自動車用赤色 LED 灯体の不快グレア評価予測

A phosphor converted RED light for automotive LED rear lamp and compliance with ECE light regulation

BackgroundThe production of tropane alkaloids such as atropine and scopolamine by chemical methods is costly. This study aimed to find a more efficient method for producing tropane alkaloids by investigating different LED light qualities and glycine treatment using leaf callus cultures of Hyoscyamus niger L. in vitro.ResultsIn this study, after producing healthy plantlets, callus induction was done in the B5 medium with 2–4-D (2,4-Dichlorophenoxyacetic acid) at 2 mg L−1 with BA (6-benzyl adenine) at a concentration of 1 mg L−1. The use of LED light and glycine treatments started from the callus stage, in such a way that the callus produced was placed in culture media containing different concentrations of glycine (0, 2, 4 and 8 mg L−1). They were transferred to light boxes, and light treatments were applied at 4 levels (darkness (D), white LED light (WLED), blue LED light (BLED), and red LED light (RLED)). The results demonstrate that, glycine had a significant impact on the accumulation of total carbohydrates and total amino acids, quercetin, total phenols and total flavonoids in H. niger L. callus under LED light qualities. The highest atropine was obtained under Blue LED (BLED) conditions with the glycine at mg L−1, while the highest scopolamine was observed under BLED conditions with glycine at 4 mg L−1. Also, the highest gallic acid levels (4.18 mg g−1) were observed in callus grown under BLED and RED LED (RLED) light conditions with glycine at 8 mg L−1.ConclusionIn the present study, we have developed an efficient protocol for the production of tropane alkaloids by investigating different LED light colors and glycine treatments exploiting in vitro callus cultures of H.niger. These findings could have potential applications in the pharmaceutical and food industries for efficiently producing high-valued alkaloids from the plants.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12870-025-07062-z.

This study examined the impacts of different LED spectra on the growth of in vitro cultures of Musa acuminata cv. red banana and their biochemical profile, including the antioxidant enzymes catalase and ascorbate peroxidase, photosynthetic pigment and accumulation of total carbohydrate content. The far-red LEDs significantly increase shoot elongation (10.04cm). The greatest number of shoots (2.97) and the greatest multiplication rate (80%) were obtained under the treatment with blue + red LEDs. The formation of microshoots were also enhanced by blue and white LED exposure in a range of 2-2.57 shoots per explant. Root formation was also stimulated by dichromatic blue + red (6.00) LED using MS medium with 2µM indole-3-butyric acid (IBA). The enzymes catalase and ascorbate peroxidase were significantly up-regulated by irradiation with far-red (0.11 ± 0.02 CAT, 0.18 ± 0.04 APX U/mg) and blue (0.08 ± 0.01CAT, 0.10 ± 0.01APX U/mg) LED light. Total chlorophyll (0.45 to 0.80mg/g) was elevated significantly by blue, blue + red and mint-white LED. On the other hand, carotenoids (12.08-14.61mg/g) were significantly boosted by blue + red, red and mint-white LED light. Meanwhile, porphyrin (294.10-350.57mg/g) was highly synthesised after irradiation with mint-white light. Irradiation with LED light significantly increased the accumulation of carbohydrates with the highest carbohydrate content under blue + red LED light (102.22 ± 2.46mg/g) and blue light (91.69 ± 2.10mg/g). In conclusion, these results confirm that the vegetative properties and biochemical profile of red banana in vitro are eustress response to LED spectra.

ABSTRACTThis article describes an experiment carried out to evaluate discomfort glare of nonuniformly distributed light emitting diode (LED) sources. The glare sources were created with a 4 × 4 LED panel. Twenty participants evaluated 140 lighting conditions consisting of eight nonuniformity patterns, four to five levels of luminous intensity, two levels of background luminance, and two angles above the line of sight. Some clear trends were found: discomfort glare was greater when the light source was less uniform and with higher LED luminous intensity, darker background, or a smaller angle above the line of sight. The unified glare rating (UGR) model for small glare sources (UGRsmall) was tested using the experimental data. Although the UGR model had good correlation with visual results, it underestimated perceived glare. In addition, the degree of uniformity of the glare source was found to influence the performance of UGRsmall. As nonuniformity increases, the performance of UGRsmall decreases. Three modified versions of UGRsmall were derived, where each of the proposed models better predicts discomfort glare from nonuniform raw LED glare sources.

Objective: The objective of this study was to investigate the effects of different wavelengths of LED lighting on the postharvest quality of tomatoes (Solanum lycopersicum L. cv. Zahide) during breaker harvest stages.. Material and Methods: Harvested tomato fruits were placed on 500 g polystyrene foam dishes and wrapped with stretch film. They then were stored in 4±1ºC temperature and 85-90% relative humidity for 42 days under the red (R), blue (B), green (G) and white (W) LED light conditions. The fruits stored in the dark were used as control (C). Results: R and W LED treatments increased hue angle value, yellowness index value, and fruit firmness of tomatoes Blue LED lighting, also decreased electrolyte leakage that indicates delaying senescence. It was also found that blue and red LED lighting delayed fruit decay. Conclusion: As a conclusion, it could be satated that the blue LED lighting was found to be more effective than the red, white and green LED light in maintaining the quality of the tomatoes harvested at the breaking stage.

The goal of the investigations was to find out if there is a correlation between the luminance distribution on the lens surface of projection type headlamps (e.g. maximum luminance) and the average subjective glare rating (discomfort glare) of subjects under night time traffic conditions. The luminance distributions of different projection type systems are measured with a luminance measurement system and compared concerning their characteristics. For the validation a glare rating experiment has been carried out with a standard type glare source of different size and luminance peaks similar to projection lens luminances. It was found out that for glare peaks up to a diameter of a = 2' (observation angle) the candle power of the glare source is the proper parameter to calculate the subjective glare effect. For larger sizes of the glare sources there is a dependency to the diameter of the glare source for the glare effect. So it depends on the luminance distribution of the light emitting area if the candle power of the glare source is the right parameter to describe the glare effect.

It is known that chlorophyll has the second distinct absorption peak in the vicinity of 450nm (blue light region) other than the first peak in the vicinity of 660nm (red light region) in its light absorption spectrum The blue light is also indispensable to the morphologically healthy growth plant. On the other hand, the red light contributes to the plant photosynthesis. Noticing this facts, we have developed various kind of plant growth apparatus using many pieces of blue light LED and red light LED with emission wavelength 450nm and 660nm as artificial light source. In this paper, we introduce our LED plant growth apparatus and systems named such as LED PACK, BIOLED, UNIPACK, and COMPACK with respect to their structure, function, electrical design, and characteristics.

A prediction method to identify the glare source in a window with non-uniform luminance distribution

Tinted windshield and its effects on aging drivers’ visual acuity and glare response

The previous study reported by some members of the Research Group for Glare Evaluation of Outdoor LED Light Sources established in the Illuminating Engineering Institute of Japan, showed that luminance based photometric quantities have a stronger correlation to discomfort glare evaluation than those based on equivalent veiling luminance or illuminance at the observer's eye. They proposed the m_DGI as an index to assess the degree of discomfort glare. However, the test lights that cause strong discomfort glare were not examined there.

Discomfort glare is an underutilized parameter in contemporary architectural design due to uncertainties about the meaning of existing metrics, how they should be applied and what the benefits of such analysis are. Glare is position and view direction-dependent within a space, rendering it difficult to assess compared to conventional illuminance-based metrics. This paper compares simulation results for five glare metrics under 144 clear sky conditions in three spaces in order to investigate the ability of these metrics to predict the occurrence of discomfort glare and to hence support the design of comfortable spaces. The metrics analyzed areDaylight Glare Index, CIE Glare Index, Visual Comfort Probability, Unified Glare Rating and Daylight Glare Probability. It is found that Daylight Glare Probability yields the most plausible results. In an attempt to deal with multiple positions and view directions simultaneously, the concept of an ‘adaptive zone’ is introduced within which building occupants may freely adjust their position and view in order to minimise the effect of glare. The spatial and directional extents of the adaptive zone depend on furniture layout and the freedom of occupants’ tasks. It is found that applying the adaptive zone concept to a sidelit office with manually operated venetian blinds reduces the predicted hours of intolerable discomfort glare from 735 to 18 occupied hours per year and increases the annual mean daylight availability from 40% to 72%.

LED pre-exposure shines a new light on drought tolerance complexity in lettuce (Lactuca sativa) and rocket (Eruca sativa)

The use of LED technology advances rapidly in different fields of agricultural sciences, among others to generate stimulating effects to the physiological development of exposed plants. The objective of the present study was to characterize the physiological response to photoperiod with LED light in corn plants. Four genotypes and four photoperiod treatments were evaluated with LED lighting (white, blue, green, red). The experimental design was randomly complete blocks with three repeats, the treatments were the combination of genotypes and light spectra. The response variables were: height, stem diameter, radicle length, radicle volume and leaf area. The data were analyzed by ANOVA, running a multiple comparison test of means by Tukey. The results showed similarity in the behavior of LED light in some variables, while in the genotypes there was a different interaction before each treatment. For physiological stimulation it was obtained that, blue LED improves root quality (absorbent capillaries and water storage content) in the B1G, RG and B2G genotypes, while the red LED in the WG, B1G and B2G genotypes and in the green LED the B1G, RG and B2G materials, stimulated the vegetative growth of stem in the seedling respectively.

窓からの不快グレアの評価について

Although systemic therapies are recommended for severe or recalcitrant cases of pityriasis versicolor (PV), they are not free of important side effects and drug interactions. Photodynamic therapy (PDT) utilizes the action of singlet oxygen and free radicals produced by a light-activated photosensitizer to kill viruses, bacteria, or fungi. In this study, the effect of a PDT mediated by methylene blue (MB) in PV was evaluated. Five women with PV disseminated on the back and diagnosed by fresh microscopic analysis were treated with a solution of MB (2%) applied to the PV lesions for 3minutes. Next, a red LED lamp (λ=630±5nm, 37J/cm2 ), placed 100mm from the skin for 10minutes, was applied on the dyed PV lesions. Six sessions of MB/PDT were implemented with a 2-week interval in between. Wood's lamp examination was used to monitor fungal infection at each time point. Complete cure was observed in the five women at the 4weeks post-treatment follow-up. Fluoresce images from PV lesions by Wood's lamp allowed to evaluate whether the lesions were healed or not at each time point. No patient showed relapse at the 6-month follow-up. The patients did not have any adverse effect, and good cosmetic outcome was observed. Six sessions of MB/PDT spaced at 14-day intervals are sufficient for the treatment for PV in healthy patients.