quite promising strategy to achieve extreme application for metal-organic framework. - Graphical abstract: Comparison of removal rate for MB in pure Cu{sub 3}(BTC){sub 2} and H{sub 6}P{sub 2}W{sub 18}O{sub 62}@Cu{sub 3}(BTC){sub 2} at different initial concentration. - Highlights: • Metal-organic framework (MOF) composite in the adsorption application was proposed. • The adsorption rate of MOF was improved by introducing polyoxometalates. • The adsorption isotherm and kinetic was used to

  15. An Overview of the Antecedents and Consequences of Abandoned Residential Housing Projects in Malaysia – A solution from Blue Ocean Strategy (BOS) Perspective

    OpenAIRE

    Mohd Hasyim Hj. Mumin; Fakhrul Anwar Zainol

    2015-01-01

    The issue of abandoned residential housing projects in Malaysia is a matter that should be given more importance in the country. This study aims to identify what are the causes, examine how it affects affected home buyers, and to suggest the solutions from Blue Ocean Strategy (BOS) Perspective. To achieve the goals, this study focused on reviewing relevant literatures and observing the site of abandoned housing projects. From the review of the literatures, the main objective is to find out wh...

  16. Postpartum Blues

    Medline Plus

    Full Text Available ... blues The postpartum blues E-mail to a friend Please fill in all fields. Please enter a ... blues: Talk to your partner or a good friend about how you feel Get plenty of rest ...

  17. Fast and highly-efficient removal of methylene blue from aqueous solution by poly(styrenesulfonic acid-co-maleic acid)-sodium-modified magnetic colloidal nanocrystal clusters

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yu-Bei; Lv, Shao-Nan; Cheng, Chang-Jing, E-mail: changjing_cheng@163.com; Ni, Guo-Li; Xie, Xiao-Wa; Huang, Wei; Zhao, Zhi-Gang

    2015-01-01

    Graphical abstract: - Highlights: • Magnetic colloid nanoclusters (MCNCs) are used for adsorption of methylene blue (MB). • The MCNCs exhibit fast and highly-efficient removal capacity for MB. • The MB adsorption onto the MCNCs is due to the strong electrostatic interactions. - Abstract: Magnetic colloidal nanocrystal clusters (MCNCs) modified with different amounts of poly(4-styrenesulfonic acid-co-maleic acid) sodium (PSSMA) have been prepared through simple one-step solvothermal method for removal of methylene blue (MB) from aqueous solution. The prepared MCNCs are characterized by Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), nitrogen adsorption–desorption technique and dynamic light scattering (DLS). Moreover, effects of the solution pH, contact time, adsorbent dosage, ionic strength and initial dye concentration on MB adsorption onto the MCNCs are systematically investigated. The PSSMA-modified MCNCs show fast and highly-efficient MB removal capacity, which dramatically depends on the immobilization amounts of PSSMA, solution pH and adsorbent dosage. Their adsorption kinetics and isotherms exhibit that the kinetics and equilibrium adsorptions can be well-described by pseudo-second-order kinetic and Langmuir model, respectively. These magnetic nanocomposites, with high separation efficiency, low production cost and recyclable property, are promising as functional adsorbents for efficient removal of cationic organic pollutants from aqueous solution.

  18. Fast and highly-efficient removal of methylene blue from aqueous solution by poly(styrenesulfonic acid-co-maleic acid)-sodium-modified magnetic colloidal nanocrystal clusters

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Magnetic colloid nanoclusters (MCNCs) are used for adsorption of methylene blue (MB). • The MCNCs exhibit fast and highly-efficient removal capacity for MB. • The MB adsorption onto the MCNCs is due to the strong electrostatic interactions. - Abstract: Magnetic colloidal nanocrystal clusters (MCNCs) modified with different amounts of poly(4-styrenesulfonic acid-co-maleic acid) sodium (PSSMA) have been prepared through simple one-step solvothermal method for removal of methylene blue (MB) from aqueous solution. The prepared MCNCs are characterized by Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), nitrogen adsorption–desorption technique and dynamic light scattering (DLS). Moreover, effects of the solution pH, contact time, adsorbent dosage, ionic strength and initial dye concentration on MB adsorption onto the MCNCs are systematically investigated. The PSSMA-modified MCNCs show fast and highly-efficient MB removal capacity, which dramatically depends on the immobilization amounts of PSSMA, solution pH and adsorbent dosage. Their adsorption kinetics and isotherms exhibit that the kinetics and equilibrium adsorptions can be well-described by pseudo-second-order kinetic and Langmuir model, respectively. These magnetic nanocomposites, with high separation efficiency, low production cost and recyclable property, are promising as functional adsorbents for efficient removal of cationic organic pollutants from aqueous solution

  19. Facile synthesis of pectin-stabilized magnetic graphene oxide Prussian blue nanocomposites for selective cesium removal from aqueous solution.

    Science.gov (United States)

    Kadam, Avinash A; Jang, Jiseon; Lee, Dae Sung

    2016-09-01

    This work focused on the development of pectin-stabilized magnetic graphene oxide Prussian blue (PSMGPB) nanocomposites for removal of cesium from wastewater. The PSMGPB nanocomposite showed an improved adsorption capacity of 1.609mmol/g for cesium, compared with magnetic graphene oxide Prussian blue, magnetic pectin Prussian blue, and magnetic Prussian blue nanocomposites, which exhibited adsorption capacities of 1.230, 0.901, and 0.330mmol/g, respectively. Increased adsorption capacity of PSMGPB nanocomposites was attributed to the pectin-stabilized separation of graphene oxide sheets and enhanced distribution of magnetites on the graphene oxide surface. Scanning electron microscopy images showed the effective separation of graphene oxide sheets due to the incorporation of pectin. The optimum temperature and pH for adsorption were 30°C and 7.0, respectively. A thermodynamic study indicated the spontaneous and the exothermic nature of cesium adsorption. Based on non-linear regression, the Langmuir isotherm fitted the experimental data better than the Freundlich and Tempkin models. PMID:27262093

  20. Uniform Cu{sub 2}Cl(OH){sub 3} hierarchical microspheres: A novel adsorbent for methylene blue adsorptive removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Wei; Gao, Pin; Xie, Jimin, E-mail: xiejm391@sohu.com; Zong, Sekai; Cui, Henglv; Yue, Xuejie

    2013-08-15

    Using the solution phase method without any surfactants or templates, the hierarchical of Cu{sub 2}Cl(OH){sub 3} microspheres were synthesized by freeze drying. The size and surface area of the microspheres are ca. 1–2 µm and 76.61 m{sup 2} g{sup −1}, respectively. A possible formation mechanism is presented based on the experimental results. Methylene blue was chosen to investigate the adsorption capacity of the as-prepared adsorbent. The effects of various experimental parameters, such as pH, initial dye concentration, and contact time were investigated. The results showed that the dye removal increased with the increasing in the initial concentration of the dye and also increased in the amount of microspheres used and initial pH. Adsorption data fitted well with the Freundlich adsorption isotherm. The thermodynamic analysis presented the exothermic, spontaneous and more ordered arrangement process. The microspheres could be employed effective for removal of dyes from aqueous solution. - Graphical abstract: The single-crystalline hierarchical Cu{sub 2}Cl(OH){sub 3} spheres can be prepared for the first time by using a template-free process through freeze-drying. Meanwhile, the hierarchical spheres exhibited high adsorption capacity to methylene blue. Display Omitted - Highlights: • Cu{sub 2}Cl(OH){sub 3} microspheres were successfully synthesized through a freeze drying process. • A possible formation mechanism of hierarchical microspheres was presented. • The Cu{sub 2}Cl(OH){sub 3} microspheres have high methylene blue adsorption capacity. • Methylene blue adsorption is a spontaneous and exothermic process. • The adsorption mechanism of microspheres onto dye was proposed in detail.

  1. Affordable underwater wireless optical communication using LEDs

    Science.gov (United States)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  2. REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION BY ACTIVATED CARBON PREPARED FROM THE PEEL OF CUCUMIS SATIVA FRUIT BY ADSORPTION

    OpenAIRE

    Manonmani Subbian; Santhi Thirumalisamy

    2010-01-01

    The use of low-cost, locally available, highly efficient, and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from the peel of Cucumis sativa fruit for the removal of methylene blue (MB) dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH, and contact time were inves...

  3. Removal of reactive blue 19 from aqueous solution by pomegranate residual-based activated carbon: optimization by response surface methodology

    OpenAIRE

    Radaei, Elham; Alavi Moghaddam, Mohammad Reza; Arami, Mokhtar

    2014-01-01

    Background In this research, response surface methodology (RSM) was applied to optimize Reactive Blue 19 removal by activated carbon from pomegranate residual. A 24 full factorial central composite design (CCD) was applied to evaluate the effects of initial pH, adsorbent dose, initial dye concentration, and contact time on the dye removal efficiency. Methodology The activated carbon prepared by 50 wt.% phosphoric acid activation under air condition at 500°C. The range of pH and initial dye co...

  4. SYNTHESIS AND CHARACTERIZATIONOF ORGANIC FUNCTIONALIZED MESOPOROUS SILICA AND EVALUATE THEIR ADSORPTIVE BEHAVIOR FOR REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    Sameer H. Kareem

    2014-01-01

    Full Text Available Three Mesoporous Silica (MPS with different functional groups were prepared by one-step synthesis based on the simultaneous hydrolysis and condensation of tetraethoxy silane with organo-silane in the presence of template surfactant Polydimethylsiloxane-Polyethyleneoxide (PDMS-PEO. The prepared materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR, Thermogravimetric Analysis (TGA and nitrogen adsorption-desorption experiments. The results indicate that the preparation of methyl and phenyl functionalized silica were successful. The adsorption behavior of methylene blue from aqueous systems onto these mesoporous silica has been studied. Batch experiments were carried out to measure the adsorption as a function of contact time, initial concentration (2.5-20 mg L-1 and temperature (288, 298, 308 and 318 K. The equilibrium of the process was achieved within (30-60 min. The adsorption of methylene blue on the mesoporous silica increases with increasing temperature which indicating an endothermic process. Adsorption isotherms were fitted with the Langmuir, Freundlich models. The kinetic data were analyzed using pseudo-first- order and pseudo-second-order models and intraparticle diffusion. The adsorption kinetics of methylene blue on mesoporous silica matched well with pseudo-second order kinetic model.

  5. Sequential study on reactive blue 29 dye removal from aqueous solution by peroxy acid and single wall carbon nanotubes: experiment and theory

    Directory of Open Access Journals (Sweden)

    Jahangiri-Rad Mahsa

    2013-01-01

    Full Text Available Abstract The majority of anthraquinone dye released to the environment come from antrapogenic sources. Several techniques are available for dyes' removal. In this study removal of reactive blue 29 (RB29 by an advanced oxidation process sequenced with single wall carbon nanotubes was investigated. Advanced oxidation process was optimized over a period of 60 minutes by changing the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2% -56.4% of reactive blue 29 was observed when the ratio of hydrogen peroxide/acetic acid/dye changed from 344/344/1 to 344/344/0.08 at different times (60, 120 and 180 min. The optimum ratio of acetic acid/hydrogen peroxide/dye was found to be 344/344/0.16 over 60 min. The resultant then was introduced for further removal by single wall carbon nanotubes(SWCNTs as adsorbent. The adsorption of reactive blue 29 onto SWCNTs was also investigated. Langmuir, Freundlich and BET isotherms were determined and the results revealed that the adsorption of RB29 onto SWCNTs was well explained by BET model and changed to Freundlich isotherm when SWCNTs was used after the application of peroxy acid. Kinetic study showed that the equilibrium time for adsorption of RB 29 on to SWCNT is 4 h. Experiments were carried out to investigate adsorption kinetics, adsorbent capacity and the effect of solution pH on the removal of reactive blue29. The pseudo-second order kinetic equation could best describe the sorption kinetics. The most efficient pH for color removal (amongst pH=3, 5 and 8 was pH= 5. Further studies are needed to identify the peroxy acid degradation intermediates and to investigate their effects on SWCNTs.

  6. Sequential study on Reactive Blue 29 Dye Removal from Aqueous Solution by Peroxy Acid and Single Wall Carbon Nanotubes: Experiment and Theory

    Directory of Open Access Journals (Sweden)

    Mahsa Jahangiri-Rad

    2012-01-01

    Full Text Available The majority of anthraquinone dye released to the environment come from antrapogenic sources. Several techniques are available for dyes' removal. In this study removal of reactive blue 29 (RB29 by an advanced oxidation process sequenced with single wall carbon nanotubes was investigated. Advanced oxidation process wasoptimized over a period of 60 minutes by changing the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2% -56.4% of reactive blue 29 was observed when the ratio of hydrogen peroxide/acetic acid/dye changed from 344/344/1 to 344/344/0.08 at different times (60, 120 and 180 min. Theoptimum ratio of acetic acid/hydrogen peroxide/dye was found to be 344/344/0.16 over 60 min. The resultant then was introduced for further removal by single wall carbon nanotubes(SWCNTs as adsorbent. The adsorption of reactive blue 29 onto SWCNTs was also investigated. Langmuir, Freundlich and BET isotherms were determined and the results revealed that the adsorption of RB29 onto SWCNTs was well explained by BET model and changed to Freundlich isotherm when SWCNTs was used after the application of peroxy acid. Kinetic study showed that the equilibrium time for adsorption of RB 29 on to SWCNT is 4 h. Experiments were carried out to investigate adsorption kinetics, adsorbent capacity and the effect of solution pH on the removal of reactive blue29. The pseudo-second order kinetic equation could best describe the sorption kinetics. The most efficient pH for colorremoval (amongst pH=3, 5 and 8 was pH= 5. Further studies are needed to identify the peroxy acid degradation intermediates and to investigate their effects on SWCNTs.

  7. LEDs/ALAN-Working To Be Good Neighbors

    Science.gov (United States)

    Adams, Robert

    2015-08-01

    ALAN (Artificial Light At Night) and LEDs have recently become major discussion topics in the areas of astronomy, light pollution, endangered species and human health to mention but a few. In years past, MH, LPS and HPS dominated night lighting with LPS and its associated narrow spectrum as the preferred source around observatories and shorelines. LEDs offer the ability to modify the spectrum, realize substantial energy savings and other associated benefits while meeting the requirements of the astronomy community.The primary concern of the different groups relates to blue light content of the LED. For astronomers, the molecular (Raleigh) scattering related to the blue light interferes with certain portions of the spectrum used for deep space studies. The ecologists studying various endangered species find blue and green light can be related to declining leatherback turtle population in certain areas of the world. Other animals ranging from bats to moths and other insects are now being studied to determine the effect of the blue light spectrum on their behavior. The impact of blue light on the human circadian rhythm and vision, especially in the older population, is being extensively studied today.This presentation will discuss the spectral power distribution (SPD) of various light sources, the performance of new LED solutions and how the SPD of these new LED’s can be adapted to address some of the issues raised by various constituencies. A discussion describing why some of the metrics used to describe standard lighting are not adequate for specifying the new LED solutions with the modified spectra will be included.Today, lighting plans and implementation are all too often based on opinions and limited data. The ensuing problems and repercussions make it imperative to collect accurate and thorough information. Data collection is now ongoing using a variety of techniques analyzing the “before” and “after” lighting results from the C of HI LED streetlight

  8. Removal of direct blue-106 dye from aqueous solution using new activated carbons developed from pomegranate peel: Adsorption equilibrium and kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Nevine Kamal, E-mail: nkamalamin@yahoo.com [Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria (Egypt)

    2009-06-15

    The use of cheap, high efficiency and ecofriendly adsorbent has been studied as an alternative source of activated carbon for the removal of dyes from wastewater. This study investigates the use of activated carbons prepared from pomegranate peel for the removal of direct blue dye from aqueous solution. A series of experiments were conducted in a batch system to assess the effect of the system variables, i.e. initial pH, temperature, initial dye concentration adsorbent dosage and contact time. The results showed that the adsorption of direct blue dye was maximal at pH 2, as the amount of adsorbent increased, the percentage of dye removal increased accordingly but it decreased with the increase in initial dye concentration and solution temperature. The adsorption kinetics was found to follow pseudo-second-order rate kinetic model, with a good correlation (R{sup 2} > 0.99) and intra-particle diffusion as one of the rate determining steps. Langmuir, Freundlich, Temkin, Dubinin-RadushKevich (D-R) and Harkins-Jura isotherms were used to analyze the equilibrium data at different temperatures. In addition, various thermodynamic parameters, such as standard Gibbs free energy ({Delta}G{sup o}), standard enthalpy ({Delta}H{sup o}), standard entropy ({Delta}S{sup o}), and the activation energy (E{sub a}) have been calculated. The adsorption process of direct blue dye onto different activated carbons prepared from pomegranate peel was found to be spontaneous and exothermic process. The findings of this investigation suggest that the physical sorption plays a role in controlling the sorption rate.

  9. Removal of direct blue-106 dye from aqueous solution using new activated carbons developed from pomegranate peel: Adsorption equilibrium and kinetics

    International Nuclear Information System (INIS)

    The use of cheap, high efficiency and ecofriendly adsorbent has been studied as an alternative source of activated carbon for the removal of dyes from wastewater. This study investigates the use of activated carbons prepared from pomegranate peel for the removal of direct blue dye from aqueous solution. A series of experiments were conducted in a batch system to assess the effect of the system variables, i.e. initial pH, temperature, initial dye concentration adsorbent dosage and contact time. The results showed that the adsorption of direct blue dye was maximal at pH 2, as the amount of adsorbent increased, the percentage of dye removal increased accordingly but it decreased with the increase in initial dye concentration and solution temperature. The adsorption kinetics was found to follow pseudo-second-order rate kinetic model, with a good correlation (R2 > 0.99) and intra-particle diffusion as one of the rate determining steps. Langmuir, Freundlich, Temkin, Dubinin-RadushKevich (D-R) and Harkins-Jura isotherms were used to analyze the equilibrium data at different temperatures. In addition, various thermodynamic parameters, such as standard Gibbs free energy (ΔGo), standard enthalpy (ΔHo), standard entropy (ΔSo), and the activation energy (Ea) have been calculated. The adsorption process of direct blue dye onto different activated carbons prepared from pomegranate peel was found to be spontaneous and exothermic process. The findings of this investigation suggest that the physical sorption plays a role in controlling the sorption rate.

  10. Multi-3,3'-Bicarbazole-Substituted Arylsilane Host Materials with Balanced Charge Transport for Highly Efficient Solution-Processed Blue Phosphorescent Organic Light-Emitting Diodes.

    Science.gov (United States)

    Sun, Dianming; Zhou, Xiaokang; Li, Huihui; Sun, Xiaoli; Ren, Zhongjie; Ma, Dongge; Yan, Shouke

    2015-08-19

    A series of 3,3'-bicarbazole (mCP)-functionalized tetraphenylsilane derivatives (SimCPx), including bis(3,5-di(9H-carbazol-9-yl)phenyl)diphenylsilane (SimCP2), tris(3,5-di(9H-carbazol-9-yl)phenyl)methylsilane (SimCP3-CH3), tris(3,5-di(9H-carbazol-9-yl)phenyl)phenylsilane (SimCP3-Ph), and tetrakis(3,5-di(9H-carbazol-9-yl)phenyl)silane (SimCP4), serving as bipolar blue hosts for bis[2-(4,6-difluorophenyl)pyridyl-N,C2']iridium(III) (FIrpic), have been synthesized by incorporating different ratios of mCP subunits into a central silicon atom. All of the SimCPx derivatives have wide bandgaps and high triplet energies because of the indirect linkage by silicon between each mCP subunit. The good solubility and high thermal and morphological stability of SimCPx are beneficial for forming amorphous and homogeneous films through solution processing. Density functional theory simulations manifest the better bipolar characteristics for SimCPx using three and four mCP units rather than the represented bipolar host SimCP2. As a result, SimCP4 presents the best electron-transporting ability for charge balance. Consequently, the lowest driving voltage of 4.8 eV, and the favorable maximum efficiencies of 14.2% for external quantum efficiency (28.4 cd A(-1), 13.5 lm W(-1)), are achieved by solution-processed, SimCP4-based blue phosphorescent organic light-emitting diodes as the highest performance among SimCPx, in which 32% improved device efficiencies compared to that of SimCP2 are obtained. It is inspiring to develop efficient bipolar hosts for blue phosphors by just incorporating monopolar carbazole into arylsilanes in two steps. PMID:26252613

  11. Novel tannin-based adsorbent in removing cationic dye (Methylene Blue) from aqueous solution. Kinetics and equilibrium studies.

    Science.gov (United States)

    Sánchez-Martín, J; González-Velasco, M; Beltrán-Heredia, J; Gragera-Carvajal, J; Salguero-Fernández, J

    2010-02-15

    Natural tannin-based adsorbent has been prepared on the basis of the gelification of Quebracho bark extract. The resulting product, Quebracho Tannin Gel (QTG) was tested as cationic dye adsorbent with Methylene Blue (MB). Kinetics of adsorption process were studied out and a period of 15 days was determined for reaching equilibrium. The influences of pH and temperature were evaluated. As pH or temperature raise q capacity of QTG increases. Theoretical modelization of dye-QTG adsorption was carried out by multiparametric adjustment according to Langmuir's hypothesis. Values of the k(l1), k(l2) and activation energies were calculated. PMID:19782466

  12. ADSORPTION OF METHYLENE BLUE FROM AQUEOUS SOLUTION ON ACTIVATED CARBON PRODUCED FROM SOYBEAN OIL CAKE BY KOH ACTIVATION

    OpenAIRE

    Turgay Tay; Murat Erdem; Burak Ceylan,; Selhan Karagöz

    2012-01-01

    This study presents the adsorption behavior of the methylene blue (MB) dye onto the activated carbon produced from soybean oil cake by chemical activation with KOH at 800 °C. The adsorption isotherms, kinetic models, and thermodynamic parameters of the adsorption were studied. The Langmuir isotherm showed a better fit than the Freundlich isotherm. The adsorption rate was described by pseudo-second-order kinetics. The negative values of ΔG° and the positive values of ΔH° indicate that the adso...

  13. Postpartum Blues

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    Full Text Available ... Quality Collaboratives Launch Prematurity research centers What is team science? More than 75 years of solving problems ... delivery cause the postpartum blues. How can you manage the baby blues? The American College of Obstetricians ...

  14. Postpartum Blues

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    Full Text Available ... with this condition are happy most of the time. But compared to how she usually feels, the ... the "blues" usually lessens and goes away over time. What causes the baby blues? Medical experts believe ...

  15. Postpartum Blues

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    Full Text Available ... Postpartum care > The postpartum blues The postpartum blues E-mail to a friend Please fill in all fields. Please enter a valid e-mail address. Your information: Your recipient's information: Your ...

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    Full Text Available ... usually lessens and goes away over time. What causes the baby blues? Medical experts believe that changes ... usually lessens and goes away over time. What causes the baby blues? Medical experts believe that changes ...

  17. Postpartum Blues

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    Full Text Available ... Feels sad Feels confused The postpartum blues peak three to five days after delivery. They usually end ... Feels sad Feels confused The postpartum blues peak three to five days after delivery. They usually end ...

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  19. Postpartum Blues

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    Full Text Available ... The postpartum blues The postpartum blues Now playing: E-mail to a friend Please fill in all fields. Please enter a valid e-mail address. Your information: Your recipient's information: Your ...

  20. Postpartum Blues

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    Full Text Available ... of Obstetricians and Gynecologists recommends that women do these things to help relieve the baby blues: Talk ... of Obstetricians and Gynecologists recommends that women do these things to help relieve the baby blues: Talk ...

  1. Postpartum Blues

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    Full Text Available ... Medical experts believe that changes in the woman's hormones after delivery cause the postpartum blues. How can ... Medical experts believe that changes in the woman's hormones after delivery cause the postpartum blues. How can ...

  2. Postpartum Blues

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    Full Text Available ... can you manage the baby blues? The American College of Obstetricians and Gynecologists recommends that women do ... can you manage the baby blues? The American College of Obstetricians and Gynecologists recommends that women do ...

  3. Postpartum Blues

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    Full Text Available ... postpartum blues The postpartum blues E-mail to a friend Please fill in all fields. Please enter ... hear about breakthroughs for babies and families. Ask a question Our health experts can answer questions about ...

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  5. Removal of Evans Blue and Yellow thiazole dyes from aqueous solution by Mg-Al-CO3 Layered Double Hydroxides as anion-exchanger

    Directory of Open Access Journals (Sweden)

    Mohamed Bouraada

    2014-06-01

    Full Text Available Mg-Al-CO3 Layered double hydroxide (LDH was prepared by co-precipitation method at constant pH, and subsequently used to remove Evans Blue (EB and Yellow thiazole (YT dyes from aqueous solutions. The obtained material was characterized by powder X-ray diffraction (PXRD, Fourier transform infrared spectroscopy (FTIR, thermal analysis and BET. The kinetic and equilibrium aspects of sorption of the anionic dyes from aqueous solution by Mg-Al-CO3 were investigated in batch mode. The sorption kinetic data were found to be consistent with the pseudo-second-order model. Data for YT and EB sorption by Mg-Al-CO3 were fitted better by the Langmuir equation than by the Freundlich equation based on the determination coefficient values R2 . The maximum adsorption capacities of 222.2 mgg-1 for Yellow thiazole and 107.5 mgg-1 for Evans blue. The thermodynamic parameters including Gibbs free energy (G°, standard enthalpy change (H°, and standard entropy change (S° for the process were calculated. The negative G° value indicates the spontaneity of the removal process.

  6. Comparative Study for Adsorptive Removal of Coralene Blue BGFS Dye from Aqueous Solution by MgO and Fe2O3 as an Adsorbent

    Directory of Open Access Journals (Sweden)

    Parth Desai,

    2014-07-01

    Full Text Available Textile industries represent biggest impact on the environment due to high water consumption and waste water discharge as government control water pollution by setting strength regulation for waste water discharge, removal of color from waste water becomes more and more essential and attractive. Adsorption technology is very efficient in treatment of textile effluent. In this paper comparison of adsorption phenomena of textile dye Anthraquinone blue onto two different adsorbents MgO nano powder and Fe2O3 amorphous powder has been studied for removal of said dye from aqueous solutions. The adsorption of Anthraquinone blue on adsorbents occurs by studying the effects of adsorbent amount, dye concentration, contact time and pH of solution. All results found that MgO nano powder and Fe2O3 provide a fairly high dye adsorption capacity, which combined with their fulfilment of pollution control board’s standards, lack of pollution, lower environmental hazard and low-cost makes them promising for future applications. The present work also provides information on optimum value of different operating parameter for dye removal by two adsorbent.

  7. Adsorptive removal and kinetics of methylene blue from aqueous solution using NiO/MCM-41 composite

    Science.gov (United States)

    Xiao, Xuechun; Zhang, Fei; Feng, Zhipeng; Deng, Shaojuan; Wang, Yude

    2015-01-01

    Highly ordered mesoporous material MCM-41 was synthesized from tetraethylorthosilicate (TEOS) as Si source and cetyltrimethylammonium bromide (CTAB) as template. Well-dispersed NiO nanoparticles were introduced into the highly ordered mesoporous MCM-41 by chemical precipitation method to prepare the highly ordered mesoporous NiO/MCM-41 composite. X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and high-resolution TEM (HRTEM), and nitrogen adsorption-desorption measurement were used to examine the morphology and the microstructure of the obtained composite. The morphological study clearly revealed that the synthesized NiO/MCM-41 composite has a highly ordered mesoporous structure with a specific surface area of 435.9 m2 g-1. A possible formation mechanism is preliminary proposed for the formation of the nanostructure. The adsorption performance of NiO/MCM-41 composite as an adsorbent was further demonstrated in the removal azo dyes of methyl orange (MO), Congo red (CR), methylene blue (MB) and rhodaming B (RB) under visible light irradiation and dark, respectively. The kinetics and mechanism of removal methylene blue were studied. The results show that NiO/MCM-41 composite has a good removal capacity for organic pollutant MB from the wastewater under the room temperature. Compared with MCM-41 and NiO nanoparticles, 54.2% and 100% higher removal rate were obtained by the NiO/MCM-41 composite.

  8. 丹参酮胶囊联合欧美娜红蓝光治疗仪治疗痤疮43例%Observation on the clinical efficacy of tanshinone capsules and Omnilux blue-red LED phototherapy combination in the treatment of acne

    Institute of Scientific and Technical Information of China (English)

    马静; 温炬; 冯洁莹; 郑荣昌

    2012-01-01

    Objective:To observe the therapeutic effect of the combination tanshinone capsules and Omnilux blue-red LED in treatment of patients with minor or medium degree acne. Methods:86 cases of minor or medium degree of acne were randomly divided into two groups, 43 patients as treating group were given 4 grains tanshinone capsule 3 times a day,PO, after 4 weeks, at the same time treated with Omnilux blue-red LED ,2 times a week,20 minutes a times. The other 43 patients as control group were treated with Omnilux blue-red LED only. Results:The effective rate of treating group was 79. 07% ,while that of control group was 53. 48%. The difference of effective rate in two groups was significant(P<0. 05). Conclusion:Combination tanshinone with Omnilux blue-red LED appears to have better curative rate and effective rate than Omnilux blue-red LED in treating only.%目的:观察丹参酮联合欧美娜红蓝光治疗仪对轻中度痤疮的治疗效果.方法:86例轻、中度寻常痤疮患者分为两组,治疗组口服丹参酮4粒/次,3次/d,联合欧美娜红蓝光治疗仪照射,每次治疗时间 20min,红蓝光交替照射,每周2次,共8次为1个疗程.对照组单纯红蓝光照射治疗,4周后判定疗效.结果:治疗组和对照组有效率分别为79.07%和53.48%,两组疗效比较差异有统计学意义(P<0.05).结论:丹参酮联合欧美娜红蓝光治疗轻、中度痤疮疗效好,不良反应小,值得推广.

  9. Removal of the blue 1 dye of aqueous solutions using ferric zeolite; Remocion del colorante azul 1 de soluciones acuosas utilizando zeolita ferrica

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo H, S. Y.

    2010-07-01

    Water is essential to all life forms, including humans. In recent years water use has increased substantially, also has been altered in its capacity as a result of various human activities, such as domestic, industrial and agricultural, also by natural activity. Undoubtedly one of the main pollutants today are the waste generated by the food industry, due to the use of dyes for the production of their products. So it is necessary to restore water quality through treatment systems to remove contaminants, and thus prevent disease and imbalance of ecosystems. Due to the above, it is important to conduct research directed towards finding new ways to remove dyes such as blue 1 used in the food industry, using low cost materials and abundant in nature as zeolites. To accomplish the above, the present study has the purpose to evaluate the adsorption capacity of the blue dye 1 in aqueous solutions. To accomplish that objective, the zeolite material was reconditioned to improve its sorption properties of the material and provide the ability to adsorb pollutants such as this dye. The zeolite material was characterized by scanning electron microscopy and elemental analysis, X-ray diffraction and infrared spectroscopy. To evaluate the ability of blue 1 dye sorption the kinetics and sorption isotherms were determined; the experimental results were adjusted to mathematical models such as pseudo-first order, pseudo second order and Elovich to describe the kinetic process, and the Langmuir, Freundlich and Langmuir-Freundlich to describe sorption isotherms. The results showed that ferric zeolite surface is a heterogeneous material and has a considerable adsorption capacity, which makes it a potential adsorbent for removing color from aqueous streams. Also the sorption of the dye was evaluated at different ph values; the most sorption was carried out at ph values 1, 3 and 11. We also evaluated the change in mass where the sorption capacities for the blue 1 increase by increasing

  10. REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION BY ACTIVATED CARBON PREPARED FROM THE PEEL OF CUCUMIS SATIVA FRUIT BY ADSORPTION

    Directory of Open Access Journals (Sweden)

    Manonmani Subbian

    2010-02-01

    Full Text Available The use of low-cost, locally available, highly efficient, and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from the peel of Cucumis sativa fruit for the removal of methylene blue (MB dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH, and contact time were investigated, and optimal experimental conditions were ascertained. The results showed that as the amount of the adsorbent increased, the percentage of dye removal increased accordingly. The optimum pH for dye adsorption was 6.0. Maximum dye was sequestered within 50 min of the start of each experiment. The adsorption of methylene blue followed the pseudo-second-order rate equation and fit the Langmuir, Freundlich, Dubinin-Radushekevich (D-R, and Tempkin equations well. Maximum removal of MB was obtained at pH 6 as 99.79% for adsorbent doses of 0.6 g/ 50 mL and 25 mg/L initial dye concentrations at room temperature. The maximum adsorption capacity obtained from the Langmuir equation was 46.73 mg g-1. The rate of adsorption was found to conform to pseudo-second-order kinetics with a good correlation (R2 > 0.9677 with intraparticle diffusion as one of the rate-determining steps. Activated carbon developed from the peel of Cucumis sativa fruit can be an attractive option for dye removal from wastewater.

  11. Synthesis and photoluminescence characteristics of (Y,Gd)BO3:RE (RE = Eu(3+), Ce(3+), Dy(3+) and Tb(3+)) phosphors for blue chip and near-UV white LEDs.

    Science.gov (United States)

    Rangari, V V; Singh, V; Dhoble, S J

    2016-03-01

    A series of Eu(3+)-, Ce(3+)-, Dy(3+)- and Tb(3+)-doped (Y,Gd)BO3 phosphors was synthesized by a solid-state diffusion method. X-Ray diffraction confirmed their hexagonal structure and the scanning electron microscopy results showed crystalline particles. The excitation spectra revealed that (Y,Gd)BO3 phosphors doped with Eu(3+), Ce(3+), Dy(3+) and Tb(3+) are effectively excited with near UV-light of 395 nm/blue light, 364, 351 and 314 nm, respectively. Photoluminescence spectra of Eu(3+)-, Ce(3+)- and Tb(3+)/Dy(3+)-doped phosphor showed intense emission of reddish orange, blue and white light, respectively. The phosphor Y0.60Gd0.38BO3:Ce0.02 showed CIE 1931 color coordinates of (0.158, 0.031) and better color purity compared with commercially available blue BAM:Eu(2+) phosphor. The phosphor (Y,Gd)BO3 doped with Eu(3+), Dy(3+) and Tb(3+) showed CIE 1931 color coordinates of (0.667, 0.332), (0.251, 0.299) and (0.333, 0.391) respectively. Significant photoluminescence characteristics of the prepared phosphors indicate that they might serve as potential candidates for blue chip and near-UV white light-emitting diode applications. PMID:25991566

  12. Fast and highly-efficient removal of methylene blue from aqueous solution by poly(styrenesulfonic acid-co-maleic acid)-sodium-modified magnetic colloidal nanocrystal clusters

    Science.gov (United States)

    Song, Yu-Bei; Lv, Shao-Nan; Cheng, Chang-Jing; Ni, Guo-Li; Xie, Xiao-Wa; Huang, Wei; Zhao, Zhi-Gang

    2015-01-01

    Magnetic colloidal nanocrystal clusters (MCNCs) modified with different amounts of poly(4-styrenesulfonic acid-co-maleic acid) sodium (PSSMA) have been prepared through simple one-step solvothermal method for removal of methylene blue (MB) from aqueous solution. The prepared MCNCs are characterized by Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), nitrogen adsorption-desorption technique and dynamic light scattering (DLS). Moreover, effects of the solution pH, contact time, adsorbent dosage, ionic strength and initial dye concentration on MB adsorption onto the MCNCs are systematically investigated. The PSSMA-modified MCNCs show fast and highly-efficient MB removal capacity, which dramatically depends on the immobilization amounts of PSSMA, solution pH and adsorbent dosage. Their adsorption kinetics and isotherms exhibit that the kinetics and equilibrium adsorptions can be well-described by pseudo-second-order kinetic and Langmuir model, respectively. These magnetic nanocomposites, with high separation efficiency, low production cost and recyclable property, are promising as functional adsorbents for efficient removal of cationic organic pollutants from aqueous solution.

  13. Adsorption and photodegradation of methylene blue by iron oxide impregnated on granular activated carbons in an oxalate solution

    Energy Technology Data Exchange (ETDEWEB)

    Kadirova, Zukhra C., E-mail: zuhra_kadirova@yahoo.com [Institute of General and Inorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Mirzo Ulugbek Str. 77a, Tashkent 100170 (Uzbekistan); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Katsumata, Ken-ichi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Isobe, Toshihiro [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Matsushita, Nobuhiro [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Nakajima, Akira [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan); Okada, Kiyoshi [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan)

    2013-11-01

    The photocatalytic adsorbents BAU-OA, BAU-CL and BAU-HA with varying iron oxide content (9–10 mass%) were prepared by heat treatment at 250 °C from commercial activated carbon (BAU) impregnated with iron oxalate, chloride, tris-benzohydroxamate, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample (S{sub BET} 50 m{sup 2}/g) and low crystallinity (as FeOOH and Fe{sub 2}O{sub 3} phases) in the BAU-HA and BAU-OA samples (S{sub BET} 4 and 111 m{sup 2}/g, respectively). The methylene blue adsorption capacities was decreased in order of BAU-OA < BAU-CL < BAU-HA sample and the adsorption followed Langmuir model. The apparent MB photodegradation rate constant (k{sub app}) was increased in same order BAU-HA < BAU-CL < BAU-OA under the standard experimental conditions (initial MB concentrations 0.015–0.025 mM; sample content – 10 mg/l; initial oxalic acid concentration – 0.43 mM; pH 3–4; UV illumination). The process included high efficiency combination of adsorption, heterogeneous and homogeneous catalysis under UV and solar lights illumination without addition of hydrogen peroxide. The detoxification of water sample containing organic dyes was confirmed after combined sorption-photocatalytic treatment.

  14. Adsorption and photodegradation of methylene blue by iron oxide impregnated on granular activated carbons in an oxalate solution

    Science.gov (United States)

    Kadirova, Zukhra C.; Katsumata, Ken-ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Okada, Kiyoshi

    2013-11-01

    The photocatalytic adsorbents BAU-OA, BAU-CL and BAU-HA with varying iron oxide content (9-10 mass%) were prepared by heat treatment at 250 °C from commercial activated carbon (BAU) impregnated with iron oxalate, chloride, tris-benzohydroxamate, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample (SBET 50 m2/g) and low crystallinity (as FeOOH and Fe2O3 phases) in the BAU-HA and BAU-OA samples (SBET 4 and 111 m2/g, respectively). The methylene blue adsorption capacities was decreased in order of BAU-OA kapp) was increased in same order BAU-HA < BAU-CL < BAU-OA under the standard experimental conditions (initial MB concentrations 0.015-0.025 mM; sample content - 10 mg/l; initial oxalic acid concentration - 0.43 mM; pH 3-4; UV illumination). The process included high efficiency combination of adsorption, heterogeneous and homogeneous catalysis under UV and solar lights illumination without addition of hydrogen peroxide. The detoxification of water sample containing organic dyes was confirmed after combined sorption-photocatalytic treatment.

  15. FAST TRACK COMMUNICATION: Intense violet-blue emitting (CaCl2/SiO2) : Eu2+ phosphor powders for applications in UV-LED based phototherapy illuminators

    Science.gov (United States)

    Hao, Zhendong; Zhang, Jiahua; Zhang, Xia; Ren, Xinguang; Luo, Yongshi; Lu, Shaozhe; Wang, Xiaojun

    2008-09-01

    An intense violet-blue emitting (CaCl2/SiO2) : Eu2+ phosphor with a composition of 25% CaCl2 and 75% SiO2 is prepared by a solid state reaction. The phosphor emits at 427 nm with a narrow bandwidth of 21 nm. The photoluminescence (PL) intensities and fluorescence lifetimes are studied as a function of Eu2+ concentrations. It is observed that the PL intensity of (CaCl2/SiO2) : Eu2+ can be 30% higher than that of commercial Sr2P2O7 : Eu2+ phosphor under 395 nm excitation. (CaCl2/SiO2) : Eu2+ would be a promising new phosphor for converting near-ultraviolet radiation to violet-blue emission for a novel phototherapy illuminator using a near-ultraviolet (~395 nm) light emitting diode as the excitation source.

  16. Effects of Red and Blue Illumination from Light-emitting Diode(LED)on Seedling Quality of Different Rice Cultivars%发光二极管(LED)红蓝光照对不同水稻品种秧苗素质的影响

    Institute of Scientific and Technical Information of China (English)

    王国莉; 宋冠华; 黄素杏; 朱晓霞

    2014-01-01

    In order to probe the illumination-requirement law of raising rice seedlings and promote the factory production of raising rice seedlings,two rice cultivars(Hefeng and Huangxiu)were used to study the effect of red and blue illumination from light emitting diode(LED)on the quality of seedlings.The results showed that seedlings growth was affected by LED red or blue illumination treatment,leading to the decreased quality of seedlings compared with CK(conventional fluorescent light).Total content of photosynthetic pigments decreased more under long-time LED blue illumination than under LED red illumination,while the contents of chlorophyll a and carotenoid maintained a higher level in treatment of LED red illumination.Further study showed that blue illumination treatment inhibited the root elongation,root length and plant height of rice seedlings,but increased the root number,stem thickness and dry matter accumulation,so the sound seedling index was superior to that of red illumination treatment.It implied that LED monochrome blue or red illumination would not meet the illumination requirement in factory production of raising rice seedlings.%为探讨水稻育秧的光需求规律,促进水稻工厂化育秧的开展,以合丰和黄秀2个水稻品种为材料,研究了发光二极管(LED)红蓝单色光照对水稻秧苗素质的影响。结果表明,LED 红蓝单色光长时间照射水稻秧苗,会影响秧苗的正常生长,导致秧苗素质较对照(普通荧光灯)下降。与红光处理相比,蓝光处理的水稻秧苗的光合色素含量下降较快,但使体内叶绿素 a 和类胡萝卜素含量维持在较高水平。蓝光处理抑制水稻秧苗的伸长生长,根长、株高都低于红光处理,却可以增加秧苗根数、茎粗,增加干物质积累,使壮苗指数等秧苗素质指标优于红光处理。这说明红蓝单色 LED光源不能作为独立光源用于水稻工厂化育秧。

  17. Photodegradation of indigo carmine and methylene blue dyes in aqueous solution by SiC–TiO2 catalysts prepared by sol–gel

    International Nuclear Information System (INIS)

    Highlights: ► Photodegradation of organic dyes is possible using sol–gel SiC–TiO2 catalysts. ► SiC–TiO2 makes a synergy effect that enhances its catalytic activity. ► Sol–gel allows good dispersion and attachment of TiO2 particles on SiC surface. ► SiC–TiO2 exhibits better activity than TiO2 (P25) on organic dyes degradation. ► SiC–TiO2 catalysts are settled down and easily separated after photocatalysis. - Abstract: Indigo carmine and methylene blue dyes in aqueous solution were photodegraded using SiC–TiO2 catalysts prepared by sol–gel method. After thermal treatment at 450 °C, SiC–TiO2 catalysts prepared in this work showed the presence of SiC and TiO2 anatase phase. Those compounds showed specific surface area values around 22–25 m2 g−1, and energy band gap values close to 3.05 eV. In comparison with TiO2 (P25), SiC–TiO2 catalysts showed the highest activity for indigo carmine and methylene blue degradation, but this activity cannot be attributed to the properties above mentioned. Therefore, photocatalytic performance is due to the synergy effect between SiC and TiO2 particles caused by the sol–gel method used to prepare the SiC–TiO2 catalysts. TiO2 nanoparticles are well dispersed onto SiC surface allowing the transfer of electronic charges between SiC and TiO2 semiconductors, which avoid the fast recombination of the electron–hole pair during the photocatalytic process.

  18. Intense violet-blue emitting (CaCl{sub 2}/SiO{sub 2}) : Eu{sup 2+} phosphor powders for applications in UV-LED based phototherapy illuminators

    Energy Technology Data Exchange (ETDEWEB)

    Hao Zhendong; Zhang Jiahua; Zhang Xia; Ren Xinguang; Luo Yongshi; Lu Shaozhe; Wang Xiaojun [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, 16 Eastern South Lake Road, Changchun 130033 (China)], E-mail: zhangjh@ciomp.ac.cn

    2008-09-21

    An intense violet-blue emitting (CaCl{sub 2}/SiO{sub 2}) : Eu{sup 2+} phosphor with a composition of 25% CaCl{sub 2} and 75% SiO{sub 2} is prepared by a solid state reaction. The phosphor emits at 427 nm with a narrow bandwidth of 21 nm. The photoluminescence (PL) intensities and fluorescence lifetimes are studied as a function of Eu{sup 2+} concentrations. It is observed that the PL intensity of (CaCl{sub 2}/SiO{sub 2}) : Eu{sup 2+} can be 30% higher than that of commercial Sr{sub 2}P{sub 2}O{sub 7} : Eu{sup 2+} phosphor under 395 nm excitation. (CaCl{sub 2}/SiO{sub 2}) : Eu{sup 2+} would be a promising new phosphor for converting near-ultraviolet radiation to violet-blue emission for a novel phototherapy illuminator using a near-ultraviolet ({approx}395 nm) light emitting diode as the excitation source. (fast track communication)

  19. Postpartum Blues

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    Full Text Available ... leader Partner Spotlight Become a partner World Prematurity Day Your support helps babies We are determined to ... confused The postpartum blues peak three to five days after delivery. They usually end by the tenth ...

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    Full Text Available ... Saving Just a moment, please. You've saved this page It's been added to your dashboard . After ... blues" is not really correct since women with this condition are happy most of the time. But ...

  1. Postpartum Blues

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    Full Text Available ... dashboard . After the baby is born, many new mothers have the postpartum blues (also called the baby ... compared to how she usually feels, the new mother: Is more irritable Cries more easily Feels sad ...

  2. Postpartum Blues

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    Full Text Available ... articles March of Dimes Premature Birth Report Card Grades Cities, Counties; Focuses on Racial and Ethnic Disparities ... baby blues: Talk to your partner or a good friend about how you feel Get plenty of ...

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    Full Text Available ... leader Partner Spotlight Become a partner World Prematurity Day World Prematurity Your support helps babies We are ... confused The postpartum blues peak three to five days after delivery. They usually end by the tenth ...

  4. Postpartum Blues

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    Full Text Available ... for your baby Feeding your baby Common illnesses New parents Family health & safety Complications & Loss Pregnancy complications ... your dashboard . After the baby is born, many new mothers have the postpartum blues (also called the ...

  5. Stabilization of a magnetic nano-adsorbent by extracted pectin to remove methylene blue from aqueous solution: A comparative studying between two kinds of cross-likened pectin

    Energy Technology Data Exchange (ETDEWEB)

    Rakhshaee, Roohan, E-mail: rakhshaei@iaurasht.ac.ir [Department of Applied Chemistry, Faculty of Science, Islamic Azad University, Rasht Branch, P.O. Box 41335-3516, Rasht (Iran, Islamic Republic of); Panahandeh, Mohammad [Environmental Research Institute of Jahad Daneshgahi (Iran, Islamic Republic of)

    2011-05-15

    The removal of methylene blue (MB) as a cationic dye from aqueous solution by the stabilized Fe{sub 3}O{sub 4} nano-particles with the extracted pectin from apple waste (FN-PA) increased due to using the cross-linked forms of the bound pectin on the nano-particles surface by glutaraldehyde (FN-PAG) and adipic acid (FN-PAA) as the cross-linking agents. This increase happened in spite of binding some of the adsorbent functional groups of pectin with nano-particles. It can be due to the local concentrate of other free functional groups after connecting with nano-scale particles. Thermodynamic studies showed that the adsorption equilibrium constant and the maximum adsorption capacities increased with increasing temperature for all of the nano-bioparticles. The kinetic followed the second-order models with the highest rate constants viz. 16.23, 19.76 and 23.04 (x10{sup -3} g/mg min) by FN-PAA. The adsorption force arrangement of MB by these nano-biosorbents regarding their activation energy was obtained as: FN-PAA > FN-PAG > FN-PA.

  6. Stabilization of a magnetic nano-adsorbent by extracted pectin to remove methylene blue from aqueous solution: A comparative studying between two kinds of cross-likened pectin

    International Nuclear Information System (INIS)

    The removal of methylene blue (MB) as a cationic dye from aqueous solution by the stabilized Fe3O4 nano-particles with the extracted pectin from apple waste (FN-PA) increased due to using the cross-linked forms of the bound pectin on the nano-particles surface by glutaraldehyde (FN-PAG) and adipic acid (FN-PAA) as the cross-linking agents. This increase happened in spite of binding some of the adsorbent functional groups of pectin with nano-particles. It can be due to the local concentrate of other free functional groups after connecting with nano-scale particles. Thermodynamic studies showed that the adsorption equilibrium constant and the maximum adsorption capacities increased with increasing temperature for all of the nano-bioparticles. The kinetic followed the second-order models with the highest rate constants viz. 16.23, 19.76 and 23.04 (x10-3 g/mg min) by FN-PAA. The adsorption force arrangement of MB by these nano-biosorbents regarding their activation energy was obtained as: FN-PAA > FN-PAG > FN-PA.

  7. Photo catalytic property of ZnO and Mn-ZnO nanoparticles in removal of Cibacet Turquoise blue G from aquatic solution

    Directory of Open Access Journals (Sweden)

    Navid Assi

    2013-03-01

    Full Text Available ZnO and Mn-ZnO nano powders were prepared by the sol-gel auto combustion method. The products were characterized by X-ray diffraction (XRD, energy dispersive analysis of X-ray (EDX and scanning electron microscopy (SEM. Structural and morphological properties of nano particles were investigated and the average crystalline size of ZnO and Mn-doped ZnO was obtained 44 and 51 nm, respectively. Also, photo catalytic removal of Cibacen Turquoise Blue G dye from aqueous solution by using nano scale ZnO and Mn-ZnO powders under UV light irradiation was studied. The effect of initial dye concentrations and dosage of photo catalysts, were investigated in the photo destructive process. This is 57% of dye degraded by 0.02 mg of ZnO in 70 minutes. The degradation rate increase to 84% in the presence of 0.02 mg of Mn-ZnO in the same time.

  8. Photodegradation of indigo carmine and methylene blue dyes in aqueous solution by SiC-TiO{sub 2} catalysts prepared by sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Solis, Christian [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Juarez-Ramirez, Isaias, E-mail: isajua13@yahoo.com [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Moctezuma, Edgar [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Torres-Martinez, Leticia M. [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Photodegradation of organic dyes is possible using sol-gel SiC-TiO{sub 2} catalysts. Black-Right-Pointing-Pointer SiC-TiO{sub 2} makes a synergy effect that enhances its catalytic activity. Black-Right-Pointing-Pointer Sol-gel allows good dispersion and attachment of TiO{sub 2} particles on SiC surface. Black-Right-Pointing-Pointer SiC-TiO{sub 2} exhibits better activity than TiO{sub 2} (P25) on organic dyes degradation. Black-Right-Pointing-Pointer SiC-TiO{sub 2} catalysts are settled down and easily separated after photocatalysis. - Abstract: Indigo carmine and methylene blue dyes in aqueous solution were photodegraded using SiC-TiO{sub 2} catalysts prepared by sol-gel method. After thermal treatment at 450 Degree-Sign C, SiC-TiO{sub 2} catalysts prepared in this work showed the presence of SiC and TiO{sub 2} anatase phase. Those compounds showed specific surface area values around 22-25 m{sup 2} g{sup -1}, and energy band gap values close to 3.05 eV. In comparison with TiO{sub 2} (P25), SiC-TiO{sub 2} catalysts showed the highest activity for indigo carmine and methylene blue degradation, but this activity cannot be attributed to the properties above mentioned. Therefore, photocatalytic performance is due to the synergy effect between SiC and TiO{sub 2} particles caused by the sol-gel method used to prepare the SiC-TiO{sub 2} catalysts. TiO{sub 2} nanoparticles are well dispersed onto SiC surface allowing the transfer of electronic charges between SiC and TiO{sub 2} semiconductors, which avoid the fast recombination of the electron-hole pair during the photocatalytic process.

  9. White LED with High Package Extraction Efficiency

    International Nuclear Information System (INIS)

    The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/We using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat generated

  10. White LED with High Package Extraction Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Yi Zheng; Matthew Stough

    2008-09-30

    The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W{sub e} using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat

  11. Blue and UV Semiconductor Lasers

    International Nuclear Information System (INIS)

    Despite many technological difficulties the group III nitrides: GaN, AlN and InN and their alloys are primary candidates for electro-optical coherent light sources. In the recent years the research and technology of the nitride based continuous wave (CW) laser diodes (LDs) led to creation of blue-violet coherent light sources of power up to 200 mW. The progress has been attained by using various ways to attack the main obstacles in the technology of these devices such as insufficient size of high quality lattice matched substrates, low p-doping efficiency of Mg acceptor, poor contact to p-type semiconductor and low efficiency of radiative recombination. The two different approaches were used to overcome the substrate problem: hetero-epitaxy and homoepitaxy. Homoepitaxy used high pressure GaN high quality crystals. Heteroepitaxy used sapphire, SiC or GaAs substrates and very sophisticated techniques of reduction of the dislocation density. The low p-doping efficiency by using Mg acceptor is related to creation of Mg - H complexes due to hydrogen presence during the growth of laser diode quantum structures. In addition, Mg acceptor has low efficiency due to its high energy. High Mg concentrations can be obtained by using either MOCVD or ammonia source MBE growth. An alternative route is to use hydrogen-free plasma activated MBE (PA-MBE) method. The recent advances and the prospects of both approaches will be discussed. Solid AlGaInN solution offers a possibility to cover wide spectral range, starting from near UV to blue, green and red. Arsenide based laser diodes (LDs) are efficient coherent red light sources. Therefore, nitride based LDs are considered to be devices of choice for green, blue and UV spectral range. So far only blue and violet laser has been realized. The progress toward green and UV lasers is far less spectacular. The results in all these areas and future prospects will be discussed. (author)

  12. Optimum LED wavelength for underwater optical wireless communication at turbid water

    Science.gov (United States)

    Rosenkrantz, Etai; Arnon, Shlomi

    2014-10-01

    Underwater optical wireless communication is an emerging technology, which can provide high data rate. High data rate communication is required for applications such as underwater imaging, networks of sensors and swarms of underwater vehicles. These applications pursue an affordable light source, which can be obtained by light emitting diodes (LED). LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness based on off-the-shelf components such as blue and green light emitting diodes. In this paper we present our recent theoretical and experimental results in this field.

  13. 2014年诺贝尔物理学奖——蓝光LED的发明%2014 Nobel Prize in Physics——the Invention of Blue LED

    Institute of Scientific and Technical Information of China (English)

    李海

    2015-01-01

    2014年诺贝尔物理学奖授予日本科学家赤崎勇、天野浩和美籍日裔科学家中村修二,以表彰他们“发明的高效蓝色发光二极管(LED)带来了明亮而节能的白色光源”.为了更好地理解这一诺贝尔奖的意义,文章对LED的发光原理、发展历程及获奖者的主要贡献等作简要叙述.

  14. White-blue electroluminescence from a Si quantum dot hybrid light-emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Yunzi; Nishio, Kazuyuki [Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-hiroshima 739-8526 (Japan); Saitow, Ken-ichi, E-mail: saitow@hiroshima-u.ac.jp [Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-hiroshima 739-8526 (Japan); Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, Higashi-hiroshima 739-8526 (Japan)

    2015-05-18

    A silicon (Si) quantum dot (QD)-based hybrid inorganic/organic light-emitting diode (LED) was fabricated via solution processing. This device exhibited white-blue electroluminescence at a low applied voltage of 6 V, with 78% of the effective emission obtained from the Si QDs. This hybrid LED produced current and optical power densities 280 and 350 times greater than those previously reported for such device. The superior performance of this hybrid device was obtained by both the prepared Si QDs and the optimized layer structure and thereby improving carrier migration through the hybrid LED and carrier recombination in the homogeneous Si QD layer.

  15. Removal of blue indigo and cadmium present in aqueous solutions using a modified zeolitic material and an activated carbonaceous material; Remocion de azul indigo y cadmio presentes en soluciones acuosas empleando un material zeolitico modificado y un material carbonoso activado

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez S, E. E.

    2011-07-01

    In the last years the use of water has been increased substantially, it has been also altered its quality as a result of human activities such as mining, industrial activities and others. Water pollution caused by dyes and heavy metals has adverse effects on the environment, since both pollutants are very persisten even after conventional treatments. Denim blue and cadmium are not biodegradable. There is a growing interest in finding new, efficient and low cost alternative materials to remove such pollutants from the aqueous medium. The purpose of this work was to evaluate a modified zeolitic tuff and an activated carbonaceous material obtained from the pyrolysis of sewage sludge for the removal of denim blue and cadmium. The zeolitic material was modified with Na{sup +} and Fe{sup 3+} solutions to improve its sorption properties for the removal of cadmium and denim blue, respectively. Carbonaceous material was treated with 10% HCl solution to remove ashes. Both materials were characterized by scanning electron microscopy and elemental analysis (EDS), specific surface areas (Bet), thermogravimetric analysis, infrared spectroscopy and X-ray diffraction. Simultaneously, the denim blue dye was characterized by infrared spectroscopy and its pKa value was determined, these data allowed the determination of its chemical properties and its acid-base behavior in solution. In the content of this work the term indigo blue was changed by denim blue, as it corresponds to the commercial name of the dye. To assess the sorption capacity of sorbents, the sorption kinetics and sorption isotherms in batch system were determined; the results were fitted to mathematical models such as the pseudo-first order, pseudo second order and second order to describe the sorption kinetics and the Langmuir, Freundlich and Langmuir-Freundlich isotherms to describe sorption processes. The results show that the most efficient material to remove denim blue from aqueous solutions is the carbonaceous

  16. 红蓝光照射联合中药面膜维持治疗寻常性痤疮疗效观察%Efficacy and safety of blue and red LED phototherapy with Traditional Chinese Medicine mask in the maintenance treatment of acne vulgaris

    Institute of Scientific and Technical Information of China (English)

    高洁; 周李燕; 李超

    2012-01-01

    Objective To observe the effect and safety of maintenance treatment of acne vulgaris by using blue and red light emitting diode (LED) phototherapy combined with Traditional Chinese Medicine (TCM) mask. Methods After being treated with blue and red LED phototherapy with TCM mask for 8 times, 60 patients, who had got successfully improvement (more than 25%), were randomly divided into two groups. 30 patients in experimental group were treated with blue and red LED phototherapy with TCM mask once a week, while another 30 patients in control group were treated with adapalene gel every night. Results The assessment was evaluated alter a course of 16-week treatment. The total number of lesions was significantly decreased after maintenance treatment in both groups. In experimental group and control group, the reduction rate of total lesion counts were 64.20% and 64.69%, respectively, and the relapse rate was 6.67% and 7.14%, with no statistical significant difference between them (P>0.05). In experimental group, the rate of adverse reaction was obviously lower than that of control group (P<0.05). Conclusions The maintenance treatment with blue and red LED phototherapy with TCM mask once a week is effective for mild to moderate acne vulgaris, and its remarkable effect on decreasing relapse rate was similar to adapalene gel, and with few adverse reactions.%目的:观察红蓝光照射联合中药面膜维持治疗对预防和减少寻常性痤疮复发的疗效和安全性.方法:选择60例经红蓝光照射联合中药面膜治疗8次,并获临床有效(改善≥25%)的患者进行随机分组,治疗组30例,给予红蓝光照射联合中药面膜治疗,每周1次;对照组30例,采用每晚1次外用0.1%阿达帕林凝胶.结果:维持治疗16周后评价疗效,两组皮损总数均显著减少,治疗组皮损数减少了64.20%,对照组为64.69%;治疗组复发率为6.67%,对照组为7.14%,两组间比较差异无统计学意义(P>0.05).治疗组皮

  17. Therapeutic effect of blue and red LED phototherapy combined with traditional Chinese medical mask on acne vulgaris%窄谱红蓝光治疗仪联合中药面膜治疗寻常性痤疮疗效观察

    Institute of Scientific and Technical Information of China (English)

    刘乐; 李百灵; 陈文慧; 李伯埙

    2012-01-01

    Objective To evaluate the therapeutic effect of the blue and red light-emitting diode (LED) phototherapy combined with traditional Chinese medical mask for acne vulgaris.Methods 94 patients with acne vulgaris were randomly divided into three groups, all groups were treated with "Fu Fang Zhen Zhu An Chuang" tablets, treatment group (31cases)was treated with traditional Chinese medical mask combined with blue and red LED phototherapy control group 1 was treated with blue and red LED phototherapy,control group 2 was treated with traditional Chinese medical mask twice one week.The therapeutic effect of both three groups was determined four weeks later. Results The effective ratio of the treatment group (80.00%) were significantly higher than that in control groups (66.66%,64.51%),the difference between the three grups (x21=4.23,x22=4,85,P<0,01). Conclusion The blue and red LED phototherapy combined with traditional Chinese medical mask has a marked effect on inflammatory acne lesions and seems sufficient for the treatment of acne,the course of treatment could be shorted and adverse effects could be cut down.%目的:探讨蓝光(417nm)和红光(630nm)交替照射治疗轻中度痤疮的疗效.方法:将94例轻中度痤疮患者随机分为治疗组、对照1组和对照2组,共三组.治疗组采用红蓝光照射联合中药面膜;对照1组单用红蓝光照射;对照2组单用自制中药面膜敷脸,均2次/周,三组均外用痤疮洗剂,口服复方珍珠暗疮片,共4周.结果:治疗组总有效率为80.00%,对照1组、对照2组总有效率分别为66.66%、64.51%,治疗组总有效率与对照组比较差异有统计学意义(x21=4.23,x22=4.85,P<0.01),对照1组和对照2组比较差异无统计学意义(x2=12.34,P>0.05).结论:417nm蓝光和633nm红光联合中药面膜对轻中度痤疮的治疗安全、有效,可以缩短疗程,提高治愈率.

  18. Comparative study of kinetics of adsorption of methylene blue from aqueous solutions using cinnamon plant (Cinnamonum zeylanicum leaf powder and pineapple (Ananas comosus peel powder

    Directory of Open Access Journals (Sweden)

    Satish Dnyandeo Patil

    2012-07-01

    Full Text Available Batch adsorption of methylene blue (MB onto Cinnamon plant (Cinnamonum Zeylanicum leaf powder (CPLP and Pineapple (Ananas Comosus peel powder (PPP was investigated. Different parameters such as initial sorbate concentration, adsorbent dosage, pH, contact time, agitation speed, temperature and particle size. All isotherm models were found to be best fitting with high values of regression coefficient i.e. for Langmuir (R2 = 0.989 to 0.994 for CPLP and 0.993 to 0.995 for PPP, for Freundlich (R2 = 0.996 to 0.998 for CPLP and 0.995 for PPP and for Temkin (R2 = 0.983 to 0.995 for CPLP and 0.984 to 0.989 for PPP. The monolayer (maximum adsorption capacities (qm were found to be 250 and 333.333 mg/g for CPLP and PPP respectively. Lagergen pseudo -second order model best fits the kinetics of adsorption (R2 = 0.999 for CPLP and 1 for PPP. The amount of dye adsorbed at equilibrium qe(the obtained from Lagergen pseudo -second order model were found to be nearly same with the experimental data. Intra particle diffusion plot showed boundary layer effect and larger intercepts indicates greater contribution of surface sorption in rate determining step. Adsorption was found to be directly proportional to pH and temperature but inversely proportional to particle size. Thermodynamic analysis (∆G, ∆H and ∆S values showed adsorption was favourable, spontaneous, endothermic physisorption and increased disorder and randomness at the solid- solution interface of MB with the adsorbents. The forward rate constant was much higher than reverse rate constant suggesting dominance of rate of adsorption. PPP was found to be better adsorbent than CPLP.

  19. Blue enhanced light sources: opportunities and risks

    Science.gov (United States)

    Lang, Dieter

    2012-03-01

    Natural daylight is characterized by high proportions of blue light. By proof of a third type of photoreceptor in the human eye which is only sensitive in this spectral region and by subsequent studies it has become obvious that these blue proportions are essential for human health and well being. In various studies beneficial effects of indoor lighting with higher blue spectral proportions have been proven. On the other hand with increasing use of light sources having enhanced blue light for indoor illumination questions are arising about potential health risks attributed to blue light. Especially LED are showing distinct emission characteristics in the blue. Recently the French agency for food, environmental and occupational health & safety ANSES have raised the question on health issues related to LED light sources and have claimed to avoid use of LED for lighting in schools. In this paper parameters which are relevant for potential health risks will be shown and their contribution to risk factors will quantitatively be discussed. It will be shown how to differentiate between photometric parameters for assessment of beneficial as well as hazardous effects. Guidelines will be discussed how blue enhanced light sources can be used in applications to optimally support human health and well being and simultaneously avoid any risks attributed to blue light by a proper design of lighting parameters. In the conclusion it will be shown that no inherent health risks are related to LED lighting with a proper lighting design.

  20. The Clinical Efficacy of Blue Red Led Phototherapy Combined with Jinhua Xiaocuo Pills and Chloramphenicol Tincture on the Treatment of Acne Vulgaris%红蓝光治疗仪联合金花消痤丸及氯霉素酊治疗寻常痤疮疗效观察

    Institute of Scientific and Technical Information of China (English)

    张玉红

    2013-01-01

    Objective To observe the clinical efficacy of blue and red led phototherapy combined with jinhua xiaocuo pills and chloramphenicol tincture on the treatment of patients with acne vulgaris. Methods Patients were randomly divided into two groups,60 patients of treatment group were treated by red blue phototherapy combined with jinhua xiaocuo pills and chloramphenicol tincture, 60 patients of control group were treated with jinhua xiaocuo pills and chloramphenicol tincture. Acne was assessed at baseline and 4 weeks later. Results The effective rate in treating group was 91.67% and control group was 65.00% (P <0. 05) ;Two subjects reported side effects of the light treatment in the form of mild facial erythema, itching and scaling. Conclusion Blue and red led phototherapy combined with jinhua xiaocuo pills and chlorampenicol tincture on the treatment of acne is superior to jinhua xiaocuo pills and chlorampenicol tincture.%目的 观察红蓝光治疗仪联合金花消痤丸及氯霉素酊治疗寻常痤疮的临床疗效.方法 将入选患者随机分成两组,治疗组60例用红蓝光照射联合口服金花消痤丸剂外用氯霉素酊治疗,对照组60例仅口服金花消痤丸剂外用氯霉素酊治疗,方法同治疗组,疗程均为4周.结果 治疗结束后,治疗组有效率91.67%,对照组65.00%,差异有统计学意义(P<0.05);治疗组有2例经红蓝光照射后面部皮肤出现轻度潮红、瘙瘁和脱屑.结论 红蓝光治疗仪联合口服金花消痤丸及外用氯霉素酊治疗痤疮起效快、有效率高、复发率低、值得临床选用.

  1. Comparison Between Clinical Effect of LED Cold Light With the Conventional Blue Phototherapy in Treatment of Neonatal Jaundice%LED冷光源与常规蓝光光疗治疗新生儿黄疸的临床效果对比

    Institute of Scientific and Technical Information of China (English)

    樊宏燕

    2016-01-01

    Objective To compare the effcacy of conventional blue light and cold light source in the treatment of neonatal jaundice. Methods 60 cases of neonatal jaundice from January 2014 to October 2015 in our hospital were randomly divided into control group and experimental group, two groups were used conventional cold light blue and blue light therapy, observed the efficacy.ResultsBefore treatment, the results of the two groups showed no difference in serum total bilirubin (P>0.05), 48 h and 96 h decreased significantly after treatment, the degree of decline in the experimental group were more obvious than in the control group (P<0.05), during the period of treatment, the rate of adverse reactions in the experimental group was signiifcantly lower than the control group (P<0.05). Conclusion Neonatal jaundice using LED cold light blue light therapy has signiifcant effect and safety.%目的:对比新生儿黄疸采取LED冷光源与常规蓝光治疗的疗效。方法选取60例于2014年1月~2015年10月我院接受新生儿黄疸患者,将其随机分为对照组与实验组,两组分别采用常规蓝光及冷光源蓝光光疗,观察两组疗效。结果治疗前,两组血清总胆红素比较差异无统计学意义(P>0.05),治疗后48 h及96 h明显下降,实验组下降程度较对照组显著(P<0.05);治疗期间,不良反应情况上,实验组较对照组低(P<0.05)。结论新生儿黄疸采用LED冷光源蓝光光疗,疗效显著,且安全、节能。

  2. LED-LED portable oxygen gas sensor

    OpenAIRE

    Perez de Vargas Sansalvador, Isabel; Fay, Cormac; Fernandez-Ramos, M.D.; Diamond, Dermot; Benito-Lopez, Fernando; Capitan-Vallvey, L.F.

    2012-01-01

    A portable instrument for oxygen determination, based on the quenching of phosphorescent octaethylporphyrin by gaseous O2, has been developed using the fluorimetric paired emitter–detector diode technique (FPEDD). The instrument configuration used consists of two light emitting diodes (LEDs) facing each other including an interchangeable support containing a phosphorescent membrane in between, in which one of the LEDs is used as the light source (emitter LED) and the other working in reverse...

  3. Blue Nile

    OpenAIRE

    Ramos, Manuel João

    2000-01-01

    The Blue Nile, whose source lies in highland Ethiopia, is known as “Al-Bahr al- Azraq” in Arabic, and as “Abbay” in Amharic. Along with the Atbara, it contributes more than 80 per cent of the Nile’s total water supply, the remainder coming mainly from the White Nile that stretches down to the Great Lakes plateau in Central Africa.

  4. Advanced poly-LED displays

    Science.gov (United States)

    Childs, Mark; Nisato, Giovanni; Fish, D.; Giraldo, Andrea; Jenkins, A. J.; Johnson, Mark T.

    2003-05-01

    Philips have been actively developing polymer OLED (poly-LED) displays as a future display technology. Their emissive nature leads to a very attractive visual appearance, with wide viewing angle, high brightness and fast response speed. Whilst the first generation of poly-LED displays are likely to be passive-matrix driven, power reduction and resolution increase will lead to the use of active-matrix poly-LED displays. Philips Research have designed, fabricated and characterized five different designs of active-matrix polymer-LED display. Each of the five displays makes use of a distinct pixel programming- or pixel drive-technique, including current programming, threshold voltage measurement and photodiode feedback. It will be shown that hte simplest voltage-programmed current-source pixel suffers from potentially unacceptable brightness non-uniformity, and that advanced pixel circuits can provide a solution to this. Optical-feedback pixel circuits will be discussed, showing that they can be used to improve uniformity and compensate for image burn-in due to polymer-LED material degradation, improving display lifetime. Philips research has also been active in developing technologies required to implement poly-LED displays on flexible substrates, including materials, processing and testing methods. The fabrication of flexible passive-matrix poly-LED displays will be presented, as well as the ongoing work to assess the suitability of processing flexible next-generation poly-LED displays.

  5. Research on the Photocatalytic Degradability of Methylene Blue Solution by Photocatalysis Bamboo Charcoal Fiber Knitted Fabric%光催化竹炭纤维针织物光催化降解亚甲基蓝的研究

    Institute of Scientific and Technical Information of China (English)

    周荣稳; 王秋美; 刘淑英; 邹志伟; 徐雪梅

    2011-01-01

    In order to develop new functional fabrics, the photocatalytic degradabilltys of methylene blue solution by photocatalysis bamboo charcoal fiber knitted fabric was researched. The relationships were analyzed between the removal rate and the response time, the initial concentration and pH value of methylene blue solution, the distance between the ultraviolet light centre and liquid level. The results were as follows : it indicated an obvious photocatalytic degradation effect of methylene blue solution by photocatalysis bamboo charcoal fiber knitted fabric under UV-irradiation. And the removal rate could reach 67. 02%. When the initial concentration of methylene blue solution is lower, the pH value of methylene blue solution is higher,and the distance between light centre and liquid level is shorter, the effect was better. It indicated that the photocatalysis bamboo charcoal fiber knitted fabric could be used as filter materials and wastewater treatment materials.%为了开发新型功能型织物,研究了光催化竹炭纤维织物对亚甲基蓝溶液的光催化降解效果,分析了反应时间、亚甲基蓝溶液的初始浓度、pH值、光源中心与液面间距离等因素对亚甲基蓝溶液光催化降解效果的影响.结果表明,光催化竹炭纤维针织物在紫外线的照射下对亚甲基蓝溶液产生明显的降解效果,其去除率可达67.02%;亚甲基蓝溶液的初始浓度越低,降解效果越好;亚甲基蓝溶液的初始pH值越高,降解效果越好;光源中心与液面间距较小时织物的光催化降解效果较好.因此,光催化竹炭纤维针织物可用作过滤、污水处理材料等.

  6. EFFICIENCY EVALUATION OF NaY ZEOLITE AND TiO2/NaY ZEOLITE IN REMOVAL OF METHYLENE BLUE DYE FROM AQUEOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    M. Zendehdel

    2011-09-01

    Full Text Available In this study titanium dioxide cluster was incorporated onto NaY zeolite and characterized with X-Ray diffractometer and X-ray spectroscopy. These composites have many advantages such as high stability and high porosity. The adsorption behavior of methylene blue was investigated for NaY zeolite and TiO2/NaY zeolite. The efficiency of time, pH, temperature and initial concentration of methylene blue (MB on removal effect of methylene blue was investigated by UV-Vis spectroscopy. And, the optimum conditions were determined 8h time, basic pH and high initial concentrations of methylene blue and absorbent. With increasing of temperature, the removal efficiency of NaY zeolite and TiO2/NaY increased. Results showed that 92% and 85% of methylene blue was absorbed by synthesized NaY zeolite and TiO2/zeolite, respectively. Adsorption isotherm as studied by fitting data to Langmuir and Freundlich isotherms models, showed monolayer adsorption and Langmuir equilibrium model to be more relevant.

  7. Multicolor, High Efficiency, Nanotextured LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Jung Han; Arto Nurmikko

    2011-09-30

    We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and green for Solid State Lighting applications. Accomplishments in the duration of the contract period include (i) heteroepitaxy of nitrogen-polar LEDs on sapphire, (ii) heteroepitaxy of semipolar (11{bar 2}2) green LEDs on sapphire, (iii) synthesis of quantum-dot loaded nanoporous GaN that emits white light without phosphor conversion, (iv) demonstration of the highest quality semipolar (11{bar 2}2) GaN on sapphire using orientation-controlled epitaxy, (v) synthesis of nanoscale GaN and InGaN medium, and (vi) development of a novel liftoff process for manufacturing GaN thin-film vertical LEDs. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

  8. 石英砂负载氧化铁吸附去除溶液中亚甲蓝的研究%Removal of methylene blue in solution by iron-oxide coated quartz sand

    Institute of Scientific and Technical Information of China (English)

    宣寒; 谢发之; 王颖; 曹田; 陈艳; 陈方平

    2013-01-01

    Using quartz sand as raw material,iron oxide coated quartz sand(IOCS) has been prepared.IOCS performance and the effect of adsorption conditions on the adsorption capacity for methylene blue and the regeneration of adsorptive column are investigated.The adsorption course has been studied kinetically.The results show that the IOCS prepared by high temperature sintering method has better adsorption capacity for methylene blue.The optimal conditions for IOCS to adsorb the methylene blue in solution are as follows:pH is 13.5,mass concentration of methylene blue about 6 mg/L,temperature 293 K,and adsorptive sample flow velocity 4 BV/h.The curve of adsorptive kinetics of methylene blue in solution can be fitted with Weber-Morris curve.Langmuir and Freundlich adsorption isotherm equations can well describe the adsorption course of methylene blue in solution by IOCS.The regeneration efficacy of IOCS adsorptive column by using 0.01 mol/L of HCl is pretty good.%以石英砂为原料制得石英砂负载氧化铁(IOCS),考察了IOCS的性能、吸附条件对IOCS吸附亚甲蓝效果的影响及吸附柱的再生,并对吸附过程进行了动力学研究.结果表明,采用高温烧结法制备的IOCS吸附亚甲蓝效果较好;IOCS对溶液中亚甲蓝吸附的适宜条件:pH为13.5,亚甲蓝质量浓度约为6mg/L,温度为293 K,上样液吸附流速为4 BV/h; IOCS对溶液中亚甲蓝的吸附动力学曲线可以用Weber-Morris曲线来拟合;Langmuir吸附等温方程和Freundlich方程都能较好地描述IOCS对溶液中亚甲蓝的吸附过程;0.01 mol/L的HCl对IOCS吸附柱的再生效果较好.

  9. LED white lights with high CRI and high luminous efficacy

    Science.gov (United States)

    He, Guoxing; Zheng, Lihong; Yan, Huafeng

    2010-11-01

    The models for spectra of a phosphor-coated white (p-W) LED and a white light LED cluster are developed based on the principle of additive color mixture. The simulation results show that p-W LEDs consisting of a blue chip (450nm), green phosphor (507 nm), yellow phosphor (580 nm) and red phosphor (655 nm) could realize color rendering indices (CRIs) above 97.7 and special CRIs of R1 to R14 above 91.1, but luminous efficacies of radiation (LERs) below 250.3 lm/W, that white/red clusters consisting of red LEDs and p-W LEDs with a blue chip (450nm), green (507 nm) and yellow (580 nm) phosphors could realize given color temperature white light with CRIs above 97.9 and special CRIs of R1 to R14 above 89.6, as well as LERs above 296.3 lm/W, and that a neutral-white /red//blue cluster consisting of blue LEDs (465 nm), red LEDs (628 nm) and neutral-white LEDs with a blue chip (452 nm), green (530 nm) and yellow (586 nm) phosphors could realize CCT tunable white lights with CRIs above 97.9 and special CRIs of R1 to R14 above 89.6, as well as LER above 296.3 lm/W.

  10. Posthuman blues

    CERN Document Server

    Tonnies, Mac

    2013-01-01

    Posthuman Blues, Vol. I is first volume of the edited version of the popular weblog maintained by author Mac Tonnies from 2003 until his tragic death in 2009. Tonnies' blog was a pastiche of his original fiction, reflections on his day-to-day life, trenchant observations of current events, and thoughts on an eclectic range of material he culled from the Internet. What resulted was a remarkably broad portrait of a thoughtful man and the complex times in which he lived, rendered with intellige...

  11. The Impact of Soil Erosion in the Upper Blue Nile on Downstream Reservoir Sedimentation

    OpenAIRE

    Ali, Y.S.A.

    2014-01-01

    Population growth in the Blue Nile Basin has led to fast land-use changes from forest to agricultural land, which resulted in speeding up the soil erosion processes producing highly negative impacts on the local soil fertility and agricultural productivity. The eroded sediment is transported downstream by water and sinks in the lower basin where it significantly reduces reservoir storage and irrigation canals capacity. The only effective solution to mitigate the sedimentation problem is to li...

  12. Acne Vulgaris Treated with Integrative Chinese Medicine Therapies Combined with Blue and Red LED Phototherapy: A Clinical Observation of 30 Cases%中医综合疗法联合红蓝光治疗寻常型痤疮30例

    Institute of Scientific and Technical Information of China (English)

    孙捷; 杜长明; 刘明珠

    2011-01-01

    目的 观察中医综合疗法联合红蓝光治疗寻常型痤疮的临床疗效.方法 将54例寻常型痤疮患者随机分为治疗组和对照组,对照组24例患者口服一清胶囊和外搽0.1%迪维霜,治疗组30例患者口服清热利湿化痰、凉血活血的中药汤剂,外用中药熏药和面膜,及采用红蓝光照射.2周为1个疗程.观察并比较治疗前后皮疹总评分和中医证候总评分的变化,以及两组痤疮愈显率和中医证候愈显率.结果 治疗后两组皮疹总评分和中医证候总评分均显著下降(P<0.01),治疗组皮疹总评分显著低于对照组(P<0.05);治疗组痤疮愈显率和中医证候愈显率显著高于对照组(P<0.05,或P<0.01).结论 中医综合疗法联合红蓝光疗法能显著改善寻常型痤疮患者的皮损情况及湿热证候.%Objective To observe the therapeutic effects of integrative Chinese medicine treatments combined with blue and red LED phototherapy in treating acne vulgaris. Methods Fifty-four patients with acne vulgaris were randomized into control group and treatment group. Twenty-four patients in the control group were treated with oral administration of Yiqing Capsules, a patent traditional Chinese medicine (TCM) , and external application of 0. 1% Diweishuang Emulsifiable Paste; while 30 patients in the treatment group were treated with TCM decoction for clearing heat, removing dampness, resolving phlegm,cooling blood, and activating blood circulation, and external application of TCM fumigation and TCM mask, as well as red and blue LED phototherapy. Before and after treatment, some indicators, including the total scores of rashes, and TCM syndrome as well as the recovery plus excellent efficacy rates of acne,and TCM syndrome, were observed and compared between the two groups. Results After treatment, the scores of rashes, and TCM syndrome were significantly decreased in the two groups compared with those before treatment (P<0. 01) ; furthermore, the scores of

  13. High Performance Green LEDs by Homoepitaxial

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Christian; Schubert, E Fred

    2009-11-22

    This work's objective was the development of processes to double or triple the light output power from green and deep green (525 - 555 nm) AlGaInN light emitting diode (LED) dies within 3 years in reference to the Lumileds Luxeon II. The project paid particular effort to all aspects of the internal generation efficiency of light. LEDs in this spectral region show the highest potential for significant performance boosts and enable the realization of phosphor-free white LEDs comprised by red-green-blue LED modules. Such modules will perform at and outperform the efficacy target projections for white-light LED systems in the Department of Energy's accelerated roadmap of the SSL initiative.

  14. White LEDs with limit luminous efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Lisitsyn, V. M.; Stepanov, S. A., E-mail: stepanovsa@tpu.ru; Yangyang, Ju [National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Lukash, V. S. [JSC Research Institute of Semiconductor Devices, 99a Krasnoarmeyskaja St., Tomsk, 634050 (Russian Federation)

    2016-01-15

    In most promising widespread gallium nitride based LEDs emission is generated in the blue spectral region with a maximum at about 450 nm which is converted to visible light with the desired spectrum by means of phosphor. The thermal energy in the conversion is determined by the difference in the energies of excitation and emission quanta and the phosphor quantum yield. Heat losses manifest themselves as decrease in the luminous efficacy. LED heating significantly reduces its efficiency and life. In addition, while heating, the emission generation output and the efficiency of the emission conversion decrease. Therefore, the reduction of the energy losses caused by heating is crucial for LED development. In this paper, heat losses in phosphor-converted LEDs (hereinafter chips) during spectrum conversion are estimated. The limit values of the luminous efficacy for white LEDs are evaluated.

  15. Adsorption of cationic dye methylene blue onto activated carbon obtained from horse chestnut kernel

    Directory of Open Access Journals (Sweden)

    Momčilović Milan Z.

    2011-01-01

    Full Text Available Horse chestnut kernel was used as the precursor for the preparation of powdered activated carbon using phosphoric acid as the activating agent. Batch adsorption experiments for the adsorption of cationic dye methylene blue from aqueous solutions were carried out using the obtained carbon as adsorbent. Equilibrium and kinetic experiments were conducted. The equilibrium data were fitted with the Langmuir, Freundlich and Temkin theoretical isotherm models. The best results was obtained in the case of Langmuir model, which indicates that monolayer adsorption occurs on finite number of the active adsorption sites on the carbon surface. The kinetic data were fitted with pseudo-first, pseudo-second, Elovich and interparticle diffusion model. Pseudo-second order model and Elovich model showed the best results of the kinetic data. The increasing of the solution pH led to a higher uptake of methylene blue due to the fact that competitive adsorption of methylene blue cation and proton exists in acidic solutions. The adsorption capacity for methylene blue in equilibrium study was significant (168.93 mg g-1. Comparison of the adsorption capacities of methylene blue onto activated carbons derived from various alternative precursors proves chestnut kernel to be efficient and low-cost material which could be substantially deployed in the future.

  16. Alcian blue-stained particles in a eutrophic lake

    DEFF Research Database (Denmark)

    Worm, J.; Søndergaard, Morten

    1998-01-01

    We used a neutral solution of Alcian Blue to stain transparent particles in eutrophic Lake Frederiksborg Slotss0, Denmark. Alcian Blue-stained particles (ABSP) appeared to be similar to the so-called transparent exopolymer particles (TEP) identified with an acidic solution of Alcian Blue. Our...

  17. LED Color Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-01

    Color quality is an important consideration when evaluating LED-based products for general illumination. This fact sheet reviews the basics regarding light and color and summarizes the most important color issues related to white-light LED systems.

  18. Sequential study on reactive blue 29 dye removal from aqueous solution by peroxy acid and single wall carbon nanotubes: experiment and theory

    OpenAIRE

    Jahangiri-Rad Mahsa; Nadafi Kazem; Mesdaghinia Alireza; Nabizadeh Ramin; Younesian Masood; Rafiee Mohammad

    2013-01-01

    Abstract The majority of anthraquinone dye released to the environment come from antrapogenic sources. Several techniques are available for dyes' removal. In this study removal of reactive blue 29 (RB29) by an advanced oxidation process sequenced with single wall carbon nanotubes was investigated. Advanced oxidation process was optimized over a period of 60 minutes by changing the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2% -56.4% of rea...

  19. Comparative Study for Adsorptive Removal of Coralene Blue BGFS Dye from Aqueous Solution by MgO and Fe2O3 as an Adsorbent

    OpenAIRE

    Parth Desai,; Kartik Gonawala

    2014-01-01

    Textile industries represent biggest impact on the environment due to high water consumption and waste water discharge as government control water pollution by setting strength regulation for waste water discharge, removal of color from waste water becomes more and more essential and attractive. Adsorption technology is very efficient in treatment of textile effluent. In this paper comparison of adsorption phenomena of textile dye Anthraquinone blue onto two different adsorben...

  20. LEDs for greenhouse lighting

    OpenAIRE

    Nederhoff, E.M.

    2010-01-01

    Light Emitting Diodes (LED's) are a promising technology for greenhouse lighting with their efficiency to activate plant photosynthesis potentially higher in red LEDs than in HPS lamps. Due to their particular light colour, LEDs can initiate special effects in plants or steer plant processes and plant balance

  1. LEDs for greenhouse lighting

    NARCIS (Netherlands)

    Nederhoff, E.M.

    2010-01-01

    Light Emitting Diodes (LED's) are a promising technology for greenhouse lighting with their efficiency to activate plant photosynthesis potentially higher in red LEDs than in HPS lamps. Due to their particular light colour, LEDs can initiate special effects in plants or steer plant processes and pla

  2. Chitin-Prussian blue sponges for Cs(I) recovery: From synthesis to application in the treatment of accidental dumping of metal-bearing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, C. [Ecole des mines d' Alès, Centre des Matériaux des Mines d' Alès, C2MA/MPA/BCI, 6 avenue de Clavières, F-30319 Alès Cedex (France); Commissariat à l' Energie Atomique, CEA Marcoule, DEN/DTCD/SPDE/LPSD,BP 17171, F-30207 Bagnols sur Cèze (France); Barré, Y. [Commissariat à l' Energie Atomique, CEA Marcoule, DEN/DTCD/SPDE/LPSD,BP 17171, F-30207 Bagnols sur Cèze (France); Vincent, T. [Ecole des mines d' Alès, Centre des Matériaux des Mines d' Alès, C2MA/MPA/BCI, 6 avenue de Clavières, F-30319 Alès Cedex (France); Taulemesse, J.-M. [Ecole des mines d' Alès, Center des Matériaux des Mines d' Alès, 6 avenue de Clavières, F-30319 Alès Cedex (France); Robitzer, M. [Institut Charles Gerhardt – UMR5253, CNRS-UM2-ENSCM-UM1, ICGM-MACS-R2M2, 8 rue de l' Ecole Normale, F-34296 Montpellier Cedex 05 (France); Guibal, E., E-mail: Eric.Guibal@mines-ales.fr [Ecole des mines d' Alès, Centre des Matériaux des Mines d' Alès, C2MA/MPA/BCI, 6 avenue de Clavières, F-30319 Alès Cedex (France)

    2015-04-28

    Highlights: • Prussian blue microparticles incorporated in chitin sponges. • Efficient Cs(I) sorption after water absorption by dry hybrid sponge. • Water draining after sorption for metal confinement and water decontamination. • High decontamination factors and distribution coefficients for Cs(I) and {sup 137}Cs(I). • Effect of freezing conditions on porous structure and textural characterization. - Abstract: Prussian blue (i.e., iron[III] hexacyanoferrate[II], PB) has been synthesized by reaction of iron(III) chloride with potassium hexacyanoferrate and further immobilized in chitosan sponge (cellulose fibers were added in some samples to evaluate their impact on mechanical resistance). The composite was finally re-acetylated to produce a chitin-PB sponge. Experimental conditions such as the freezing temperature, the content of PB, the concentration of the biopolymer and the presence of cellulose fibers have been varied in order to evaluate their effect on the porous structure of the sponge, its water absorption properties and finally its use for cesium(I) recovery. The concept developed with this system consists in the absorption of contaminated water by the composite sponge, the in situ binding of target metal on Prussian blue load and the centrifugation of the material to remove treated water from soaked sponge. This material is supposed to be useful for the fast treatment of accidental dumping of Cs-contaminated water.

  3. Chitin-Prussian blue sponges for Cs(I) recovery: From synthesis to application in the treatment of accidental dumping of metal-bearing solutions

    International Nuclear Information System (INIS)

    Highlights: • Prussian blue microparticles incorporated in chitin sponges. • Efficient Cs(I) sorption after water absorption by dry hybrid sponge. • Water draining after sorption for metal confinement and water decontamination. • High decontamination factors and distribution coefficients for Cs(I) and 137Cs(I). • Effect of freezing conditions on porous structure and textural characterization. - Abstract: Prussian blue (i.e., iron[III] hexacyanoferrate[II], PB) has been synthesized by reaction of iron(III) chloride with potassium hexacyanoferrate and further immobilized in chitosan sponge (cellulose fibers were added in some samples to evaluate their impact on mechanical resistance). The composite was finally re-acetylated to produce a chitin-PB sponge. Experimental conditions such as the freezing temperature, the content of PB, the concentration of the biopolymer and the presence of cellulose fibers have been varied in order to evaluate their effect on the porous structure of the sponge, its water absorption properties and finally its use for cesium(I) recovery. The concept developed with this system consists in the absorption of contaminated water by the composite sponge, the in situ binding of target metal on Prussian blue load and the centrifugation of the material to remove treated water from soaked sponge. This material is supposed to be useful for the fast treatment of accidental dumping of Cs-contaminated water

  4. The Discussion of LED Display’s Light Pollution and Technical Solution%户外全彩LED显示屏光污染防治及技术解决方案探讨

    Institute of Scientific and Technical Information of China (English)

    屠孟龙

    2014-01-01

    In this paper, the light pollution of LED outdoor display is discussed. The main light pollution’s references limits , including light invasion, the glare, the LED display’s brightness and sky glow, is proposed. The LED package level solution of the display light pollution has been proposed. Within the valid visible range, the light energy is concentrated here, help to reduce the display power consumption. Within the invalid visible range, try to reduce the light energy distribution and light pollution. By comparison the data of the reduction of light pollution, LED package level solutions can reduce the brightness in the invalid visible range of 10%to 50%of the light pollution.%本论文对LED户外显示屏的光污染问题进行了探讨,对LED显示屏的主要光污染,包括光入侵、眩光、显示屏亮度、夜空辉光等光污染,参照国际照明委员会(CIE)与上海市的限制标准,提出了LED显示屏的光污染的参考限制参数。针对显示屏的光污染,提出了器件级的解决方案。在有效可视范围内,光能量集中分布,有利于降低显示屏功耗,在无效可视范围内,尽量降低光能量分布,减少光污染。经过实测数据的对比,这个器件级的降低光污染解决方案,能有效降低无效可视亮度范围内10%~50%的光污染。

  5. Warm white LED light by frequency down-conversion of mixed yellow and red Lumogen

    Science.gov (United States)

    Mosca, Mauro; Caruso, Fulvio; Zambito, Leandro; Seminara, Biagio; Macaluso, Roberto; Calı, Claudio; Feltin, Eric

    2013-05-01

    This work reports on the benefits and promising opportunities offered by white LED hybrid technology, based on a mixing perylene-based dyes in order to obtain a warm white light for frequency-down conversion. In a standard Ce:YAG-based white LED, the white light appears cold due to the weakness of red wavelength components in the emission spectrum. In order to obtain a warmer white, one possible solution is to add a red phosphor to the yellow one to move the chromatic coordinates properly, though the luminous efficiency drastically decreases due to the increased light absorption of the coating layer. It is generally believed that the low efficiency of warm white LEDs is the main issue today for LED-based lighting. Using photoluminescence of Lumogen® F Yellow 083, a perylene-based polymer dye commercialized by BASF, and adding a small quantity of another perylene-based dye, Lumogen® F Red 305 (BASF), we obtained high-efficiency warm white LEDs by yellow and red conversion from a standard 450 nm GaN/InGaN royal blue LED. Different weight proportions of dyes were dissolved in solutions with equal amounts of poly-methyl-methacrylate (PMMA) in ethyl acetate, then the LEDs were dip-coated in each solution and optically characterized. Record values of 8.03 lm of luminous flux and 116.11 lm/W of optical efficiency were achieved. Finally, the effects of both driving current, and pump wavelength on LED performances - such as chromatic coordinates, correlated color temperature, color rendering index (CRI), and optical efficiency - were investigated.

  6. Retinal damage induced by commercial light emitting diodes (LEDs).

    Science.gov (United States)

    Jaadane, Imene; Boulenguez, Pierre; Chahory, Sabine; Carré, Samuel; Savoldelli, Michèle; Jonet, Laurent; Behar-Cohen, Francine; Martinsons, Christophe; Torriglia, Alicia

    2015-07-01

    Spectra of "white LEDs" are characterized by an intense emission in the blue region of the visible spectrum, absent in daylight spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina. The aim of our study was to elucidate the role of blue light from LEDs in retinal damage. Commercially available white LEDs and four different blue LEDs (507, 473, 467, and 449nm) were used for exposure experiments on Wistar rats. Immunohistochemical stain, transmission electron microscopy, and Western blot were used to exam the retinas. We evaluated LED-induced retinal cell damage by studying oxidative stress, stress response pathways, and the identification of cell death pathways. LED light caused a state of suffering of the retina with oxidative damage and retinal injury. We observed a loss of photoreceptors and the activation of caspase-independent apoptosis, necroptosis, and necrosis. A wavelength dependence of the effects was observed. Phototoxicity of LEDs on the retina is characterized by a strong damage of photoreceptors and by the induction of necrosis. PMID:25863264

  7. Use of agricultural waste sugar beet pulp for the removal of Gemazol turquoise blue-G reactive dye from aqueous solution

    International Nuclear Information System (INIS)

    The potential use of dried sugar beet pulp, an agricultural solid waste by-product, as an biosorbent for Gemazol turquoise blue-G, a copper-pthalocyanine reactive dye commonly used in dyeing of cotton, was investigated in the present study. Batch adsorption studies were carried out to examine the influence of various parameters such as initial pH, temperature and initial dye concentration. The results indicated that adsorption was strongly pH-dependent and slightly temperature-dependent. At 800 mg l-1 initial Gemazol turquoise blue-G concentration, dried sugar beet pulp exhibited the highest Gemazol turquoise blue-G uptake capacity of 234.8 mg g-1 at 25 deg. C and at an initial pH value of 2.0. The Freundlich, Langmuir, Redlich-Peterson and Langmuir-Freundlich, the two and three parameters adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated depending on temperature. Both the Langmuir and Redlich-Peterson models were applicable for describing the dye biosorption by dried sugar beet pulp in the concentration (100-800 mg l-1) and temperature (25-45 deg. C) ranges studied. Simple mass transfer and kinetic models were applied to the experimental data to examine the mechanisms of biosorption and potential rate controlling steps such as external mass transfer, intraparticle diffusion and biosorption process. The sorption process was found to be controlled by both surface and pore diffusion with surface diffusion at the earlier stages followed by pore diffusion at the later stages. Pseudo first-order, pseudo second-order and saturation type kinetic models described the biosorption kinetics accurately at all concentrations and temperatures studied. The thermodynamic analysis indicated that the sorption process was exothermic and the biosorption of dye on dried sugar beet pulp might be physical in nature

  8. A LED Flasher for TUNKA experiment

    CERN Document Server

    Lubsandorzhiev, B K; Shaibonov, B A J; Vyatchin, Y E; Zablotsky, A Z

    2007-01-01

    A LED flasher has been developed for TUNKA-133 EAS Cherenkov detector. A blue ultra bright InGaN LED is used as a light source in the flasher. The flasher's driver is based on a fast discharge of a small capacitor via a complementary pair of fast RF transistors. The light yield of the flasher is adjusted in the wide range of from 0 to up to 10**9 photons per pulse. The results of studies of the flasher's amplitude and timing parameters and their stability are presented.

  9. Comparative study of kinetics of adsorption of methylene blue from aqueous solutions using cinnamon plant (Cinnamonum zeylanicum) leaf powder and pineapple (Ananas comosus) peel powder

    OpenAIRE

    Satish Dnyandeo Patil; S. Renukdas; N. T. Patel

    2012-01-01

    Batch adsorption of methylene blue (MB) onto Cinnamon plant (Cinnamonum Zeylanicum) leaf powder (CPLP) and Pineapple (Ananas Comosus) peel powder (PPP) was investigated. Different parameters such as initial sorbate concentration, adsorbent dosage, pH, contact time, agitation speed, temperature and particle size. All isotherm models were found to be best fitting with high values of regression coefficient i.e. for Langmuir (R2 = 0.989 to 0.994 for CPLP and 0.993 to 0.995 for PPP), for Freundlic...

  10. Synthesis and Characterization of High Efficiency and Stable Spherical Ag3PO4 Visible Light Photocatalyst for the Degradation of Methylene Blue Solutions

    Directory of Open Access Journals (Sweden)

    Liqin Qin

    2015-01-01

    Full Text Available A facile method for the synthesis of Ag3PO4 visible light photocatalyst has been developed to improve the photocatalytic activity and stability. The as-prepared samples are investigated by X-ray powder diffraction, scanning electron microscopy, infrared spectroscopy, photoluminescence (PL spectroscopy, and UV-Vis diffuse reflectance spectroscopy techniques. The results reveal that the prepared Ag3PO4 has cube structure with a band gap of 2.26 eV. The as-prepared samples show higher photocatalytic activity for methylene blue (MB degradation than that of N-TiO2 under visible light irradiation.

  11. Assessing the colour quality of LED sources

    DEFF Research Database (Denmark)

    Jost-Boissard, S.; Avouac, P.; Fontoynont, Marc

    2015-01-01

    sources and especially some LEDs. In this paper, several aspects of perceived colour quality are investigated using a side-by-side paired comparison method, and the following criteria: naturalness of fruits and vegetables, colourfulness of the Macbeth Color Checker chart, visual appreciation...... but also with a preference index or a memory index calculated without blue and purple hues. A very low correlation was found between appreciation and naturalness indicating that colour quality needs more than one metric to describe subjective aspects....

  12. LED-roulette: LED's vervangen balletje

    OpenAIRE

    Goossens, P

    2007-01-01

    Iedereen waagt wel eens een gokje, in een loterij of misschien ook in een casino. Wie droomt er immers niet van om op een gemakkelijke manier rijk te worden? Met de hier beschreven LED-roulette valt weliswaar weinig te winnen, maar het is wel een uitstekende manier om het roulettespel thuis te beoefenen op een eerlijke manier. Je kunt er namelijk niet mee valsspelen, de microcontroller die de LED’s aanstuurt is, onomkoopbaar.

  13. LED-valaisimien kuormitustaulukointi

    OpenAIRE

    Reinilä, Toni

    2015-01-01

    Opinnäytetyössä perehdyttiin virran käyttäytymiseen LED-valaisimen käynnistyessä. Työssä syvennyttiin LED-valaisimien teoriaan sekä teholähteiden ominaisuuksiin. Työ tehtiin Winled Oy:n pyynnöstä, koska yrityksellä oli tarve LED-valaisimien kuormitustaulukolle. Opinnäytetyön tavoite oli tuottaa lisää tietoa LED-valaisimista ja niiden ominaisuuksista. LED-valaisimen tiedetään ottavan suuria virtoja käynnistyessään. Työn tarkoitus oli laatia LED-valaisimien käynnistysvirroista kuormitustaulukko...

  14. Research of the influence of radiation of light from emitting diodes in Fricke solution doped with photosensibilizers of low cost

    International Nuclear Information System (INIS)

    This study aims to verify the behavior of FAM dosimeters (Fricke solution doped with methylene blue), FVM (Fricke solution doped with malachite green) and FAT (Fricke solution doped with toluidine blue) after irradiation with LED. Photodynamic therapy (PDT), the newest form of treatment for some types of cancer, is the association of a photosensitizing agent to a light source, in order to induce cancer cell death. PDT does not have a dosimetry and is usually performed with lasers, and photosensitizers imported and expensive. The red and blue were chosen for the experiments. The solution was prepared and Fricke Fricke doped solutions were prepared by adding 100 μg/mL of the photosensitizers. Subsequently, ethanol was added to the dosimeters yielding the FATA , FAME and FVMA. Doped solutions were transferred to test tubes and irradiated in acrylic phantoms. The solutions were irradiated their optical densities measured in a UV - VIS spectrophotometer. Thus, it was found that after irradiation, the dosimeters showed linear behavior showing good correlation coefficients for the samples irradiated with LEDs. The FAME when irradiated with blue light, also showed a linear correlation. However , for FVMA behavior was presented an equation of 2nd degree. Concluding that the LED irradiated dosimeters have shown sensitivity to light so that they can be used for dosimetry in PDT, and the results also show that PDT can be realized with LED photosensitizers and low cost

  15. Led-valaistus liikerakennuksessa

    OpenAIRE

    Heikkilä, Juho

    2014-01-01

    Tässä insinöörityössä tutkittiin led-valaistuksen tuomia mahdollisuuksia liikerakennuksien valaistuksessa. Aihetta pohdittiin suunnittelijan näkökulmasta ja painotus oli liikerakennuksen eri tilojen valaistusmahdollisuuksissa. Liikerakennuksissa on tarvetta yleisvalaistukselle, kohdevalaistukselle, sosiaalitilojen sekä pysäköintipaikkojen valaistukselle. Näille tiloille pyrittiin suunnittelemaan optimaalinen valaistus led-valaisimilla. Led-valaisimet ovat korvaamassa valaisimia kaikilla näill...

  16. Phototherapy with blue and green mixed-light is as effective against unconjugated jaundice as blue light and reduces oxidative stress in the Gunn rat model.

    OpenAIRE

    Uchida, Yumiko; Morimoto, Yukihiro; Uchiike, Takao; Kamamoto, Tomoyuki :4/0000339; Hayashi, Tamaki; Arai, Ikuyo; Nishikubo, Toshiya; Takahashi, Yukihiro

    2015-01-01

    OBJECTIVE:Phototherapy using blue light-emitting diodes (LED) is effective against neonatal jaundice. However, green light phototherapy also reduces unconjugated jaundice. We aimed to determine whether mixed blue and green light can relieve jaundice with minimal oxidative stress as effectively as either blue or green light alone in a rat model.METHODS:Gunn rats were exposed to phototherapy with blue (420-520 nm), filtered blue (FB; 440-520 nm without

  17. Facile fabrication of highly efficient AgI/ZnO heterojunction and its application of methylene blue and rhodamine B solutions degradation under natural sunlight

    International Nuclear Information System (INIS)

    Highlights: • A high-efficiency natural sunlight driven AgI/ZnO photocatalysts have been first prepared. • Our method is a simple, environment-friendly and cost-effective process. • The possible photocatalytic mechanism of AgI/ZnO was proposed. • AgI/ZnO exhibits higher efficiency for the degradation of methylene blue and rhodamine B under natural sunlight than a 500 W Xe lamp. - Abstract: The AgI/ZnO heterojunction was successfully synthesized by in situ deposition method and was found to be a natural sunlight driven photocatalyst. The photocatalytic efficiency of AgI/ZnO was evaluated by the degradation of rhodamine B under visible light irradiation. The influence of various operational parameters such as the effect of loading amount, catalyst dosage and initial RhB concentration on the photodegradation was investigated in detail and the results were discussed. The results indicated that the AgI/ZnO composites displayed much higher photocatalytic performances over ZnO as well as AgI. Moreover, the catalyst obviously showed higher efficiency for the degradation of methylene blue and rhodamine B under natural sunlight than a 500 W Xe lamp, and nearly 100% of dyes were degraded only in 120 min under the optimum conditions. At last, the quenching effects of different scavengers suggested that the reactive • OH and h+ play the major role in the RhB degradation

  18. TRUE COLORS: LEDS AND THE RELATIONSHIP BETWEEN CCT, CRI, OPTICAL SAFETY, MATERIAL DEGRADATION, AND PHOTOBIOLOGICAL STIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P.

    2014-08-30

    This document analyzes the optical, material, and photobiological hazards of LED light sources compared to conventional light sources. It documents that LEDs generally produce the same amount of blue light, which is the primary contributor to the risks, as other sources at the same CCT. Duv may have some effect on the amount of blue light, but CRI does not.

  19. Dansk LED - Museumsbelysning

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Dam-Hansen, Carsten; Thorseth, Anders;

    Projektet har til formål at anvende dansk forskning inden for optik og lys til at realisere innovative energieffektive LED lyssystemer til museumsbranchen.......Projektet har til formål at anvende dansk forskning inden for optik og lys til at realisere innovative energieffektive LED lyssystemer til museumsbranchen....

  20. LED lighting. Special issue; Led-verlichting. Themanummer

    Energy Technology Data Exchange (ETDEWEB)

    Adams, T. [Spectrum Advies en Design, Putten (Netherlands); Derksen, A. [Isso, Rotterdam (Netherlands); Van Mil, R.; Van Lieshout, M.; Vollebregt, R.

    2010-10-15

    In four articles in this issue the focus on illuminance by LEDs: interview with the director of Velux Netherlands, expert in skylights and daylight solutions; the influence of lighting on the cognitive performance of students; the use of energy efficient, dynamic lighting; the Isso publication (number 90) 'Energy-efficient lighting and around buildings'; and the promise of the OLED flat skylight. [Dutch] In vier artikelen wordt in deze aflevering aandacht besteed aan verlichting d.m.v. LEDs: (interview met de directeur van Velux Nederland, specialist in dakramen en daglichtoplossingen; de invloed van verlichting op leerprestaties van scholieren; het gebruik van energie efficiente, dynamisch verlichtingssystemen; de Isso-publicatie (nummer 90) 'Energie-efficiente verlichting in en rondom gebouwen; en de belofte van de platvallichtbron Oled.

  1. High quality GaN-based LED epitaxial layers grown in a homemade MOCVD system

    Science.gov (United States)

    Haibo, Yin; Xiaoliang, Wang; Junxue, Ran; Guoxin, Hu; Lu, Zhang; Hongling, Xiao; Jing, Li; Jinmin, Li

    2011-03-01

    A homemade 7 × 2 inch MOCVD system is presented. With this system, high quality GaN epitaxial layers, InGaN/GaN multi-quantum wells and blue LED structural epitaxial layers have been successfully grown. The non-uniformity of undoped GaN epitaxial layers is as low as 2.86%. Using the LED structural epitaxial layers, blue LED chips with area of 350 × 350 μm2 were fabricated. Under 20 mA injection current, the optical output power of the blue LED is 8.62 mW.

  2. High quality GaN-based LED epitaxial layers grown in a homemade MOCVD system

    Institute of Scientific and Technical Information of China (English)

    Yin Haibo; Wang Xiaoliang; Ran Junxue; Hu Guoxin; Zhang Lu; Xiao Hongling; Li Jing; Li Jinmin

    2011-01-01

    A homemade 7 × 2 inch MOCVD system is presented.With this system,high quality GaN epitaxial layers,InGaN/GaN multi-quantum wells and blue LED structural epitaxial layers have been successfully grown.The non-uniformity of undoped GaN epitaxial layers is as low as 2.86%.Using the LED structural epitaxial layers,blue LED chips with area of 350 × 350μm2 were fabricated.Under 20 mA injection current,the optical output power of the blue LED is 8.62 mW.

  3. High quality GaN-based LED epitaxial layers grown in a homemade MOCVD system

    Energy Technology Data Exchange (ETDEWEB)

    Yin Haibo; Wang Xiaoliang; Ran Junxue; Hu Guoxin; Zhang Lu; Xiao Hongling; Li Jing; Li Jinmin, E-mail: hbyin@semi.ac.cn [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2011-03-15

    A homemade 7 x 2 inch MOCVD system is presented. With this system, high quality GaN epitaxial layers, InGaN/GaN multi-quantum wells and blue LED structural epitaxial layers have been successfully grown. The non-uniformity of undoped GaN epitaxial layers is as low as 2.86%. Using the LED structural epitaxial layers, blue LED chips with area of 350 x 350 {mu}m{sup 2} were fabricated. Under 20 mA injection current, the optical output power of the blue LED is 8.62 mW. (semiconductor materials)

  4. LED-kasvivalaisin

    OpenAIRE

    Anttila, Toni

    2008-01-01

    LED-teknologian käyttö kasvihuonevalaistuksessa tulee lisääntymään. LED-valaistuksen etuja ovat mahdollisuudet energian säästöön, kasvatustilan vähentäminen ja mahdollisuudet kontrolloida kasvien kasvua. Tulevaisuudessa erityisvalaistuksen määrä kasvien kasvatuksessa tulee lisääntymään. Tässä työssä suunniteltiin ja rakennettiin LED-kasvivalaisin. Työssä käytiin läpi teoreettinen pohja kasvivalotukselle ja esiteltiin suunnittelun ja rakentamisen eri vaiheet ongelmineen ja erityispiirteine...

  5. Why Do Proteins Glow Blue?

    CERN Document Server

    Sarkar, Sohini; Hazra, Partha; Mandal, Pankaj

    2014-01-01

    Recent literatures reported blue-green emission from amyloid fibril as exclusive signature of fibril formation. This unusual visible luminescence is regularly used to monitor fibril growth. Blue-green emission has also been observed in crystalline protein and in solution. However, the origin of this emission is not known exactly. Our spectroscopic study of serum proteins reveals that the blue-green emission is a property of protein monomer. Evidences suggest that semiconductor-like band structure of proteins with the optical band-gap in the visible region is possibly the origin of this phenomenon. We show here that the band structure of proteins is primarily the result of electron delocalization through the peptide chain, rather than through the hydrogen bond network in secondary structure.

  6. Spectroradiometry for LED characterization

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten

    Radiospectroscopy is the absolute measurement of electromagnetic radiation within a specific wavelength range. For characterization of LED components, light sources and lamps we are interested in absolute measurement of the spectral power distribution, SPD, in the visible and near infrared region....... Using integrating spheres for light collection setups for absolute total spectral flux is realized at the LED Light Lab at DTU Fotonik, Risø Campus. From these, both total radiant and luminous flux is determined and through electrical power measurement also the efficiency is determined. From the SPD...... colorimetric quantities like color coordinates, color temperature and color rendering indices are calculated. The facilities and special issues concerning LED measurements compared to traditional light sources are explained and examples from the “LED lighting quality program”, a project supported by the Danish...

  7. Prospects for LED lighting.

    Energy Technology Data Exchange (ETDEWEB)

    Tsao, Jeffrey Yeenien; Gee, James Martin; Simmons, Jerry Alvon

    2003-08-01

    Solid-state lighting using light-emitting diodes (LEDs) has the potential to reduce energy consumption for lighting by 50% while revolutionizing the way we illuminate our homes, work places, and public spaces. Nevertheless, substantial technical challenges remain in order for solid-state lighting to significantly displace the well-developed conventional lighting technologies. We review the potential of LED solid-state lighting to meet the long-term cost goals.

  8. RS-232 Led Board

    OpenAIRE

    Tskhvaradze, Vladimir

    2007-01-01

    This article demonstrates how to develop a Microchip PIC16F84 based device that supports RS-232 interface with PC. Circuit (LED Board) design and software development will be discussed. PicBasic Pro Compiler from microEngineering Labs, Inc. is used for PIC programming. Development of LED Board Control Console using C/C++ is also briefly discussed. The project requires basic work experience with Microchip PICs, serial communication and programming.

  9. LED facades in urbarchitecture

    OpenAIRE

    Cekić Nikola; Dačić Miloš; Kostić Aleksandra

    2012-01-01

    Rapid development of electronic technologies at the beginning of this century resulted in intensive changes in urbarchitectonic formation of façade planes and physical structures. Advent of LED lights and LED panels made possible that the physical structures in urban agglomerations worldwide, old or new, have opened a new chapter for strategic urbarchitectonic design and different cultural illumination diversity of houses in space. The user relationship towards activities in physical en...

  10. Surface plasmon enhanced LED

    OpenAIRE

    Vučković, Jelena; Lončar, Marko; Painter, Oskar; Scherer, Axel

    2000-01-01

    Summary form only given. We designed and fabricated an LED based on a thin semiconductor membrane (λ/2) with silver mirrors. A large spontaneous emission enhancement and a high modulation speed are obtainable due to the strong localization of the electromagnetic field in the microcavity. The coupling to surface plasmon modes which are subsequently scattered out by means of a grating is used to improve the extraction efficiency of the LED. The bottom mirror is thick and unpatterned. The top mi...

  11. Blue ocean leadership.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2014-05-01

    Ten years ago, two INSEAD professors broke ground by introducing "blue ocean strategy," a new model for discovering uncontested markets that are ripe for growth. In this article, they apply their concepts and tools to what is perhaps the greatest challenge of leadership: closing the gulf between the potential and the realized talent and energy of employees. Research indicates that this gulf is vast: According to Gallup, 70% of workers are disengaged from their jobs. If companies could find a way to convert them into engaged employees, the results could be transformative. The trouble is, managers lack a clear understanding of what changes they could make to bring out the best in everyone. Here, Kim and Mauborgne offer a solution to that problem: a systematic approach to uncovering, at each level of the organization, which leadership acts and activities will inspire employees to give their all, and a process for getting managers throughout the company to start doing them. Blue ocean leadership works because the managers' "customers"-that is, the people managers oversee and report to-are involved in identifying what's effective and what isn't. Moreover, the approach doesn't require leaders to alter who they are, just to undertake a different set of tasks. And that kind of change is much easier to implement and track than changes to values and mind-sets. PMID:24956870

  12. Effect of operational parameters on the decolorization of C.I. Reactive Blue 19 in aqueous solution by ozone-enhanced electrocoagulation

    International Nuclear Information System (INIS)

    The aim of this paper was to investigate the efficiency of the ozone-enhanced electrocoagulation (EC) process in the decolorization of C.I. Reactive Blue 19 in water using iron electrodes. We determined the effects of various operating parameters such as initial pH, initial dye concentration, current density, salt concentration, temperature, ozone flow rate, and distance between electrodes on decolorization efficiency in a laboratory-scale reactor. Increasing the initial dye concentration decreased the decolorization efficiency, whereas increasing the distance between electrodes increased it. The other operating factors had both positive and negative effects. With an initial pH of 10.0, an initial dye concentration of 100 mg/L, current density of 10 mA/cm2, salt concentration of 3000 mg/L, temperature of 30 deg. C, ozone flow rate of 20 mL/min, and distance between electrodes of 3 cm, over 96% of the color was removed after 10 min. As a consequence, removal of total organic carbon (TOC) was over 80%

  13. Effect of operational parameters on the decolorization of C.I. Reactive Blue 19 in aqueous solution by ozone-enhanced electrocoagulation

    Energy Technology Data Exchange (ETDEWEB)

    Song Shuang; Yao Jie [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); He Zhiqiao [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)], E-mail: zqhe@zjut.edu.cn; Qiu Jianping; Chen Jianmeng [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

    2008-03-21

    The aim of this paper was to investigate the efficiency of the ozone-enhanced electrocoagulation (EC) process in the decolorization of C.I. Reactive Blue 19 in water using iron electrodes. We determined the effects of various operating parameters such as initial pH, initial dye concentration, current density, salt concentration, temperature, ozone flow rate, and distance between electrodes on decolorization efficiency in a laboratory-scale reactor. Increasing the initial dye concentration decreased the decolorization efficiency, whereas increasing the distance between electrodes increased it. The other operating factors had both positive and negative effects. With an initial pH of 10.0, an initial dye concentration of 100 mg/L, current density of 10 mA/cm{sup 2}, salt concentration of 3000 mg/L, temperature of 30 deg. C, ozone flow rate of 20 mL/min, and distance between electrodes of 3 cm, over 96% of the color was removed after 10 min. As a consequence, removal of total organic carbon (TOC) was over 80%.

  14. LED Irradiation of a Photocatalyst for Benzene, Toluene, Ethyl Benzene,and Xylene Decomposition%LED Irradiation of a Photocatalyst for Benzene,Toluene,Ethyl Benzene,and Xylene Decomposition

    Institute of Scientific and Technical Information of China (English)

    JO Wan-Kuen; KANG Hyun-Jung

    2012-01-01

    Studies on the use of gas phase applications of light emitting diodes (LEDs) in photocatalysis are scarce although their photocatalytic decomposition kinetics of environmental pollutants are likely different from those in aqueous solutions.The present study evaluated the use of chips of visible light LEDs to irradiate nitrogen doped titania (N-TiO2) prepared by hydrolysis to decompose gaseous benzene,toluene,ethyl benzene,m-xylene,p-xylene,and o-xylene.Photocatalysts calcined at different temperatures were characterized by various analytical instruments.The degradation efficiency of benzene was close to zero for all conditions.For the other compounds,a conventional 8 W daylight lamp/N-TiO2 unit gave a higher photocatalytic degradation efficiency as compared with that of visible-LED/N-TiO2 units.However,the ratios of degradation efficiency to electric power consumption were higher for the photocatalytic units that used two types of visible-LED lamps (blue and white LEDs).The highest degradation efficiency was observed with the use of a calcination temperature of 350 ℃.The average degradation efficiencies for toluene,ethyl benzene,m-xylene,p-xylene,and o-xylene were 35%,68%,94%,and 93%,respectively.The use of blue-and white-LEDs,high light intensity,and low initial concentrations gave high photocatalytic activities for the photocatalytic units using visible-LEDs.The morphological and optical properties of the photocatalysts were correlated to explain the dependence of photocatalytic activity on calcination temperature.The results suggest that visible-LEDs are energy efficient light source for photocatalytic gas phase applications,but the activity depends on the operational conditions.

  15. Blue cures blue but be cautious

    Directory of Open Access Journals (Sweden)

    Pranav Sikka

    2011-01-01

    Full Text Available Methemoglobinemia is a disorder characterized by the presence of >1% methemoglobin (metHb in the blood. Spontaneous formation of methemoglobin is normally counteracted by protective enzyme systems, for example, nicotinamide adenine dinucleotide phosphate (NADPH methemoglobin reductase. Methemoglobinemia is treated with supplemental oxygen and methylene blue (1-2 mg/kg administered slow intravenously, which acts by providing an artificial electron acceptor for NADPH methemoglobin reductase. But known or suspected glucose-6-phosphate dehydrogenase (G6PD deficiency is a relative contraindication to the use of methylene blue because G6PD is the key enzyme in the formation of NADPH through pentose phosphate pathway and G6PD-deficient individuals generate insufficient NADPH to efficiently reduce methylene blue to leukomethylene blue, which is necessary for the activation of the NADPH-dependent methemoglobin reductase system. So, we should be careful using methylene blue in methemoglobinemia patient before G6PD levels.

  16. Light Emitting Diodes (LEDs)

    Science.gov (United States)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique, called Photodynamic Therapy, requires the surgeon to use tiny, pinhead-size Light Emitting Diodes (LEDs) (a source that releases long wavelengths of light ) to activate light-sensitive, tumor-treating drugs. 'A young woman operated on in May 1999 has fully recovered with no complications and no evidence of the tumor coming back,' said Dr. Harry Whelan, a pediatric neurologist at the Medical Hospital of Wisconsin in Milwaukee. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can be used for hours at a time while still remaining cool to the touch. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The LEDs, developed and managed by NASA's Marshall Space Flight Center, have been used on seven Space Shuttle flights inside the Microgravity Astroculture Facility. This technology has also been successfully used to further commercial research in crop growth.

  17. Light Emitting Diode (LED)

    Science.gov (United States)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique called photodynamic therapy, requires the surgeon to use tiny pinhead-size Light Emitting Diodes (LEDs) (a source releasing long wavelengths of light) to activate light-sensitive, tumor-treating drugs. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can also be used for hours at a time while still remaining cool to the touch. The LED probe consists of 144 tiny pinhead-size diodes, is 9-inches long, and about one-half-inch in diameter. The small balloon aids in even distribution of the light source. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The probe was developed for photodynamic cancer therapy by the Marshall Space Flight Center under a NASA Small Business Innovative Research program grant.

  18. Semiconducting polymer LEDs

    Directory of Open Access Journals (Sweden)

    David Braun

    2002-06-01

    The field of semiconducting polymers has its root in the 1977 discovery of the semiconducting properties of polyacetylene1. This breakthrough earned Alan Heeger, Alan MacDiarmid, and Hideki Shirakawa the 2000 Nobel Prize in Chemistry for ‘the discovery and development of conductive polymers’2–5. Other review articles capture how more than two decades of developments in the physical and chemical understanding of these novel materials has led to new device applications as active and passive electronic and optoelectronic devices ranging from diodes and transistors to polymer LEDs, photodiodes, lasers, and solar cells6–11. Much interest in plastic devices derives from the opportunities to use clever control of polymer structure combined with relatively economical polymer synthesis and processing techniques to obtain simultaneous control over electronic, optical, chemical, and mechanical features5. This article focuses on the advances leading to polymer LEDs12–14.

  19. Led-sukellusvalaisin

    OpenAIRE

    Saarelainen, Mikko

    2012-01-01

    Opinnäytetyön aiheena on LED ja sen käyttö sukellusvalaisimissa. Työn tarkoitus oli tutkia miten LED toimii ja miten se soveltuu käytettäväksi sukellusvalaisimessa, sekä syventää omaa tietoutta valosta, mitä se on ja miten sitä mitataan. Työssä käydään läpi LEDin ominaisuuksia ja miten se eroaa muista sukellusvalaisimissa käytetyistä lampuista. Työ on toteutettu tutustumalla LEDiin ja valoon käyttämällä erilaisia lähteitä ja päivittämällä nykyinen sukellusvalaisimeni LED-sukellusvalaisime...

  20. Led-tievalaistus

    OpenAIRE

    Parviainen, Samuli

    2015-01-01

    Opinnäytetyön tavoitteena oli tehdä selvitystyö led-tievalaistuksesta. Työssä perehdytään Tiehallinnon vaatimuksiin tievalaistuksesta ja tievalaistuksesta. Työssä keskitytään tarkemmin led-valaistukseen ja sen hyötyihin. Työssä tarkastellaan myös Euroopan Unionin direktiivejä ja säädöksiä, jotka liittyvät valaistukseen ja energian säätämiseen julkisilla paikolla.

  1. LED-tekniikka elokuvavalaisussa

    OpenAIRE

    Laurila, Mika

    2016-01-01

    Opinnäytetyön tavoitteena oli luoda suomenkielinen katsaus led-tekniikan kehityksen tilanteesta vuonna 2016. Työtä varten haastateltiin viittä suomalaista elokuvavalaisijaa, ja siihen kerättiin kirjallista materiaalia sekä elokuva-alan kirjallisuudesta että internetistä. Työllä haluttiin tuoda esille led-tekniikan tuomia hyötyjä elokuvavalaisussa sekä toisaalta haluttiin paneutua myös ledien aiheuttamiin haasteisiin. Haastatteluiden pohjalta huomattiin ledien teknisen tason nousseen jo s...

  2. LED-valot rakentamisessa

    OpenAIRE

    Jokinen, Matti

    2011-01-01

    Tämä sähkövoimatekniikan opinnäytetyö tehtiin Rejlers Oy:lle.Vuonna 1942 perustettu Suomen Rejlers on osa pohjoismaista Rejlerkoncernen yhtiötä. Yhtiö tarjoaa suunnittelua, konsultointia ja turnkey-toimituksia teollisuuden, energian, rakentamisen ja kiinteistöjen sekä infran toimialoilla Suomessa, Ruotsissa, Virossa ja Norjassa. Opinnäytetyön tavoitteena oli tuoda esille LED-tekniikalla toteutettuja valojen käyttömahdollisuuksia rakentamisessa. Työssä tutustuttiin LED-valojen ominaisuuks...

  3. Latest Developments in LED Standards

    OpenAIRE

    Yurtseven, M. Berker; Onaygil, Sermin

    2015-01-01

    The LED light sources can be stated as the most promising technology for the last decade from the lighting technology point of view. In order to compare LED chips and LED products from different manufacturers and achieve reproducible results, all of the manufacturers shall measure their LEDs or LED based products using same methodology. In this study, it is aimed to explain measurement and performance standards for LED chips and LED based Solid State Lighting products.

  4. Thermal management for LED applications

    CERN Document Server

    Poppe, András

    2014-01-01

    Thermal Management for LED Applications provides state-of-the-art information on recent developments in thermal management as it relates to LEDs and LED-based systems and their applications. Coverage begins with an overview of the basics of thermal management including thermal design for LEDs, thermal characterization and testing of LEDs, and issues related to failure mechanisms and reliability and performance in harsh environments. Advances and recent developments in thermal management round out the book with discussions on advances in TIMs (thermal interface materials) for LED applications, advances in forced convection cooling of LEDs, and advances in heat sinks for LED assemblies. This book also: Presents a comprehensive overview of the basics of thermal management as it relates to LEDs and LED-based systems Discusses both design and thermal management considerations when manufacturing LEDs and LED-based systems Covers reliability and performance of LEDs in harsh environments Has a hands-on applications a...

  5. Promoting student led education

    OpenAIRE

    Kotecha, Meena

    2011-01-01

    This paper will discuss the encouraging outcomes of a small scale study in which students were encouraged to actively contribute to various aspects of their education. It will share an innovative Student Led Education Initiative that emerged by extending the author’s teaching practice. First year undergraduate students were encouraged to actively contribute to various aspects of their education. The rationale behind this was to inspire students to lead the way in their education. ...

  6. Student-led education

    OpenAIRE

    Kotecha, Meena

    2012-01-01

    The author has co-presented this presentation with her students to discuss the findings of her individual initiative in which she has discussed how she encouraged her undergraduates to actively contribute to various aspects of their education. She has shared an innovative Student Led Education Initiative that emerged by extending her teaching practice. The rationale behind this was to inspire students to lead the way in their education. This was the author's response to The Higher Education W...

  7. Smart LED lighting for major reductions in power and energy use for plant lighting in space

    Science.gov (United States)

    Poulet, Lucie

    Launching or resupplying food, oxygen, and water into space for long-duration, crewed missions to distant destinations, such as Mars, is currently impossible. Bioregenerative life-support systems under development worldwide involving photoautotrophic organisms offer a solution to the food dilemma. However, using traditional Earth-based lighting methods, growth of food crops consumes copious energy, and since sunlight will not always be available at different space destinations, efficient electric lighting solutions are badly needed to reduce the Equivalent System Mass (ESM) of life-support infrastructure to be launched and transported to future space destinations with sustainable human habitats. The scope of the present study was to demonstrate that using LEDs coupled to plant detection, and optimizing spectral and irradiance parameters of LED light, the model crop lettuce (Lactuca sativa L. cv. Waldmann's Green) can be grown with significantly lower electrical energy for plant lighting than using traditional lighting sources. Initial experiments aimed at adapting and troubleshooting a first-generation "smart" plant-detection system coupled to LED arrays resulted in optimizing the detection process for plant position and size to the limits of its current design. Lettuce crops were grown hydroponically in a growth chamber, where temperature, relative humidity, and CO2 level are controlled. Optimal irradiance and red/blue ratio of LED lighting were determined for plant growth during both lag and exponential phases of crop growth. Under optimizing conditions, the efficiency of the automatic detection system was integrated with LED switching and compared to a system in which all LEDs were energized throughout a crop-production cycle. At the end of each cropping cycle, plant fresh and dry weights and leaf area were measured and correlated with the amount of electrical energy (kWh) consumed. Preliminary results indicated that lettuce plants grown under optimizing

  8. Research of the influence of radiation of light from emitting diodes in Fricke solution doped with photosensibilizers of low cost; Averiguacao da influencia da radiacao de diodos emissores de luz na solucao Fricke dopada com fotossensibilizadores de baixo custo

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Mayara G.O. de; Lima, Vanessa L. de; Nascimento, Rizia K. do; Santos, Patricia N.C. dos; Souza, Vivianne L.B. de, E-mail: mayaradgf@hotmail.com, E-mail: lemos.nessa@yahoo.com.br, E-mail: riziakeila@hotmail.com, E-mail: patty_fofa007@hotmail.com, E-mail: vlsouza@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-11-01

    This study aims to verify the behavior of FAM dosimeters (Fricke solution doped with methylene blue), FVM (Fricke solution doped with malachite green) and FAT (Fricke solution doped with toluidine blue) after irradiation with LED. Photodynamic therapy (PDT), the newest form of treatment for some types of cancer, is the association of a photosensitizing agent to a light source, in order to induce cancer cell death. PDT does not have a dosimetry and is usually performed with lasers, and photosensitizers imported and expensive. The red and blue were chosen for the experiments. The solution was prepared and Fricke Fricke doped solutions were prepared by adding 100 {mu}g/mL of the photosensitizers. Subsequently, ethanol was added to the dosimeters yielding the FATA , FAME and FVMA. Doped solutions were transferred to test tubes and irradiated in acrylic phantoms. The solutions were irradiated their optical densities measured in a UV - VIS spectrophotometer. Thus, it was found that after irradiation, the dosimeters showed linear behavior showing good correlation coefficients for the samples irradiated with LEDs. The FAME when irradiated with blue light, also showed a linear correlation. However , for FVMA behavior was presented an equation of 2nd degree. Concluding that the LED irradiated dosimeters have shown sensitivity to light so that they can be used for dosimetry in PDT, and the results also show that PDT can be realized with LED photosensitizers and low cost.

  9. NAPAJALNIK SVETIL LED

    OpenAIRE

    Grešak, Aleksander

    2013-01-01

    Namen Diplomskega dela je bilo izdelati napajalnik svetil LED. Predstavljene so teoretične podlage delovanja napajalnika, njegova izdelava, ter opravljene določene meritve. Napajalnik deluje na principu stikalnega usmernika, ki izmenično napetost pri visoki frekvenci pretvarja v enosmerno. Uporabili smo pretvornik navzdol, ker je želena izhodna napetost nižja od vhodne. Prednosti stikalnega napajalnika so boljši izkoristek vezja, vezje je manjše in posledično tudi lažje.

  10. LED-valaistus kasvihuoneisiin

    OpenAIRE

    Anderson, Janne

    2010-01-01

    Valo on kasvien tärkein energian ja informaation lähde. Kasvihuoneviljelyssä voidaan keinovalaistuksen avulla pidentää kasvukautta sekä tehostaa tuotantoa. Keinovalaistuksen vaatima sähköenergia on merkittävä kuluerä suomalaisessa kasvihuoneviljelyssä. Tässä työssä selvitettiin LED - valaistuksen soveltuvuutta kasvihuoneviljelyyn sekä ledien tuomia etuja nykyisiin järjestelmiin verrattuna. Ledien avulla on mahdollista päästä merkittäviin säästöihin energiankulutuksessa sekä parantaa sado...

  11. Vilkkuva led-uistin

    OpenAIRE

    Korkala, Mika

    2016-01-01

    Opinnäytetyön tarkoituksena oli kehittää oman idean pohjalta vilkkuva led-uistin ja selvittää idean mahdollinen laillisuus ja patentoitavuus. Opinnäytetyöhön tutkittiin kalastusta, siinä käytettäviä apuvälineitä, kalojen värinäköä sekä Suomen kalastuslakia. Opinnäytetyötä varten tutkittiin myös patentointiprosesseja ja patentointiin liittyviä muita asioita, voimassa olevia ja jo vanhentuneita patentteja aiheeseen liittyen. Tutkimusmateriaalina käytettiin saatavissa olevia tutkimuksia,...

  12. Blue light emitting diodes for optical stimulation of quartz in retrospective dosimetry and dating

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Duller, G.A.T.; Murray, A.S.; Banerjee, D.

    Recently developed blue light emitting diodes (LEDs) for the optical stimulation of quartz for use in routine optically stimulated luminescence (OSL) dating and retrospective dosimetry have been tested. For similar power densities, it was found that the higher energy light provided by the blue LEDs...

  13. Luminous Intensity of an LED as a Function of Input Power

    OpenAIRE

    Sean King

    2008-01-01

    When current passes through a light-emitting diode (LED), the LED emits an incoherent narrow spectrum of light. The relationship between the input power and the light intensity of an LED is studied in this research. Voltage ranging from 2 to 4 Volts was applied to a blue LED. The voltage across the LED, current through the LED and intensity of the light emitted by the LED were measured. For voltages ranging from 2.4 to 3.5 V, light intensity was found to be linearly related to both the curren...

  14. High-power LEDs for plant cultivation

    Science.gov (United States)

    Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

    2004-10-01

    We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

  15. Spectral Design Flexibility of LED Brings Better life

    DEFF Research Database (Denmark)

    Ou, Haiyan; Corell, Dennis Dan; Ou, Yiyu;

    2012-01-01

    white light using different color mixing schemes. The spectral design flexibility of white LED light sources will promote them for novel applications to improve the life quality of human beings. As an initial exploration to make use of the spectral design flexibility, we present an example: 'no blue......Light-emitting diodes (LEDs) are penetrating into the huge market of general lighting because they are energy saving and environmentally friendly. The big advantage of LED light sources, compared to traditional incandescent lamps and fluorescent light tubes, is the flexible spectral design to make...

  16. Decolorization of C.I. Acid Blue 9 solution by UV/Nano-TiO2, Fenton, Fenton-like, electro-Fenton and electrocoagulation processes: A comparative study

    International Nuclear Information System (INIS)

    This study makes a comparison between UV/Nano-TiO2, Fenton, Fenton-like, electro-Fenton (EF) and electrocoagulation (EC) treatment methods to investigate the removal of C.I. Acid Blue 9 (AB9), which was chosen as the model organic contaminant. Results indicated that the decolorization efficiency was in order of Fenton > EC > UV/Nano-TiO2 > Fenton-like > EF. Desired concentrations of Fe2+ and H2O2 for the abatement of AB9 in the Fenton-based processes were found to be 10-4 M and 2 x 10-3 M, respectively. In the case of UV/Nano-TiO2 process, we have studied the influence of the basic photocatalytic parameters such as the irradiation time, pH of the solution and amount of TiO2 nanoparticles on the photocatalytic decolorization efficiency of AB9. Accordingly, it could be stated that the complete removal of color, after selecting desired operational parameters could be achieved in a relatively short time, about 25 min. Our results also revealed that the most effective decomposition of AB9 was observed with 150 mg/l of TiO2 nanoparticles in acidic condition. The effect of operational parameters including current density, initial pH and time of electrolysis were studied in electrocoagulation process. The results indicated that for a solution of 20 mg/l AB9, almost 98% color were removed, when the pH was about 6, the time of electrolysis was 8 min and the current density was approximately 25 A/m2 in electrocoagulation process

  17. Decolorization of C.I. Acid Blue 9 solution by UV/Nano-TiO{sub 2}, Fenton, Fenton-like, electro-Fenton and electrocoagulation processes: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Khataee, A.R. [Water and Wastewater Treatment Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: a_khataee@tabrizu.ac.ir; Vatanpour, V. [Water and Wastewater Treatment Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: vahidvatanpoor@yahoo.com; Amani Ghadim, A.R. [Water and Wastewater Treatment Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: a.r_amani@yahoo.com

    2009-01-30

    This study makes a comparison between UV/Nano-TiO{sub 2}, Fenton, Fenton-like, electro-Fenton (EF) and electrocoagulation (EC) treatment methods to investigate the removal of C.I. Acid Blue 9 (AB9), which was chosen as the model organic contaminant. Results indicated that the decolorization efficiency was in order of Fenton > EC > UV/Nano-TiO{sub 2} > Fenton-like > EF. Desired concentrations of Fe{sup 2+} and H{sub 2}O{sub 2} for the abatement of AB9 in the Fenton-based processes were found to be 10{sup -4} M and 2 x 10{sup -3} M, respectively. In the case of UV/Nano-TiO{sub 2} process, we have studied the influence of the basic photocatalytic parameters such as the irradiation time, pH of the solution and amount of TiO{sub 2} nanoparticles on the photocatalytic decolorization efficiency of AB9. Accordingly, it could be stated that the complete removal of color, after selecting desired operational parameters could be achieved in a relatively short time, about 25 min. Our results also revealed that the most effective decomposition of AB9 was observed with 150 mg/l of TiO{sub 2} nanoparticles in acidic condition. The effect of operational parameters including current density, initial pH and time of electrolysis were studied in electrocoagulation process. The results indicated that for a solution of 20 mg/l AB9, almost 98% color were removed, when the pH was about 6, the time of electrolysis was 8 min and the current density was approximately 25 A/m{sup 2} in electrocoagulation process.

  18. A review of passive thermal management of LED module

    Institute of Scientific and Technical Information of China (English)

    Ye Huaiyu; Sau Koh; Henk van Zeijl; A. W. J. Gielen; Zhang Guoqi

    2011-01-01

    Recently, the high-brighmess LEDs have begun to be designed for illumination application The increased electrical currents used to drive LEDs lead to thermal issues. Thermal management for LED module is a key design parameter as high operation temperature directly affects their maximum light output, quality, reliability and life time In this review, only passive thermal solutions used on LED module will be studied. Moreover, new thermal interface materials and passive thermal solutions applied on electronic equipments are discussed which have high potential to enhance thc thermal performance of LED Module.

  19. Feeling blue? Blue phosphors for OLEDs

    Directory of Open Access Journals (Sweden)

    Hungshin Fu

    2011-10-01

    Full Text Available Research on organic light emitting diodes (OLEDs has been revitalized, partly due to the debut of the OLED TV by SONY in 2008. While there is still plenty of room for improvement in efficiency, cost-effectiveness and longevity, it is timely to report on the advances of light emitting materials, the core of OLEDs, and their future perspectives. The focus of this account is primarily to chronicle the blue phosphors developed in our laboratory. Special attention is paid to the design strategy, synthetic novelty, and their OLED performance. The report also underscores the importance of the interplay between chemistry and photophysics en route to true-blue phosphors.

  20. Blue emitting KSCN:xCe phosphor for solid state lighting

    International Nuclear Information System (INIS)

    The intense blue emitting phosphor KSCN:xCe (x=0.005, 0.01, 0.02, 0.04) is synthesized by a simple, time saving, economical method of re-crystallization through aqueous solution at 353 K. Photoluminescence measurements showed that the said phosphor exhibits emission with good intensity peaking at 450 nm corresponding to d→f transitions of Ce3+ ion. The excitation spectra monitored at 450 nm shows small peak at 282 nm and broad intense excitation band peaking at 350 nm. The latter lies in near ultraviolet (350–410 nm) emission of UV LED. The phosphor KSCN:0.02Ce3+ shows CIE 1931 color coordinates as (0.1484, 0.0602) whereas the commercial blue phosphor BAM:Eu2+ shows the color co-ordinates as (0.1417, 0.1072), respectively, indicating better color purity for KSCN: 0.02Ce3+ compared to the BAM:Eu2+ phosphor. The color coordinates of KSCN: 0.02Ce3+ phosphor (0.1484, 0.0602) are nearer to the color coordinate for blue color suggested by the color systems EBUPAL/SECAM, sRGB Blue as well as Adobe blue(0.15, 0.06). -- Highlights: • Novel phosphor KSCN:xCe prepared for the first time. • Method is simple, time saving, economical, easy to handle. • Intense, blue, Characteristic Ce3+ emission at 450 nm. • nUV excitation, suitable for solid state lighting

  1. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants

    International Nuclear Information System (INIS)

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  2. Blue-green algae

    Science.gov (United States)

    ... Lac Klamath, Anabaena, Aphanizomenon flos-aquae, Arthrospira maxima, Arthrospira platensis, BGA, Blue Green Algae, Blue-Green Micro-Algae, Cyanobacteria, Cyanobactérie, Cyanophycée, Dihe, Espirulina, Hawaiian Spirulina, Klamath, Klamath Lake Algae, Lyngbya wollei, Microcystis aeruginosa, ...

  3. Blue-green algae

    Science.gov (United States)

    ... unresponsive to other treatments, taking 500 mg of spirulina blue-green algae by mouth 3 times daily for 6 months ... was seen in undernourished children who were given spirulina blue-green algae with a combination of millet, soy and peanut ...

  4. Templated blue phases.

    Science.gov (United States)

    Ravnik, Miha; Fukuda, Jun-ichi

    2015-11-21

    Cholesteric blue phases of a chiral liquid crystal are interesting examples of self-organised three-dimensional nanostructures formed by soft matter. Recently it was demonstrated that a polymer matrix introduced by photopolymerization inside a bulk blue phase not only stabilises the host blue phase significantly, but also serves as a template for blue phase ordering. We show with numerical modelling that the transfer of the orientational order of the blue phase to the surfaces of the polymer matrix, together with the resulting surface anchoring, can account for the templating behaviour of the polymer matrix inducing the blue phase ordering of an achiral nematic liquid crystal. Furthermore, tailoring the anchoring conditions of the polymer matrix surfaces can bring about orientational ordering different from those of bulk blue phases, including an intertwined complex of the polymer matrix and topological line defects of orientational order. Optical Kerr response of templated blue phases is explored, finding large Kerr constants in the range of K = 2-10 × 10(-9) m V(-2) and notable dependence on the surface anchoring strength. More generally, the presented numerical approach is aimed to clarify the role and actions of templating polymer matrices in complex chiral nematic fluids, and further to help design novel template-based materials from chiral liquid crystals. PMID:26412643

  5. Damage of photoreceptor-derived cells in culture induced by light emitting diode-derived blue light

    OpenAIRE

    Kuse, Yoshiki; Ogawa, Kenjiro; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Hara, Hideaki

    2014-01-01

    Our eyes are increasingly exposed to light from the emitting diode (LED) light of video display terminals (VDT) which contain much blue light. VDTs are equipped with televisions, personal computers, and smart phones. The present study aims to clarify the mechanism underlying blue LED light-induced photoreceptor cell damage. Murine cone photoreceptor-derived cells (661 W) were exposed to blue, white, or green LED light (0.38 mW/cm2). In the present study, blue LED light increased reactive oxyg...

  6. ZnSe-based white LEDs

    Science.gov (United States)

    Katayama, K.; Matsubara, H.; Nakanishi, F.; Nakamura, T.; Doi, H.; Saegusa, A.; Mitsui, T.; Matsuoka, T.; Irikura, M.; Takebe, T.; Nishine, S.; Shirakawa, T.

    2000-06-01

    The first phosphor-free white LED based on II-IV compound materials is demonstrated. Our device utilizes a phenomenon unique to ZnSe homoepitaxy, where a portion of the main greenish-blue emission from the active layer of a pn junction diode is absorbed by the conductive substrate which in turn gives off an intense broad-band yellow emission centered around 585 nm by photoluminescence. These two emission bands combine to give a spectrum which appears white to the naked eye. A typical ZnSe-based white LED lamp exhibits a color temperature of approximately 3400 K with a CRI (color rendering index) of 68. The optical output power and operating voltage of such a device at a forward current of 20 mA is 2.0 mW and 2.7 V, respectively. The luminous efficiency estimated from these results is 10.4l m/W, which is comparable to the incandescent lamp as well as the commercial InGaN-based white LED. Device lifetimes (half-life) have exceeded 800 h at 20°C.

  7. Blue ocean strategy.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2004-10-01

    Despite a long-term decline in the circus industry, Cirque du Soleil profitably increased revenue 22-fold over the last ten years by reinventing the circus. Rather than competing within the confines of the existing industry or trying to steal customers from rivals, Cirque developed uncontested market space that made the competition irrelevant. Cirque created what the authors call a blue ocean, a previously unknown market space. In blue oceans, demand is created rather than fought over. There is ample opportunity for growth that is both profitable and rapid. In red oceans--that is, in all the industries already existing--companies compete by grabbing for a greater share of limited demand. As the market space gets more crowded, prospects for profits and growth decline. Products turn into commodities, and increasing competition turns the water bloody. There are two ways to create blue oceans. One is to launch completely new industries, as eBay did with online auctions. But it's much more common for a blue ocean to be created from within a red ocean when a company expands the boundaries of an existing industry. In studying more than 150 blue ocean creations in over 30 industries, the authors observed that the traditional units of strategic analysis--company and industry--are of limited use in explaining how and why blue oceans are created. The most appropriate unit of analysis is the strategic move, the set of managerial actions and decisions involved in making a major market-creating business offering. Creating blue oceans builds brands. So powerful is blue ocean strategy, in fact, that a blue ocean strategic move can create brand equity that lasts for decades. PMID:15559577

  8. Heterostructures for Increased Quantum Efficiency in Nitride LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Robert F. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2010-09-30

    Task 1. Development of an advanced LED simulator useful for the design of efficient nitride-based devices. Simulator will contain graphical interface software that can be used to specify the device structure, the material parameters, the operating conditions and the desired output results. Task 2. Theoretical and experimental investigations regarding the influence on the microstructure, defect concentration, mechanical stress and strain and IQE of controlled changes in the chemistry and process route of deposition of the buffer layer underlying the active region of nitride-based blue- and greenemitting LEDs. Task 3. Theoretical and experimental investigations regarding the influence on the physical properties including polarization and IQE of controlled changes in the geometry, chemistry, defect density, and microstructure of components in the active region of nitride-based blue- and green-emitting LEDs. Task 4. Theoretical and experimental investigations regarding the influence on IQE of novel heterostructure designs to funnel carriers into the active region for enhanced recombination efficiency and elimination of diffusion beyond this region. Task 5. Theoretical and experimental investigations regarding the influence of enhanced p-type doping on the chemical, electrical, and microstructural characteristics of the acceptor-doped layers, the hole injection levels at Ohmic contacts, the specific contact resistivity and the IQE of nitride-based blue- and green-emitting LEDs. Development and optical and electrical characterization of reflective Ohmic contacts to n- and p-type GaN films.

  9. Photoluminescent carbon quantum dots as a directly film-forming phosphor towards white LEDs

    Science.gov (United States)

    Zhang, Feng; Feng, Xiaoting; Zhang, Yi; Yan, Lingpeng; Yang, Yongzhen; Liu, Xuguang

    2016-04-01

    Photoluminescent organosilane-functionalized carbon quantum dots (CQDs), 3.0-3.5 nm in diameter, were synthesized via a facile hydrothermal method using citric acid monohydrate as a precursor and N-(3-(trimethoxysilyl) propyl) ethylenediamine as a coordinating and passivation agent. The optical properties of the as-obtained CQDs were investigated in detail. The CQD aqueous solution emits bright blue-white light under ultraviolet (UV) illumination with a quantum yield of 57.3% and high red-green-blue (RGB) spectral composition of 60.1%, and in particular the CQDs exhibit excitation-independent photoluminescence. The CQDs have a narrow size distribution around 3.1 nm and good film-forming ability through simple heat-treatment. By virtue of these excellent optical characteristics and good film-forming ability, a white light-emitting device (LED) was fabricated by combining a UV-LED chip with a single CQD phosphor film, which exhibited cool white light with a CIE coordinate of (0.31, 0.36), a color rendering index of 84 and a correlated color temperature of 6282 K. In addition, the white LED exhibits good optical stability under various working currents and for different working time intervals. Moreover, the interaction between the carbogenic core and surface groups was discussed using the DMol3 program based on density functional theory. This research suggests the great potential of CQDs for solid-state lighting systems and reveals the effect of the surface state on the photoluminescent mechanism of CQDs.

  10. EDITORIAL: LED light sources (light for the future) LED light sources (light for the future)

    Science.gov (United States)

    Grandjean, N.

    2010-09-01

    Generating white light from electricity with maximum efficacy has been a long quest since the first incandescent lamp was invented by Edison at the end of the 19th century. Nowadays, semiconductors are making reality the holy grail of converting electrons into photons with 100% efficiency and with colours that can be mixed for white light illumination. The revolution in solid-state lighting (SSL) dates to 1994 when Nakamura reported the first high-brightness blue LED based on GaN semiconductors. Then, white light was produced by simply combining a blue dye with a yellow phosphor. After more than a decade of intensive research the performance of white LEDs is quite impressive, beating by far the luminous efficacy of compact fluorescent lamps. We are likely close to replacing our current lighting devices by SSL lamps. However, there are still technological and fabrication cost issues that could delay large market penetration of white LEDs. Interestingly, SSL may create novel ways of using light that could potentially limit electricity saving. Whatever the impact of SSL, it will be significant on our daily life. The purpose of this special cluster issue is to produce a snapshot of the current situation of SSL from different viewing angles. In an introductory paper, Tsao and co-workers from Sandia National Laboratories, present an energy-economics perspective of SSL considering societal changes and SSL technology evolution. In a second article, Narukawa et al working at Nichia Corporation—the pioneer and still the leading company in SSL—describe the state of the art of current research products. They demonstrate record performance with white LEDs exhibiting luminous efficacy of 183 lm W-1 at high-current injection. Then, a series of topical papers discuss in detail various aspects of the physics and technology of white LEDs Carrier localization in InGaN quantum wells has been considered the key to white LEDs' success despite the huge density of defects. A

  11. New York Blue

    Data.gov (United States)

    Federal Laboratory Consortium — New York Blue is used cooperatively by the Laboratory and Stony Brook University as part of the New York Center for Computation Sciences. Ranked as the 28th fastest...

  12. Code blue: seizures.

    Science.gov (United States)

    Hoerth, Matthew T; Drazkowski, Joseph F; Noe, Katherine H; Sirven, Joseph I

    2011-06-01

    Eyewitnesses frequently perceive seizures as life threatening. If an event occurs on the hospital premises, a "code blue" can be called which consumes considerable resources. The purpose of this study was to determine the frequency and characteristics of code blue calls for seizures and seizure mimickers. A retrospective review of a code blue log from 2001 through 2008 identified 50 seizure-like events, representing 5.3% of all codes. Twenty-eight (54%) occurred in inpatients; the other 22 (44%) events involved visitors or employees on the hospital premises. Eighty-six percent of the events were epileptic seizures. Seizure mimickers, particularly psychogenic nonepileptic seizures, were more common in the nonhospitalized group. Only five (17.9%) inpatients had a known diagnosis of epilepsy, compared with 17 (77.3%) of the nonhospitalized patients. This retrospective survey provides insights into how code blues are called on hospitalized versus nonhospitalized patients for seizure-like events. PMID:21546315

  13. LED light engine concept with ultra-high scalable luminance

    Science.gov (United States)

    Hoelen, Christoph; de Boer, Dick; Bruls, Dominique; van der Eyden, Joost; Koole, Rolf; Li, Yun; Mirsadeghi, Mo; Vanbroekhoven, Vincent; Van den Bergh, John-John; Van de Voorde, Patrick

    2016-03-01

    Although LEDs have been introduced successfully in many general lighting applications during the past decade, high brightness light source applications are still suffering from the limited luminance of LEDs. High power LEDs are generally limited in luminance to ca 100 Mnit (108 lm/m2sr) or less, while dedicated devices for projection may achieve luminance values up to ca 300 Mnit with phosphor converted green. In particular for high luminous flux applications with limited étendue, like in front projection systems, only very modest luminous flux values in the beam can be achieved with LEDs compared to systems based on discharge lamps. In this paper we introduce a light engine concept based on a light converter rod pumped with blue LEDs that breaks through the étendue and brightness limits of LEDs, enabling LED light source luminance values that are more than 4 times higher than what can be achieved with LEDs so far. In LED front projection systems, green LEDs are the main limiting factor. With our green light emitting modules, peak luminance values well above 1.2 Gnit have been achieved, enabling doubling of the screen brightness of LED based DLP projection systems, and even more when this technology is applied to other colors as well. This light source concept, introduced as the ColorSpark High Lumen Density (HLD) LED technology, enables a breakthrough in the performance of LED-based light engines not only for projection, where >2700 ANSI lm was demonstrated, but for a wide variety of high brightness applications.

  14. Measuring the bioactivity and molecular conformation of typically globular proteins with phenothiazine-derived methylene blue in solid and in solution: A comparative study using photochemistry and computational chemistry.

    Science.gov (United States)

    Ding, Fei; Xie, Yong; Peng, Wei; Peng, Yu-Kui

    2016-05-01

    Methylene blue is a phenothiazine agent, that possesses a diversity of biomedical and biological therapeutic purpose, and it has also become the lead compound for the exploitation of other pharmaceuticals such as chlorpromazine and the tricyclic antidepressants. However, the U.S. Food and Drug Administration has acquired cases of detrimental effects of methylene blue toxicities such as hemolytic anemia, methemoglobinemia and phototoxicity. In this work, the molecular recognition of methylene blue by two globular proteins, hemoglobin and lysozyme was characterized by employing fluorescence, circular dichroism (CD) along with molecular modeling at the molecular scale. The recognition of methylene blue with proteins appears fluorescence quenching via static type, this phenomenon does cohere with time-resolved fluorescence lifetime decay that nonfluorescent protein-drug conjugate formation has a strength of 10(4)M(-1), and the primary noncovalent bonds, that is hydrogen bonds, π-conjugated effects and hydrophobic interactions were operated and remained adduct stable. Meantime, the results of far-UV CD and synchronous fluorescence suggest that the α-helix of hemoglobin/lysozyme decreases from 78.2%/34.7% (free) to 58.7%/23.8% (complex), this elucidation agrees well with the elaborate description of three-dimensional fluorescence showing the polypeptide chain of proteins partially destabilized upon conjugation with methylene blue. Furthermore, both extrinsic fluorescent indicator and molecular modeling clearly exhibit methylene blue is situated within the cavity constituted by α1, β2 and α2 subunits of hemoglobin, while it was located at the deep fissure on the lysozyme surface and Trp-62 and Trp-63 residues are nearby. With the aid of computational analyses and combining the wet experiments, it can evidently be found that the recognition ability of proteins for methylene blue is patterned upon the following sequence: lysozyme

  15. Automated selection of LEDs by luminance and chromaticity coordinate

    CERN Document Server

    Fischer, Ulrich H P; Reinboth, Christian

    2010-01-01

    The increased use of LEDs for lighting purposes has led to the development of numerous applications requiring a pre-selection of LEDs by their luminance and / or their chromaticity coordinate. This paper demonstrates how a manual pre-selection process can be realized using a relatively simple configuration. Since a manual selection service can only be commercially viable as long as only small quantities of LEDs need to be sorted, an automated solution suggests itself. This paper introduces such a solution, which has been developed by Harzoptics in close cooperation with Rundfunk Gernrode. The paper also discusses current challenges in measurement technology as well as market trends.

  16. Two phosphor converted white LED with improved CRI

    International Nuclear Information System (INIS)

    Most of the commercial white LED lamps use blue chip coated with yellow emitting phosphor. Use of blue excitable red and green phosphors is expected to improve CRI. Several phosphors such as SrGa2S4:Eu2+, (Sr,Ba)SiO4:Eu2+ have been suggested in the past as green components. However, there are issues of sensitivity and stability of such phosphors. Here, we describe gallium substituted YAG:Ce3+ phosphor as a green emitter. YAG structures are already accepted by the industry for the stability and efficiency. LED’s with improved CRI could be fabricated by choosing Y3Al4GaO12:Ce3+ (green and yellow) and SrS:Eu2+ (red) phosphors along with blue chip. -- Highlights: ► New results on LED coated with blend of Y3Al4GaO12:Ce3+ and SrS:Eu2+ phosphors. ► All four emissions, viz. blue, green, yellow and red can be seen in mixture of phosphors. ► The colour can be tuned by changing the ratio of phosphor concentration in epoxy. ► Colour coordinates 0.32, 0.34 were typically obtained with CRI 85

  17. Two phosphor converted white LED with improved CRI

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, P.J., E-mail: yadav.pooja75@yahoo.in [Physics Department, Shri Ramdeobaba K. N. Engineering College, Katol Road, Nagpur-440 013, Maharashtra (India); Joshi, C.P. [Physics Department, Shri Ramdeobaba K. N. Engineering College, Katol Road, Nagpur-440 013, Maharashtra (India); Moharil, S.V., E-mail: svmoharil@yahoo.com [Department of Physics, R.T.M. Nagpur University, Nagpur-440010, Maharashtra (India)

    2013-04-15

    Most of the commercial white LED lamps use blue chip coated with yellow emitting phosphor. Use of blue excitable red and green phosphors is expected to improve CRI. Several phosphors such as SrGa{sub 2}S{sub 4}:Eu{sup 2+}, (Sr,Ba)SiO{sub 4}:Eu{sup 2+} have been suggested in the past as green components. However, there are issues of sensitivity and stability of such phosphors. Here, we describe gallium substituted YAG:Ce{sup 3+} phosphor as a green emitter. YAG structures are already accepted by the industry for the stability and efficiency. LED’s with improved CRI could be fabricated by choosing Y{sub 3}Al{sub 4}GaO{sub 12}:Ce{sup 3+} (green and yellow) and SrS:Eu{sup 2+} (red) phosphors along with blue chip. -- Highlights: ► New results on LED coated with blend of Y{sub 3}Al{sub 4}GaO{sub 12}:Ce{sup 3+} and SrS:Eu{sup 2+} phosphors. ► All four emissions, viz. blue, green, yellow and red can be seen in mixture of phosphors. ► The colour can be tuned by changing the ratio of phosphor concentration in epoxy. ► Colour coordinates 0.32, 0.34 were typically obtained with CRI 85.

  18. Powerful nanosecond light sources based on LEDs for astroparticle physics experiments

    CERN Document Server

    Lubsandorzhiev, B K; Shaibonov, B A J; Vyatchin, Y E

    2007-01-01

    Powerful nanosecond light sources based on LEDs have been developed for use in astroparticle physics experiments. The light sources use either matrixes of ultra bright blue LEDs or a new generation high power blue LEDs. It's shown that such light sources have light yield of up to 10**10 - 10**12 photons per pulse with very fast light emission kinetics. The described light sources are important for use in calibration systems of Cherenkov and scintillator detectors. The developed light sources are currently used successfully in a number of astroparticle experiments, namely: the TUNKA EAS experiment, the Baikal neutrino experiment etc.

  19. An LED-based Flasher System for VERITAS

    OpenAIRE

    D. Hanna(Physics Department, McGill University, Montreal, QC H3A 2T8, Canada); McCann, A; McCutcheon, M.; Nikkinen, L.

    2009-01-01

    We describe a flasher system designed for use in monitoring the gains of the photomultiplier tubes used in the VERITAS gamma-ray telescopes. This system uses blue light-emitting diodes (LEDs) so it can be operated at much higher rates than a traditional laser-based system. Calibration information can be obtained with better statistical precision with reduced loss of observing time. The LEDs are also much less expensive than a laser. The design features of the new system are presented, along w...

  20. An LED-based Flasher System for VERITAS

    CERN Document Server

    Hanna, D; McCutcheon, M; Nikkinen, L; 10.1016/j.nima.2009.10.107

    2009-01-01

    We describe a flasher system designed for use in monitoring the gains of the photomultiplier tubes used in the VERITAS gamma-ray telescopes. This system uses blue light-emitting diodes (LEDs) so it can be operated at much higher rates than a traditional laser-based system. Calibration information can be obtained with better statistical precision with reduced loss of observing time. The LEDs are also much less expensive than a laser. The design features of the new system are presented, along with measurements made with a prototype mounted on one of the VERITAS telescopes.

  1. Low-Cost Illumination-Grade LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Epler, John

    2013-08-31

    technology was commercialized in our LUXEON Q product in Sept., 2013. Also, the retention of the sapphire increased the robustness of the device, enabling sales of low-cost submount-free chips to lighting manufacturers. Thus, blue LED die sales were initiated in the form of a PSS-FC in February, 2013.

  2. Color mixing collimating lamp based on RGB LEDs

    Science.gov (United States)

    Lo, Yi-Chien; Moreno, Ivan; Chiu, Bo-Chun; Chien, Wei-Ting; Cai, Jhih-You; Chang, Yu-Yu; Sun, Ching-Cherng

    2012-10-01

    A novel light luminaire is proposed and experimentally analyzed, which efficiently mixes and projects the tunable light from red, green and blue (RGB) light-emitting diodes (LEDs). Simultaneous light collimation and color mixing is a challenging task because most collimators separate colors, and most color mixers spread the light beam. We performed an experimental study to find a balance between optical efficiency and color uniformity by changing light recycling and color mixing.

  3. The Blues of David Lynch

    OpenAIRE

    Roche, David

    2009-01-01

    This article is an attempt to elaborate a typology of the color blue in the color films of David Lynch up to and including Mulholland Drive (2001). The color blue is considered alternately as light, matter or verbal language. The author studies the use, function, value and meaning of blue lighting, divided into static and flashing light, and of the blue objects in Blue Velvet (1986) and Mulholland Drive. The author shows how Lynch appropriates connotations Western culture, under the influence...

  4. To LED or not to LED up a store

    OpenAIRE

    Quartier, Katelijn

    2013-01-01

    This presentation offers a wide talk about LED's and retail lighting. Questions like 'what might be its benefits regarding store experience', 'how do consumers experience LED-lit stores', 'is the use of coloured lighting in stores just a hype or is it a new condition' will be answered. Good and bad examples are used to illustrate the answers.

  5. Comparison of different LED Packages

    Science.gov (United States)

    Dieker, Henning; Miesner, Christian; Püttjer, Dirk; Bachl, Bernhard

    2007-09-01

    In this paper different technologies for LED packaging are compared, focusing on Chip on Board (COB) and SMD technology. The package technology which is used depends on the LED application. A critical fact in LED technology is the thermal management, especially for high brightness LED applications because the thermal management is important for reliability, lifetime and electrooptical performance of the LED module. To design certain and long life LED applications knowledge of the heat flow from LEDs to the complete application is required. High sophisticated FEM simulations are indispensable for modern development of high power LED applications. We compare simulations of various substrate materials and packaging technologies simulated using FLOTHERM software. Thereby different substrates such as standard FR4, ceramic and metal core printed circuit boards are considered. For the verification of the simulated results and the testing of manufactured modules, advanced measurement tools are required. We show different ways to experimentally characterize the thermal behavior of LED modules. The thermal path is determined by the transient thermal analysis using the MicReD T3Ster analyzer. Afterwards it will be compared to the conventional method using thermocouples. The heat distribution over the module is investigated by an IR-Camera. We demonstrate and compare simulation and measurement results of Chip-on-Board (COB) and Sub-Mounted Devices (SMD) technology. The results reveal that for different applications certain packages are ideal.

  6. Luminous efficacy and color rendering index of high power white LEDs packaged by using red phosphor

    International Nuclear Information System (INIS)

    We packaged a series of high power white LEDs by covering the blue LED chips with yellow phosphor, red phosphor and the two phosphors mixed by appropriate mass ratio, respectively, and discussed the excitation and emission spectrum of yellow phosphor and red phosphor and the characteristics of the LEDs. We found that the luminous efficacy of the white LEDs covered with the two phosphors mixed by appropriate mass ratio was lower than that of the white LEDs covered with yellow phosphor, but the color rendering index was improved observably. (semiconductor devices)

  7. Luminous efficacy and color rendering index of high power white LEDs packaged by using red phosphor*

    Institute of Scientific and Technical Information of China (English)

    Lu Pengzhi; Yang Hua; Wang Guohong

    2011-01-01

    We packaged a series of high power white LEDs by covering the blue LED chips with yellow phosphor,red phosphor and the two phosphors mixed by appropriate mass ratio, respectively, and discussed the excitation and emission spectrum of yellow phosphor and red phosphor and the characteristics of the LEDs. We found that the luminous efficacy of the white LEDs covered with the two phosphors mixed by appropriate mass ratio was lower than that of the white LEDs covered with yellow phosphor, but the color rendering index was improved observably.

  8. Color Temperature Tunable White-Light LED Cluster with Extrahigh Color Rendering Index

    OpenAIRE

    Minhao Zhang; Yu Chen; Guoxing He

    2014-01-01

    The correlated color temperature (CCT) tunable white-light LED cluster with extrahigh color rendering property has been found by simulation and fabricated, which consists of three WW LEDs (CCT = 3183 K), one red LED (634.1 nm), one green LED (513.9 nm), and one blue LED (456.2 nm). The experimental results show that this cluster can realize the CCT tunable white-lights with a color rendering index (CRI) above 93, special CRI R9 for strong red above 90, average value of the special CRIs of R9...

  9. Beyond Deep Blue

    CERN Document Server

    Newborn, Monty

    2011-01-01

    More than a decade has passed since IBM's Deep Blue computer stunned the world by defeating Garry Kasparov, the world chess champion at that time. Beyond Deep Blue tells the continuing story of the chess engine and its steady improvement. The book provides analysis of the games alongside a detailed examination of the remarkable technological progress made by the engines - asking which one is best, how good is it, and how much better can it get. Features: presents a total of 118 games, played by 17 different chess engines, collected together for the first time in a single reference; details the

  10. The Blue Collar Brain

    Directory of Open Access Journals (Sweden)

    Guy eVan Orden

    2012-06-01

    Full Text Available Much effort has gone into elucidating control of the body by the brain, less so the role of the body in controlling the brain. This essay develops the idea that the brain does a great deal of work in the service of behavior that is controlled by the body, a blue collar role compared to the white collar control exercised by the body. The argument that supports a blue collar role for the brain is also consistent with recent discoveries clarifying the white collar role of synergies across the body's tensegrity structure, and the evidence of critical phenomena in brain and behavior.

  11. Drift in LED based Photometer

    DEFF Research Database (Denmark)

    Paasch, Kasper

    1999-01-01

    During the development of a low cost industrial optical sensor an unexpected drift phenomenon has shown to be critical to performance. The sensor is based on LED's as light sources and the main source of error could be tracked to the instability of the spatial radiation pattern of the LED's. This...

  12. Integration of organic LEDs with inorganic LEDs for a hybrid lighting system

    International Nuclear Information System (INIS)

    We demonstrate that a surface-emitting hybrid light source can be realized by a combination of organic and inorganic light-emitting devices (LEDs). To this end, a blue inorganic LED bar is deployed at one side of a transparent light guide plate (LGP), and a yellow organic LED (OLED) is in contact with the rear surface of the LGP. In such a configuration, it is found that the overall luminance is almost equivalent to the sum of the luminances measured from each light source, and the overall luminance uniformity is determined mainly by the luminance uniformity of the OLED panel at high luminances. We have achieved a white color showing the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (x = 0.34, y = 0.33), the power efficiency of 9.3 lm/W, the luminance uniformity of 63% at the luminance of 3100 cd m–2, the color rendering index as high as 89.3, and the correlated color temperature finely tunable within the range between 3000 and 8000 K. Such a system facilitates color tuning by adjusting their luminous intensities and hence the implementation of the emotional lighting system. (paper)

  13. Blue light hazards for ocular lesions

    International Nuclear Information System (INIS)

    The blue light range (400-500 nm) of visible radiation stimulates specifically cones and rods of the retina. The carried energy by these wavelengths is absorbed and transferred to specific pigments. Their energy is sufficient to produce free radicals and singlet form of oxygen. Intense sources, rich in blue light radiation, may induce, in the retina, photo-toxic lesions either limited or short-lived or photothermal lesions more or less definitive. Repeated photo-toxic lesions should be the root for the age-related maculo-pathy (A.R.M.) also called late macular degeneration (A.M.D.). As a consequence, the attention should be drawn on the potential risk linked to modern lighting as 'daylight' lamp, compact fluorescent lamps, energy saving (C.F.L.) and light-emitting diodes (L.E.D.) for which a specific vigilance should be enforced. (author)

  14. The "Blue Banana" Revisited

    NARCIS (Netherlands)

    Faludi, A.K.F.

    2015-01-01

    This essay is about the “Blue Banana”. Banana is the name given subsequently by others to a Dorsale européenne (European backbone) identified empirically by Roger Brunet. In a background study to the Communication of the European Commission ‘Europe 2000’, Klaus Kunzmann and Michael Wegener put forwa

  15. Blue spectral inflation

    CERN Document Server

    Schunck, Franz E

    2008-01-01

    We reconsider the nonlinear second order Abel equation of Stewart and Lyth, which follows from a nonlinear second order slow-roll approximation. We find a new eigenvalue spectrum in the blue regime. Some of the discrete values of the spectral index n_s have consistent fits to the cumulative COBE data as well as to recent ground-base CMB experiments.

  16. Lichtauskopplung aus LEDs mittels Metallnanoteilchen

    OpenAIRE

    Göhler, Tino

    2011-01-01

    Der externe Wirkungsquerschnitt von auf AlGaAs/InGaAlP basierenden Leuchtdioden (LEDs) ist auf Grund von Totalreflexion infolge des hohen Brechungsindex des Halbleitermaterials (n=3...4) beschränkt. Auf die Oberfläche der LED aufgebrachte metallische Nanoteilchen (MNT) können jedoch als Dipolstreuer genutzt werden, um so die Emission der LED zu vergrößern. In dieser Arbeit wurden zunächst einzelne Goldnanoteilchen verschiedener Größe auf einer solchen Leuchtdiode in zwei verschiedenen Der ext...

  17. Phosphors and PDP, LED Technology

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Phosphors for PDP has good prospect for the largepotential of PDP industry. LED technology brings new marketto be developed. Developing phosphors for white LED withhigh efficiency and low light attenuation is an urgent work todo. Application of phosphors in color LED is in initial stage.1. Good Prospect of Phosphors for PDPColor PDP is widely used today. Three-prime-colorphosphor excited by VUV is the key material for color PDP.This makes research on three-prime-color phosphor for colorPDP important. Follow...

  18. Pientalojen energiatehokas led-valaistus

    OpenAIRE

    Viertokangas, Jarmo

    2016-01-01

    Tässä insinöörityössä on tehty tutkimus siitä, miten perinteisen valaistuksen muuttaminen led-valaistukseksi vaikuttaa pientaloenergian kulutukseen. Lisäksi on esimerkkikohteen valaistus- ja sähkösuunnitelma, jossa valaistus on toteutettu energiatehokkaalla led-valaistuksella. Tämä työ on tehty Veikkolan Sähköpalvelu Ky:lle selvitykseksi ja oppaaksi energiatehokkaasta valaistuksesta. Työssä käydään läpi yleisesti erilaisia led-valaistuksen eri vaihtoehtoja pientaloihin sekä mitä mahdollis...

  19. Yleisvalaistuksen muutos LED-valaistukseen

    OpenAIRE

    Heikkinen, Harri

    2015-01-01

    Päättötyön tavoite oli vertailla Mikalo Oy.n asuntokohteiden yleisvalaistuksen nykytilaa mahdolliseen LED-valaistuksella toteutettuun tilaan. Mikalo Oy.n 120.n kohteen yleisvalaistus on merkittävä sähkön kuluttaja, joten selvitys nykyisten valonlähteiden, kuten elohopealamppujen, vaihto voi säästää pitkäai-kaiskäytössä. Uusilla LED-valonlähteillä kulutus saadaan pienennettyä merkittävästi, mutta uusien, tehokkaiden LED-valaisimen hinnat ovat vielä suhteellisen korkealla, ja tämä oli huomi...

  20. Color uniformity and data simulation in high-power RGB LED modules using different LED-chips arrays

    Science.gov (United States)

    Tu, Yan; Jin, Shangzhong; Wang, Yanhua; Dou, Liangliang

    2007-11-01

    The continuing research efforts in white light created by mixing red, green and blue light emitting diodes (RGB LED) will allow their applications in high quality lighting systems in the (near) future. There are still many issues to tackle in this kind of light source, for instance the color uniformity and the change of color-render property owing to the change of LED's temperature. In this paper we simulate the effects on color uniformity of the near-field light distribution due to different LED-chips arrays (at optimum packaging density for uniform irradiance) using High-Power RGB LED-chips. The results showing the color uniformity of near-field which can be achieved with different RGB LED-chips arrays are presented. Several configurations of RGB LED-chips arrays and relevant data for color variation are given respectively. An analysis of luminous efficacy of radiation (LER) and color rendering index (CRI) of this source is performed, which are affected by the peak wavelength, spectral width, and the output peak emission power ratio of LED-chips.

  1. [Research on the influence of LED temperature shifts on differential optical absorption spectroscopy for measuring NO2].

    Science.gov (United States)

    Ling, Liu-Yi; Xie, Pin-Hua; Qin, Min; Zheng, Ni-Na; Ye, Cong-Lei; Li, Ang; Hu, Ren-Zhi

    2012-11-01

    Influences of LEDs (without etalon structure and center wavelengths are respectively 370 nm (near-UV), 452 nm (blue) and 660 nm(red)) temperature shifts on differential optical absorption spectroscopy(DOAS) for measuring NO2 were studied. NO2 absorption spectra were formed using LED emitting spectra at 10 degrees C. The measured LED spectra at other temperatures were used as reference spectra of DOAS. Thus, NO2 differential optical densities under different LED temperature shifts were acquired and then NO2 differential cross-sections were fitted to the acquired differential optical densities. From fitting results, the linear relations of 0.995, 0.945 and 0.989 correlation between delta of fitting residual and near-UV, blue and red LEDs temperature shifts were found and their slopes are respectively 1.12 x 10(-3), 5.25 x 10(-5) and 7.45 x 10(-4) degrees C(-1). The fitting results show that the influence of temperature shifts of blue LED on DOAS retrieval is negligible and the temperature shifts of near-UV and red LED are impressible to DOAS measurement resulting in degradation of detection sensitivity. The retrieval results of blue LED with and without etalon with similar temperature properties were compared and showed that etalon of LED will greatly increase the influence of temperature shifts of LED on DOAS retrieval. PMID:23387143

  2. Color temperature tunable white-light LED cluster with extrahigh color rendering index.

    Science.gov (United States)

    Zhang, Minhao; Chen, Yu; He, Guoxing

    2014-01-01

    The correlated color temperature (CCT) tunable white-light LED cluster with extrahigh color rendering property has been found by simulation and fabricated, which consists of three WW LEDs (CCT = 3183 K), one red LED (634.1 nm), one green LED (513.9 nm), and one blue LED (456.2 nm). The experimental results show that this cluster can realize the CCT tunable white-lights with a color rendering index (CRI) above 93, special CRI R9 for strong red above 90, average value of the special CRIs of R9 to R12 for the four saturated colors (red, yellow, green, and blue) above 83, and luminous efficacies above 70 lm/W at CCTs of 2719 K to 6497 K. PMID:24578665

  3. Color Temperature Tunable White-Light LED Cluster with Extrahigh Color Rendering Index

    Directory of Open Access Journals (Sweden)

    Minhao Zhang

    2014-01-01

    Full Text Available The correlated color temperature (CCT tunable white-light LED cluster with extrahigh color rendering property has been found by simulation and fabricated, which consists of three WW LEDs (CCT = 3183 K, one red LED (634.1 nm, one green LED (513.9 nm, and one blue LED (456.2 nm. The experimental results show that this cluster can realize the CCT tunable white-lights with a color rendering index (CRI above 93, special CRI R9 for strong red above 90, average value of the special CRIs of R9 to R12 for the four saturated colors (red, yellow, green, and blue above 83, and luminous efficacies above 70 lm/W at CCTs of 2719 K to 6497 K.

  4. Fabrication of High-power White LEDs and White Light Uniformity Testing

    Institute of Scientific and Technical Information of China (English)

    YU Xin-mei; RAO Hai-bo; HU Yue; LI Jun-fei; HOU Bin

    2007-01-01

    As the blue and yellow lights are complementary colors,a blue InGaN LED chip is coated by a yellow phosphor film to generate white light based on luminescence conversion mechanism.The emitted light of a blue LED is used as the primary source for exciting fluorescent material such as cerium doped yttrium aluminum garnet with the formula Y3Al5O12:Ce3+(in short:YAG:Ce3+).The matching of the spectrum of the blue LED chips and the YAG:Ce3+ yellow phosphor is studied to improve the conversion efficiency.The packaging methods and manufacturing processes for high-power single-chip-white-LEDs are introduced.The uniformity of the output white light is investigated.Based on the characteristics of the high-power white LEDs,some approaches and processes are suggested to improve the light uniformity when they are fabricated.The effectiveness of those approaches on the improvement of LEDs is discussed in detail and some interesting conclusions are also presented.

  5. Light pipes for LED measurements

    Science.gov (United States)

    Floyd, S. R.; Thomas, E. F., Jr.

    1976-01-01

    Light pipe directly couples LED optical output to single detector. Small area detector measures total optical output of diode. Technique eliminates thermal measurement problems and channels optical output to remote detector.

  6. Characteristics of high power LEDs at high and low temperature*

    Institute of Scientific and Technical Information of China (English)

    Guo Weling; Jia Xuejiao; Yin Fei; Cui Bifeng; Gao Wei; Liu Ying; Yan Weiwei

    2011-01-01

    The high power light emitting diodes (LEDs) based on InGaN and AlGaInP individually are tested on line at temperatures from -30 to 100 ℃. The data are fitted to measure the relationship between temperature and the properties of forward voltage, relative light intensity, wavelength, and spectral bandwidth of two different kinds of LEDs. Why these properties changed and how these changes reflected on applicatons are also analyzed and compared with each other. The results show that temperature has a great influence on the performance and application of power LEDs. For applications at low temperature, the forward voltage rising and the peak wavelength blue-shifting must be considered; and at high temperature, the relative light intensity decreasing and the peak wavelength red-shifting must be considered

  7. Novel chip coating approaches to improve white LED technology

    Science.gov (United States)

    Hartmann, Paul; Schweighart, Marko; Sommer, Christian; Wenzl, Franz-P.; Zinterl, Ernst; Hoschopf, Hans; Pachler, Peter; Tasch, Stefan

    2008-02-01

    Key market requirements for white LEDs, especially in the general lighting and automotive headlamp segments call for improved concepts and performance of white LEDs based on phosphor conversion. Major challenges are small emission areas, highest possible intensities, long-term color stability, and spatial homogeneity of color coordinates. On the other hand, the increasingly high radiation power of the blue LEDs poses problems for all involved materials. Various thick film coating technologies are widely used for applying the color conversion layer to the semiconductor chip. We present novel concepts based on Silicate phosphors with high performance in terms of spatial homogeneity of the emission and variability of the color temperature. Numerical calculation of the optical properties with the help of state-of-the-art simulation tools was used as a basis for the practical optimization of the layer geometries.

  8. Enhancement of astaxanthin production using Haematococcus pluvialis with novel LED wavelength shift strategy.

    Science.gov (United States)

    Xi, Tianqi; Kim, Dae Geun; Roh, Seong Woon; Choi, Jong-Soon; Choi, Yoon-E

    2016-07-01

    Haematococcus pluvialis is a green microalga of particular interest, since it is considered the best potential natural source of astaxanthin, which is widely used as an additive for natural pigmentation. In addition, astaxanthin has recently garnered commercial interest as a nutraceutical, cosmetic, and pharmaceutical. However, producing astaxanthin from H. pluvialis necessitates separation with distinctive culture conditions, dividing between the microalgae growth and the astaxanthin production stages. Light-emitting diodes (LEDs) have emerged as a replacement for traditional light sources, and LED applications are now rapidly expanding to multiple areas in fields such as biotechnology. However, further detail application into microalgae biotechnology remains limited. In this study, we have attempted to establish new protocols based on the specific wavelength of LEDs for the cultivation and production of astaxanthin using H. pluvialis. Specifically, we applied red LEDs for microalgae cell growth and then switched to blue LEDs to induce astaxanthin biosynthesis. The result showed that astaxanthin productions based on a wavelength shift from red to blue were significantly increased, compared to those with continuous illumination using red LEDs. Furthermore, additional increase of astaxanthin production was achieved with simultaneous application of exogenous carbon with blue LED illumination. Our approach based on the proper manipulation of LED wavelengths upon H. pluvialis cell stages will enable the improvement of biomass and enhance astaxanthin production using H. pluvialis. PMID:26860938

  9. Research on LED Fishing Light

    OpenAIRE

    Li Tian Hua; Jing Xing

    2013-01-01

    In this study , the semiconductor lighting technology with advantages of energy saving, environmental protection and high rapid response speed is regarded as the fishing light source, which can achieve targets of energy conservation, emission reduction, environmental protection, scientific fishing, etc. Then, the characteristics of LED are described to conduct a comparative analysis with the metal halide light source which has been commonly used in fishing light. The results show that LED is ...

  10. Farbmessung an LED-Systemen

    OpenAIRE

    Herrmann, Franziska

    2013-01-01

    Die Information über die farbliche Abstrahlcharakteristik von LED-Systemen wird immer wichtiger. Durch die zu Glühlampen und Leuchtstofflampen unterschiedliche Erzeugung von weißem Licht kann es bei LED-Systemen zu sichtbaren Farbunterschieden in der Abstrahlcharakteristik kommen. Im Rahmen dieser Arbeit wurde eine Methode zur Darstellung und Beschreibung dieser Farbunterschiede entwickelt, basierend auf gängigen Farbmessmethoden.

  11. Valuing Community-Led Design

    OpenAIRE

    Alexiou, Katerina; Zamenopoulos, Theodore; Alevizou, Giota

    2013-01-01

    The ideas and practice of community-led design, participatory design or co-design have a long-standing tradition, especially in the context of urban design, planning and architecture. Community-led design goes beyond the one-dimensional process of consultation, helping involve people in decision-making throughout the design process, from visioning to implementation. There are many benefits from this approach, from improving civic participation and ensuring more democratic outcomes, to creatin...

  12. Blue-green and green phosphors for lighting applications

    Science.gov (United States)

    Setlur, Anant Achyut; Chandran, Ramachandran Gopi; Henderson, Claire Susan; Nammalwar, Pransanth Kumar; Radkov, Emil

    2012-12-11

    Embodiments of the present techniques provide a related family of phosphors that may be used in lighting systems to generate blue or blue-green light. The phosphors include systems having a general formula of: ((Sr.sub.1-zM.sub.z).sub.1-(x+w)A.sub.wCe.sub.x).sub.3(Al.sub.1-ySi.s- ub.y)O.sub.4+y+3(x-w)F.sub.1-y-3(x-w) (I), wherein 0phosphors made accordingly to these formulations maintain emission intensity across a wide range of temperatures. The phosphors may be used in lighting systems, such as LEDs and fluorescent tubes, among others, to produce blue and blue/green light. Further, the phosphors may be used in blends with other phosphors, or in combined lighting systems, to produce white light suitable for illumination.

  13. Degradation Physics of High Power LEDs in Outdoor Environment and the Role of Phosphor in the degradation process.

    Science.gov (United States)

    Singh, Preetpal; Tan, Cher Ming

    2016-01-01

    A moisture- electrical - temperature (MET) test is proposed to evaluate the outdoor reliability of high power blue LEDs, with and without phosphor, and to understand the degradation physics of LEDs under the environment of combined humidity, temperature and electrical stresses. The blue LEDs with phosphor will be the high power white LEDs. Scanning acoustic microscopy is used to examine the resulted delamination during this test for the LEDs. The degradation mechanisms of blue LEDs (LEDs without phosphor) and white LEDs (LEDs with phosphor) are found to be different, under both the power on (i.e. with 350 mA through each LED) and power off (i.e. without current supply) conditions. Difference in the coefficient of thermal expansion between the molding part and the lens material as well as the heat generated by the phosphor layer are found to account for the major differences in the degradation mechanisms observed. The findings indicate that the proposed MET test is necessary for the LED industry in evaluating the reliability of LEDs under practical outdoor usage environment. PMID:27052103

  14. Degradation Physics of High Power LEDs in Outdoor Environment and the Role of Phosphor in the degradation process

    Science.gov (United States)

    Singh, Preetpal; Tan, Cher Ming

    2016-01-01

    A moisture- electrical – temperature (MET) test is proposed to evaluate the outdoor reliability of high power blue LEDs, with and without phosphor, and to understand the degradation physics of LEDs under the environment of combined humidity, temperature and electrical stresses. The blue LEDs with phosphor will be the high power white LEDs. Scanning acoustic microscopy is used to examine the resulted delamination during this test for the LEDs. The degradation mechanisms of blue LEDs (LEDs without phosphor) and white LEDs (LEDs with phosphor) are found to be different, under both the power on (i.e. with 350 mA through each LED) and power off (i.e. without current supply) conditions. Difference in the coefficient of thermal expansion between the molding part and the lens material as well as the heat generated by the phosphor layer are found to account for the major differences in the degradation mechanisms observed. The findings indicate that the proposed MET test is necessary for the LED industry in evaluating the reliability of LEDs under practical outdoor usage environment. PMID:27052103

  15. Remoção de azul de metileno de solução aquosa usando zeólitas sintetizadas com amostras de cinzas de carvão diferentes Removal of methylene blue from aqueous solution using zeolite synthesized from different coal fly ashes samples

    Directory of Open Access Journals (Sweden)

    Denise Alves Fungaro

    2009-01-01

    Full Text Available Batch sorption experiments were carried out to remove methylene blue from its aqueous solutions using zeolites synthesized from fly ashes as an adsorbent. The adsorbents were characterized by XFR, XRD and SEM. Nearly 90 min of contact time are found to be sufficient for the adsorption of dye to reach equilibrium. Equilibrium data have been analyzed using Langmuir and Freundlich isotherms and the results were found to be well represented by the Freundlich isotherm equation. Adsorption data were fitted to both Lagergren first-order and pseudo-second-order kinetic models and the data were found to follow pseudo-second-order kinetics.

  16. The Blue Emu

    Science.gov (United States)

    Descalzi, Doug; Gillett, John; Gordon, Carlton; Keener, ED; Novak, Ken; Puente, Laura

    1993-01-01

    The primary goal in designing the Blue Emu was to provide an airline with a cost efficient and profitable means of transporting passengers between the major cities in Aeroworld. The design attacks the market where a demand for inexpensive transportation exists and for this reason the Blue Emu is an attractive investment for any airline. In order to provide a profitable aircraft, special attention was paid to cost and economics. For example, in manufacturing, simplicity was stressed in structural design to reduce construction time and cost. Aerodynamic design employed a tapered wing which reduced the induced drag coefficient while also reducing the weight of the wing. Even the propulsion system was selected with cost effectiveness in mind, yet also to maintain the marketability of the aircraft. Thus, in every aspect of the design, consideration was given to economics and marketability of the final product.

  17. Synthesizing a Blue Ocean

    OpenAIRE

    Vester, Daniel

    2012-01-01

    The purpose of this Master thesis was to determine how electronic musical instrument companies could utilize innovation strategies to add value to their products and create new business markets beyond their core. The theoretical framework was established by outlining competitive strategies suitable for adoption by electronic musical instrument companies. The Blue Ocean Strategy was compared to traditional competitive strategies such as Porter’s Five Forces, and subsequently chosen because of ...

  18. Effects of blue pulsed light on human physiological functions and subjective evaluation

    Directory of Open Access Journals (Sweden)

    Katsuura Tetsuo

    2012-09-01

    Full Text Available Abstract Background It has been assumed that light with a higher irradiance of pulsed blue light has a much greater influence than that of light with a lower irradiance of steady blue light, although they have the same multiplication value of irradiance and duration. We examined the non-visual physiological effects of blue pulsed light, and determined whether it is sensed visually as being blue. Findings Seven young male volunteers participated in the study. We placed a circular screen (diameter 500 mm in front of the participants and irradiated it using blue and/or white light-emitting diodes (LEDs, and we used halogen lamps as a standard illuminant. We applied three steady light conditions of white LED (F0, blue LED + white LED (F10, and blue LED (F100, and a blue pulsed light condition of a 100-μs pulse width with a 10% duty ratio (P10. The irradiance of all four conditions at the participant's eye level was almost the same, at around 12 μW/cm2. We measured their pupil diameter, recorded electroencephalogram readings and Kwansei Gakuin Sleepiness Scale score, and collected subjective evaluations. The subjective bluish score under the F100 condition was significantly higher than those under other conditions. Even under the P10 condition with a 10% duty ratio of blue pulsed light and the F10 condition, the participant did not perceive the light as bluish. Pupillary light response under the P10 pulsed light condition was significantly greater than under the F10 condition, even though the two conditions had equal blue light components. Conclusions The pupil constricted under the blue pulsed light condition, indicating a non-visual effect of the lighting, even though the participants did not perceive the light as bluish.

  19. Blue light emitting diode internal and injection efficiency

    Directory of Open Access Journals (Sweden)

    Ilya E. Titkov

    2012-09-01

    Full Text Available A simple experimental method of light emitting diode (LED injection efficiency (IE determination was suggested. IE and internal quantum efficiency (IQE calculation is an actual and difficult problem in LED science. In this paper IE and IQE of blue LEDs were determined separately. The method is based on electroluminescence data fitting by the modified rate equation model. Efficiency droop caused by Auger recombination and poor injection were taken into account. Only one reasonable assumption was accepted during the calculations: IE tends to 1 at low current densities.

  20. Economic feasibility of solar-powered led roadway lighting

    Energy Technology Data Exchange (ETDEWEB)

    Wu, M.S.; Huang, H.H.; Huang, B.J.; Tang, C.W.; Cheng, C.W. [New Energy Center, Department of Mechanical Engineering, National Taiwan University, Taipei 10617 (China)

    2009-08-15

    The optical efficacy of light emitting diode (LED) has exceeded 72 lm/W in 2006. This implies that energy can be saved about 75%, as compared to mercury lamps widely used in roadway lighting. In some remote areas where the grid power cannot reach, independent solar-powered lighting using high-power LED provides a promising solution. However, the cost of solar photovoltaic device may cause the application of solar-powered LED roadway lighting to be not economically feasible. The present study investigates the design of the solar-powered LED roadway lighting using high-power LED luminaire (100 W) and estimates the installation cost for a 10 km highway with 2 lanes. LED luminaries are installed on both side of the road with staggered arrangement. The pole distance is 30 m. The cost comparison of LED lighting using grid and solar power with the conventional mercury lamps was carried out. It shows that the installation cost is 22 million USD for LED powered by grid power and 26 million USD for solar-powered. The total installation cost of conventional mercury lighting is 18 million USD. The excess cost of LED mainly comes from the cost of LED lamp and solar PV. But, the cost of power generation and electrical transmission line can be greatly reduced since about 75% energy was saved for LED. This permits the use of smaller copper wire and shorter line length for solar-powered system which in turn saves installation cost. The payback time for the excess investment of LED is 2.2 years for LED using grid power and 3.3 years for LED using solar power. (author)

  1. A new method to manipulate broiler chicken growth and metabolism: Response to mixed LED light system

    OpenAIRE

    Yefeng Yang; Yonghua Yu; Jinming Pan; Yibin Ying; Hong Zhou

    2016-01-01

    Present study introduced a new method to manipulate broiler chicken growth and metabolism by mixing the growth-advantage LED. We found that the green/blue LED mixed light system (G-B and G × B) have the similar stimulatory effect on chick body weight with single green light and single blue light (G and B), compared with normal artificial light (P = 0.028). Moreover, the percentage of carcass was significantly greater in the mixed light (G × B) when compared with the single light (P = 0.003). ...

  2. Impurity Influence on Nitride LEDs

    Directory of Open Access Journals (Sweden)

    O.I. Rabinovich

    2014-07-01

    Full Text Available Light emitting diodes (LEDs are widely used nowadays. They are used in major parts of our life. But it is still necessary to improve their characteristics. In this paper the impurity and Indium atoms influence on the LEDs characteristics is investigated by computer simulation. Simulation was carried out in Sim Windows. The program was improved for this purpose by creating new files for AlGaInN heterostructure and devices including more than 25 basic parameters. It was found that characteristics depend on impurity and indium atoms changes a lot. The optimum impurity concentration for doping barriers between quantum wells was achieved. By varying impurity and Indium concentration the distribution in AlGaInN heterostructure LEDs characteristics could be improved.

  3. LED-valaisimen markkinoille saattaminen

    OpenAIRE

    Ahola, Sami

    2015-01-01

    LED-valaisimien käyttö on yleistynyt sisä- ja ulkotilojen valaistuksessa ja niiden käyttö lisääntyy tulevien vuosien aikana nopeasti. LED-tekniikkaa hyödyntäviä valaisimia ja lamppuja on jo tällä hetkellä markkinoilla suuria määriä. Tämän opinnäytetyön tavoite oli laatia yhteenveto sähkölaitteen markkinoille saattamisesta huomioiden LED-valaisimien erityispiirteet. Työssä perehdyttiin sähkölaitteen markkinoille saattamisen prosessiin direktiivien, lainsäädännön ja standardien pohjalta. Ty...

  4. Radiochromic blue tetrazolium film dosimeter

    International Nuclear Information System (INIS)

    The colourless radiochromic chloride salt of blue tetrazolium (BT2+) is reduced radiolytically to the deep violet-coloured formazan. Dosimeter films of this radiation sensor can be produced by dissolving polyvinyl alcohol (PVA) in a heated aqueous solution of the salt, and, upon cooling, by casting the solution on a horizontal glass plate. In the present development, the resulting flexible transparent film is readily stripped from the plate, with a thickness of 0.045 mm. Upon irradiation with gamma rays or electron beams, a permanent image is produced with a broad absorption band in the visible spectrum. The radiation response is approximately a linear function in terms of the increase in optical absorbance (ΔA) measured at λmax 552 nm wavelength versus absorbed dose (D) over the range 5 to 50 kGy. The radiochromic image has a relatively high spatial resolution and can be used to register dose distributions and beam profiles. The value of ΔA shows a gradual increase for the first 24 hours after irradiation but is stable thereafter. The variation of response with irradiation temperature is negligible over the temperature range -20 deg. C to +30 deg. C, but displays a pronounced positive temperature dependence at higher temperatures. The response to gamma radiation shows negligible dose-rate dependence as long as the radiochromic sensor concentration in the PVA matrix is sufficiently high (> 6 % by weight). (author)

  5. Intradermal Alcian-Blue Injection Method to Trace Acupuncture Meridians

    OpenAIRE

    Baeckkyoung Sung; Min-Su Kim; Vyacheslav Ogay; Dae-In Kang; Kwang-Sup Soh

    2008-01-01

    Objective : In this article, we report on the intradermal Alcian blue staining method for tracing the meridians of acupuncture. Methods : 1% Alcian blue solution was injected into acupoints by using a 0.5mL insulin syringe with a 31-gauge needle, then the skin was incised and was observed under a stereoscopic microscope. The specimens were examined by using immunohistochemical methods and were observed under a confocal laser scanning microscope. Results : A threadlike structure, which w...

  6. Trypan blue identifies antimetabolite treatment area in trabeculectomy

    OpenAIRE

    Healey, P R; Crowston, J G

    2005-01-01

    Aim: Colourless solutions of mitomycin C (MMC) and 5-fluorouracil (5-FU) are widely used during trabeculectomy to inhibit postoperative scarring. The poor visibility of these agents on the eye has several drawbacks including the inability to accurately assess the area of treatment. This study examined the utility of using trypan blue dye to colour antimetabolites used during trabeculectomy and the effect of trypan blue on antimetabolite cytotoxicity in vitro.

  7. Linkages between NAMA - LEDS - MRV

    DEFF Research Database (Denmark)

    Agyemang-Bonsu, William; Benioff, Ron; Cox, Sadie;

    Low Emission Development Strategies (LEDS), Nationally Appropriate Mitigation Actions (NAMAs) and Monitoring, Reporting and Verification (MRV) are three of the key conceptual components emerging as part of the global architecture for a new climate agreement by 2015. The three components are...... how the three components are conceptually interlinked. Identifying the linkages can inform the work on each component and strengthen coordination of work in the context of the three big partnerships; the International Partnership on Mitigation and MRV, the LEDS Global Partnership and the NAMA...

  8. LED-belysning och brukaren

    OpenAIRE

    Adanko, Carina; Küller, Marianne

    2014-01-01

    Ljusforskning är om något diversifierad och omfattar teorier och metoder från skilda discipliner som teknik, medicin och samhällsvetenskap. Det finns också en förväntan att erhållna forskningsresultat skall kunna appliceras direkt i verkliga miljöer. I och med introduktionen av LED har många tidigare studier som behandlat glödlampor, lysrör och andra ljuskällor inaktualiserats. Ny kunskap - och ny forskning - krävs. En inventering av aktuell humanrelaterad LED-forskning genomfördes under 2013...

  9. Luminous Intensity of an LED as a Function of Input Power

    Directory of Open Access Journals (Sweden)

    Sean King

    2008-06-01

    Full Text Available When current passes through a light-emitting diode (LED, the LED emits an incoherent narrow spectrum of light. The relationship between the input power and the light intensity of an LED is studied in this research. Voltage ranging from 2 to 4 Volts was applied to a blue LED. The voltage across the LED, current through the LED and intensity of the light emitted by the LED were measured. For voltages ranging from 2.4 to 3.5 V, light intensity was found to be linearly related to both the current and the voltage. The input power was found to be directly proportional to the square of light intensity. For voltages above 3.5 V, the emission intensity remained constant, independent of the applied voltage.

  10. UV LED lighting for automated crystal centring

    International Nuclear Information System (INIS)

    A low-cost light-emitting diode (LED) UV source has been developed for facilitating macromolecular sample centring in the X-ray beam. A direct outcome of the exponential growth of macromolecular crystallography is the continuously increasing demand for synchrotron beam time, both from academic and industrial users. As more and more projects entail screening a profusion of sample crystals, fully automated procedures at every level of the experiments are being implemented at all synchrotron facilities. One of the major obstacles to achieving such automation lies in the sample recognition and centring in the X-ray beam. The capacity of UV light to specifically react with aromatic residues present in proteins or with DNA base pairs is at the basis of UV-assisted crystal centring. Although very efficient, a well known side effect of illuminating biological samples with strong UV sources is the damage induced on the irradiated samples. In the present study the effectiveness of a softer UV light for crystal centring by taking advantage of low-power light-emitting diode (LED) sources has been investigated. The use of UV LEDs represents a low-cost solution for crystal centring with high specificity

  11. LED color mixing with diffractive structures

    Science.gov (United States)

    Bonenberger, Theresa; Baumgart, Jörg; Wendel, Simon; Neumann, Cornelius

    2013-03-01

    Lighting solutions with colored LEDs provide many opportunities for illumination. One of these opportunities is to create a color tunable light source. In this way different kinds of white light (color temperature) as well as discrete colors may be realized. This opens the field for applications as mood lighting. But there is always a spatial separation of the distinct LEDs that might get converted into an angular separation by any collimating optics. This angular separation causes such problems like color fringes and colored shadows that cannot be accepted in most applications. Conventional methods to solve these problems include e.g. mixing rods or dichroic filters. A new approach is the use of the dispersive effect of a diffractive structure to compensate the angular separation of the different colors. In this contribution the potential and limitations of diffractive structures in LED color mixing applications are discussed. Ray tracing simulations were performed to analyze such important parameters like efficiency, color performance and the cross section of the color mixing optics. New means for the estimation of color mixing performance were developed. A software tool makes it possible to detect the color distribution within ray trace data and it provides a quality factor to estimate the color mixing performance. It can be shown that the spectral band width has a large influence on the mixing process. Ray tracing simulations are compared with results of an experimental setup such that both measured as well as simulated data is presented.

  12. White LED motorcycle headlamp design

    Science.gov (United States)

    Sun, Wen-Shing

    2015-09-01

    The motorcycle headlamp is composed of a white LED module, an elliptical reflector, a parabolic reflector and a toric lens. We use non-sequential ray to improve the optical efficiency of the compound reflectors. Using the toric lens can meet ECE_113 regulation and obtain a good uniformity.

  13. UV-LED photopolymerised monoliths

    Czech Academy of Sciences Publication Activity Database

    Abele, S.; Nie, F.; Foret, František; Paull, B.; Macka, M.

    2008-01-01

    Roč. 133, č. 7 (2008), s. 864-866. ISSN 0003-2654 R&D Projects: GA AV ČR KAN400310651 Institutional research plan: CEZ:AV0Z40310501 Keywords : photopolymerisation * UV- LED * polymethacrylate monolith Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.761, year: 2008

  14. Our Blue Gene Experience

    Czech Academy of Sciences Publication Activity Database

    Jakl, Ondřej; Starý, Jiří

    Ostrava : Ústav geoniky AV ČR, 2009 - (Blaheta, R.; Starý, J.), s. 50-54 ISBN 978-80-86407-60-9. [SNA '09 - Seminar on numerical analysis: modelling and simulation of challenging engineering problems. Ostrava (CZ), 02.02.2009-06.02.2009] R&D Projects: GA ČR(CZ) GA105/09/1830 Institutional research plan: CEZ:AV0Z30860518 Keywords : IBM Blue Gene/P * finite element solver * parallel scalability Subject RIV: BA - General Mathematics

  15. Estruturas fundamentais no blues

    OpenAIRE

    Silva, Rafael Palmeira da

    2012-01-01

    Resumo: Esta pesquisa tem como objeto de estudo a aplicação e adaptação da teoria de Schenker como ferramenta analítica aplicada ao jazz, tendo em vista a possibilidade de encontrar estruturas fundamentais distintas na música popular. Tendo como base as análises feitas por Larson (1998; 2009), Forte (2011) e Stock (1993) a pesquisa abordará, em um primeiro momento, as origens do jazz (blues e ragtime) como parte essencial para sua abordagem analítica, através da ótica etno-schenkeriana propos...

  16. LED lamp power management system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  17. LED lamp color control system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

    2013-02-05

    An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

  18. Low Cost Heart Rate Monitor Using Led-Led Sensor

    OpenAIRE

    Ahmed Mahrous Ragib

    2009-01-01

    A high sensitivity, low power and low cost sensor has been developed for photoplethysmography (PPG) measurement. The PPG principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. A standard light emitting diodes (LEDs) has been used as a light emitter and detector, and in order to reduce the space, cost and power, the classical analogue-to-digital converters (ADCs) replaced by the pulse-based signal conversion techniques. A general purpose ...

  19. LedTrix - Led-teknologian osaamispankki : Loppuraportti

    OpenAIRE

    Turunen, Lauri; Mönkkönen, Kari

    2014-01-01

    Tämä julkaisu on Ledtrix – Led-teknologian osaamispankki -hankkeen loppuraportti.Hanke toteutettiin vuosina 2010–2014. Hanketta rahoittivat Innovaatiorahoituskeskus Tekesin (Euroopan aluekehitysrahasto EAKR) lisäksi tutkimusosapuolet sekä yritykset. Hanke toteutettiin kolmena rinnakkaishankkeena, joissa tutkimusosapuolina olivat Karelia-ammattikorkeakoulun Liiketalouden ja tekniikan keskus, Itä-Suomen yliopiston fysiikan ja matematiikan laitos sekä Mikkelin ammattikorkeakoulu (30.3.2013 asti ...

  20. The effects of bluephase LED light on fibroblasts

    OpenAIRE

    Malčić, Ana Ivanišević; Pavičić, Ivan; Trošić, Ivančica; Simeon, Paris; Katanec, Davor; Krmek, Silvana Jukić

    2012-01-01

    Objective: The aim of this study was to evaluate the effect of Bluephase light emitting diode (LED) light on cell viability, colony-forming ability and proliferation in V79 cell culture and to determine how much the temperature of the nutrient medium rose. Methods: The investigation included a low (L), soft start (S) and high (H) illumination mode for 20, 40 and 80 seconds. The viability was determined by the trypan blue exclusion test, colony-forming ability by counting colonies 7 days after...

  1. A Color LED Driver Implemented by the Active Clamp Forward Converter

    OpenAIRE

    C. H. Chang; Cheng, H L; C. A. Cheng; E. C. Chang

    2013-01-01

    Because light emitting diodes (LEDs) have the advantages of dc working voltage, high luminescent efficiency, shortignition time, high reliability and pollution free, they have substituted for incandescent bulbs and fluorescent lampsgradually. In order to simplify circuit complexity, an active clamp forward converter with the sequential color display(SCD) control is proposed to drive red, green and blue (RGB) LED arrays. The proposed converter has zero-voltageswitching (ZVS) operations of both...

  2. Blue emitting undecaplatinum clusters

    Science.gov (United States)

    Chakraborty, Indranath; Bhuin, Radha Gobinda; Bhat, Shridevi; Pradeep, T.

    2014-07-01

    A blue luminescent 11-atom platinum cluster showing step-like optical features and the absence of plasmon absorption was synthesized. The cluster was purified using high performance liquid chromatography (HPLC). Electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry (MS) suggest a composition, Pt11(BBS)8, which was confirmed by a range of other experimental tools. The cluster is highly stable and compatible with many organic solvents.A blue luminescent 11-atom platinum cluster showing step-like optical features and the absence of plasmon absorption was synthesized. The cluster was purified using high performance liquid chromatography (HPLC). Electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry (MS) suggest a composition, Pt11(BBS)8, which was confirmed by a range of other experimental tools. The cluster is highly stable and compatible with many organic solvents. Electronic supplementary information (ESI) available: Details of experimental procedures, instrumentation, chromatogram of the crude cluster; SEM/EDAX, DLS, PXRD, TEM, FT-IR, and XPS of the isolated Pt11 cluster; UV/Vis, MALDI MS and SEM/EDAX of isolated 2 and 3; and 195Pt NMR of the K2PtCl6 standard. See DOI: 10.1039/c4nr02778g

  3. Blue tits are ultraviolet tits

    OpenAIRE

    Hunt, S; Bennett, A.T.D.; Cuthill, I. C.; Griffiths, R.

    1998-01-01

    The blue tit (Parus caeruleus) has been classified as sexually monochromatic. This classification is based on human colour perception yet, unlike humans, most birds have four spectrally distinct classes of cone and are visually sensitive to wavelengths in the near-ultraviolet (300 to 400 nm). Reflectance spectrophotometry reveals that blue tit plumage shows considerable reflection of UV light. For example, the blue crest shows peak reflectance at wavelengths around 352 nm. Furthermore, the bl...

  4. Postpartum Blues and Postpartum Depression

    OpenAIRE

    Erdem Ö et al.

    2009-01-01

    Postpartum blues which is seen during the postpartum period is a transient psychological state. Most of the mothers experience maternity blues in postpartum period. It remains usually unrecognized by the others. Some sensitive families can misattribute these feelings as depression. In this article, we tried to review the characteristics of maternity blues and its differences from depression. We defined depression and presented the incidence and diagnostic criteria, of major depression as well...

  5. LED应用%LED Operation

    Institute of Scientific and Technical Information of China (English)

    Michael Krickl

    2004-01-01

    LED(发光二极管)用于状态显示和矩阵面板已经很多年了。现在,可选用的LED包括新开发的蓝光和白光LED(广泛用于便携装置)以及普遍存在的绿光、红光和黄光LED。白光LED可做为彩显的理想背景照明。但是,在为LED设计电源时应注意这些新LED器件的固有特性。本文描述新、老LED的特性以及激励它们所需的电源性能。

  6. Colorimetric characterization of LED luminaires

    Science.gov (United States)

    Costa, C. L. M.; Vieira, R. R.; Pereira, R. C.; Silva, P. V. M.; Oliveira, I. A. A.; Sardinha, A. S.; Viana, D. D.; Barbosa, A. H.; Souza, L. P.; Alvarenga, A. D.

    2015-01-01

    The Optical Metrology Division of Inmetro - National Institute of Metrology, Quality and Technology has recently started the colorimetric characterization of lamps by implementing Correlated Color Temperature (CCT) and Color Rendering Index (CRI) measurements of incandescent lamps, followed by the CFL, and LED lamps and luminaires. Here we present the results for the verification of the color characterization of samples of SSL luminaires for public as well as indoor illumination that are sold in Brazil.

  7. Colorimetric characterization of LED luminaires

    International Nuclear Information System (INIS)

    The Optical Metrology Division of Inmetro – National Institute of Metrology, Quality and Technology has recently started the colorimetric characterization of lamps by implementing Correlated Color Temperature (CCT) and Color Rendering Index (CRI) measurements of incandescent lamps, followed by the CFL, and LED lamps and luminaires. Here we present the results for the verification of the color characterization of samples of SSL luminaires for public as well as indoor illumination that are sold in Brazil

  8. Luminescent ceramics for LED conversion

    Science.gov (United States)

    Raukas, M.; Wei, G.; Bergenek, K.; Kelso, J.; Zink, N.; Zheng, Y.; Hannah, M.; Stough, M.; Wirth, R.; Linkov, A.; Jermann, F.; Eisert, D.

    2011-03-01

    Many LED-based applications would benefit from more efficient and/or high lumen output devices that enable usage in both white and single color illumination schemes. In the present article we briefly review the materials research history leading to optical ceramic converters and discuss their typical characteristics. Recently demonstrated high performance values in terms of efficacy and external quantum efficiency in orange (amber) spectral region are described.

  9. 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.

    Science.gov (United States)

    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. PMID:27150785

  10. In vitro inactivation of Enterococcus faecalis with a led device.

    Science.gov (United States)

    D'Ercole, S; Spoto, G; Trentini, P; Tripodi, D; Petrini, M

    2016-07-01

    Non-coherent light-emitting diodes (LEDs) are effective in a large variety of clinical indications; however, the bactericidal activity of LEDs is unclear, although the effectiveness of such lights is well known. Currently, no studies have examined the effects of NIR-LED on bacteria. The aims of this study were to verify the antibacterial activity of 880-nm LED irradiation on a bacterial suspension of Enterococcus faecalis and to compare it with the actions of sodium hypochlorite (NaOCl) and the concurrent use of both treatments. Before we proceeded with the main experiment, we first performed preliminary tests to evaluate the influence of such parameters as the distance of irradiation, the energy density, the irradiation time and the presence of photosensitizers on the antimicrobial effects of LEDs. After treatment, the colony forming units per milliliter (CFU/mL) was recorded and the data were submitted to ANOVA and Bonferroni post hoc tests at a level of significance of 5%. The results showed that LED irradiation, at the parameters used, is able to significantly decrease E. faecalis viability in vitro. The total inhibition of E. faecalis was obtained throughout concurrent treatment of LED and NaOCl (1%) for 5min. The same antimicrobial activity was confirmed in all of the experiments (p<0.05), but no statistically significant differences were found by varying such parameters as the distance of irradiation (from 0.5mm to 10mm), energy density (from 2.37 to 8.15mJ/s), irradiation time (from 5min to 20min) or by adding toluidine blue O (TBO). PMID:27107704

  11. University of Nevada Las Vegas LED Display Engineering

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-08-31

    The primary objective of this part of the project is to develop and implement a method that compensates for the inefficiency of the green LED. The proposed engineering solution which will be the backbone of this project will be to use RGBW combination in every pixel to save energy. Two different RGBW geometrical pixel configurations will be implemented and compared against traditional LED configurations. These configurations will be analyzed for energy efficiency while keeping the quality of the display the same. Cost of the addition of white LEDs to displays along with energy cost savings will be presented and analyzed.

  12. Carrier Lifetimes in Fluorescent 6H-SiC for LEDs Application

    DEFF Research Database (Denmark)

    Grivickas, Vytautas; Gulbinas, Karolis; Jokubavičius, Valdas;

    acceptor pair recombination [1,2]. This combination can achieve higher electric-light conversion efficiency and high color rendering in comparison with today’s used blue GaN LED based and phosphors. The devices are promising candidates for general lightning applications and may obtain stability...

  13. Mesa-height Dependent Quantum Efficiency Characteristics of InGaN Micro-LEDs

    KAUST Repository

    Shen, Chao

    2013-01-01

    The mechanisms of mesa-height dependent efficiency and efficiency droop of blue InGaN/GaN micro-LED is presented. Device with a large etch-depth (> 1.3 µm) shows significant strain relief with aggravated current crowding.

  14. Instant BlueStacks

    CERN Document Server

    Judge, Gary

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English

  15. Case Study on Combination of Fluorescent Materials for White LED to Obtain High Color Rendering Indexes

    Science.gov (United States)

    Nayama, Shunsuke; Itoh, Kunio

    This letter reports on white-LED with high color rendering property. We realized the white-LED whose average Color Rendering Index (CRI) is as high as 94.2 by applying the commercial Red, Yellow, Green and Blue phosphors to near ultraviolet-LED. So far as we know, this value is the highest ever attained in white-LED around the color temperature of 5500[K]. In order to realize the good Ra (average CRI), we made a CRI simulator and simulated the spectrum distribution of white-LED with good Ra. The spectrum distribution obtained by this simulation was proved to be very useful as a landmark for realizing a prototype white-LED with good Ra.

  16. Laser ohjattava led-matriisi

    OpenAIRE

    Harri, Jarkko

    2011-01-01

    Työn alkuperäisenä tavoitteena oli kehittää näyttävä led matriisitaulu, jolla voi myös näyttää kuvia tietokoneen avulla. Matriisitaulua suunnitellessa tuli esiin toive isosta taulusta, jota voisi käyttää mainoksena, voisi piirtää laserosoittimen avulla kuvioita ja sen tulisi soveltua ulkokäyttöön. Matriisitaulu toteutettiin modulaarisena, joka mahdollistaa erikokoisien taulujen rakentamisen helposti. Valon kirkkauden tunnistamiseen käytetään matriisin ledejä. Yhden moduulin suurin tehonkulutu...

  17. LED-ajoneuvovalojen testauslaitteiston suunnittelu

    OpenAIRE

    Moilanen, Vitali

    2013-01-01

    Tässä työssä laajennettiin valmiina olevaa LED-ajovalojen testauslaitteistoa suunnittelemalla uusi käyttöliittymä ja lisäämällä uusia hyödyllisiä ominaisuuksia. Laitteeseen on lisätty tulosten esittelyä ja tarkastelua varten pieni 2-rivinen nestekidenäyttö ja USB:n avulla toteutettu yhteys tietokoneen kanssa. Lisäksi oli suunniteltu tietokoneohjelma Microsoft Visual Basicilla. Ohjelma on tarkoitettu laitteen hallintaan. Testauslaitteen ytimenä toimii Atmelin atMega48PA-mikro-ohjain ja s...

  18. Luokkahuoneen valaistus LED-tekniikalla

    OpenAIRE

    Malassu, Henri

    2013-01-01

    Tämä insinöörityö käsittää Kiinteistö Oy Mäkelän koulun luokkahuoneiden valaistus-selvityksen, jossa tutkittiin, löytyykö markkinoilta energiatehokkaita LED-valaisimia tai valonlähteitä vaihtoehdoiksi luokkahuoneen nykyisille T8-loisteputkivalaisimille. Uuden vaihtoehtoisen valaisimen tai valonlähteen tulisi olla energiatehokkaampi, mutta valaistuksen laadun tulisi kuitenkin pysyä vähintäänkin samana. Työ tehtiin Insinööritoimisto Leo Maaskola Oy:n tilauksesta. Aluksi selvitettiin markkin...

  19. LED-valaistuksen suunnittelu LEKOhalliin

    OpenAIRE

    Alanko, Lauri

    2014-01-01

    Opinnäytetyön tavoitteena oli selvittää, kannattaako nykyinen valaistus LEKOhalleissa vaihtaa LED-valaistukseen, ottaen huomioon sekä taloudellinen että valaistustekninen puoli. Tämän opinnäytetyön tarkoitus on toimia apuna, kun suunnitellaan valaistuksen uudistamista LEKOhalleihin. Opinnäytetyön tekemiselle oli monia syitä, joista yksi oli LEDien nopea kehitys viime vuosina. Lisäksi käyttäjien tyytymättömyys nykyiseen valaistukseen ja mahdollisten säästöjen saaminen olivat painavia syitä opi...

  20. [Adsorption of methylene blue from water by the biochars generated from crop residues].

    Science.gov (United States)

    Xu, Ren-Kou; Zhao, An-Zhen; Xiao, Shuang-Cheng; Yuan, Jin-Hua

    2012-01-01

    Biochars were prepared from straws of rice, peanut and soybean and rice hull using a low temperature pyrolysis method and adsorption of methylene blue by these biochars were investigated with batch and leaching experiments. Results indicated that biochars have high adsorption capacity for methylene blue and followed the order: rice straw char > soybean straw char > peanut straw char > rice hull char. This order is generally consistent with the amount of negative charge and specific surface area of these biochars. While methylene blue was mainly adsorbed specifically by the biochars, because the adsorption of methylene blue increased with the increase of ionic strength and the adsorption led to the shift of zeta potential of biochar particles to positive value direction. Langmuir equation fitted the adsorption isotherms well and can be used to describe the adsorption behaviors of methylene blue by the biochars. The maximum adsorption capacity of methylene blue predicted by langmuir equation was 196.1, 169.5, 129.9 and 89.3 mmol x kg(-1) for rice straw char, soybean straw char, peanut straw char and rice hull char, respectively. Leaching experiments show that rice hull char of 156 g can remove methylene blue from 30 L water containing 0.3 mmol x L(-1) of methylene blue completely and the cumulative amount of methylene blue absorbed by the biochar reaches 57.7 mmol x kg(-1). The biochars can be used as efficient adsorbents to remove methylene blue from waste water of dye. PMID:22452202

  1. Low Cost Heart Rate Monitor Using Led-Led Sensor

    Directory of Open Access Journals (Sweden)

    Ahmed Mahrous Ragib

    2009-01-01

    Full Text Available A high sensitivity, low power and low cost sensor has been developed for photoplethysmography (PPG measurement. The PPG principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. A standard light emitting diodes (LEDs has been used as a light emitter and detector, and in order to reduce the space, cost and power, the classical analogue-to-digital converters (ADCs replaced by the pulse-based signal conversion techniques. A general purpose microcontroller has been used for the implementation of measurement protocol. The proposed approach leads to better spectral sensitivity, increased resolution, reduction in cost, dimensions and power consumption. The basic sensing configuration presented is capable of detecting the PPG signal from a finger or toe, and it is very simple to extract the heart rate and heart rate variability from such a signal.

  2. FROM CIRCULAR ECONOMY TO BLUE ECONOMY

    Directory of Open Access Journals (Sweden)

    Iustin-Emanuel, ALEXANDRU

    2014-11-01

    Full Text Available Addressing the subject of this essay is based on the background ideas generated by a new branch of science - Biomimicry. According to European Commissioner for the Environment, "Nature is the perfect model of circular economy". Therefore, by imitating nature, we are witnessing a process of cycle redesign: production-consumption-recycling. The authors present some reflections on the European Commission's decision to adopt after July 1, 2014 new measures concerning the development of more circular economies. Starting from the principles of Ecolonomy, which is based on the whole living paradigm, this paper argues for the development within each economy of entrepreneurial policies related to the Blue economy. In its turn, Blue economy is based on scientific analyses that identify the best solutions in a business. Thus, formation of social capital will lead to healthier and cheaper products, which will stimulate entrepreneurship. Blue economy is another way of thinking economic practice and is a new model of business design. It is a healthy, sustainable business, designed for people. In fact, it is the core of the whole living paradigm through which, towards 2020, circular economy will grow more and more.

  3. Automated detection of Antarctic blue whale calls.

    Science.gov (United States)

    Socheleau, Francois-Xavier; Leroy, Emmanuelle; Pecci, Andres Carvallo; Samaran, Flore; Bonnel, Julien; Royer, Jean-Yves

    2015-11-01

    This paper addresses the problem of automated detection of Z-calls emitted by Antarctic blue whales (B. m. intermedia). The proposed solution is based on a subspace detector of sigmoidal-frequency signals with unknown time-varying amplitude. This detection strategy takes into account frequency variations of blue whale calls as well as the presence of other transient sounds that can interfere with Z-calls (such as airguns or other whale calls). The proposed method has been tested on more than 105 h of acoustic data containing about 2200 Z-calls (as found by an experienced human operator). This method is shown to have a correct-detection rate of up to more than 15% better than the extensible bioacoustic tool package, a spectrogram-based correlation detector commonly used to study blue whales. Because the proposed method relies on subspace detection, it does not suffer from some drawbacks of correlation-based detectors. In particular, it does not require the choice of an a priori fixed and subjective template. The analytic expression of the detection performance is also derived, which provides crucial information for higher level analyses such as animal density estimation from acoustic data. Finally, the detection threshold automatically adapts to the soundscape in order not to violate a user-specified false alarm rate. PMID:26627784

  4. Size effect on efficiency droop of blue light emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Y.B.; Chen, Z.Z. [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Institute of Photonics, University of Strathclyde, Glasgow G4 0NW (United Kingdom); Wang, S.Y.; Zhang, G.Y. [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Gong, Z.; Xie, E.Y.; Chen, Y.J.; Zhang, Y.F.; McKendry, J.; Massoubre, D.; Gu, E.D. [Institute of Photonics, University of Strathclyde, Glasgow G4 0NW (United Kingdom); Rae, B.R.; Henderson, R.K. [Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)

    2012-03-15

    In this paper, the size effects on the efficiency droop (ED) in blue InGaN/GaN quantum well light emitting diode are investigated. The smaller size LEDs can work well under much higher power density, especially when the size is reduced to under 40 micro-meters. It shows a weaker ED in these small LEDs. Time correlated single photon counting (TCSPC) measurements show a longer electroluminescence lifetime for smaller size LEDs, which implicates the nonradiative recombination is reduced. It is likely due to Auger recombination reduction by quantum well (QW) band flattened with the device size decreasing. Cathodoluminescence results indicates that the strain in QWs is relaxed both in the whole pillar and along radial direction of the pillar. The better performance of the smaller size LED is likely attributed to strain relaxation (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. County of Hawaii - A Unique LED Street Light Conversion

    Science.gov (United States)

    Thiel, Ronald LeRoy

    2015-08-01

    In 2010 the County of Hawaii was paying $0.40/kW-Hr for electricity, $1.5 mil annual bill for 8,500 street lights. Over the past 20 years costs have increased on an average of 7% per year. Inventory maintenance frequency for the 8,500 lights was 35%, which meant 3,000 visits per year. The current LPS street lights were nearing 20 years of service and a complete replacement was imminent, a significant cost for the County of Hawaii and its 185,000 citizens.The astronomy community impact was identified early on and discussions conducted for an acceptable conversion path. Key concerns centered on the blue light content of the LED and reflected light.A demo project with Federal ARRA funds installed 1,000 LED full cut off fixtures achieving an energy savings of $200K annually. The results were extremely successful and were loudly applauded by both the general public and the Astronomy Institute. Hence, the Traffic Division recommended to the County administration changing the remaining lights, now numbering 9,000, to new LED lights. The County administration approved the change to the LED lights and an upgrade to the outdoor lighting ordinance.The remainder of the conversion, amounting to $6 million for materials and labor, is expected to yield an energy savings of approximately $800K annually with a 5 year recovery of costs that includes both energy savings and maintenance reduction.Additional benefits achieved from using full cutoff fixtures include reduction in glare for drivers, pedestrians, and elimination of trespass light onto neighboring residences.Benefits achieved by using a filtered LED includes reducing blue light to <1 %, diffusing the harshness of the direct LED light and the ability to use the most energy efficient lumen producing fixture to achieve in excess of 63% reduction in energy costs.Additional aspects of this conversion presentation will include steps to gather quantitative data showing reduction in light pollution, aerial and satellite surveys for

  6. Broad-spectrum light versus blue light for phototherapy in neonatal hyperbilirubinemia: a randomized controlled trial.

    Science.gov (United States)

    Pratesi, Simone; Di Fabio, Sandra; Bresci, Cecilia; Di Natale, Cecilia; Bar, Shahar; Dani, Carlo

    2015-07-01

    Phototherapy is standard care for treatment of neonatal hyperbilirubinemia. Our aim was to compare the effectiveness of broad-spectrum light (BSL) to that of blue light emitting diodes (LED) phototherapy for the treatment of jaundiced late preterm and term infants. Infants with gestational age from 35(+0) to 41(+6) weeks of gestation and nonhemolytic hyperbilirubinemia were randomized to treatment with BSL phototherapy or blue LED phototherapy. A total of 20 infants were included in the blue LED phototherapy group and 20 in the BSL phototherapy group. The duration of phototherapy was lower in the BSL than in the blue LED phototherapy group (15.8 ± 4.9 vs. 20.6 ± 6.0 hours; p = 0.009), and infants in the former group had a lower probability (p = 0.015) of remaining in phototherapy than infants in the latter. We concluded that BSL phototherapy is more effective than blue LED phototherapy for the treatment of hyperbilirubinemia in late preterm and term infants. Our data suggest that these results are not due to the different irradiance of the two phototherapy systems, but probably depend on their different peak light emissions. PMID:25545446

  7. Developing Successful International Faculty Led Program

    Science.gov (United States)

    Fabregas Janeiro, Maria G.; Fabre, Ricardo Lopez; Rosete, Rodrigo Tello

    2012-01-01

    Faculty Led Programs are study abroad experiences led by university professors. Faculty Led Programs are considered as an opportunity for college students, especially in the United States to attend a short-term international experience (Mills, 2010). Faculty Led Program is an international experience which is different from the traditional…

  8. Healing process study in murine skin superficial wounds treated with the blue LED photocoagulator EMOLED

    Science.gov (United States)

    Rossi, Francesca; Cicchi, Riccardo; Tatini, Francesca; Bacci, Stefano; Alfieri, Domenico; De Siena, Gaetano; Pavone, Francesco S.; Pini, Roberto

    2015-07-01

    A faster healing process was observed in superficial skin wounds after irradiation with the EMOLED photocoagulator. The instrument consists of a compact handheld photocoagulation device, useful for inducing coagulation in superficial abrasions. In this work we present the results of an in vivo study, in a murine model. Two superficial wounds were produced on the back of 12 mice: one area was left untreated, the other one was treated with EMOLED. Healthy skin was used as a control. The animals were sacrificed 3 hours, 12 hours, 1 day, 6 day after treatment. The treatment effects on back skin was monitored by visual observations, histopathological analysis, immuno-histochemical analysis, and nonlinear microscopic imaging performed at each follow up time, finding no adverse reactions and no thermal damage in both treated areas and surrounding tissues. In addition, a faster healing process, a reduced inflammatory response, a higher collagen content, and a better-recovered skin morphology was evidenced in the treated tissue with respect to the untreated tissue. These morphological features were characterized by means of immuno-histochemical analysis, aimed at imaging fibroblasts and myofibroblasts, and by SHG microscopy, aimed at characterizing collagen organization, demonstrating a fully recovered aspect of dermis as well as a faster neocollagenesis in the treated regions. This study demonstrates that the selective photothermal effect we used for inducing immediate coagulation in superficial wounds is associated to a minimal inflammatory response, which provides reduced recovery times and improved healing process.

  9. Effects of blue light irradiation on dental enamel remineralization in vitro

    International Nuclear Information System (INIS)

    This study aimed to investigate the effects of blue radiation on dental enamel remineralization. In addition, a methodology of analysis was developed to evaluate alterations of enamel mineral content by optical coherence tomography. Artificial lesions were formed in bovine dental enamel slabs by immersing the samples in under saturated acetate buffer (2 mL/mm2 e 6.25 mL/mm2). The lesions were irradiated with blue LED (l=455±20nm), with radiant power of 110 mW, irradiance of 1.4 W/cm2, radiant exposure of 13.8 J/cm2 and exposure time of 10 s. Remineralization was induced by pH-cycling model during 8 days. Cross-sectional hardness and optical coherence tomography (OCT) were used to assess mineral changes after remineralization. Hardness data showed that non-irradiated enamel lesions presented higher mineral content than irradiated ones and this difference was more evident in lesions formed in higher solution volume. The analysis of OCT signal also demonstrated that the mineral content of non-irradiated group was higher than in irradiated one; however, no significant difference was observed. Furthermore, significant differences in OCT sign were detected between sound and demineralized enamel. Based on the results obtained in the present study it can be concluded that blue radiation caused an inhibition of enamel remineralization. The methodology adopted for OCT analysis allowed the quantification of enamel mineral loss; however, the remineralization process could not be evaluated by this technique. (author)

  10. Practical lighting design with LEDs

    CERN Document Server

    Lenk, Ron

    2011-01-01

    "This book covers all of the information needed to design LEDs into end-products. It is a practical guide, primarily explaning how things are done by practicing engineers. Equations are used only for practical calculations, and are kept to the level of high-school algebra. There are numerous drawings and schematics showing how things such as measurements are actually made, and showing curcuits that actually work. There are practical notes and examples embedded in the text that give pointers and how-to guides on many of the book's topics. After reading each chapter of the book, readers will have the knowledge to implement practical designs. This book will be kept as a reference tool for years to come"--

  11. Blue-sky thinking

    International Nuclear Information System (INIS)

    Global environmental problems - such as the greenhouse effect, the depletion of natural resources and the accumulation of wastes - have been recognized as common international issues affecting humanity since the 1990s. Sustainable development on a global scale is now sought, for instance, with the establishment of the targets for greenhouse gas reduction in the 1997 Kyoto Protocol, and with the adoption of the Declaration on Sustainable Development at the 2002 Johannesburg Summit. Honda launched the slogan 'Blue Sky for Children' in the 1960s when environmental pollution became a highly visible issue. During that decade we started an aggressive approach aimed at substantial environmental improvement, and unveiled the Compound Vortex Controlled Combustion (CVCC) engine - which used unique low-emission technology - in the United States and Japan. Since then, we have developed the Variable Valve Timing and Lift Electric Control System (VTEC) and the i-VTEC series with innovative engine technology, permitting global production of vehicles that combine high performance with state-of-the-art low-emission technologies. And we continued to work to preserve the global environment by releasing a hybrid vehicle, the Insight, which achieved the most efficient fuel consumption in the world at the time of its introduction in 1998

  12. Pengaturan Lampu Taman LED RGB Berbasis Arduino Yang Dilengkapi Solar Cell

    Directory of Open Access Journals (Sweden)

    Fina Supegina

    2014-02-01

    Full Text Available Pada saat ini perkembangan teknologi sudah semakin canggih. Dari waktu ke waktu perkembangan teknologi terus saja berkembang, dari teknologi yang semula menggunakan obor, petromaks, lampu pijar, lampu gas, hingga sampai ke lampu LED (Light Emiting Dioda. Semua lampu – lampu tersebut dibuat untuk membantu manusia untuk melakukan aktifitas di malam hari. Penggunaan lampu led pada masa kini banyak kita jumpai karena selain dapat digunakan untuk pencahayaan di malam hari dan juga lampu led dapat menghemat energi listrik dibandingkan dengan lampu pijar dan lampu gas.Penggunaan lampu LED RGB( Light Emiting Dioda Red, Green, Blue ini dapat dikontrol menggunakan remote untuk pengubahan warnanya dan sebagai receivernya menggunakan TSOP 1738. Penggunaan lampu LED RGB ini dilengkapi dengan LDR (Light Dependent Resistor untuk otomatisasi lampu pada waktu malam dan pagi hari, sedangkan untuk processornya menggunakan arduino duemilanove. Sebagai sumber tegangan menggunakan battery 12V yang dilengkapi dengan solar cell untuk charger battery. Penggunaan lampu LED RGB( Light Emiting Dioda Red, Green, Blue dapat menerima sinyal dari remote dengan jarak 10 meter dan dapat memancarkan cahaya berwarna merah, biru, hijau, dan kombinasinya. Di waktu malam hari lampu ini dapat langsung menyala dan mati di waktu pagi hari. Lampu LED RGB ini dilengkapi dengan solar cell yang digunakan untuk mencharger aki/battery yang berfungsi sebagai power supply ke board arduino. 

  13. Implementation of PIC Based LED Displays

    OpenAIRE

    Htet Htet Thit San; Chaw Myat Nwe; Hla Myo Tun

    2014-01-01

    This paper explains the project which is a special kind of LED Display Board for performing dance movement according to the rhythm of music. Nowadays, LED display boards are widely used in advertising and other applications. LED display boards can also be used indoors or outdoors. The objective of this system is to design a display panel by using several dozens of LED matrix display. The display pattern can desire to be changed easily and modified by the user. This LED display...

  14. Blue Angel for green electronics

    Energy Technology Data Exchange (ETDEWEB)

    Boettcher-Tiedemann, C.; Jacobs, B. [Federal Environmental Agency, Berlin (Germany)

    2004-07-01

    The Blue Angel was the first eco-label worldwide. It has been in existence for 26 years. For the last 12 years, modern electronic office and communications equipment has been among the products that are eligible for award of the Blue Angel. The Blue Angel eco-label is an important element of integrated product policy and is aimed towards environmentally sound product design. In addition, health aspects are increasingly being taken into account in criteria development. The use of the label gives innovative companies better market opportunities for products so labelled. For consumers and for purchasers in businesses and public administrations, it gives valuable guidance for product purchase. (orig.)

  15. Fluorescent silicon carbide materials for white LEDs and photovoltaics

    DEFF Research Database (Denmark)

    Syväjärvi, Mikael; Ou, Haiyan; Wellmann, Peter

    Energy efficient materials solutions will be key figures in progressive energy saving applications. We explore a materials growth concept of fluorescent wide bandgap semiconductors for white and infrared LEDs as well as solar cells. This is an emerging scientific field which has not previously been...... explored. The applications include a white LED for general lighting in which the conversion is based on the semiconductor instead of using phosphors. The result is an LED technology which does not need rare earth metals and has a pure white light. In efficient fluorescent materials, the absorption may be...... the luminescence appears in the infrared region in a broad range from 700 to 1100 nm. This potentially can be used to develop an infrared LED for de-icing in wind power and airplanes, or medical applications. Further on, a very efficient solar cell material can be investigated by studying the impurity...

  16. Optics designs for an innovative LED lamp family system

    Science.gov (United States)

    Weiss, Herbert; Muschaweck, Julius; Hadrath, Stefan; Kudaev, Sergey

    2011-10-01

    On the general lighting market of LED lamps for professional applications there are still mainly products for single purpose solutions existing. There is a lack of standardised lamp systems like they are common for conventional lighting technologies. Therefore, an LED lamp family system was studied using high power LED with the objective to entirely substitute standard conventional lamp families in general lighting applications in the professional market segment. This comprises the realization of sets of lamp types with compact and linear shapes as well as with light distribution characteristics ranging from diffuse to extreme collimation and exceptionally high candle power. Innovative secondary optics concepts are discussed which allow both, the design of lamps with non-bulky shape and to obtain sufficient colour mixing when using multicolour LED combinations in order to achieve a very high colour rendering quality.

  17. [Effects of different LED light qualities on growth, photosynthetic characteristics and nutritional quality of savoy].

    Science.gov (United States)

    Chen, Xiang-Wei; Liu, Shi-Qi; Wang, Yue; Liu, Jing-Kai; Feng, Lei

    2014-07-01

    LED lighting has several unique advantages over traditional lighting, including the ability to control spectral composition, the ability to produce very high light levels with low radiant heat output when cooled properly, and the ability to maintain useful light output for years without replacement. LED light sources have the capability of controlling true spectral composition, allowing wavelengths to match plant photoreceptors to provide more optimal production to regulate plant morphology and nutritional quality. In this paper, the effects of different light qualities on the growth, photosynthetic response and nutritional quality of savoy were studied. With 'Juhua-Xiaobaye' savoy as the test plant, full red light, full blue light, red/blue (3/1) light, red/blue (7/1) light and white/red/blue (3/2/1) light generated by light-emitting diodes were applied with white light generated by fluorescent lamps as control. The results showed that red light could increase biomass and stem diameter, but blue light showed the opposite effect. The chlorophyll (a+b) content was the highest in the red/blue (7/1) light treatment, and chlorophyll (a+b) content was correlated with the red/blue ratio positively. Blue light decreased chlorophyll (a + b) content of savoy, and increased chlorophyll a/b. The photosynthetic rate (Pn) and transpiration rate under red light were the highest, and increased by 43.8% and 55.1% compared with the control. Intercellular CO2 concentration and conductance were the highest under blue light. The fluorescence parameters of the plant were significantly affected by light quality. Values of the maximal photochemical efficiency of PS II (Fv/Fm), Fv/Fo and Phi(PS II) were the highest under white light. Soluble sugar, soluble protein and vitamin C contents were the highest under red, blue and white light, respectively. Comprehensive analysis indicated that red/blue (7/1) light was the best light combination to increase leaf chlorophyll (a+b) content and net

  18. Energy savings by implementation of light quality LED lighting. Final report; Implementering af energibesparelser ved benyttelse af hoejkvalitets LED belysning. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Hansen, C.; Thorseth, A.; Poulsen, Peter

    2010-03-15

    The project developed two new LED light sources and systems, emphasising the potential of LED technology for energy savings and lighting quality. A LED light source for display case lighting, replacing incandescent lamps, was successfully installed in the Treasury at Rosenborg Castle in Copenhagen, Denmark, and it was decided to extend the solution in 2010. Electricity savings of 74% were achieved. LED light sources replacing halogen bulbs in cooker hoods reduce electricity consumption by 69% and ensure even lighting of the entire working surface with about 500 lux at all cooking areas. Furthermore, a new LED optics system was patented. (ln)

  19. Removal of indigo blue using clinoptilolite-Fe

    International Nuclear Information System (INIS)

    The removal of indigo blue from aqueous solutions was evaluated using modified clinoptilolite with Fe (Z-Fe) which was characterized by SEM, EDS analysis and specific area (BET). The process followed the kinetics of pseudo-second order and Langmuir isotherm. Sorption capacity obtained was 18 mg g-1 and a solid-liquid ratio 10 g L-1. (Author)

  20. Color tunable LED spot lighting

    Science.gov (United States)

    Hoelen, C.; Ansems, J.; Deurenberg, P.; van Duijneveldt, W.; Peeters, M.; Steenbruggen, G.; Treurniet, T.; Valster, A.; ter Weeme, J. W.

    2006-08-01

    A new trend in illumination is to use dynamic light to set or dynamically vary the ambience of a room or office. For this we need color tunable spots that can reliably vary over at least a wide range of color temperatures, and preferably also more saturated colors. LEDs are in principle ideally suited for this application thanks to their nature of emitting light in a relatively narrow band. For color tunable spot lighting based on the concept of mixing RGB LED colors, the key results have been presented before. Limitations of these 3-intrinsic-color mixing systems with high color rendering properties are found in a limited operating temperature range due to wavelength shifts, a limited color temperature range, and a low maximum operating temperature due to a strong flux decrease with increasing temperature. To overcome these limitations, a 3-color R pcGB system with phosphor-converted red (R pc) and a 4-color RAGB system have been investigated. With both systems, a CRI of at least 80 can be maintained over the relevant color temperature range of approximately 2700 K to 6500 K. In this paper we compare these concepts on overall system aspects and report on the performance of prototype spot lamps. The main features of the RAGB and R pcGB spot lamp concepts can be summarized as: 1) The RAGB spot overcomes CRI and gamut shortcomings of RGB light sources and gives much freedom in wavelength selection, but suffers from temperature sensitivity and complex controls; 2) The R pcGB spot overcomes shortcomings concerning CRI and thermal dependence of RGB sources and enables relatively simple controls, but needs an improved overall red efficacy. With both color concepts, prototype spot lamps have been built. The amber to red emitting nitridosilicate-based phosphors can be wavelength-tuned for optimal performance, which is found at a peak emission around 610 nm for high color quality systems. This results in a simple and very robust system with good color consistency. For the

  1. Momentary adjusting methods for simulating the color temperature, hues and brightness of daylight illumination with RGB LEDs for indoor lighting.

    Science.gov (United States)

    Tsuei, Chih-Hsuan; Sun, Wen-Shing

    2011-07-01

    Methods for simulating the color temperature, hue and brightness of daylight illumination for indoor lighting simply by adjusting the intensity of red, green, and blue light emitting diodes are proposed. We obtain uniform color mixing with a light box by adjusting the ratios between the intensities of red, green and blue LEDs. The intensity can be found by measuring the CIE chromaticity coordinates (x, y) and the luminance Y of the daylight with a chroma meter. After the chromaticity coordinates (x, y) and the luminance Y are found, the tristimulus values can be calculated and then transferred to red, green, and blue primaries by linear transformation. With the correct ratio of red, green, and blue intensities, the color temperature, hues and brightness of daylight can be rebuilt by red, green, and blue light emitting diodes. PMID:21747561

  2. Karner Blue Butterfly Recovery Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This recovery plan has been prepared by the Karner Blue Butterfly Recovery Team under the leadership of Dr. David Andow, University of Minnesota-St. Paul. Dr. John...

  3. Enhanced biomass production and lipid accumulation of Picochlorum atomus using light-emitting diodes (LEDs).

    Science.gov (United States)

    Ra, Chae Hun; Kang, Chang-Han; Jung, Jang-Hyun; Jeong, Gwi-Taek; Kim, Sung-Koo

    2016-10-01

    The effects of light-emitting diode (LED) wavelength, light intensity, nitrate concentration, and time of exposure to different LED wavelength stresses in a two-phase culture on lipid production were evaluated in the microalga, Picochlorum atomus. The biomass produced by red LED light was higher than that produced by purple, blue, green, or yellow LED and fluorescent lights from first phase of two-phase culture. The highest lipid production of P. atomus was 50.3% (w/w) with green LED light at 2days of second phase as light stress. Fatty acid analysis of the microalgae showed that palmitic acid (C16:0) and linolenic acid (C18:3) accounted for 84-88% (w/w) of total fatty acids from P. atomus. The two-phase culture of P. atomus is suitable for biofuel production due to higher lipid productivity and favorable fatty acid composition. PMID:27474341

  4. The Blue Bottle Reaction as a General Chemistry Experiment on Reaction Mechanisms

    Science.gov (United States)

    Engerer, Steven C.; Cook, A. Gilbert

    1999-11-01

    A kinetics/reaction mechanism experiment using the classic blue bottle reaction is described. Using the scientific method (observe, question, hypothesize, experiment, repeat) students propose and test possible reaction mechanisms for the methylene blue-catalyzed oxidation of dextrose with its dramatic color change. Students are led to discover the three-step mechanism through a series of questions. An advanced version for honors lab courses is also suggested.

  5. LEDs light up the world

    Energy Technology Data Exchange (ETDEWEB)

    Mather, N.

    2004-06-30

    A lighting system using light-emitting diodes, and privately financed by a Canadian engineering professor at the University of Calgary, has been set up in a village in Nepal in 2000. Since then, through the efforts of the 'Light Up The World' Foundation, established by Dr. Irvine-Halliday, projects have lit up thousands of homes in the Philippines, India, Afghanistan, the Galapagos Islands, Mexico, Sri Lanka, and Angola. Although the goal of the project is primarily to provide lighting for reading and writing for school-children, the project has been the source of many other advantages; creation of enterprise, increased employment, enhanced income, gender equality, and improvements in health and safety among them. Since LED lamps in most cases replace kerosene lamps, the system also has significant environmental benefits. The system as originally envisioned creates electricity by pedal-powered generator, or by solar panels connected to a battery, depending on what is available at each home. Each home is connected to the power supply and supplied with low-energy diode lamps. The lights are extremely efficient and many homes can be equipped with them using less energy than it takes to power a single 100-watt light bulb. 5 photos.

  6. Blue Ocean vs. Five Forces

    OpenAIRE

    Burke, Andrew; Stel, André; Thurik, Roy

    2010-01-01

    textabstractThe article reports on the authors' research in the Netherlands which focused on a profit model in Dutch retail stores and a so-called blue-ocean approach which requires a new market that attracts consumers and increases profits. Topics include the competitive strategy approach to increasing profits. The authors conclude that the blue-ocean strategy or innovation approach is sustainable.

  7. Radiolysis of methylene blue studied by ESR. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Contineau, M.; Iliescu, C.; Ciureanu, M. (National Inst. of Chemistry, Bucharest (RoO). Dept. of Physical Chemistry)

    1983-05-31

    Electron spin resonance spectra have been used to gain information on the mechanism of radiolysis of aqueous solutions of methylene blue. The identity and behaviour of the semiquinone radicals formed as intermediate reduction products were discussed for strongly acid and for alcaline solutions. In order to obtain information on the radiolytic mechanism in strongly acidic media, irradiation was performed in the presence of various types of scavengers: sodium formate, glucose, succinic acid, hydroquinone and D,L-..cap alpha.. alanine.

  8. Oxidation of Methylene Blue in Aqueous Solutions with Streamer Plasmas%流光放电等离子体液相氧化降解亚甲基蓝

    Institute of Scientific and Technical Information of China (English)

    张祥龙; 王毅; 胡小吐

    2011-01-01

    We analyzed the constitution and performance characteristics of a pulse generator,especially,the structure design of rotating spark gap switch(RSGS),which is the key part that greatly favors electrical field distortion to recover the gap insulation strength for production of streamer,and is also beneficial to simplifying insulation design and prolonging the life of the switch,etc.Moreover,we studied the effects of the main parameters,such as peak voltage,discharge frequency,concentration,volume,air bubbling.Meanwhile,we adopted streamer discharge plasma to oxidize high concentration methylene blue in the liquid phase.The experimental results show that the degradation efficiency and energy density increase with peak voltage and pulse frequency.However,pollutant degradation rate of increase is less than the rate of increase of energy,which can indicate that energy efficiency of low-voltage is higher and consumption of free radical is consistent with the characteristics of the secondary compound.Meanwhile,the electrode style and mass transfer efficiency play important roles in oxidation process.%针对染料废水常规方法难降解等问题,通过使用自行研制的高压窄脉冲电源系统,试验分析了流光放电等离子体对染料污染物主要代表亚甲基蓝(MB)的处理效果。介绍了流光电源装置的构成及工作性能,核心元件八电极旋转火花隙开关(E-RSGS)的结构设计可产生电场畸变从而减少开关开断时间,有利于流光产生;同时延长开关寿命,简化开关绝缘设计。考察了液相流光放电条件下,脉冲电压峰值等因素对亚甲基蓝去除率的影响。实验结果表明:工业质量浓度范围内,提高峰值电压和放电频率可加大注入流光的能量密度,空气曝气量即空气体积流量的增大则增强

  9. Design of the control system for full-color LED display based on MSP430 MCU

    Science.gov (United States)

    Li, Xue; Xu, Hui-juan; Qin, Ling-ling; Zheng, Long-jiang

    2013-08-01

    The LED display incorporate the micro electronic technique, computer technology and information processing as a whole, it becomes the most preponderant of a new generation of display media with the advantages of bright in color, high dynamic range, high brightness and long operating life, etc. The LED display has been widely used in the bank, securities trading, highway signs, airport and advertising, etc. According to the display color, the LED display screen is divided into monochrome screen, double color display and full color display. With the diversification of the LED display's color and the ceaseless rise of the display demands, the LED display's drive circuit and control technology also get the corresponding progress and development. The earliest monochrome screen just displaying Chinese characters, simple character or digital, so the requirements of the controller are relatively low. With the widely used of the double color LED display, the performance of its controller will also increase. In recent years, the full color LED display with three primary colors of red, green, blue and grayscale display effect has been highly attention with its rich and colorful display effect. Every true color pixel includes three son pixels of red, green, blue, using the space colour mixture to realize the multicolor. The dynamic scanning control system of LED full-color display is designed based on MSP430 microcontroller technology of the low power consumption. The gray control technology of this system used the new method of pulse width modulation (PWM) and 19 games show principle are combining. This method in meet 256 level grayscale display conditions, improves the efficiency of the LED light device, and enhances the administrative levels feels of the image. Drive circuit used 1/8 scanning constant current drive mode, and make full use of the single chip microcomputer I/O mouth resources to complete the control. The system supports text, pictures display of 256 grayscale

  10. Control of burn wound sepsis in rats by methylene blue-mediated photodynamic treatment

    Science.gov (United States)

    Hasegawa, Hiroyuki; Sato, Shunichi; Kawauchi, Satoko; Saitoh, Daizoh; Shinomiya, Nariyoshi; Ashida, Hiroshi; Terakawa, Mitsuhiro

    2012-02-01

    Control of wound sepsis is an important challenge in traumatology. However, increase in the drug-resistant bacteria makes this challenge considerably difficult in recent years. In this study, we attempted to control burn wound sepsis in rats by photodynamic treatment, which has been reported to be effective against some drug-resistant bacteria. A 20% TBSA (total body surface area) full-thickness burn was made in rat dorsal skin, and five days after injury, a suspension of P. aeruginosa was applied to the wound surface. At 30 min after infection, a methylene blue (MB) solution was applied to the wound surface; 5 min afterwards, the wound was illuminated with a 665-nm light emitting diode (LED) array for 10 min. This treatment (application of MB and illumination) was repeated 3 times successively. The averaged light intensity on the wound surface was 3.3 mW/cm2, the corresponding total light dose being 5.9 J/cm2. One week after injury, the numbers of bacteria in the blood and liver were counted by colony forming assay. In the liver, the number of bacteria of the treated group was significantly lower than that of the sham control group without photodynamic treatment. In the blood, no bacteria were detected in the treated group, while a certain amount of bacteria was detected in the control group. These results demonstrate the efficacy of MB-mediated PDT with a red LED array to control burn wound sepsis.

  11. Fluorescent Carbon Quantum Dots as Single Light Converter for White LEDs

    Science.gov (United States)

    Feng, Xiaoting; Zhang, Feng; Wang, Yaling; Zhang, Yi; Yang, Yongzhen; Liu, Xuguang

    2016-06-01

    Synthesis of fluorescent carbon quantum dots (CQDs) as single light converter and their application in white light-emitting diodes (LEDs) are reported. CQDs were prepared by a one-step hydrothermal method using glucose and polyethylene glycol 200 as precursors. The structural and optical properties of the CQDs were investigated. The CQDs with uniform size of 4 nm possessed typical excitation-dependent emission wavelength and quantum yield of 3.5%. Under ultraviolet illumination, the CQDs in deionized water emitted bright blue fluorescence and produced broad visible-light emission with high red, green, and blue spectral component ratio of 63.5% (red-to-blue intensity to total intensity), suggesting great potential as single light converter for white LEDs. To demonstrate their potential, a white LED using CQDs as a single light converter was built. The device exhibited cool white light with corresponding color temperature of 5584 K and color coordinates of (0.32, 0.37), belonging to the white gamut. This research suggests that CQDs could be a promising candidate single light converter for white LEDs.

  12. Fokusgruppeinterview som led i en evalueringsproces

    DEFF Research Database (Denmark)

    Andersen-Mølgaard, Hanna; Harrit, Ole

    2006-01-01

    Teoretiske begrundelser og perspektiver, responsiv-konstruktivistisk evaluering, fokusgruppeinterview som led i BIKVAmodellen, eksempler, vurdering og perspektivering......Teoretiske begrundelser og perspektiver, responsiv-konstruktivistisk evaluering, fokusgruppeinterview som led i BIKVAmodellen, eksempler, vurdering og perspektivering...

  13. Goniometric characterization of LED based greenhouse lighting

    DEFF Research Database (Denmark)

    Thorseth, Anders; Lindén, Johannes; Corell, Dennis Dan;

    2015-01-01

    This paper describes a demonstration of goniospectroradiometry for characterizations of new light emitting diode (LED) based luminaries for enhanced photosynthesis in greenhouses. It highlights the differences between measurement of the traditional high pressure sodium (HPS) luminaries and the LED...... based luminaries. The LED based luminaries are compared to traditional HPS luminaries; in terms of energy efficiency with regard to the photosynthetic photon flux, and the LED luminaries were found to be more effective than the HPS luminaries...

  14. Thermal Design for 5 Watt Power LED

    Institute of Scientific and Technical Information of China (English)

    WANG Cai-feng; NIU Ping-juan; GAO Tie-cheng; YANG Guang-hua; FU Xian-song

    2009-01-01

    With the consideration of the thermal management and heat sink requirements, a cooling device is designed and the thermal resistance of this device is calculated with a single 5 W power LED. The thermal design of a single 5 W power LED is reasonable, effective and the result has been simulated. This design also instruct other power LEDs' thermal design. Provided is a reliable and effective method for the design of power LED illumination lamps and lanterns.

  15. LED Traffic Light as Communication Device

    OpenAIRE

    Kwan, TO; Chan, CH; Liu, HS; Pang, GKH

    1999-01-01

    The visible light from an LED (light emitting diode) traffic light can be modulated and encoded with information. Hence, it can be used for the broadcasting of audio messages or any traffic or road information. Essentially all LED traffic lights can be used as communications devices. The paper focuses on the description of an audio information system made up of high brightness, visible light emitting diodes (LEDs) in which one or more LEDs are modulated and encoded with audio messages. The sy...

  16. Dual use of LED traffic signal system

    OpenAIRE

    Cheung, SW; Yang, ES; Tam, YY; Man, CW; D. Yang

    1999-01-01

    The dual use, signaling and communication, of LED traffic signal system is described and analyzed. The primary function of a traffic light system is to give traffic and pedestrian signals. A prototype of LED traffic signal head is developed to perform a secondary function: communication. A wireless communication link is set up using the LED traffic signal head as the transmitter. The LEDs are modulated to transmit information-carrying light. The receiver uses a silicon photodiode to detect th...

  17. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products Part 2: LED Manufacturing and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Scholand, Michael; Dillon, Heather E.

    2012-05-01

    Part 2 of the project (this report) uses the conclusions from Part 1 as a point of departure to focus on two objectives: producing a more detailed and conservative assessment of the manufacturing process and providing a comparative LCA with other lighting products based on the improved manufacturing analysis and taking into consideration a wider range of environmental impacts. In this study, we first analyzed the manufacturing process for a white-light LED (based on a sapphire-substrate, blue-light, gallium-nitride LED pumping a yellow phosphor), to understand the impacts of the manufacturing process. We then conducted a comparative LCA, looking at the impacts associated with the Philips Master LEDbulb and comparing those to a CFL and an incandescent lamp. The comparison took into account the Philips Master LEDbulb as it is now in 2012 and then projected forward what it might be in 2017, accounting for some of the anticipated improvements in LED manufacturing, performance and driver electronics.

  18. Sediment balances in the Blue Nile River Basin

    Institute of Scientific and Technical Information of China (English)

    Yasir SAALI; Alessandra CROSATO; Yasir AMOHAMED; Seifeldin HABDALLA; Nigel GWRIGHT

    2014-01-01

    Rapid population growth in the upper Blue Nile basin has led to fast land-use changes from natural forest to agricultural land. This resulted in speeding up the soil erosion process in the highlands and increasing sedimentation further downstream in reservoirs and irrigation canals. At present, several dams are planned across the Blue Nile River in Ethiopia and the Grand Ethiopian Renaissance Dam is currently under construction near the border with Sudan. This will be the largest hydroelectric power plant in Africa. The objective of this paper is to quantify the river flows and sediment loads along the Blue Nile River network. The Soil and Water Assessment Tool was used to estimate the water flows from un-gauged sub-basins. To assess model performance, the estimated sediment loads were compared to the measured ones at selected locations. For the gauged sub-basins, water flows and sediment loads were derived from the available flow and sediment data. To fill in knowledge gaps, this study included a field survey in which new data on suspended solids and flow discharge were collected along the Blue Nile and on a number of tributaries. The comparison between the results of this study and previous estimates of the sediment load of the Blue Nile River at El Deim, near the Ethiopian Sudanese border, show that the sediment budgets have the right order of magnitude, although some uncertainties remain. This gives confidence in the results of this study providing the first sediment balance of the entire Blue Nile catchment at the sub-basin scale.

  19. Phosphors for near UV-Emitting LED's for Efficacious Generation of White Light

    Energy Technology Data Exchange (ETDEWEB)

    McKittrick, Joanna

    2013-09-30

    1) We studied phosphors for near-UV (nUV) LED application as an alternative to blue LEDs currently being used in SSL systems. We have shown that nUV light sources could be very efficient at high current and will have significantly less binning at both the chip and phosphor levels. We identified phosphor blends that could yield 4100K lamps with a CRI of approximately 80 and LPWnUV,opt equal to 179 for the best performing phosphor blend. Considering the fact that the lamps were not optimized for light coupling, the results are quite impressive. The main bottleneck is an optimum blue phosphor with a peak near 440 nm with a full width half maximum of about 25 nm and a quantum efficiency of >95%. Unfortunately, that may be a very difficult task when we want to excite a phosphor at ~400 nm with a very small margin for Stokes shift. Another way is to have all the phosphors in the blend having the excitation peak at 400 nm or slightly shorter wavelength. This could lead to a white light source with no body color and optimum efficacy due to no self-absorption effects by phosphors in the blend. This is even harder than finding an ideal blue phosphor, but not necessarily impossible. 2) With the phosphor blends identified, light sources using nUV LEDs at high current could be designed with comparable efficacy to those using blue LEDs. It will allow us to design light sources with multiple wattages using the same chips and phosphor blends simply by varying the input current. In the case of blue LEDs, this is not currently possible because varying the current will lower the efficacy at high current and alter the color point. With improvement of phosphor blends, control over CRI could improve. Less binning at the chip level and also at the phosphor blend level could reduce the cost of SSL light sources. 3) This study provided a deeper understanding of phosphor characteristics needed for LEDs in general and nUV LEDs in particular. Two students received Ph.D. degrees and three

  20. Fabrication of dual colour LEDs for OSL dosimetry readers

    International Nuclear Information System (INIS)

    In OSL the defects are stimulated by the light in the visible/IR region and as a result, release of either the electron or hole and subsequent capture at the recombination centre leads to emission of radiation which is generally at shorter wavelength compared to the wavelength of the stimulating radiation. Both the stimulation and emission spectra are characteristic of the phosphor. Blue excitation is needed for phosphors like Al2O3:C, BeO and LiMgPO4:Tb, green excitation for MgO:Tb, Y2SiO5, Porcelain red for KBr:Eu and IR excitation for feldspar. Even for Al2O3:C some workers prefer green excitation over blue. Hence, a versatile OSL reader should incorporate a variety of excitation sources. Usually, separate optical paths are chosen for different excitation sources which are located at separate physical locations. This makes design of OSL reader rather complicated. We propose use of dual colour LED sources to tackle this problem

  1. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants;Adsorcion de colorantes azul vegetal y azul acuarela por zeolitas naturales modificadas con surfactantes

    Energy Technology Data Exchange (ETDEWEB)

    Jardon S, C. C.; Olguin G, M. T. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Diaz N, M. C., E-mail: teresa.olguin@inin.gob.m [Instituto Tecnologico de Toluca, Av. Instituto Tecnologico s/n, Ex-Rancho la Virgen, 52140 Metepec, Estado de Mexico (Mexico)

    2009-07-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  2. Adsorption Behavior of Reactive Turquoise Blue KN-G in Aqueous Solutions on a Novel Spherical Lignin-based Adsorbent%水溶液中的活性翠兰KN-G在一种新型球形木质素吸附剂上吸附特性研究

    Institute of Scientific and Technical Information of China (English)

    刘明华; 洪树楠; 黄建辉; 叶庆; 刘千钧

    2005-01-01

    A novel spherical lignin-based adsorbent, denoted as SLBA, was prepared using alkali lignin as a raw material which was provided by a masson pine pulp mill in Fujian, China. Then an investigation was conducted regarding the adsorption behavior of a reactive dye (Turquoise Blue KN-G) from aqueous solutions with the above new spherical lignin-based adsorbent containing the quaternary ammonium cationic group. Moreover, various affecting factors on the adsorption were optimized. It was found that the adsorption of reactive Turquoise Blue KN-G on the adsorbent was found to be initially pH and concentration dependent. The concentration helped to increase the equilibrium adsorption capacity. With an increase in solution pH ranging from 3 to 8, the removal percentage increased sharply from 12.3 % to 98.6 %, and at pH=10, the removal rate reached 100%. The adsorption process followed the Langmuir adsorption isotherm,i.e.,Ce/qe=0.0002136+0.001225Ce.Moreover,RL, a dimensionless separation factor of an equilibrium parameter, was 8.711×10 -4, which was far less than 0.1 indicating the favorable adsorption. The saturated adsorption capacity was 816.3 mg/g, and the total breakthrough removal capacity was 761 mg/g, which prevailed over the commercial activated carbons evidently. The reactive Turquoise Blue KN-G adsorbed on SLBA could be recovered with a mixture of alcohol, dicyandiamide-formaldehyde polycondensate and HCl aqueous solutions. And, the maximum desorption efficiency could reach 98.7%.%以马尾松浆厂提供的碱木素为原料研制出一种新型的球形木质素吸附剂SLBA.然后以活性翠兰KN-G为吸附质研究其在这种含有季铵基团的球形木质素吸附剂上的吸附特性.并进行吸附影响因素的优选实验.实验结果表明:活性翠兰KN-G在吸附剂上的吸附效果取决于吸附质溶液的pH值和吸附质的初始浓度.初始浓度的增大有利于提高平衡吸附容量.在3~8的pH范围内,去除率从12.3%

  3. Led-valaistuksen soveltuvuus merentutkimusalus Arandalle

    OpenAIRE

    Vesterinen, Elina

    2015-01-01

    Opinnäytetyön tavoitteena oli selvittää led-valaistuksen soveltuvuutta merentutki-musalus Arandalle, sekä laivaolosuhteisiin yleisesti. Työssä selvitettiin led-valaistuksen mahdollisia energian säästöjä Arandan tämänhetkiseen valaistukseen verrattuna ja tarkasteltiin led-valaistuksen hyviä ja huonoja ominaisuuksia. Sekä led-valaistuksen ominaisuuksien, että luokituslaitosten säädösten perusteella pyrittiin arviomaan led-valaistuksen yleistä soveltuvuutta laivaolosuhteisiin. Lähdeainei...

  4. A comparative study of blue, green and yellow light emitting diode structures grown by metal organic chemical vapor deposition

    Science.gov (United States)

    Ramaiah, Kodigala Subba; Su, Y. K.; Chang, S. J.; Chen, C. H.

    2006-02-01

    The blue, green and yellow light emitting diode (LED) structures have been fabricated by metal organic chemical vapor deposition (MOCVD), and characterized by using different techniques, in order to understand the mechanism between these LEDs. Atomic force microscopy (AFM) analysis revealed that the surface roughness value and density of etch pits were different in the blue, green and yellow LEDs. The threading, misfit dislocations, interfacial dislocations, nano-pipe-like structures and quantum dot-like structures, which determine quality of the structures, were observed by transmission electron microscope (TEM) in the LED structures. The reasons for their formation in the layers are now elucidated. The indium composition, period width such as well and barrier widths were determined by simulating experimental high resolution X-ray diffraction (HRXRD) spectra. The In composition obtained by HRXRD and photoluminescence (PL) measurements for the same LED structure was not one and the same due to several reasons. In fact, the InGaN quantum well emission peaks at 2.667 and 2.544 eV of the blue and green LEDs, respectively showed S-shaped character shift, whereas the quantum well peak at 2.219 eV of yellow LEDs did not show any shift in the PL spectra with decreasing temperature. The blue, green and yellow LEDs showed different activation energies.

  5. Alanine/ Bromophenol Blue Polymeric Films For Radiation Dosimetry Applications

    International Nuclear Information System (INIS)

    The Polymeric dyed flexible films are considered to be the most commonly used dosimeters for routine dose monitoring in ionizing-radiation processing. Dyed polymer films prepared by simple technique of casting aqueous solution of poly (vinyl alcohol) containing bromophenol blue on horizontal glass plate are useful for high dose dosimetry. Different concentrations of L-alanine were added in presence of bromophenol blue mixed inside PVA films producing a blue film. The color has a variable absorbance with applied dose in the range from 1-35 kGy. Spectrophotometric evaluation at 602 nm for the absorbance intensity of this color was investigated as a function of dose. The used work method is uncomplicated and very easy for routine application. The radiation chemical yield G (value) was calculated in the presence and absence of alanine. Humidity during irradiation was also studied. These films show a good stability before and after irradiation under different storage conditions

  6. Plant growth with Led lighting systems

    International Nuclear Information System (INIS)

    Leds lighting is highly relevant for the horticultural industry. Compared to other light sources used for plant production, leds have several properties which are potentially useful in relation to horticulture. However, although LEDs technology has raised strong interest in research for extraterrestrial agriculture, current LEDs panel costs are still too high for commercial adoption in greenhouse sector, and their electrical efficacies do not compete with those of high-pressure sodium lamps, but several manufactures are working to address these issues. When LEDs become practical, their ability to based light sources specifically suitable for photosynthesis and other horticulturally relevant plant properties (i.e. low radiated heat; lighting from within the canopy) will render the narrow band spectrum of LEDs of particular interest for providing light to greenhouse horticulture. A general description of LEDs application and their technical characteristics is briefly reported.

  7. Methylene blue related sterile endophthalmitis.

    Science.gov (United States)

    Lim, A K E; Ulagantheran V, V; Siow, Y C; Lim, K S

    2008-08-01

    To report a case of methylene blue related endophthalmitis. Observational case report. Review of clinical record, photographs. A 60 year old man developed endophthalmitis after methylene blue was accidentally used to stain the anterior capsule during phacoemulsification of cataract. His left visual acuity deteriorated from 6/12 to 6/36 two weeks after the operation. Despite intensive treatment with topical and intravitreal antibiotics, his condition deteriorated. A vitrectomy and silicone oil injection eventually managed to control the progression of the disease and salvage the eye. However the visual outcome remained poor due to corneal decompensation and retinal ischemia. Both vitreous tap and vitreous biopsy were negative for any organism. Methylene blue is extremely toxic to ocular structures and should not be used intraocularly. PMID:19248701

  8. Implementation of PIC Based LED Displays

    Directory of Open Access Journals (Sweden)

    Htet Htet Thit San

    2014-09-01

    Full Text Available This paper explains the project which is a special kind of LED Display Board for performing dance movement according to the rhythm of music. Nowadays, LED display boards are widely used in advertising and other applications. LED display boards can also be used indoors or outdoors. The objective of this system is to design a display panel by using several dozens of LED matrix display. The display pattern can desire to be changed easily and modified by the user. This LED display board is overall in two major components; which are the microcontroller and LED display panel. Microcontrollers with programs are developed to generate characters and graphics for this module. In this system, when the LED display board is “ON”, it will display the messages and then dance movements by the rhythm of music using a PIC microcontroller. It is not needed to change the LED panel, only to change the input data in PIC program. In this system, LED panel is controlled by a program in microcontroller from serial to parallel shift registers using the scanning method. PIC microcontroller is for generating the output signal to output display board by using a program. Then, it will be run on the LED display board. This is very useful in area like railway platforms, streets, banks, training institutes and other applications to show data information on the large LED boards. As a result, this LED display board is useful as indoors or outdoors as it is also economic. This display consists of maximum 72 bright LEDs which are rotated to show the display. In this system, this display can show data information which will require a whopping 512 LEDs. Therefore hardware and cost minimization is achieved. PIC Basic Pro programming language will be used in PIC microcontroller. The simulation result will be tested with Proteus 8 Electronic Simulation Software.

  9. The blue-collar brain.

    Science.gov (United States)

    Van Orden, Guy; Hollis, Geoff; Wallot, Sebastian

    2012-01-01

    Much effort has gone into elucidating control of the body by the brain, less so the role of the body in controlling the brain. This essay develops the idea that the brain does a great deal of work in the service of behavior that is controlled by the body, a blue-collar role compared to the white-collar control exercised by the body. The argument that supports a blue-collar role for the brain is also consistent with recent discoveries clarifying the white-collar role of synergies across the body's tensegrity structure, and the evidence of critical phenomena in brain and behavior. PMID:22719730

  10. Testing Finance-Led, Export-Led and Import-Led Growth Hypotheses on Four Sub-Saharan African Economies

    OpenAIRE

    Evans, Olaniyi

    2013-01-01

    This study carries out an empirical examination of the finance-led, export-led and import-led growth hypothesis for four of the largest Sub-Saharan African economies namely South Africa, Nigeria, Ghana and Kenya. Within a multivariate Vector-Auto Regressive (VAR) framework, the concept of Granger causality is employed to determine the direction of causation between exports and output, duly taking into account the stationarity properties of the time series data. With further substantiation fro...

  11. LED背光源前景看好%There's an LED Backlight in Your Future

    Institute of Scientific and Technical Information of China (English)

    Steve Sechrist

    2006-01-01

    @@ LED backlight solution provider Global Lighting Technologies (GLT) (Brecksville, OH) is going to introduce a new family of LED light guides with plans to demonstrate a 24"(61 cm) LCD-TV with an LED backlight.To understand the significance of this announcement, we have to go back to a presentation given last month at the Strategies in Light (SIL) Conference held in San Francisco. There, Seoul Semiconductor VP, Dr. Jae Jo Kim, listed low efficiency (high cost) as the number one obstacle to large LCD adoption of LED lighting particularly, the number of LEDs required to adequately replace today's cold-cathode fluorescent lamps (CCFLs).

  12. Multichip on Aluminum Metal Plate Technology for High Power LED Packaging

    Institute of Scientific and Technical Information of China (English)

    Choong-mo NAM; Mi-hee JI

    2010-01-01

    Multichip on Aluminum Metal Plate(MOAMP) technology with simple structure and low thermal resistance is developed for effective heat removal of Light Emitting Diode(LED) p-n junction and LED lighting module to have high reliability. The thermal resistance of LED modules was numerical and experimental. Thermal resistance from the junction to aluminum metal plate, considering input power of LED module using MOAMP technology, is 3.02 K/W, 3.23 K/W for the measured and calculated, respectively. We expect that the reported MOAMP technology with low thermal resistance will be a promising solution for high power LED lighting modules.

  13. Effective optimization and analysis of white LED properties by using nano-honeycomb patterned phosphor film.

    Science.gov (United States)

    Lin, Huang-Yu; Wang, Sheng-Wen; Lin, Chien-Chung; Tu, Zong-Yi; Lee, Po-Tsung; Chen, Huang-Ming; Kuo, Hao-Chung

    2016-08-22

    This study presents an approach for patterning a polydimethylsiloxane (PDMS) phosphor film with a photonic crystal nano-honeycomb structure on a blue chip package. A phosphor film with a nano-honeycomb structure was patterned and transferred using a nanosphere and used for fabricating remote white light-emitting diodes (w-LEDs). The angular correlated color temperature deviation of the remote phosphor LED could be improved by varying nano-honeycomb structure pitches (450, 750, and 1150 nm). In particular, w-LED samples with excellent color uniformity (ΔCCT ranging from 940 to 440 K) were fabricated from 750-nm w-LED samples with nano-honeycomb-patterned tops. PMID:27557183

  14. Phosphor-converted LEDs with low circadian action for outdoor lighting.

    Science.gov (United States)

    Zabiliūtė, Akvilė; Vaicekauskas, Rimantas; Vitta, Pranciškus; Zukauskas, Artūras

    2014-02-01

    Dichromatic phosphor-converted (pc) light-emitting diodes (LEDs) with low circadian action are proposed for low-luminance photobiologically safe outdoor illumination. The LEDs feature the partial conversion of blue radiation in an orange phosphor with the resulting correlated color temperature in the "firelight" range of 1700-2500 K. The circadian action factor, which is the ratio of the biological efficacy of radiation due to the excitation of intrinsically photosensitive retinal ganglion cells to the mesopic luminous efficacy of radiation, is considerably lower than that of commercial white pc LEDs. The equivalent general color-rendering index estimated with regard to the reduced color-discrimination ability of human vision at low luminances has appropriate values in between those of common white pc LEDs and high-pressure sodium lamp. PMID:24487866

  15. A Color LED Driver Implemented by the Active Clamp Forward Converter

    Directory of Open Access Journals (Sweden)

    C. H. Chang

    2013-03-01

    Full Text Available Because light emitting diodes (LEDs have the advantages of dc working voltage, high luminescent efficiency, shortignition time, high reliability and pollution free, they have substituted for incandescent bulbs and fluorescent lampsgradually. In order to simplify circuit complexity, an active clamp forward converter with the sequential color display(SCD control is proposed to drive red, green and blue (RGB LED arrays. The proposed converter has zero-voltageswitching (ZVS operations of both the main switch and the auxiliary switch, resulting in high system efficiency. DrivingRGB LED arrays sequentially by one converter can save components and reduce cost significantly. Additionally, thepulse-width modulation (PWM control is applied to achieve a large chromaticity variation. The circuit operations areanalyzed in detail and the circuit parameters are designed based on the practical considerations. Finally, an illustrativeexample is implemented to demonstrate the feasibility and validity of the proposed LED driver.

  16. Fabrication of LED full-color display matrix with small pixel

    Science.gov (United States)

    Li, Jing; Xue, Bin; Yang, Hua; Liu, Lili; Xie, Haizhong; Pei, Yanrong; Lu, Pengzhi; Wang, Guohong; Wang, Junxi; Li, Jinmin

    2015-09-01

    With the development in material growth, device fabrication and packaging of LEDs, emission spectral of LED is able to cover the visible spectrum. In addition to the well-known lighting applications of LED, display is also one of the important applications of LED. In contrast with LCD, LEDs display has better contrast ratio, higher response rate, etc., which makes LEDs along with other self-illumination technologies an ideal candidate in making display panel. With the popularization of HD and Ultra HD standard, display panel with better image quality is needed. The number of pixels of the panel needs to be increased and the size of each pixel needs to be minimized. In this paper, we prepared a LED full-color display panel based on a 32×32 LED matrix with typical pixel size of 0.5mm. LED full-color display array with small pixel was obtained by mounting red LEDs, green LEDs and blue LEDs directly onto an isolating substrate such as sapphire . In addition, the substrate has metalized pads and connection before the matrix was connected to control unit. The control line and the column data line are prepared on the substrate, and there is an effective electrical insulation layers between them. The isolation layers consists of a SiO2 layer of 1000nm and polyimide layer of 3000nm. Polyimide as an important electrical insulating layer, we study some properties of it, such as :PI amination rate as a function of the curing temperature, PI resistivity as a function of the curing temperature and the punction electric field intensity of PI as a function of the film thickness of PI.

  17. Thermal, optical, and electrical engineering of an innovative tunable white LED light engine

    Science.gov (United States)

    Trivellin, Nicola; Meneghini, Matteo; Ferretti, Marco; Barbisan, Diego; Dal Lago, Matteo; Meneghesso, Gaudenzio; Zanoni, Enrico

    2014-02-01

    Color temperature, intensity and blue spectrum of the light affects the ganglion receptors in human brain stimulating the human nervous system. With this work we review different methods for obtaining tunable light emission spectra and propose an innovative white LED lighting system. By an in depth study of the thermal, electrical and optical characteristics of GaN and GaP based compound semiconductors for optoelectronics a specific tunable spectra has been designed. The proposed tunable white LED system is able to achieve high CRI (above 95) in a large CCT range (3000 - 5000K).

  18. NO2 measurements in Hong Kong using LED based long path differential optical absorption spectroscopy

    OpenAIRE

    Chan, K. L.; Pöhler, D.; G. Kuhlmann; Hartl, A.; Platt, U.; M. O. Wenig

    2012-01-01

    In this study we present the first long term measurements of atmospheric nitrogen dioxide (NO2) using a LED based Long Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument. This instrument is measuring continuously in Hong Kong since December 2009, first in a setup with a 550 m absorption path and then with a 3820 m path at about 30 m to 50 m above street level. The instrument is using a high power blue light LED with peak intensity at 450 nm coupled into t...

  19. Mapping the formation areas of giant molybdenum blue clusters: a spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Botar, Bogdan; Ellern, Arkady; Kogerler, Paul

    2012-05-18

    The self-assembly of soluble molybdenum blue species from simple molybdate solutions has primarily been associated with giant mixed-valent wheel-shaped cluster anions, derived from the {MoV/VI154/176} archetypes, and a {MoV/VI368} lemon-shaped cluster. The combined use of Raman spectroscopy and kinetic precipitation as self-assembly monitoring techniques and single-crystal X-ray diffraction is key to mapping the realm of molybdenum blue species by establishing spherical {MoV/VI102}-type Keplerates as an important giant molybdenum blue-type species. We additionally rationalize the empirical effect of reducing agent concentration on the formation of all three relevant skeletal types: wheel, lemon and spheres. Whereas both wheels and the lemon-shaped {MoV/VI368} cluster are obtained from weakly reduced molybdenum blue solutions, considerably higher reduced solutions lead to {MoV/VI102}-type Keplerates.

  20. Evaluation of Blue Value in different plant materials as a tool for rapid starch determination

    OpenAIRE

    Bogusław Samotus; Joanna Tuz; Elżbieta Doerre

    2014-01-01

    In order to determine the concentration of starch in plant materials from the intensity of the blue iodine complex, it is necessary to know the Blue Value (B.V.), which is defined in this paper as the absorbancy of 100 mg of a starch-iodine complex in 100 ml of aqueous solution. An adequate amount of plant material is treated with a hot CaCl2 solution for 1/2 hour and the solute is diluted to 25 ml with CaCl2. This basic solution serves to measure absorbancy, as well as for starch determinati...

  1. POSSIBILITIES OF LOCAL ECONOMIC DEVELOPMENT (LED) IN LAGGING RURAL AREAS

    OpenAIRE

    Ritter, Krisztián

    2014-01-01

    The long-term strategic objectives of the EU Rural Development Policy in the next (2014-2020) programming period are as follows: the competitiveness of agriculture, the sustainable management of natural resources and the balanced territorial development. In this strategy agriculture seems to remain one of the key element as solution for lagging rural areas. However parallel to the decreasing role of agriculture in employment, searching for the possibilities of local economic development (LED)...

  2. System Reliability for LED-Based Products

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J Lynn; Mills, Karmann; Lamvik, Michael; Yaga, Robert; Shepherd, Sarah D; Bittle, James; Baldasaro, Nick; Solano, Eric; Bobashev, Georgiy; Johnson, Cortina; Evans, Amy

    2014-04-07

    Results from accelerated life tests (ALT) on mass-produced commercially available 6” downlights are reported along with results from commercial LEDs. The luminaires capture many of the design features found in modern luminaires. In general, a systems perspective is required to understand the reliability of these devices since LED failure is rare. In contrast, components such as drivers, lenses, and reflector are more likely to impact luminaire reliability than LEDs.

  3. LEDs for general and horticultural lighting

    OpenAIRE

    Girón González, Emilio

    2012-01-01

    The work begins with an introductory part about Light Emitting Diode (or LEDs) and how these devices work. This report also shows an overview of different artificial light sources such as incandescent lamps, fluorescents tube and high-intensity discharge (HID) lamps. The LED lighting is more energy-efficient than other artificial lighting, since they require less energy to operate. The following part of the work reports LEDs for General Lighting that describes some basic concepts such as spec...

  4. Wide reflected angle DBR red light LED

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The coupled DBR LED with one DBR for reflecting normal incidence light and the other for reflecting inclined incidence light has been grown by MOCVD. For improving the conventional DBR which was used to increase light extraction efficiency in A1GaInP red light LED is analyzed. At 20 mA Dc injection current, the LED peak wave length is 630 nm, and the light intensity of on axis is 137 mcd. The output light power is 2.32 mW. The light intensity and output light power have been improved compared with the conventional LEDs.

  5. Flavour production of Stilton blue cheese microflora

    OpenAIRE

    Gkatzionis, Konstantinos

    2010-01-01

    In the blue cheese Stilton the starter mould Penicillium roqueforti grows and sporulates during the ripening period and is considered to be responsible for the unique blue cheese aroma. However, the sporulation of the mould, which results in the formation of blue veins, takes place in a fraction of the Stilton matrix which overall is very heterogeneous. Most blue cheeses develop a secondary microflora of yeasts which may affect their aroma. The aim of this study was to investigate the yeast f...

  6. LED illuminant on the ambient light

    Science.gov (United States)

    Liu, Anqing; Sandipan, Mishra; Shur, Michael

    2014-09-01

    We develop an approach for combining illuminance and spectral power distribution of the LED and ambient light and apply our technique for developing an LED camera flashlight balancing the illuminance contrast between object and background. Our method uses the closed loop, multiobjective optimization comprising: (1) characterizing the lighting task by illuminance, correlated color temperature (CCT), and statistical color quality indices that include a set of Statistical Color Quality Metrics and the Color Rendition Index (CRI) implemented with indexes of S (saturation) or D (dulling); (2) measuring the illuminance and the spectrum of the ambient light on the target lighting surface, which might depend on all the sources proving illumination and on the reflected light; (3) determining the desired illuminance of the LED source on the target lighting surface; (4) calculating the desired luminous flux of the LED source according to the desired illuminance; (5) constituting the SPD of the LED source; (6) calculating the relative spectra counts of the LED source and the ambient light on the target lighting surface (7) calculating the CCT and statistical color quality indexes of the combined light; (8) repeating the above steps until the resulting SPD is close enough to the expectation. Using the above method, an LED camera flashlight has been designed, which works together with usual fluorescent ambient light and generates working lighting environment with high fidelity and high CCT (6000K). The spectrum and luminous flux of the LED lamp is automatically tunable with a change of the ambient light.

  7. Led Zeppelin reklaamib Narvat / Anti Ronk

    Index Scriptorium Estoniae

    Ronk, Anti

    2007-01-01

    Ilmus Narva-teemaline kahest CD-st koosnev album, kus ühel plaadil on 60 minutit videot linna vaatamisväärsuste ja informatsiooniga, teisel - briti rockansambli Led Zeppelini teosed Narva sümfooniaorkestri ja rockansambli Led R esituses

  8. Reduced Component Count RGB LED Driver

    NARCIS (Netherlands)

    De Pedro, I.; Ackermann, B.

    2008-01-01

    The goal of this master thesis is to develop new drive and contrololutions, for creating white light from mixing the light of different-color LEDs, aiming at a reduced component count resulting in less space required by the electronics and lower cost. It evaluates the LED driver concept proposed in

  9. Led-licht biedt mogelijkheden in broeierij

    NARCIS (Netherlands)

    Neefjes, H.; PPO Bomen-bollen,

    2010-01-01

    Onderzoekers van PPO Lisse hebben de mogelijkheden van led-licht verkend bij met name lelie en tulp. Bij lelie bieden leds perspectief in de voortrek. Tulp kan er bijna de hele broeifase van profiteren. Veel licht is niet nodig, maar meerlagenteelt is een voorwaarde.

  10. In vitro and in vivo Efficacy of New Blue Light Emitting Diode Phototherapy Compared to Conventional Halogen Quartz Phototherapy for Neonatal Jaundice

    OpenAIRE

    Chang, Yun Sil; Hwang, Jong Hee; Kwon, Hyuk Nam; Choi, Chang Won; Ko, Sun Young; Park, Won Soon; Shin, Son Moon; Lee, Munhyang

    2005-01-01

    High intensity light emitting diodes (LEDs) are being studied as possible light sources for the phototherapy of neonatal jaundice, as they can emit high intensity light of narrow wavelength band in the blue region of the visible light spectrum corresponding to the spectrum of maximal bilirubin absorption. We developed a prototype blue gallium nitride LED phototherapy unit with high intensity, and compared its efficacy to commercially used halogen quartz phototherapy device by measuring both i...

  11. Advances in LEDs for automotive applications

    Science.gov (United States)

    Bhardwaj, Jy; Peddada, Rao; Spinger, Benno

    2016-03-01

    High power LEDs were introduced in automotive headlights in 2006-2007, for example as full LED headlights in the Audi R8 or low beam in Lexus. Since then, LED headlighting has become established in premium and volume automotive segments and beginning to enable new compact form factors such as distributed low beam and new functions such as adaptive driving beam. New generations of highly versatile high power LEDs are emerging to meet these application needs. In this paper, we will detail ongoing advances in LED technology that enable revolutionary styling, performance and adaptive control in automotive headlights. As the standards which govern the necessary lumens on the road are well established, increasing luminance enables not only more design freedom but also headlight cost reduction with space and weight saving through more compact optics. Adaptive headlighting is based on LED pixelation and requires high contrast, high luminance, smaller LEDs with high-packing density for pixelated Matrix Lighting sources. Matrix applications require an extremely tight tolerance on not only the X, Y placement accuracy, but also on the Z height of the LEDs given the precision optics used to image the LEDs onto the road. A new generation of chip scale packaged (CSP) LEDs based on Wafer Level Packaging (WLP) have been developed to meet these needs, offering a form factor less than 20% increase over the LED emitter surface footprint. These miniature LEDs are surface mount devices compatible with automated tools for L2 board direct attach (without the need for an interposer or L1 substrate), meeting the high position accuracy as well as the optical and thermal performance. To illustrate the versatility of the CSP LEDs, we will show the results of, firstly, a reflector-based distributed low beam using multiple individual cavities each with only 20mm height and secondly 3x4 to 3x28 Matrix arrays for adaptive full beam. Also a few key trends in rear lighting and impact on LED light

  12. 100 LPW 800 Lm Warm White LED

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Decai [Philips Lumileds Lighting Company, San Jose, CA (United States)

    2010-10-31

    An illumination grade warm white (WW) LED, having correlated color temperature (CCT) between 2800 K and 3500K and capable of producing 800 lm output at 100 lm/W, has been developed in this program. The high power WW LED is an ideal source for use as replacement for incandescent, and Halogen reflector and general purpose lamps of similar lumen value. Over the two year period, we have made following accomplishments: developed a high power warm white LED product and made over 50% improvements in light output and efficacy. The new high power WW LED product is a die on ceramic surface mountable LED package. It has four 1x1 mm{sup 2} InGaN pump dice flip chip attached to a ceramic submount in 2x2 array, covered by warm white phosphor ceramic platelets called Lumiramica and an overmolded silicone lens encapsulating the LED array. The performance goal was achieved through breakthroughs in following key areas: (1) High efficiency pump LED development through pump LED active region design and epi growth quality improvement (funded by internal programs). (2) Increase in injection efficiency (IE) represented by reduction in forward voltage (V{sub f}) through the improvement of the silver-based p-contact and a reduction in spreading resistance. The injection efficiency was increased from 80% at the start of the program to 96% at the end of the program at 700 mA/mm{sup 2}. (3) Improvement in thermal design as represented by reduction in thermal resistance from junction to case, through improvement of the die to submount connection in the thin film flip chip (TFFC) LED and choosing the submount material of high thermal conductivity. A thermal resistance of 1.72 K/W was demonstrated for the high power LED package. (4) Improvement in extraction efficiency from the LED package through improvement of InGaN die level and package level optical extraction efficiency improvement. (5) Improvement in phosphor system efficiency by improving the lumen equivalent (LE) and phosphor package

  13. An LED pulser for measuring photomultiplier linearity

    CERN Document Server

    Friend, M; Quinn, B

    2011-01-01

    A light-emitting diode (LED) pulser for testing the low-rate response of a photomultiplier tube (PMT) to scintillator-like pulses has been designed, developed, and implemented. This pulser is intended to simulate 80 ns full width at half maximum photon pulses over the dynamic range of the PMT, in order to precisely determine PMT linearity. This particular design has the advantage that, unlike many LED test rigs, it does not require the use of multiple calibrated LEDs, making it insensitive to LED gain drifts. Instead, a finite-difference measurement is made using two LEDs which need not be calibrated with respect to one another. These measurements give a better than 1% mapping of the response function, allowing for the testing and development of particularly linear PMT bases.

  14. An LED pulser for measuring photomultiplier linearity

    International Nuclear Information System (INIS)

    A light-emitting diode (LED) pulser for testing the low-rate response of a photomultiplier tube (PMT) to scintillator-like pulses has been designed, developed, and implemented. This pulser is intended to simulate 85 ns full width at half maximum photon pulses over the dynamic range of the PMT, in order to precisely determine PMT linearity. This particular design has the advantage that, unlike many LED test rigs, it does not require the use of multiple calibrated LEDs, making it insensitive to LED gain drifts. Instead, a finite-difference measurement is made using two LEDs which need not be calibrated with respect to one another. These measurements give a better than 1% mapping of the response function, allowing for the testing and development of particularly linear PMT bases. They also yield a functional form for the response of the PMT to a range of pulse sizes, which can be used in detector simulation.

  15. Using LEDs to reduce energy consumption

    Science.gov (United States)

    Eweni, Chukwuebuka E.

    The most popularly used light bulb in homes is the incandescent. It is also the least energy efficient. The filament in the bulb is so thin that it causes resistance in the electricity, which in turn causes the electricity's energy to form heat. This causes the incandescent to waste a lot of energy forming heat rather than forming the light. It uses 15 lumens per watt of input power. A recorded MATLAB demonstration showcased LED versatility and how it can be used by an Arduino UNO board. The objective of this thesis is to showcase how LEDs can reduce energy consumption through the use of an Arduino UNO board and MATLAB and to discuss the applications of LED. LED will be the future of lighting homes and will eventually completely incandescent bulbs when companies begin to make the necessary improvements to the LED.

  16. Straightforward fabrication of stable white LEDs by embedding of inorganic UV-LEDs into bulk polymerized polymethyl-methacrylate doped with organic dyes.

    Science.gov (United States)

    Di Martino, Daniela; Beverina, Luca; Sassi, Mauro; Brovelli, Sergio; Tubino, Riccardo; Meinardi, Francesco

    2014-01-01

    Stable white-emitting down-converted LEDs are straightforwardly prepared by bulk polymerization of an organic dye doped polymethyl-methacrylate (PMMA) shell directly on top of a highly efficient commercial blue-emitting InGaN LED. Our optimized polymerization procedure allows for extending the form factor of achievable luminescence converter (LUCO) material beyond the conventional thin film form and to directly produce devices with light bulb design. The selected organic dyes, the blue-emitting Coumarin 30 and a red-emitting diketopyrrolopyrrole derivative, exhibit high compatibility with the free radical polymerization reaction of the PMMA matrix and ensure high stability of the final hybrid device. The control of both the thickness of the PMMA shell and the concentration of the dopant dyes allow for fine tuning of the emission color of the LUCO LED and to obtain white light with CIE chromatic coordinates x = 0.32 and y = 0.33, with rendering index as high as 80. This simple and versatile procedure is not dye-exclusive and is therefore extendable to other molecular systems for color-tunable efficient solid-state lighting sources. PMID:24638041

  17. Straightforward fabrication of stable white LEDs by embedding of inorganic UV-LEDs into bulk polymerized polymethyl-methacrylate doped with organic dyes

    Science.gov (United States)

    di Martino, Daniela; Beverina, Luca; Sassi, Mauro; Brovelli, Sergio; Tubino, Riccardo; Meinardi, Francesco

    2014-03-01

    Stable white-emitting down-converted LEDs are straightforwardly prepared by bulk polymerization of an organic dye doped polymethyl-methacrylate (PMMA) shell directly on top of a highly efficient commercial blue-emitting InGaN LED. Our optimized polymerization procedure allows for extending the form factor of achievable luminescence converter (LUCO) material beyond the conventional thin film form and to directly produce devices with light bulb design. The selected organic dyes, the blue-emitting Coumarin 30 and a red-emitting diketopyrrolopyrrole derivative, exhibit high compatibility with the free radical polymerization reaction of the PMMA matrix and ensure high stability of the final hybrid device. The control of both the thickness of the PMMA shell and the concentration of the dopant dyes allow for fine tuning of the emission color of the LUCO LED and to obtain white light with CIE chromatic coordinates x = 0.32 and y = 0.33, with rendering index as high as 80. This simple and versatile procedure is not dye-exclusive and is therefore extendable to other molecular systems for color-tunable efficient solid-state lighting sources.

  18. Polymer dispensing and embossing technology for the lens type LED packaging

    International Nuclear Information System (INIS)

    This study presents a ring-type micro-structure design on the substrate and its corresponding micro fabrication processes for a lens-type light-emitting diode (LED) package. The dome-type or crater-type silicone lenses are achieved by a dispensing and embossing process rather than a molding process. Silicone with a high viscosity and thixotropy index is used as the encapsulant material. The ring-type micro structure is adopted to confine the dispensed silicone encapsulant so as to form the packaged lens. With the architecture and process described, this LED package technology herein has three merits: (1) the flexibility of lens-type LED package designs is enhanced; (2) a dome-type package design is used to enhance the intensity; (3) a crater-type package design is used to enhance the view angle. Measurement results show the ratio between the lens height and lens radius can vary from 0.4 to 1 by changing the volume of dispensed silicone. The view angles of dome-type and crater-type packages can reach 155° ± 5° and 175° ± 5°, respectively. As compared with the commercial plastic leaded chip carrier-type package, the luminous flux of a monochromatic blue light LED is improved by 15% by the dome-type package (improved by 7% by the crater-type package) and the luminous flux of a white light LED is improved by 25% by the dome-type package (improved by 13% by the crater-type package). The luminous flux of monochromatic blue light LED and white light LED are respectively improved by 8% and 12% by the dome-type package as compare with the crater-type package. (paper)

  19. Design of an Oximeter Based on LED-LED Configuration and FPGA Technology

    OpenAIRE

    Radovan Stojanovic; Dejan Karadaglic

    2013-01-01

    A fully digital photoplethysmographic (PPG) sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED) for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA) is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (SpO2). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (SpO2). N-LEDs...

  20. Determining contrast sensitivity functions for monochromatic light emitted by high-brightness LEDs

    Science.gov (United States)

    Ramamurthy, Vasudha; Narendran, Nadarajah; Freyssinier, Jean Paul; Raghavan, Ramesh; Boyce, Peter

    2004-01-01

    Light-emitting diode (LED) technology is becoming the choice for many lighting applications that require monochromatic light. However, one potential problem with LED-based lighting systems is uneven luminance patterns. Having a uniform luminance distribution is more important in some applications. One example where LEDs are becoming a viable alternative and luminance uniformity is an important criterion is backlighted monochromatic signage. The question is how much uniformity is required for these applications. Presently, there is no accepted metric that quantifies luminance uniformity. A recent publication proposed a method based on digital image analysis to quantify beam quality of reflectorized halogen lamps. To be able to employ such a technique to analyze colored beams generated by LED systems, it is necessary to have contrast sensitivity functions (CSFs) for monochromatic light produced by LEDs. Several factors including the luminance, visual field size, and spectral power distribution of the light affect the CSFs. Although CSFs exist for a variety of light sources at visual fields ranging from 2 degrees to 20 degrees, CSFs do not exist for red, green, and blue light produced by high-brightness LEDs at 2-degree and 10-degree visual fields and at luminances typical for backlighted signage. Therefore, the goal of the study was to develop a family of CSFs for 2-degree and 10-degree visual fields illuminated by narrow-band LEDs at typical luminances seen in backlighted signs. The details of the experiment and the results are presented in this manuscript.

  1. The use of light-emitting diodes (LED in commercial layer production

    Directory of Open Access Journals (Sweden)

    R Borille

    2013-06-01

    Full Text Available Artificial lighting is one of the most powerful management tools available to commercial layer producers. Artificial light allows anticipating or delaying the beginning of lay, improving egg production, and optimizing feed efficiency. This study aimed at comparing the performance of commercial layers submitted to lighting using different LED colors or conventional incandescent lamps. The study was carried out in a layer house divided in isolated environments in order to prevent any influenced from the neighboring treatments. In total, 360 Isa Brown layers, with an initial age of 56 weeks, were used. The following light sources were used: blue LED, yellow LED, green LED, red LED, white LED, and 40W incandescent light. Birds in all treatment were submitted to a 17-h continuous lighting program, and were fed a corn and soybean meal-based diet. A completely randomized experimental design with subplots was applied, with 24 treatments (six light sources and four periods of three replicates. Egg production (% was significantly different (p0.05 by light source. It was concluded that the replacement of incandescent light bulbs by white and red LEDs does not cause any negative effect on the egg production of commercial layers.

  2. White Light–Emitting Diodes (LEDs) at Domestic Lighting Levels and Retinal Injury in a Rat Model

    OpenAIRE

    Shang, Yu-Man; Wang, Gen-Shuh; Sliney, David; Yang, Chang-Hao; Lee, Li-Ling

    2013-01-01

    Background: Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina than do conventional domestic light sources. Chronic exposure to high-intensity light (2,000–10,000 lux) has previously been found to result in light-induced retinal injury, but chronic exposure to relatively low-intensity (750 lux) light has not been previously assessed with LEDs in a rodent model. Objective: We examined LED-induced retinal neuronal cell damage in the Sprague-Dawley rat using functiona...

  3. Preliminary Investigation of LED Lighting as Growth Light for Seedlings from Different Tree Species in Growth Chambers

    OpenAIRE

    Astolfi, Stefania; Chiara MARIANELLO; Stefano GREGO; Bellarosa, Rosanna

    2012-01-01

    The influence of light quality on growth and metabolic activity during pre-cultivation (in miniplug containers) of beech (Fagus sylvatica L.), holm oak (Quercus ilex L.) and wild cherry (Prunus avium) plants was investigated. Seedlings were grown in a growth chamber for a month under light-emitting diode (LED) light or fluorescent light. The LED lamps (Valoya) used in this study emitted a continuous spectrum thanks to a mixture of blue, green, red and far-red LEDs. Our results showed that pla...

  4. Thermoluminescence (TL) of Egyptian Blue

    Energy Technology Data Exchange (ETDEWEB)

    Schvoerer, M.; Delavergne, M.-C.; Chapoulie, R.

    1988-01-01

    Egyptian Blue is a synthesized crystalline pictorial pigment with formula CaCuSi/sub 4/O/sub 10/. It has been used in Egypt and Mesopotamia from the 3rd millenium B.C. A preliminary experiment on a recently synthesized sample showed that this pigment is thermoluminescent after ..beta.. irradiation (/sup 90/Sr). As the signal intensity grows linearly with the administered dose within the temperature range commonly used in TL dating, we have been looking for this phenomenon from archaeological pigments. It was encountered with two samples found in excavation. From its intensity and stability we concluded that Egyptian Blue can be dated using TL. This first and positive result encouraged us to extend the method to other types of mineral pigments synthesized by early man, and to suggest that it may be used for direct dating of ancient murals.

  5. Status of Blue Ridge Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Blue Ridge Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports and data available, as well as interview with water resource professionals in various federal, state, and local agencies. Blue Ridge Reservoir is a single-purpose hydropower generating project. When consistent with this primary objective, the reservoir is also operated to benefit secondary objectives including water quality, recreation, fish and aquatic habitat, development of shoreline, aesthetic quality, and other public and private uses that support overall regional economic growth and development. 8 refs., 1 fig.

  6. Food habits of blue grouse

    Science.gov (United States)

    Stewart, R.E.

    1944-01-01

    The food habits of Blue Grouse vary from a simple winter diet that is made up predominantly of coniferous needles to a complex diet during the summer months, characterized by great variety of foods including green leaves, fruits and seeds, flowers, animal matter and coniferous needles. The spring and fall, which represent the transition periods between these two, are characterized by feeding habits that are generally intermediate. The diets of the two species of Blue Grouse, Dendrugapus obscurus and Dendragapus juliginosus, are quite similar as far as major types of food are concerned, but they differ considerably in the species that are taken. Such differences reflect differences in the vegetation within the ecologic and geographic ranges occupied by the two species.

  7. Metal Complex Pigment Involved in the Blue Sepal Color Development of Hydrangea.

    Science.gov (United States)

    Oyama, Kin-ichi; Yamada, Tomomi; Ito, Daisuke; Kondo, Tadao; Yoshida, Kumi

    2015-09-01

    Anthocyanins exhibit various vivid colors from red through purple to blue and are potential sources of food colorants. However, their usage is restricted because of their instability, especially as a blue colorant. The blue sepal color of Hydrangea macrophylla is due to a metal complex named "hydrangea-blue complex" composed of delphinidin 3-O-glucoside, 1, 5-O-caffeoylquinic acid, 2, and/or 5-O-p-coumaroylquinic acid, 3, as copigments, and Al(3+) in aqueous solution at approximately pH 4.0. However, the ratio of each component ins not stoichiometric, but is fluctuates within a certain range. The hydrangea-blue complex exists only in aqueous solution, exhibiting a stable blue color, but attempts at crystallization have failed; therefore, the structure remains obscure. To clarify the basis of the character of the hydrangea-blue pigment and to obtain its structural information, we studied the mixing conditions to reconstruct the same blue color as observed in the sepals. In highly concentrated sodium acetate buffer (6 M, pH 4.0) we could measure (1)H NMR of both the hydrangea-blue complex composed of 1 (5 mM), 2 (10 mM), and Al(3+) (10 mM) and a simple 1-Al(3+) complex. We also recorded the spectra of complexes composed with structurally different anthocyanins and copigments. Comparison of those signals indicated that in the hydrangea-blue complex 1 might be under equilibrium between chelating and nonchelating structures having an interaction with 2. PMID:26006163

  8. Models of Individual Blue Stragglers

    CERN Document Server

    Sills, Alison

    2014-01-01

    This chapter describes the current state of models of individual blue stragglers. Stellar collisions, binary mergers (or coalescence), and partial or ongoing mass transfer have all been studied in some detail. The products of stellar collisions retain memory of their parent stars and are not fully mixed. Very high initial rotation rates must be reduced by an unknown process to allow the stars to collapse to the main sequence. The more massive collision products have shorter lifetimes than normal stars of the same mass, while products between low mass stars are long-lived and look very much like normal stars of their mass. Mass transfer can result in a merger, or can produce another binary system with a blue straggler and the remnant of the original primary. The products of binary mass transfer cover a larger portion of the colour-magnitude diagram than collision products for two reasons: there are more possible configurations which produce blue stragglers, and there are differing contributions to the blended ...

  9. Models of Individual Blue Stragglers

    Science.gov (United States)

    Sills, Alison

    This chapter describes the current state of models of individual blue stragglers. Stellar collisions, binary mergers (or coalescence), and partial or ongoing mass transfer have all been studied in some detail. The products of stellar collisions retain memory of their parent stars and are not fully mixed. Very high initial rotation rates must be reduced by an unknown process to allow the stars to collapse to the main sequence. The more massive collision products have shorter lifetimes than normal stars of the same mass, while products between low mass stars are long-lived and look very much like normal stars of their mass. Mass transfer can result in a merger, or can produce another binary system with a blue straggler and the remnant of the original primary. The products of binary mass transfer cover a larger portion of the colour-magnitude diagram than collision products for two reasons: there are more possible configurations which produce blue stragglers, and there are differing contributions to the blended light of the system. The effects of rotation may be substantial in both collision and merger products, and could result in significant mixing unless angular momentum is lost shortly after the formation event. Surface abundances may provide ways to distinguish between the formation mechanisms, but care must be taken to model the various mixing mechanisms properly before drawing strong conclusions. Avenues for future work are outlined.

  10. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karlicek, Robert, F., Jr; Sargent, Robert

    2012-05-14

    UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

  11. [Analysis on the degradation of optical properties of high power white LED].

    Science.gov (United States)

    Zhou, Zhou; Feng, Shi-Wei; Guo, Chun-Sheng; Zhang, Guang-Chen; Wu, Yan-Yan

    2012-10-01

    One watt white light emitting diodes (LEDs) were made by GaN-based blue light chips. The chips were coated by YAG phosphor and transparent silica gel. Current of 900 mA as electrical stress was carried on the LED samples and the optical properties of the samples were observed by measuring the main optical parameters during the aging test. After 4 200 hours of aging, the luminous flux rate of LEDs declined by a factor between 15% and 18%. Changes in I-V curves indicated the increase in leakage current, which were caused by the increase in defect density. Radiant flux of the blue light drawn from the spectrogram didn't decrease while the yellow light decreased obviously, which implies the degradation of conversion efficiency of YAG phosphor. Reasons for the increase in color temperature and keeping constant in color rendering index (CRI) were theoretically analyzed. The results of the experiment will provide a reference to the illumination applications of the high power white LED. PMID:23285849

  12. Review: Silicon-based oxynitride and nitride phosphors for white LEDs

    Directory of Open Access Journals (Sweden)

    Rong-Jun Xie and Naoto Hirosaki

    2007-01-01

    Full Text Available As a novel class of inorganic phosphors, oxynitride and nitride luminescent materials have received considerable attention because of their potential applications in solid-state lightings and displays. In this review we focus on recent developments in the preparation, crystal structure, luminescence and applications of silicon-based oxynitride and nitride phosphors for white light-emitting diodes (LEDs. The structures of silicon-based oxynitrides and nitrides (i.e., nitridosilicates, nitridoaluminosilicates, oxonitridosilicates, oxonitridoaluminosilicates, and sialons are generally built up of networks of crosslinking SiN4 tetrahedra. This is anticipated to significantly lower the excited state of the 5d electrons of doped rare-earth elements due to large crystal-field splitting and a strong nephelauxetic effect. This enables the silicon-based oxynitride and nitride phosphors to have a broad excitation band extending from the ultraviolet to visible-light range, and thus strongly absorb blue-to-green light. The structural versatility of oxynitride and nitride phosphors makes it possible to attain all the emission colors of blue, green, yellow, and red; thus, they are suitable for use in white LEDs. This novel class of phosphors has demonstrated its superior suitability for use in white LEDs and can be used in bichromatic or multichromatic LEDs with excellent properties of high luminous efficacy, high chromatic stability, a wide range of white light with adjustable correlated color temperatures (CCTs, and brilliant color-rendering properties.

  13. A new method to manipulate broiler chicken growth and metabolism: Response to mixed LED light system.

    Science.gov (United States)

    Yang, Yefeng; Yu, Yonghua; Pan, Jinming; Ying, Yibin; Zhou, Hong

    2016-01-01

    Present study introduced a new method to manipulate broiler chicken growth and metabolism by mixing the growth-advantage LED. We found that the green/blue LED mixed light system (G-B and G × B) have the similar stimulatory effect on chick body weight with single green light and single blue light (G and B), compared with normal artificial light (P = 0.028). Moreover, the percentage of carcass was significantly greater in the mixed light (G × B) when compared with the single light (P = 0.003). Synchronized with body weight, the mixed light (G-B and G × B) had a significant improved influence on the feed conversion of birds compared with normal light (P = 0.002). A significant improvement in feed conversion were found in mixed light (G × B) compared with single LED light (P = 0.037). G group resulted in a greater high-density lipoprotein cholesterol level than B group (P = 0.002), whereas B group resulted in a greater low-density lipoprotein cholesterol level than G group (P = 0.017). The mixed light significantly increased the birds' glucose level in comparison with the single light (P = 0.003). This study might establish an effective strategy for maximizing growth of chickens by mixed LED technology. PMID:27170597

  14. A new method to manipulate broiler chicken growth and metabolism: Response to mixed LED light system

    Science.gov (United States)

    Yang, Yefeng; Yu, Yonghua; Pan, Jinming; Ying, Yibin; Zhou, Hong

    2016-05-01

    Present study introduced a new method to manipulate broiler chicken growth and metabolism by mixing the growth-advantage LED. We found that the green/blue LED mixed light system (G-B and G × B) have the similar stimulatory effect on chick body weight with single green light and single blue light (G and B), compared with normal artificial light (P = 0.028). Moreover, the percentage of carcass was significantly greater in the mixed light (G × B) when compared with the single light (P = 0.003). Synchronized with body weight, the mixed light (G-B and G × B) had a significant improved influence on the feed conversion of birds compared with normal light (P = 0.002). A significant improvement in feed conversion were found in mixed light (G × B) compared with single LED light (P = 0.037). G group resulted in a greater high-density lipoprotein cholesterol level than B group (P = 0.002), whereas B group resulted in a greater low-density lipoprotein cholesterol level than G group (P = 0.017). The mixed light significantly increased the birds’ glucose level in comparison with the single light (P = 0.003). This study might establish an effective strategy for maximizing growth of chickens by mixed LED technology.

  15. Study on the stability of the high-brightness white LED

    Science.gov (United States)

    Chen, Z. Z.; Zhao, J.; Qin, Z. X.; Hu, X. D.; Yu, T. J.; Tong, Y. Z.; Yang, Z. J.; Zhou, X. Y.; Yao, G. Q.; Zhang, B.; Zhang, G. Y.

    2004-10-01

    The high-power white light emitting diode (LED) is packaged by GaN-based blue LED chip with the size of 1 × 1 mm2, YAG:Ce yellow fluorescer, epoxy and an effective heat sinking. The wavelength of the LED chip emission blue-shifts from 482 to 475 nm, while that of the fluorescer emission does not change in electroluminescence (EL) spectrum when the injection current increases from 5 to 200 mA. And the correlated color temperature decreases from 5300 to 4800 K. When the injection current increases to 200 mA, the luminous power (Pe) increases to 13.8 mW, which is about 10 times of those of the normal size (0.3 × 0.3 mm2) diodes fabricated with the same wafer and same injection density. Pe and forward bias (Vf) at 200 mA are measured for the aging high-power white LED. At the beginning, Pe decreases dramatically 20% and Vf decreases about 0.2 V in 2 days. And then Pe and Vf decrease slowly in the remaining 79 days aging. The contact metals electro migration along the channels induced by the threading dislocations may be the dominant aging mechanism.

  16. An LED pulser for measuring photomultiplier linearity

    OpenAIRE

    Friend, M.; Franklin, G. B.; B. Quinn

    2011-01-01

    A light-emitting diode (LED) pulser for testing the low-rate response of a photomultiplier tube (PMT) to scintillator-like pulses has been designed, developed, and implemented. This pulser is intended to simulate 80 ns full width at half maximum photon pulses over the dynamic range of the PMT, in order to precisely determine PMT linearity. This particular design has the advantage that, unlike many LED test rigs, it does not require the use of multiple calibrated LEDs, making it insensitive to...

  17. Inflation and alternatives with blue tensor spectra

    International Nuclear Information System (INIS)

    We study the tilt of the primordial gravitational waves spectrum. A hint of blue tilt is shown from analyzing the BICEP2 and POLARBEAR data. Motivated by this, we explore the possibilities of blue tensor spectra from the very early universe cosmology models, including null energy condition violating inflation, inflation with general initial conditions, and string gas cosmology, etc. For the simplest G-inflation, blue tensor spectrum also implies blue scalar spectrum. In general, the inflation models with blue tensor spectra indicate large non-Gaussianities. On the other hand, string gas cosmology predicts blue tensor spectrum with highly Gaussian fluctuations. If further experiments do confirm the blue tensor spectrum, non-Gaussianity becomes a distinguishing test between inflation and alternatives

  18. Localized Eruptive Blue Nevi after Herpes Zoster

    Science.gov (United States)

    Colson, Fany; Arrese, Jorge E.; Nikkels, Arjen F.

    2016-01-01

    A 52-year-old White man presented with a dozen small, well-restricted, punctiform, asymptomatic, blue-gray macules on the left shoulder. A few months earlier, he had been treated with oral acyclovir for herpes zoster (HZ) affecting the left C7–C8 dermatomes. All the blue macules appeared over a short period of time and then remained stable. The patient had not experienced any previous trauma or had tattooing in this anatomical region. The clinical diagnosis suggested blue nevi. Dermatoscopy revealed small, well-limited, dark-blue, compact, homogeneous areas evoking dermal blue nevi. An excisional biopsy was performed and the histological examination confirmed a blue nevus. As far as we are aware of, this is the first report of eruptive blue nevi following HZ, and it should be included in the differential diagnosis of zosteriform dermatoses responding to an isotopic pathway. In addition, a brief review concerning eruptive nevi is presented. PMID:27462219

  19. LED Based Spectrophotometer can compete with conventional one

    Directory of Open Access Journals (Sweden)

    Karim Aly Mohammad

    2015-05-01

    Full Text Available Spectrophotometers are the common devise used for blood analysis. These analyses are simply optioned from the transmittance of monochromatic light through a blood sample. It disperses their light sources by different techniques; the simplest one is the use of interference filters in front of broad-band light source. As Interference bandpass filters are relatively inexpensive wavelength selectors. Interference filters that allow transmission of a predetermined wavelength while rejecting or blocking other wavelengths are widely used in instrumentation for clinical chemistry. On the other hand, the lights emitting diodes (LEDs emits a specified band and have a wide selection options.  An economic device based on LEDs (LED based spectrometer is explained in this work. Instead of the wide spectrum light source and filters (commercial spectrophotometer, The LED based spectrophotometer is calibrated with standard solutions, and its measurement results is compared with the Mindray BS-200 Chemistry Analyzer (commercial spectrophotometer. The comparison shows acceptable results between both spectrophotometers with maximum error 2.33%. The errors can be reduced by applying more fining alignment. Another benefit of the new designee is to minimize testing costs.

  20. 27 CFR 21.119 - Nicotine solution.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Nicotine solution. 21.119....119 Nicotine solution. (a) Composition. Five gallons of an aqueous solution containing 40 percent nicotine; 3.6 avoirdupois ounces of methylene blue, U.S.P.; water sufficient to make 100 gallons. (b)...