Transcriptome sequencing and de novo analysis of cytoplasmic male sterility and maintenance in JA-CMS cotton.

PubMed

Yang, Peng; Han, Jinfeng; Huang, Jinling

2014-01-01

Cytoplasmic male sterility (CMS) is the failure to produce functional pollen, which is inherited maternally. And it is known that anther development is modulated through complicated interactions between nuclear and mitochondrial genes in sporophytic and gametophytic tissues. However, an unbiased transcriptome sequencing analysis of CMS in cotton is currently lacking in the literature. This study compared differentially expressed (DE) genes of floral buds at the sporogenous cells stage (SS) and microsporocyte stage (MS) (the two most important stages for pollen abortion in JA-CMS) between JA-CMS and its fertile maintainer line JB cotton plants, using the Illumina HiSeq 2000 sequencing platform. A total of 709 (1.8%) DE genes including 293 up-regulated and 416 down-regulated genes were identified in JA-CMS line comparing with its maintainer line at the SS stage, and 644 (1.6%) DE genes with 263 up-regulated and 381 down-regulated genes were detected at the MS stage. By comparing the two stages in the same material, there were 8 up-regulated and 9 down-regulated DE genes in JA-CMS line and 29 up-regulated and 9 down-regulated DE genes in JB maintainer line at the MS stage. Quantitative RT-PCR was used to validate 7 randomly selected DE genes. Bioinformatics analysis revealed that genes involved in reduction-oxidation reactions and alpha-linolenic acid metabolism were down-regulated, while genes pertaining to photosynthesis and flavonoid biosynthesis were up-regulated in JA-CMS floral buds compared with their JB counterparts at the SS and/or MS stages. All these four biological processes play important roles in reactive oxygen species (ROS) homeostasis, which may be an important factor contributing to the sterile trait of JA-CMS. Further experiments are warranted to elucidate molecular mechanisms of these genes that lead to CMS.

Transcriptome Sequencing and De Novo Analysis of Cytoplasmic Male Sterility and Maintenance in JA-CMS Cotton

PubMed Central

Yang, Peng; Han, Jinfeng; Huang, Jinling

2014-01-01

Cytoplasmic male sterility (CMS) is the failure to produce functional pollen, which is inherited maternally. And it is known that anther development is modulated through complicated interactions between nuclear and mitochondrial genes in sporophytic and gametophytic tissues. However, an unbiased transcriptome sequencing analysis of CMS in cotton is currently lacking in the literature. This study compared differentially expressed (DE) genes of floral buds at the sporogenous cells stage (SS) and microsporocyte stage (MS) (the two most important stages for pollen abortion in JA-CMS) between JA-CMS and its fertile maintainer line JB cotton plants, using the Illumina HiSeq 2000 sequencing platform. A total of 709 (1.8%) DE genes including 293 up-regulated and 416 down-regulated genes were identified in JA-CMS line comparing with its maintainer line at the SS stage, and 644 (1.6%) DE genes with 263 up-regulated and 381 down-regulated genes were detected at the MS stage. By comparing the two stages in the same material, there were 8 up-regulated and 9 down-regulated DE genes in JA-CMS line and 29 up-regulated and 9 down-regulated DE genes in JB maintainer line at the MS stage. Quantitative RT-PCR was used to validate 7 randomly selected DE genes. Bioinformatics analysis revealed that genes involved in reduction-oxidation reactions and alpha-linolenic acid metabolism were down-regulated, while genes pertaining to photosynthesis and flavonoid biosynthesis were up-regulated in JA-CMS floral buds compared with their JB counterparts at the SS and/or MS stages. All these four biological processes play important roles in reactive oxygen species (ROS) homeostasis, which may be an important factor contributing to the sterile trait of JA-CMS. Further experiments are warranted to elucidate molecular mechanisms of these genes that lead to CMS. PMID:25372034

Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction.

PubMed

Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de Los Santos, Berta; Arroyo, Francisco T; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L

2016-01-01

Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen.

Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction

PubMed Central

Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de los Santos, Berta; Arroyo, Francisco T.; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L.

2016-01-01

Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen. PMID:27471515

MAPK-dependent JA and SA signalling in Nicotiana attenuata affects plant growth and fitness during competition with conspecifics

PubMed Central

2012-01-01

Background Induced defense responses to herbivores are generally believed to have evolved as cost-saving strategies that defer the fitness costs of defense metabolism until these defenses are needed. The fitness costs of jasmonate (JA)-mediated defenses have been well documented. Those of the early signaling units mediating induced resistance to herbivores have yet to be examined. Early signaling components that mediate herbivore-induced defense responses in Nicotiana attenuata, have been well characterized and here we examine their growth and fitness costs during competition with conspecifics. Two mitogen-activated protein kinases (MAPKs), salicylic acid (SA)-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK) are rapidly activated after perception of herbivory and both kinases regulate herbivory-induced JA levels and JA-mediated defense metabolite accumulations. Since JA-induced defenses result in resource-based trade-offs that compromise plant productivity, we evaluated if silencing SIPK (irSIPK) and WIPK (irWIPK) benefits the growth and fitness of plants competiting with wild type (WT) plants, as has been shown for plants silenced in JA-signaling by the reduction of Lipoxygenase 3 (LOX3) levels. Results As expected, irWIPK and LOX3-silenced plants out-performed their competing WT plants. Surprisingly, irSIPK plants, which have the largest reductions in JA signaling, did not. Phytohormone profiling of leaves revealed that irSIPK plants accumulated higher levels of SA compared to WT. To test the hypothesis that these high levels of SA, and their presumed associated fitness costs of pathogen associated defenses in irSIPK plants had nullified the JA-deficiency-mediated growth benefits in these plants, we genetically reduced SA levels in irSIPK plants. Reducing SA levels partially recovered the biomass and fitness deficits of irSIPK plants. We also evaluated whether the increased fitness of plants with reduced SA or JA levels resulted from

Two bHLH-type transcription factors, JA-ASSOCIATED MYC2-LIKE2 and JAM3, are transcriptional repressors and affect male fertility

PubMed Central

Nakata, Masaru; Ohme-Takagi, Masaru

2013-01-01

The jasmonate (JA) plant hormones regulate responses to biotic and abiotic stress and aspects of plant development, including male fertility in Arabidopsis thaliana. The bHLH-type transcription factor JA-ASSOCIATED MYC2-LIKE1 (JAM1) negatively regulates JA signaling and gain-of-function JAM1 transgenic plants have impaired JA-mediated male fertility. Here we report that JAM2 and JAM3, 2 bHLHs closely related to JAM1, also act as transcriptional repressors. Moreover, overexpression of JAM2 and JAM3 also results in reduced male fertility. These results suggest that JAM1, JAM2, and JAM3 act redundantly as negative regulators of JA-mediated male fertility. PMID:24056034

Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood

PubMed Central

Lim, Sang-Dong

2014-01-01

Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products. PMID:26760752

Application of a JA-Ile Biosynthesis Inhibitor to Methyl Jasmonate-Treated Strawberry Fruit Induces Upregulation of Specific MBW Complex-Related Genes and Accumulation of Proanthocyanidins.

PubMed

Delgado, Laura D; Zúñiga, Paz E; Figueroa, Nicolás E; Pastene, Edgar; Escobar-Sepúlveda, Hugo F; Figueroa, Pablo M; Garrido-Bigotes, Adrián; Figueroa, Carlos R

2018-06-13

Fleshy fruits are an important source of anthocyanins and proanthocyanidins (PAs), which protect plants against stress, and their consumption provides beneficial effects for human health. In strawberry fruit, the application of exogenous methyl jasmonate (MeJA) upregulates anthocyanin accumulation, although the relationship between the jasmonate pathway and anthocyanin and PA biosynthesis in fruits remains to be understood. Anthocyanin and PA accumulation is mainly regulated at the transcriptional level through R2R3-MYB and bHLH transcription factors in different plant species and organs. Here, the effect of jarin-1, a specific inhibitor of bioactive JA (jasmonoyl-isoleucine, JA-Ile) biosynthesis, on anthocyanin and PA accumulation was evaluated during strawberry ( Fragaria × ananassa ) fruit development using an in vitro ripening system for 48 h. Also, we observed the effects of MeJA and the application of jarin-1 to MeJA-treated fruits (MeJA + jarin-1 treatment). We assessed changes of expression levels for the JA-Ile and MeJA biosynthetic ( FaJAR1.2 and FaJMT ), JA signaling-related ( FaMYC2 and FaJAZ1 ), MYB-bHLH-WD40 (MBW) complex-related ( FabHLH3/33 , FaMYB9/10/11 , and repressor FaMYB1 ), and anthocyanin and PA biosynthetic (FaANS , FaUFGT , FaANR , and FaLAR ) genes. In addition, the promoter region of MBW complex-related MYB genes was isolated and sequenced. We found a higher redness of strawberry fruit skin and anthocyanin content in MeJA-treated fruits with respect to jarin-1-treated ones concomitant with an upregulation of FaANS and FaUFGT genes. Inversely, the PA content was higher in jarin-1- and MeJA + jarin-1-treated than in MeJA-treated fruits. MeJA + jarin-1 treatment resulted in an upregulation of FaANR and associated transcription factors such as FabHLH33 and FaMYB9/11 along with FaJMT and FaJAR1.2 . Finally, we found JA-responsive elements in the promoter regions of FaMYB1/9/10/11 genes. It is proposed that PA biosynthesis-related genes

JA, a new type of polyunsaturated fatty acid isolated from Juglans mandshurica Maxim, limits the survival and induces apoptosis of heptocarcinoma cells.

PubMed

Gao, Xiu-Li; Lin, Hua; Zhao, Wei; Hou, Ya-Qin; Bao, Yong-Li; Song, Zhen-Bo; Sun, Lu-Guo; Tian, Shang-Yi; Liu, Biao; Li, Yu-Xin

2016-03-01

Juglans mandshurica Maxim (Juglandaceae) is a famous folk medicine for cancer treatment and some natural compounds isolated from it have been studied extensively. Previously we isolated a type of ω-9 polyunsaturated fatty acid (JA) from the bark of J. mandshurica, however little is known about its activity and the underlying mechanisms. In this study, we studied anti-tumor activity of JA on several human cancer cell lines. Results showed that JA is cytotoxic to HepG2, MDA-MB-231, SGC-7901, A549 and Huh7 cells at a concentration exerting minimal toxic effects on L02 cells. The selective toxicity of JA was better than other classical anti-cancer drugs. Further investigation indicated that JA could induce cell apoptosis, characterized by chromatin condensation, DNA fragmentation and activation of the apoptosis-associated proteins such as Caspase-3 and PARP-1. Moreover, we investigated the cellular apoptosis pathway involved in the apoptosis process in HepG2 cells. We found that proteins involved in mitochondrion (cleaved-Caspase-9, Apaf-1, HtrA2/Omi, Bax, and Mitochondrial Bax) and endocytoplasmic reticulum (XBP-1s, GRP78, cleaved-Caspase-7 and cleaved-Caspase-12) apoptotic pathways were up-regulated when cells were treated by JA. In addition, a morphological change in the mitochondrion was detected. Furthermore, we found that JA could inhibit DNA synthesis and induce G2/M cell cycle arrest. The expression of G2-to-M transition related proteins, such as CyclinB1 and phosphorylated-CDK1, were reduced. In contrast, the G2-to-M inhibitor p21 was increased in JA-treated cells. Overall, our results suggest that JA can induce mitochondrion- and endocytoplasmic reticulum-mediated apoptosis, and G2/M phase arrest in HepG2 cells, making it a promising therapeutic agent against hepatoma.

The tomato res mutant which accumulates JA in roots in non-stressed conditions restores cell structure alterations under salinity.

PubMed

Garcia-Abellan, José O; Fernandez-Garcia, Nieves; Lopez-Berenguer, Carmen; Egea, Isabel; Flores, Francisco B; Angosto, Trinidad; Capel, Juan; Lozano, Rafael; Pineda, Benito; Moreno, Vicente; Olmos, Enrique; Bolarin, Maria C

2015-11-01

Jasmonic acid (JA) regulates a wide spectrum of plant biological processes, from plant development to stress defense responses. The role of JA in plant response to salt stress is scarcely known, and even less known is the specific response in root, the main plant organ responsible for ionic uptake and transport to the shoot. Here we report the characterization of the first tomato (Solanum lycopersicum) mutant, named res (restored cell structure by salinity), that accumulates JA in roots prior to exposure to stress. The res tomato mutant presented remarkable growth inhibition and displayed important morphological alterations and cellular disorganization in roots and leaves under control conditions, while these alterations disappeared when the res mutant plants were grown under salt stress. Reciprocal grafting between res and wild type (WT) (tomato cv. Moneymaker) indicated that the main organ responsible for the development of alterations was the root. The JA-signaling pathway is activated in res roots prior to stress, with transcripts levels being even higher in control condition than in salinity. Future studies on this mutant will provide significant advances in the knowledge of JA role in root in salt-stress tolerance response, as well as in the energy trade-off between plant growth and response to stress. © 2015 Scandinavian Plant Physiology Society.

Extending MAM5 Meta-Model and JaCalIV E Framework to Integrate Smart Devices from Real Environments

PubMed Central

2016-01-01

This paper presents the extension of a meta-model (MAM5) and a framework based on the model (JaCalIVE) for developing intelligent virtual environments. The goal of this extension is to develop augmented mirror worlds that represent a real and virtual world coupled, so that the virtual world not only reflects the real one, but also complements it. A new component called a smart resource artifact, that enables modelling and developing devices to access the real physical world, and a human in the loop agent to place a human in the system have been included in the meta-model and framework. The proposed extension of MAM5 has been tested by simulating a light control system where agents can access both virtual and real sensor/actuators through the smart resources developed. The results show that the use of real environment interactive elements (smart resource artifacts) in agent-based simulations allows to minimize the error between simulated and real system. PMID:26926691

Extending MAM5 Meta-Model and JaCalIV E Framework to Integrate Smart Devices from Real Environments.

PubMed

Rincon, J A; Poza-Lujan, Jose-Luis; Julian, V; Posadas-Yagüe, Juan-Luis; Carrascosa, C

2016-01-01

This paper presents the extension of a meta-model (MAM5) and a framework based on the model (JaCalIVE) for developing intelligent virtual environments. The goal of this extension is to develop augmented mirror worlds that represent a real and virtual world coupled, so that the virtual world not only reflects the real one, but also complements it. A new component called a smart resource artifact, that enables modelling and developing devices to access the real physical world, and a human in the loop agent to place a human in the system have been included in the meta-model and framework. The proposed extension of MAM5 has been tested by simulating a light control system where agents can access both virtual and real sensor/actuators through the smart resources developed. The results show that the use of real environment interactive elements (smart resource artifacts) in agent-based simulations allows to minimize the error between simulated and real system.

NtWRKY-R1, a Novel Transcription Factor, Integrates IAA and JA Signal Pathway under Topping Damage Stress in Nicotiana tabacum

PubMed Central

Jin, Weihuan; Zhou, Qi; Wei, Yuanfang; Yang, Jinmiao; Hao, Fengsheng; Cheng, Zhipeng; Guo, Hongxiang; Liu, Weiqun

2018-01-01

Topping damage can induce the nicotine synthesis in tobacco roots, which involves the activation of JA and auxin signal transduction. It remains unclear how these hormone signals are integrated to regulate nicotine synthesis. Here we isolated a transcription factor NtWRKY-R1 from the group IIe of WRKY family and it had strong negative correlation with the expression of putrescine N-methyltransferase, the key enzyme of nicotine synthesis pathway. NtWRKY-R1 was specifically and highly expressed in tobacco roots, and it contains two transcriptional activity domains in the N- and C-terminal. The promoter region of NtWRKY-R1 contains two cis-elements which are responding to JA and auxin signals, respectively. Deletion of NtWRKY-R1 promoter showed that JA and auxin signals were subdued by NtWRKY-R1, and the expression of NtWRKY-R1 was more sensitive to auxin than JA. Furthermore, Yeast two-hybrid experiment demonstrated that NtWRKY-R1 can interact with the actin-binding protein. Our data showed that the intensity of JA and auxin signals can be translated into the expression of NtWRKY-R1, which regulates the balance of actin polymerization and depolymerization through binding actin-binding protein, and then regulates the expression of genes related to nicotine synthesis. The results will help us better understand the function of the WRKY-IIe family in the signaling crosstalk of JA and auxin under damage stress. PMID:29379516

Transcriptome Analysis of ABA/JA-Dual Responsive Genes in Rice Shoot and Root.

PubMed

Kim, Jin-Ae; Bhatnagar, Nikita; Kwon, Soon Jae; Min, Myung Ki; Moon, Seok-Jun; Yoon, In Sun; Kwon, Taek-Ryoun; Kim, Sun Tae; Kim, Beom-Gi

2018-01-01

The phytohormone abscisic acid (ABA) enables plants to adapt to adverse environmental conditions through the modulation of metabolic pathways and of growth and developmental programs. We used comparative microarray analysis to identify genes exhibiting ABA-dependent expression and other hormone-dependent expression among them in Oryza sativa shoot and root. We identified 854 genes as significantly up- or down-regulated in root or shoot under ABA treatment condition. Most of these genes had similar expression profiles in root and shoot under ABA treatment condition, whereas 86 genes displayed opposite expression responses in root and shoot. To examine the crosstalk between ABA and other hormones, we compared the expression profiles of the ABA-dependently regulated genes under several different hormone treatment conditions. Interestingly, around half of the ABA-dependently expressed genes were also regulated by jasmonic acid based on microarray data analysis. We searched the promoter regions of these genes for cis-elements that could be responsible for their responsiveness to both hormones, and found that ABRE and MYC2 elements, among others, were common to the promoters of genes that were regulated by both ABA and JA. These results show that ABA and JA might have common gene expression regulation system and might explain why the JA could function for both abiotic and biotic stress tolerance.

Integrated metabolomic and proteomic analysis reveals systemic responses of Rubrivivax benzoatilyticus JA2 to aniline stress.

PubMed

Mujahid, Md; Prasuna, M Lakshmi; Sasikala, Ch; Ramana, Ch Venkata

2015-02-06

Aromatic amines are widely distributed in the environment and are major environmental pollutants. Although degradation of aromatic amines is well studied in bacteria, physiological adaptations and stress response to these toxic compounds is not yet fully understood. In the present study, systemic responses of Rubrivivax benzoatilyticus JA2 to aniline stress were deciphered using metabolite and iTRAQ-labeled protein profiling. Strain JA2 tolerated high concentrations of aniline (30 mM) with trace amounts of aniline being transformed to acetanilide. GC-MS metabolite profiling revealed aniline stress phenotype wherein amino acid, carbohydrate, fatty acid, nitrogen metabolisms, and TCA (tricarboxylic acid cycle) were modulated. Strain JA2 responded to aniline by remodeling the proteome, and cellular functions, such as signaling, transcription, translation, stress tolerance, transport and carbohydrate metabolism, were highly modulated. Key adaptive responses, such as transcription/translational changes, molecular chaperones to control protein folding, and efflux pumps implicated in solvent extrusion, were induced in response to aniline stress. Proteo-metabolomics indicated extensive rewiring of metabolism to aniline. TCA cycle and amino acid catabolism were down-regulated while gluconeogenesis and pentose phosphate pathways were up-regulated, leading to the synthesis of extracellular polymeric substances. Furthermore, increased saturated fatty acid ratios in membranes due to aniline stress suggest membrane adaptation. The present study thus indicates that strain JA2 employs multilayered responses: stress response, toxic compound tolerance, energy conservation, and metabolic rearrangements to aniline.

Technical Digest Series. Volume 8. Summaries of Papers Presented at the Spatial Light Modulators and Application Topical Meeting Held in South Lake Tahoe, Nevada on June 15-17, 1988.

DTIC Science & Technology

1988-01-01

photoelectromaqnetic effect ir blue or green light by Moore [5], and 1-6 x 10 cm ’/V for the p -i-n + a- Si:Hphotodiode in AMl white light by Crandall [6]. With 10 V...37, 327(1980). 6. R. S. Crandall, Appl. Phys. Lett. 44, 537(1984). 7. R. S. Crandall, J. Appl. Phys. 53, 3350(1982). 8. Tae-Kwan Oh, Ph.D. Thesis ...34Techniques and devices for high-resolution adaptive optics," PhD Thesis , Massachusetts Institute of Technology (1981). 9. J.A, McEwan, A.D. Fisher and J. N

JaK/STAT Inhibition to Prevent Post-Traumatic Epileptogenesis

DTIC Science & Technology

2013-07-31

months 22-28) 2i. Assess mossy fiber sprouting, cell loss and glial proliferation 10 weeks post injury using Timm and Nissl staining (40 mice...1e. Assess protein levels and regional/cellular expression of JaK1 and 2, pSTAT1-5 using fluorescent immunohistochemistry with co- staining for cell...treated with CCI, 10 of which were treated with WP1066. Early post-injury experiments are underway; Timm staining has not revealed mossy fiber

OsMPK3 positively regulates the JA signaling pathway and plant resistance to a chewing herbivore in rice.

PubMed

Wang, Qi; Li, Jiancai; Hu, Lingfei; Zhang, Tongfang; Zhang, Guren; Lou, Yonggen

2013-07-01

KEY MESSAGE : Silencing OsMPK3 decreased elicited JA levels, which subsequently reduced levels of herbivore-induced trypsin protease inhibitors (TrypPIs) and improved the performance of SSB larvae, but did not influence BPH. Mitogen-activated protein kinases (MPKs) are known to play an important role in plant defense by transferring biotic and abiotic signals into programmed cellular responses. However, their functions in the herbivore-induced defense response in rice remain largely unknown. Here, we identified a MPK3 gene from rice, OsMPK3, and found that its expression levels were up-regulated in response to infestation by the larvae of the striped stem borer (SSB) (Chilo suppressalis), to mechanical wounding and to treatment with jasmonic acid (JA), but not to infestation by the brown planthopper (BPH) Nilaparvata lugens or to treatment with salicylic acid. Moreover, mechanical wounding and SSB infestation induced the expression of OsMPK3 strongly and quickly, whereas JA treatment induced the gene more weakly and slowly. Silencing OsMPK3 (ir-mpk3) reduced the expression of the gene by 50-70 %, decreased elicited levels of JA and diminished the expression of a lipoxygenase gene OsHI-LOX and an allene oxide synthase gene OsAOS1. The reduced JA signaling in ir-mpk3 plants decreased the levels of herbivore-induced trypsin protease inhibitors (TrypPIs) and improved the performance of SSB larvae, but did not influence BPH. Our findings suggest that the gene OsMPK3 responds early in herbivore-induced defense and can be regulated by rice plants to activate a specific and appropriate defense response to different herbivores.

No time for candy: passionfruit (Passiflora edulis) plants down-regulate damage-induced extra floral nectar production in response to light signals of competition.

PubMed

Izaguirre, Miriam M; Mazza, Carlos A; Astigueta, María S; Ciarla, Ana M; Ballaré, Carlos L

2013-09-01

Plant fitness is often defined by the combined effects of herbivory and competition, and plants must strike a delicate balance between their ability to capture limiting resources and defend against herbivore attack. Many plants use indirect defenses, such as volatile compounds and extra floral nectaries (EFN), to attract canopy arthropods that are natural enemies of herbivorous organisms. While recent evidence suggests that upon perception of low red to far-red (R:FR) ratios, which signal the proximity of competitors, plants down-regulate resource allocation to direct chemical defenses, it is unknown if a similar phytochrome-mediated response occurs for indirect defenses. We evaluated the interactive effects of R:FR ratio and simulated herbivory on nectar production by EFNs of passion fruit (Passiflora edulis f. flavicarpa). The activity of petiolar EFNs dramatically increased in response to simulated herbivory and hormonal treatment with methyl jasmonate (MeJA). Low R:FR ratios, which induced a classic "shade-avoidance" repertoire of increased stem elongation in P. edulis, strongly suppressed the EFN response triggered by simulated herbivory or MeJA application. Strikingly, the EFN response to wounding and light quality was localized to the branches that received the treatments. In vines like P. edulis, a local response would allow the plants to precisely adjust their light harvesting and defense phenotypes to the local conditions encountered by individual branches when foraging for resources in patchy canopies. Consistent with the emerging paradigm that phytochrome regulation of jasmonate signaling is a central modulator of adaptive phenotypic plasticity, our results demonstrate that light quality is a strong regulator of indirect defenses.

Induction of Shikimic Acid Pathway Enzymes by Light in Suspension Cultured Cells of Parsley (Petroselinum crispum) 1

PubMed Central

McCue, Kent F.; Conn, Eric E.

1990-01-01

Light treatment of suspension cultured cells of parsley (Petroselinum crispum) was shown to increase the activity of the shikimic acid pathway enzyme, 3-deoxy-d-arabino-heptulosonic acid-7-phosphate (DAHP) synthase (EC 4.1.2.15). DAHP synthase activity was assayed for two isoforms, DS-Mn and DS-Co (RJ Ganson, TA d'Amato, RA Jensen [1986] Plant Physiol 82: 203-210). Light increased the enzymatic activity of the plastidic isoform DS-Mn as much as 2-fold, averaging 1.6-fold with >95% confidence. The cytosolic isoform DS-Co was unaffected. Cycloheximide and actinomycin D, translational and transcriptional inhibitors, respectively, both reversed induction of DS-Mn by light suggesting transcriptional regulation of the gene. Chorismate mutase activity was assayed for the two isoforms CM I and CM II (BK Singh, JA Connelly, EE Conn [1985] Arch Biochem Biophys 243: 374-384). Treatment by light did not significantly affect either chorismate mutase isoform. The ratio of the two chorismate mutase isoforms changed during the growth cycle, with an increase in the ratio of plastidic to cytosolic isoforms occurring towards the end of logarithmic growth. PMID:16667741

Stable Isotope-Assisted Metabolic Profiling Reveals Growth Mode Dependent Differential Metabolism and Multiple Catabolic Pathways of l-Phenylalanine in Rubrivivax benzoatilyticus JA2.

PubMed

Mekala, Lakshmi Prasuna; Mohammed, Mujahid; Chintalapati, Sasikala; Chintalapati, Venkata Ramana

2018-01-05

Anoxygenic phototrophic bacteria are metabolically versatile and survive under different growth modes using diverse organic compounds, yet their metabolic diversity is largely unexplored. In the present study, we employed stable-isotope-assisted metabolic profiling to unravel the l-phenylalanine catabolism in Rubrivivax benzoatilyticus JA2 under varying growth modes. Strain JA2 grows under anaerobic and aerobic conditions by utilizing l-phenylalanine as a nitrogen source. Furthermore, ring-labeled 13 C 6 -phenylalanine feeding followed by liquid chromatography-mass spectrometry exometabolite profiling revealed 60 labeled metabolic features (M + 6, M + 12, and M + 18) derived solely from l-phenylalanine, of which 11 were identified, 7 putatively identified, and 42 unidentified under anaerobic and aerobic conditions. However, labeled metabolites were significantly higher in aerobic compared to anaerobic conditions. Furthermore, detected metabolites and enzyme activities indicated multiple l-phenylalanine catabolic routes mainly Ehrlich, homogentisate-dependent melanin, benzenoid, and unidentified pathways operating under anaerobic and aerobic conditions in strain JA2. Interestingly, the study indicated l-phenylalanine-dependent and independent benzenoid biosynthesis in strain JA2 and a differential flux of l-phenylalanine to Ehrlich and benzenoid pathways under anaerobic and aerobic conditions. Additionally, unidentified labeled metabolites strongly suggest the presence of unknown phenylalanine catabolic routes in strain JA2. Overall, the study uncovered the l-phenylalanine catabolic diversity in strain JA2 and demonstrated the potential of stable isotope-assisted metabolomics in unraveling the hidden metabolic repertoire.

Light and abiotic stresses regulate the expression of GDP-L-galactose phosphorylase and levels of ascorbic acid in two kiwifruit genotypes via light-responsive and stress-inducible cis-elements in their promoters.

PubMed

Li, Juan; Liang, Dong; Li, Mingjun; Ma, Fengwang

2013-09-01

Ascorbic acid (AsA) plays an essential role in plants by protecting cells against oxidative damage. GDP-L-galactose phosphorylase (GGP) is the first committed gene for AsA synthesis. Our research examined AsA levels, regulation of GGP gene expression, and how these are related to abiotic stresses in two species of Actinidia (kiwifruit). When leaves were subjected to continuous darkness or light, ABA or MeJA, heat, or a hypoxic environment, we found some correlation between the relative levels of GGP mRNA and AsA concentrations. In transformed tobacco plants, activity of the GGP promoter was induced by all of these treatments. However, the degree of inducibility in the two kiwifruit species differed among the GGP promoter deletions. We deduced that the G-box motif, a light-responsive element, may have an important function in regulating GGP transcripts under various light conditions in both A. deliciosa and A. eriantha. Other elements such as ABRE, the CGTCA motif, and HSE might also control the promoter activities of GGP in kiwifruit. Altogether, these data suggest that GGP expression in the two kiwifruit species is regulated by light or abiotic stress via the relative cis-elements in their promoters. Furthermore, GGP has a critical role in modulating AsA concentrations in kiwifruit species under abiotic stresses.

Aniline Is an Inducer, and Not a Precursor, for Indole Derivatives in Rubrivivax benzoatilyticus JA2

PubMed Central

Mohammed, Mujahid; Ch, Sasikala; Ch, Ramana V.

2014-01-01

Rubrivivax benzoatilyticus JA2 and other anoxygenic photosynthetic bacteria produce indole derivatives when exposed to aniline, a xenobiotic compound. Though this phenomenon has been reported previously, the role of aniline in the production of indoles is still a biochemical riddle. The present study aims at understanding the specific role of aniline (as precursor or stimulator) in the production of indoles and elucidating the biochemical pathway of indoles in aniline-exposed cells by using stable isotope approaches. Metabolic profiling revealed tryptophan accumulation only in aniline exposed cells along with indole 3-acetic acid (IAA) and indole 3-aldehyde (IAld), the two major catabolites of tryptophan. Deuterium labelled aniline feeding studies revealed that aniline is not a precursor of indoles in strain JA2. Further, production of indoles only in aniline-exposed cells suggests that aniline is an indoles stimulator. In addition, production of indoles depended on the presence of a carbon source, and production enhanced when carbon sources were added to the culture. Isotope labelled fumarate feeding identified, fumarate as the precursor of indole, indicating de novo synthesis of indoles. Glyphosate (shikimate pathway inhibitor) inhibited the indoles production, accumulation of tryptophan, IAA and IAld indicating that indoles synthesis in strain JA2 occurs via the de novo shikimate pathway. The up-regulation of anthranilate synthase gene and induction of anthranilate synthase activity correlated well with tryptophan production in strain JA2. Induction of tryptophan aminotransferase and tryptophan 2-monooxygenase activities corroborated well with IAA levels, suggesting that tryptophan catabolism occurs simultaneously in aniline exposed cells. Our study demonstrates that aniline (stress) stimulates tryptophan/indoles synthesis via the shikimate pathway by possibly modulating the metabolic pathway. PMID:24533057

Aniline is an inducer, and not a precursor, for indole derivatives in Rubrivivax benzoatilyticus JA2.

PubMed

Mujahid, Mohammed; Sasikala, Ch; Ramana, Ch V

2014-01-01

Rubrivivax benzoatilyticus JA2 and other anoxygenic photosynthetic bacteria produce indole derivatives when exposed to aniline, a xenobiotic compound. Though this phenomenon has been reported previously, the role of aniline in the production of indoles is still a biochemical riddle. The present study aims at understanding the specific role of aniline (as precursor or stimulator) in the production of indoles and elucidating the biochemical pathway of indoles in aniline-exposed cells by using stable isotope approaches. Metabolic profiling revealed tryptophan accumulation only in aniline exposed cells along with indole 3-acetic acid (IAA) and indole 3-aldehyde (IAld), the two major catabolites of tryptophan. Deuterium labelled aniline feeding studies revealed that aniline is not a precursor of indoles in strain JA2. Further, production of indoles only in aniline-exposed cells suggests that aniline is an indoles stimulator. In addition, production of indoles depended on the presence of a carbon source, and production enhanced when carbon sources were added to the culture. Isotope labelled fumarate feeding identified, fumarate as the precursor of indole, indicating de novo synthesis of indoles. Glyphosate (shikimate pathway inhibitor) inhibited the indoles production, accumulation of tryptophan, IAA and IAld indicating that indoles synthesis in strain JA2 occurs via the de novo shikimate pathway. The up-regulation of anthranilate synthase gene and induction of anthranilate synthase activity correlated well with tryptophan production in strain JA2. Induction of tryptophan aminotransferase and tryptophan 2-monooxygenase activities corroborated well with IAA levels, suggesting that tryptophan catabolism occurs simultaneously in aniline exposed cells. Our study demonstrates that aniline (stress) stimulates tryptophan/indoles synthesis via the shikimate pathway by possibly modulating the metabolic pathway.

Modulation of ethylene- and heat-controlled hyponastic leaf movement in Arabidopsis thaliana by the plant defence hormones jasmonate and salicylate.

PubMed

van Zanten, Martijn; Ritsema, Tita; Polko, Joanna K; Leon-Reyes, Antonio; Voesenek, Laurentius A C J; Millenaar, Frank F; Pieterse, Corné M J; Peeters, Anton J M

2012-04-01

Upward leaf movement (hyponastic growth) is adopted by several plant species including Arabidopsis thaliana, as a mechanism to escape adverse growth conditions. Among the signals that trigger hyponastic growth are, the gaseous hormone ethylene, low light intensities, and supra-optimal temperatures (heat). Recent studies indicated that the defence-related phytohormones jasmonic acid (JA) and salicylic acid (SA) synthesized by the plant upon biotic infestation repress low light-induced hyponastic growth. The hyponastic growth response induced by high temperature (heat) treatment and upon application of the gaseous hormone ethylene is highly similar to the response induced by low light. To test if these environmental signals induce hyponastic growth via parallel pathways or converge downstream, we studied here the roles of Methyl-JA (MeJA) and SA on ethylene- and heat-induced hyponastic growth. For this, we used a time-lapse camera setup. Our study includes pharmacological application of MeJA and SA and biological infestation using the JA-inducing caterpillar Pieris rapae as well as mutants lacking JA or SA signalling components. The data demonstrate that MeJA is a positive, and SA, a negative regulator of ethylene-induced hyponastic growth and that both hormones repress the response to heat. Taking previous studies into account, we conclude that SA is the first among many tested components which is repressing hyponastic growth under all tested inductive environmental stimuli. However, since MeJA is a positive regulator of ethylene-induced hyponastic growth and is inhibiting low light- and heat-induced leaf movement, we conclude that defence hormones control hyponastic growth by affecting stimulus-specific signalling pathways.

Combination of Light and Melatonin Time Cues for Phase Advancing the Human Circadian Clock

PubMed Central

Burke, Tina M.; Markwald, Rachel R.; Chinoy, Evan D.; Snider, Jesse A.; Bessman, Sara C.; Jung, Christopher M.; Wright, Kenneth P.

2013-01-01

Study Objectives: Photic and non-photic stimuli have been shown to shift the phase of the human circadian clock. We examined how photic and non-photic time cues may be combined by the human circadian system by assessing the phase advancing effects of one evening dose of exogenous melatonin, alone and in combination with one session of morning bright light exposure. Design: Randomized placebo-controlled double-blind circadian protocol. The effects of four conditions, dim light (∼1.9 lux, ∼0.6 Watts/m2)-placebo, dim light-melatonin (5 mg), bright light (∼3000 lux, ∼7 Watts/m2)-placebo, and bright light-melatonin on circadian phase was assessed by the change in the salivary dim light melatonin onset (DLMO) prior to and following treatment under constant routine conditions. Melatonin or placebo was administered 5.75 h prior to habitual bedtime and 3 h of bright light exposure started 1 h prior to habitual wake time. Setting: Sleep and chronobiology laboratory environment free of time cues. Participants: Thirty-six healthy participants (18 females) aged 22 ± 4 y (mean ± SD). Results: Morning bright light combined with early evening exogenous melatonin induced a greater phase advance of the DLMO than either treatment alone. Bright light alone and melatonin alone induced similar phase advances. Conclusion: Information from light and melatonin appear to be combined by the human circadian clock. The ability to combine circadian time cues has important implications for understanding fundamental physiological principles of the human circadian timing system. Knowledge of such principles is important for designing effective countermeasures for phase-shifting the human circadian clock to adapt to jet lag, shift work, and for designing effective treatments for circadian sleep-wakefulness disorders. Citation: Burke TM; Markwald RR; Chinoy ED; Snider JA; Bessman SC; Jung CM; Wright Jr KP. Combination of light and melatonin time cues for phase advancing the human circadian

Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus “Ferrovum”

PubMed Central

Ullrich, Sophie R.; Poehlein, Anja; Tischler, Judith S.; González, Carolina; Ossandon, Francisco J.; Daniel, Rolf; Holmes, David S.; Schlömann, Michael; Mühling, Martin

2016-01-01

Background Members of the genus “Ferrovum” are ubiquitously distributed in acid mine drainage (AMD) waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain “Ferrovum myxofaciens” P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus “Ferrovum” is extremely scarce. Objective In order to access the wider genetic pool of the genus “Ferrovum” we sequenced the genome of a “Ferrovum”-containing mixed culture and successfully assembled the almost complete genome sequence of the novel “Ferrovum” strain JA12. Phylogeny and Lifestyle The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct “Ferrovum” species. “Ferrovum” strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that “Ferrovum” strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively. Unique Metabolic Features The potential utilisation of urea by “Ferrovum” strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs “Ferrovum” strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin) and Acidithiobacillus

Early dust formation and a massive progenitor for SN 2011ja?

NASA Astrophysics Data System (ADS)

Andrews, J. E.; Krafton, Kelsie M.; Clayton, Geoffrey C.; Montiel, E.; Wesson, R.; Sugerman, Ben E. K.; Barlow, M. J.; Matsuura, M.; Drass, H.

2016-04-01

SN 2011ja was a bright (I = -18.3) Type II supernova occurring in the nearby edge on spiral galaxy NGC 4945. Flat-topped and multipeaked H α and H β spectral emission lines appear between 64 and 84 d post-explosion, indicating interaction with a disc-like circumstellar medium inclined ˜45° from edge-on. After day 84, an increase in the H- and K-band flux along with heavy attenuation of the red wing of the emission lines are strong indications of early dust formation, likely located in the cool dense shell created between the forward shock of the SN ejecta and the reverse shock created as the ejecta plows into the existing circumstellar material. Radiative transfer modelling reveals both ≈1 × 10-5 M⊙ of pre-existing dust located ˜1016.7 cm away and up to ≈6 × 10-4 M⊙ of newly formed dust. Spectral observations after 1.5 yr reveal the possibility that the fading SN is located within a young (3-6 Myr) massive stellar cluster, which when combined with tentative 56Ni mass estimates of 0.2 M⊙ may indicate a massive (≥25 M⊙) progenitor for SN 2011ja.

New Enhanced Artificial Bee Colony (JA-ABC5) Algorithm with Application for Reactive Power Optimization

PubMed Central

2015-01-01

The standard artificial bee colony (ABC) algorithm involves exploration and exploitation processes which need to be balanced for enhanced performance. This paper proposes a new modified ABC algorithm named JA-ABC5 to enhance convergence speed and improve the ability to reach the global optimum by balancing exploration and exploitation processes. New stages have been proposed at the earlier stages of the algorithm to increase the exploitation process. Besides that, modified mutation equations have also been introduced in the employed and onlooker-bees phases to balance the two processes. The performance of JA-ABC5 has been analyzed on 27 commonly used benchmark functions and tested to optimize the reactive power optimization problem. The performance results have clearly shown that the newly proposed algorithm has outperformed other compared algorithms in terms of convergence speed and global optimum achievement. PMID:25879054

New enhanced artificial bee colony (JA-ABC5) algorithm with application for reactive power optimization.

PubMed

Sulaiman, Noorazliza; Mohamad-Saleh, Junita; Abro, Abdul Ghani

2015-01-01

The standard artificial bee colony (ABC) algorithm involves exploration and exploitation processes which need to be balanced for enhanced performance. This paper proposes a new modified ABC algorithm named JA-ABC5 to enhance convergence speed and improve the ability to reach the global optimum by balancing exploration and exploitation processes. New stages have been proposed at the earlier stages of the algorithm to increase the exploitation process. Besides that, modified mutation equations have also been introduced in the employed and onlooker-bees phases to balance the two processes. The performance of JA-ABC5 has been analyzed on 27 commonly used benchmark functions and tested to optimize the reactive power optimization problem. The performance results have clearly shown that the newly proposed algorithm has outperformed other compared algorithms in terms of convergence speed and global optimum achievement.

Biosynthesis of silver and zinc oxide nanoparticles using Pichia fermentans JA2 and their antimicrobial property

NASA Astrophysics Data System (ADS)

Chauhan, Ritika; Reddy, Arpita; Abraham, Jayanthi

2015-01-01

The development of eco-friendly alternative to chemical synthesis of metal nanoparticles is of great challenge among researchers. The present study aimed to investigate the biological synthesis, characterization, antimicrobial study and synergistic effect of silver and zinc oxide nanoparticles against clinical pathogens using Pichia fermentans JA2. The extracellular biosynthesis of silver and zinc oxide nanoparticles was investigated using Pichia fermentans JA2 isolated from spoiled fruit pulp bought in Vellore local market. The crystalline and stable metallic nanoparticles were characterized evolving several analytical techniques including UV-visible spectrophotometer, X-ray diffraction pattern analysis and FE-scanning electron microscope with EDX-analysis. The biosynthesized metallic nanoparticles were tested for their antimicrobial property against medically important Gram positive, Gram negative and fungal pathogenic microorganisms. Furthermore, the biosynthesized nanoparticles were also evaluated for their increased antimicrobial activities with various commercially available antibiotics against clinical pathogens. The biosynthesized silver nanoparticles inhibited most of the Gram negative clinical pathogens, whereas zinc oxide nanoparticles were able to inhibit only Pseudomonas aeruginosa. The combined effect of standard antibiotic disc and biosynthesized metallic nanoparticles enhanced the inhibitory effect against clinical pathogens. The biological synthesis of silver and zinc oxide nanoparticles is a novel and cost-effective approach over harmful chemical synthesis techniques. The metallic nanoparticles synthesized using Pichia fermentans JA2 possess potent inhibitory effect that offers valuable contribution to pharmaceutical associations.

Paleoarchean and Cambrian observations of the geodynamo in light of new estimates of core thermal conductivity

NASA Astrophysics Data System (ADS)

Tarduno, John; Bono, Richard; Cottrell, Rory

2015-04-01

Recent estimates of core thermal conductivity are larger than prior values by a factor of approximately three. These new estimates suggest that the inner core is a relatively young feature, perhaps as young as 500 million years old, and that the core-mantle heat flux required to drive the early dynamo was greater than previously assumed (Nimmo, 2015). Here, we focus on paleomagnetic studies of two key time intervals important for understanding core evolution in light of the revisions of core conductivity values. 1. Hadean to Paleoarchean (4.4-3.4 Ga). Single silicate crystal paleointensity analyses suggest a relatively strong magnetic field at 3.4-3.45 Ga (Tarduno et al., 2010). Paleointenity data from zircons of the Jack Hills (Western Australia) further suggest the presence of a geodynamo between 3.5 and 3.6 Ga (Tarduno and Cottrell, 2014). We will discuss our efforts to test for the absence/presence of the geodynamo in older Eoarchean and Hadean times. 2. Ediacaran to Early Cambrian (~635-530 Ma). Disparate directions seen in some paleomagnetic studies from this time interval have been interpreted as recording inertial interchange true polar wander (IITPW). Recent single silicate paleomagnetic analyses fail to find evidence for IITPW; instead a reversing field overprinted by secondary magnetizations is defined (Bono and Tarduno, 2015). Preliminary analyses suggest the field may have been unusually weak. We will discuss our on-going tests of the hypothesis that this interval represents the time of onset of inner core growth. References: Bono, R.K. & Tarduno, J.A., Geology, in press (2015); Nimmo, F., Treatise Geophys., in press (2015); Tarduno, J.A., et al., Science (2010); Tarduno, J.A. & Cottrell, R.D., AGU Fall Meeting (2014).

Deep Sequencing Reveals the Effect of MeJA on Scutellarin Biosynthesis in Erigeron breviscapus

PubMed Central

Xiao, Ying; Zhang, Feng; Chen, Jun-feng; Ji, Qian; Tan, He-Xin; Huang, Xin; Feng, Hao; Huang, Bao-Kang; Chen, Wan-Sheng; Zhang, Lei

2015-01-01

Background Erigeron breviscapus, a well-known traditional Chinese medicinal herb, is broadly used in the treatment of cerebrovascular disease. Scutellarin, a kind of flavonoids, is considered as the material base of the pharmaceutical activities in E. breviscapus. The stable and high content of scutellarin is critical for the quality and efficiency of E. breviscapus in the clinical use. Therefore, understanding the molecular mechanism of scutellarin biosynthesis is crucial for metabolic engineering to increase the content of the active compound. However, there is virtually no study available yet concerning the genetic research of scutellarin biosynthesis in E. breviscapus. Results Using Illumina sequencing technology, we obtained over three billion bases of high-quality sequence data and conducted de novo assembly and annotation without prior genome information. A total of 182,527 unigenes (mean length = 738 bp) were found. 63,059 unigenes were functionally annotated with a cut-off E-value of 10−5. Next, a total of 238 (200 up-regulated and 38 down-regulated genes) and 513 (375 up-regulated and 138 down-regulated genes) differentially expressed genes were identified at different time points after methyl jasmonate (MeJA) treatment, which fell into categories of ‘metabolic process’ and ‘cellular process’ using GO database, suggesting that MeJA-induced activities of signal pathway in plant mainly led to re-programming of metabolism and cell activity. In addition, 13 predicted genes that might participate in the metabolism of flavonoids were found by two co-expression analyses in E. breviscapus. Conclusions Our study is the first to provide a transcriptome sequence resource for E. breviscapus plants after MeJA treatment and it reveals transcriptome re-programming upon elicitation. As the result, several putative unknown genes involved in the metabolism of flavonoids were predicted. These data provide a valuable resource for the genetic and genomic studies of

Singlet oxygen triggers chloroplast rupture and cell death in the zeaxanthin epoxidase defective mutant aba1 of Arabidopsis thaliana under high light stress.

PubMed

Sánchez-Corrionero, Álvaro; Sánchez-Vicente, Inmaculada; González-Pérez, Sergio; Corrales, Ascensión; Krieger-Liszkay, Anja; Lorenzo, Óscar; Arellano, Juan B

2017-09-01

The two Arabidopsis thaliana mutants, aba1 and max4, were previously identified as sharing a number of co-regulated genes with both the flu mutant and Arabidopsis cell suspension cultures exposed to high light (HL). On this basis, we investigated whether aba1 and max4 were generating high amounts of singlet oxygen ( 1 O 2 ) and activating 1 O 2 -mediated cell death. Thylakoids of aba1 produced twice as much 1 O 2 as thylakoids of max4 and wild type (WT) plants when illuminated with strong red light. 1 O 2 was measured using the spin probe 2,2,6,6-tetramethyl-4-piperidone hydrochloride. 77-K chlorophyll fluorescence emission spectra of thylakoids revealed lower aggregation of the light harvesting complex II in aba1. This was rationalized as a loss of connectivity between photosystem II (PSII) units and as the main cause for the high yield of 1 O 2 generation in aba1. Up-regulation of the 1 O 2 responsive gene AAA-ATPase was only observed with statistical significant in aba1 under HL. Two early jasmonate (JA)-responsive genes, JAZ1 and JAZ5, encoding for two repressor proteins involved in the negative feedback regulation of JA signalling, were not up-regulated to the WT plant levels. Chloroplast aggregation followed by chloroplast rupture and eventual cell death was observed by confocal imaging of the fluorescence emission of leaf cells of transgenic aba1 plants expressing the chimeric fusion protein SSU-GFP. Cell death was not associated with direct 1 O 2 cytotoxicity in aba1, but rather with a delayed stress response. In contrast, max4 did not show evidence of 1 O 2 -mediated cell death. In conclusion, aba1 may serve as an alternative model to other 1 O 2 -overproducing mutants of Arabidopsis for investigating 1 O 2 -mediated cell death. Copyright © 2017 Elsevier GmbH. All rights reserved.

Improper excess light energy dissipation in Arabidopsis results in a metabolic reprogramming

PubMed Central

Frenkel, Martin; Külheim, Carsten; Jänkänpää, Hanna Johansson; Skogström, Oskar; Dall'Osto, Luca; Ågren, Jon; Bassi, Roberto; Moritz, Thomas; Moen, Jon; Jansson, Stefan

2009-01-01

Background Plant performance is affected by the level of expression of PsbS, a key photoprotective protein involved in the process of feedback de-excitation (FDE), or the qE component of non-photochemical quenching, NPQ. Results In studies presented here, under constant laboratory conditions the metabolite profiles of leaves of wild-type Arabidopsis thaliana and plants lacking or overexpressing PsbS were very similar, but under natural conditions their differences in levels of PsbS expression were associated with major changes in metabolite profiles. Some carbohydrates and amino acids differed ten-fold in abundance between PsbS-lacking mutants and over-expressers, with wild-type plants having intermediate amounts, showing that a metabolic shift had occurred. The transcriptomes of the genotypes also varied under field conditions, and the genes induced in plants lacking PsbS were similar to those reportedly induced in plants exposed to ozone stress or treated with methyl jasmonate (MeJA). Genes involved in the biosynthesis of JA were up-regulated, and enzymes involved in this pathway accumulated. JA levels in the undamaged leaves of field-grown plants did not differ between wild-type and PsbS-lacking mutants, but they were higher in the mutants when they were exposed to herbivory. Conclusion These findings suggest that lack of FDE results in increased photooxidative stress in the chloroplasts of Arabidopsis plants grown in the field, which elicits a response at the transcriptome level, causing a redirection of metabolism from growth towards defence that resembles a MeJA/JA response. PMID:19171025

Lighting: Green Light.

ERIC Educational Resources Information Center

Maniccia, Dorine

2003-01-01

Explains that by using sustainable (green) building practices, schools and universities can make their lighting systems more efficient, noting that embracing green design principles can help schools attract students. Discusses lighting-control technologies (occupancy sensing technology, daylighting technology, and scheduling based technologies),…

Unclassified Publications of Lincoln Laboratory. Volume 5

DTIC Science & Technology

1975-12-15

10 TN-1974-36 LIGHT - EMITTING DIODES (LED) JA-4295 LIGHT SCATTERING JA-4456 LINCOLN DIGITAL VOICE TERMINAL TN-1975-53, TN-1975-65 LINCOLN...Hinkley J. O. Sample G. Dresselhaus T. C. Harman J. P. McVittie J. Filson p-n Junction PbSi_xSex Photo- J. P. Donnelly diodes Fabricated by Se...Room-Temperature Operation of GalnAsP/lnP Double- Heterostructure Diode Lasers Emitting at 1.1 (im Transparent Heat Mirrors for Solar-Energy

Smooth light extraction in lighting optical fibre

NASA Astrophysics Data System (ADS)

Fernandez-Balbuena, A. A.; Vazquez-Molini, D.; Garcia-Botella, A.; Martinez-Anton, J. C.; Bernabeu, E.

2011-10-01

Recent advances in LED technology have relegated the use of optical fibre for general lighting, but there are several applications where it can be used as scanners lighting systems, daylight, cultural heritage lighting, sensors, explosion risky spaces, etc. Nowadays the use of high intensity LED to inject light in optical fibre increases the possibility of conjugate fibre + LED for lighting applications. New optical fibres of plastic materials, high core diameter up to 12.6 mm transmit light with little attenuation in the visible spectrum but there is no an efficient and controlled way to extract the light during the fibre path. Side extracting fibres extracts all the light on 2π angle so is not well suited for controlled lighting. In this paper we present an extraction system for mono-filament optical fibre which provides efficient and controlled light distribution. These lighting parameters can be controlled with an algorithm that set the position, depth and shape of the optical extraction system. The extraction system works by total internal reflection in the core of the fibre with high efficiency and low cost. A 10 m length prototype is made with 45° sectional cuts in the fibre core as extraction system. The system is tested with a 1W white LED illuminator in one side.

The design of the light-flash warning light

NASA Astrophysics Data System (ADS)

Wang, Junli

2018-05-01

In today's society, the warning light has been used widely in people's daily life and various industries and agricultures. It is important to protect people's life and security. Light-flashing warning light is a kind of warning light control equipment which can control warning light automatically open and work in the state of blinking after dark, and it can automatically shut down after the dawn. It can achieve the flashing light automatic control and dual function. At present, light-flashing warning lights are mainly used in the projects of municipal construction. It is helpful to warn people and vehicles that passed in the construction site and ensure personal safety through using light-flashing warning light. Its design is simple, its performance is stable and it is also very convince to use it.

Concept of white light in stage lighting

NASA Astrophysics Data System (ADS)

Rinaldi, Mauricio R.

2002-06-01

In perceiving objects, generally we see them in a white light situation. But, actually, there is not an absolute white, in such a manner that the different light sources have a determined kind of white, what it is known as color temperature. Even the white light may be of different kinds (different color temperature), the individual mind tends to perceive it as the same kind of white, that is to say, there is in our mind a psychological function by which we operate an integration in the perception in order to do the object perceptually invariable. On the other hand, it is a common practice in stage lighting to use color light sources. It is a well known phenomenon that a color of light produces a change in the object color perception. However, when we go to theater, we see the objects as having their real color, even if the lighting is not white. In this paper the concept of white light in stage lighting is presented, showing its possibilities of aesthetical expression.

The Combined Effects of Ethylene and MeJA on Metabolic Profiling of Phenolic Compounds in Catharanthus roseus Revealed by Metabolomics Analysis

PubMed Central

Liu, Jia; Liu, Yang; Wang, Yu; Zhang, Zhong-Hua; Zu, Yuan-Gang; Efferth, Thomas; Tang, Zhong-Hua

2016-01-01

Phenolic compounds belong to a class of secondary metabolites and are implicated in a wide range of responsive mechanisms in plants triggered by both biotic and abiotic elicitors. In this study, we approached the combinational effects of ethylene and MeJA (methyl jasmonate) on phenolic compounds profiles and gene expressions in the medicinal plant Catharanthus roseus. In virtue of a widely non-targeted metabolomics method, we identified a total of 34 kinds of phenolic compounds in the leaves, composed by 7 C6C1-, 11 C6C3-, and 16 C6C3C6 compounds. In addition, 7 kinds of intermediates critical for the biosynthesis of phenolic compounds and alkaloids were identified and discussed with phenolic metabolism. The combinational actions of ethylene and MeJA effectively promoted the total phenolic compounds, especially the C6C1 compounds (such as salicylic acid, benzoic acid) and C6C3 ones (such as cinnamic acid, sinapic acid). In contrast, the C6C3C6 compounds displayed a notably inhibitory trend in this case. Subsequently, the gene-to-metabolite networks were drawn up by searching for correlations between the expression profiles of 5 gene tags and the accumulation profiles of 41 metabolite peaks. Generally, we provide an insight into the controlling mode of ethylene-MeJA combination on phenolic metabolism in C. roseus leaves. PMID:27375495

The Combined Effects of Ethylene and MeJA on Metabolic Profiling of Phenolic Compounds in Catharanthus roseus Revealed by Metabolomics Analysis.

PubMed

Liu, Jia; Liu, Yang; Wang, Yu; Zhang, Zhong-Hua; Zu, Yuan-Gang; Efferth, Thomas; Tang, Zhong-Hua

2016-01-01

Phenolic compounds belong to a class of secondary metabolites and are implicated in a wide range of responsive mechanisms in plants triggered by both biotic and abiotic elicitors. In this study, we approached the combinational effects of ethylene and MeJA (methyl jasmonate) on phenolic compounds profiles and gene expressions in the medicinal plant Catharanthus roseus. In virtue of a widely non-targeted metabolomics method, we identified a total of 34 kinds of phenolic compounds in the leaves, composed by 7 C6C1-, 11 C6C3-, and 16 C6C3C6 compounds. In addition, 7 kinds of intermediates critical for the biosynthesis of phenolic compounds and alkaloids were identified and discussed with phenolic metabolism. The combinational actions of ethylene and MeJA effectively promoted the total phenolic compounds, especially the C6C1 compounds (such as salicylic acid, benzoic acid) and C6C3 ones (such as cinnamic acid, sinapic acid). In contrast, the C6C3C6 compounds displayed a notably inhibitory trend in this case. Subsequently, the gene-to-metabolite networks were drawn up by searching for correlations between the expression profiles of 5 gene tags and the accumulation profiles of 41 metabolite peaks. Generally, we provide an insight into the controlling mode of ethylene-MeJA combination on phenolic metabolism in C. roseus leaves.

Explaining the variability of Photochemical Reflectance Index (PRI): deconvolution of variability related to Light Use Efficiency and Canopy attributes.

NASA Astrophysics Data System (ADS)

Merlier, Elodie; Hmimina, Gabriel; Dufrêne, Eric; Soudani, Kamel

2014-05-01

The Photochemical Reflectance Index (PRI) was designed as a proxy of the state of xanthophyll cycle which is used as a response of plants to excess of light (Gamon et al., 1990; 1992). Strong relationships between PRI and LUE were shown at leaf and canopy scales and over a wide range of species (Garbulsky et al., 2011). However, its use at canopy scale was shown to be significantly hampered by effects of confounding factors such as the PRI sensitivity to leaf pigment content (Gamon et al. 2001; Nakaji et al. 2006) and to canopy structure (Hilker et al. 2008). Several approaches aimed at correcting such effects and recent works focused on the deconvolution of LUE related and LUE unrelated PRI variability (Rahimzadeh-Bajgiran et al. 2012).In this study, the PRI variability at canopy scale is investigated over two years on three species (Fagus sylvatica, Quercus robur and Pinus sylvestris) growing under two water regimes. At daily scale, PRI variability is mainly explained by radiation conditions. As already reported at leaf scale in Hmimina et al. (2014), analysis of PRI responses to incoming photosynthetically active radiation over seasonal scale allowed to separate two sources of variability : a constitutive variability mainly related to canopy structure and leaf chlorophyll content and a facultative variability mainly related to LUE and soil moisture content. These results highlight the composite nature of PRI signal measured at canopy scale and the importance of disentangling its sources of variability in order to accurately assess ecosystem light use efficiency. Gamon JA, Field CB, Bilger W, Björkman O, Fredeen AL, Peñuelas J. 1990. Remote sensing of the xanthophyll cycle and chlorophyll fluorescence in sunflower leaves and canopies. Oecologia 85, 1-7. Gamon JA, Field CB, Fredeen A AL, Thayer S. 2001. Assessing photosynthetic downregulation in sunflower stands with an optically-based model. Photosynthesis Research 67, 113-125. Gamon JA, Peñuelas J, Field CB

Lighting

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

McKay, H.N.

The lighting section of ASHRAE standard 90.1 is discussed. It applies to all new buildings except low-rise residential, while excluding specialty lighting applications such as signage, art exhibits, theatrical productions, medical and dental tasks, and others. In addition, lighting for indoor plant growth is excluded if designed to operate only between 10 p.m. and 6 a.m. Lighting allowances for the interior of a building are determined by the use of the system performance path unless the space functions are not fully known, such as during the initial stages of design or for speculative buildings. In such cases, the prescriptive pathmore » is available. Lighting allowances for the exterior of all buildings are determined by a table of unit power allowances. A new addition the exterior lighting procedure is the inclusion of facade lighting. However, it is no longer possible to trade-off power allotted for the exterior with the interior of a building or vice versa. A significant change is the new emphasis on lighting controls.« less

Bili lights

MedlinePlus

Phototherapy for jaundice; Bilirubin - bili lights; Neonatal care - bili lights; Newborn care - bili lights ... Phototherapy involves shining fluorescent light from the bili lights on bare skin. A specific wavelength of light can break down bilirubin into a form that ...

Light extraction from organic light-emitting diodes for lighting applications by sand-blasting substrates.

PubMed

Chen, Shuming; Kwok, Hoi Sing

2010-01-04

Light extraction from organic light-emitting diodes (OLEDs) by scattering the light is one of the effective methods for large-area lighting applications. In this paper, we present a very simple and cost-effective method to rough the substrates and hence to scatter the light. By simply sand-blasting the edges and back-side surface of the glass substrates, a 20% improvement of forward efficiency has been demonstrated. Moreover, due to scattering effect, a constant color over all viewing angles and uniform light pattern with Lambertian distribution has been obtained. This simple and cost-effective method may be suitable for mass production of large-area OLEDs for lighting applications.

Organic light emitting diode with light extracting electrode

DOEpatents

Bhandari, Abhinav; Buhay, Harry

2017-04-18

An organic light emitting diode (10) includes a substrate (20), a first electrode (12), an emissive active stack (14), and a second electrode (18). At least one of the first and second electrodes (12, 18) is a light extracting electrode (26) having a metallic layer (28). The metallic layer (28) includes light scattering features (29) on and/or in the metallic layer (28). The light extracting features (29) increase light extraction from the organic light emitting diode (10).

Changes in ABA, IAA and JA levels during calyx, fruit and leaves development in cape gooseberry plants (Physalis peruviana L.).

PubMed

Álvarez-Flórez, F; López-Cristoffanini, C; Jáuregui, O; Melgarejo, L M; López-Carbonell, M

2017-06-01

Changes in abscisic acid (ABA), indole-3-acetic acid (IAA) and jasmonic acid (JA) content in developing calyx, fruits and leaves of Physalis peruviana L. plants were analysed. Plant hormones have been widely studied for their roles in the regulation of various aspects related to plant development and, in particular, into their action during development and ripening of fleshly fruits. The obtained evidences suggest that the functions of these hormones are no restricted to a particular development stage, and more than one hormone is involved in controlling various aspects of plant development. Our results will contribute to understand the role of these hormones during growth and development of calyx, fruits and leaves in cape gooseberry plants. This work offers a good, quickly and efficiently protocol to extract and quantify simultaneously ABA, IAA and JA in different tissues of cape gooseberry plants. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

"First Light" Approaches for Fourth VLT Unit Telescope

NASA Astrophysics Data System (ADS)

2000-08-01

These days, the ESO staff at Paranal is having a strong feeling of "déja-vu". Only seven months after the third 8.2-m VLT Unit Telescope, MELIPAL , achieved "First Light", this crucial moment is now rapidly approaching for YEPUN , the fourth and last of the giants at the ESO observatory. Following successful coating with a thin layer of aluminium in early June 2000, the 8.2-m primary Zerodur mirror (M1) was placed in its supporting cell and safely attached to the mechanical structure of YEPUN on July 31. On August 26, the 1.1-m M2 Beryllium Mirror for YEPUN was coated. Again, this delicate operation went very well and the measured reflectivity was excellent, about 91%. The M2 mirror and its support were then assembled and successfully installed at the telescope on Sunday, August 27. Before the optical mirrors were installed, and with dummies in their place, careful tests were made of most telescope functions. In particular, this included accurate balancing of the 450-tonnes telescope frame on its hydrostatic oil bearings, as well as precise adjustment of all motions. It now remains for the ESO engineers to do the final performance optimization of the entire telescope. The work on the fourth telescope has been particularly noticeable because a large proportion of the assembly, integration, tuning and testing was organised and executed by ESOs young group of capable engineers and technicians. As the engineering staff at Paranal has grown and during the earlier work on the first three telescopes, they have been acquiring the necessary expertise to autonomously integrate and maintain the 8.2-m telescopes. During the coming "First Light" observations, light from the selected celestial objects will be registered by the VLT Test Camera at the Cassegrain Focus. This comparatively simple instrument was also used for the consecutive "First Light" events for ANTU ( May 1998 ), KUEYEN ( March 1999 ) and MELIPAL ( January 2000 ). It is mounted on the telescope's optical axis

49 CFR 234.219 - Gate arm lights and light cable.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Gate arm lights and light cable. 234.219 Section....219 Gate arm lights and light cable. Each gate arm light shall be maintained in such condition to be properly visible to approaching highway users. Lights and light wire shall be secured to the gate arm. ...

49 CFR 234.219 - Gate arm lights and light cable.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Gate arm lights and light cable. 234.219 Section....219 Gate arm lights and light cable. Each gate arm light shall be maintained in such condition to be properly visible to approaching highway users. Lights and light wire shall be secured to the gate arm. ...

49 CFR 234.219 - Gate arm lights and light cable.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Gate arm lights and light cable. 234.219 Section....219 Gate arm lights and light cable. Each gate arm light shall be maintained in such condition to be properly visible to approaching highway users. Lights and light wire shall be secured to the gate arm. ...

Light Visor

NASA Technical Reports Server (NTRS)

1993-01-01

Seasonal Affective Disorder is a form of depression brought on by reduced light. For some people, this can lead to clinical depression. NASA has conducted research in light therapy and employs it to help astronauts adjust internal rhythms during orbital flight. Dr. George Brainard, a medical researcher and NASA consultant, has developed a portable light therapy device, which is commercially available. The Light Visor allows continuous light therapy and can be powered by either batteries or electricity. Dr. Brainard continues to research various aspects of light therapy.

Light Trapping with Silicon Light Funnel Arrays

PubMed Central

Nissan, Yuval; Gabay, Tamir; Shalev, Gil

2018-01-01

Silicon light funnels are three-dimensional subwavelength structures in the shape of inverted cones with respect to the incoming illumination. Light funnel (LF) arrays can serve as efficient absorbing layers on account of their light trapping capabilities, which are associated with the presence of high-density complex Mie modes. Specifically, light funnel arrays exhibit broadband absorption enhancement of the solar spectrum. In the current study, we numerically explore the optical coupling between surface light funnel arrays and the underlying substrates. We show that the absorption in the LF array-substrate complex is higher than the absorption in LF arrays of the same height (~10% increase). This, we suggest, implies that a LF array serves as an efficient surface element that imparts additional momentum components to the impinging illumination, and hence optically excites the substrate by near-field light concentration, excitation of traveling guided modes in the substrate, and mode hybridization. PMID:29562685

Stray-light suppression in a reflecting white-light coronagraph

NASA Technical Reports Server (NTRS)

Romoli, Marco; Weiser, Heinz; Gardner, Larry D.; Kohl, John L.

1993-01-01

An analysis of stray-light suppression in the white-light channel of the Ultraviolet Coronagraph Spectrometer experiment for the Solar and Heliospheric Observatory is reported. The white-light channel consists of a reflecting telescope with external and internal occultation and a polarimeter section. Laboratory tests and analytical methods are used to perform the analysis. The various stray-light contributions are classified in two main categories: the contribution from sunlight that passes directly through the entrance aperture and the contribution of sunlight that is diffracted by the edges of the entrance aperture. Values of the stray-light contributions from various sources and the total stray-light level for observations at heliocentric heights from 1.4 to 5 solar radii are derived. Anticipated signal-to-stray-light ratios are presented together with the effective stray-light rejection by the polarimeter, demonstrating the efficacy of the stray-light suppression design.

The International Year of Light and Light-based Technologies

NASA Astrophysics Data System (ADS)

Pendrill, Ann-Marie

2015-05-01

I report on the opening ceremony of the International Year of Light and Light-based Technologies 2015 (IYL2015), which took place at the UNESCO headquarters in Paris, France, on 19-20 January 2015. Over the two days, more than 1000 participants from all over the world learned more about the fundamental properties of light and advanced photonics applications, the history of optics and its applications through the centuries, light poverty and light pollution, and light for everyday life, health and research.

Battery Charge Affects the Stability of Light Intensity from Light-emitting Diode Light-curing Units.

PubMed

Tongtaksin, A; Leevailoj, C

This study investigated the influence of battery charge levels on the stability of light-emitting diode (LED) curing-light intensity by measuring the intensity from fully charged through fully discharged batteries. The microhardness of resin composites polymerized by the light-curing units at various battery charge levels was measured. The light intensities of seven fully charged battery LED light-curing units-1) LY-A180, 2) Bluephase, 3) Woodpecker, 4) Demi Plus, 5) Saab II, 6) Elipar S10, and 7) MiniLED-were measured with a radiometer (Kerr) after every 10 uses (20 seconds per use) until the battery was discharged. Ten 2-mm-thick cylindrical specimens of A3 shade nanofilled resin composite (PREMISE, Kerr) were prepared per LED light-curing unit group. Each specimen was irradiated by the fully charged light-curing unit for 20 seconds. The LED light-curing units were then used until the battery charge fell to 50%. Specimens were prepared again as described above. This was repeated again when the light-curing units' battery charge fell to 25% and when the light intensity had decreased to 400 mW/cm 2 . The top/bottom surface Knoop hardness ratios of the specimens were determined. The microhardness data were analyzed by one-way analysis of variance with Tukey test at a significance level of 0.05. The Pearson correlation coefficient was used to determine significant correlations between surface hardness and light intensity. We found that the light intensities of the Bluephase, Demi Plus, and Elipar S10 units were stable. The intensity of the MiniLED unit decreased slightly; however, it remained above 400 mW/cm 2 . In contrast, the intensities of the LY-A180, Woodpecker, and Saab II units decreased below 400 mW/cm 2 . There was also a significant decrease in the surface microhardnesses of the resin composite specimens treated with MiniLED, LY-A180, Woodpecker, and Saab II. In conclusion, the light intensity of several LED light-curing units decreased as the battery was

Evaluation of light-emitting diode beacon light fixtures.

DOT National Transportation Integrated Search

2009-12-01

Rotating beacons containing filament light sources have long been used on highway maintenance trucks : to indicate the presence of the truck to other drivers. Because of advances in light-emitting diode (LED) : technologies, flashing lights containin...

3. View from former light tower to Cape Elizabeth Light ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View from former light tower to Cape Elizabeth Light Tower, view northeast, southwest side of Cape Elizabeth Tower - Cape Elizabeth Light Station, Near Two Lights State Park at end of Two Lights Road, off State Highway 77, Cape Elizabeth, Cumberland County, ME

Optimization of light quality from color mixing light-emitting diode systems for general lighting

NASA Astrophysics Data System (ADS)

Thorseth, Anders

2012-03-01

Given the problem of metamerisms inherent in color mixing in light-emitting diode (LED) systems with more than three distinct colors, a method for optimizing the spectral output of multicolor LED system with regards to standardized light quality parameters has been developed. The composite spectral power distribution from the LEDs are simulated using spectral radiometric measurements of single commercially available LEDs for varying input power, to account for the efficiency droop and other non-linear effects in electrical power vs. light output. The method uses electrical input powers as input parameters in a randomized steepest decent optimization. The resulting spectral power distributions are evaluated with regard to the light quality using the standard characteristics: CIE color rendering index, correlated color temperature and chromaticity distance. The results indicate Pareto optimal boundaries for each system, mapping the capabilities of the simulated lighting systems with regard to the light quality characteristics.

Light emitting diodes as a plant lighting source

NASA Technical Reports Server (NTRS)

Bula, R. J.; Tennessen, D. J.; Morrow, R. C.; Tibbitts, T. W.

1994-01-01

Electroluminescence in solid materials is defined as the generation of light by the passage of an electric current through a body of solid material under an applied electric field. A specific type of electroluminescence, first noted in 1923, involves the generation of photons when electrons are passed through a p-n junction of certain solid materials (junction of a n-type semiconductor, an electron donor, and a p-type semiconductor, an electron acceptor). The development of this light emitting semiconductor technology dates back less than 30 years. During this period of time, the LED has evolved from a rare and expensive light generating device to one of the most widely used electronic components. A number of LED characteristics are of considerable importance in selecting a light source for plant lighting in a controlled environment facility. Of particular importance is the characteristic that light is generated by an LED at a rate far greater than the corresponding thermal radiation predicted by the bulk temperature of the device as defined by Plank's radiation law. This is in sharp contrast to other light sources, such as an incandescent or high intensity discharge lamp. A plant lighting system for controlled environments must provide plants with an adequate flux of photosynthetically active radiation, plus providing photons in the spectral regions that are involved in the photomorphogenic and phototropic responses that result in normal plant growth and development. Use of light sources that emit photons over a broad spectral range generally meet these two lighting requirements. Since the LED's emit over specific spectral regions, they must be carefully selected so that the levels of photsynthetically active and photomorphogenic and phototropic radiation meet these plant requirements.

Polarized light modulates light-dependent magnetic compass orientation in birds.

PubMed

Muheim, Rachel; Sjöberg, Sissel; Pinzon-Rodriguez, Atticus

2016-02-09

Magnetoreception of the light-dependent magnetic compass in birds is suggested to be mediated by a radical-pair mechanism taking place in the avian retina. Biophysical models on magnetic field effects on radical pairs generally assume that the light activating the magnetoreceptor molecules is nondirectional and unpolarized, and that light absorption is isotropic. However, natural skylight enters the avian retina unidirectionally, through the cornea and the lens, and is often partially polarized. In addition, cryptochromes, the putative magnetoreceptor molecules, absorb light anisotropically, i.e., they preferentially absorb light of a specific direction and polarization, implying that the light-dependent magnetic compass is intrinsically polarization sensitive. To test putative interactions between the avian magnetic compass and polarized light, we developed a spatial orientation assay and trained zebra finches to magnetic and/or overhead polarized light cues in a four-arm "plus" maze. The birds did not use overhead polarized light near the zenith for sky compass orientation. Instead, overhead polarized light modulated light-dependent magnetic compass orientation, i.e., how the birds perceive the magnetic field. Birds were well oriented when tested with the polarized light axis aligned parallel to the magnetic field. When the polarized light axis was aligned perpendicular to the magnetic field, the birds became disoriented. These findings are the first behavioral evidence to our knowledge for a direct interaction between polarized light and the light-dependent magnetic compass in an animal. They reveal a fundamentally new property of the radical pair-based magnetoreceptor with key implications for how birds and other animals perceive the Earth's magnetic field.

Light and Libraries.

ERIC Educational Resources Information Center

Scherer, Jeffrey

1999-01-01

Addresses how to integrate various types of light within the context of library design. Discusses light basics; the light spectrum; light measurement; reflectance; glare and brightness ratio; daylighting; electric lighting; and computer screens and lighting. Includes a checklist for plan review. (Author/LRW)

Light Converting Inorganic Phosphors for White Light-Emitting Diodes

PubMed Central

Chen, Lei; Lin, Chun-Che; Yeh, Chiao-Wen; Liu, Ru-Shi

2010-01-01

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 near-ultraviolet (nUV) LEDs) and photoluminescence phosphors. These solid-state LED lamps, rather than organic light emitting diode (OLED) or polymer light-emitting diode (PLED), 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. To meet with the further requirement of high color rendering index, warm light with low color temperature, high thermal stability and higher energy efficiency for WLEDs, new phosphors that can absorb excitation energy from blue or nUV LEDs and generate visible emissions efficiently are desired. The criteria of choosing the best phosphors, for blue (450−480 nm) and nUV (380−400 nm) LEDs, strongly depends on the absorption and emission of the phosphors. Moreover, the balance of light between the emission from blue-nUV LEDs and the emissions from phosphors (such as yellow from Y3Al5O12:Ce3+) is important to obtain white light with proper color rendering index and color temperature. Here, we will review the status of phosphors for LEDs and prospect the future development.

Polarized light modulates light-dependent magnetic compass orientation in birds

PubMed Central

Muheim, Rachel; Sjöberg, Sissel; Pinzon-Rodriguez, Atticus

2016-01-01

Magnetoreception of the light-dependent magnetic compass in birds is suggested to be mediated by a radical-pair mechanism taking place in the avian retina. Biophysical models on magnetic field effects on radical pairs generally assume that the light activating the magnetoreceptor molecules is nondirectional and unpolarized, and that light absorption is isotropic. However, natural skylight enters the avian retina unidirectionally, through the cornea and the lens, and is often partially polarized. In addition, cryptochromes, the putative magnetoreceptor molecules, absorb light anisotropically, i.e., they preferentially absorb light of a specific direction and polarization, implying that the light-dependent magnetic compass is intrinsically polarization sensitive. To test putative interactions between the avian magnetic compass and polarized light, we developed a spatial orientation assay and trained zebra finches to magnetic and/or overhead polarized light cues in a four-arm “plus” maze. The birds did not use overhead polarized light near the zenith for sky compass orientation. Instead, overhead polarized light modulated light-dependent magnetic compass orientation, i.e., how the birds perceive the magnetic field. Birds were well oriented when tested with the polarized light axis aligned parallel to the magnetic field. When the polarized light axis was aligned perpendicular to the magnetic field, the birds became disoriented. These findings are the first behavioral evidence to our knowledge for a direct interaction between polarized light and the light-dependent magnetic compass in an animal. They reveal a fundamentally new property of the radical pair-based magnetoreceptor with key implications for how birds and other animals perceive the Earth’s magnetic field. PMID:26811473

49 CFR 234.219 - Gate arm lights and light cable.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Gate arm lights and light cable. 234.219 Section... Maintenance, Inspection, and Testing Maintenance Standards § 234.219 Gate arm lights and light cable. Each gate arm light shall be maintained in such condition to be properly visible to approaching highway...

49 CFR 234.219 - Gate arm lights and light cable.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Gate arm lights and light cable. 234.219 Section... Maintenance, Inspection, and Testing Maintenance Standards § 234.219 Gate arm lights and light cable. Each gate arm light shall be maintained in such condition to be properly visible to approaching highway...

Light Pollution

ERIC Educational Resources Information Center

Riegel, Kurt W.

1973-01-01

Outdoor lighting is light pollution which handicaps certain astronomical programs. Protective measures must be adopted by the government to aid observational astronomy without sacrificing legitimate outdoor lighting needs. (PS)

Light guide technology: using light to enhance safety

NASA Astrophysics Data System (ADS)

Lerner, William S.

2009-05-01

When used to detect extreme temperatures in harsh environments, warning devices have been placed at a distance from the "danger zone" for several reasons. The inability to mix electricity with flammable, caustic, liquid or volatile substances, the limited heat tolerances exhibited by most light sources, and the susceptibility of light sources to damage from vibration, have made the placement of a warning light directly within these harsh environments impossible. This paper describes a system that utilizes a beam of light to provide just such a warning. This system can be used with hard-wired or wireless sensors, side-light illumination, image projection and image transfer. The entire system may be self-contained and portable.

Organic light emitting diode with light extracting layer

DOEpatents

Lu, Songwei

2016-06-14

A light extraction substrate includes a glass substrate having a first surface and a second surface. A light extraction layer is formed on at least one of the surfaces. The light extraction layer is a coating, such as a silicon-containing coating, incorporating nanoparticles.

OLED lighting devices having multi element light extraction and luminescence conversion layer

DOEpatents

Krummacher, Benjamin Claus; Antoniadis, Homer

2010-11-16

An apparatus such as a light source has a multi element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

Hybrid daylight/light-emitting diode illumination system for indoor lighting.

PubMed

Ge, Aiming; Qiu, Peng; Cai, Jinlin; Wang, Wei; Wang, Junwei

2014-03-20

A hybrid illumination method using both daylight and light-emitting diodes (LEDs) for indoor lighting is presented in this study. The daylight can be introduced into the indoor space by a panel-integration system. The daylight part and LEDs are combined within a specific luminaire that can provide uniform illumination. The LEDs can be turned on and dimmed through closed-loop control when the daylight illuminance is inadequate. We simulated the illumination and calculated the indoor lighting efficiency of our hybrid daylight and LED lighting system, and compared this with that of LED and fluorescent lighting systems. Simulation results show that the efficiency of the hybrid daylight/LED illumination method is better than that of LED and traditional lighting systems, under the same lighting conditions and lighting time; the method has hybrid lighting average energy savings of T5 66.28%, and that of the LEDs is 41.62%.

Perfect Lighting for Facial Photography in Aesthetic Surgery: Ring Light.

PubMed

Dölen, Utku Can; Çınar, Selçuk

2016-04-01

Photography is indispensable for plastic surgery. On-camera flashes can result in bleached out detail and colour. This is why most of the plastic surgery clinics prefer studio lighting similar to professional photographers'. In this article, we want to share a simple alternative to studio lighting that does not need extra space: Ring light. We took five different photographs of the same person with five different camera and lighting settings: Smartphone and ring light; point and shoot camera and on-camera flash; point and shoot camera and studio lighting; digital single-lens reflex (DLSR) camera and studio lighting; DSLR and ring light. Then, those photographs were assessed objectively with an online survey of five questions answered by three distinct populations: plastic surgeons (n: 28), professional portrait photographers (n: 24) and patients (n: 22) who had facial aesthetic procedures. Compared to the on-camera flash, studio lighting better showed the wrinkles of the subject. The ring light facilitated the perception of the wrinkles by providing homogenous soft light in a circular shape rather than bursting flashes. The combination of a DSLR camera and ring light gave the oldest looking subject according to 64 % of responders. The DSLR camera and the studio lighting demonstrated the youngest looking subject according to 70 % of the responders. The majority of the responders (78 %) chose the combination of DSLR camera and ring light that exhibited the wrinkles the most. We suggest using a ring light to obtain well-lit photographs without loss of detail, with any type of cameras. However, smartphones must be avoided if standard pictures are desired. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Lattice QCD Calculation of Hadronic Light-by-Light Scattering.

PubMed

Green, Jeremy; Gryniuk, Oleksii; von Hippel, Georg; Meyer, Harvey B; Pascalutsa, Vladimir

2015-11-27

We perform a lattice QCD calculation of the hadronic light-by-light scattering amplitude in a broad kinematical range. At forward kinematics, the results are compared to a phenomenological analysis based on dispersive sum rules for light-by-light scattering. The size of the pion pole contribution is investigated for momenta of typical hadronic size. The presented numerical methods can be used to compute the hadronic light-by-light contribution to the anomalous magnetic moment of the muon. Our calculations are carried out in two-flavor QCD with the pion mass in the range of 270-450 MeV and contain so far only the diagrams with fully connected quark lines.

Dual-Located WHIRLY1 Interacting with LHCA1 Alters Photochemical Activities of Photosystem I and Is Involved in Light Adaptation in Arabidopsis

PubMed Central

Huang, Dongmei; Lin, Wenfang; Deng, Ban

2017-01-01

Plastid-nucleus-located WHIRLY1 protein plays a role in regulating leaf senescence and is believed to associate with the increase of reactive oxygen species delivered from redox state of the photosynthetic electron transport chain. In order to make sure whether WHIRLY1 plays a role in photosynthesis, in this study, the performances of photosynthesis were detected in Arabidopsis whirly1 knockout (kowhy1) and plastid localized WHIRLY1 overexpression (oepWHY1) plants. Loss of WHIRLY1 leads to a higher photochemical quantum yield of photosystem I Y(I) and electron transport rate (ETR) and a lower non-photochemical quenching (NPQ) involved in the thermal dissipation of excitation energy of chlorophyll fluorescence than the wild type. Further analyses showed that WHIRLY1 interacts with Light-harvesting protein complex I (LHCA1) and affects the expression of genes encoding photosystem I (PSI) and light harvest complexes (LHCI). Moreover, loss of WHIRLY1 decreases chloroplast NAD(P)H dehydrogenase-like complex (NDH) activity and the accumulation of NDH supercomplex. Several genes encoding the PSI-NDH complexes are also up-regulated in kowhy1 and the whirly1whirly3 double mutant (ko1/3) but steady in oepWHY1 plants. However, under high light conditions (800 μmol m−2 s−1), both kowhy1 and ko1/3 plants show lower ETR than wild-type which are contrary to that under normal light condition. Moreover, the expression of several PSI-NDH encoding genes and ERF109 which is related to jasmonate (JA) response varied in kowhy1 under different light conditions. These results indicate that WHIRLY1 is involved in the alteration of ETR by affecting the activities of PSI and supercomplex formation of PSI with LHCI or NDH and may acting as a communicator between the plastids and the nucleus. PMID:29112140

Outdoor Lighting Ordinances

NASA Astrophysics Data System (ADS)

Davis, S.

2004-05-01

A principal means to prevent poor exterior lighting practices is a lighting control ordinance. It is an enforceable legal restriction on specific lighting practices that are deemed unacceptable by the government body having jurisdiction. Outdoor lighting codes have proven to be effective at reducing polluting and trespassing light. A well written exterior lighting code will permit all forms of necessary illumination at reasonable intensities, but will demand shielding and other measures to prevent trespass and light pollution. A good code will also apply to all forms of outdoor lighting, including streets, highways, and exterior signs, as well as the lighting on dwellings, commercial and industrial buildings and building sites. A good code can make exceptions for special uses, provided it complies with an effective standard. The IDA Model Lighting Ordinance is a response to these requests. It is intended as an aid to communities that are seeking to take control of their outdoor lighting, to "take back the night" that is being lost to careless and excessive use of night lighting.

Signal lights - designed light for rear lamps and new upcoming technologies: innovations in automotive lighting

NASA Astrophysics Data System (ADS)

Mügge, Martin; Hohmann, Carsten

2016-04-01

Signal functions have to fulfill statutory regulations such as ECE or FMVSS108 to provide a clear signal to other road users and satisfy the same standard definitions of lighting parameters. However, as rear combination lamps are very different from one another, and these days are an increasingly powerful design element of cars, automotive manufacturers want an innovative, superior, and contrasting design. Daytime appearances with a new and unusual look and nighttime appearances with unexpected illumination are strong drivers for developing amazing innovative signal functions. The combination of LED technology and different forms of light-guiding optics, new interpretations of common optical systems to develop various styling options, the use of new materials and components for lighting effects, the introduction of OLED technology on the automotive market, and amazing new optical systems, using diffractive or holographic optics in future rear lamps, are paving the way for further, exciting design possibilities. The challenge of new signal functions is to take these possibilities and to develop the appearance and illumination effects the designer wants to reinforce the image of the car manufacturer and to fit harmoniously into the vehicle design. Lighting systems with a three-dimensional design and appearance when unlit and lit, amazing 3D effects, and surprising lighting scenarios will gain in importance. But the signal lights on cars will, in the future, be not only lighting functions in rear lamps; new functions and stylistic illuminations for coming/leaving-home scenarios will support and complete the car's overall lighting appearance. This paper describes current lighting systems realizing the styling requirements and future lighting systems offering new design possibilities and developing further stylistic, visual effects and improved technologies.

Studying Light Color using White LED Lighting

NASA Astrophysics Data System (ADS)

Yamagishi, Misako; Yamaba, Kazuo; Nagata, Manori; Kubo, Chiho; Nokura, Kunihiro

Recently, white Light Emitting Diodes (LEDs) are receiving attention worldwide as new lighting devices. This study examined effects of a lighting application on performance using white LEDs. The light color—the correlated color temperature (CCT) —was assessed. It affected to psychological states and physiological conditions. Three CCT conditions were respectively set for the experiment: 2500 K, 5000 K, and 8200 K. In all, 20 younger subjects (20-30 years old), 15 middle-aged to elderly subjects (45-60 years old) and 12 elderly subjects (over 65 years-old) participated. They were presented a Numerical Verification (NV) task for performance measurement. The psychological states on performance were evaluated using the lighting assessment questionnaire. The physiological conditions were recorded using an electrocardiograph. Results show that the effects of CCT differ among age groups. Especially, the performance of younger subjects might differ from CCT conditions; elderly subjects are affected by CCT condition because of their visual acuity or response to contrast of objects.

LIGHT-ing Up Prostate Cancer for Immunotherapy

DTIC Science & Technology

2016-10-01

Award Number: W81XWH-15-1-0491 TITLE: LIGHT -ing up prostate cancer for immunotherapy PRINCIPAL INVESTIGATOR: W. Martin Kast, Ph.D...FORM TO THE ABOVE ADDRESS. 1. REPORT DATE October 2016 2. REPORT TYPE Annual 3. DATES COVERED 4. TITLE AND SUBTITLE LIGHT -ing up prostate cancer...expression of LIGHT molecules within the tumor milieu counteracts cancer immune-evasion mechanisms and instigates activation and migration of T-cells

Light Sources and Lighting Circuits

NASA Astrophysics Data System (ADS)

Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

According to the Machinery Statistics of the Ministry of Economy, Trade and Industry, the production of incandescent lamps in Japan in 2007 was 990 million units (90.0% of the previous year's total), in which the production of incandescent lamps for general lighting was 110 million units (90.0% of the previous year's total) and of tungsten-halogen lamps was 44 million units (96.6% of the previous year's total). The production of fluorescent lamps was 927 million units (93.9% of the previous year's total), in which general fluorescent lamps, excluding those for LCD back lighting, was 320 million units (87.2% of the previous year's total). Also, the production of HID lamps was 10 million units (101.5% of the previous year's total). On the other hand, when the numbers of sales are compared with the sales of the previous year, incandescent lamps for general use was 99.8%, tungsten-halogen lamps was 96.9%, fluorescent lamps was 95.9%, and HID lamps was 98.9%. Self-ballasted fluorescent lamps alone showed an increase in sales as strong as 29 million units, or 121.7% of the previous year's sales. It is considered that the switchover of incandescent lamps to HID lamps was promoted for energy conservation and carbon dioxide reduction with the problem of global warming in the background. In regard to exhibitions, Lighting Fair 2007 was held in Tokyo in March, and LIGHTFAIR INTERNATIONAL 2007 was held in New York in May. Regarding academic conferences, LS:11 (the 11th International Symposium on the Science & Technology of Light Sources) was held in Shanghai in May, and the First International Conference on White LEDs and Solid State Lighting was held in Tokyo in November. Both conferences suggested that there are strong needs and concerns now about energy conservation, saving natural resources, and restrictions of hazardous materials. In regard to incandescent lamps, the development of products aiming at higher efficacy, electric power savings, and longer life was advanced by

Light sensors for objective light measurement in ambulatory polysomnography.

PubMed

Schembri, Rachel; Spong, Jo; Peters, Allison; Rochford, Peter; Wilksch, Philip; O'Donoghue, Fergal J; Greenwood, Kenneth M; Barnes, Maree; Kennedy, Gerard A; Berlowitz, David J

2017-01-01

Ambulatory polysomnography (PSG) does not commonly include an objective measure of light to determine the time of lights off (Loff), and thus cannot be used to calculate important indices such as sleep onset latency and sleep efficiency. This study examined the technical specifications and appropriateness of a prototype light sensor (LS) for use in ambulatory Compumedics Somte PSG.Two studies were conducted. The first examined the light measurement characteristics of the LS when used with a portable PSG device, specifically recording trace range, linearity, sensitivity, and stability. This involved the LS being exposed to varying incandescent and fluorescent light levels in a light controlled room. Secondly, the LS was trialled in 24 home and 12 hospital ambulatory PSGs to investigate whether light levels in home and hospital settings were within the recording range of the LS, and to quantify the typical light intensity reduction at the time of Loff. A preliminary exploration of clinical utility was also conducted. Linearity between LS voltage and lux was demonstrated, and the LS trace was stable over 14 hours of recording. The observed maximum voltage output of the LS/PSG device was 250 mV, corresponding to a maximum recording range of 350 lux and 523 lux for incandescent and fluorescent light respectively. At the time of Loff, light levels were within the recording range of the LS, and on average dropped by 72 lux (9-245) in the home and 76 lux (4-348) in the hospital setting. Results suggest that clinical utility was greatest in hospital settings where patients are less mobile. The LS was a simple and effective objective marker of light level in portable PSG, which can be used to identify Loff in ambulatory PSG. This allows measurement of additional sleep indices and support with clinical decisions.

Luminescence- and nanoparticle-mediated increase of light absorption by photoreceptor cells: Converting UV light to visible light.

PubMed

Li, Lei; Sahi, Sunil K; Peng, Mingying; Lee, Eric B; Ma, Lun; Wojtowicz, Jennifer L; Malin, John H; Chen, Wei

2016-02-10

We developed new optic devices - singly-doped luminescence glasses and nanoparticle-coated lenses that convert UV light to visible light - for improvement of visual system functions. Tb(3+) or Eu(3+) singly-doped borate glasses or CdS-quantum dot (CdS-QD) coated lenses efficiently convert UV light to 542 nm or 613 nm wavelength narrow-band green or red light, or wide-spectrum white light, and thereby provide extra visible light to the eye. In zebrafish (wild-type larvae and adult control animals, retinal degeneration mutants, and light-induced photoreceptor cell degeneration models), the use of Tb(3+) or Eu(3+) doped luminescence glass or CdS-QD coated glass lenses provide additional visible light to the rod and cone photoreceptor cells, and thereby improve the visual system functions. The data provide proof-of-concept for the future development of optic devices for improvement of visual system functions in patients who suffer from photoreceptor cell degeneration or related retinal diseases.

Light Source

NASA Technical Reports Server (NTRS)

1993-01-01

Research on food growth for long duration spacecraft has resulted in a light source for growing plants indoors known as Qbeam, a solid state light source consisting of a control unit and lamp. The light source, manufactured by Quantum Devices, Inc., is not very hot, although it generates high intensity radiation. When Ron Ignatius, an industrial partner of WCSAR, realized that terrestrial plant research lighting was not energy efficient enough for space use, he and WCSAR began to experiment with light emitting diodes. A line of LED products was developed, and QDI was formed to market the technology. An LED-based cancer treatment device is currently under development.

Complex Light

NASA Astrophysics Data System (ADS)

Secor, Jeff; Alfano, Robert; Ashrafi, Solyman

2017-01-01

The emerging field of complex light-the study and application of custom light beams with tailored intensity, polarization or phase-is a focal point for fundamental breakthroughs in optical science. As this review will show, those advances in fundamental understanding, coupled with the latest developments in complex light generation, are translating into a range of diverse and cross-disciplinary applications that span microscopy, high-data-rate communications, optical trapping and quantum optics. We can expect more twists along the way, too, as researchers seek to manipulate and control the propagation speed of complex light beams, while others push the more exotic possibilities afforded by complex light in quantum-entanglement experiments.

Light Reflector

NASA Astrophysics Data System (ADS)

1988-01-01

Ultra Sales, Inc.'s fluorescent lighting fixture gets a boost in reflectivity through installation of Lightdriver, a thin tough thermoplastic film plated with aluminum, capable of reflecting 95 percent of visible light striking it. Lightdriver increases brightness without adding bulbs, and allows energy savings by removing some bulbs because the mirrorlike surface cuts light loss generally occasioned by conventional low reflectivity white painted surface above the bulbs in many fluorescent fixtures. Forty-five percent reduction in lighting electricity is attainable.

European network for Health Technology Assessment Joint Action (EUnetHTA JA): a process evaluation performed by questionnaires and documentary analysis.

PubMed

Woodford Guegan, Eleanor; Cook, Andrew

2014-06-01

The European network for Health Technology Assessment Joint Action (EUnetHTA JA) project's overarching objective was to 'establish an effective and sustainable HTA [Health technology assessment] collaboration in Europe that brings added value at the regional, national and European level'. Specific objectives were to develop a strategy and business model for sustainable European collaboration on HTA, develop HTA tools and methods and promote good practice in HTA methods and processes. We describe activities performed on behalf of the National Institute for Health Research HTA programme; evaluating the project processes and developing a data set for a registry of planned clinical studies of relevance to public funders. Annual self-completion online questionnaires were sent to project participants and external stakeholders to identify their views about the project processes. Documentary review was undertaken at the project end on the final technical reports from the work packages to examine whether or not their deliverables had been achieved. The project's impact was assessed by whether or not the deliverables were produced, the objectives met and additional 'added value' generated. The project's effectiveness was evaluated by its processes, communication, administration, workings of individual work packages and involvement of external stakeholders. A two-stage Delphi exercise was undertaken to identify the data elements that should be included in a registry of planned clinical studies of relevance to public funders. The data set was validated by an efficacy testing exercise. High response rates were achieved for the questionnaires sent to project participants and this was attributed to the evidence-based strategy implemented. Response rates to questionnaires sent to external stakeholders were disappointingly lower. Most of the high-level objectives were achieved, although applying the developed tools in practice will be implemented in the European network for Health

European network for Health Technology Assessment Joint Action (EUnetHTA JA): a process evaluation performed by questionnaires and documentary analysis.

PubMed Central

Woodford Guegan, Eleanor; Cook, Andrew

2014-01-01

BACKGROUND The European network for Health Technology Assessment Joint Action (EUnetHTA JA) project's overarching objective was to 'establish an effective and sustainable HTA [Health technology assessment] collaboration in Europe that brings added value at the regional, national and European level'. Specific objectives were to develop a strategy and business model for sustainable European collaboration on HTA, develop HTA tools and methods and promote good practice in HTA methods and processes. We describe activities performed on behalf of the National Institute for Health Research HTA programme; evaluating the project processes and developing a data set for a registry of planned clinical studies of relevance to public funders. METHODS Annual self-completion online questionnaires were sent to project participants and external stakeholders to identify their views about the project processes. Documentary review was undertaken at the project end on the final technical reports from the work packages to examine whether or not their deliverables had been achieved. The project's impact was assessed by whether or not the deliverables were produced, the objectives met and additional 'added value' generated. The project's effectiveness was evaluated by its processes, communication, administration, workings of individual work packages and involvement of external stakeholders. A two-stage Delphi exercise was undertaken to identify the data elements that should be included in a registry of planned clinical studies of relevance to public funders. The data set was validated by an efficacy testing exercise. RESULTS AND DISCUSSION High response rates were achieved for the questionnaires sent to project participants and this was attributed to the evidence-based strategy implemented. Response rates to questionnaires sent to external stakeholders were disappointingly lower. Most of the high-level objectives were achieved, although applying the developed tools in practice will be

Effects of supplementary lighting by natural light for growth of Brassica chinensis

NASA Astrophysics Data System (ADS)

Yeh, Shih-Chuan; Lee, Hui-Ping; Kao, Shih-Tse; Lu, Ju-Lin

2016-04-01

This paper present a model of cultivated chamber with supplementary natural colour light. We investigate the effects of supplementary natural red light and natural blue light on growth of Brassica chinensis under natural white light illumination. After 4 weeks of supplementary colour light treatment, the experiment results shown that the weight of fresh leaf were not affected by supplementary natural blue light. However, those Brassica chinensis were cultivated in the chambers with supplementary natural red light obtained a significant increasing of fresh weight of leaf under both white light illuminate models. The combination of natural white light with supplementary natural red light illumination will be benefits in growth for cultivation and energy saving.

Supersymmetry across the light and heavy-light hadronic spectrum. II.

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

Dosch, Hans Gunter; de Téramond, Guy F.; Brodsky, Stanley J.

We extend our analysis of the implications of hadronic supersymmetry for heavy-light hadrons in light-front holographic QCD. Although conformal symmetry is strongly broken by the heavy quark mass, supersymmetry and the holographic embedding of semiclassical light-front dynamics derived from five-dimensional anti-de Sitter space nevertheless determine the form of the confining potential in the light-front Hamiltonian to be harmonic. The resulting light-front bound-state equations lead to a heavy-light Regge-like spectrum for both mesons and baryons. The confinement hadron mass scale and their Regge slopes depend, however, on the mass of the heavy quark in the meson or baryon as expected frommore » heavy quark effective theory. Furthermore, this procedure reproduces the observed spectra of heavy-light hadrons with good precision and makes predictions for yet unobserved states.« less

Supersymmetry across the light and heavy-light hadronic spectrum. II.

DOE PAGES

Dosch, Hans Gunter; de Téramond, Guy F.; Brodsky, Stanley J.

2017-02-15

We extend our analysis of the implications of hadronic supersymmetry for heavy-light hadrons in light-front holographic QCD. Although conformal symmetry is strongly broken by the heavy quark mass, supersymmetry and the holographic embedding of semiclassical light-front dynamics derived from five-dimensional anti-de Sitter space nevertheless determine the form of the confining potential in the light-front Hamiltonian to be harmonic. The resulting light-front bound-state equations lead to a heavy-light Regge-like spectrum for both mesons and baryons. The confinement hadron mass scale and their Regge slopes depend, however, on the mass of the heavy quark in the meson or baryon as expected frommore » heavy quark effective theory. Furthermore, this procedure reproduces the observed spectra of heavy-light hadrons with good precision and makes predictions for yet unobserved states.« less

Mobile lighting apparatus

DOEpatents

Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

2013-05-14

A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

Multilayer white lighting polymer light-emitting diodes

NASA Astrophysics Data System (ADS)

Gong, Xiong; Wang, Shu; Heeger, Alan J.

2006-08-01

Organic and polymer light-emitting diodes (OLEDs/PLEDs) that emit white light are of interest and potential importance for use in active matrix displays (with color filters) and because they might eventually be used for solid-state lighting. In such applications, large-area devices and low-cost of manufacturing will be major issues. We demonstrated that high performance multilayer white emitting PLEDs can be fabricated by using a blend of luminescent semiconducting polymers and organometallic complexes as the emission layer, and water-soluble (or ethanol-soluble) polymers/small molecules (for example, PVK-SO 3Li) as the hole injection/transport layer (HIL/HTL) and water-soluble (or ethanol-soluble) polymers/small molecules (for example, t-Bu-PBD-SO 3Na) as the electron injection/transport layer (EIL/HTL). Each layer is spin-cast sequentially from solutions. Illumination quality light is obtained with stable Commission Internationale d'Eclairage coordinates, stable color temperatures, and stable high color rendering indices, all close to those of "pure" white. The multilayer white-emitting PLEDs exhibit luminous efficiency of 21 cd/A, power efficiency of 6 lm/W at a current density of 23 mA/cm2 with luminance of 5.5 x 10 4 cd/m2 at 16 V. By using water-soluble (ethanol-soluble) polymers/small molecules as HIL/HTL and polymers/small molecules as EIL/ETL, the interfacial mixing problem is solved (the emissive polymer layer is soluble in organic solvents, but not in water/ ethanol). As a result, this device architecture and process technology can potentially be used for printing large-area multiplayer light sources and for other applications in "plastic" electronics. More important, the promise of producing large areas of high quality white light with low-cost manufacturing technology makes the white multilayer white-emitting PLEDs attractive for the development of solid state light sources.

Bridges, Lights, and Hubris: Examples of Excessive Light Pollution

NASA Astrophysics Data System (ADS)

Upgren, A. R.

2000-12-01

Recently many new lighting projects have been planned, frequently for the purpose of bringing attention to a tower or bridge, with the intent of promoting it as a tourist attraction. Examples of this form of light pollution are illustrated here. Many proceed with plans to mount new floodlights pointed upward with most of the light shining directly up into the sky. At least three of the more excessive among them have been tabled or aborted upon objections by members of the International Dark-Sky Association and other environmental groups. Opposition to the most ill-conceived of these plans centers on waste of money and energy, excessive fatalities among migratory birds, damage to the aesthetic beauty and study of the night sky, and (near seacoasts) damage to the nesting and hatching of sea turtles. Constructive opposition to lighting excess and glare may include the substitution of tracer lights, such as the ones that adorn the great suspension bridges of New York and San Francisco. Tracer lights using full-cutoff shielding outline a structure much as lights on a Christmas tree delineate its shape, but floodlights in the mix render a washed-out effect similar to a Christmas tree in broad daylight. The AAS Committee on Light Pollution, Radio Interference, and Space Debris encourages a greater role for the Society in coordinating opposition to such projects, which is too often local and inexperienced.

Flexible liquid core light guide with focusing and light shaping attachments

DOEpatents

Kross, B.J.; Majewski, S.; Zorn, C.J.; Majewski, L.A.

1997-11-04

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. 12 figs.

[Progress of light extraction enhancement in organic light-emitting devices].

PubMed

Liu, Mo; Li, Tong; Wang, Yan; Zhang, Tian-Yu; Xie, Wen-Fa

2011-04-01

Organic light emitting devices (OLEDs) have been used in flat-panel displays and lighting with a near-30-year development. OLEDs possess many advantages, such as full solid device, fast response, flexible display, and so on. As the application of phosphorescence material, the internal quantum efficiency of OLED has almost reached 100%, but its external quantum efficiency is still not very high due to the low light extraction efficiency. In this review the authors summarizes recent advances in light extraction techniques that have been developed to enhance the light extraction efficiency of OLEDs.

GA3 and other signal regulators (MeJA and IAA) improve xanthumin biosynthesis in different manners in Xanthium strumarium L.

PubMed

Li, Changfu; Chen, Fangfang; Zhang, Yansheng

2014-08-25

Xanthanolides from Xanthium strumarium L. exhibit various pharmacological activities and these compounds are mainly produced in the glandular trichomes of aerial plant parts. The regulation of xanthanolide biosynthesis has never been reported in the literature. In this study, the effects of phytohormonal stimulation on xanthumin (a xanthanolide compound) biosynthesis, glandular trichomes and germacrene A synthase (GAS) gene expression in X. strumarium L. young leaves were investigated. The exogenous applications of methyl jasmonate (MeJA), indole-3-acetic acid (IAA), and gibberrellin A3 (GA3) at appropriate concentrations were all found to improve xanthumin biosynthesis, but in different ways. It was suggested that a higher gland density stimulated by MeJA (400 µM) or IAA (200 µM) treatment caused at least in part an improvement in xanthumin production, whereas GA3 (10 µM) led to an improvement by up-regulating xanthumin biosynthetic genes within gland cells, not by forming more glandular trichomes. Compared to the plants before the flowering stage, plants that had initiated flowering showed enhanced xanthumin biosynthesis, but no higher gland density, an effect was similar to that caused by exogenous GA3 treatment.

Light emission mechanism of mixed host organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Song, Wook; Lee, Jun Yeob

2015-03-01

Light emission mechanism of organic light-emitting diodes with a mixed host emitting layer was studied using an exciplex type mixed host and an exciplex free mixed host. Monitoring of the current density and luminance of the two type mixed host devices revealed that the light emission process of the exciplex type mixed host was dominated by energy transfer, while the light emission of the exciplex free mixed host was controlled by charge trapping. Mixed host composition was also critical to the light emission mechanism, and the contribution of the energy transfer process was maximized at 50:50 mixed host composition. Therefore, it was possible to manage the light emission process of the mixed host devices by managing the mixed host composition.

A lighting metric for quantitative evaluation of accent lighting systems

NASA Astrophysics Data System (ADS)

Acholo, Cyril O.; Connor, Kenneth A.; Radke, Richard J.

2014-09-01

Accent lighting is critical for artwork and sculpture lighting in museums, and subject lighting for stage, Film and television. The research problem of designing effective lighting in such settings has been revived recently with the rise of light-emitting-diode-based solid state lighting. In this work, we propose an easy-to-apply quantitative measure of the scene's visual quality as perceived by human viewers. We consider a well-accent-lit scene as one which maximizes the information about the scene (in an information-theoretic sense) available to the user. We propose a metric based on the entropy of the distribution of colors, which are extracted from an image of the scene from the viewer's perspective. We demonstrate that optimizing the metric as a function of illumination configuration (i.e., position, orientation, and spectral composition) results in natural, pleasing accent lighting. We use a photorealistic simulation tool to validate the functionality of our proposed approach, showing its successful application to two- and three-dimensional scenes.

Printing method for organic light emitting device lighting

NASA Astrophysics Data System (ADS)

Ki, Hyun Chul; Kim, Seon Hoon; Kim, Doo-Gun; Kim, Tae-Un; Kim, Snag-Gi; Hong, Kyung-Jin; So, Soon-Yeol

2013-03-01

Organic Light Emitting Device (OLED) has a characteristic to change the electric energy into the light when the electric field is applied to the organic material. OLED is currently employed as a light source for the lighting tools because research has extensively progressed in the improvement of luminance, efficiency, and life time. OLED is widely used in the plate display device because of a simple manufacture process and high emitting efficiency. But most of OLED lighting projects were used the vacuum evaporator (thermal evaporator) with low molecular. Although printing method has lower efficiency and life time of OLED than vacuum evaporator method, projects of printing OLED actively are progressed because was possible to combine with flexible substrate and printing technology. Printing technology is ink-jet, screen printing and slot coating. This printing method allows for low cost and mass production techniques and large substrates. In this research, we have proposed inkjet printing for organic light-emitting devices has the dominant method of thick film deposition because of its low cost and simple processing. In this research, the fabrication of the passive matrix OLED is achieved by inkjet printing, using a polymer phosphorescent ink. We are measured optical and electrical characteristics of OLED.

Assessment of iodine nutritional status in the general population in the province of Jaén.

PubMed

Olmedo Carrillo, Pablo; García Fuentes, Eduardo; Gutiérrez Alcántara, Carmen; Serrano Quero, Manuel; Moreno Martínez, Macarena; Ureña Fernández, Tomás; Santiago Fernández, Piedad

2015-10-01

Iodine deficiency affecting both pregnant women and schoolchildren has been reported in Jaén. Iodine deficiency is one of the leading causes of thyroid dysfunction and goiter, and adequate iodine prophylaxis with iodized salt, milk, and dairy products, or iodine supplementation have been shown to significantly improve iodine status in pregnancy. The purpose of this study was to assess iodine nutritional status in the general population of a iodine-deficient area with no previous institutional campaigns of iodine prophylaxis. A descriptive, cross-sectional study. Urinary iodine levels were measured in subjects from the Jaén healthcare district. The data were stratified by sex and age groups, and a survey was conducted on iodized salt consumption. Median and mean urinary iodine levels were 110.59 mcg/L and 130.11 mcg/L respectively. Urinary iodine levels were significantly higher in schoolchildren as compared to other age groups (161.52μg/L vs 109.33μg/L in subjects older than 65 years). Forty-three percent of the population had urinary iodine levels less than 100μg/L, and 68% of women of childbearing age had levels less than 150μg/L. Iodine nutritional status appears to be adequate, but the proportion of the population with urinary iodine levels less than 100μg/L is still very high, and iodized salt consumption is much less common than recommended by the WHO. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

SCHOOL LIGHTING

ERIC Educational Resources Information Center

1965

SEVERAL ARTICLES ON SCHOOL LIGHTING ARE CONTAINED IN THIS JOURNAL. THE TITLES AND AUTHORS INCLUDED ARE AS FOLLOWS--(1) "TODAY'S CONCEPTS IN SCHOOL LIGHTING" BY CHARLES D. GIBSON, (2) "CHALLENGE OF TOMMORROW'S LIGHTING" BY S.K. GUTH AND E.H. WITTE, (3) "PEEK PREVIEW OF THE WINDOWLESS SCHOOL" BY JAMES J. MORISSEAU, (4) "MAINTENANCE BEGINS BEFORE…

Matrix light and pixel light: optical system architecture and requirements to the light source

NASA Astrophysics Data System (ADS)

Spinger, Benno; Timinger, Andreas L.

2015-09-01

Modern Automotive headlamps enable improved functionality for more driving comfort and safety. Matrix or Pixel light headlamps are not restricted to either pure low beam functionality or pure high beam. Light in direction of oncoming traffic is selectively switched of, potential hazard can be marked via an isolated beam and the illumination on the road can even follow a bend. The optical architectures that enable these advanced functionalities are diverse. Electromechanical shutters and lens units moved by electric motors were the first ways to realize these systems. Switching multiple LED light sources is a more elegant and mechanically robust solution. While many basic functionalities can already be realized with a limited number of LEDs, an increasing number of pixels will lead to more driving comfort and better visibility. The required optical system needs not only to generate a desired beam distribution with a high angular dynamic, but also needs to guarantee minimal stray light and cross talk between the different pixels. The direct projection of the LED array via a lens is a simple but not very efficient optical system. We discuss different optical elements for pre-collimating the light with minimal cross talk and improved contrast between neighboring pixels. Depending on the selected optical system, we derive the basic light source requirements: luminance, surface area, contrast, flux and color homogeneity.

Light collection optics for measuring flux and spectrum from light-emitting devices

DOEpatents

McCord, Mark A.; DiRegolo, Joseph A.; Gluszczak, Michael R.

2016-05-24

Systems and methods for accurately measuring the luminous flux and color (spectra) from light-emitting devices are disclosed. An integrating sphere may be utilized to directly receive a first portion of light emitted by a light-emitting device through an opening defined on the integrating sphere. A light collector may be utilized to collect a second portion of light emitted by the light-emitting device and direct the second portion of light into the integrating sphere through the opening defined on the integrating sphere. A spectrometer may be utilized to measure at least one property of the first portion and the second portion of light received by the integrating sphere.

PFP Emergency Lighting Study

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

BUSCH, M.S.

2000-02-02

NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergencymore » Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently or for significant lengths of time will need one or two Backup lights to provide general illumination of the egress points. (2) Complexity of the egress routes. Office spaces with a standard hallway/room configuration will not require Backup Lights while a large room with several subdivisions or irregularly placed rooms, doors, and equipment will require Backup Lights to make egress safer. (3) Reasonable balance between the safety benefits of additional lighting and the man-hours/exposure required for periodic light maintenance. In some plant areas such as building 236-Z, the additional maintenance time and risk of contamination do not warrant having Backup Lights installed in

Nanofocusing of structured light for quadrupolar light-matter interactions.

PubMed

Sakai, Kyosuke; Yamamoto, Takeaki; Sasaki, Keiji

2018-05-17

The spatial structure of an electromagnetic field can determine the characteristics of light-matter interactions. A strong gradient of light in the near field can excite dipole-forbidden atomic transitions, e.g., electric quadrupole transitions, which are rarely observed under plane-wave far-field illumination. Structured light with a higher-order orbital angular momentum state may also modulate the selection rules in which an atom can absorb two quanta of angular momentum: one from the spin and another from the spatial structure of the beam. Here, we numerically demonstrate a strong focusing of structured light with a higher-order orbital angular momentum state in the near field. A quadrupole field was confined within a gap region of several tens of nanometres in a plasmonic tetramer structure. A plasmonic crystal surrounding the tetramer structure provides a robust antenna effect, where the incident structured light can be strongly coupled to the quadrupole field in the gap region with a larger alignment tolerance. The proposed system is expected to provide a platform for light-matter interactions with strong multipolar effects.

Evaluation of light-emitting diode beacon light fixtures : final report.

DOT National Transportation Integrated Search

2009-12-01

Rotating beacons containing filament light sources have long been used on highway maintenance trucks : to indicate the presence of the truck to other drivers. Because of advances in light-emitting diode (LED) : technologies, flashing lights containin...

High Intensity Lights

NASA Technical Reports Server (NTRS)

1983-01-01

Xenon arc lamps developed during the Apollo program by Streamlight, Inc. are the basis for commercial flashlights and emergency handlights. These are some of the brightest portable lights made. They throw a light some 50 times brighter than automobile high beams and are primarily used by police and military. The light penetrates fog and smoke and returns less back-scatter light. They are operated on portable power packs as boat and auto batteries. An infrared model produces totally invisible light for covert surveillance.

10. LIGHT TOWER, VIEW NORTHEAST FROM LIGHT PLATFORM, SOUTHWEST SIDE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. LIGHT TOWER, VIEW NORTHEAST FROM LIGHT PLATFORM, SOUTHWEST SIDE OF BOAT HOUSE AND KEEPER'S HOUSE, WITH DETAIL OF RAILING IN FOREGROUND - Grindle Point Light Station, Western end of Ferry Road on Grindle Point, Islesboro, Waldo County, ME

2. Southern Light Tower and Northern Light Tower, view north, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Southern Light Tower and Northern Light Tower, view north, south sides - Kennebec River Light Station, South side of Doubling Point Road, off State Highway 127, 1.8 miles south of U.S. Route 1, Arrowsic, Sagadahoc County, ME

Light metal production

DOEpatents

Fan, Qinbai

2016-04-19

An electrochemical process for the production of light metals, particularly aluminum. Such a process involves contacting a light metal source material with an inorganic acid to form a solution containing the light metal ions in high concentration. The solution is fed to an electrochemical reactor assembly having an anode side containing an anode and a cathode side containing a cathode, with anode side and the cathode side separated by a bipolar membrane, with the solution being fed to the anode side. Light metal ions are electrochemically transferred through the bipolar membrane to the cathode side. The process further involves reducing the light metal ions to light metal powder. An associated processing system is also provided.

Compact light-emitting diode lighting ring for video-assisted thoracic surgery.

PubMed

Lu, Ming-Kuan; Chang, Feng-Chen; Wang, Wen-Zhe; Hsieh, Chih-Cheng; Kao, Fu-Jen

2014-01-01

In this work, a foldable ring-shaped light-emitting diode (LED) lighting assembly, designed to attach to a rubber wound retractor, is realized and tested through porcine animal experiments. Enabled by the small size and the high efficiency of LED chips, the lighting assembly is compact, flexible, and disposable while providing direct and high brightness lighting for more uniform background illumination in video-assisted thoracic surgery (VATS). When compared with a conventional fiber bundle coupled light source that is usually used in laparoscopy and endoscopy, the much broader solid angle of illumination enabled by the LED assembly allows greatly improved background lighting and imaging quality in VATS.

Lighting in Schools.

ERIC Educational Resources Information Center

Department of Education and Science, London (England).

The application of good lighting principles to school design is discussed. Part 1 of the study is concerned with the general principles of light and vision as they affect lighting in schools. Parts 2 and 3 deal with the application of these principles to daylighting and artificial lighting. Part 4 discusses the circumstances in which the…

RNA sequencing on Amomum villosum Lour. induced by MeJA identifies the genes of WRKY and terpene synthases involved in terpene biosynthesis.

PubMed

He, Xueying; Wang, Huan; Yang, Jinfen; Deng, Ke; Wang, Teng

2018-02-01

Amomum villosum Lour. is an important Chinese medicinal plant that has diverse medicinal functions, and mainly contains volatile terpenes. This study aims to explore the WRKY transcription factors (TFs) and terpene synthase (TPS) unigenes that might be involved in terpene biosynthesis in A. villosum, and thus providing some new information on the regulation of terpenes in plants. RNA sequencing of A. villosum induced by methyl jasmonate (MeJA) revealed that the WRKY family was the second largest TF family in the transcriptome. Thirty-six complete WRKY domain sequences were expressed in response to MeJA. Further, six WRKY unigenes were highly correlated with eight deduced TPS unigenes. Ultimately, we combined the terpene abundance with the expression of candidate WRKY TFs and TPS unigenes to presume a possible model wherein AvWRKY61, AvWRKY28, and AvWRKY40 might coordinately trans-activate the AvNeoD promoter. We propose an approach to further investigate TF unigenes that might be involved in terpenoid biosynthesis, and identified four unigenes for further analyses.

Light quality and efficiency of consumer grade solid state lighting products

NASA Astrophysics Data System (ADS)

Dam-Hansen, Carsten; Corell, Dennis Dan; Thorseth, Anders; Poulsen, Peter Behrensdorff

2013-03-01

The rapid development in flux and efficiency of Light Emitting Diodes (LED) has resulted in a flooding of the lighting market with Solid State Lighting (SSL) products. Many traditional light sources can advantageously be replaced by SSL products. There are, however, large variations in the quality of these products, and some are not better than the ones they are supposed to replace. A lack of quality demands and standards makes it difficult for consumers to get an overview of the SSL products. Here the results of a two year study investigating SSL products on the Danish market are presented. Focus has been on SSL products for replacement of incandescent lamps and halogen spotlights. The warm white light and good color rendering properties of these traditional light sources are a must for lighting in Denmark and the Nordic countries. 266 SSL replacement lamps have been tested for efficiency and light quality with respect to correlated color temperature and color rendering properties. This shows a trade-off between high color rendering warm white light and energy efficiency. The lumen and color maintenance over time has been investigated and results for products running over 11000 h will be presented. A new internet based SSL product selection tool will be shown. Here the products can be compared on efficiency, light quality parameters, thus providing a better basis for the selection of SSL products for consumers.

Light-adjustable lens.

PubMed Central

Schwartz, Daniel M

2003-01-01

PURPOSE: First, to determine whether a silicone light-adjustable intraocular lens (IOL) can be fabricated and adjusted precisely with a light delivery device (LDD). Second, to determine the biocompatibility of an adjustable IOL and whether the lens can be adjusted precisely in vivo. METHODS: After fabrication of a light-adjustable silicone formulation, IOLs were made and tested in vitro for cytotoxicity, leaching, precision of adjustment, optical quality after adjustment, and mechanical properties. Light-adjustable IOLs were then tested in vivo for biocompatibility and precision of adjustment in a rabbit model. In collaboration with Zeiss-Meditec, a digital LDD was developed and tested to correct for higher-order aberrations in light-adjustable IOLs. RESULTS: The results establish that a biocompatible silicone IOL can be fabricated and adjusted using safe levels of light. There was no evidence of cytotoxicity or leaching. Testing of mechanical properties revealed no significant differences from commercial controls. Implantation of light-adjustable lenses in rabbits demonstrated- excellent biocompatibility after 6 months, comparable to a commercially available IOL. In vivo spherical (hyperopic and myopic) adjustment in rabbits was achieved using an analog light delivery system. The digital light delivery system was tested and achieved correction of higher-order aberrations. CONCLUSION: A silicone light-adjustable IOL and LDD have been developed to enable postoperative, noninvasive adjustment of lens power. The ability to correct higher-order aberrations in these materials has broad potential applicability for optimization of vision in patients undergoing cataract and refractive surgery. PMID:14971588

Flexible, liquid core light guide with focusing and light shaping attachments

DOEpatents

Wojcik, Randolph Frank; Majewski, Stanislaw; Zorn, Carl John; Kross, Brian

1999-01-01

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs.

Flexible, liquid core light guide with focusing and light shaping attachments

DOEpatents

Wojcik, R.F.; Majewski, S.; Zorn, C.J.; Kross, B.

1999-04-20

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs. 19 figs.

Measures of Light in Studies on Light-Driven Plant Plasticity in Artificial Environments

PubMed Central

Niinemets, Ülo; Keenan, Trevor F.

2012-01-01

Within-canopy variation in light results in profound canopy profiles in foliage structural, chemical, and physiological traits. Studies on within-canopy variations in key foliage traits are often conducted in artificial environments, including growth chambers with only artificial light, and greenhouses with and without supplemental light. Canopy patterns in these systems are considered to be representative to outdoor conditions, but in experiments with artificial and supplemental lighting, the intensity of artificial light strongly deceases with the distance from the light source, and natural light intensity in greenhouses is less than outdoors due to limited transmittance of enclosure walls. The implications of such changes in radiation conditions on canopy patterns of foliage traits have not yet been analyzed. We developed model-based methods for retrospective estimation of distance vs. light intensity relationships, for separation of the share of artificial and natural light in experiments with combined light and for estimation of average enclosure transmittance, and estimated daily integrated light at the time of sampling (Qint,C), at foliage formation (Qint,G), and during foliage lifetime (Qint,av). The implications of artificial light environments were analyzed for altogether 25 studies providing information on within-canopy gradients of key foliage traits for 70 species × treatment combinations. Across the studies with artificial light, Qint,G for leaves formed at different heights in the canopy varied from 1.8- to 6.4-fold due to changing the distance between light source and growing plants. In experiments with combined lighting, the share of natural light at the top of the plants varied threefold, and the share of natural light strongly increased with increasing depth in the canopy. Foliage nitrogen content was most strongly associated with Qint,G, but photosynthetic capacity with Qint,C, emphasizing the importance of explicit description of light

Light Pollution at Mount Wilson: Effect of Lighting Technology Changes

NASA Astrophysics Data System (ADS)

Garstang, R. H.

2000-05-01

In an earlier paper (Bull. AAS. 30, 838, 1998; Mem. Soc. Astr. Italia, in press, 2000) I studied the effects of population growth and of smog on the historical growth of light pollution at Mount Wilson. I have now done some very crude calculations to evaluate the effect of changes in lighting technology - the most important change being from incandescent lamps to mercury vapor lamps to high pressure sodium lamps in street lighting. I am greatly indebted to George Eslinger, lately Director of the Bureau of Public Lighting of the City of Los Angeles, for information on the numbers and types of street lights in that City. The ratio of numbers of lamps of different kinds throughout the Los Angeles basin at any given date has been assumed to be the same as in the City. The contributions to the photon output in the B and V photometric bands have been estimated. The calculations show a rate of increase of the V brightness greater than that obtained if lighting changes are neglected. The B brightness shows a maximum during the period when mercury vapor street lighting predominated. I hope to refine my calculations when additional information becomes available.

Light emitting diodes as a plant lighting source

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

Bula, R.J.; Tennessen, D.J.; Morrow, R.C.

1994-12-31

Electroluminescence in solid materials is defined as the generation of light by the passage of an electric current through a body of solid material under an applied electric field. A specific type of electroluminescence, first noted by Lossew in 1923, involves the generation of photons when electrons are passed through a p-n junction of certain solid materials (junction of a n-type semiconductor, an electron donor, and a p-type semiconductor, an electron acceptor). Development efforts to translate these observations into visible light emitting devices, however, was not undertaken until the 1950s. The term, light emitting diode (LEDs), was first used inmore » a report by Wolfe, et al., in 1955. The development of this light emitting semiconductor technology dates back less than 30 years. During this period of time, the LED has evolved from a rare and expensive light generating device to one of the most widely used electronic components. The most popular applications of the LED are as indicators or as optoelectronic switches. However, several recent advances in LED technology have made possible the utilization of LEDs for applications that require a high photon flux, such as for plant lighting in controlled environments. The new generation of LEDs based on a gallium aluminum arsenide (GaAlAS) semiconductor material fabricated as a double heterostructure on a transparent substrate has opened up many new applications for these LEDs.« less

Pro Memoria. Professor Bolesław Jałowy (1906-1943): Mortui viventes obligant - the livings are obligated to the dead.

PubMed

Wincewicz, Andrzej

2016-01-01

Professor Bolesław Jałowy (1906-1943) was a chairman of Department of Histology and Embryology at Faculty of Medicine of King John Casimir University (Polish: Universytet Jana Kazimierza: UJK) in Lvov. He succeeded Professor Władysław Szymonowicz (1869-1939) who held this position for decades. As the most skillful followers of his tutor, Bolesław Jałowy was a great investigator of physiology of human tissue, embryogenesis, histological consequences of female sex hormones on blood clotting action as well as regeneration of nerves in addition to description of silver staining technique for reticulin fibers of skin. He was a hard working person with gentle attitude to such a subtle matter as microscopic structure of human body. However, he happened to live in brutal conditions of nationalistic struggles. His example shows how much a dedicated scientist could do in a very short time as his life was tragically ended with murdering him during World War Two. His story is a great lesson for generations of academic workers how to meet high moral standards with efficient and creative scientific work in evil and destructive, nationalistic climate that occurs usually in wartime.

The photocytotoxicity of different lights on mammalian cells in interior lighting system.

PubMed

Song, Jiayin; Gao, Tingting; Ye, Maole; Bi, Hongtao; Liu, Gang

2012-12-05

In the present paper, two light sources commonly used in interior lighting system: incandescent light and light emitting diode (LED) were chosen to evaluate their influences on three kinds of mammalian cells, together with UVA and UVB, and the mechanism of the photocytotoxicity was investigated in terms of intracellular ROS production, lipid peroxidation, SOD activity and GSH level assays. The results showed that LED and incandescent light both had some photocytotoxicities. In the interior lighting condition (100lx-250lx), the cytotoxicities of LED and incandescent lamp on RF/6A cells (rhesus retinal pigment epithelium cell line) were stronger than that on two fibroblast cell lines, while the cytotoxicity of UVA and UVB on HS68 cells (fibroblast cell line) was highest in the tests. The mechanism analysis revealed that the photocytotoxicities of LED and incandescent lamp were both caused by cell lipid peroxidation. LED and incandescent light could promote the production of ROS, raise lipid peroxidation level and lower the activity of the antioxidant key enzymes in mammalian cells, and finally cause a number of cells death. However, the negative function of LED was significantly smaller than incandescent light and ultraviolet in daily interior lighting condition. And the significantly lower photocytotoxicity of LED might be due to the less existence of ultraviolet. Therefore, LED is an efficient and relative safe light source in interior lighting system, which should be widely used instead of traditional light source. Copyright © 2012 Elsevier B.V. All rights reserved.

Phototropin 1 and dim-blue light modulate the red light de-etiolation response.

PubMed

Wang, Yihai; M Folta, Kevin

2014-01-01

Light signals regulate seedling morphological changes during de-etiolation through the coordinated actions of multiple light-sensing pathways. Previously we have shown that red-light-induced hypocotyl growth inhibition can be reversed by addition of dim blue light through the action of phototropin 1 (phot1). Here we further examine the fluence-rate relationships of this blue light effect in short-term (hours) and long-term (days) hypocotyl growth assays. The red stem-growth inhibition and blue promotion is a low-fluence rate response, and blue light delays or attenuates both the red light and far-red light responses. These de-etiolation responses include blue light reversal of red or far-red induced apical hook opening. This response also requires phot1. Cryptochromes (cry1 and cry2) are activated by higher blue light fluence-rates and override phot1's influence on hypocotyl growth promotion. Exogenous application of auxin transport inhibitor naphthylphthalamic acid abolished the blue light stem growth promotion in both hypocotyl growth and hook opening. Results from the genetic tests of this blue light effect in auxin transporter mutants, as well as phytochrome kinase substrate mutants indicated that aux1 may play a role in blue light reversal of red light response. Together, the phot1-mediated adjustment of phytochrome-regulated photomorphogenic events is most robust in dim blue light conditions and is likely modulated by auxin transport through its transporters.

Phototropin 1 and dim-blue light modulate the red light de-etiolation response

PubMed Central

Wang, Yihai; M Folta, Kevin

2014-01-01

Light signals regulate seedling morphological changes during de-etiolation through the coordinated actions of multiple light-sensing pathways. Previously we have shown that red-light-induced hypocotyl growth inhibition can be reversed by addition of dim blue light through the action of phototropin 1 (phot1). Here we further examine the fluence-rate relationships of this blue light effect in short-term (hours) and long-term (days) hypocotyl growth assays. The red stem-growth inhibition and blue promotion is a low-fluence rate response, and blue light delays or attenuates both the red light and far-red light responses. These de-etiolation responses include blue light reversal of red or far-red induced apical hook opening. This response also requires phot1. Cryptochromes (cry1 and cry2) are activated by higher blue light fluence-rates and override phot1's influence on hypocotyl growth promotion. Exogenous application of auxin transport inhibitor naphthylphthalamic acid abolished the blue light stem growth promotion in both hypocotyl growth and hook opening. Results from the genetic tests of this blue light effect in auxin transporter mutants, as well as phytochrome kinase substrate mutants indicated that aux1 may play a role in blue light reversal of red light response. Together, the phot1-mediated adjustment of phytochrome-regulated photomorphogenic events is most robust in dim blue light conditions and is likely modulated by auxin transport through its transporters. PMID:25482790

Compressive light field imaging

NASA Astrophysics Data System (ADS)

Ashok, Amit; Neifeld, Mark A.

2010-04-01

Light field imagers such as the plenoptic and the integral imagers inherently measure projections of the four dimensional (4D) light field scalar function onto a two dimensional sensor and therefore, suffer from a spatial vs. angular resolution trade-off. Programmable light field imagers, proposed recently, overcome this spatioangular resolution trade-off and allow high-resolution capture of the (4D) light field function with multiple measurements at the cost of a longer exposure time. However, these light field imagers do not exploit the spatio-angular correlations inherent in the light fields of natural scenes and thus result in photon-inefficient measurements. Here, we describe two architectures for compressive light field imaging that require relatively few photon-efficient measurements to obtain a high-resolution estimate of the light field while reducing the overall exposure time. Our simulation study shows that, compressive light field imagers using the principal component (PC) measurement basis require four times fewer measurements and three times shorter exposure time compared to a conventional light field imager in order to achieve an equivalent light field reconstruction quality.

1. Light tower/keeper's house and abandoned light tower, view northwest, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Light tower/keeper's house and abandoned light tower, view northwest, south southeast and east northeast sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

2. Abandoned light tower and keeper's house/light tower, view southeast, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Abandoned light tower and keeper's house/light tower, view southeast, north northwest and west southwest sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

Sculpting with light: Light/matter interactions in biocompatible polymers

NASA Astrophysics Data System (ADS)

Applegate, Matthew B.

When light interacts with matter either the light or the material can be changed. This dissertation focuses on light/matter interaction in silk fibroin and its utility for biomedical applications. Silk, a natural biocompatible, biodegradable polymer, has a large 3-photon absorption cross-section which allows modest peak intensity light to cause significant multiphoton absorption. This absorption allows voids to be formed with three dimensional control within soft, transparent silk hydrogels. A theoretical model of the void formation process is developed to allow the size of the voids to be predicted for a range of laser and sample parameters. Arbitrary 3D patterns are created in silk gels that allow cells to penetrate into the bulk of the gel both in vitro and in vivo. To explore how silk can be used to alter light, the creation of step-index optical waveguides, formed by encapsulating a silk film within a silk hydrogel, is described. These waveguides allow light to be delivered to targets through several centimeters of highly scattering biological tissue. Finally, the interaction of light with riboflavin is used to photocrosslink silk to form solid structures, rather than voids. The mechanism of crosslinking to be driven by radicalized tyrosine residues resulting in the formation of dityrosine bonds which lead to the gelation of a liquid silk solution. Riboflavin is a versatile photoinitiator and can be used to crosslink collagen as well as silk, which allows silk to be crosslinked directly to corneal collagen. When applied to the eye, an artificial corneal layer is formed which has the potential to treat various corneal diseases and allow for risk-free laser vision correction. These studies show the versatility of light-based processing of silk for a wide variety of medical applications.

Illuminating system and method for specialized and decorative lighting using liquid light guides

DOEpatents

Zorn, Carl J.; Kross, Brian J.; Majewski, Stanislaw; Wojcik, Randolph F.

1998-01-01

The present invention comprises an illumination system for specialized decorative lighting including a light source, a flexible plastic tube sheath for distributing the light to a remote location, a transparent liquid core filling the tube that has an index of refraction greater than that of the plastic tube and an arrangement where light coupled from the light source is caused to leak from the liquid light guide at desired locations for the purposes of specialized lighting, such as underwater illumination in swimming pools.

Pollution-free road lighting

NASA Astrophysics Data System (ADS)

Schreuder, Duco A.

They relate to reducing road accidents and some forms of crime but also enhance the social safety of residents and pedestrians and the amenity for residents. Road traffic in developing countries is much more hazardous than in industrialized countries. Accident rates in 'low' income countries may be as much as 35 times higher than in 'high' income countries. Thus, it might be much more cost-effective to light roads in the developing world than in the industrialized world. Fighting light pollution is more pressing in developing countries as most of the major high-class astronomical observatories are there. Astronomical observations are disturbed by light from outdoor lighting installations, part of which is scattered in the atmosphere to form 'sky glow'. The International Lighting Commission CIE has published a Technical Report giving general guidance for lighting designers and policy makers on the reduction of the sky glow. Lighting improves visibility, essential for almost all human activity. However, light that hits the road contributes to visibility only if it is reflected. In poorly designed lighting equipment much of the lumen output of the lamps is sent directly upwards. This can be avoided by properly defined light fittings. The light output of fittings is determined by their optical quality and by the installation maintenance factor. Open fittings are to be preferred. If mounted horizontally, they make street lighting with the least light pollution.

Estimation of light source colours for light pollution assessment.

PubMed

Ziou, D; Kerouh, F

2018-05-01

The concept of the smart city raised several technological and scientific issues including light pollution. There are various negative impacts of light pollution on economy, ecology, and heath. This paper deals with the census of the colour of light emitted by lamps used in a city environment. To this end, we derive a light bulb colour estimator based on Bayesian reasoning, directional data, and image formation model in which the usual concept of reflectance is not used. All choices we made are devoted to designing an algorithm which can be run almost in real-time. Experimental results show the effectiveness of the proposed approach. Copyright © 2018 Elsevier Ltd. All rights reserved.

Illuminating system and method for specialized and decorative lighting using liquid light guides

DOEpatents

Zorn, C.J.; Kross, B.J.; Majewski, S.; Wojcik, R.F.

1998-08-25

The present invention comprises an illumination system for specialized decorative lighting including a light source, a flexible plastic tube sheath for distributing the light to a remote location, a transparent liquid core filling the tube that has an index of refraction greater than that of the plastic tube and an arrangement where light coupled from the light source is caused to leak from the liquid light guide at desired locations for the purposes of specialized lighting, such as underwater illumination in swimming pools. 5 figs.

Enriching lighting design.

PubMed

Brawley, Elizabeth C

2009-01-01

Good lighting is perhaps the most important and least understood element in designing healthcare environments. Both physically and mentally challenged individuals become more vulnerable and dependent on their environment to compensate for sensory impairments, including dimming eyesight, which interferes to some degree with daily activities as well as social and leisure activities - the things that provide emotional and social well-being. Too few building designs today result in lighting that meets the needs of these individuals, regardless of age. Typical lighting in most care environments is inadequate to meet lighting needs affecting both vision and the photobiological (non-visual) needs of synchronization of circadian rhythm, which impacts sleep and depression. Well-designed lighting is one of the most important design elements that will support an individual's ability to perform normal daily activities and decrease the level of disability associated with these impairments. Daylight contains the spectrum to which the circadian clock is most sensitive and provides higher light levels during the day. Easily accessible outdoor gardens encourage individuals outside, providing the necessary regular exposure to direct bright light that sunlight provides. The combination good interior lighting and regular daylight exposure contributes to regaining and maintaining an active and fulfilling lifestyle - greatly improving quality of life.

Association between light-to-dark changes in angle width and iris parameters in light, dark and changes from light-to-dark conditions.

PubMed

Lee, Roland Y; Lin, Shuai-Chun; Chen, Rebecca I; Barbosa, Diego T; Lin, Shan C

2016-09-01

To evaluate the association between light-to-dark changes in angle width parameters and iris parameters in light, dark and changes from light-to-dark conditions. In this prospective, cross-sectional study, anterior segment optical coherence tomography images, obtained under light and dark conditions, were analysed to determine angle opening distance measured at 500 μm from the scleral spur (AOD500), trabecular-iris space area at 500 μm from the scleral spur (TISA500), iris thickness measured at 750 μm from the scleral spur (IT750), iris thickness measured at 2000 μm from the scleral spur (IT2000), iris area (IArea) and pupil diameter (PD). Multivariable linear mixed-effect regression models were used to evaluate the association between light-to-dark changes in angle width parameters (AOD500, TISA500) and iris parameters (IT750, IT2000, IArea, PD) in light, dark and changes from light-to-dark conditions. 534 eyes from 314 non-glaucomatous subjects were analysed. IT750, IT2000, IArea and PD in light conditions were significantly associated with light-to-dark changes in AOD500 (p<0.05). IT750, IT2000 and IArea in light conditions were significantly associated with light-to-dark changes in TISA500 (p<0.05). IT750 in dark conditions was significantly associated with light-to-dark changes in AOD500 and TISA500 (p<0.05). Light-to-dark changes in IT2000, IArea and PD were significantly associated with light-to-dark changes in AOD500 (p<0.05). Light-to-dark changes in IArea were significantly associated with light-to-dark changes in TISA500 (p<0.05). Evaluation of iris parameters in light, dark and changes from light-to-dark conditions demonstrated that IT750, IT2000, IArea and PD in light conditions are significant predictors of light-to-dark changes in angle width. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A SOLAR FLARE DISTURBING A LIGHT WALL ABOVE A SUNSPOT LIGHT BRIDGE

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

Hou, Yijun; Zhang, Jun; Li, Ting

With the high-resolution data from the Interface Region Imaging Spectrograph , we detect a light wall above a sunspot light bridge in the NOAA active region (AR) 12403. In the 1330 Å slit-jaw images, the light wall is brighter than the ambient areas while the wall top and base are much brighter than the wall body, and it keeps oscillating above the light bridge. A C8.0 flare caused by a filament activation occurred in this AR with the peak at 02:52 UT on 2015 August 28, and the flare’s one ribbon overlapped the light bridge, which was the observational basemore » of the light wall. Consequently, the oscillation of the light wall was evidently disturbed. The mean projective oscillation amplitude of the light wall increased from 0.5 to 1.6 Mm before the flare and decreased to 0.6 Mm after the flare. We suggest that the light wall shares a group of magnetic field lines with the flare loops, which undergo a magnetic reconnection process, and they constitute a coupled system. When the magnetic field lines are pushed upward at the pre-flare stage, the light wall turns to the vertical direction, resulting in the increase of the light wall’s projective oscillation amplitude. After the magnetic reconnection takes place, a group of new field lines with smaller scales are formed underneath the reconnection site, and the light wall inclines. Thus, the projective amplitude notably decrease at the post-flare stage.« less

A method for improving the light intensity distribution in dental light-curing units.

PubMed

Arikawa, Hiroyuki; Takahashi, Hideo; Minesaki, Yoshito; Muraguchi, Kouichi; Matsuyama, Takashi; Kanie, Takahito; Ban, Seiji

2011-01-01

A method for improving the uniformity of the radiation light from dental light-curing units (LCUs), and the effect on the polymerization of light-activated composite resin are investigated. Quartz-tungsten halogen, plasma-arc, and light-emitting diode LCUs were used, and additional optical elements such as a mixing tube and diffusing screen were employed to reduce the inhomogeneity of the radiation light. The distribution of the light intensity from the light guide tip was measured across the guide tip, as well as the distribution of the surface hardness of the light-activated resin emitted with the LCUs. Although the additional optical elements caused 13.2-25.9% attenuation of the light intensity, the uniformity of the light intensity of the LCUs was significantly improved in the modified LCUs, and the uniformity of the surface hardness of the resin was also improved. Our results indicate that the addition of optical elements to the LCU may be a simple and effective method for reducing inhomogeneity in radiation light from the LCUs.

Catching the Light - The Entwined History of Light and Mind

NASA Astrophysics Data System (ADS)

Zajonc, Arthur

1995-04-01

In 1910, the surgeons Moreau and LePrince wrote about their successful operation on an eight-year-old boy who had been blind since birth because of cataracts. When the boy's eyes were healed they removed the bandages and, waving a hand in front of the child's physically perfect eyes, asked him what he saw. "I don't know," was his only reply. What he saw was only a varying brightness in front of him. However, when allowed to touch the hand as it began to move, he cried out in a voice of triumph, "It's moving!" He could feel it move, but he still needed laboriously to learn to see it move. Light and eyes were not enough to grant him sight. How, then, do we see? What's the difference between seeing and perception? What is light? From ancient times to the present, from philosophers to quantum physicists, nothing has so perplexed, so fascinated, so captivated the mind as the elusive definition of light. In Catching the Light , Arthur Zajonc takes us on an epic journey into history, tracing how humans have endeavored to understand the phenomenon of light. Blending mythology, religion, science, literature, and painting, Zajonc reveals in poetic detail the human struggle to identify the vital connection between the outer light of nature and the inner light of the human spirit. He explains the curiousness of the Greeks' blue and green "color blindness": Odysseus gazing longingly at the "wine-dark sea"; the use of chloros (green) as the color of honey in Homer's Odessey ; and Euripides' use of the color green to describe the hue of tears and blood. He demonstrates the complexity of perception through the work of Paul Cézanne--the artist standing on the bank of a river, painting the same scene over and over again, the motifs multiplying before his eyes. And Zajonc goes on to show how our quest for an understanding of light, as well as the conclusions we draw, reveals as much about the nature of our own psyche as it does about the nature of light itself. For the ancient

White light Sagnac interferometer—a common (path) tale of light

NASA Astrophysics Data System (ADS)

Schwartz, Eyal

2017-11-01

White or polychromatic light sources are vastly abundant in nature and lie in our most basic understanding of the theory of light, beginning from stars like our Sun and extending to every common household light bulb or street lamp. In this paper, I present concepts of white light interferometery using a common-path Sagnac interferometer, manifested in a straightforward laboratory experiment. I further show the use of this as a Fourier transform spectrometer while presenting a basic overview of the theoretical concepts and spectrum of different light sources obtained experimentally. This work, both experimentally and analytically, is suitable for upper-level undergraduate physics or engineering courses where electromagnetic theory and optics are discussed. The experiment and theory presents important deep concepts and aspects in modern optics and physics that every science student should acquire.

Device structure for OLED light device having multi element light extraction and luminescence conversion layer

DOEpatents

Antoniadis,; Homer, Krummacher [Mountain View, CA; Claus, Benjamin [Regensburg, DE

2008-01-22

An apparatus such as a light source has a multi-element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

Integrated Performance of Next Generation High Data Rate Receiver and AR4JA LDPC Codec for Space Communications

NASA Technical Reports Server (NTRS)

Cheng, Michael K.; Lyubarev, Mark; Nakashima, Michael A.; Andrews, Kenneth S.; Lee, Dennis

2008-01-01

Low-density parity-check (LDPC) codes are the state-of-the-art in forward error correction (FEC) technology that exhibits capacity approaching performance. The Jet Propulsion Laboratory (JPL) has designed a family of LDPC codes that are similar in structure and therefore, leads to a single decoder implementation. The Accumulate-Repeat-by-4-Jagged- Accumulate (AR4JA) code design offers a family of codes with rates 1/2, 2/3, 4/5 and lengths 1024, 4096, 16384 information bits. Performance is less than one dB from capacity for all combinations.Integrating a stand-alone LDPC decoder with a commercial-off-the-shelf (COTS) receiver faces additional challenges than building a single receiver-decoder unit from scratch. In this work, we outline the issues and show that these additional challenges can be over-come by simple solutions. To demonstrate that an LDPC decoder can be made to work seamlessly with a COTS receiver, we interface an AR4JA LDPC decoder developed on a field-programmable gate array (FPGA) with a modern high data rate receiver and mea- sure the combined receiver-decoder performance. Through optimizations that include an improved frame synchronizer and different soft-symbol scaling algorithms, we show that a combined implementation loss of less than one dB is possible and therefore, most of the coding gain evidence in theory can also be obtained in practice. Our techniques can benefit any modem that utilizes an advanced FEC code.

Lighting theory and luminous characteristics of white light-emitting diodes

NASA Astrophysics Data System (ADS)

Uchida, Yuji; Taguchi, Tsunemasa

2005-12-01

A near-ultraviolet (UV)-based white light-emitting diode (LED) lighting system linked with a semiconductor InGaN LED and compound phosphors for general lighting applications is proposed. We have developed for the first time a novel type of high-color rendering index (Ra) white LED light source, which is composed of near-UV LED and multiphosphor materials showing orange (O), yellow (Y), green (G), and blue (B) emissions. The white LED shows the superior characteristics of luminous efficacy and high Ra to be about 40 lm/W and 93, respectively. Luminous and chromaticity characteristics, and their spectral distribution of the present white LED can be evaluated using the multipoint LED light source theory. It is revealed that the OYGB white LED can provide better irradiance properties than that of conventional white LEDs. Near-UV white LED technologies, in conjunction with phosphor blends, can offer superior color uniformity, high Ra, and excellent light quality. Consequently we are carrying out a "white LEDs for medical applications" program in the second phase of this national project from 2004 to 2009.

Perception of low red:far-red ratio compromises both salicylic acid- and jasmonic acid-dependent pathogen defences in Arabidopsis.

PubMed

de Wit, Mieke; Spoel, Steven H; Sanchez-Perez, Gabino F; Gommers, Charlotte M M; Pieterse, Corné M J; Voesenek, Laurentius A C J; Pierik, Ronald

2013-07-01

In dense stands of plants, such as agricultural monocultures, plants are exposed simultaneously to competition for light and other stresses such as pathogen infection. Here, we show that both salicylic acid (SA)-dependent and jasmonic acid (JA)-dependent disease resistance is inhibited by a simultaneously reduced red:far-red light ratio (R:FR), the early warning signal for plant competition. Conversely, SA- and JA-dependent induced defences did not affect shade-avoidance responses to low R:FR. Reduced pathogen resistance by low R:FR was accompanied by a strong reduction in the regulation of JA- and SA-responsive genes. The severe inhibition of SA-responsive transcription in low R:FR appeared to be brought about by the repression of SA-inducible kinases. Phosphorylation of the SA-responsive transcription co-activator NPR1, which is required for full induction of SA-responsive transcription, was indeed reduced and may thus play a role in the suppression of SA-mediated defences by low R:FR-mediated phytochrome inactivation. Our results indicate that foraging for light through the shade-avoidance response is prioritised over plant immune responses when plants are simultaneously challenged with competition and pathogen attack. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Circadian light

PubMed Central

2010-01-01

The present paper reflects a work in progress toward a definition of circadian light, one that should be informed by the thoughtful, century-old evolution of our present definition of light as a stimulus for the human visual system. This work in progress is based upon the functional relationship between optical radiation and its effects on nocturnal melatonin suppression, in large part because the basic data are available in the literature. Discussed here are the fundamental differences between responses by the visual and circadian systems to optical radiation. Brief reviews of photometry, colorimetry, and brightness perception are presented as a foundation for the discussion of circadian light. Finally, circadian light (CLA) and circadian stimulus (CS) calculation procedures based on a published mathematical model of human circadian phototransduction are presented with an example. PMID:20377841

Beacon system based on light-emitting diode sources for runways lighting

NASA Astrophysics Data System (ADS)

Montes, Mario González; Vázquez, Daniel; Fernandez-Balbuena, Antonio A.; Bernabeu, Eusebio

2014-06-01

New aeronautical ground lighting techniques are becoming increasingly important to ensure the safety and reduce the maintenance costs of the plane's tracks. Until recently, tracks had embedded lighting systems whose sources were based on incandescent lamps. But incandescent lamps have several disadvantages: high energy consumption and frequent breakdowns that result in high maintenance costs (lamp average life-time is ˜1500 operating hours) and the lamp's technology has a lack of new lighting functions, such as signal handling and modification. To solve these problems, the industry has developed systems based on light-emitting diode (LED) technology with improved features: (1) LED lighting consumes one tenth the power, (2) it improves preventive maintenance (an LED's lifetime range is between 25,000 and 100,000 hours), and (3) LED lighting technology can be controlled remotely according to the needs of the track configuration. LEDs have been in use for more than three decades, but only recently, around 2002, have they begun to be used as visual aids, representing the greatest potential change for airport lighting since their inception in the 1920s. Currently, embedded LED systems are not being broadly used due to the specific constraints of the rules and regulations of airports (beacon dimensions, power system technology, etc.). The fundamental requirements applied to embedded lighting systems are to be hosted on a volume where the dimensions are usually critical and also to integrate all the essential components for operation. An embedded architecture that meets the lighting regulations for airport runways is presented. The present work is divided into three main tasks: development of an optical system to optimize lighting according to International Civil Aviation Organization, manufacturing prototype, and model validation.

Blue-enriched office light competes with natural light as a zeitgeber.

PubMed

Vetter, Céline; Juda, Myriam; Lang, Dieter; Wojtysiak, Andreas; Roenneberg, Till

2011-09-01

Circadian regulation of human physiology and behavior (eg, body temperature or sleep-timing), depends on the "zeitgeber" light that synchronizes them to the 24-hour day. This study investigated the effect of changing light temperature at the workplace from 4000 Kelvin (K) to 8000 K on sleep-wake and activity-rest behavior. An experimental group (N=27) that experienced the light change was compared with a non-intervention group (N=27) that remained in the 4000 K environment throughout the 5-week study period (14 January to 17 February). Sleep logs and actimetry continuously assessed sleep-wake behavior and activity patterns. Over the study period, the timing of sleep and activity on free days steadily advanced parallel to the seasonal progression of sunrise in the non-intervention group. In contrast, the temporal pattern of sleep and activity in the experimental group remained associated with the constant onset of work. The results suggest that artificial blue-enriched light competes with natural light as a zeitgeber. While subjects working under the warmer light (4000 K) appear to entrain (or synchronize) to natural dawn, the subjects who were exposed to blue-enriched (8000 K) light appear to entrain to office hours. The results confirm that light is the dominant zeitgeber for the human clock and that its efficacy depends on spectral composition. The results also indicate that blue-enriched artificial light is a potent zeitgeber that has to be used with diligence.

Light Motives.

ERIC Educational Resources Information Center

Filler, Martin

1979-01-01

The new energy consciousness has led to a thorough reevaluation of how artificial lighting can be used wisely, while other researchers have explored the potential of daylighting as an alternative interior light source. (Author/MLF)

White Light Stray Light Test of the SOHO UVCS

NASA Technical Reports Server (NTRS)

Gardner, L. N.; Gardner, L. N.; Fineschi, S.

1998-01-01

During the late stages of the integration phase of the Ultraviolet Coronagraph Spectrometer (UVCS) instrument for the Solar and Heliospheric Observatory (SOHO) at MATRA-Marconi in Toulouse, France, SOHO Project management at Goddard Space Flight Center (GSFC) became concerned that the elaborate stray light rejection system for the instrument had not been tested and might possibly be misaligned such that the instrument could not deliver promised scientific returns. A white light stray light test, which would place an upper bound on the value of UVCS's stray light rejection capability, was commissioned, conceived, and carried out. This upper bound value would be indicative of the weakest coronal features the spectrometer would be capable of discerning. The test was rapidly developed at GSFC in coordination with science team members from Harvard-Smithsonian Center for Astrophysics (CFA) and was carried out at MATRA in late February 1995. The outcome of this test helped to justify similar, much desired tests with visible and far ultraviolet light at CFA in a facility specifically designed to perform such testing.

Comparison of light transmittance in different thicknesses of zirconia under various light curing units

PubMed Central

Egilmez, Ferhan; Ergun, Gulfem

2012-01-01

PURPOSE The objective of this study was to compare the light transmittance of zirconia in different thicknesses using various light curing units. MATERIALS AND METHODS A total of 21 disc-shaped zirconia specimens (5 mm in diameter) in different thicknesses (0.3, 0.5 and 0.8 mm) were prepared. The light transmittance of the specimens under three different light-curing units (quartz tungsten halogen, light-emitting diodes and plasma arc) was compared by using a hand-held radiometer. Statistical significance was determined using two-way ANOVA (α=.05). RESULTS ANOVA revealed that thickness of zirconia and light curing unit had significant effects on light transmittance (P<.001). CONCLUSION Greater thickness of zirconia results in lower light transmittance. Light-emitting diodes light-curing units might be considered as effective as Plasma arc light-curing units or more effective than Quartz-tungsten-halogen light-curing units for polymerization of the resin-based materials. PMID:22737314

Green light in photomorphogenic development

NASA Astrophysics Data System (ADS)

Maruhnich, Stefanie Anne

Light quality, quantity, and duration provide essential environmental cues that shape plant growth and development. Over the last century, researchers have worked to discover how plants sense, integrate, and respond to red, blue, and far-red light. Green light is often considered a “benign” wavelength with little to no effect in plant development. However, sparse experiments in the literature demonstrate that green effects are often counterintuitive to normal light responses and oppose red- and blue-light-induced responses. Green light effects on plant growth and development are described here through the use of custom, tunable LED, light-emitting diode, chambers. These light sources allow for specific light qualities and quantities to be administered. The effects of green wavebands were assessed when red and blue photomorphogenic systems were active to answer the question: Are the effects of an inhibitor (green light) more evident in the presence of inducers (red and blue light)? In seedlings, supplemental green light increased hypocotyl elongation opposite to classical inhibition of hypocotyl elongation associated with growth in light and induced by red and blue wavebands. Results indicate that added green light induced a reversion of light-grown phenotypes. In mature plants, supplemental green light induced phenotypes typical of the shade-avoidance syndrome, including elongated petioles, smaller leaf areas, and leaf hyponasty. These responses are typical of lower-light conditions or far-red enriched environments. Contrary to far-red-light-induced shade-avoidance, data indicate green delays flowering. In Arabidopsis and strawberry plants, anthocyanin levels also decreased when green light was added to red and blue light treatments, which is again opposite to normal light-induced phenotypes. Photoreceptor mutants were tested and indicate green light effects in early development are cryptochromedependent. However, green-light-induced shade-avoidance responses

Architectural Physics: Lighting.

ERIC Educational Resources Information Center

Hopkinson, R. G.

The author coordinates the many diverse branches of knowledge which have dealt with the field of lighting--physiology, psychology, engineering, physics, and architectural design. Part I, "The Elements of Architectural Physics", discusses the physiological aspects of lighting, visual performance, lighting design, calculations and measurements of…

Light intensity compressor

DOEpatents

Rushford, Michael C.

1990-02-06

In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

Light intensity compressor

DOEpatents

Rushford, Michael C.

1990-01-01

In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

Light up My Life

ERIC Educational Resources Information Center

Kellett, Sarah

2015-01-01

Simply stated, light is nature's way of transferring energy through space. Discussions of light usually refer to visible light, which is perceived by the human eye and is responsible for the sense of sight. We see however, only a small part of the light spectrum. Light connects us as we sit and tell yarns around camp fires. Yet, one in every four…

OSCILLATING LIGHT WALL ABOVE A SUNSPOT LIGHT BRIDGE

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

Yang, Shuhong; Zhang, Jun; Jiang, Fayu

With the high tempo-spatial Interface Region Imaging Spectrograph 1330 Å images, we find that many bright structures are rooted in the light bridge of NOAA 12192, forming a light wall. The light wall is brighter than the surrounding areas, and the wall top is much brighter than the wall body. The New Vacuum Solar Telescope Hα and the Solar Dynamics Observatory 171 and 131 Å images are also used to study the light-wall properties. In 1330, 171, and 131 Å, the top of the wall has a higher emission, while in the Hα line, the wall-top emission is very low.more » The wall body corresponds to bright areas in 1330 Å and dark areas in the other lines. The top of the light wall moves upward and downward successively, performing oscillations in height. The deprojected mean height, amplitude, oscillation velocity, and the dominant period are determined to be 3.6 Mm, 0.9 Mm, 15.4 km s{sup −1}, and 3.9 minutes, respectively. We interpret the oscillations of the light wall as the leakage of p-modes from below the photosphere. The constant brightness enhancement of the wall top implies the existence of some kind of atmospheric heating, e.g., via the persistent small-scale reconnection or the magneto-acoustic waves. In another series of 1330 Å images, we find that the wall top in the upward motion phase is significantly brighter than in the downward phase. This kind of oscillation may be powered by the energy released due to intermittent impulsive magnetic reconnection.« less

Green light drives leaf photosynthesis more efficiently than red light in strong white light: revisiting the enigmatic question of why leaves are green.

PubMed

Terashima, Ichiro; Fujita, Takashi; Inoue, Takeshi; Chow, Wah Soon; Oguchi, Riichi

2009-04-01

The literature and our present examinations indicate that the intra-leaf light absorption profile is in most cases steeper than the photosynthetic capacity profile. In strong white light, therefore, the quantum yield of photosynthesis would be lower in the upper chloroplasts, located near the illuminated surface, than that in the lower chloroplasts. Because green light can penetrate further into the leaf than red or blue light, in strong white light, any additional green light absorbed by the lower chloroplasts would increase leaf photosynthesis to a greater extent than would additional red or blue light. Based on the assessment of effects of the additional monochromatic light on leaf photosynthesis, we developed the differential quantum yield method that quantifies efficiency of any monochromatic light in white light. Application of this method to sunflower leaves clearly showed that, in moderate to strong white light, green light drove photosynthesis more effectively than red light. The green leaf should have a considerable volume of chloroplasts to accommodate the inefficient carboxylation enzyme, Rubisco, and deliver appropriate light to all the chloroplasts. By using chlorophylls that absorb green light weakly, modifying mesophyll structure and adjusting the Rubisco/chlorophyll ratio, the leaf appears to satisfy two somewhat conflicting requirements: to increase the absorptance of photosynthetically active radiation, and to drive photosynthesis efficiently in all the chloroplasts. We also discuss some serious problems that are caused by neglecting these intra-leaf profiles when estimating whole leaf electron transport rates and assessing photoinhibition by fluorescence techniques.

A lighting assembly based on red and blue light-emitting diodes as a lighting source for space agriculture

NASA Astrophysics Data System (ADS)

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

Light-emitting diodes (LEDs) are a promising lighting source for space agriculture due to their high efficiency, longevity, safety, and other factors. Assemblies based on red and blue LEDs have been recommended in literature, although not all plants show sufficient productivity in such lighting conditions. Adding of green LEDs proposed in some works was aimed at psychological support for the crew, and not at the improvement of plant growth. We studied the growth and the state of the photosynthetic apparatus in Chinese cabbage (Brassica chinensis L.) plants grown under red (650 nm) and blue (470 nm) light-emitting diodes (LEDs). Plants grown under a high-pressure sodium lamp (HPS lamp) were used as a control. The plants were illuminated with two photosynthetic photon flux levels: nearly 400 µE and about 100 µE. Plants grown under LEDs with 400 µE level, as compared to control plants, showed lower fresh weight, edible biomass, growth rate, and sugar content. The difference in fresh weight and edible biomass was even more pronounced in plants grown with 100 µE level; the data indicate that the adaptability of the test plants to insufficient lighting decreased. Under LEDs, we observed the decreasing of root growth and the absence of transition to the flowering stage, which points to a change in the hormonal balance in plants grown in such lighting conditions. We also found differences in the functioning of the photosynthetic apparatus and its reaction to a low lighting level. We have concluded that a lighting assembly with red and blue LEDs only is insufficient for the plant growth and productivity, and can bring about alterations in their adaptive and regulatory mechanisms. Further studies are needed to optimize the lighting spectrum for space agriculture, taking into account the photosynthetic, phototropic and regulatory roles of light. Using white LEDs or adding far-red and green LEDs might be a promising approach.

Effect of light dispersion of LED curing lights on resin composite polymerization.

PubMed

Vandewalle, Kraig S; Roberts, Howard W; Andrus, Jeffrey L; Dunn, William J

2005-01-01

This study evaluated the effect of light dispersion of halogen and LED curing lights on resin composite polymerization. One halogen (Optilux 501, SDS/Kerr, Orange, CA, USA) and five light-emitting diode (LED) curing lights (SmartLite iQ, Dentsply Caulk, Milford, DE, USA; LEDemetron 1, SDS/Kerr; FLASHlite 1001, Discus Dental, Culver City, CA, USA; UltraLume LED 5, Ultradent Products, South Jordan, UT, USA; Allegro, Den-Mat, Santa Maria, CA, USA) were used in this study. Specimens (8 mm diameter by 2 mm thick) were made in polytetrafluoroethylene molds using hybrid (Z100, 3M ESPE, St. Paul, MN, USA) and microfill (A110, 3M ESPE) composite resins. The top surface was polymerized for 5 seconds with the curing light guide tip positioned at a distance of 1 and 5 mm. Degree of conversion (DC) of the composite specimens was analyzed on the bottom surface using micro-Fourier Transform Infrared (FTIR) spectroscopy (Perkin-Elmer FTIR Spectrometer, Wellesley, PA, USA) 10 minutes after light activation. DC at the bottom of the 2 mm specimen was expressed as a percentage of the mean maximum DC. Five specimens were created per curing light and composite type (n=5). Percent mean DC ratios and SDs were calculated for each light under each testing condition. Data were analyzed by analysis of variance (ANOVA)/Tukey's test (alpha = .05). A beam analyzer (LBA-700, Spiricon, Logan, UT, USA) was used to record the emitted light from the curing lights at 0 and 5 mm distances (n=5). A Top Hat factor was used to compare the quality of the emitted beam profile (LBA/PC, Spiricon). The divergence angle from vertical was also determined in the x- and y-axes (LBA/PC). Mean values and SDs were calculated for each light under each testing condition (0 and 5 mm, x- and y-axes) and analyzed by a two-way ANOVA/Tukey's test (alpha = .05). For DC ratios, significant differences were found based on curing light and curing distance (p < .05). At 1 mm, Optilux 501 and FLASHlite 1001 produced significantly

Lighting the Learning Environment.

ERIC Educational Resources Information Center

Fielding, Randall

2000-01-01

Explores the benefits and pitfalls of day lighting, indirect light, and full-spectrum lamps for general illumination and accent lighting in classrooms. Discussions include lighting considerations in areas where computers are used and fixture cost factors versus efficiency. (GR)

Light-controlled motility in prokaryotes and the problem of directional light perception

PubMed Central

Wilde, Annegret

2017-01-01

Abstract The natural light environment is important to many prokaryotes. Most obviously, phototrophic prokaryotes need to acclimate their photosynthetic apparatus to the prevailing light conditions, and such acclimation is frequently complemented by motility to enable cells to relocate in search of more favorable illumination conditions. Non-phototrophic prokaryotes may also seek to avoid light at damaging intensities and wavelengths, and many prokaryotes with diverse lifestyles could potentially exploit light signals as a rich source of information about their surroundings and a cue for acclimation and behavior. Here we discuss our current understanding of the ways in which bacteria can perceive the intensity, wavelength and direction of illumination, and the signal transduction networks that link light perception to the control of motile behavior. We discuss the problems of light perception at the prokaryotic scale, and the challenge of directional light perception in small bacterial cells. We explain the peculiarities and the common features of light-controlled motility systems in prokaryotes as diverse as cyanobacteria, purple photosynthetic bacteria, chemoheterotrophic bacteria and haloarchaea. PMID:29077840

Light-controlled motility in prokaryotes and the problem of directional light perception.

PubMed

Wilde, Annegret; Mullineaux, Conrad W

2017-11-01

The natural light environment is important to many prokaryotes. Most obviously, phototrophic prokaryotes need to acclimate their photosynthetic apparatus to the prevailing light conditions, and such acclimation is frequently complemented by motility to enable cells to relocate in search of more favorable illumination conditions. Non-phototrophic prokaryotes may also seek to avoid light at damaging intensities and wavelengths, and many prokaryotes with diverse lifestyles could potentially exploit light signals as a rich source of information about their surroundings and a cue for acclimation and behavior. Here we discuss our current understanding of the ways in which bacteria can perceive the intensity, wavelength and direction of illumination, and the signal transduction networks that link light perception to the control of motile behavior. We discuss the problems of light perception at the prokaryotic scale, and the challenge of directional light perception in small bacterial cells. We explain the peculiarities and the common features of light-controlled motility systems in prokaryotes as diverse as cyanobacteria, purple photosynthetic bacteria, chemoheterotrophic bacteria and haloarchaea. © FEMS 2017.

Combination Light

NASA Astrophysics Data System (ADS)

1990-01-01

The Rayovac TANDEM is an advanced technology combination work light and general purpose flashlight that incorporates several NASA technologies. The TANDEM functions as two lights in one. It features a long range spotlight and wide angle floodlight; simple one-hand electrical switching changes the beam from spot to flood. TANDEM developers made particular use of NASA's extensive research in ergonomics in the TANDEM's angled handle, convenient shape and different orientations. The shatterproof, water resistant plastic casing also draws on NASA technology, as does the shape and beam distance of the square diffused flood. TANDEM's heavy duty magnet that permits the light to be affixed to any metal object borrows from NASA research on rare earth magnets that combine strong magnetic capability with low cost. Developers used a NASA-developed ultrasonic welding technique in the light's interior.

Measurement of one-way velocity of light and light-year

NASA Astrophysics Data System (ADS)

Chen, Shao-Guang

For space science and astronomy the fundamentality of one-way velocity of light (OWVL) is selfevident. The measurement of OWVL (distance / interval) and the clock synchronization with light-signal transfer make a logical circulation. This means that OWVL could not be directly measured but only come indirectly from astronomical method (Romer's Io eclipse and Bradley's sidereal aberration). Furthermore, the light-year by definitional OWVL and the trigonometry distance with AU are also un-measurable. In this report two methods of clock synchronization to solve this problem were proposed: The arriving-time difference of longitudinal-transverse wave (Ts - Tp) or ordinary-extraordinary light (Te - To) is measured by single clock at one end of a dual-speed transmission-line, the signal transmission-delay (from sending-end time Tx to receiving-end time Tp or To) calculated with wave-speed ratio is: (Tp -Tx) = (Ts -Tp) / ((Vp / Vs) - 1) or: (To -Tx) = (Te - To) / ((Vo / Ve ) - 1), where (Vp / Vs) = (E / k) 1/2 is Yang's / shear elastic-modulus ratio obtained by comparing two strains at same stress, (Vo / Ve) = (ne / no) is extraordinary/ordinary light refractive-index ratio obtained by comparing two deflection-angles. Then, two clocks at transmission-line two ends can be synchronized directly to measure the one-way velocity of light and light-year, which work as one earthquakestation with single clock measures first-shake-time and the distance to epicenter. The readings Na and Nb of two counters Ca and Cb with distance L are transferred into a computer C by two leads with transmission-delay Tac and Tbc respectively. The computer progressing subtraction operation exports steady value: (Nb - Na) = f (Ta - Tb ) + f (Tac - Tbc ), where f is the frequency of light-wave always passing Ca and Cb, Ta and Tb are the count-start time of Ca and Cb respectively. From the transmission-delay possess the spatial translational and rotational invariability, the computer exports steady value

Effects of weather conditions, light conditions, and road lighting on vehicle speed.

PubMed

Jägerbrand, Annika K; Sjöbergh, Jonas

2016-01-01

Light conditions are known to affect the number of vehicle accidents and fatalities but the relationship between light conditions and vehicle speed is not fully understood. This study examined whether vehicle speed on roads is higher in daylight and under road lighting than in darkness, and determined the combined effects of light conditions, posted speed limit and weather conditions on driving speed. The vehicle speed of passenger cars in different light conditions (daylight, twilight, darkness, artificial light) and different weather conditions (clear weather, rain, snow) was determined using traffic and weather data collected on an hourly basis for approximately 2 years (1 September 2012-31 May 2014) at 25 locations in Sweden (17 with road lighting and eight without). In total, the data included almost 60 million vehicle passes. The data were cleaned by removing June, July, and August, which have different traffic patterns than the rest of the year. Only data from the periods 10:00 A.M.-04:00 P.M. and 06:00 P.M.-10:00 P.M. were used, to remove traffic during rush hour and at night. Multivariate adaptive regression splines was used to evaluate the overall influence of independent variables on vehicle speed and nonparametric statistical testing was applied to test for speed differences between dark-daylight, dark-twilight, and twilight-daylight, on roads with and without road lighting. The results show that vehicle speed in general depends on several independent variables. Analyses of vehicle speed and speed differences between daylight, twilight and darkness, with and without road lighting, did not reveal any differences attributable to light conditions. However, vehicle speed decreased due to rain or snow and the decrease was higher on roads without road lighting than on roads with lighting. These results suggest that the strong association between traffic accidents and darkness or low light conditions could be explained by drivers failing to adjust their

Internal heat gain from different light sources in the building lighting systems

NASA Astrophysics Data System (ADS)

Suszanowicz, Dariusz

2017-10-01

EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output) were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

Light Emitting Diode (LED)

NASA Technical Reports Server (NTRS)

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.

The NICU Lighted Environment

PubMed Central

Rea, Mark S.; Figueiro, Mariana G.

2016-01-01

Lighting technologies are rapidly evolving, creating many opportunities for good lighting within the NICU. With the widespread adoption of advanced solid-state lighting technologies, lighting no longer needs to be static. Rather, lighting systems can be more easily adjusted to the different and changing visual and non-visual needs of the professional staff, infants and family members throughout the 24-hour day. This paper provides a conceptual framework for defining good lighting in the NICU, recognizing the needs of various constituent groups, each with very different needs from the lighting. Several other papers on the topic of lighting for various constituent groups at different times of the day in the NICU are summarized. Attention is given specifically to the Recommended Standards for Newborn ICU Design, a consensus standard developed by a wide range of experts, to help the reader translate this conceptual framework to practice. PMID:28824339

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

NASA Astrophysics Data System (ADS)

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

Aviation signal lighting : impacts of lighting characteristics on visibility.

DOT National Transportation Integrated Search

2011-01-01

This paper summarizes research on visual responses to colored light signals in the aviation and : roadway environment and on government requirements for lighting along airfields. The objective : is to identify gaps in the knowledge about how individu...

Indoor Lighting Facilities

NASA Astrophysics Data System (ADS)

Matsushima, Koji; Saito, Yoshinori; Ichikawa, Shigenori; Kawauchi, Takao; Tanaka, Tsuneo; Hirano, Rika; Tazuke, Fuyuki

According to the statistics by the Ministry of Land, Infrastructure and Transport, the total floor space of all building construction started was 188.87 million m2 (1.5% increase y/y), marking the fourth straight year of increase. Many large-scale buildings under construction in central Tokyo become fully occupied by tenants before completion. As for office buildings, it is required to develop comfortable and functional office spaces as working styles are becoming more and more diversified, and lighting is also an element of such functionalities. The total floor space of construction started for exhibition pavilions, multipurpose halls, conference halls and religious architectures decreased 11.1% against the previous year. This marked a decline for 10 consecutive years and the downward trend continues. In exhibition pavilions, the light radiation is measured and adjusted throughout the year so as not to damage the artworks by lighting. Hospitals, while providing higher quality medical services and enhancing the dwelling environment of patients, are expected to meet various restrictions and requirements, including the respect for privacy. Meanwhile, lighting designs for school classrooms tend to be homogeneous, yet new ideas are being promoted to strike a balance between the economical and functional aspects. The severe economic environment continues to be hampering the growth of theaters and halls in both the private and public sectors. Contrary to the downsizing trend of such facilities, additional installations of lighting equipment were conspicuous, and the adoption of high efficacy lighting appliances and intelligent function control circuits are becoming popular. In the category of stores/commercial facilities, the construction of complex facilities is a continuing trend. Indirect lighting, high luminance discharge lamps with excellent color rendition and LEDs are being effectively used in these facilities, together with the introduction of lighting designs

Adaptation of light-harvesting functions of unicellular green algae to different light qualities.

PubMed

Ueno, Yoshifumi; Aikawa, Shimpei; Kondo, Akihiko; Akimoto, Seiji

2018-05-28

Oxygenic photosynthetic organisms perform photosynthesis efficiently by distributing captured light energy to photosystems (PSs) at an appropriate balance. Maintaining photosynthetic efficiency under changing light conditions requires modification of light-harvesting and energy-transfer processes. In the current study, we examined how green algae regulate their light-harvesting functions in response to different light qualities. We measured low-temperature time-resolved fluorescence spectra of unicellular green algae Chlamydomonas reinhardtii and Chlorella variabilis cells grown under different light qualities. By observing the delayed fluorescence spectra, we demonstrated that both types of green algae primarily modified the associations between light-harvesting chlorophyll protein complexes (LHCs) and PSs (PSII and PSI). Under blue light, Chlamydomonas transferred more energy from LHC to chlorophyll (Chl) located far from the PSII reaction center, while energy was transferred from LHC to PSI via different energy-transfer pathways in Chlorella. Under green light, both green algae exhibited enhanced energy transfer from LHCs to both PSs. Red light induced fluorescence quenching within PSs in Chlamydomonas and LHCs in Chlorella. In Chlorella, energy transfer from PSII to PSI appears to play an important role in balancing excitation between PSII and PSI.

Seeing the Light

ERIC Educational Resources Information Center

Sportel, Samuel; Bruxvoort, Crystal; Jadrich, James

2009-01-01

Conceptually, students are typically introduced to light as a type of wave. However, children struggle to understand this model because it is highly abstract. Light can be represented more concretely using the photon model. According to this scientific model, light emanates from sources as tiny "packets" of energy (called "photons") that move in…

Odontological light-emitting diode light-curing unit beam quality.

PubMed

de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira

2015-05-01

The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF = 1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF = 0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.

Odontological light-emitting diode light-curing unit beam quality

NASA Astrophysics Data System (ADS)

de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira

2015-05-01

The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF=1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF=0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.

System for diffusing light from an optical fiber or light guide

DOEpatents

Maitland, Duncan J [Pleasant Hill, CA; Wilson, Thomas S [San Leandro, CA; Benett, William J [Livermore, CA; Small, IV, Ward [

2008-06-10

A system for diffusing light from an optical fiber wherein the optical fiber is coupled to a light source, comprising forming a polymer element adapted to be connected to the optical fiber and incorporating a scattering element with the polymer element wherein the scattering element diffuses the light from the polymer element. The apparatus of the present invention comprises a polymer element operatively connected to the optical fiber and a scattering element operatively connected with the shape polymer element that diffuses the light from the polymer element.

Seeing the Light: The Roles of Red- and Blue-Light Sensing in Plant Microbes.

PubMed

Beattie, Gwyn A; Hatfield, Bridget M; Dong, Haili; McGrane, Regina S

2018-05-16

Plants collect, concentrate, and conduct light throughout their tissues, thus enhancing light availability to their resident microbes. This review explores the role of photosensing in the biology of plant-associated bacteria and fungi, including the molecular mechanisms of red-light sensing by phytochromes and blue-light sensing by LOV (light-oxygen-voltage)-domain proteins in these microbes. Bacteriophytochromes function as major drivers of the bacterial transcriptome and mediate light-regulated suppression of virulence, motility, and conjugation in some phytopathogens and light-regulated induction of the photosynthetic apparatus in a stem-nodulating symbiont. Bacterial LOV proteins also influence light-mediated changes in both symbiotic and pathogenic phenotypes. Although red-light sensing by fungal phytopathogens is poorly understood, fungal LOV proteins contribute to blue-light regulation of traits, including asexual development and virulence. Collectively, these studies highlight that plant microbes have evolved to exploit light cues and that light sensing is often coupled with sensing other environmental signals. Expected final online publication date for the Annual Review of Phytopathology Volume 56 is August 25, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Continuous background light significantly increases flashing-light enhancement of photosynthesis and growth of microalgae.

PubMed

Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

2015-01-01

Under specific conditions, flashing light enhances the photosynthesis rate in comparison to continuous illumination. Here we show that a combination of flashing light and continuous background light with the same integrated photon dose as continuous or flashing light alone can be used to significantly enhance photosynthesis and increase microalgae growth. To test this hypothesis, the green microalga Dunaliella salina was exposed to three different light regimes: continuous light, flashing light, and concomitant application of both. Algal growth was compared under three different integrated light quantities; low, intermediate, and moderately high. Under the combined light regime, there was a substantial increase in all algal growth parameters, with an enhanced photosynthesis rate, within 3days. Our strategy demonstrates a hitherto undescribed significant increase in photosynthesis and algal growth rates, which is beyond the increase by flashing light alone. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of light wavelength and coherence in structured light sensors

NASA Astrophysics Data System (ADS)

Harding, Kevin; Ramamurthy, Rajesh; Zhai, Zirong; Han, Jie; Yang, Dongmin

2016-05-01

Structured light methods are used by many commercial products on the market today. Many such systems using white light projectors while many line gages use standard red laser diodes. However, in recent years there has been much claimed about using blue light, polarized light and partially coherent systems to obtain better performance. Unlike interferometers, moving from red to blue light for a system using only geometric shape information does not gain an automatic advantage from the shorter wavelength. The sensitivity metric does not have a wavelength component to it. But there are other factors that can improve gage performance. The ability to measure some feature is also a function of other parameters such as signal to noise ratio, reflectivity variations, and depth-of-field over which a clear pattern can be seen. This paper will explore the theoretical and experimental data relating to what works and what can be expected from variations on the old methods.

The unbearable lightness of "light" cigarettes: a comparison of smoke yields in six varieties of Canadian "light" cigarettes.

PubMed

Gendreau, Paul L; Vitaro, Frank

2005-01-01

Labelling cigarettes as "light" or "mild" is claimed to be one of the biggest marketing scams in Canadian history. Arguably, such labelling implies that these varieties of cigarettes are less harmful than "regular" cigarettes. In Canada, a food product can be labelled "light" if there is a 25% reduction from the "reference food" and if the constituent being reduced is clearly identified (e.g., light in fat). Cigarette labelling does not comply with these regulations, however. To examine whether or not some tobacco constituents meet the 25% reduction criterion, we compared yields of 41 toxic and/or carcinogenic smoke constituents in six varieties of "light" cigarettes to the yields of "regular" cigarettes. We selected cigarettes from the two most popular Canadian brands, Du Maurier and Players. Using a set of data provided by Imperial Tobacco Canada and made available to the public by the Government of British Columbia, we compared yields measured under a laboratory protocol (modified ISO) that was designed to provide a more rigorous evaluation of the differences between varieties of cigarettes and a more accurate assessment of smokers' potential smoke intake than the traditional protocol (standard ISO). For all six varieties of "light" cigarettes, the yields of nicotine were higher by an average of 5% (range: 1% to 13%). The 25% reduction criterion was not met for any variety of "light" cigarettes concerning yields of tar. For all cigarettes tested, yields of tar were reduced on average by only 16% (range: 5% to 22%). For carbon monoxide (CO), only Player's Smooth Light had an over 25% reduction (30%) compared with Player's Regular. Conversely, yield of CO was 24% higher for Du Maurier Lights compared with Du Maurier Regular. As for the other smoke constituents, the majority (75%) were not reduced by 25% or more in "light" cigarettes, and a sizeable proportion of yields (e.g., acrylonitrile, benzene, chromium, m+p cresol, mercury, nickel, toluene) were larger in

Multiple night-time light-emitting diode lighting strategies impact grassland invertebrate assemblages.

PubMed

Davies, Thomas W; Bennie, Jonathan; Cruse, Dave; Blumgart, Dan; Inger, Richard; Gaston, Kevin J

2017-07-01

White light-emitting diodes (LEDs) are rapidly replacing conventional outdoor lighting technologies around the world. Despite rising concerns over their impact on the environment and human health, the flexibility of LEDs has been advocated as a means of mitigating the ecological impacts of globally widespread outdoor night-time lighting through spectral manipulation, dimming and switching lights off during periods of low demand. We conducted a three-year field experiment in which each of these lighting strategies was simulated in a previously artificial light naïve grassland ecosystem. White LEDs both increased the total abundance and changed the assemblage composition of adult spiders and beetles. Dimming LEDs by 50% or manipulating their spectra to reduce ecologically damaging wavelengths partially reduced the number of commoner species affected from seven to four. A combination of dimming by 50% and switching lights off between midnight and 04:00 am showed the most promise for reducing the ecological costs of LEDs, but the abundances of two otherwise common species were still affected. The environmental consequences of using alternative lighting technologies are increasingly well established. These results suggest that while management strategies using LEDs can be an effective means of reducing the number of taxa affected, averting the ecological impacts of night-time lighting may ultimately require avoiding its use altogether. © 2017 John Wiley & Sons Ltd.

Are Light and Ultra-Light Cigarettes Safer: Perceptions of College Students

ERIC Educational Resources Information Center

Zank, Gail M.; Smith, Karen H.; Stutts, Mary Ann

2008-01-01

The reported study investigates college students' perceptions of light compared to regular and ultra-light compared to light cigarettes, and whether perceptions vary by smoking status (nonsmoker, former smoker, social smoker, or regular smoker) and gender. A survey of 172 college students found that all four smoking status groups perceived light…

Homeostasis lighting control based on relationship between lighting environment and human behavior

NASA Astrophysics Data System (ADS)

Ueda, Risa; Mita, Akira

2015-03-01

Although each person has own preferences, living spaces which can respond to various preferences and needs have not become reality. Focusing on the lighting environments which influence on the impression of living spaces, this research aims to offer comfortable lighting environments for each resident by a flexible control. This research examines the relationship between lighting environments and human behaviors considering colored lights. In accord with the relationship, this research proposes an illuminance-color control system which flexibly changes spatial environments responding to human conditions. Firstly, the psychological evaluation was conducted in order to build human models for various environments. As a result, preferred lighting environments for each examinee were determined for particular behaviors. Moreover, satisfaction levels of lighting environments were calculated by using seven types of impression of the environments as parameters. The results were summarized as human models. Secondly, this research proposed "Homeostasis Lighting Control System", which employs the human models. Homeostasis lighting control system embodies the algorithm of homeostasis, which is one of the functions of the physiological adaptation. Human discomfort feelings are obtained automatically by the sensor agent robot. The system can offer comfortable lighting environments without controlling environments by residents autonomously based on the information from the robot. This research takes into accounts both illuminance and color. The robot communicates with the server which contains human models, then the system corresponds to individuals. Combining these three systems, the proposed system can effectively control the lighting environment. At last, the feasibility of the proposed system was verified by simulation experiments.

Natural light illumination system.

PubMed

Whang, Allen Jong-Woei; Chen, Yi-Yung; Yang, Shu-Hua; Pan, Po-Hsuan; Chou, Kao-Hsu; Lee, Yu-Chi; Lee, Zong-Yi; Chen, Chi-An; Chen, Cheng-Nan

2010-12-10

In recent years, green energy has undergone a lot of development and has been the subject of many applications. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting. Natural light illumination systems have collecting, transmitting, and lighting elements. Today, most daylight collectors use dynamic concentrators; these include Sun tracking systems. However, this design is too expensive to be cost effective. To create a low-cost collector that can be easily installed on a large building, we have designed a static concentrator, which is prismatic and cascadable, to collect sunlight for indoor illumination. The transmission component uses a large number of optical fibers. Because optical fibers are expensive, this means that most of the cost for the system will be related to transmission. In this paper, we also use a prismatic structure to design an optical coupler for coupling n to 1. With the n-to-1 coupler, the number of optical fibers necessary can be greatly reduced. Although this new natural light illumination system can effectively guide collected sunlight and send it to the basement or to other indoor places for healthy lighting, previously there has been no way to manage the collected sunlight when lighting was not desired. To solve this problem, we have designed an optical switch and a beam splitter to control and separate the transmitted light. When replacing traditional sources, the lighting should have similar characteristics, such as intensity distribution and geometric parameters, to those of traditional artificial sources. We have designed, simulated, and optimized an illumination lightpipe with a dot pattern to redistribute the collected sunlight from the natural light illumination system such that it equals the qualities of a traditional lighting system. We also provide an active lighting module that provides lighting from the natural light illumination system or LED auxiliary

Lighting in Commercial Buildings

EIA Publications

2009-01-01

Lighting is a major consumer of electricity in commercial buildings and a target for energy savings through use of energy-efficient light sources along with other advanced lighting technologies. The Commercial Buildings Energy Consumption Survey (CBECS) collects information on types of lighting equipment, the amount of floorspace that is lit, and the percentage of floorspace lit by each type. In addition, CBECS data are used to model end-use consumption, including energy consumed for lighting in commercial buildings.

Transfer Printing Method to Obtain Polarized Light Emission in Organic Light-Emitting Device

NASA Astrophysics Data System (ADS)

Noh, Hee Yeon; Park, Chang-sub; Park, Ji-Sub; Kang, Shin-Won; Kim, Hak-Rin

2012-06-01

We demonstrate a transfer printing method to obtain polarized light emission in organic light-emitting devices (OLEDs). On a rubbed self-assembled monolayer (SAM), a spin-coated liquid crystalline light-emissive polymer is aligned along the rubbing direction because of the anisotropic interfacial intermolecular interaction. Owing to the low surface energy of the SAM surface, the light-emissive layer was easily transferred to a patterned poly(dimethylsiloxane) (PDMS) stamp surface without degrading the ordering. Finally, a polarized light-emissive OLED device was prepared by transferring the patterned light-emissive layer to the charge transport layer of the OLED structure.

WRITING LIGHT VERSE.

ERIC Educational Resources Information Center

ARMOUR, RICHARD

VARIOUS ASPECTS OF WRITING LIGHT VERSE, EITHER FOR FUN OR FOR PUBLICATION, ARE DISCUSSED IN THIS BOOK--(1) THE NATURE AND APPEAL OF LIGHT VERSE AND ITS MANY VARIETIES, (2) SUBJECTS WHICH LEND THEMSELVES BEST TO THE LIGHT-VERSE TREATMENT, (3) THE APPLICATION OF WHAT ONE HAS LEARNED FROM READING, THINKING, AND CLOSELY OBSERVING HUMAN FOIBLES, (4)…

No-Light Light Bulbs

ERIC Educational Resources Information Center

Modern Schools, 1976

1976-01-01

A thumbnail sketch of some of the light bulbs manufactured for a purpose other than seeing. These "dark" lamps perform varied tasks including keeping food fresh, detecting and preventing disease, spurring plant growth, heating, and copying printed material. (Author/MLF)

NASA Lighting Research, Test, & Analysis

NASA Technical Reports Server (NTRS)

Clark, Toni

2015-01-01

The Habitability and Human Factors Branch, at Johnson Space Center, in Houston, TX, provides technical guidance for the development of spaceflight lighting requirements, verification of light system performance, analysis of integrated environmental lighting systems, and research of lighting-related human performance issues. The Habitability & Human Factors Lighting Team maintains two physical facilities that are integrated to provide support. The Lighting Environment Test Facility (LETF) provides a controlled darkroom environment for physical verification of lighting systems with photometric and spetrographic measurement systems. The Graphics Research & Analysis Facility (GRAF) maintains the capability for computer-based analysis of operational lighting environments. The combined capabilities of the Lighting Team at Johnson Space Center have been used for a wide range of lighting-related issues.

Light sheet microscopy reveals more gradual light attenuation in light green versus dark green soybean leaves

USDA-ARS?s Scientific Manuscript database

Light wavelengths preferentially absorbed by chlorophyll (chl) often display steep absorption gradients. This oversaturates photosynthesis in upper chloroplasts and deprives lower chloroplasts of blue and red light, causing a steep gradient in carbon fixation. Reducing chl content could create a mor...

Investigation of sodium arsenite, thioacetamide, and diethanolamine in the alkaline comet assay: Part of the JaCVAM comet validation exercise.

PubMed

Beevers, Carol; Henderson, Debbie; Lillford, Lucinda

2015-07-01

As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo rat alkaline comet assay (comet assay), we examined sodium arsenite, thioacetamide, and diethanolamine. Using the JaCVAM approved study protocol version 14.2, each chemical was tested in male rats up to maximum tolerated dose levels and DNA damage in the liver and stomach was assessed approximately 3h after the final administration by gavage. Histopathology assessments of liver and stomach sections from the same animals were also examined for evidence of cytotoxicity or necrosis. No evidence of DNA damage was observed in the stomach of animals treated with sodium arsenite at 7.5, 15, or 30 mg/kg/day. However, equivocal findings were found in the liver, where increases in DNA migration were observed in two independent experiments, but not in all treated animals and not at the same dose levels. Thioacetamide caused an increase in DNA migration in the stomach of rats treated at 19, 38, and 75 mg/kg/day, but not in the liver, despite evidence of marked hepatotoxicity following histopathology assessments. No evidence of DNA damage was observed in the stomach or liver of animals treated with diethanolamine at 175, 350, or 700 mg/kg/day. Copyright © 2015 Elsevier B.V. All rights reserved.

Stray Light Analysis

NASA Technical Reports Server (NTRS)

1997-01-01

Based on a Small Business Innovation Research contract from the Jet Propulsion Laboratory, TracePro is state-of-the-art interactive software created by Lambda Research Corporation to detect stray light in optical systems. An image can be ruined by incidental light in an optical system. To maintain image excellence from an optical system, stray light must be detected and eliminated. TracePro accounts for absorption, specular reflection and refraction, scattering and aperture diffraction of light. Output from the software consists of spatial irradiance plots and angular radiance plots. Results can be viewed as contour maps or as ray histories in tabular form. TracePro is adept at modeling solids such as lenses, baffles, light pipes, integrating spheres, non-imaging concentrators, and complete illumination systems. The firm's customer base includes Lockheed Martin, Samsung Electronics and other manufacturing, optical, aerospace, and educational companies worldwide.

Photonic crystal light source

DOEpatents

Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

2004-07-27

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Protein aggregation studied by forward light scattering and light transmission analysis

NASA Astrophysics Data System (ADS)

Penzkofer, A.; Shirdel, J.; Zirak, P.; Breitkreuz, H.; Wolf, E.

2007-12-01

The aggregation of the circadian blue-light photo-receptor cryptochrome from Drosophila melanogaster (dCry) is studied by transmission and forward light scattering measurement in the protein transparent wavelength region. The light scattering in forward direction is caused by Rayleigh scattering which is proportional to the degree of aggregation. The light transmission through the samples in the transparent region is reduced by Mie light scattering in all directions. It depends on the degree of aggregation and the monomer volume fill factor of the aggregates (less total scattering with decreasing monomer volume fill factor of protein globule) allowing a distinction between tightly packed protein aggregation (monomer volume fill factor 1) and loosely packed protein aggregation (monomer volume fill factor less than 1). An increase in aggregation with temperature, concentration, and blue-light exposure is observed. At a temperature of 4 °C and a protein concentration of less than 0.135 mM no dCry aggregation was observed, while at 24 °C and 0.327 mM gelation occurred (loosely packed aggregates occupying the whole solution volume).

Talking with Children about Light.

ERIC Educational Resources Information Center

Texas Child Care, 1996

1996-01-01

Suggests caregivers can help children learn about the concept of light using simple conversation and activities. Offers directions for activities in which children can consider the following questions about light: where does light come from?; can you see without light?; what blocks light?; how does light travel?; can you make a shadow?; and does…

Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise.

PubMed

Youngstedt, Shawn D; Kline, Christopher E; Elliott, Jeffrey A; Zielinski, Mark R; Devlin, Tina M; Moore, Teresa A

2016-02-26

Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210-2340 h, (2) treadmill exercise alone from 2210-2340 h, or (3) bright light (2210-2340 h) followed by exercise from 0410-0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect.

["The madhouse" by W. Kaulbach and the meaning of the picture interpreted by J.A. Schilling, 1863].

PubMed

Rothkopf, A

1980-01-01

This article deals with the picture "Das Narrenhaus" (the Madhouse) by W. Kaulbach and its interpretation by the psychiatrist J.A. Schilling, which he gave in his book "Psychiatrische Briefe" (psychiatric letters) in 1863. This picture is often used as a contemporary document for the situation in the treatment of the mentally ill at the beginning of the last century. The article points out doubts in this procedure. The interpretation by Schilling cannot be considered a document for psychiatric records; on the contrary, it is influenced by contemporary romantic medicine and utilises the picture to exemplify the theoretical concept of culpable human offence as the cause for mental illness.

Building Twilight "Light Sensors" to Study the Effects of Light Pollution on Fireflies

ERIC Educational Resources Information Center

Thancharoen, Anchana; Branham, Marc A.; Lloyd, James E.

2008-01-01

Light pollution negatively affects many nocturnal organisms. We outline two experiments that can be conducted by students to examine the effects of light pollution on firefly behavior. Inexpensive electronic light sensors, which are easy to construct and calibrate, are used to sample light levels along transects in spaces where fireflies are…

Roadmap on structured light

NASA Astrophysics Data System (ADS)

Rubinsztein-Dunlop, Halina; Forbes, Andrew; Berry, M. V.; Dennis, M. R.; Andrews, David L.; Mansuripur, Masud; Denz, Cornelia; Alpmann, Christina; Banzer, Peter; Bauer, Thomas; Karimi, Ebrahim; Marrucci, Lorenzo; Padgett, Miles; Ritsch-Marte, Monika; Litchinitser, Natalia M.; Bigelow, Nicholas P.; Rosales-Guzmán, C.; Belmonte, A.; Torres, J. P.; Neely, Tyler W.; Baker, Mark; Gordon, Reuven; Stilgoe, Alexander B.; Romero, Jacquiline; White, Andrew G.; Fickler, Robert; Willner, Alan E.; Xie, Guodong; McMorran, Benjamin; Weiner, Andrew M.

2017-01-01

Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized.

The Light-Emitting Diode as a Light Detector

ERIC Educational Resources Information Center

Baird, William H.; Hack, W. Nathan; Tran, Kiet; Vira, Zeeshan; Pickett, Matthew

2011-01-01

A light-emitting diode (LED) and operational amplifier can be used as an affordable method to provide a digital output indicating detection of an intense light source such as a laser beam or high-output LED. When coupled with a microcontroller, the combination can be used as a multiple photogate and timer for under $50. A similar circuit is used…

Light-emitting diode technology status and directions: Opportunities for horticultural lighting

DOE PAGES

Tsao, Jeffrey Y.; Pattison, P. Morgan; Krames, Michael R.

2016-01-01

Here, light-emitting diode (LED) technology has advanced rapidly over the last decade, primarily driven by display and general illumination applications ("solid-state lighting (SSL) for humans"). These advancements have made LED lighting technically and economically advantageous not only for these applications, but also, as an indirect benefit, for adjacent applications such as horticultural lighting ("SSL for plants"). Moreover, LED technology has much room for continued improvement. In the near-term, these improvements will continue to be driven by SSL for humans (with indirect benefit to SSL for plants), the most important of which can be anticipated.

Cauldron of Light

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Click on image to view the animation

In this animation, a seething cauldron of light appears to bubble and ooze around the remains of a giant star that astronomers have been watching tear itself apart for the last 300 years. This movie flips quickly between different observations taken over three years by NASA's Spitzer Space Telescope.

Beginning in the center, the well-studied Cassiopeia A supernova remnant is shown. Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died.

Panning outward, 'light echoes' create the illusion of motion in the clouds, as different areas of the material are lit up in succession by the light flash of the supernova. A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light.

In reality, the clouds are stationary, at least in the brief time over which these observations were taken. The inclination of the clouds cause some light echoes to appear to expand away from the supernova remnant, while others move towards it or boil in many directions with seeming turbulence.

Risk of malnutrition (over and under-nutrition): validation of the JaNuS screening tool.

PubMed

Donini, Lorenzo M; Ricciardi, Laura Maria; Neri, Barbara; Lenzi, Andrea; Marchesini, Giulio

2014-12-01

Malnutrition (over and under-nutrition) is highly prevalent in patients admitted to hospital and it is a well-known risk factor for increased morbidity and mortality. Nutritional problems are often misdiagnosed, and especially the coexistence of over and undernutrition is not usually recognized. We aimed to develop and validate a screening tool for the easy detection and reporting of both undernutrition and overnutrition, specifically identifying the clinical conditions where the two types of malnutrition coexist. The study consisted of three phases: 1) selection of an appropriate study population (estimation sample) and of the hospital admission parameters to identify overnutrition and undernutrition; 2) combination of selected variables to create a screening tool to assess the nutritional risk in case of undernutrition, overnutrition, or the copresence of both the conditions, to be used by non-specialist health care professionals; 3) validation of the screening tool in a different patient sample (validation sample). Two groups of variables (12 for undernutrition, 7 for overnutrition) were identified in separate logistic models for their correlation with the outcome variables. Both models showed high efficacy, sensitivity and specificity (overnutrition, 97.7%, 99.6%, 66.6%, respectively; undernutrition, 84.4%, 83.6%, 84.8%). The logistic models were used to construct a two-faced test (named JaNuS - Just A Nutritional Screening) fitting into a two-dimension Cartesian coordinate graphic system. In the validation sample the JaNuS test confirmed its predictive value. Internal consistency and test-retest analysis provide evidence for the reliability of the test. The study provides a screening tool for the assessment of the nutritional risk, based on parameters easy-to-use by health care personnel lacking nutritional competence and characterized by excellent predictive validity. The test might be confidently applied in the clinical setting to determine the importance of

Berkeley Lighting Cone

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

Lask, Kathleen; Gadgil, Ashok

A lighting cone is a simple metal cone placed on the fuel bed of a stove during ignition to act as a chimney, increasing the draft through the fuel bed. Many stoves tend to be difficult to light due to poor draft through the fuel bed, so lighting cones are used in various parts of the world as an inexpensive accessory to help with ignition.

Effect of laser speckle on light from laser diode-pumped phosphor-converted light sources.

PubMed

Aquino, Felipe; Jadwisienczak, Wojciech M; Rahman, Faiz

2017-01-10

Laser diode (LD) pumped white light sources are being developed as an alternative to light-emitting diode-pumped sources for high efficiency and/or high brightness applications. While several performance metrics of laser-pumped phosphor-converted light sources have been investigated, the effect of laser speckle has not been sufficiently explored. This paper describes our experimental studies on how laser speckle affects the behavior of light from laser-excited phosphor lamps. A single LD pumping a phosphor plate was the geometry explored in this work. Overall, our findings are that the down-converted light did not exhibit any speckle, whereas speckle was present in the residual pump light but much reduced from that in direct laser light. Furthermore, a thicker coating of small-grained phosphors served to effectively reduce speckle through static pump light diffusion in the phosphor coating. Our investigations showed that speckle is not of concern in illumination from LD-pumped phosphor-converted light sources.

Dark Skies Preservation through Responsible Lighting: the IYL2015 Quality Lighting Kit

NASA Astrophysics Data System (ADS)

Walker, Constance E.

2015-01-01

Poor quality lighting not only impedes astronomy research, but creates safety issues, affects human circadian sensitivities, disrupts ecosystems, and wastes more than a few billion dollars/year of energy in the USA alone. The United Nations-sanctioned the International Year of Light in 2015 (IYL2015) is providing an opportunity to increase public awareness of dark skies preservation, quality lighting and energy conservation. The Education and Public Outreach (EPO) group at the National Optical Astronomy Observatory (NOAO) has received a small grant through the International Astronomical Union (IAU) to produce official 'Quality Lighting Teaching Kits' for the IYL2015 cornerstone theme, 'Cosmic Light'. These kits will emphasize the use of proper optical design in achieving quality lighting that promotes both energy efficiency and energy conservation of an endangered natural resource, our dark skies. The concepts and practice of 'quality lighting' will be explored through demonstrations, hands-on/minds-on activities, formative assessment probes, and engineering design projects that explore basic principles of optics and the physics of light. The impact of the kits will be amplified by providing professional development using tutorial videos created at NOAO and conducting question and answer sessions via Google+ Hangouts for the outreach volunteers. The quality lighting education program will leverage NOAO EPO's work in the last ten years on lighting and optics education (e.g., the IAU 'Dark Skies Africa', APS 'Dark Skies Yuma' and 'Hands-On Optics' programs). NOAO's partners are CIE (International Commission on Illumination), IDA (International Dark-Sky Association) and SPIE (International Society for Optics and Photonics), as well as the IAU Office of Astronomy for Development, Galileo Teacher Training Program, Universe Awareness, and Global Hands-on Universe. Their networks will disseminate the program and kits to formal and informal audiences worldwide. The impact

Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise

PubMed Central

Kline, Christopher E.; Elliott, Jeffrey A.; Zielinski, Mark R.; Devlin, Tina M.; Moore, Teresa A.

2016-01-01

Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210–2340 h, (2) treadmill exercise alone from 2210–2340 h, or (3) bright light (2210–2340 h) followed by exercise from 0410–0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect. PMID:27103935

Effects of different light intensities in the morning on dim light melatonin onset.

PubMed

Kozaki, Tomoaki; Toda, Naohiro; Noguchi, Hiroki; Yasukouchi, Akira

2011-01-01

The present study evaluated the effects of exposure to light intensity in the morning on dim light melatonin onset (DLMO). The tested light intensities were 750 lux, 150 lux, 3000 lux, 6000 lux and 12,000 lux (horizontal illuminance at cornea), using commercial 5000 K fluorescent lamps. Eleven healthy males aged 21-31 participated in 2-day experiments for each light condition. On the first experimental day (day 1), subjects were exposed to dim light (<30 lux) for 3 h in the morning (09:00-12:00). On the same day, saliva samples were taken in dim light (<30 lux) every 30 min from 21:00 to 01:00 to determine the DLMO phase. The subjects were allowed to sleep from 01:00 to 08:00. On the second experimental day (day 2), the subjects were exposed to experimental light conditions for 3 h in the morning. The experimental schedule after light exposure was the same as on day 1. On comparing day 2 with day 1, significant phase advances of DLMO were obtained at 3000 lux, 6000 lux and 12,000 lux. These findings indicate that exposure to a necessary intensity from an ordinary light source, such as a fluorescent lamp, in the morning within one day affects melatonin secretion.

LED lighting increases the ecological impact of light pollution irrespective of color temperature.

PubMed

Pawson, S M; Bader, M K-F

Recognition of the extent and magnitude of night-time light pollution impacts on natural ecosystems is increasing, with pervasive effects observed in both nocturnal and diurnal species. Municipal and industrial lighting is on the cusp of a step change where energy-efficient lighting technology is driving a shift from “yellow” high-pressure sodium vapor lamps (HPS) to new “white” light-emitting diodes (LEDs). We hypothesized that white LEDs would be more attractive and thus have greater ecological impacts than HPS due to the peak UV-green-blue visual sensitivity of nocturnal invertebrates. Our results support this hypothesis; on average LED light traps captured 48% more insects than were captured with light traps fitted with HPS lamps, and this effect was dependent on air temperature (significant light × air temperature interaction). We found no evidence that manipulating the color temperature of white LEDs would minimize the ecological impacts of the adoption of white LED lights. As such, large-scale adoption of energy-efficient white LED lighting for municipal and industrial use may exacerbate ecological impacts and potentially amplify phytosanitary pest infestations. Our findings highlight the urgent need for collaborative research between ecologists and electrical engineers to ensure that future developments in LED technology minimize their potential ecological effects.

Leveraging brightness from transportation lighting systems through light source color.

DOT National Transportation Integrated Search

2013-11-01

Roadway transportation lighting is installed for multiple reasons including traffic safety and pedestrian : security. Judgments of pedestrian safety and security along roadways are not strictly correlated to : specified light levels, but the color of...

40 CFR Appendix Xviii to Part 86 - Statistical Outlier Identification Procedure for Light-Duty Vehicles and Light Light-Duty Trucks...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Statistical Outlier Identification Procedure for Light-Duty Vehicles and Light Light-Duty Trucks Certifying to the Provisions of Part 86... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES...

40 CFR Appendix Xviii to Part 86 - Statistical Outlier Identification Procedure for Light-Duty Vehicles and Light Light-Duty Trucks...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Statistical Outlier Identification Procedure for Light-Duty Vehicles and Light Light-Duty Trucks Certifying to the Provisions of Part 86... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES...

Light-emitting diodes (LED) for domestic lighting: any risks for the eye?

PubMed

Behar-Cohen, F; Martinsons, C; Viénot, F; Zissis, G; Barlier-Salsi, A; Cesarini, J P; Enouf, O; Garcia, M; Picaud, S; Attia, D

2011-07-01

Light-emitting diodes (LEDs) are taking an increasing place in the market of domestic lighting because they produce light with low energy consumption. In the EU, by 2016, no traditional incandescent light sources will be available and LEDs may become the major domestic light sources. Due to specific spectral and energetic characteristics of white LEDs as compared to other domestic light sources, some concerns have been raised regarding their safety for human health and particularly potential harmful risks for the eye. To conduct a health risk assessment on systems using LEDs, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), a public body reporting to the French Ministers for ecology, for health and for employment, has organized a task group. This group consisted physicists, lighting and metrology specialists, retinal biologist and ophthalmologist who have worked together for a year. Part of this work has comprised the evaluation of group risks of different white LEDs commercialized on the French market, according to the standards and found that some of these lights belonged to the group risk 1 or 2. This paper gives a comprehensive analysis of the potential risks of white LEDs, taking into account pre-clinical knowledge as well as epidemiologic studies and reports the French Agency's recommendations to avoid potential retinal hazards. Copyright © 2011. Published by Elsevier Ltd.

Green-light supplementation for enhanced lettuce growth under red- and blue-light-emitting diodes

NASA Technical Reports Server (NTRS)

Kim, Hyeon-Hye; Goins, Gregory D.; Wheeler, Raymond M.; Sager, John C.

2004-01-01

Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.

Dissecting a Light Echo

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Click on image for audio animation

This animation illustrates how a light echo works, and how an optical illusion of material moving outward is created.

A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one.

The animation starts by showing the explosion of a star, which results in a flash of light that moves outward in all directions. The direction of our line of sight from Earth is indicated by the blue arrow.

When the light flash reaches surrounding dust, shown here as three dark clouds, the dust is heated up, creating infrared light that begins to travel toward Earth (indicated by the red arrows). Dust closest to the explosion lights up first, while the explosion's shock wave takes longer to reach more distant material. This results in light from different parts of the cloud reaching Earth at different times, creating the illusion of motion over time.

As the animation shows, the inclination of the cloud toward our line of sight can result in the material seeming to move both away from and toward the central star.

Light Redirective Display Panel And A Method Of Making A Light Redirective Display Panel

DOEpatents

Veligdan, James T.

2005-07-26

An optical display panel which provides improved light intensity at a viewing angle by redirecting light emitting from the viewing screen, and a method of making a light redirective display panel, are disclosed. The panel includes an inlet face at one end for receiving light, and an outlet screen at an opposite end for displaying the light. The inlet face is defined at one end of a transparent body, which body may be formed by a plurality of waveguides, and the outlet screen is defined at an opposite end of the body. The screen includes light redirective elements at the outlet screen for re-directing light emitting from the outlet screen. The method includes stacking a plurality of glass sheets, with a layer of adhesive or epoxy between each sheet, curing the adhesive to form a stack, placing the stack against a saw and cutting the stack at two opposite ends to form a wedge-shaped panel having an inlet face and an outlet face, and forming at the outlet face a plurality of light redirective elements which direct light incident on the outlet face into a controlled light cone.

Light redirective display panel and a method of making a light redirective display panel

DOEpatents

Veligdan, James T.

2002-01-01

An optical display panel which provides improved light intensity at a viewing angle by redirecting light emitting from the viewing screen, and a method of making a light redirective display panel, are disclosed. The panel includes an inlet face at one end for receiving light, and an outlet screen at an opposite end for displaying the light. The inlet face is defined at one end of a transparent body, which body may be formed by a plurality of waveguides, and the outlet screen is defined at an opposite end of the body. The screen includes light redirective elements at the outlet screen for re-directing light emitting from the outlet screen. The method includes stacking a plurality of glass sheets, with a layer of adhesive or epoxy between each sheet, curing the adhesive to form a stack, placing the stack against a saw and cutting the stack at two opposite ends to form a wedge-shaped panel having an inlet face and an outlet face, and forming at the outlet face a plurality of light redirective elements which direct light incident on the outlet face into a controlled light cone.

Light Emitting Diodes (LEDs)

NASA Technical Reports Server (NTRS)

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.

Indoor visible light communication with smart lighting technology

NASA Astrophysics Data System (ADS)

Das Barman, Abhirup; Halder, Alak

2017-02-01

An indoor visible-light communication performance is investigated utilizing energy efficient white light by 2D LED arrays. Enabled by recent advances in LED technology, IEEE 802.15.7 standardizes high-data-rate visible light communication and advocates for colour shift keying (CSK) modulation to overcome flicker and to support dimming. Voronoi segmentation is employed for decoding N-CSK constellation which has superior performance compared to other existing decoding methods. The two chief performance degrading effects of inter-symbol interference and LED nonlinearity is jointly mitigated using LMS post equalization at the receiver which improves the symbol error rate performance and increases field of view of the receiver. It is found that LMS post equalization symbol at 250MHz offers 7dB SNR improvement at SER10-6

Low-energy light bulbs, computers, tablets and the blue light hazard.

PubMed

O'Hagan, J B; Khazova, M; Price, L L A

2016-02-01

The introduction of low energy lighting and the widespread use of computer and mobile technologies have changed the exposure of human eyes to light. Occasional claims that the light sources with emissions containing blue light may cause eye damage raise concerns in the media. The aim of the study was to determine if it was appropriate to issue advice on the public health concerns. A number of sources were assessed and the exposure conditions were compared with international exposure limits, and the exposure likely to be received from staring at a blue sky. None of the sources assessed approached the exposure limits, even for extended viewing times.

Low-energy light bulbs, computers, tablets and the blue light hazard

PubMed Central

O'Hagan, J B; Khazova, M; Price, L L A

2016-01-01

The introduction of low energy lighting and the widespread use of computer and mobile technologies have changed the exposure of human eyes to light. Occasional claims that the light sources with emissions containing blue light may cause eye damage raise concerns in the media. The aim of the study was to determine if it was appropriate to issue advice on the public health concerns. A number of sources were assessed and the exposure conditions were compared with international exposure limits, and the exposure likely to be received from staring at a blue sky. None of the sources assessed approached the exposure limits, even for extended viewing times. PMID:26768920

13. INTERIOR OF LIVING ROOM SHOWING 2LIGHT OVER 2LIGHT, DOUBLEHUNG, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. INTERIOR OF LIVING ROOM SHOWING 2-LIGHT OVER 2-LIGHT, DOUBLE-HUNG, WOOD-FRAMED WINDOWS ON SOUTHEAST WALL, AND UNUSUAL 1-LIGHT SASH WINDOW WITH TRANSOM AT PHOTO LEFT. VIEW TO SOUTHEAST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

FACILITY 72, INTERIOR. 15LIGHT DOUBLE DOORS WITH 15LIGHT SIDELIGHTS AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FACILITY 72, INTERIOR. 15-LIGHT DOUBLE DOORS WITH 15-LIGHT SIDELIGHTS AND 2-LIGHT TRANSOM. LIVING ROOM BEYOND. VIEW FACING NORTH-NORTHEAST. - U.S. Naval Base, Pearl Harbor, Naval Housing Area Makalapa, Senior Officers' Quarters Type C, North end of Makalapa Drive, Pearl City, Honolulu County, HI

Ocular forward light scattering and corneal backward light scattering in patients with dry eye.

PubMed

Koh, Shizuka; Maeda, Naoyuki; Ikeda, Chikako; Asonuma, Sanae; Mitamura, Hayato; Oie, Yoshinori; Soma, Takeshi; Tsujikawa, Motokazu; Kawasaki, Satoshi; Nishida, Kohji

2014-09-18

To evaluate ocular forward light scattering and corneal backward light scattering in patients with dry eye. Thirty-five eyes in 35 patients with dry eye and 20 eyes of 20 healthy control subjects were enrolled. The 35 dry eyes were classified into two groups according to whether superficial punctate keratopathy in the central 6-mm corneal zone (cSPK) was present or not. Ocular forward light scattering was quantified with a straylight meter. Corneal backward light scattering from the anterior, middle, and posterior corneal parts was assessed with a corneal densitometry program using the Scheimpflug imaging system. Both dry eye groups had significantly higher intraocular forward light scattering than the control group (both P<0.05). The dry eye group with cSPK had significantly higher values in anterior and total corneal backward light scattering than the other two groups. Moderate positive correlations were observed between the cSPK score and corneal backward light scattering from the anterior cornea (R=0.60, P<0.001) and corneal backward light scattering from the total cornea (R=0.54, P<0.001); however, no correlation was found between cSPK score and ocular forward light scattering (R=0.01, P=0.932). Ocular forward light scattering and corneal backward light scattering from the anterior cornea were greater in dry eyes than in normal eyes. Increased corneal backward light scattering in dry eye at least partially results from cSPK overlying the optical zone. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Response of bats to light with different spectra: light-shy and agile bat presence is affected by white and green, but not red light

PubMed Central

van Grunsven, Roy H. A.; Ramakers, Jip J. C.; Ferguson, Kim B.; Raap, Thomas; Donners, Maurice; Veenendaal, Elmar M.; Visser, Marcel E.

2017-01-01

Artificial light at night has shown a remarkable increase over the past decades. Effects are reported for many species groups, and include changes in presence, behaviour, physiology and life-history traits. Among these, bats are strongly affected, and how bat species react to light is likely to vary with light colour. Different spectra may therefore be applied to reduce negative impacts. We used a unique set-up of eight field sites to study the response of bats to three different experimental light spectra in an otherwise dark and undisturbed natural habitat. We measured activity of three bat species groups around transects with light posts emitting white, green and red light with an intensity commonly used to illuminate countryside roads. The results reveal a strong and spectrum-dependent response for the slow-flying Myotis and Plecotus and more agile Pipistrellus species, but not for Nyctalus and Eptesicus species. Plecotus and Myotis species avoided white and green light, but were equally abundant in red light and darkness. The agile, opportunistically feeding Pipistrellus species were significantly more abundant around white and green light, most likely because of accumulation of insects, but equally abundant in red illuminated transects compared to dark control. Forest-dwelling Myotis and Plecotus species and more synanthropic Pipistrellus species are thus least disturbed by red light. Hence, in order to limit the negative impact of light at night on bats, white and green light should be avoided in or close to natural habitat, but red lights may be used if illumination is needed. PMID:28566484

Response of bats to light with different spectra: light-shy and agile bat presence is affected by white and green, but not red light.

PubMed

Spoelstra, Kamiel; van Grunsven, Roy H A; Ramakers, Jip J C; Ferguson, Kim B; Raap, Thomas; Donners, Maurice; Veenendaal, Elmar M; Visser, Marcel E

2017-05-31

Artificial light at night has shown a remarkable increase over the past decades. Effects are reported for many species groups, and include changes in presence, behaviour, physiology and life-history traits. Among these, bats are strongly affected, and how bat species react to light is likely to vary with light colour. Different spectra may therefore be applied to reduce negative impacts. We used a unique set-up of eight field sites to study the response of bats to three different experimental light spectra in an otherwise dark and undisturbed natural habitat. We measured activity of three bat species groups around transects with light posts emitting white, green and red light with an intensity commonly used to illuminate countryside roads. The results reveal a strong and spectrum-dependent response for the slow-flying Myotis and Plecotus and more agile Pipistrellus species, but not for Nyctalus and Eptesicus species. Plecotus and Myotis species avoided white and green light, but were equally abundant in red light and darkness. The agile, opportunistically feeding Pipistrellus species were significantly more abundant around white and green light, most likely because of accumulation of insects, but equally abundant in red illuminated transects compared to dark control. Forest-dwelling Myotis and Plecotus species and more synanthropic Pipistrellus species are thus least disturbed by red light. Hence, in order to limit the negative impact of light at night on bats, white and green light should be avoided in or close to natural habitat, but red lights may be used if illumination is needed. © 2017 The Author(s).

Lighting: Traffic Safety Tips

DOT National Transportation Integrated Search

1996-01-01

This fact sheet, NHTSA Facts: Summer 1996, discusses traffic safety tips on motor vehicle lighting, including headlights, tail lights, and signal lights. It details the cleaning of headlamps, proper aiming of headlamps, and replacement of burned out ...

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

PubMed Central

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 oxygen species (ROS) production, altered the protein expression level, induced the aggregation of short-wavelength opsins (S-opsin), resulting in severe cell damage. While, blue LED light damaged the primary retinal cells and the damage was photoreceptor specific. N-Acetylcysteine (NAC), an antioxidant, protected against the cellular damage induced by blue LED light. Overall, the LED light induced cell damage was wavelength-, but not energy-dependent and may cause more severe retinal photoreceptor cell damage than the other LED light. PMID:24909301

Light reflecting apparatus including a multi-aberration light reflecting surface

DOEpatents

Sawicki, Richard H.; Sweatt, William

1987-01-01

A light reflecting apparatus including a multi-aberration bendable light reflecting surface is disclosed herein. This apparatus includes a structural assembly comprised of a rectangular plate which is resiliently bendable, to a limited extent, and which has a front side defining the multi-aberration light reflecting surface and an opposite back side, and a plurality of straight leg members rigidly connected with the back side of the plate and extending rearwardly therefrom. The apparatus also includes a number of different adjustment mechanisms, each of which is connected with specific ones of the leg members. These mechanisms are adjustably movable in different ways for applying corresponding forces to the leg members in order to bend the rectangular plate and light reflecting surface into different predetermined curvatures and which specifically include quadratic and cubic curvatures corresponding to different optical aberrations.

Effect of 670-nm Light-Emitting Diode Light On Neuronal Cultures

NASA Technical Reports Server (NTRS)

Wong-Riley, Margaret T. T.; Whelan, Harry T.

2002-01-01

Light close to and within the near infrared range has documented benefits for promoting wound healing in human and animal studies. Our preliminary results using light-emitting diodes (LEDs) in this range have also demonstrated two-to five-fold increases in growth-phase-specific DNA synthesis in normal fibroblasts, muscle cells, osteoblasts, and mucosal epithelial cells in tissue cultures. However, the mechanisms of action of such light on cells are poorly understood. We hypothesized that the therapeutic effects of such light result from the stimulation of cellular events associated with increases in cytochrome oxidase activity. As a first step in testing our hypothesis, we subjected primary neuronal cultures to impulse blockade by tetrodotoxin (TTX), a voltage-dependent sodium channel blocker, and applied LED light at 670 nm to determine if it could partially or fully reverse the reduction of cytochrome oxidase activity by TTX. The wavelength and parameters were previously tested to be beneficial for wound healing.

Progress in wet-coated organic light-emitting devices for lighting

NASA Astrophysics Data System (ADS)

Liu, Jie; Ye, Qing; Lewis, Larry N.; Duggal, Anil R.

2007-09-01

Here we present recent progress in developing efficient wet-coated organic light-emitting devices (OLEDs) for lighting applications. In particular, we describe a novel approach for building efficient wet-coated dye-doped blue phosphorescent devices. Further, a novel approach for achieving arbitrary emission patterning for OLEDs is discussed. This approach utilizes a photo-induced chemical doping strategy for selectively activating charge injection materials, thus enabling devices with arbitrary emission patterning. This approach may provide a simple, low cost path towards specialty lighting and signage applications for OLED technology.

30. BEDROOM #3 INTERIOR SHOWING 1 LIGHT OVER 1 LIGHT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. BEDROOM #3 INTERIOR SHOWING 1 LIGHT OVER 1 LIGHT WINDOW ON EAST WALL AND PARTIALLY OPENED DOOR TO WINDOWED CLOSET. VIEW TO EAST. - Big Creek Hydroelectric System, Powerhouse 8, Operator Cottage, Big Creek, Big Creek, Fresno County, CA

Pulsed-light imaging for fluorescence guided surgery under normal room lighting.

PubMed

Sexton, Kristian; Davis, Scott C; McClatchy, David; Valdes, Pablo A; Kanick, Stephen C; Paulsen, Keith D; Roberts, David W; Pogue, Brian W

2013-09-01

Fluorescence guided surgery (FGS) is an emerging technology that has demonstrated improved surgical outcomes. However, dim lighting conditions required by current FGS systems are disruptive to standard surgical workflow. We present a novel FGS system capable of imaging fluorescence under normal room light by using pulsed excitation and gated acquisition. Images from tissue-simulating phantoms confirm visual detection down to 0.25 μM of protoporphyrin IX under 125 μW/cm2 of ambient light, more than an order of magnitude lower than that measured with the Zeiss Pentero in the dark. Resection of orthotopic brain tumors in mice also suggests that the pulsed-light system provides superior sensitivity in vivo.

Fingerprints in the Light

NASA Image and Video Library

2005-03-01

This spectrum shows the light from a dusty, distant galaxy located 11 billion light-years away. The galaxy is invisible to optical telescopes, but NASA Spitzer Space Telescope captured the light from it and dozens of other similar galaxies.

Shining a Light on Electronics

ERIC Educational Resources Information Center

Statler, James D.

2009-01-01

While they produced a limited amount of light when first introduced, light-emitting diode (LED) lights offered the benefit of rarely burning out. As a result, they were initially used primarily as indicator lights. Advances in the technology have made available LEDs that produce far brighter light, and one application that has come to market is…

Effect of inhomogeneity of light from light curing units on the surface hardness of composite resin.

PubMed

Arikawa, Hiroyuki; Kanie, Takahito; Fujii, Koichi; Takahashi, Hideo; Ban, Seiji

2008-01-01

This study investigated the characteristics of output light from different types of light curing units, and their effects on polymerization of light-activated composite resin. Three quartz-tungsten-halogen lamps, one plasma arc lamp, and one LED light curing unit were used. Intensity distribution of light emitted from the light guide tip was measured at 1.0-mm intervals across the guide tip. Distribution of Knoop hardness number on the surface of resin irradiated with the light curing units was also measured. For all units, inhomogeneous distribution of light intensity across the guide tip was observed. Minimum light intensity values were 19-80% of the maximum values. In terms of surface hardness, inhomogeneous distribution was also observed for the materials irradiated with the tested units. Minimum values were 53-92% of the maximum values. Our results indicated that markedly inhomogeneous light emitted from light curing unit could result in inhomogeneous polymerization in some areas of the restoration below the light guide tip.

Light diffusing fiber optic chamber

DOEpatents

Maitland, Duncan J.

2002-01-01

A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

Light Pollution and Wildlife

NASA Astrophysics Data System (ADS)

Duffek, J.

2008-12-01

for Educational Program IYA Dark Skies Education Session Fall American Geophysical Union San Francisco, December 15-19, 2008 Light Pollution and Wildlife This is a very exciting time to be a part of the mission to keep the nighttime skies natural. The International Year of Astronomy (IYA) 2009 is developing programs for all areas of Dark Skies Awareness. For many years the issue of light pollution focused on the impact to the astronomy industry. While this is an important area, research has shown that light pollution negatively impacts wildlife, their habitat, human health, and is a significant waste of energy. Since the message and impact of the effects of light pollution are much broader now, the message conveyed to the public must also be broader. Education programs directed at youth are a new frontier to reach out to a new audience about the adverse effects of too much artificial light at night. The International Dark-Sky Association (IDA) has developed educational presentations using the National Science Teachers Association Education Standards. These programs focus on youth between the ages of 5 to 17exploring new territory in the education of light pollution. The IDA education programs are broken down into three age groups; ages 5-9, 8-13, 12 and older. The presentations come complete with PowerPoint slides, discussion notes for each slide, and workbooks including age appropriate games to keep young audiences involved. A new presentation reflects the growing area of interest regarding the effects of too much artificial light at night on wildlife. This presentation outlines the known problems for ecosystems caused by artificial light at night. Insects are attracted to artificial lights and may stay near that light all night. This attraction interferes with their ability to migrate, mate, and look for food. Such behavior leads to smaller insect populations. Fewer insects in turn affect birds and bats, because they rely on insects as a food source. The IDA

Inorganic volumetric light source excited by ultraviolet light

DOEpatents

Reed, Scott; Walko, Robert J.; Ashley, Carol S.; Brinker, C. Jeffrey

1994-01-01

The invention relates to a composition for the volumetric generation of radiation. The composition comprises a porous substrate loaded with a component capable of emitting radiation upon interaction with an exciting radiation. Preferably, the composition is an aerogel substrate loaded with a component, e.g., a phosphor, capable of interacting with exciting radiation of a first energy, e.g., ultraviolet light, to produce radiation of a second energy, e.g., visible light.

Inorganic volumetric light source excited by ultraviolet light

DOEpatents

Reed, S.; Walko, R.J.; Ashley, C.S.; Brinker, C.J.

1994-04-26

The invention relates to a composition for the volumetric generation of radiation. The composition comprises a porous substrate loaded with a component capable of emitting radiation upon interaction with an exciting radiation. Preferably, the composition is an aerogel substrate loaded with a component, e.g., a phosphor, capable of interacting with exciting radiation of a first energy, e.g., ultraviolet light, to produce radiation of a second energy, e.g., visible light. 4 figures.

Effects of day-time exposure to different light intensities on light-induced melatonin suppression at night.

PubMed

Kozaki, Tomoaki; Kubokawa, Ayaka; Taketomi, Ryunosuke; Hatae, Keisuke

2015-07-04

Bright nocturnal light has been known to suppress melatonin secretion. However, bright light exposure during the day-time might reduce light-induced melatonin suppression (LIMS) at night. The effective proportion of day-time light to night-time light is unclear; however, only a few studies on accurately controlling both day- and night-time conditions have been conducted. This study aims to evaluate the effect of different day-time light intensities on LIMS. Twelve male subjects between the ages of 19 and 23 years (mean ± S.D., 20.8 ± 1.1) gave informed consent to participate in this study. They were exposed to various light conditions (<10, 100, 300, 900 and 2700 lx) between the hours of 09:00 and 12:00 (day-time light conditions). They were then exposed to bright light (300 lx) again between 01:00 and 02:30 (night-time light exposure). They provided saliva samples before (00:55) and after night-time light exposure (02:30). A one-tailed paired t test yielded significant decrements of melatonin concentration after night-time light exposure under day-time dim, 100- and 300-lx light conditions. No significant differences exist in melatonin concentration between pre- and post-night-time light exposure under day-time 900- and 2700-lx light conditions. Present findings suggest the amount of light exposure needed to prevent LIMS caused by ordinary nocturnal light in individuals who have a general life rhythm (sleep/wake schedule). These findings may be useful in implementing artificial light environments for humans in, for example, hospitals and underground shopping malls.

Light scattering and light transmittance of cadaver eye-explanted intraocular lenses of different materials.

PubMed

Morris, Caleb; Werner, Liliana; Barra, Daniel; Liu, Erica; Stallings, Shannon; Floyd, Anne

2014-01-01

To evaluate light scattering and light transmittance in cadaver eye-explanted intraocular lenses (IOLs) manufactured from different materials. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Forty-nine pseudophakic cadaver eyes were selected according to IOL material/type and implantation duration, and the IOLs were explanted. Hydrophobic acrylic, hydrophilic acrylic, poly(methyl methacrylate) (PMMA), and silicone IOLs were included. Gross and light microscopy was performed for all IOLs. Light scattering was measured with an EAS 1000 Scheimpflug camera, and light transmittance was assessed using a Lambda 35 UV/Vis spectrophotometer (single-beam configuration with an RSA PE-20 integrating sphere). Analyses were performed at room temperature in the hydrated state and compared with analyses of controls. The highest levels of surface light scattering were measured for 3-piece hydrophobic acrylic, which was also the IOL type with the longest implantation duration among the Acrysof hydrophobic acrylic IOLs. Hydrophilic acrylic, PMMA, and silicone IOLs exhibited relatively low light-scattering levels. The lowest light-scattering levels were observed with PMMA IOLs (1-piece looped and 3-piece) and plate silicone IOLs, which represent the IOL types with the longest implantation duration in this series. Light transmittance values measured for all IOL types appeared to be similar to the values of the corresponding control IOLs. The phenomenon of surface light scattering (nanoglistenings) is more particularly related to hydrophobic acrylic IOLs and increases with implantation time. No significant effect of surface light scattering on IOL light transmittance was found. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Advanced lighting guidelines: 1993. Final report

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

Eley, C.; Tolen, T.M.; Benya, J.R.

1993-12-31

The 1993 Advanced Lighting Guidelines document consists of twelve guidelines that provide an overview of specific lighting technologies and design application techniques utilizing energy-efficient lighting practice. Lighting Design Practice assesses energy-efficient lighting strategies, discusses lighting issues, and explains how to obtain quality lighting design and consulting services. Luminaires and Lighting Systems surveys luminaire equipment designed to take advantage of advanced technology lamp products and includes performance tables that allow for accurate estimation of luminaire light output and power input. The additional ten guidelines -- Computer-Aided Lighting Design, Energy-Efficient Fluorescent Ballasts, Full-Size Fluorescent Lamps, Compact Fluorescent Lamps, Tungsten-Halogen Lamps, Metal Halidemore » and HPS Lamps, Daylighting and Lumen Maintenance, Occupant Sensors, Time Scheduling Systems, and Retrofit Control Technologies -- each provide a product technology overview, discuss current products on the lighting equipment market, and provide application techniques. This document is intended for use by electric utility personnel involved in lighting programs, lighting designers, electrical engineers, architects, lighting manufacturers` representatives, and other lighting professionals.« less

Light-attenuating effect of dentin on the polymerization of light-activated restorative resins.

PubMed

Arikawa, Hiroyuki; Kanie, Takahito; Fujii, Koichi; Ban, Seiji; Takahashi, Hideo

2004-12-01

The light-attenuating effect of dentin on the mechanical properties of light-activated composite resins was evaluated using a simple experimental filter. The filter was designed to simulate the light transmittance and light diffusion characteristics of 1.0-mm thick dentin. The depth of cure, surface hardness, and flexural strength for 13 shades of three light-activated restorative resins were examined. These resins were cured either using direct irradiation with a light source, or indirect irradiation through the filter. The attenuation of light intensity by 1.0-mm thick dentin reached 85-90% in the 400-550 nm wavelength region. For all materials, the values of depth of cure, surface hardness on the top and bottom surfaces, and flexural strength of specimens irradiated indirectly through the simulated 1.0-mm thick dentin filter decreased by 37-60%, 16-55%, 50-83%, and 44-82% in comparison with those by direct irradiation, respectively. Recovery from mechanical properties' reduction was achieved when materials were irradiated 1.5-4 times longer than the standard irradiation time.

HORIZONTAL HYBRID SOLAR LIGHT PIPE: AN INTEGRATED SYSTEM OF DAYLIGHT AND ELECTRIC LIGHT

EPA Science Inventory

This project will test the feasibility of an advanced energy efficient perimeter lighting system that integrates daylighting, electric lighting, and lighting controls to reduce electricity consumption. The system is designed to provide adequate illuminance levels in deep-floor...

GATEWAY Demonstrations: OLED Lighting in the Offices of Aurora Lighting Design, Inc.

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

Miller, Naomi J.

At the offices of Aurora Lighting Design, Inc., in Grayslake, IL, the GATEWAY program conducted its first investigation involving OLED lighting. The project experienced several challenges, but also highlighted a number of promising attributes – which indicate that with continued improvements in efficacy, longevity, size, and flexibility, OLEDs could provide a new tool for creative and effective lighting.

Launching Light: Beyond the Bulb for the United Nations' International Year of Light 2015

NASA Astrophysics Data System (ADS)

Arcand, K. K.; Watzke, M.

2015-09-01

In astronomy, light is the language used to understand the Universe. From radio waves to gamma rays, light in all its forms delivers information that helps astronomers learn about the Universe. When the United Nations declared 2015 to be the International Year of Light and Light-based Technologies (IYL2015), it presented an opportunity to share the role that light plays in astronomy and beyond. The IYL2015 also offered a chance to build on experiences and sustain networks from the International Year of Astronomy in 2009. Light: Beyond the Bulb is an IYL2015 project that melds both of these goals. The project takes the form of an exhibit that showcases what light can do, from here on Earth and across the vastness of space, hosted by volunteer networks in public spaces for informal science learning.

Plant Light Measurement & Calculations.

ERIC Educational Resources Information Center

Hershey, David R.

1991-01-01

The differences between measuring light intensity for the human eye and for plant photosynthesis are discussed. Conversion factors needed to convert various units of light are provided. Photosynthetic efficiency and the electricity costs for plants to undergo photosynthesis using interior lighting are described. (KR)

Roadway lighting and driver safety

DOT National Transportation Integrated Search

2003-05-01

The objectives of this project were to: a)analyze the safety benefits associated with roadway lighting; b)determine the design of the lighting installation necessary to provide an adequate level of lighting; c)investigate how lighting affects the dri...

Plants Actively Avoid State Transitions upon Changes in Light Intensity: Role of Light-Harvesting Complex II Protein Dephosphorylation in High Light1[OPEN

PubMed Central

Suorsa, Marjaana; Rantala, Marjaana; Aro, Eva-Mari

2015-01-01

Photosystem II (PSII) core and light-harvesting complex II (LHCII) proteins in plant chloroplasts undergo reversible phosphorylation upon changes in light intensity (being under control of redox-regulated STN7 and STN8 kinases and TAP38/PPH1 and PSII core phosphatases). Shift of plants from growth light to high light results in an increase of PSII core phosphorylation, whereas LHCII phosphorylation concomitantly decreases. Exactly the opposite takes place when plants are shifted to lower light intensity. Despite distinct changes occurring in thylakoid protein phosphorylation upon light intensity changes, the excitation balance between PSII and photosystem I remains unchanged. This differs drastically from the canonical-state transition model induced by artificial states 1 and 2 lights that concomitantly either dephosphorylate or phosphorylate, respectively, both the PSII core and LHCII phosphoproteins. Analysis of the kinase and phosphatase mutants revealed that TAP38/PPH1 phosphatase is crucial in preventing state transition upon increase in light intensity. Indeed, tap38/pph1 mutant revealed strong concomitant phosphorylation of both the PSII core and LHCII proteins upon transfer to high light, thus resembling the wild type under state 2 light. Coordinated function of thylakoid protein kinases and phosphatases is shown to secure balanced excitation energy for both photosystems by preventing state transitions upon changes in light intensity. Moreover, PROTON GRADIENT REGULATION5 (PGR5) is required for proper regulation of thylakoid protein kinases and phosphatases, and the pgr5 mutant mimics phenotypes of tap38/pph1. This shows that there is a close cooperation between the redox- and proton gradient-dependent regulatory mechanisms for proper function of the photosynthetic machinery. PMID:25902812

Low Illumination Light (LIL) Solar Cells: Indoor and Monochromatic Light Harvesting

DTIC Science & Technology

2015-11-01

photovoltaic ( PV ) solar cells under low intensity and narrow light spectrum conditions has not been clearly examined. PV operating values under 1 sun...3. PV Fundamental Losses under Low-Light Conditions 5 4. Experiment Setup 9 4.1 Materials 9 4.1.1 Light Sources and Spectra 9 4.1.2 PV Solar ...http://www.mjinc.com/newsArticle2012_Mar15.html ..........................4 Fig. 4 Three energy and power densities ranges for PV solar cells

Light Pollution: Outdoor lighting is a growing threat to astronomy.

PubMed

Riegel, K W

1973-03-30

There have been major qualitative and quantitative changes in outdoor lighting technology in the last decade. The level of skylight caused by outdoor lighting systems is growing at a very high rate, about 20 percent per year nationwide. In addition, the spectral distribution of man-made light pollution may change in the next decade from one containing a few mercury lines to one containing dozens of lines and a significantly increased continuum level. Light pollution is presently damaging to some astronomical programs, and it is likely to become a major factor limiting progress in the next decade. Suitable sites in the United States for new dark sky observing facilities are very difficult to find. Some of the increase in outdoor illumination is due to the character of national growth and development. Some is due to promotional campaigns, in which questionable arguments involving public safety are presented. There are protective measures which might be adopted by the government; these would significantly aid observational astronomy, without compromising the legitimate outdoor lighting needs of society. Observatories should establish programs to routinely monitor sky brightness as a function of position, wavelength, and time. The astronomical community should establish a mechanism by which such programs can be supported and coordinated.

Light extraction block with curved surface

DOEpatents

Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.

2016-03-22

Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.

Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena

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

Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.

2012-02-16

Light-Front Holography is one of the most remarkable features of the AdS/CFT correspondence. In spite of its present limitations it provides important physical insights into the nonperturbative regime of QCD and its transition to the perturbative domain. This novel framework allows hadronic amplitudes in a higher dimensional anti-de Sitter (AdS) space to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The model leads to an effective confining light-front QCD Hamiltonian and a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z inmore » AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time and determines the off-shell dynamics of the bound-state wavefunctions, and thus the fall-off as a function of the invariant mass of the constituents. The soft-wall holographic model modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics - a semi-classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryons. The model predicts a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number n. The hadron eigensolutions projected on the free Fock basis provides the complete set of valence and non-valence light-front Fock state wavefunctions {Psi}{sub n/H} (x{sub i}, k{sub {perpendicular}i}, {lambda}{sub i}) which describe the hadron's momentum and spin distributions needed to compute the direct measures of hadron structure at the quark and gluon level, such as elastic and transition form factors, distribution amplitudes, structure functions, generalized parton distributions and

Effects of laryngoscope handle light source on the light intensity from disposable laryngoscope blades.

PubMed

Milne, A D; Brousseau, P A; Brousseau, C A

2014-12-01

A bench-top study was performed to assess the effects of different laryngoscope handles on the light intensity delivered from disposable metal or plastic laryngoscope blades. The light intensity from both the handle light sources themselves and the combined handle and laryngoscope blade sets was measured using a custom-designed testing system and light meter. Five samples of each disposable blade type were tested and compared with a standard re-usable stainless steel blade using three different handle/light sources (Vital Signs LED, Heine 2.5 V Xenon and 3.5 V Xenon). The light intensity delivered by the disposable blades ranged from 790 to 3846 lux for the different handle types. Overall, the 3.5 V Heine handle delivered the highest light output (p < 0.007) in comparison with the other handles. For the disposable blades, the overall light output was significantly higher from the plastic than the metal blades (p < 0.001). © 2014 The Association of Anaesthetists of Great Britain and Ireland.

Light Pipe Energy Savings Calculator

NASA Astrophysics Data System (ADS)

Owens, Erin; Behringer, Ernest R.

2009-04-01

Dependence on fossil fuels is unsustainable and therefore a shift to renewable energy sources such as sunlight is required. Light pipes provide a way to utilize sunlight for interior lighting, and can reduce the need for fossil fuel-generated electrical energy. Because consumers considering light pipe installation may be more strongly motivated by cost considerations than by sustainability arguments, an easy means to examine the corresponding costs and benefits is needed to facilitate informed decision-making. The purpose of this American Physical Society Physics and Society Fellowship project is to create a Web-based calculator to allow users to quantify the possible cost savings for their specific light pipe application. Initial calculations show that the illumination provided by light pipes can replace electric light use during the day, and in many cases can supply greater illumination levels than those typically given by electric lighting. While the installation cost of a light pipe is significantly greater than the avoided cost of electricity over the lifetime of the light pipe at current prices, savings may be realized if electricity prices increase.

Is part-night lighting an effective measure to limit the impacts of artificial lighting on bats?

PubMed

Azam, Clémentine; Kerbiriou, Christian; Vernet, Arthur; Julien, Jean-François; Bas, Yves; Plichard, Laura; Maratrat, Julie; Le Viol, Isabelle

2015-12-01

As light pollution is currently considered to be a major threat to biodiversity, different lighting management options are being explored to mitigate the impact of artificial lighting on wildlife. Although part-night lighting schemes have been adopted by many local authorities across Europe to reduce the carbon footprint and save energy, their effects on biodiversity are unknown. Through a paired, in situ experiment, we compared the activity levels of 8 bat species under unlit, part-night, and full-night lighting treatments in a rural area located 60 km south of Paris, France. We selected 36 study locations composed of 1 lit site and a paired unlit control site; 24 of these sites were located in areas subject to part-night lighting schemes, and 12 sites were in areas under standard, full-night lighting. There was significantly more activity on part-night lighting sites compared to full-night lighting sites for the late-emerging, light-sensitive Plecotus spp., and a similar pattern was observable for Myotis spp., although not significant. In contrast, part-night lighting did not influence the activity of early emerging bat species around streetlights, except for Pipistrellus pipistrellus for which there was significantly less activity on part-night lighting sites than on full-night lighting sites. Overall, no significant difference in activity between part- and full-night lighting sites were observed in 5 of the 8 species studied, suggesting that current part-night lighting schemes fail to encompass the range of activity of most bat species. We recommend that such schemes start earlier at night to effectively mitigate the adverse effects of artificial lighting on light-sensitive species, particularly along ecological corridors that are especially important to the persistence of biodiversity in urban landscapes. © 2015 John Wiley & Sons Ltd.

Assessment of the performance of light-emitting diode roadway lighting technology.

DOT National Transportation Integrated Search

2015-10-01

This study, championed by the Virginia Department of Transportation (VDOT) Traffic Engineering : Division, involved a thorough investigation of light-emitting diode (LED) roadway lighting technology by : testing six types of roadway luminaires (inclu...

Getting Pool Light Right.

ERIC Educational Resources Information Center

Hunsaker, Scot

1998-01-01

Examines the use of lighting, both artificial and natural, that can enhance the aesthetic quality and functionality of areas with indoor swimming pools. Discusses glare and shadow-reduction measures that aid competitive events, including lighting above and below water levels, and highlights lighting issues during televised events. Descriptions of…

Macular degeneration - age-related

MedlinePlus

... lining of the eye (fundus photography) Using light waves to view the retina (optical coherence tomography) A ... JA, Vander JF, eds. Ophthalmology Secrets in Color . 4th ed. Philadelphia, PA: Elsevier; 2015:chap 43. Wenick ...

Solid state lighting component

DOEpatents

Yuan, Thomas; Keller, Bernd; Tarsa, Eric; Ibbetson, James; Morgan, Frederick; Dowling, Kevin; Lys, Ihor

2017-10-17

An LED component according to the present invention comprising an array of LED chips mounted on a submount with the LED chips capable of emitting light in response to an electrical signal. The array can comprise LED chips emitting at two colors of light wherein the LED component emits light comprising the combination of the two colors of light. A single lens is included over the array of LED chips. The LED chip array can emit light of greater than 800 lumens with a drive current of less than 150 milli-Amps. The LED chip component can also operate at temperatures less than 3000 degrees K. In one embodiment, the LED array is in a substantially circular pattern on the submount.

Light Source Matters--Students' Explanations about the Behavior of Light When Different Light Sources Are Used in Task Assignments of Optics

ERIC Educational Resources Information Center

Kesonen, Mikko Henri Petteri; Asikainen, Mervi Anita; Hirvonen, Pekka Emil

2017-01-01

In the present article, the context-dependency of student reasoning is studied in a context of optics. We investigated introductory students' explanations about the behavior of light when different light sources, namely a small light bulb and a laser, were used in otherwise identical task assignments. The data was gathered with the aid of pretest…

The effects of prior light history on the suppression of melatonin by light in humans

PubMed Central

Hébert, Marc; Martin, Stacia K.; Lee, Clara; Eastman, Charmane I.

2014-01-01

We investigated the impact of light exposure history on light sensitivity in humans, as assessed by the magnitude of the suppression of melatonin secretion by nocturnal light. The hypothesis was that following a week of increased daytime bright-light exposure, subjects would become less sensitive to light, and that after a week of restriction to dimmer light they would become more sensitive. During the bright week, subjects (n = 12) obtained 4.3 ± 0.4 hr of bright light per day (by going outside and using light boxes indoors). During the dim week, they wore dark goggles (about 2% light transmission) when outside during daylight and spent 1.4 ± 0.9 hr per day outside. Saliva samples were obtained every 30 min for 7 hr in dim light (<15 lux) on two consecutive nights (baseline and test night) at the end of each week. On the test night, 500 lux was presented for 3 hr in the middle of the collection period to suppress melatonin. There was significantly more suppression after the dim week compared with after the bright week (to 53 versus 41% of the baseline night values, P < 0.05). However, there were large individual differences, and the difference between the bright and dim weeks was most pronounced in seven of the 12 subjects. Possible reasons for these individual differences are discussed, including the possibility that 1 wk was not long enough to change light sensitivity in some subjects. In conclusion, this study suggests that the circadian system’s sensitivity to light can be affected by a recent change in light history. PMID:12390501

Entanglement of light-shift compensated atomic spin waves with telecom light.

PubMed

Dudin, Y O; Radnaev, A G; Zhao, R; Blumoff, J Z; Kennedy, T A B; Kuzmich, A

2010-12-31

Entanglement of a 795 nm light polarization qubit and an atomic Rb spin-wave qubit for a storage time of 0.1 s is observed by measuring the violation of Bell's inequality (S=2.65±0.12). Long qubit storage times are achieved by pinning the spin wave in a 1064 nm wavelength optical lattice, with a magic-valued magnetic field superposed to eliminate lattice-induced dephasing. Four-wave mixing in a cold Rb gas is employed to perform light qubit conversion between near infrared (795 nm) and telecom (1367 nm) wavelengths, and after propagation in a telecom fiber, to invert the conversion process. Observed Bell inequality violation (S=2.66±0.09), at 10 ms storage, confirms preservation of memory-light entanglement through the two stages of light qubit frequency conversion.

Short Course in Highway Lighting.

ERIC Educational Resources Information Center

Federal Highway Administration (DOT), Washington, DC.

This course guide in highway lighting includes an overview of trends in highway lighting, illustrated information on three light sources for today's luminaires, a reference guide to lamp classification, specifications for highway lighting equipment, and instructions for calculating appropriate use. Maintenance notes on highway illumination and…

Ocular hazards of light

NASA Technical Reports Server (NTRS)

Sliney, David H.

1994-01-01

The eye is protected against bright light by the natural aversion response to viewing bright light sources. The aversion response normally protects the eye against injury from viewing bright light sources such as the sun, arc lamps and welding arcs, since this aversion limits the duration of exposure to a fraction of a second (about 0.25 s). The principal retinal hazard resulting from viewing bright light sources is photoretinitis, e.g., solar retinitis with an accompanying scotoma which results from staring at the sun. Solar retinitis was once referred to as 'eclipse blindness' and associated 'retinal burn'. Only in recent years has it become clear that photoretinitis results from a photochemical injury mechanism following exposure of the retina to shorter wavelengths in the visible spectrum, i.e., violet and blue light. Prior to conclusive animal experiments at that time, it was thought to be a thermal injury mechanism. However, it has been shown conclusively that an intense exposure to short-wavelength light (hereafter referred to as 'blue light') can cause retinal injury. The product of the dose-rate and the exposure duration always must result in the same exposure dose (in joules-per-square centimeter at the retina) to produce a threshold injury. Blue-light retinal injury (photoretinitis) can result from viewing either an extremely bright light for a short time, or a less bright light for longer exposure periods. This characteristic of photochemical injury mechanisms is termed reciprocity and helps to distinguish these effects from thermal burns, where heat conduction requires a very intense exposure within seconds to cause a retinal coagulation otherwise, surrounding tissue conducts the heat away from the retinal image. Injury thresholds for acute injury in experimental animals for both corneal and retinal effects have been corroborated for the human eye from accident data. Occupational safety limits for exposure to UVR and bright light are based upon this

The need for lighting education

NASA Astrophysics Data System (ADS)

Julian, Warren G.

2002-05-01

It is amazing that in a world now dominated by light - a world that is absolutely dependent upon light - that there is almost no lighting education. In a few countries of the world there exist tertiary level lighting programs but these can be counted on the fingers of two hands. Developments in lighting technology have produced a range of design tools that can lead to improved and energy-efficient lighting. However, most of this technology is 'harder' to use than traditional technology, emphasizing the need for not only improved lighting education but for its initiation. This paper discusses the need for education and uses the example of the University of Sydney program as a possible basis for others to use. It also examines how it is being delivered in Singapore.

Ultrafast Graphene Light Emitters.

PubMed

Kim, Young Duck; Gao, Yuanda; Shiue, Ren-Jye; Wang, Lei; Aslan, Ozgur Burak; Bae, Myung-Ho; Kim, Hyungsik; Seo, Dongjea; Choi, Heon-Jin; Kim, Suk Hyun; Nemilentsau, Andrei; Low, Tony; Tan, Cheng; Efetov, Dmitri K; Taniguchi, Takashi; Watanabe, Kenji; Shepard, Kenneth L; Heinz, Tony F; Englund, Dirk; Hone, James

2018-02-14

Ultrafast electrically driven nanoscale light sources are critical components in nanophotonics. Compound semiconductor-based light sources for the nanophotonic platforms have been extensively investigated over the past decades. However, monolithic ultrafast light sources with a small footprint remain a challenge. Here, we demonstrate electrically driven ultrafast graphene light emitters that achieve light pulse generation with up to 10 GHz bandwidth across a broad spectral range from the visible to the near-infrared. The fast response results from ultrafast charge-carrier dynamics in graphene and weak electron-acoustic phonon-mediated coupling between the electronic and lattice degrees of freedom. We also find that encapsulating graphene with hexagonal boron nitride (hBN) layers strongly modifies the emission spectrum by changing the local optical density of states, thus providing up to 460% enhancement compared to the gray-body thermal radiation for a broad peak centered at 720 nm. Furthermore, the hBN encapsulation layers permit stable and bright visible thermal radiation with electronic temperatures up to 2000 K under ambient conditions as well as efficient ultrafast electronic cooling via near-field coupling to hybrid polaritonic modes under electrical excitation. These high-speed graphene light emitters provide a promising path for on-chip light sources for optical communications and other optoelectronic applications.

Effect of health messages about "Light" and "Ultra Light" cigarettes on beliefs and quitting intent.

PubMed

Shiffman, S; Pillitteri, J L; Burton, S L; Rohay, J M; Gitchell, J G

2001-01-01

To test the impact of three health messages focusing on vent holes, sensory effects of Light and Ultra Light cigarettes, or health consequences of smoking, respectively, on beliefs and quitting intentions. In the course of a random digit dialed telephone survey, subjects were randomised to hear one of three messages. To test the effects of the messages, beliefs and quitting intentions were assessed both pre- and post-message. Daily smokers (n = 2120) of Regular (46%), Light (39%), and Ultra Light (15%) cigarettes in the USA. The sample was weighted to match the US smoker population on age, sex, and ethnicity. Beliefs were summarised on three dimensions: Safety (reduced health risk), Delivery (lower tar and nicotine delivery), and Sensation (less harsh). Quitting interest was captured by the "quit index", an aggregate measure of quitting interest and intent. The message focusing on smokers' sensory perceptions of Light and Ultra Light cigarettes resulted in the most positive change in beliefs about safety, delivery, and intent to quit, and was particularly effective among those who believed that these cigarettes were less harsh. The effect was most pronounced among young adults, and among smokers of Light and Ultra Light brands who most endorsed their sensory benefits. Addressing smokers' sensory experience that Light and Ultra Light cigarettes feel less harsh may be a promising strategy for changing their misconceptions about these cigarettes and enhancing their interest in quitting. Media counter-advertising on Lights and Ultra Lights, focusing on sensory aspects of these cigarettes, may be an important part of tobacco control efforts.

Effects of light-emitting diode light v. fluorescent light on growing performance, activity levels and well-being of non-beak-trimmed W-36 pullets.

PubMed

Liu, K; Xin, H; Settar, P

2018-01-01

More energy-efficient, readily dimmable, long-lasting and more affordable light-emitting diode (LED) lights are increasingly finding applications in poultry production facilities. Despite anecdotal evidence about the benefits of such lighting on bird performance and behavior, concrete research data were lacking. In this study, a commercial poultry-specific LED light (dim-to-blue, controllable correlated color temperature (CCT) from 4500 to 5300 K) and a typical compact fluorescent light (CFL) (soft white, CCT=2700 K) were compared with regards to their effects on growing performance, activity levels, and feather and comb conditions of non-beak-trimmed W-36 pullets during a 14-week rearing period. A total of 1280-day-old pullets in two successive batches, 640 birds each, were used in the study. For each batch, pullets were randomly assigned to four identical litter-floor rooms equipped with perches, two rooms per light regimen, 160 birds per room. Body weight, BW uniformity (BWU), BW gain (BWG) and cumulative mortality rate (CMR) of the pullets were determined every 2 weeks from day-old to 14 weeks of age (WOA). Activity levels of the pullets at 5 to 14 WOA were delineated by movement index. Results revealed that pullets under the LED and CFL lights had comparable BW (1140±5 g v. 1135±5 g, P=0.41), BWU (90.8±1.0% v. 91.9±1.0%, P=0.48) and CMR (1.3±0.6% v. 2.7±0.6%, P=0.18) at 14 WOA despite some varying BWG during the rearing. Circadian activity levels of the pullets were higher under the LED light than under the CFL light, possibly resulting from differences in spectrum and/or perceived light intensity between the two lights. No feather damage or comb wound was apparent in either light regimen at the end of the rearing period. The results contribute to understanding the impact of emerging LED lights on pullets rearing which is a critical component of egg production.

Quantifying and Reducing Light Pollution

NASA Astrophysics Data System (ADS)

Gokhale, Vayujeet; Caples, David; Goins, Jordan; Herdman, Ashley; Pankey, Steven; Wren, Emily

2018-06-01

We describe the current level of light pollution in and around Kirksville, Missouri and around Anderson Mesa near Flagstaff, Arizona. We quantify the amount of light that is projected up towards the sky, instead of the ground, using Unihedron sky quality meters installed at various locations. We also present results from DSLR photometry of several standard stars, and compare the photometric quality of the data collected at locations with varying levels of light pollution. Presently, light fixture shields and ‘warm-colored’ lights are being installed on Truman State University’s campus in order to reduce light pollution. We discuss the experimental procedure we use to test the effectiveness of the different light fixtures shields in a controlled setting inside the Del and Norma Robison Planetarium.Apart from negatively affecting the quality of the night sky for astronomers, light pollution adversely affects migratory patterns of some animals and sleep-patterns in humans, increases our carbon footprint, and wastes resources and money. This problem threatens to get particularly acute with the increasing use of outdoor LED lamps. We conclude with a call to action to all professional and amateur astronomers to act against the growing nuisance of light pollution.

Intimate Coupling of Photocatalysis and Biodegradation for Degrading Phenol Using Different Light Types: Visible Light vs UV Light.

PubMed

Zhou, Dandan; Xu, Zhengxue; Dong, Shanshan; Huo, Mingxin; Dong, Shuangshi; Tian, Xiadi; Cui, Bin; Xiong, Houfeng; Li, Tingting; Ma, Dongmei

2015-07-07

Intimate coupling of photocatalysis and biodegradation (ICPB) technology is attractive for phenolic wastewater treatment, but has only been investigated using UV light (called UPCB). We examined the intimate coupling of visible-light-induced photocatalysis and biodegradation (VPCB) for the first time. Our catalyst was prepared doping both of Er(3+) and YAlO3 into TiO2 which were supported on macroporous carriers. The macroporous carriers was used to support for the biofilms as well. 99.8% removal efficiency of phenol was achieved in the VPCB, and this was 32.6% higher than that in the UPCB. Mineralization capability of UPCB was even worse, due to less adsorbable intermediates and cell lysis induced soluble microbial products release. The lower phenol degradation in the UPCB was due to the serious detachment of the biofilms, and then the microbes responsible for phenol degradation were insufficient due to disinfection by UV irradiation. In contrast, microbial communities in the carriers were well protected under visible light irradiation and extracellular polymeric substances secretion was enhanced. Thus, we found that the photocatalytic reaction and biodegradation were intimately coupled in the VPCB, resulting in 64.0% removal of dissolved organic carbon. Therefore, we found visible light has some advantages over UV light in the ICPB technology.

Light pollution and solid-state lighting: reducing the carbon dioxide footprint is not enough

NASA Astrophysics Data System (ADS)

Bará, Salvador

2013-11-01

Public and private lighting account for a relevant share of the overall electric power consumption worldwide. The pressing need of reducing the carbon dioxide emissions as well as of lowering the lumen•hour price tag has fostered the search for alternative lighting technologies to substitute for the incandescent and gas-discharge based lamps. The most successful approach to date, solid-state lighting, is already finding its way into the public lighting market, very often helped by substantial public investments and support. LED-based sources have distinct advantages: under controlled coditions their efficacy equals or surpasses that of conventional solutions, their small source size allows for an efficient collimation of the lightbeam (delivering the photons where they are actually needed and reducing lightspill on the surrounding areas), and they can be switched and/or dimmed on demand at very high rates, thus allowing for a taylored schedule of lighting. However, energy savings and carbon dioxide reduction are not the only crucial issues faced by present day lighting. A growing body of research has shown the significance of the spectral composition of light when it comes to assess the detrimental effects of artificial light-at-night (ALAN). The potential ALAN blueshift associated to the deployment of LED-based lighting systems has raised sensible concerns about its scientific, cultural, ecological and public health consequences, which can be further amplified if an increased light consumption is produced due to the rebound effect. This contribution addresses some of the challenges that these issues pose to the Optics and Photonics community.

Dependency between light intensity and refractive development under light-dark cycles.

PubMed

Cohen, Yuval; Belkin, Michael; Yehezkel, Oren; Solomon, Arieh S; Polat, Uri

2011-01-01

The emmetropization process involves fine-tuning the refractive state by altering the refractive components toward zero refraction. In this study, we provided light-dark cycle conditions at several intensities and examined the effect of light intensity on the progression of chicks' emmetropization. Chicks under high-, medium-, and low-light intensities (10,000, 500, and 50 lux, respectively) were followed for 90 days by retinoscopy, keratometry, as well as ultrasound measurements. Emmetropization was reached from days 30-50 and from days 50-60 for the low- and medium-intensity groups, respectively. On day 90, most chicks in the low-intensity group were myopic, with a mean refraction of -2.41D (95% confidence interval (CI) -2.9 to -1.8D), whereas no chicks in the high-intensity group developed myopia, but they exhibited a stable mean hyperopia of +1.1D. The medium-intensity group had a mean refraction of +0.03D. The low-intensity group had a deeper vitreous chamber depth and a longer axial length compared with the high-intensity group, and shifted refraction to the myopic side. The low-intensity group had a flatter corneal curvature, a deeper anterior chamber, and a thinner lens compared with the high-intensity group, and shifted refraction to the hyperopic side. In all groups the corneal power was correlated with the three examined levels of log light intensity for all examined times (e.g., day 20 r = 0.6 P < 0.0001, day 90 r = 0.56 P < 0.0001). Thus, under light-dark cycles, light intensity is an environmental factor that modulates the process of emmetropization, and the low intensity of ambient light is a risk factor for developing myopia. Copyright © 2010 Elsevier Ltd. All rights reserved.

A light reflecting apparatus including a multi-aberration light reflecting surface

DOEpatents

Sawicki, R.H.; Sweatt, W.

1985-11-21

A light reflecting apparatus including a multi-aberration bendable light reflecting surface is disclosed herein. This apparatus includes a structural assembly comprised of a rectangular plate which is resiliently bendable, to a limited extent, and which has a front side defining the multi-aberration light reflecting surface and an opposite back side, and a plurality of straight leg members rigidly connected with the back side of the plate and extending rearwardly therefrom. The apparatus also includes a number of different adjustment mechanisms, each of which is connected with specific ones of the leg members. These mechanisms are adjustably movable in different ways for applying corresponding forces to the leg members in order to bend the rectangular plate and light reflecting surface into different predetermined curvatures and which specifically include quadratic and cubic curvatures corresponding to different optical aberrations.

Deep sequencing reveals transcriptome re-programming of Taxus × media cells to the elicitation with methyl jasmonate.

PubMed

Sun, Guiling; Yang, Yanfang; Xie, Fuliang; Wen, Jian-Fan; Wu, Jianqiang; Wilson, Iain W; Tang, Qi; Liu, Hongwei; Qiu, Deyou

2013-01-01

Plant cell culture represents an alternative source for producing high-value secondary metabolites including paclitaxel (Taxol®), which is mainly produced in Taxus and has been widely used in cancer chemotherapy. The phytohormone methyl jasmonate (MeJA) can significantly increase the production of paclitaxel, which is induced in plants as a secondary metabolite possibly in defense against herbivores and pathogens. In cell culture, MeJA also elicits the accumulation of paclitaxel; however, the mechanism is still largely unknown. To obtain insight into the global regulation mechanism of MeJA in the steady state of paclitaxel production (7 days after MeJA addition), especially on paclitaxel biosynthesis, we sequenced the transcriptomes of MeJA-treated and untreated Taxus × media cells and obtained ∼ 32.5 M high quality reads, from which 40,348 unique sequences were obtained by de novo assembly. Expression level analysis indicated that a large number of genes were associated with transcriptional regulation, DNA and histone modification, and MeJA signaling network. All the 29 known genes involved in the biosynthesis of terpenoid backbone and paclitaxel were found with 18 genes showing increased transcript abundance following elicitation of MeJA. The significantly up-regulated changes of 9 genes in paclitaxel biosynthesis were validated by qRT-PCR assays. According to the expression changes and the previously proposed enzyme functions, multiple candidates for the unknown steps in paclitaxel biosynthesis were identified. We also found some genes putatively involved in the transport and degradation of paclitaxel. Potential target prediction of miRNAs indicated that miRNAs may play an important role in the gene expression regulation following the elicitation of MeJA. Our results shed new light on the global regulation mechanism by which MeJA regulates the physiology of Taxus cells and is helpful to understand how MeJA elicits other plant species besides Taxus.

Shedding Some Light.

ERIC Educational Resources Information Center

Whitney, Tim

1998-01-01

Discusses the basics of designing natural and artificial light in an indoor athletic facility. Also examines individual lighting requirements of typical rooms such as weight and fitness rooms, aerobics and multipurpose rooms, gymnasiums, field houses, pools, and racquetball and squash courts. (GR)

Provide Natural Light | Efficient Windows Collaborative

Science.gov Websites

illumination when desired. Providing Balanced Lighting A balance of light is important both for visual comfort protected from excessive light levels. The balance of light in a space depends on the overall number and furnishings. An improved balance of light can be created by providing light from at least two directions, such

Light shielding apparatus

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

Miller, Richard Dean; Thom, Robert Anthony

A light shielding apparatus for blocking light from reaching an electronic device, the light shielding apparatus including left and right support assemblies, a cross member, and an opaque shroud. The support assemblies each include primary support structure, a mounting element for removably connecting the apparatus to the electronic device, and a support member depending from the primary support structure for retaining the apparatus in an upright orientation. The cross member couples the left and right support assemblies together and spaces them apart according to the size and shape of the electronic device. The shroud may be removably and adjustably connectablemore » to the left and right support assemblies and configured to take a cylindrical dome shape so as to form a central space covered from above. The opaque shroud prevents light from entering the central space and contacting sensitive elements of the electronic device.« less

Seeing "the Dress" in the Right Light: Perceived Colors and Inferred Light Sources.

PubMed

Chetverikov, Andrey; Ivanchei, Ivan

2016-08-01

In the well-known "dress" photograph, people either see the dress as blue with black stripes or as white with golden stripes. We suggest that the perception of colors is guided by the scene interpretation and the inferred positions of light sources. We tested this hypothesis in two online studies using color matching to estimate the colors observers see, while controlling for individual differences in gray point bias and color discrimination. Study 1 demonstrates that the interpretation of the dress corresponds to differences in perceived colors. Moreover, people who perceive the dress as blue-and-black are two times more likely to consider the light source as frontal, than those who see the white-and-gold dress. The inferred light sources, in turn, depend on the circadian changes in ambient light. The interpretation of the scene background as a wall or a mirror is consistent with the perceived colors as well. Study 2 shows that matching provides reliable results on differing devices and replicates the findings on scene interpretation and light sources. Additionally, we show that participants' environmental lighting conditions are an important cue for perceiving the dress colors. The exact mechanisms of how environmental lighting and circadian changes influence the perceived colors of the dress deserve further investigation.

SCHOOL LIGHTING APPLICATION DATA. EXCERPTS FROM THE IES LIGHTING HANDBOOK, 3RD EDITION.

ERIC Educational Resources Information Center

Illuminating Engineering Society, New York, NY.

THIS PUBLICATION REGARDING SCHOOL LIGHTING WAS PREPARED AS A USEFUL ADDITION TO THE AMERICAN STANDARD GUIDE FOR SCHOOL LIGHTING. THE MATERIAL HAS BEEN EXTRACTED FROM THE IES LIGHTING HANDBOOK TO INCLUDE A MORE DETAILED TREATMENT OF SUBJECTS TO WHICH THE DESIGNER MUST GIVE IMPORTANT CONSIDERATION. THERE IS A MORE EXTENSIVE TREATMENT OF REFLECTED…

Refrigerated display case lighting with LEDs

NASA Astrophysics Data System (ADS)

Raghavan, Ramesh; Narendran, Nadarajah

2002-11-01

The rapid development of high brightness light emitting diodes (LEDs) has triggered many applications, especially in the area of display lighting. This paper focuses on the application of white LEDs in refrigerated display cases. The fluorescent lighting presently used in commercial refrigerators is inefficient in the application and also it provides poor lighting for merchandising. A laboratory human factors experiment was conducted to assess the preference for the different lighting systems, namely, fluorescent and LED. Two refrigerated display cases, one with the traditional fluorescent lighting system and the other with a prototype LED lighting system, were placed side-by-side in a laboratory setting. Illuminance measurements made within the two display cases showed that the lighting was more uniform with the LED system compared to the traditional fluorescent system. Sixteen human subjects participated in this study and rated their preference for the two lighting systems. The results show that human subjects strongly preferred the display case with the LED lighting. The authors of this manuscript believe a field study would be greatly beneficial to further confirm these results and to understand the relationship between preference and sales. Considering the luminous efficacy of white LEDs presently available in the marketplace, it is possible to develop a LED based lighting system for commercial refrigerators that is competitive with fluorescent lighting system in terms of energy use. The LED based lighting would provide better lighting than traditional fluorescent lighting.

[LIGHT POLLUTION AS THE HYGIENIC PROBLEM].

PubMed

Kaptsov, V A; Gerasev, V F; Deynego, V N

2015-01-01

Mass introduction of lighting devices according to the concept of "maximum coverage area" and multistoried buildings of cities gave rise to light pollution, which became a problem for astronomers, ecologists and hygienists. Analysis of modern lighting devices and installations has shown that about 30-45% of the luminous flux becomes the light pollution. Night lighting of cities causes both direct and indirect damage to the environment, leads to unnecessary energy wastes. So in the USA due to excessive light there is wasted about 2 million barrels of oil per day. Light pollution affects the human hormonal system, causing various health disorders, such as insomnia and depression as a consequence. The light pollution through the ganglion cells of the retina affects the synthesis of melatonin by the pineal gland (epiphysis) and contributes to its calcification, which greatly affects the human psyche. At present, many countries have been paying much state attention to this problem via delivery of national documents and change of the concept of the designing of lighting devices and installations. The essence of this concept--to shine with a preset quality of light only in the right place at the specified time interval. This reduces the light pollution, saves energy and increases the environmental safety of lighting. There is presented an example of a technical solution to reduce the light pollution in the application of the light panel in the form of the gradient of the light guide generator project development.

Effect of eccentricity and light level on the timing of light adaptation mechanisms.

PubMed

Barrionuevo, Pablo A; Matesanz, Beatriz M; Gloriani, Alejandro H; Arranz, Isabel; Issolio, Luis; Mar, Santiago; Aparicio, Juan A

2018-04-01

We explored the complexity of the light adaptation process, assessing adaptation recovery (Ar) at different eccentricities and light levels. Luminance thresholds were obtained with transient background fields at mesopic and photopic light levels for temporal retinal eccentricities (0°-15°) with test/background stimulus size of 0.5°/1° using a staircase procedure in a two-channel Maxwellian view optical system. Ar was obtained in comparison with steady data [Vis. Res.125, 12 (2016)VISRAM0042-698910.1016/j.visres.2016.04.008]. Light level proportionally affects Ar only at fovea. Photopic extrafoveal thresholds were one log unit higher for transient conditions. Adaptation was equally fast at low light levels for different retinal locations with variations mainly affected by noise. These results evidence different timing in the mechanisms of adaptation involved.

Biomimetic light-harvesting funnels for re-directioning of diffuse light.

PubMed

Pieper, Alexander; Hohgardt, Manuel; Willich, Maximilian; Gacek, Daniel Alexander; Hafi, Nour; Pfennig, Dominik; Albrecht, Andreas; Walla, Peter Jomo

2018-02-14

Efficient sunlight harvesting and re-directioning onto small areas has great potential for more widespread use of precious high-performance photovoltaics but so far intrinsic solar concentrator loss mechanisms outweighed the benefits. Here we present an antenna concept allowing high light absorption without high reabsorption or escape-cone losses. An excess of randomly oriented pigments collects light from any direction and funnels the energy to individual acceptors all having identical orientations and emitting ~90% of photons into angles suitable for total internal reflection waveguiding to desired energy converters (funneling diffuse-light re-directioning, FunDiLight). This is achieved using distinct molecules that align efficiently within stretched polymers together with others staying randomly orientated. Emission quantum efficiencies can be >80% and single-foil reabsorption <0.5%. Efficient donor-pool energy funneling, dipole re-orientation, and ~1.5-2 nm nearest donor-acceptor transfer occurs within hundreds to ~20 ps. Single-molecule 3D-polarization experiments confirm nearly parallel emitters. Stacked pigment selection may allow coverage of the entire solar spectrum.

Light-Emitting Pickles

ERIC Educational Resources Information Center

Vollmer, M.; Mollmann, K-P.

2015-01-01

We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

Development of a circadian light source

NASA Astrophysics Data System (ADS)

Nicol, David B.; Ferguson, Ian T.

2002-11-01

Solid state lighting presents a new paradigm for lighting - controllability. Certain characteristics of the lighting environment can be manipulated, because of the possibility of using multiple LEDs of different emission wavelengths as the illumination source. This will provide a new, versatile, general illumination source due to the ability to vary the spectral power distribution. New effects beyond the visual may be achieved that are not possible with conventional light sources. Illumination has long been the primary function of lighting but as the lighting industry has matured the psychological aspects of lighting have been considered by designers; for example, choosing a particular lighting distribution or color variation in retail applications. The next step in the evolution of light is to consider the physiological effects of lighting that cause biological changes in a person within the environment. This work presents the development of a source that may have important bearing on this area of lighting. A circadian light source has been developed to provide an illumination source that works by modulating its correlated color temperature to mimic the changes in natural daylight through the day. In addition, this source can cause or control physiological effects for a person illuminated by it. The importance of this is seen in the human circadian rhythm's peak response corresponding to blue light at ~460 nm which corresponds to the primary spectral difference in increasing color temperature. The device works by adding blue light to a broadband source or mixing polychromatic light to mimic the variation of color temperature observed for the Planckian Locus on the CIE diagram. This device can have several applications including: a tool for researchers in this area, a general illumination lighting technology, and a light therapy device.

Joliet Junior College and the 2015 International Year of Light's Cosmic Light Theme

NASA Astrophysics Data System (ADS)

D'Cruz, Noella L.

2015-01-01

We teach "Descriptive Astronomy" and "Life in the Universe" courses for non-science majors at Joliet Junior College, Joliet IL. We also occasionally present planetarium shows at the college's planetarium. In 2015, we plan to highlight the "Cosmic Light" theme of the 2015 International Year of Light through some of our teaching and outreach activities. For several years, together with our students, we have participated in the Globe at Night light pollution program. In 2015, we plan to continue our participation in this program and we will continue to encourage our students to participate on their own from other locations. We will present a live planetarium show on Light Pollution in Spring 2015 as part of the college's Brown Bag Lecture Series. We plan to develop and present one or two live planetarium presentations that focus on studying astronomical objects across the electromagnetic spectrum during 2015. Also in Spring 2015, we plan to include projects that highlight the International Year of Light in our Descriptive Astronomy course offerings. Our poster will provide details of these "Cosmic Light" activities.

Scaling laws for light weight optics, studies of light weight mirrors mounting and dynamic mirror stress, and light weight mirror and mount designs

NASA Technical Reports Server (NTRS)

Vukobratovich, Daniel; Richard, Ralph M.; Valente, Tina M.; Cho, Myung K.

1990-01-01

Scaling laws for light-weight optical systems are examined. A cubic relationship between mirror diameter and weight has been suggested and used by many designers of optical systems as the best description for all light-weight mirrors. A survey of existing light-weight systems in the open literature was made to clarify this issue. Fifty existing optical systems were surveyed with all varieties of light-weight mirrors including glass and beryllium structured mirrors, contoured mirrors, and very thin solid mirrors. These mirrors were then categorized and weight to diameter ratio was plotted to find a best curve for each case. A best fitting curve program tests nineteen different equations and ranks a goodness-to-fit for each of these equations. The resulting relationship found for each light-weight mirror category helps to quantify light-weight optical systems and methods of fabrication and provides comparisons between mirror types.

Indoor Lighting Facilities

NASA Astrophysics Data System (ADS)

Matsushima, Koji; Saito, Yoshinori; Ichikawa, Shigenori; Kawauchi, Takao; Tanaka, Tsuneo; Hirano, Rika; Tazuke, Fuyuki

According to the statistics on building construction floor area from the Ministry of Land, Infrastructure, Transport and Tourism, the total floor area of building construction started in Japan in 2007 was 160,991 thousand square meters, or 14.8% less than the area of the previous year, and the reduction was the first reduction in the past five years. The office markets in Tokyo and Nagoya were active, as represented by the supplies of skyscrapers, and energy saving measures, such as the adoption of high efficiency lighting equipment, the control for initial stage illuminance, daylight harvesting, and the use of occupancy sensors, were well established. In the field of public construction, including museums, multi-purpose halls, and religious buildings, the total area of the new construction was 10.8% less than the total for the previous year, and this reduction was a continuation of an eleven-year trend. In spaces with high ceiling, the innovation for easy replacement of light sources used with reflection mirror systems and optical fibers was noted. Hospitals adapted to the expectation for improved services in their selection of lighting facilities to improve the residential environment for patients while taking into consideration the needs of the aging population, by their use of devices in corridors to help maintain a continuity of light. In libraries, a pendant system was developed to illuminate both ceilings and book shelves. In the field of theaters and halls, the time limit for repairing existing systems had come for the large facilities that were opened during the theater and hall construction boom of the 1960s through 1980s, and around 26 renovations were done. Almost all the renovations were conversions to intelligent dimming systems and lighting control desks. In the field of stores and commercial facilities, the atmosphere and glitter of the selling floor was produced by new light sources, such as ceramic metal halide lamps and LEDs, which have high

Three-peak standard white organic light-emitting devices for solid-state lighting

NASA Astrophysics Data System (ADS)

Guo, Kunping; Wei, Bin

2014-12-01

Standard white organic light-emitting device (OLED) lighting provides a warm and comfortable atmosphere and shows mild effect on melatonin suppression. A high-efficiency red OLED employing phosphorescent dopant has been investigated. The device generates saturated red emission with Commission Internationale de l'Eclairage (CIE) coordinates of (0.66, 0.34), characterized by a low driving voltage of 3.5 V and high external quantum efficiency of 20.1% at 130 cd m-2. In addition, we have demonstrated a two-peak cold white OLED by combining with a pure blue emitter with the electroluminescent emission of 464 nm, 6, 12-bis{[N-(3,4-dimethylpheyl)-N-(2,4,5-trimethylphenyl)]} chrysene (BmPAC). It was found that the man-made lighting device capable of yielding a relatively stable color emission within the luminance range of 1000-5000 cd m-2. And the chromaticity coordinates, varying from (0.25, 0.21) to (0.23, 0.21). Furthermore, an ultrathin layer of green-light-emitting tris (2-phenylpyridinato)iridium(Ⅲ) Ir(ppy)3 in the host material was introduced to the emissive region for compensating light. By appropriately controlling the layer thickness, the white light OLED achieved good performance of 1280 cd m-2 at 5.0 V and 5150 cd m-2 at 7.0 V, respectively. The CIE coordinates of the emitted light are quite stable at current densities from 759 cd m-2 to 5150 cd m-2, ranging from (0.34, 0.37) to (0.33, 0.33).

Simultaneous Observations of p-mode Light Walls and Magnetic Reconnection Ejections above Sunspot Light Bridges

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

Hou, Yijun; Zhang, Jun; Li, Ting

Recent high-resolution observations from the Interface Region Imaging Spectrograph reveal bright wall-shaped structures in active regions (ARs), especially above sunspot light bridges. Their most prominent feature is the bright oscillating front in the 1400/1330 Å channel. These structures are named light walls and are often interpreted to be driven by p-mode waves. Above the light bridge of AR 12222 on 2014 December 06, we observed intermittent ejections superimposed on an oscillating light wall in the 1400 Å passband. At the base location of each ejection, the emission enhancement was detected in the Solar Dynamics Observatory 1600 Å channel. Thus, wemore » suggest that in wall bases (light bridges), in addition to the leaked p-mode waves consistently driving the oscillating light wall, magnetic reconnection could happen intermittently at some locations and eject the heated plasma upward. Similarly, in the second event occurring in AR 12371 on 2015 June 16, a jet was simultaneously detected in addition to the light wall with a wave-shaped bright front above the light bridge. At the footpoint of this jet, lasting brightening was observed, implying magnetic reconnection at the base. We propose that in these events, two mechanisms, p-mode waves and magnetic reconnection, simultaneously play roles in the light bridge, and lead to the distinct kinetic features of the light walls and the ejection-like activities, respectively. To illustrate the two mechanisms and their resulting activities above light bridges, in this study we present a cartoon model.« less

BLAM (Benthic Light Availability Model): A Proposed Model of Hydrogeomorphic Controls on Light in Rivers

NASA Astrophysics Data System (ADS)

Julian, J. P.; Doyle, M. W.; Stanley, E. H.

2006-12-01

Light is vital to the dynamics of aquatic ecosystems. It drives photosynthesis and photochemical reactions, affects thermal structure, and influences behavior of aquatic biota. Despite the fundamental role of light to riverine ecosystems, light studies in rivers have been mostly neglected because i) boundary conditions (e.g., banks, riparian vegetation) make ambient light measurements difficult, and ii) the optical water quality of rivers is highly variable and difficult to characterize. We propose a benthic light availability model (BLAM) that predicts the percent of incoming photosynthetically active radiation (PAR) available at the river bed. BLAM was developed by quantifying light attenuation of the five hydrogeomorphic controls that dictate riverine light availability: topography, riparian vegetation, channel geometry, optical water quality, and water depth. BLAM was calibrated using hydrogeomorphic data and light measurements from two rivers: Deep River - a 5th-order, turbid river in central North Carolina, and Big Spring Creek - a 2nd-order, optically clear stream in central Wisconsin. We used a series of four PAR sensors to measure i) above-canopy PAR, ii) PAR above water surface, iii) PAR below water surface, and iv) PAR on stream bed. These measurements were used to develop empirical light attenuation coefficients, which were then used in combination with optical water quality measurements, shading analyses, channel surveys, and flow records to quantify the spatial and temporal variability in riverine light availability. Finally, we apply BLAM to the Baraboo River - a 6th-order, 120-mile, unimpounded river in central Wisconsin - in order to characterize light availability along the river continuum (from headwaters to mouth).

Carambola optics for recycling of light.

PubMed

Leutz, Ralf; Fu, Ling; Ries, Harald

2006-04-20

Recycling of light allows the luminance (radiance) emitted by a light source to be increased at the cost of reducing the total luminous flux (radiant power). Recycling of light means returning part of the emitted light to the source, where part of it will escape absorption. An optical design that is suitable for multiple and controlled recycling is described. Carambola optics is named for its resemblance to star fruit. Several pairs of mirrors or prisms redirect light repeatedly onto the source, thus achieving multiple transits of the light through the source. This recycled light exits the carambola in the same phase space as light directly emitted and not recycled.

Light Emitting Diode Flashlights as Effective and Inexpensive Light Sources for Fluorescence Microscopy

PubMed Central

Robertson, J. Brian; Zhang, Yunfei; Johnson, Carl Hirschie

2009-01-01

Summary Light-emitting diodes (LEDs) are becoming more commonly used as light sources for fluorescence microscopy. We describe the adaptation of a commercially available LED flashlight for use as a source for fluorescence excitation. This light source is long-lived, inexpensive, and is effective for excitation in the range of 440–600 nm. PMID:19772530

A tunable lighting system integrated by inorganic and transparent organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Zhang, Jing-jing; Zhang, Tao; Jin, Ya-fang; Liu, Shi-shen; Yuan, Shi-dong; Cui, Zhao; Zhang, Li; Wang, Wei-hui

2014-05-01

A tunable surface-emitting integrated lighting system is constructed using a combination of inorganic light-emitting diodes (LEDs) and transparent organic LEDs (OLEDs). An RB two-color LED is used to supply red and blue light emission, and a green organic LED is used to supply green light emission. Currents of the LED and OLED are tuned to produce a white color, showing different Commission Internationale d'Eclairage (CIE) chromaticity coordinates and correlated color temperatures with a wide adjustable range. Such an integration can compensate for the lack of the LED's luminance uniformity and the transparent OLED's luminance intensity.

Fingerprints in the Light

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] Figure 1

This graph, or spectrum, shows the light from a dusty, distant galaxy located 11 billion light-years away. The galaxy is invisible to optical telescopes, but NASA's Spitzer Space Telescope was able to capture the light from it and dozens of other similar galaxies using heat-seeking infrared eyes.

Spectra are created when an instrument called a spectrograph spreads light out into its basic parts, like a prism turning sunlight into a rainbow. They contain the signatures, or 'fingerprints,' of molecules that contribute to an object's light.

In this case, the galaxy's spectrum reveals the fingerprint for silicate dust (large dip at right), a planetary building block like sand, only smaller. This particular fingerprint is important because it helped astronomers determine how far away the galaxy lies, or more specifically, how much the galaxy's light had stretched, or 'redshifted,' during its journey to Spitzer's eyes. Because the universe is expanding, a galaxy's light will shift toward reddish wavelengths as it moves away from us. This galaxy was found to have a redshift of 1.95, which means that its light took about 11 billion years to get here.

The presence of the silicate fingerprint is also significant because it implies that galaxies were ripe for planetary formation 11 billion years ago - back to a time when the universe was 3 billion years old. The universe is currently believed to be 13.5 billion years old. This is the furthest back in time that silicate dust has been detected around a galaxy.

These data were taken by Spitzer's infrared spectrograph in July, 2004.

Citrus leprosis virus C Infection Results in Hypersensitive-Like Response, Suppression of the JA/ET Plant Defense Pathway and Promotion of the Colonization of Its Mite Vector

PubMed Central

Arena, Gabriella D.; Ramos-González, Pedro L.; Nunes, Maria A.; Ribeiro-Alves, Marcelo; Camargo, Luis E. A.; Kitajima, Elliot W.; Machado, Marcos A.; Freitas-Astúa, Juliana

2016-01-01

Leprosis is a serious disease of citrus caused by Citrus leprosis virus C (CiLV-C, genus Cilevirus) whose transmission is mediated by false spider mites of the genus Brevipalpus. CiLV-C infection does not systemically spread in any of its known host plants, thus remaining restricted to local lesions around the feeding sites of viruliferous mites. To get insight into this unusual pathosystem, we evaluated the expression profiles of genes involved in defense mechanisms of Arabidopsis thaliana and Citrus sinensis upon infestation with non-viruliferous and viruliferous mites by using reverse-transcription qPCR. These results were analyzed together with the production of reactive oxygen species (ROS) and the appearance of dead cells as assessed by histochemical assays. After interaction with non-viruliferous mites, plants locally accumulated ROS and triggered the salicylic acid (SA) and jasmonate/ethylene (JA/ET) pathways. ERF branch of the JA/ET pathways was highly activated. In contrast, JA pathway genes were markedly suppressed upon the CiLV-C infection mediated by viruliferous mites. Viral infection also intensified the ROS burst and cell death, and enhanced the expression of genes involved in the RNA silencing mechanism and SA pathway. After 13 days of infestation of two sets of Arabidopsis plants with non-viruliferous and viruliferous mites, the number of mites in the CiLV-C infected Arabidopsis plants was significantly higher than in those infested with the non-viruliferous ones. Oviposition of the viruliferous mites occurred preferentially in the CiLV-C infected leaves. Based on these results, we postulated the first model of plant/Brevipalpus mite/cilevirus interaction in which cells surrounding the feeding sites of viruliferous mites typify the outcome of a hypersensitive-like response, whereas viral infection induces changes in the behavior of its vector. PMID:27933078

49 CFR 176.148 - Artificial lighting.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Artificial lighting. 176.148 Section 176.148... Requirements for Class 1 (Explosive) Materials Precautions During Loading and Unloading § 176.148 Artificial lighting. Electric lights, except arc lights, are the only form of artificial lighting permitted when...

49 CFR 176.148 - Artificial lighting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Artificial lighting. 176.148 Section 176.148... Requirements for Class 1 (Explosive) Materials Precautions During Loading and Unloading § 176.148 Artificial lighting. Electric lights, except arc lights, are the only form of artificial lighting permitted when...

Reduced flight-to-light behaviour of moth populations exposed to long-term urban light pollution

PubMed Central

Ebert, Dieter

2016-01-01

The globally increasing light pollution is a well-recognized threat to ecosystems, with negative effects on human, animal and plant wellbeing. The most well-known and widely documented consequence of light pollution is the generally fatal attraction of nocturnal insects to artificial light sources. However, the evolutionary consequences are unknown. Here we report that moth populations from urban areas with high, globally relevant levels of light pollution over several decades show a significantly reduced flight-to-light behaviour compared with populations of the same species from pristine dark-sky habitats. Using a common garden setting, we reared moths from 10 different populations from early-instar larvae and experimentally compared their flight-to-light behaviour under standardized conditions. Moths from urban populations had a significant reduction in the flight-to-light behaviour compared with pristine populations. The reduced attraction to light sources of ‘city moths' may directly increase these individuals' survival and reproduction. We anticipate that it comes with a reduced mobility, which negatively affects foraging as well as colonization ability. As nocturnal insects are of eminent significance as pollinators and the primary food source of many vertebrates, an evolutionary change of the flight-to-light behaviour thereby potentially cascades across species interaction networks. PMID:27072407

Reduced flight-to-light behaviour of moth populations exposed to long-term urban light pollution.

PubMed

Altermatt, Florian; Ebert, Dieter

2016-04-01

The globally increasing light pollution is a well-recognized threat to ecosystems, with negative effects on human, animal and plant wellbeing. The most well-known and widely documented consequence of light pollution is the generally fatal attraction of nocturnal insects to artificial light sources. However, the evolutionary consequences are unknown. Here we report that moth populations from urban areas with high, globally relevant levels of light pollution over several decades show a significantly reduced flight-to-light behaviour compared with populations of the same species from pristine dark-sky habitats. Using a common garden setting, we reared moths from 10 different populations from early-instar larvae and experimentally compared their flight-to-light behaviour under standardized conditions. Moths from urban populations had a significant reduction in the flight-to-light behaviour compared with pristine populations. The reduced attraction to light sources of 'city moths' may directly increase these individuals' survival and reproduction. We anticipate that it comes with a reduced mobility, which negatively affects foraging as well as colonization ability. As nocturnal insects are of eminent significance as pollinators and the primary food source of many vertebrates, an evolutionary change of the flight-to-light behaviour thereby potentially cascades across species interaction networks. © 2016 The Author(s).

The light ion trough.

NASA Technical Reports Server (NTRS)

Taylor, H. A., Jr.

1972-01-01

A distinct feature of the ion composition results from the OGO-2, 4 and 6 satellites is the light ion trough, wherein the mid-latitude concentrations of H+ and He+ decrease sharply with latitude. In contrast to the 'main trough' in electron density observed primarily as a nightside phenomenon, the light ion trough persists during both day and night. For daytime winter hemisphere conditions and for all seasons during night, the mid-latitude light ion concentration decrease is a pronounced feature. In the dayside summer and equinox hemispheres, the rate of light ion decrease with latitude is comparatively gradual, and the trough boundary is less well defined, particularly for quiet magnetic conditions. In response to magnetic storms, the light ion trough minimum moves equatorward, and deepens, consistent with earlier evidence of the contraction of the plasmasphere in response to storm time enhancements in magnetospheric plasma convection.

Contrasting trends in light pollution across Europe based on satellite observed night time lights.

PubMed

Bennie, Jonathan; Davies, Thomas W; Duffy, James P; Inger, Richard; Gaston, Kevin J

2014-01-21

Since the 1970s nighttime satellite images of the Earth from space have provided a striking illustration of the extent of artificial light. Meanwhile, growing awareness of adverse impacts of artificial light at night on scientific astronomy, human health, ecological processes and aesthetic enjoyment of the night sky has led to recognition of light pollution as a significant global environmental issue. Links between economic activity, population growth and artificial light are well documented in rapidly developing regions. Applying a novel method to analysis of satellite images of European nighttime lights over 15 years, we show that while the continental trend is towards increasing brightness, some economically developed regions show more complex patterns with large areas decreasing in observed brightness over this period. This highlights that opportunities exist to constrain and even reduce the environmental impact of artificial light pollution while delivering cost and energy-saving benefits.

Light based anti-infectives: ultraviolet C irradiation, photodynamic therapy, blue light, and beyond

PubMed Central

Yin, Rui; Dai, Tianhong; Avci, Pinar; Jorge, Ana Elisa Serafim; de Melo, Wanessa CMA; Vecchio, Daniela; Huang, Ying-Ying; Gupta, Asheesh; Hamblin, Michael R

2013-01-01

Owing to the worldwide increase in antibiotic resistance, researchers are investigating alternative anti-infective strategies to which it is supposed microorganisms will be unable to develop resistance. Prominent among these strategies, is a group of approaches which rely on light to deliver the killing blow. As is well known, ultraviolet light, particularly UVC (200–280nm), is germicidal, but it has not been much developed as an anti-infective approach until recently, when it was realized that the possible adverse effects to host tissue were relatively minor compared to its high activity in killing pathogens. Photodynamic therapy is the combination of non-toxic photosensitizing dyes with harmless visible light that together produce abundant destructive reactive oxygen species (ROS). Certain cationic dyes or photosensitizers have good specificity for binding to microbial cells while sparing host mammalian cells and can be used for treating many localized infections, both superficial and even deep-seated by using fiber optic delivered light. Many microbial cells are highly sensitive to killing by blue light (400–470 nm) due to accumulation of naturally occurring photosensitizers such as porphyrins and flavins. Near infrared light has also been shown to have antimicrobial effects against certain species. Clinical applications of these technologies include skin, dental, wound, stomach, nasal, toenail and other infections which are amenable to effective light delivery. PMID:24060701

Lighting for Schools.

ERIC Educational Resources Information Center

Benya, James R.

This publication highlights some of the benefits of proper daylighting design in educational facilities, discusses energy efficient electric lighting choices schools can make that are long lasting and require little maintenance, and offers six steps for designing lighting systems that use half the energy of earlier conventional designs. Several…

The relevance of light diffusion profiles for interstitial PDT using light-diffusing optical fibers

NASA Astrophysics Data System (ADS)

Stringasci, Mirian D.; Fortunato, Thereza C.; Moriyama, Lilian T.; Vollet Filho, José Dirceu; Bagnato, Vanderlei S.; Kurachi, Cristina

2017-02-01

Photodynamic therapy (PDT) is a technique used for several tumor types treatment. Light penetration on biological tissue is one limiting factor for PDT applied to large tumors. An alternative is using interstitial PDT, in which optical fibers are inserted into tumors. Cylindrical diffusers have been used in interstitial PDT. Light emission of different diffusers depends on the manufacturing process, size and optical properties of fibers, which make difficult to establish an adequate light dosimetry, since usually light profile is not designed for direct tissue-fiber contact. This study discusses the relevance of light distribution by a cylindrical diffuser into a turbid lipid emulsion solution, and how parts of a single diffuser contribute to illumination. A 2 cm-long cylindrical diffuser optical fiber was connected to a diode laser (630 nm), and the light spatial distribution was measured by scanning the solution with a collection probe. From the light field profile generated by a 1 mm-long intermediary element of a 20 mm-long cylindrical diffuser, recovery of light distribution for the entire diffuser was obtained. PDT was performed in rat healthy liver for a real treatment outcome analysis. By using computational tools, a typical necrosis profile generated by the irradiation with such a diffuser fiber was reconstructed. The results showed that it was possible predicting theoretically the shape of a necrosis profile in a healthy, homogeneous tissue with reasonable accuracy. The ability to predict the necrosis profile obtained from an interstitial illumination by optical diffusers has the potential improve light dosimetry for interstitial PDT.

49 CFR 229.127 - Cab lights.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Cab lights. 229.127 Section 229.127 Transportation... lights. (a) Each locomotive shall have cab lights which will provide sufficient illumination for the... normal positions in the cab. These lights shall be located, constructed, and maintained so that light...

49 CFR 229.127 - Cab lights.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Cab lights. 229.127 Section 229.127 Transportation... lights. (a) Each locomotive shall have cab lights which will provide sufficient illumination for the... normal positions in the cab. These lights shall be located, constructed, and maintained so that light...

49 CFR 229.127 - Cab lights.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Cab lights. 229.127 Section 229.127 Transportation... lights. (a) Each locomotive shall have cab lights which will provide sufficient illumination for the... normal positions in the cab. These lights shall be located, constructed, and maintained so that light...

49 CFR 229.127 - Cab lights.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Cab lights. 229.127 Section 229.127 Transportation... lights. (a) Each locomotive shall have cab lights which will provide sufficient illumination for the... normal positions in the cab. These lights shall be located, constructed, and maintained so that light...

49 CFR 229.127 - Cab lights.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Cab lights. 229.127 Section 229.127 Transportation... lights. (a) Each locomotive shall have cab lights which will provide sufficient illumination for the... normal positions in the cab. These lights shall be located, constructed, and maintained so that light...

Light-dependent magnetoreception: orientation behaviour of migratory birds under dim red light.

PubMed

Wiltschko, Roswitha; Munro, Ursula; Ford, Hugh; Stapput, Katrin; Wiltschko, Wolfgang

2008-10-01

Magnetic compass orientation in migratory birds has been shown to be based on radical pair processes and to require light from the short wavelength part of the spectrum up to 565 nm Green. Under dim red light of 645 nm wavelength and 1 mW m(-2) intensity, Australian silvereyes and European robins showed a westerly tendency that did not change between spring and autumn, identifying it as a 'fixed direction' response. A thorough analysis revealed that this orientation did not involve the inclination compass, but was a response based on the polarity of the magnetic field. Furthermore, in contrast to the orientation under short-wavelength light, it could be disrupted by local anaesthesia of the upper beak where iron-containing receptors are located, indicating that it is controlled by these receptors. The similarity of the response under dim red light to the response in total darkness suggests that the two responses may be identical. These findings indicate that the observed 'fixed direction' response under dim red light is fundamentally different from the normal compass orientation, which is based on radical pair processes.

National Synchrotron Light Source

ScienceCinema

BNL

2017-12-09

A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

High efficiency incandescent lighting

DOEpatents

Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

2014-09-02

Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

19. INTERIOR OF KITCHEN SHOWING 2LIGHT OVER 2LIGHT, DOUBLEHUNG, WOODFRAMED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

19. INTERIOR OF KITCHEN SHOWING 2-LIGHT OVER 2-LIGHT, DOUBLE-HUNG, WOOD-FRAMED WINDOW. VIEW TO EAST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

75 FR 11920 - General Electric Lighting-Ravenna Lamp Plant, Lighting Division, Including On-Site Leased Workers...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-12

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-71,767] General Electric Lighting-Ravenna Lamp Plant, Lighting Division, Including On-Site Leased Workers from Devore Technologies, Ravenna..., 2009, applicable to workers of General Electric Lighting-Ravenna Lamp Plant, Lighting Division...

Biomaterials in light amplification

NASA Astrophysics Data System (ADS)

Mysliwiec, Jaroslaw; Cyprych, Konrad; Sznitko, Lech; Miniewicz, Andrzej

2017-03-01

Biologically produced or inspired materials can serve as optical gain media, i.e. they can exhibit the phenomenon of light amplification. Some of these materials, under suitable dye-doping and optical pumping conditions, show lasing phenomena. The emerging branch of research focused on obtaining lasing action in highly disordered and highly light scattering materials, i.e. research on random lasing, is perfectly suited for biological materials. The use of biomaterials in light amplification has been extensively reported in the literature. In this review we attempt to report on progress in the development of biologically derived systems able to show the phenomena of light amplification and random lasing together with the contribution of our group to this field. The rich world of biopolymers modified with molecular aggregates and nanocrystals, and self-organized at the nanoscale, offers a multitude of possibilities for tailoring luminescent and light scattering properties that are not easily replicated in conventional organic or inorganic materials. Of particular importance and interest are light amplification and lasing, or random lasing studies in biological cells and tissues. In this review we will describe nucleic acids and their complexes employed as gain media due to their favorable optical properties and ease of manipulation. We will report on research conducted on various biomaterials showing structural analogy to nucleic acids such as fluorescent proteins, gelatins in which the first distributed feedback laser was realized, and also amyloids or silks, which, due to their dye-doped fiber-like structure, allow for light amplification. Other materials that were investigated in that respect include polysaccharides, like starch exhibiting favorable photostability in comparison to other biomaterials, and chitosan, which forms photonic crystals or cellulose. Light amplification and random lasing was not only observed in processed biomaterials but also in living

33 CFR 127.109 - Lighting systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Lighting systems. 127.109 Section... Waterfront Facilities Handling Liquefied Natural Gas § 127.109 Lighting systems. (a) The marine transfer area for LNG must have a lighting system and separate emergency lighting. (b) All outdoor lighting must be...

33 CFR 127.109 - Lighting systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Lighting systems. 127.109 Section... Waterfront Facilities Handling Liquefied Natural Gas § 127.109 Lighting systems. (a) The marine transfer area for LNG must have a lighting system and separate emergency lighting. (b) All outdoor lighting must be...

33 CFR 127.109 - Lighting systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Lighting systems. 127.109 Section... Waterfront Facilities Handling Liquefied Natural Gas § 127.109 Lighting systems. (a) The marine transfer area for LNG must have a lighting system and separate emergency lighting. (b) All outdoor lighting must be...

33 CFR 127.109 - Lighting systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Lighting systems. 127.109 Section... Waterfront Facilities Handling Liquefied Natural Gas § 127.109 Lighting systems. (a) The marine transfer area for LNG must have a lighting system and separate emergency lighting. (b) All outdoor lighting must be...

33 CFR 127.109 - Lighting systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Lighting systems. 127.109 Section... Waterfront Facilities Handling Liquefied Natural Gas § 127.109 Lighting systems. (a) The marine transfer area for LNG must have a lighting system and separate emergency lighting. (b) All outdoor lighting must be...

14 CFR 27.1383 - Landing lights.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing lights. 27.1383 Section 27.1383... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 25.1383 - Landing lights.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing lights. 25.1383 Section 25.1383... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1383 Landing lights. (a) Each landing light...) The pilot is not adversely affected by halation; and (3) It provides enough light for night landing...

14 CFR 29.1383 - Landing lights.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing lights. 29.1383 Section 29.1383... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 29.1383 - Landing lights.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Landing lights. 29.1383 Section 29.1383... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 27.1383 - Landing lights.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Landing lights. 27.1383 Section 27.1383... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 25.1383 - Landing lights.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Landing lights. 25.1383 Section 25.1383... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1383 Landing lights. (a) Each landing light...) The pilot is not adversely affected by halation; and (3) It provides enough light for night landing...

14 CFR 29.1383 - Landing lights.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Landing lights. 29.1383 Section 29.1383... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 29.1383 - Landing lights.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Landing lights. 29.1383 Section 29.1383... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 25.1383 - Landing lights.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Landing lights. 25.1383 Section 25.1383... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1383 Landing lights. (a) Each landing light...) The pilot is not adversely affected by halation; and (3) It provides enough light for night landing...

14 CFR 27.1383 - Landing lights.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Landing lights. 27.1383 Section 27.1383... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 29.1383 - Landing lights.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Landing lights. 29.1383 Section 29.1383... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 27.1383 - Landing lights.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Landing lights. 27.1383 Section 27.1383... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 27.1383 - Landing lights.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Landing lights. 27.1383 Section 27.1383... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1383 Landing lights. (a) Each required landing or hovering light must be approved. (b) Each landing light must be installed so that— (1) No...

14 CFR 25.1383 - Landing lights.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Landing lights. 25.1383 Section 25.1383... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1383 Landing lights. (a) Each landing light...) The pilot is not adversely affected by halation; and (3) It provides enough light for night landing...

14 CFR 25.1383 - Landing lights.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Landing lights. 25.1383 Section 25.1383... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1383 Landing lights. (a) Each landing light...) The pilot is not adversely affected by halation; and (3) It provides enough light for night landing...

VALIDITATION OF A LIGHT QUESTIONNAIRE WITH REAL-LIFE PHOTOPIC ILLUMINANCE MEASUREMENTS: THE HARVARD LIGHT EXPOSURE ASSESSMENT QUESTIONNAIRE

PubMed Central

Bajaj, Archna; Rosner, Bernard; Lockley, Steven; Schernhammer, Eva S.

2011-01-01

Background Light exposure at night is now considered a probable carcinogen. To study the effects of light on chronic diseases like cancer, methods to measure light exposure in large observational studies are needed. We aimed to investigate the validity of self-reported current light exposure. Methods We developed a self-administered semiquantitative light questionnaire, the Harvard Light Exposure Assessment (H-LEA) questionnaire, and compared photopic scores derived from this questionnaire with actual photopic and circadian measures obtained from a real-life 7-day light meter application among 132 women (85 rotating night shift workers and 47 day workers) participating in the Nurses' Health Study II. Results After adjustment for age, BMI, collection day, and night work status, the overall partial Spearman correlation between self-report of light exposure and actual photopic light measurements was 0.72 (P<0.001; Kendall τ =0.57) and 0.73 (P<0.0001; Kendall τ =0.58) when correlating circadian light measurements. There were only minimal differences in accuracy of self-report of light exposure and photopic or circadian light measurement between day (r=0.77 and 0.78, respectively) and rotating night shift workers (r=0.68 and 0.69, respectively). Conclusions The results of this study provide evidence of the criterion validity of self-reported light exposure using the H-LEA questionnaire. Impact: This questionnaire is a practical method of assessing light exposure in large scale epidemiologic studies. PMID:21737411

Colored lenses suppress blue light-emitting diode light-induced damage in photoreceptor-derived cells.

PubMed

Hiromoto, Kaho; Kuse, Yoshiki; Tsuruma, Kazuhiro; Tadokoro, Nobuyuki; Kaneko, Nobuyuki; Shimazawa, Masamitsu; Hara, Hideaki

2016-03-01

Blue light-emitting diodes (LEDs) in liquid crystal displays emit high levels of blue light, exposure to which is harmful to the retina. Here, we investigated the protective effects of colored lenses in blue LED light-induced damage to 661W photoreceptor-derived cells. We used eight kinds of colored lenses and one lens that reflects blue light. Moreover, we evaluated the relationship between the protective effects of the lens and the transmittance of lens at 464 nm. Lenses of six colors, except for the SY, PN, and reflective coating lenses, strongly decreased the reduction in cell damage induced by blue LED light exposure. The deep yellow lens showed the most protective effect from all the lenses, but the reflective coating lens and pink lens did not show any effects on photoreceptor-derived cell damage. Moreover, these results were correlated with the lens transmittance of blue LED light (464 nm). These results suggest that lenses of various colors, especially deep yellow lenses, may protect retinal photoreceptor cells from blue LED light in proportion to the transmittance for the wavelength of blue LED and the suppression of reactive oxygen species production and cell damage.

33. INTERIOR OF BEDROOM NO. 4 SHOWING 1LIGHT OVER 1LIGHT, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. INTERIOR OF BEDROOM NO. 4 SHOWING 1-LIGHT OVER 1-LIGHT, DOUBLE-HUNG WINDOWS. VIEW TO NORTHWEST. - Bishop Creek Hydroelectric System, Plant 6, Cashbaugh-Kilpatrick House, Bishop Creek, Bishop, Inyo County, CA

Retinal light toxicity

PubMed Central

Youssef, P N; Sheibani, N; Albert, D M

2011-01-01

The ability of light to enact damage on the neurosensory retina and underlying structures has been well understood for hundreds of years. While the eye has adapted several mechanisms to protect itself from such damage, certain exposures to light can still result in temporal or permanent damage. Both clinical observations and laboratory studies have enabled us to understand the various ways by which the eye can protect itself from such damage. Light or electromagnetic radiation can result in damage through photothermal, photomechanical, and photochemical mechanisms. The following review seeks to describe these various processes of injury and many of the variables, which can mitigate these modes of injury. PMID:21178995

Light-weight plastination.

PubMed

Steinke, Hanno; Rabi, Suganthy; Saito, Toshiyuki; Sawutti, Alimjan; Miyaki, Takayoshi; Itoh, Masahiro; Spanel-Borowski, Katharina

2008-11-20

Plastination is an excellent technique which helps to keep the anatomical specimens in a dry, odourless state. Since the invention of plastination technique by von Hagens, research has been done to improve the quality of plastinated specimens. In this paper, we have described a method of producing light-weight plastinated specimens using xylene along with silicone and in the final step, substitute xylene with air. The finished plastinated specimens were light-weight, dry, odourless and robust. This method requires less use of resin thus making the plastination technique more cost-effective. The light-weight specimens are easy to carry and can easily be used for teaching.

AUTOMATIC LIGHT CONTROL

DOEpatents

Artzt, M.

1957-08-27

A control system for a projection kinescope used in a facsimile scanning system and, in particular, meams for maintaining substantially constant the light emanating from the flying spot on the face of the kinescope are described. In general, the invention provides a feeler member disposed in such a position with respect to a projecting lens as to intercept a portion of the light striking the lens. Suitable circuitry in conjunction with a photomultiplier tube provides a signal proportional to the light intensity of the flying spot. The grid bias on the kinescope is controlled by this signal to maintain the intensity of the spot substantially constant.

Light Pollution - An international perspective

NASA Astrophysics Data System (ADS)

Wainscoat, Richard J.

2018-01-01

The CIE (Commission Internationale de l'Eclairage, or International Commission on Illumination) is the international organization devoted to worldwide cooperation and the exchange of information on all matters relating to the science and art of light and lighting, colour and vision, photobiology and image technology. Its actions and recommendations affect lighting worldwide, and artifiical lighitng has a profound impact on ground-based astronomy. The CIE establishes Technical Committees to research speicific aspects of lighting. The CIE will hold its biannual meeting in October 2017 in South Korea. I will report on astronomy and light pollution related information from that meeting.

Direct measurement of light waves.

PubMed

Goulielmakis, E; Uiberacker, M; Kienberger, R; Baltuska, A; Yakovlev, V; Scrinzi, A; Westerwalbesloh, Th; Kleineberg, U; Heinzmann, U; Drescher, M; Krausz, F

2004-08-27

The electromagnetic field of visible light performs approximately 10(15) oscillations per second. Although many instruments are sensitive to the amplitude and frequency (or wavelength) of these oscillations, they cannot access the light field itself. We directly observed how the field built up and disappeared in a short, few-cycle pulse of visible laser light by probing the variation of the field strength with a 250-attosecond electron burst. Our apparatus allows complete characterization of few-cycle waves of visible, ultraviolet, and/or infrared light, thereby providing the possibility for controlled and reproducible synthesis of ultrabroadband light waveforms.

Light-Emitting Diode (LED) Traps Improve the Light-Trapping of Anopheline Mosquitoes.

PubMed

Costa-Neta, B M; da Silva, A A; Brito, J M; Moraes, J L P; Rebêlo, J M M; Silva, F S

2017-11-07

Numerous advantages over the standard incandescent lamp favor the use of light-emitting diodes (LEDs) as an alternative and inexpensive light source for sampling medically important insects in surveillance studies. Previously published studies examined the response of mosquitoes to different wavelengths, but data on anopheline mosquito LED attraction are limited. Center for Disease Control and Prevention-type light traps were modified by replacing the standard incandescent lamp with 5-mm LEDs, one emitting at 520 nm (green) and the other at 470 nm (blue). To test the influence of moon luminosity on LED catches, the experiments were conducted during the four lunar phases during each month of the study period. A total of 1,845 specimens representing eight anopheline species were collected. Anopheles (Nyssorhynchus) evansae (35.2%) was the most frequently collected, followed by An. (Nys.) triannulatus (21.9%), An. (Nys.) goeldii (12.9%), and An. (Nys.) argyritarsis (11.5%). The green LED was the most attractive light source, accounting for 43.3% of the individuals collected, followed by the blue (31.8%) and control (24.9%) lights. The LED traps were significantly more attractive than the control, independent of the lunar phase. Light trapping of anopheline mosquitoes was more efficient when the standard incandescent lamp was replaced with LEDs, regardless of the moon phase. The efficiency of LEDs improves light trapping results, and it is suggested that the use of LEDs as an attractant for anopheline mosquitoes should be taken into consideration when sampling anopheline mosquitoes. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Light up-conversion from near-infrared to blue using a photoresponsive organic light-emitting device

NASA Astrophysics Data System (ADS)

Chikamatsu, Masayuki; Ichino, Yoshiro; Takada, Noriyuki; Yoshida, Manabu; Kamata, Toshihide; Yase, Kiyoshi

2002-07-01

A photoresponsive organic light-emitting device combining blue-emitting organic electroluminescent (EL) diode with titanyl phthalocyanine as a near-infrared (IR) sensitive layer was fabricated. By irradiating near-IR light to the device, blue emission occurred in the lower drive voltage (between 5 and 12 V). The result indicates that the device acts as a light switch and/or an up-converter from near-IR light (1.6 eV) to blue (2.6 eV). The EL response times of rise and decay using a near-IR light trigger were 260 and 330 mus, respectively. At a higher voltage (above 12 V), enhancement of blue emission was observed with near-IR light irradiation. The ON/OFF ratio reached a maximum of 103.

Calibrating excitation light fluxes for quantitative light microscopy in cell biology

PubMed Central

Grünwald, David; Shenoy, Shailesh M; Burke, Sean; Singer, Robert H

2011-01-01

Power output of light bulbs changes over time and the total energy delivered will depend on the optical beam path of the microscope, filter sets and objectives used, thus making comparison between experiments performed on different microscopes complicated. Using a thermocoupled power meter, it is possible to measure the exact amount of light applied to a specimen in fluorescence microscopy, regardless of the light source, as the light power measured can be translated into a power density at the sample. This widely used and simple tool forms the basis of a new degree of calibration precision and comparability of results among experiments and setups. Here we describe an easy-to-follow protocol that allows researchers to precisely estimate excitation intensities in the object plane, using commercially available opto-mechanical components. The total duration of this protocol for one objective and six filter cubes is 75 min including start-up time for the lamp. PMID:18974739

Lighting for Education.

ERIC Educational Resources Information Center

Ontario Ministry of Colleges and Universities, Toronto.

Some of the qualities and quantities that must be juggled to produce good lighting for educational facilities are analyzed with photographs, tables, and drawings. The three categories of lamps used for school lighting (incandescent, fluorescent, and high intensity discharge) are described; a lamp selection guide gives the design characteristics of…

Light organ symbioses in fishes.

PubMed

Haygood, M G

1993-01-01

Most bioluminescent fishes are self-luminescent, but a substantial minority of bioluminescent teleosts produce light that is due to symbiotic luminous bacteria housed in elaborate light organs. The majority of symbiotically bioluminescent fishes (ten families in five orders) harbors common free-living species of marine luminous bacteria: Photobacterium phosphoreum, P. leiognathi, and P. fischeri (= Vibrio fischeri). Others, associated with the beryciform family Anomalopidae and nine families in the lophiiform suborder Ceratioidei, have apparently obligate symbionts that have recently been identified by small subunit (16S) rRNA analysis as new groups within the genus Vibrio. This article summarizes what is currently known about relationships between light organ symbionts and their hosts, including characteristics of light organ environments, physiology of light organ symbionts, and the evolution of light organ symbionts and their associations.

49 CFR 230.87 - Cab lights.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Cab lights. 230.87 Section 230.87 Transportation... Signals, Sanders and Lights § 230.87 Cab lights. Each steam locomotive shall have cab lights that... readings from their usual and proper positions in the cab. These lights shall be so located and constructed...

46 CFR 183.420 - Navigation lights.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Navigation lights. 183.420 Section 183.420 Shipping...) ELECTRICAL INSTALLATION Lighting Systems § 183.420 Navigation lights. All vessels must have navigation lights..., except that a vessel of more than 19.8 meters (65 feet) in length must also have navigation lights that...

46 CFR 183.430 - Portable lights

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Portable lights 183.430 Section 183.430 Shipping COAST...) ELECTRICAL INSTALLATION Lighting Systems § 183.430 Portable lights Each vessel must be equipped with at least two operable portable battery lights. One of these lights must be located at the operating station and...

49 CFR 230.87 - Cab lights.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Cab lights. 230.87 Section 230.87 Transportation... Signals, Sanders and Lights § 230.87 Cab lights. Each steam locomotive shall have cab lights that... readings from their usual and proper positions in the cab. These lights shall be so located and constructed...

46 CFR 183.420 - Navigation lights.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Navigation lights. 183.420 Section 183.420 Shipping...) ELECTRICAL INSTALLATION Lighting Systems § 183.420 Navigation lights. All vessels must have navigation lights..., except that a vessel of more than 19.8 meters (65 feet) in length must also have navigation lights that...

46 CFR 183.420 - Navigation lights.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Navigation lights. 183.420 Section 183.420 Shipping...) ELECTRICAL INSTALLATION Lighting Systems § 183.420 Navigation lights. All vessels must have navigation lights..., except that a vessel of more than 19.8 meters (65 feet) in length must also have navigation lights that...

49 CFR 230.87 - Cab lights.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Cab lights. 230.87 Section 230.87 Transportation... Signals, Sanders and Lights § 230.87 Cab lights. Each steam locomotive shall have cab lights that... readings from their usual and proper positions in the cab. These lights shall be so located and constructed...

46 CFR 183.420 - Navigation lights.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Navigation lights. 183.420 Section 183.420 Shipping...) ELECTRICAL INSTALLATION Lighting Systems § 183.420 Navigation lights. All vessels must have navigation lights..., except that a vessel of more than 19.8 meters (65 feet) in length must also have navigation lights that...

49 CFR 230.87 - Cab lights.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Cab lights. 230.87 Section 230.87 Transportation... Signals, Sanders and Lights § 230.87 Cab lights. Each steam locomotive shall have cab lights that... readings from their usual and proper positions in the cab. These lights shall be so located and constructed...

46 CFR 183.430 - Portable lights

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Portable lights 183.430 Section 183.430 Shipping COAST...) ELECTRICAL INSTALLATION Lighting Systems § 183.430 Portable lights Each vessel must be equipped with at least two operable portable battery lights. One of these lights must be located at the operating station and...

46 CFR 183.430 - Portable lights

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Portable lights 183.430 Section 183.430 Shipping COAST...) ELECTRICAL INSTALLATION Lighting Systems § 183.430 Portable lights Each vessel must be equipped with at least two operable portable battery lights. One of these lights must be located at the operating station and...

46 CFR 183.430 - Portable lights

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Portable lights 183.430 Section 183.430 Shipping COAST...) ELECTRICAL INSTALLATION Lighting Systems § 183.430 Portable lights Each vessel must be equipped with at least two operable portable battery lights. One of these lights must be located at the operating station and...

49 CFR 230.87 - Cab lights.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Cab lights. 230.87 Section 230.87 Transportation... Signals, Sanders and Lights § 230.87 Cab lights. Each steam locomotive shall have cab lights that... readings from their usual and proper positions in the cab. These lights shall be so located and constructed...

46 CFR 183.420 - Navigation lights.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Navigation lights. 183.420 Section 183.420 Shipping...) ELECTRICAL INSTALLATION Lighting Systems § 183.420 Navigation lights. All vessels must have navigation lights..., except that a vessel of more than 19.8 meters (65 feet) in length must also have navigation lights that...

46 CFR 183.430 - Portable lights

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Portable lights 183.430 Section 183.430 Shipping COAST...) ELECTRICAL INSTALLATION Lighting Systems § 183.430 Portable lights Each vessel must be equipped with at least two operable portable battery lights. One of these lights must be located at the operating station and...

Collimating lens for light-emitting-diode light source based on non-imaging optics.

PubMed

Wang, Guangzhen; Wang, Lili; Li, Fuli; Zhang, Gongjian

2012-04-10

A collimating lens for a light-emitting-diode (LED) light source is an essential device widely used in lighting engineering. Lens surfaces are calculated by geometrical optics and nonimaging optics. This design progress does not rely on any software optimization and any complex iterative process. This method can be used for any type of light source not only Lambertian. The theoretical model is based on point source. But the practical LED source has a certain size. So in the simulation, an LED chip whose size is 1 mm*1 mm is used to verify the feasibility of the model. The mean results show that the lenses have a very compact structure and good collimating performance. Efficiency is defined as the ratio of the flux in the illuminated plane to the flux from LED source without considering the lens material transmission. Just investigating the loss in the designed lens surfaces, the two types of lenses have high efficiencies of more than 90% and 99%, respectively. Most lighting area (possessing 80% flux) radii are no more than 5 m when the illuminated plane is 200 m away from the light source.

Light's Darkness

ScienceCinema

Padgett, Miles [University of Glasgow, Glasgow, Scotland

2017-12-09

Optical vortices and orbital angular momentum are currently topical subjects in the optics literature. Although seemingly esoteric, they are, in fact, the generic state of light and arise whenever three or more plane waves interfere. To be observed by eye the light must be monochromatic. Laser speckle is one such example, where the optical energy circulates around each black spot, giving a local orbital angular momentum. This talk with report three on-going studies. First, when considering a volume of interfering waves, the laser specs map out threads of complete darkness embedded in the light. Do these threads form loops? Links? Or even knots? Second, when looking through a rapidly spinning window, the image of the world on the other side is rotated: true or false? Finally, the entanglement of orbital angular momentum states means measuring how the angular position of one photons sets the angular momentum of another: is this an angular version of the EPR (Einstein, Podolsky, and Rosen) paradox?

The system analysis of light field information collection based on the light field imaging

NASA Astrophysics Data System (ADS)

Wang, Ye; Li, Wenhua; Hao, Chenyang

2016-10-01

Augmented reality(AR) technology is becoming the study focus, and the AR effect of the light field imaging makes the research of light field camera attractive. The micro array structure was adopted in most light field information acquisition system(LFIAS) since emergence of light field camera, micro lens array(MLA) and micro pinhole array(MPA) system mainly included. It is reviewed in this paper the structure of the LFIAS that the Light field camera commonly used in recent years. LFIAS has been analyzed based on the theory of geometrical optics. Meanwhile, this paper presents a novel LFIAS, plane grating system, we call it "micro aperture array(MAA." And the LFIAS are analyzed based on the knowledge of information optics; This paper proves that there is a little difference in the multiple image produced by the plane grating system. And the plane grating system can collect and record the amplitude and phase information of the field light.

Light-cone observables and gauge-invariance in the geodesic light-cone formalism

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

Scaccabarozzi, Fulvio; Yoo, Jaiyul, E-mail: fulvio@physik.uzh.ch, E-mail: jyoo@physik.uzh.ch

The remarkable properties of the geodesic light-cone (GLC) coordinates allow analytic expressions for the light-cone observables, providing a new non-perturbative way for calculating the effects of inhomogeneities in our Universe. However, the gauge-invariance of these expressions in the GLC formalism has not been shown explicitly. Here we provide this missing part of the GLC formalism by proving the gauge-invariance of the GLC expressions for the light-cone observables, such as the observed redshift, the luminosity distance, and the physical area and volume of the observed sources. Our study provides a new insight on the properties of the GLC coordinates and itmore » complements the previous work by the GLC collaboration, leading to a comprehensive description of light propagation in the GLC representation.« less

Lighting Automation Flying an Earthlike Habitat

NASA Technical Reports Server (NTRS)

Clark, Toni A.; Kolomenski, Andrei

2017-01-01

Currently, spacecraft lighting systems are not demonstrating innovations in automation due to perceived costs in designing circuitry for the communication and automation of lights. The majority of spacecraft lighting systems employ lamps or zone specific manual switches and dimmers. This type of 'hardwired' solution does not easily convert to automation. With advances in solid state lighting, the potential to enhance a spacecraft habitat is lost if the communication and automation problem is not tackled. If we are to build long duration environments, which provide earth-like habitats, minimize crew time, and optimize spacecraft power reserves, innovation in lighting automation is a must. This project researched the use of the DMX512 communication protocol originally developed for high channel count lighting systems. DMX512 is an internationally governed, industry-accepted, lighting communication protocol with wide industry support. The lighting industry markets a wealth of hardware and software that utilizes DMX512, and there may be incentive to space certify the system. Our goal in this research is to enable the development of automated spacecraft habitats for long duration missions. To transform how spacecraft lighting environments are automated, our project conducted a variety of tests to determine a potential scope of capability. We investigated utilization and application of an industry accepted lighting control protocol, DMX512 by showcasing how the lighting system could help conserve power, assist with lighting countermeasures, and utilize spatial body tracking. We hope evaluation and the demonstrations we built will inspire other NASA engineers, architects and researchers to consider employing DMX512 "smart lighting" capabilities into their system architecture. By using DMX512 we will prove the 'wheel' does not need to be reinvented in terms of smart lighting and future spacecraft can use a standard lighting protocol to produce an effective, optimized and

Lighting Automation - Flying an Earthlike Habitat

NASA Technical Reports Server (NTRS)

Clark, Tori A. (Principal Investigator); Kolomenski, Andrei

2017-01-01

Currently, spacecraft lighting systems are not demonstrating innovations in automation due to perceived costs in designing circuitry for the communication and automation of lights. The majority of spacecraft lighting systems employ lamps or zone specific manual switches and dimmers. This type of 'hardwired' solution does not easily convert to automation. With advances in solid state lighting, the potential to enhance a spacecraft habitat is lost if the communication and automation problem is not tackled. If we are to build long duration environments, which provide earth-like habitats, minimize crew time, and optimize spacecraft power reserves, innovation in lighting automation is a must. This project researched the use of the DMX512 communication protocol originally developed for high channel count lighting systems. DMX512 is an internationally governed, industry-accepted, lighting communication protocol with wide industry support. The lighting industry markets a wealth of hardware and software that utilizes DMX512, and there may be incentive to space certify the system. Our goal in this research is to enable the development of automated spacecraft habitats for long duration missions. To transform how spacecraft lighting environments are automated, our project conducted a variety of tests to determine a potential scope of capability. We investigated utilization and application of an industry accepted lighting control protocol, DMX512 by showcasing how the lighting system could help conserve power, assist with lighting countermeasures, and utilize spatial body tracking. We hope evaluation and the demonstrations we built will inspire other NASA engineers, architects and researchers to consider employing DMX512 "smart lighting" capabilities into their system architecture. By using DMX512 we will prove the 'wheel' does not need to be reinvented in terms of smart lighting and future spacecraft can use a standard lighting protocol to produce an effective, optimized and

14 CFR 27.1399 - Riding light.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 27.1399 Section 27.1399... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 25.1399 - Riding light.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 25.1399 Section 25.1399... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light for...

14 CFR 29.1399 - Riding light.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 29.1399 Section 29.1399... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 27.1399 - Riding light.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Riding light. 27.1399 Section 27.1399... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 25.1399 - Riding light.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Riding light. 25.1399 Section 25.1399... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light for...

14 CFR 29.1399 - Riding light.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Riding light. 29.1399 Section 29.1399... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 29.1399 - Riding light.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Riding light. 29.1399 Section 29.1399... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 27.1399 - Riding light.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Riding light. 27.1399 Section 27.1399... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 27.1399 - Riding light.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Riding light. 27.1399 Section 27.1399... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 25.1399 - Riding light.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Riding light. 25.1399 Section 25.1399... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light for...

14 CFR 25.1399 - Riding light.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Riding light. 25.1399 Section 25.1399... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light for...

14 CFR 29.1399 - Riding light.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Riding light. 29.1399 Section 29.1399... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 29.1399 - Riding light.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Riding light. 29.1399 Section 29.1399... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 27.1399 - Riding light.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Riding light. 27.1399 Section 27.1399... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least two...

14 CFR 25.1399 - Riding light.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Riding light. 25.1399 Section 25.1399... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light for...

GATEWAY Report Brief: OLED Lighting in the Offices of Aurora Lighting Design, Inc.

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

None, None

Summary of a GATEWAY report evaluation at the offices of Aurora Lighting Design, Inc., in Grayslake, IL, where the GATEWAY program conducted its first investigation involving OLED lighting. The project experienced several challenges, but also highlighted a number of promising attributes – which indicate that with continued improvements in efficacy, longevity, size, and flexibility, OLEDs could provide a new tool for creative and effective lighting.

Computational Modeling to Limit the Impact Displays and Indicator Lights Have on Habitable Volume Operational Lighting Constraints

NASA Technical Reports Server (NTRS)

Clark, T. A.; Salazar, G. A.; Brainard, G. C.; Litaker, H. L.; Hanifin, J.; Schwing, B. M.

2016-01-01

Even with no ambient lighting system "on", the International Space Station glows at night. The glow is caused by indicator lamps and displays that are not included with the specification of the ambient lighting system. How does this impact efforts to improve the astronaut's lighting environment to promote more effective sleep patterns? Do the extra indicators and displays add enough light to change the spectrum of light the crew sees during the day as well? If spacecraft environments are specifically engineered to have an ambient lighting system that emits a spectrum promoting a healthy circadian response, is there a way control the impact? The goal of this project is to investigate how additional light sources, such as displays and indicators change the effective light spectrum of the architectural lighting system and how impacts can be mitigated.

Intermittent episodes of bright light suppress myopia in the chicken more than continuous bright light.

PubMed

Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank

2014-01-01

Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10:14 light:dark cycle. Episodes of bright light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant bright light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of bright light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Compared with the reference group, exposure to continuous bright light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of bright light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1:1 or 7:7 minutes of bright light enhanced the protective effect against myopia and could fully suppress its development. The protective effect of bright light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous bright light, low frequency cycles of bright light (1:1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical studies.

22. INTERIOR OR BEDROOM NO. 1 SHOWING 1LIGHT OVER 1LIGHT, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. INTERIOR OR BEDROOM NO. 1 SHOWING 1-LIGHT OVER 1-LIGHT, DOUBLE-HUNG WINDOW ON EAST WALL. VIEW TO SOUTHEAST. - Bishop Creek Hydroelectric System, Plant 6, Cashbaugh-Kilpatrick House, Bishop Creek, Bishop, Inyo County, CA

Light respiration by subtropical seaweeds.

PubMed

Carvalho, Matheus C; Eyre, Bradley D

2017-06-01

Here, we report the first-ever measurements of light CO 2 respiration rate (CRR) by seaweeds. We measured the influence of temperature (15-25°C) and light (irradiance from 60 to 670 μmol · m -2  · s -1 ) on the light CCR of two subtropical seaweed species, and measured the CRR of seven different seaweed species under the same light (150 μmol · m -2  · s -1 ) and temperature (25°C). There was little effect of irradiance on light CRR, but there was an effect of temperature. Across the seven species light CRR was similar to OCR (oxygen consumption rate in the dark), with the exception of a single species. The outlier species was a coralline alga, and the higher light CRR was probably driven by calcification. CRR could be estimated from OCR, as well as carbon photosynthetic rates from oxygen photosynthetic rates, which suggests that previous studies have probably provided good estimations of gross photosynthesis for seaweeds. © 2017 Phycological Society of America.

Angle-resolved light scattering of individual rod-shaped bacteria based on Fourier transform light scattering

NASA Astrophysics Data System (ADS)

Jo, Youngju; Jung, Jaehwang; Lee, Jee Woong; Shin, Della; Park, Hyunjoo; Nam, Ki Tae; Park, Ji-Ho; Park, Yongkeun

2014-05-01

Two-dimensional angle-resolved light scattering maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform light scattering techniques, the light scattering patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from -70° to 70°. The measured light scattering patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic light scattering. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in light scattering within bacterial species is related to the cellular dry mass and growth.

Automatic Mechetronic Wheel Light Device

DOEpatents

Khan, Mohammed John Fitzgerald

2004-09-14

A wheel lighting device for illuminating a wheel of a vehicle to increase safety and enhance aesthetics. The device produces the appearance of a "ring of light" on a vehicle's wheels as the vehicle moves. The "ring of light" can automatically change in color and/or brightness according to a vehicle's speed, acceleration, jerk, selection of transmission gears, and/or engine speed. The device provides auxiliary indicator lights by producing light in conjunction with a vehicle's turn signals, hazard lights, alarm systems, and etc. The device comprises a combination of mechanical and electronic components and can be placed on the outer or inner surface of a wheel or made integral to a wheel or wheel cover. The device can be configured for all vehicle types, and is electrically powered by a vehicle's electrical system and/or battery.

Spectrally balanced chromatic landing approach lighting system

NASA Technical Reports Server (NTRS)

Chase, W. D. (Inventor)

1981-01-01

Red warning lights delineate the runway approach with additional blue lights juxtaposed with the red lights such that the red lights are chromatically balanced. The red/blue point light sources result in the phenomenon that the red lights appear in front of the blue lights with about one and one-half times the diameter of the blue. To a pilot observing these lights along a glide path, those red lights directly below appear to be nearer than the blue lights. For those lights farther away seen in perspective at oblique angles, the red lights appear to be in a position closer to the pilot and hence appear to be above the corresponding blue lights. This produces a very pronounced three dimensional effect referred to as chromostereopsis which provides valuable visual cues to enable the pilot to perceive his actual position above the ground and the actual distance to the runway.

Final Report DOE SSL Grant (No. DE-EE0006673) Advanced Light Extraction Structure for OLED Lighting

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

Cooper, Gregory; Monickam, Selina

The innovation proposed in this grant is to demonstrate a novel internal light extraction (ILE) design that can maximize the energy efficiency of Organic Light Emitting Diode (OLED) lighting devices without negatively impacting the device voltage, efficacy or angular color dependences. Even though, OLEDs have unique features compared to its inorganic counterparts, LEDs, in terms of technology development and market readiness levels, it still lags LEDs by several years. The main challenges as identified in the National Research Council’s 2013 Assessment on Solid State Lighting, are the cost of the materials and the low light extraction efficacy [1]. Improving themore » light extraction will improve both the $/Klm and lm/W, two important metrics DOE uses to measure the cost effectiveness of a light source.« less

Nonclassical light in interferometric measurements

NASA Technical Reports Server (NTRS)

Ansari, N. A.; Difiore, L.; Romano, R.; Solimeno, S.; Zaccaria, F.; Manko, Margarita A.; Manko, Vladimir I.

1995-01-01

It is shown that the even and odd coherent light and other nonclassical states of light like superposition of coherent states with different phases may replace the squeezed light in an interferometric gravitational wave detector to increase its sensitivity.

The Switch from Low-Pressure Sodium to Light Emitting Diodes Does Not Affect Bat Activity at Street Lights

PubMed Central

Rowse, Elizabeth G.; Harris, Stephen; Jones, Gareth

2016-01-01

We used a before-after-control-impact paired design to examine the effects of a switch from low-pressure sodium (LPS) to light emitting diode (LED) street lights on bat activity at twelve sites across southern England. LED lights produce broad spectrum ‘white’ light compared to LPS street lights that emit narrow spectrum, orange light. These spectral differences could influence the abundance of insects at street lights and thereby the activity of the bats that prey on them. Most of the bats flying around the LPS lights were aerial-hawking species, and the species composition of bats remained the same after the switch-over to LED. We found that the switch-over from LPS to LED street lights did not affect the activity (number of bat passes), or the proportion of passes containing feeding buzzes, of those bat species typically found in close proximity to street lights in suburban environments in Britain. This is encouraging from a conservation perspective as many existing street lights are being, or have been, switched to LED before the ecological consequences have been assessed. However, lighting of all spectra studied to date generally has a negative impact on several slow-flying bat species, and LED lights are rarely frequented by these ‘light-intolerant’ bat species. PMID:27008274

Unique Lighting Handbook.

ERIC Educational Resources Information Center

Edmund Scientific Co., Barrington, NJ.

For those who wish to enter the world of light shows, this handbook provides facts, ideas, techniques, suggestions, and sources for the many hard-to-get materials and products. Blacklight, flashing light, musicvision, and lumia (the anti-shape) are discussed. Instructions are given on how to create special effects with overhead projectors, 35mm.…

Daytime exposure to bright light, as compared to dim light, decreases sleepiness and improves psychomotor vigilance performance.

PubMed

Phipps-Nelson, Jo; Redman, Jennifer R; Dijk, Derk-Jan; Rajaratnam, Shantha M W

2003-09-01

This study examined the effects of bright light exposure, as compared to dim light, on daytime subjective sleepiness, incidences of slow eye movements (SEMs), and psychomotor vigilance task (PVT) performance following 2 nights of sleep restriction. The study had a mixed factorial design with 2 independent variables: light condition (bright light, 1,000 lux; dim light, < 5 lux) and time of day. The dependent variables were subjective sleepiness, PVT performance, incidences of SEMs, and salivary melatonin levels. Sleep research laboratory at Monash University. Sixteen healthy adults (10 women and 6 men) aged 18 to 35 years (mean age 25 years, 3 months). Following 2 nights of sleep restriction (5 hours each night), participants were exposed to modified constant routine conditions. Eight participants were exposed to bright light from noon until 5:00 pm. Outside the bright light exposure period (9:00 am to noon, 5:00 pm to 9:00 pm) light levels were maintained at less than 5 lux. A second group of 8 participants served as controls for the bright light exposure and were exposed to dim light throughout the entire protocol. Bright light exposure reduced subjective sleepiness, decreased SEMs, and improved PVT performance compared to dim light. Bright lights had no effect on salivary melatonin. A significant positive correlation between PVT reaction times and subjective sleepiness was observed for both groups. Changes in SEMs did not correlate significantly with either subjective sleepiness or PVT performance. Daytime bright light exposure can reduce the impact of sleep loss on sleepiness levels and performance, as compared to dim light. These effects appear to be mediated by mechanisms that are separate from melatonin suppression. The results may assist in the development of treatments for daytime sleepiness.

33 CFR 118.60 - Characteristics of lights.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Characteristics of lights. 118.60... LIGHTING AND OTHER SIGNALS § 118.60 Characteristics of lights. All lights required or authorized under this.... Lights must meet the requirements of this part. Lights shall be fixed lights excepting as provided in...

33 CFR 118.60 - Characteristics of lights.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Characteristics of lights. 118.60... LIGHTING AND OTHER SIGNALS § 118.60 Characteristics of lights. All lights required or authorized under this.... Lights must meet the requirements of this part. Lights shall be fixed lights excepting as provided in...