Pub Date : 2024-03-28DOI: 10.1177/14771535241237096
N. Derengowski, M. Knoop, S. Völker
The non-image forming effects of light are moderated by various aspects such as dose, spectrum or temporal and spatial patterns. One of them, the spatial distribution of light within the field of view, has been scarcely researched. Although few studies suggest effects on melatonin secretion during night-time, the daytime effects remain unknown. In this project, we investigated the effect of three light directions – from above, below and the side – each illuminating different retinal regions. The luminance and the size of the light source were kept constant, thus realising the same vertical illuminance and melanopic irradiance at the eye for all scenes. Forty participants underwent a two hour protocol of cognitive tasks and subjective assessments of alertness and performance. Our results suggest stronger non-image forming-effects stimulation with lighting from above, whereas the effect of lighting from below and side differed slightly.
{"title":"The effect of light directionality on alertness and cognitive performance during post-lunch dip","authors":"N. Derengowski, M. Knoop, S. Völker","doi":"10.1177/14771535241237096","DOIUrl":"https://doi.org/10.1177/14771535241237096","url":null,"abstract":"The non-image forming effects of light are moderated by various aspects such as dose, spectrum or temporal and spatial patterns. One of them, the spatial distribution of light within the field of view, has been scarcely researched. Although few studies suggest effects on melatonin secretion during night-time, the daytime effects remain unknown. In this project, we investigated the effect of three light directions – from above, below and the side – each illuminating different retinal regions. The luminance and the size of the light source were kept constant, thus realising the same vertical illuminance and melanopic irradiance at the eye for all scenes. Forty participants underwent a two hour protocol of cognitive tasks and subjective assessments of alertness and performance. Our results suggest stronger non-image forming-effects stimulation with lighting from above, whereas the effect of lighting from below and side differed slightly.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"142 38","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140369189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-26DOI: 10.1177/14771535241237002
Karin Smolders
{"title":"Opinion: The need for intensive longitudinal data to advance translational research in the domain of light and health","authors":"Karin Smolders","doi":"10.1177/14771535241237002","DOIUrl":"https://doi.org/10.1177/14771535241237002","url":null,"abstract":"","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140378311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-26DOI: 10.1177/14771535241234053
MS Ibrahim, Wkc Yung, J. Fan
The introduction of white light-emitting diodes (LEDs) is one of the key innovations that has revolutionized the lighting industry due to its multiple benefits. Despite their advantages, there is a gap in the environmental impact information of the recently developed high-power LED products within the whole lifecycle, which is a key step to achieve sustainable and green development. This life cycle assessment (LCA) is conducted by considering the cradle-to-grave system boundary. The functional units considered are a LED and compact fluorescent lamp (CFL) of 40 million lumen-hours (lm-h) used for indoor applications over an operating time of 20 000 h. In this study, the LCA was carried out using the SimaPro software and built-in ecoinvent database V2.2 with appropriate life cycle inventory data. The analysis results indicate that: (1) the LED-package has a dominant environmental impact followed by the LED driver while the housing and corrugated-board packaging materials showed the least negative effect to the ecosystem during the manufacturing phase. On the contrary, the CFL drivers are dominant followed by the light sources in the case of CFLs. From the lifecycle stages, the usage-phase showed a predominant environmental effect, mainly due to the energy consumption and sources of energy production. (2) A scenario analysis on the sources of electricity production revealed that prospective sources (70% natural gas, 25% nuclear and 5% pumped storage) of energy production lowered the environmental impact compared to the current electricity mix. These proposed electricity generation production sources provide a 61% reduction in the global warming potential in light sources for Hong Kong.
白光发光二极管（LED）的问世是一项重要的创新技术，它的多重优势彻底改变了照明行业。尽管白光发光二极管具有诸多优点，但最近开发的大功率 LED 产品在整个生命周期内的环境影响信息仍是空白，而这正是实现可持续绿色发展的关键步骤。本生命周期评估（LCA）以 "从摇篮到坟墓 "为系统边界。本研究使用 SimaPro 软件和内置的 ecoinvent 数据库 V2.2 以及适当的生命周期清单数据进行了生命周期评估。分析结果表明(1) LED 封装对环境的影响最大，其次是 LED 驱动器，而外壳和瓦楞纸板包装材料在制造阶段对生态系统的负面影响最小。相反，慳電膽的驅動器對環境的影響最大，其次是光源。从生命周期各阶段来看，使用阶段对环境的影响最大，主要是由于能源消耗和能源生产来源。(2) 对电力生产来源的情景分析表明，与目前的电力组合相比，未来的能源生产来源（70% 天然气、25% 核能和 5% 抽水蓄能）降低了对环境的影响。這些建議的發電來源可為香港減少 61% 的光源全球暖化潛力。
{"title":"Life cycle assessment of high-power white LEDs for indoor lighting in the context of Hong Kong","authors":"MS Ibrahim, Wkc Yung, J. Fan","doi":"10.1177/14771535241234053","DOIUrl":"https://doi.org/10.1177/14771535241234053","url":null,"abstract":"The introduction of white light-emitting diodes (LEDs) is one of the key innovations that has revolutionized the lighting industry due to its multiple benefits. Despite their advantages, there is a gap in the environmental impact information of the recently developed high-power LED products within the whole lifecycle, which is a key step to achieve sustainable and green development. This life cycle assessment (LCA) is conducted by considering the cradle-to-grave system boundary. The functional units considered are a LED and compact fluorescent lamp (CFL) of 40 million lumen-hours (lm-h) used for indoor applications over an operating time of 20 000 h. In this study, the LCA was carried out using the SimaPro software and built-in ecoinvent database V2.2 with appropriate life cycle inventory data. The analysis results indicate that: (1) the LED-package has a dominant environmental impact followed by the LED driver while the housing and corrugated-board packaging materials showed the least negative effect to the ecosystem during the manufacturing phase. On the contrary, the CFL drivers are dominant followed by the light sources in the case of CFLs. From the lifecycle stages, the usage-phase showed a predominant environmental effect, mainly due to the energy consumption and sources of energy production. (2) A scenario analysis on the sources of electricity production revealed that prospective sources (70% natural gas, 25% nuclear and 5% pumped storage) of energy production lowered the environmental impact compared to the current electricity mix. These proposed electricity generation production sources provide a 61% reduction in the global warming potential in light sources for Hong Kong.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"107 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140379477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-26DOI: 10.1177/14771535241237003
Myriam Aries
{"title":"Editorial: Effects of human light exposure on beyond-vision outcomes in different types of built environments","authors":"Myriam Aries","doi":"10.1177/14771535241237003","DOIUrl":"https://doi.org/10.1177/14771535241237003","url":null,"abstract":"","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"114 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140380255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With increased consumers’ demand for safe and healthy food, LED lighting for photobiology has received wider attention. In order to prolong the preservation time of the post-harvest lettuce, this paper documents a novel light source designed for preservation based on the chlorophyll absorption spectrum. Effects of intermittent exposure (35 μmol m−2 s−1) on sensory quality and chlorophyll content in fresh lettuce were investigated during 3 days storage at 20°C ± 1°C and 60% ± 1% humidity using dark as the control. The results show that the lighting reduced the colour difference value of lettuce by 23.5% compared with the dark. The content of chlorophyll was 19.7% more than in the dark. The lighting with the novel light source inhibited the decline in the colour difference value − a/ b of lettuce and delayed the degradation of chlorophyll.
{"title":"A novel light source for post-harvest lettuce preservation based on chlorophyll absorption spectrum","authors":"Y-Y Zhu, X. Zhao, Y-D Kang, Y-Z Li, J-H Zhang, G-Y Cao","doi":"10.1177/14771535241231532","DOIUrl":"https://doi.org/10.1177/14771535241231532","url":null,"abstract":"With increased consumers’ demand for safe and healthy food, LED lighting for photobiology has received wider attention. In order to prolong the preservation time of the post-harvest lettuce, this paper documents a novel light source designed for preservation based on the chlorophyll absorption spectrum. Effects of intermittent exposure (35 μmol m−2 s−1) on sensory quality and chlorophyll content in fresh lettuce were investigated during 3 days storage at 20°C ± 1°C and 60% ± 1% humidity using dark as the control. The results show that the lighting reduced the colour difference value of lettuce by 23.5% compared with the dark. The content of chlorophyll was 19.7% more than in the dark. The lighting with the novel light source inhibited the decline in the colour difference value − a/ b of lettuce and delayed the degradation of chlorophyll.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"36 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140452719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-04DOI: 10.1177/14771535231225363
N. Isaacs
Current New Zealand (New Zealand Building Code), Australian (National Construction Code) and American (International Building Code) building codes include deemed-to-satisfy requirements for a given proportion of a house’s floor area (e.g. 10%) to be in windows. These, plus the current English Building Regulations, also require a proportion of windows to be openable (e.g. one-half or 5% of the floor area). A detailed summary table supported by code extracts is used to trace the evolution of these requirements. Even the architects of antiquity provided only rules for window proportions but not for window area or size based on room dimensions. The paper demonstrates the evolution of this 21st century requirement follows a direct line to the English 1859 model ‘ Byelaws as to New Streets and Buildings’. Prior to that date, only two rules from 1842 (room volume based) and 1734 (height and volume based) have been found which gave a required window area based on room size. It is hypothesised that one of these led to the current rules. Although the current proportion rules may be appropriate, no empirical research-based origin has been identified.
{"title":"‘The window area shall be at least one-tenth of the area of the room’: The origins of a daylight (and ventilation) requirement in modern building codes","authors":"N. Isaacs","doi":"10.1177/14771535231225363","DOIUrl":"https://doi.org/10.1177/14771535231225363","url":null,"abstract":"Current New Zealand (New Zealand Building Code), Australian (National Construction Code) and American (International Building Code) building codes include deemed-to-satisfy requirements for a given proportion of a house’s floor area (e.g. 10%) to be in windows. These, plus the current English Building Regulations, also require a proportion of windows to be openable (e.g. one-half or 5% of the floor area). A detailed summary table supported by code extracts is used to trace the evolution of these requirements. Even the architects of antiquity provided only rules for window proportions but not for window area or size based on room dimensions. The paper demonstrates the evolution of this 21st century requirement follows a direct line to the English 1859 model ‘ Byelaws as to New Streets and Buildings’. Prior to that date, only two rules from 1842 (room volume based) and 1734 (height and volume based) have been found which gave a required window area based on room size. It is hypothesised that one of these led to the current rules. Although the current proportion rules may be appropriate, no empirical research-based origin has been identified.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"6 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139866509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-04DOI: 10.1177/14771535231225363
N. Isaacs
Current New Zealand (New Zealand Building Code), Australian (National Construction Code) and American (International Building Code) building codes include deemed-to-satisfy requirements for a given proportion of a house’s floor area (e.g. 10%) to be in windows. These, plus the current English Building Regulations, also require a proportion of windows to be openable (e.g. one-half or 5% of the floor area). A detailed summary table supported by code extracts is used to trace the evolution of these requirements. Even the architects of antiquity provided only rules for window proportions but not for window area or size based on room dimensions. The paper demonstrates the evolution of this 21st century requirement follows a direct line to the English 1859 model ‘ Byelaws as to New Streets and Buildings’. Prior to that date, only two rules from 1842 (room volume based) and 1734 (height and volume based) have been found which gave a required window area based on room size. It is hypothesised that one of these led to the current rules. Although the current proportion rules may be appropriate, no empirical research-based origin has been identified.
{"title":"‘The window area shall be at least one-tenth of the area of the room’: The origins of a daylight (and ventilation) requirement in modern building codes","authors":"N. Isaacs","doi":"10.1177/14771535231225363","DOIUrl":"https://doi.org/10.1177/14771535231225363","url":null,"abstract":"Current New Zealand (New Zealand Building Code), Australian (National Construction Code) and American (International Building Code) building codes include deemed-to-satisfy requirements for a given proportion of a house’s floor area (e.g. 10%) to be in windows. These, plus the current English Building Regulations, also require a proportion of windows to be openable (e.g. one-half or 5% of the floor area). A detailed summary table supported by code extracts is used to trace the evolution of these requirements. Even the architects of antiquity provided only rules for window proportions but not for window area or size based on room dimensions. The paper demonstrates the evolution of this 21st century requirement follows a direct line to the English 1859 model ‘ Byelaws as to New Streets and Buildings’. Prior to that date, only two rules from 1842 (room volume based) and 1734 (height and volume based) have been found which gave a required window area based on room size. It is hypothesised that one of these led to the current rules. Although the current proportion rules may be appropriate, no empirical research-based origin has been identified.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"156 20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139806673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-25DOI: 10.1177/14771535231225360
RS Kore, N. Brown, D. Durmus
Light absorbed by sensitive artwork may cause irreversible damage. Optimising the spectral power distribution of light sources to minimise absorbed light can reduce damage while maintaining the colour appearance of the artwork. Previous absorption-minimisation studies used optimisation methods without comparing their performance. Here, three-channel LED-augmented reality projector spectra were optimised for 24 colour samples using a brute-force (BF) and multi-objective genetic algorithm (MOGA). The BF search and MOGA performed similarly in achieving optimal results, reducing both light absorption and energy consumption by almost half. However, MOGA was 2.5 times faster than BF in finding optimal solutions. The results indicate that an LED RGB projector can be used to illuminate museum artefacts to reduce light absorption and energy consumption, with the caveat of perceptible colour shifts in some of the colour samples. Future research will investigate observers’ subjective evaluations of artwork under optimised lighting.
{"title":"Optimising augmented reality projector light output to balance art conservation, colour quality and energy consumption","authors":"RS Kore, N. Brown, D. Durmus","doi":"10.1177/14771535231225360","DOIUrl":"https://doi.org/10.1177/14771535231225360","url":null,"abstract":"Light absorbed by sensitive artwork may cause irreversible damage. Optimising the spectral power distribution of light sources to minimise absorbed light can reduce damage while maintaining the colour appearance of the artwork. Previous absorption-minimisation studies used optimisation methods without comparing their performance. Here, three-channel LED-augmented reality projector spectra were optimised for 24 colour samples using a brute-force (BF) and multi-objective genetic algorithm (MOGA). The BF search and MOGA performed similarly in achieving optimal results, reducing both light absorption and energy consumption by almost half. However, MOGA was 2.5 times faster than BF in finding optimal solutions. The results indicate that an LED RGB projector can be used to illuminate museum artefacts to reduce light absorption and energy consumption, with the caveat of perceptible colour shifts in some of the colour samples. Future research will investigate observers’ subjective evaluations of artwork under optimised lighting.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"59 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139598453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-12DOI: 10.1177/14771535231223871
S. Turanov, A. Burenina, E. Surnina, A. Butenkova, T. Astafurova, T. Han
One of the promising irradiation modes for plant is dynamic, when parameters change throughout the growing process depending on certain factors. In this work, lettuce plants were illuminated under different LED light sources, including white (2700 K), 30% white (2700 K) + 70% red (660 nm), 15% blue (445 nm) + 85% red (660 nm), 40% blue (445 nm) + 20% red (630 nm) + 40% red (660 nm) and dynamic mode for 35 days to investigate the effects. Photosynthetically active flux density was the same for all lettuce samples during the experiment (210 µmol m−2 s−1). The results showed the effects of photoregulation on the growth and development of lettuce plants. Optimal irradiation regime for lettuce plants was a dynamic regime formed using two colour components: white (2700 K) and red (660 nm) LEDs. Lettuce grown under dynamic conditions had a lower content of nitrates and developed faster than under stationary conditions.
{"title":"Influence of dynamic LED irradiation mode on the content of nitrates, structural and functional characteristics of lettuce plants","authors":"S. Turanov, A. Burenina, E. Surnina, A. Butenkova, T. Astafurova, T. Han","doi":"10.1177/14771535231223871","DOIUrl":"https://doi.org/10.1177/14771535231223871","url":null,"abstract":"One of the promising irradiation modes for plant is dynamic, when parameters change throughout the growing process depending on certain factors. In this work, lettuce plants were illuminated under different LED light sources, including white (2700 K), 30% white (2700 K) + 70% red (660 nm), 15% blue (445 nm) + 85% red (660 nm), 40% blue (445 nm) + 20% red (630 nm) + 40% red (660 nm) and dynamic mode for 35 days to investigate the effects. Photosynthetically active flux density was the same for all lettuce samples during the experiment (210 µmol m−2 s−1). The results showed the effects of photoregulation on the growth and development of lettuce plants. Optimal irradiation regime for lettuce plants was a dynamic regime formed using two colour components: white (2700 K) and red (660 nm) LEDs. Lettuce grown under dynamic conditions had a lower content of nitrates and developed faster than under stationary conditions.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"5 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139532512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-28DOI: 10.1177/14771535231217385
Steve Fotios
{"title":"Opinion: Evidence for design guidance","authors":"Steve Fotios","doi":"10.1177/14771535231217385","DOIUrl":"https://doi.org/10.1177/14771535231217385","url":null,"abstract":"","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"220 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139152906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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