White Fluorescent Lamps Research Articles

Crop Diversification In Ontario: Adaptation of Annual Globe Artichokes

Globe artichoke (Cynara scolymus L.) is a high value cool season crop which requires vernalization to induce flower formation. The climate in Ontario does not allow for survival of perennial cultivars or for consistent natural vernalization of annuals. Three methods of vernalization were tested: a controlled environment chamber, a lighted cold storage, or GA3 application in the field. Plants, cv. Green Globe Improved, were grown in a greenhouse set at 25 °C day temperature in 72-cell Styro-foam trays in a peat mix. At 4 weeks, plants receiving vernalization were transferred to growth chambers, or lighted coolers (four standard 8 foot cool white fluorescent lamps) at 10 °C for two weeks. The others stayed in the greenhouse. GA3 treatments (PROGIB, 15 g ai/ha) were applied at 2, 4 and 6 weeks after transplanting. Cultivars Green Globe Improved, Imperial Star, Emerald, and Large Green Globe were evaluated in separate trials. Trials were conducted at Simcoe, on coarse sand in a high heat area, and Kettleby, on organic soils in a cooler area of Ontario. Shortly after planting at Simcoe several 30 °C days occurred which devernalized and injured the crop. Artichokes grew well at the Kettleby site. Vernalization in the growth chamber was most effective and resulted in the earliest bud formation and highest total yield (1503 cases/ha). Large Green Globe was not well adapted to Ontario conditions. Imperial Star and Emerald produced the highest yields, 2180 and 1779 cases/ha, respectively. Globe artichokes can be grown successfully as an annual crop in cool production areas of Ontario.

Photodecomposition and Bioconcentration of a Bisphenol A Metabolite in Medaka, Oryzias latipes

Exposure experiments in medaka and photodecomposition tests were performed using a metabolite of bisphenol A [4-methyl-2,4-bis(p-hydroxyphenyl)-pent-1-ene; MBP], the solubility limit of which is 42 mg/l of water. Three adult medaka were kept in a 2 l glass beaker at 25 ± 1°C for 4 days. The LC50 for 96 hr was > 1000 ppb. The measured average MBP concentration in the breeding water (nominal concentration of 100 ppb) was 49.2 ppb. The average concentration in the whole bodies of medaka after 4 days was 1.92 mg/g-wet body, and the bioconcentration factor (BCF) of MBP was calculated to be 39.0. MBP in water and acetone was decomposed very easily, with about 98% of the MBP being decomposed after several hours under sunlight. MBP was also decomposed after 48 hr of illumination under a white fluorescent lamp.

Ácido giberélico (ga3) e 6-benzilaminopurina (bap) no crescimento in vitro de macela [Egletes viscosa (L.) Less.

A micropropagação é uma ferramenta promissora que pode ser utilizada para propagação e preservação de muitas espécies de plantas medicinais que vêm sendo exploradas de forma indiscriminada e que estão em vias de extinção. Conduziu-se este trabalho com o objetivo de induzir o crescimento in vitro de brotações de macela, em meio de cultura MS com diferentes concentrações de GA3 (0; 0,1 e 0,5 mgL-1) e BAP (0; 1 e 2 mgL-1). Foram utilizadas brotações de macela com diâmetro médio de 1,5 cm, retiradas de plantas preestabelecidas in vitro, inoculadas em frascos contendo 40 ml do meio de cultura e mantidas em sala de crescimento com temperatura média de 26 ± 1oC, fotoperíodo de 16 h e intensidade luminosa em torno de 2000 lux fornecida por lâmpada tipo fluorescente branca fria. Utilizou-se como delineamento experimental um fatorial 3 x 3, num total de nove tratamentos com 15 explantes por tratamento. Aos 30 dias, verificou-se o maior crescimento em altura das plantas, no tratamento com 0,5 mgL-1 de GA3 na ausência de BAP. O maior número de brotações ou crescimento em diâmetro foi observado com maiores concentrações dos reguladores. Porém, na presença dos reguladores ocorreu um maior número de plantas com folhas hiperhídricas e malformadas.

Estabelecimento e multiplicação in vitro de Prunus sp. em diferentes meios de cultivo

O trabalho foi realizado com o objetivo de avaliar diferentes meios de cultivo no estabelecimento e multiplicação in vitro de espécies do gênero Prunus. Os segmentos nodais de 1,0 cm foram mantidos sob luz fluorescente com radiação de 20 mE.m-2.s-1, fotoperíodo de 16 horas e temperatura de 25±2ºC. No estabelecimento, testaram os meios MS, MS ¾, SH e Villegas, e na multiplicação: SH e MS ¾. O meio MS ¾ foi testado em diferentes concentrações de ágar (4,5; 5,5; 6,5 g.L-1). Avaliaram-se as percentagens de estabelecimento dos explantes, contaminação, oxidação e segmentos não brotados. O meio Villegas apresentou menor oxidação durante o período de estabelecimento in vitro. Com o meio MS ¾, verificou-se maior percentagem de estabelecimento dos explantes. Na fase de multiplicação, avaliaram-se a percentagem de crescimento, a taxa de multiplicação e o número de brotações. O meio MS ¾, com 5,5 g.L-1 de ágar, apresentou os melhores resultados.

赤・青色ＬＥＤ弱光照射低温貯蔵における青色光ＰＰＦＤ比率がトマト接ぎ木セル成型苗の品質に及ぼす影響

Grafted tomato (scion : Lycopersicon esculentum Mill. cv. House Momotaro ; rootstock : cv. Kagemusha) plug seedlings were stored for 35 d at 10°C under total photosynthetic photon flux density (PPFD) of 2μmol m-2s-1 using mixed light from red and blue light emitting diodes (LEDs), with different percentages of blue-light PPFD (0%: R100, 2%: R98B2, 5%: R95B5, 10%: R90B10, and 50%: R50B50) . The stored seedlings were transplanted and then cultivated for 28 d at 27°C and 290μmol m-2s-1 PPFD from white fluorescent lamps during the 12h light period and at 18°C during the 12h dark period. The effect of blue-light PPFD percentage was investigated and the best percentage was synthetically determined based on 5 and 8 items for the last days of storage and cultivation, respectively. An improving tendency was observed by increasing the percentage of blue-light PPFD in visual quality scores and leaf area on the last day of storage, aerial- and subterranean- part dry weights on the last day of cultivation. There was no applicable tendency in other items with increasing the percentage. It can be concluded that the 50% of blue-light PPFD was the best percentage among the tested ones and increasing the percentage up to 50% contributed to quality improvements for low light irradiation storage of grafted tomato plug seedlings at 10°C and 2μmol m-2s-1 PPFD from red and blue LEDs.

Lightfastness Studies of Water-based Inkjet Inks on Coated and Uncoated Papers

Instrumental color (i.e. L*A*B*) and optical density measurements were performed on coated and uncoated papers printed with water based inkjet inks using continuous binary array inkjet equipment. Lightfastness tests were performed in a QUV test chamber with Cool White Fluorescent lamps, Q-Sun Xenon Arc Test Chamber with a Window Glass Filter, and under glass at a Florida outdoor benchmark location (Q-Lab Weathering Research Service). These results were compared with two indoor exposure locations. Rank order was used to show good correlation between the various exposure methods. The results of this study generated data indicating that the lightfastness of water-based inkjet inks can be complex and dictated by the type of coated or uncoated paper used. This study also shows that inks printed on coated substrates are more susceptible to UV degradation than those printed on a bond or uncoated substrate. The development of a light stability test protocol is intended to simulate the conditions of the actual service environment. Meaningful data can be produced to better evaluate the “archivability” or predict durability of inkjet inks and substrates.

Effects of Long-day Treatment at Different Light Intensities on Maturation and Fruit Quality in Japanese Persimmon 'Saijo'

To delay harvest of Japanese persimmon 'Saijo' (Diospyros kaki Thumb.) grown under a greenhouse, the effects of a long-day photoperiod at different light intensities on tree growth and fruit quality were tested. Exposure of 'Saijo' trees to intensive light from August 27 to December 8 under 17±1 hr photoperiod with white fluorescent lamps increased leaf color (SPAD value), secondary shoot growth, and the flesh firmness of the fruit while delaying leaf abscission, fruit color development and decreasing soluble solids content (Brix). These results indicate that the long-day treatment somehow caused delay in fruit maturation and enhances vegetative growth in 'Saijo'. The optimum value of photon flux density (PFD) on the canopy surface was estimated to be 1.5 μmol·m-2·sec-1 to delay harvest of 'Saijo' by approximately 25 days.

Characteristics of Marine Microalgae as a Result of the Change in Light Quality During the Culture Period

The recent scarcity of several marine stocks in Japan is a serious problem. Aquaculture has been increasing, but requires large amounts of marine microalgae as a food source. Therefore, this study was aimed at developing a system to mass-produce the microalgae Pavlova, using artificial light sources. Pavlova cells were grown under white, red, green, and blue fluorescent lamps. The highest cell density was obtained after 8-9 days of culture under white fluorescent lamps. The highest rate of oxygen generation by Pavlova cells was found at photosynthetic photon flux densities (PPFD) of 300 to 500 µmol m-2 s-1 in cultures grown under the white fluorescent lamps. Pavlova cells cultured under other cotored fluorescent lamps generated maximal oxygen rates at PPFD around 150 µmol m-2 s-1.

Transformations of the wavelength of the light incident upon CdS/CdTe solar cells

A method for the improvement of the spectral response of the CdS/CdTe solar cell was proposed. The coatings of fluorescent coloring agent (FCA) on the cell made the cell sensitive to light at wavelengths below 510 nm, transforming the wavelength of the incident light from non-incentive region (below 510 nm) to incentive region (above 510 nm). The FCA coatings showed about 8% and 14% increases in the maximum power of the solar cell under the radiations of a white and day-light fluorescent lamp, respectively. Possible maximum output powers were predicted by using a simple model for the external quantum efficiency of the cell.

Characteristics of Marine Microalgae as a result of the Change in Light Quality during the Culture Period

Abstract The recent scarcity of several marine stocks in Japan is a serious problem. Aquaculture has been increasing, but requires large amounts of marine microalgae as a food source. Therefore, this study was aimed at developing a system to mass-produce the microalgae Pavlova , using artificial light sources. Pavlova cells were grown under white, red, green, and blue fluorescent lamps. The highest cell density was obtained after 8-9 days of culture under white fluorescent lamps. The highest rate of oxygen generation by Pavlova cells was found at photosynthetic photon flux densities (PPFD) of 300 to 500 µmol m -2 s -1 in cultures grown under the white fluorescent lamps. Pavlova cells cultured under other cotored fluorescent lamps generated maximal oxygen rates at PPFD around 150 µmol m -2 s -1 .

Adenine, adenosine monophosphate, and cytokinin: nutrients for rice seedling growth in the summer crop season

Adenine, adenosine monophosphate (AMP), and cytokinin (isopentenyl adenine [IPA], transzeatin [t-Z], and dihydrozeatin [DHZ]) were tested to determine whether they could promote seedling growth of rice variety Tai-Keng 3 in Taiwan. Adenine and AMP are precursors of the biosynthesis of ATP, nucleic acids, coenzyme A, FAD NAD + , and cytokinin. Cytokinin is an inducer of protein synthesis and cell division. Rice seeds were surface-sterilized with 10% NaOCl for 10 min, rinsed with distilled water a few times, and placed under white fluorescent lamps (20 μmol m -2 s -1 ) for germination at 26°C. Distilled water was replaced daily. Five-day-old germinating seeds were transferred to culture solutions, which included Hoagland solution [Ca(NO 3 ) 2 , 5.0 × 10 -3 mol L -1 ; KNO 3 , 5.0 × 10 -3 mol L -1 ; MgSO 4 , 2.0 × 10 -3 mol L -1 ; KH 2 PO 4 1.0 × 10 -3 mol L -1 ; Fe EDTA, 1.18 × 10 -5 mol L -1 ; and micronutrient solution consisting of H3BO3, 4.6 × 10-5 mol L -1 ; MnCl 2 • 4 H 2 O, 9.14 × 10 -6 mol L -1 ; ZnSO 4 • 4 H2O, 7.65 × 10 -7 mol L -1 ; CuSO 4 , 7.0 × 10 -7 mol L -1 ; and H 2 MoO 4 , 1.24 × 10 -7 mol L -1 ; pH 5.0; and in which adenine, AMP, IPA, t-Z, and DHZ were each added to make concentrations from 10 -9 to 10 -16 M].

Photochemical and oxidative degradation of the solid-state tretinoin tocoferil.

The photostability of tretinoin tocoferil was investigated under irradiation with three kinds of lamps, i.e., a cool white fluorescent lamp, a UV-A fluorescent lamp and a D65 fluorescent lamp. A combination of the cool white fluorescent lamp and the UV-A fluorescent lamp, and the D65 lamp having relative spectral power distribution similar to that of direct daylight, correspond to options 2 and 1 in ICH Guidelines, respectively. The photodegradation apparently followed second-order kinetics under these light sources and the degradation rate constant under exposure by the D65 lamp was larger than that by the cool white fluorescent lamp. The drug was susceptible to degradation by visible and UV light below 480 nm and was degraded most remarkably at around 420 nm, showing a wavelength-dependency. The semi-logarithmic plots of apparent degradation rate constant against the reciprocal of illuminance showed a good linear relationship in the Arrhenius-type fashion, and the photostability under ordinary illumination conditions could be predicted from the data obtained under the accelerated illumination conditions. The rate of oxidative degradation was slightly accelerated with the rise of temperature. Thermodynamic parameter was calculated from the Arrhenius plot. The degradation rate constant rapidly increased in proportion to partial pressure of oxygen below 20 kPa.

Vibrio harveyi bioluminescence plays a role in stimulation of DNA repair.

Although the genetics and biochemistry of bacterial luminescence have been investigated extensively, the biological role of this phenomenon remains unclear. Here it is shown that luxA, luxB and luxD mutants (unable to emit light) of the marine bacterium Vibrio harveyi are significantly more sensitive to UV irradiation when cultivated in the dark after irradiation than when cultivated under a white fluorescent lamp. This difference was much less pronounced in the wild-type (luminescent) V. harveyi strain. Survival of UV-irradiated Escherichia coli wild-type cells depended on subsequent cultivation conditions (in the dark or in the presence of external light). However, after UV irradiation, the percentage of surviving E. coli cells that bear V. harveyi genes responsible for luminescence was significantly higher than that of non-luminescent E. coli, irrespective of the subsequent cultivation conditions. Moreover, it is demonstrated that luminescence of V. harveyi can be stimulated by UV irradiation even in diluted cultures, under conditions when light emission by these bacteria is normally impaired due to quorum sensing regulation. It is proposed that luminescent bacteria have an internal source of light which could be used in DNA repair by a photoreactivation process. Therefore, production of internal light ensuring effective DNA repair seems to be at least one of the biological functions of bacterial luminescence.

Anaerobic oxidation of dissolved hydrogen sulfide in continuous culture of the phototrophic bacterium Prosthecochloris aestuarii

The anaerobic oxidation of dissolved H 2S to elemental sulfur was studied at 23°C and pH 6.5±0.3 in continuous culture of the phototrophic green sulfur bacterium Prosthecochloris aestuarii. The number of cells formed in the cultures was proportional to the amount of H 2S oxidized, and the growth yield was independent of light intensity. The specific growth rate was significantly dependent on the dissolved H 2S concentration and light intensity. The kinetic data were analyzed with a rate expression as a function of each rate-limiting factor. Under illumination by white fluorescent lamps, the specific oxidation rate of P. aestuarii reached a maximum of 2.02 × 10 −14 mol-H 2S•h −1•cell −1 when the dissolved H 2S concentration was 2.1 mM at 5000 lx. Simultaneous use of near infrared LED (light-emitting diode) and white fluorescent lamps provided a 35% increase in the maximum specific H 2S oxidation rate.

Avoiding pitfalls in the determination of halocarboxylic acids: the photochemistry of methylation.

Haloethanoic (haloacetic) acids are formed during chlorination of drinking water and are regulated by the Environmental Protection Agency (EPA). These compounds are normally quantified by gas chromatography with electron capture detection (GC-ECD) as the methyl esters. EPA Method 552 uses diazomethane (CH2N2) for this purpose, but has only been validated by EPA for HAA6: chloro-, dichloro-, bromo-, dibromo-, bromochloro- and trichloroacetic acids. EPA Method 552.2 was developed and validated for all nine analytes (HAA9 = HAA6 + dibromochloro-, bromodichloro- and tribromoethanoic acids). Since the promulgation of Method 552.2, which uses acidic methanol, a debate has ensued over discrepancies observed by various laboratories when using diazomethane instead. In an effort to identify and eliminate potential sources for these discrepancies, a comparative study was undertaken for HAA9. Better accuracy and precision were observed for all HAA9 species by Method 552.2; recoveries were satisfactory in de-ionized and tap water. Method 552 remains satisfactory for HAA6. Systematic differences in instrumental response are observed for the two methods, but these are precise and may be accounted for using similarly treated standards and analyte-fortified (spiked) samples. That notwithstanding, Method 552 (CH2N2) was shown to be unsuitable for dibromochloro-, bromodichloro- and tribromoethanoic acids (HAA9-6). The primary problem appears to be a photoactivated reaction between diazomethane and the HAA9-6 analytes; however, side reactions were found to occur even in the dark. Analyte loss is most pronounced under typical laboratory lighting (white F40 fluorescent lamps + sunlight), but it is also observed under Philips gold F40 lamps (lambda > or = 520 nm), and in the dark.

110 Callogenesis and Organogenesis of the Apple Rootstock (Malus prunifolia) cv. Marubakaido under Different Aluminum Concentrations and Different Locations of Explants in the Leaf

Three different leaf segments (apical, basal, and middle) were treated in combination with aluminum at 0, 5, 10, 15 and 20 mg·L-1. Three kinds of leaf segments were inoculated in flasks in 12 replicates, with the adaxial surface touching the medium composed by basic macro- and micronutrient and MS vitamins added to 2,4-D (1.0 mg·L-1); BAP (5.0 mg·L-1); sucrose (30.0 g·L-1); myo-inositol (100.0 mg·L-1) and agar (6.0 g·L-1). The pH was adjusted to 4.0 before autoclaving. After inoculation, the explants were incubated in a dark growth room for 21 days and then, placed during 80 days, at 25 ± 2 °C, 16-h photoperiod provided by white fluorescent lamps under 19 μE·m-2·s-1 radiation. At the end of this period, the explants were evaluated. It was observed that basal leaf explants provided greener callus and that the heavier ones came from the middle leaf explants. Absence of Al or high Al concentrations favored the number of adventitious buds, whereas intermediate concentrations inhibited them. The absence of Al favored basal explants to form adventitious shoots, while lower concentrations favored apical and basal segments. High Al concentration appear to stimulate adventitious shoots in the basal and middle explants. Although it was evident that callus intensities were lower in higher Al concentration, Al is not so harmful to callogenesis and organogenesis.

Effect of irradiance on shoot development in vitro

The growth of Disanthus cercidifolius and Rhododendron cultivars, and to a lesser extent Crataegus oxyacantha cv. Paul's Scarlet, was modified by altering either the spectral quality or the level of irradiance received by shoot cultures; which were otherwise maintained under uniform medium and plant growth regulator (PGR) conditions in vitro. When the spectrum of Philips colour 84 (white) fluorescent lamps was modified by coloured cellulose acetate filters, red light promoted shoot extension and axillary branching, whereas blue light inhibited shoot growth and reduced leaf chlorophyll content in the sensitive cultivar R. cv. Dopey. By using single or multiple layers of neutral density filters, or moving cultures nearer to the light source, irradiance from white light was varied. All cultures grew well at low levels of irradiance (c. 11 µmol m−2 s−1), but the growth and leaf chlorophyll content of cultures of Disanthus and Rhododendron cultivars were suppressed by increasing irradiance. In three related Rhododendron cultivars, increased irradiance promoted the development of adventitious shoots. Crataegus shoots were tolerant of a wide range of irradiances and only shoot extension was inhibited at the highest level tested; leaf chlorophyll content was unaffected. These results are discussed in terms of the differential perception of light relative to the natural habitats of these plants, and of the possible direct effect of irradiance upon PGRs in the culture system.

12.1: LED Backlight for LCDs

AbstractCold cathode type fluorescent lamp is widely used for color AM‐LCD back light because of its high efficiency. Recently, high efficiency blue and green LED are become available in the market, which has better color purity than that of fluorescent lamp. In this paper, we studied their potential for the use of LCD back light.LED back light has an advantage of response time over conventional fluorescent lamps especially when considering color sequential display1 or moving image quality improvement2.Power efficiency, and spectra of Blue, Green, Red, and white fluorescent lamps and Blue, Green, Red LED's were measured, and driving current ratio of each color LED's, power efficiency, optical power output and brightness of the LED backlight were simulated assuming the white LED backlight has a same chromaticity as that of conventional fluorescent lamp.

Preparation and Photovoltaic Properties of a Sintered CdS/CdTe Thin Film Light Sensor

The sintered CdS/CdTe thin-film photovoltaic cells have been prepared on borosilicate glass substrates by successively repeating screen printing and sintering. The preparation conditions of the sintered CdS/CdTe cell for a visible-light-radiation sensor were investigated. The sintering condition of CdTe film has a strong influence on the electrical and the optical properties of the CdS/CdTe junction. The optimum sintering condition of CdTe on the as-sintered US film with less 0.1wt% of CdCl2 was 600-620°C for 60 minutes.The sintered CdS/CdTe photovoltaic cells show a spectral response of the quantum efficiency nearly constant in the range of 530 to 850nm. The temperature coefficient of short-circuit current density is almost constant in the range of -50 to 70°C. The temperature coefficient of open-circuit voltage is about -1.85mV/°C. The cell shows a linear dependence of short-circuit current density on light intensity over the whole measurement range. A photosensitivity under a white fluorescent lamp and a response time of the cell are about 0.7nA/mm2⋅lx and about 3μs respectively. These values of the CdS/CdTe cells are comparable to those of a typical single crystal silicon p-n photodiode. The sintered CdS/CdTe photovoltaic cell can be used as a visible-light-radiation sensor.

Far‐red light inhibits growth but promotes carotenoid accumulation in the green microalga Dunaliella bardawil

It has been demonstrated that far‐red light reduces growth of marine phytoplankton and that light quality controls growth and photosynthetic metabolism in algae. The green halotolerant microalga, Dunaliella bardawil, accumulates high amounts of β‐carotene (up to 10% of its dry weight) under conditions of high light or nutrient limitation. The influence of increasing irradiance and of far‐red light in D. bardawil was studied. Continuous irradiance was provided by white fluorescent lamps alone (WL) or supplemented with far‐red Linestra lamps (WL+FR). For both types of light, cultures were acclimatized at increasing irradiances (50‐300 µmol m−2 s−1), and cell density, photosynthetic activity and pigment content were determined. Cell density increased with the photon irradiance, and was higher in WL than in WL+FR under the same irradiance, but the reverse occurred in respect of cell volume. Growth rate was higher under WL+FR. Far‐red light induced faster growth but reduced the maximal cell density of the cultures. Chlorophyll a concentration was higher in white light, but total carotenoid content increased dramatically in both far‐red light treatments (about 50% on a per cell basis) and with the increase of irradiance. Our results show that far‐red light has a significant influence on growth and photosynthesis of D. bardawil, inducing a decrease in cell density, photosynthetic activity and chlorophyll concentration, and an increase in growth rate, cell volume and carotenoid content.