The Lighting Upgrade

Aquatic organisms have been used to investigate the safety of chemicals worldwide. One such assessment is an algal growth inhibition test. Algal growth inhibition tests are commonly performed using a growth chamber with fluorescent lamps as the lighting source, as test guidelines require continuous uniform fluorescent illumination. However, fluorescent lamps contain mercury, which has been identified as hazardous to humans and other organisms. The Minamata Convention (adopted in 2013) requires reduction or prohibition of products containing mercury. On the other hand, light-emitting diodes do not contain mercury and provide a photosynthetically effective wavelength range of 400-700 nm which is an adequate light intensity for algal growth. Light-emitting diodes are thus preferable to fluorescent lamps as a potential light source in algal growth inhibition tests. In this study, we investigated if light-emitting diodes could be substituted for fluorescent lamps in growth inhibition studies with green alga (Pseudokirchneriella subcapitata), diatom (Navicula pelliculosa), and cyanobacteria (Anabaena flos-aquae). Algal growth inhibition tests were performed using five different chemicals known to have different modes of action and are assigned as reference substances in the test guidelines. The results of each algal test showed similar values between light-emitting diodes and fluorescent lamps in terms of conditions for the growth inhibition rate and percent inhibition in yield of each chemical. It was therefore concluded that using light-emitting diodes instead of fluorescent lamps as a lighting source had no effect on the algal growth inhibition test results.

Aquatic organisms have been used to investigate the safety of chemicals worldwide. One such assessment is an algal growth inhibition test. Algal growth inhibition tests are commonly performed using a growth chamber with fluorescent lamps as the lighting source, as test guidelines require continuous uniform fluorescent illumination. However, fluorescent lamps contain mercury, which has been identified as hazardous to humans and other organisms. The Minamata Convention (adopted in 2013) requires reduction or prohibition of products containing mercury. On the other hand, light-emitting diodes do not contain mercury and provide a photosynthetically effective wavelength range of 400–700 nm which is an adequate light intensity for algal growth. Light-emitting diodes are thus preferable to fluorescent lamps as a potential light source in algal growth inhibition tests. In this study, we investigated if light-emitting diodes could be substituted for fluorescent lamps in growth inhibition studies with green alga (Pseudokirchneriella subcapitata), diatom (Navicula pelliculosa), and cyanobacteria (Anabaena flos-aquae). Algal growth inhibition tests were performed using five different chemicals known to have different modes of action and are assigned as reference substances in the test guidelines. The results of each algal test showed similar values between light-emitting diodes and fluorescent lamps in terms of conditions for the growth inhibition rate and percent inhibition in yield of each chemical. It was therefore concluded that using light-emitting diodes instead of fluorescent lamps as a lighting source had no effect on the algal growth inhibition test results.

The exhibits on display in natural science museums today often have parallels within the historical collections carefully preserved behind the scenes. One such is the collection of William Buckland (1784-1856) in Oxford University's Museum of Natural History, amassed during the first half of the nineteenth century. As the first to hold the post of Reader (Professor) of Geology at Oxford, Buckland worked hard to develop his geological knowledge and quickly established a central place for himself in the Geological Society through his bold new theories and fieldwork. Thanks to his own collecting and numerous exchanges and gifts from individuals in his networks, he built up a diverse collection for use in his research and teaching. Through five case studies in this article I consider how Buckland's, and by extension other such collections, could be used again in teaching today, particularly with university students. This would contribute to the reinforcement of Science, Technology, Engineering and Mathematics (STEM) subjects urged by the UK government, as well as aligning with the interest in material culture current in academia (Department fo Education 2015). Historical collections abound with objects that embody multidisciplinary narratives, and as such they can play an important role in deepening students' interest in science. I also discuss additional ways that some educators are using objects in undergraduate teaching today. These are designed to transcend disciplinary approaches and promote a range of soft skills, such as confidence, inclusivity, imagination and empathy. Considered afresh, historical science collections could have increased value for museum curators and educators of all kinds.

PurposeThe purpose of this study was to investigate and document existing lighting systems and lighting levels, to compare findings to the Illuminating Engineering Society (IES) lighting standards (Rodgers, 1998) and to make lighting recommendation for energy and cost savings.Design/methodology/approachLighting examinations and field measurements were conducted at a large, existing Midwestern institutional food-service facility that has been continuously operational since 1976. Lighting levels of the dining room, checkout line, buffet, kitchen, storage room and conference room were measured and then compared to the IES lighting standards. Recommendations were then made for energy and cost savings.FindingsThe average light levels in the dining room, checkout line, buffet, storage room and conference room exceeded the industry-recommended light levels. The energy and cost savings were calculated for this study, and the energy- and cost-saving strategies recommended included delamping, replacing lamps and luminaires and installing occupancy sensors. If existing lighting can be updated in an energy- and cost-saving manner, institutional food-service facilities might be made appropriate through renovation, thus extending the life of these facilities.Practical implicationsThis study has practical implications for the many existing institutional food service facilities in workplaces across the USA that could save energy and costs through renovated lighting systems.Originality/valueThis research constitutes an in situ case study, which gathered empirical lighting data at an existing institutional food-service facility and made recommendations for lighting renovations. Although lighting systems influence dining and kitchen environments, lighting has not always been fully considered in institutional food-service facilities.

This study predicts new hybrid lighting applications for LEDs. In hybrid lighting, LEDs provide a low-energy 'standby' light level while another, more powerful, efficient light source provides light for occupied periods. Lighting controls will allow the two light sources to work together through an appropriate control strategy, typically motion-sensing. There are no technical barriers preventing the use of low through high CRI LEDs for standby lighting in many interior and exterior applications today. The total luminous efficacy of LED systems could be raised by increasing the electrical efficiency of LED drivers to the maximum practically achievable level (94%). This would increase system luminous efficacy by 20-25%. The expected market volumes for many types of LEDs should justify the evolution of new LED drivers that use highly efficient ICs and reduce parts count by means of ASICs. Reducing their electronics parts count by offloading discrete components onto integrated circuits (IC) will allow manufacturers to reduce the cost of LED driver electronics. LED luminaire manufacturers will increasingly integrate the LED driver and thermal management directly in the LED fixture. LED luminaires of the future will likely have no need for separable lamp and ballast because the equipment life of all the LED luminaire components will all be about the same (50,000 hours). The controls and communications techniques used for communicating with conventional light sources, such as dimmable fluorescent lighting, are appropriate for LED illumination for energy management purposes. DALI has been used to control LED systems in new applications and the emerging ZigBee protocol could be used for LEDs as well. Major lighting companies are already moving in this direction. The most significant finding is that there is a significant opportunity to use LEDs today for standby lighting purposes. Conventional lighting systems can be made more efficient still by using LEDs to provide a low-energy standby state when lower light levels are acceptable.

Recent studies have found that LED technology is becoming competitive for streetlight applications compared with commonly employed high-intensity discharge light sources, such as high-pressure sodium (HPS) and metal halide. The expectation is that LED street lighting technology will not only provide more efficient light distribution and increased uniformity but will also save energy and reduce maintenance costs. Seattle City Light (SCL), Washington, has a street lighting system of nearly 84,000 street and area lights that predominantly use HPS light sources. Because of the potential benefits of installing LED luminaires as replacements for these lights, SCL launched the LED Streetlight Application Assessment Project pilot study to evaluate LED luminaires for photometric performance, energy efficiency, economic performance, and other impacts on the SCL streetlight system. The project findings will be used by SCL to create a strategy for the installation of LED streetlights to develop an energy-efficient lighting system. The major elements of this project included LED luminaire selection, simulated photometric performance evaluation of selected LED products, field photometric performance evaluation at selected test sites, and economic performance evaluation in comparison with HPS luminaires. In addition, because combining LED roadway luminaires with new light control systems provides many new options to enhance overall light control, facilitate maintenance, increase luminaire life, and reduce operating costs, a preliminary review of current cutting-edge lighting control systems was conducted.

This work investigates natural light levels inside a room in Electrical & Information Engineering building, Covenant University, Ota, Ogun State, Nigeria. In order to reduce the amount of energy used on lighting, it is imperative to make the utmost use of natural daylight. The use of windows are one traditional solution, other solutions are skylights and light pipes; atria and light wells; domes and arches; structural glass which are all discussed. In high temperature regions, it is necessary to reduce the amount of sunlight entering the room because light produces heat. With the use of a Light Dependent Resistor (LDR sensor), results are presented to study the day light levels in a room by measuring the light levels at various parts of the room; by measuring the proportion of light entering through the window and measuring how the light level changes over a 24 hour period. The outcome of this work is the study and development of a system that can monitor light levels in a building. The application of this work extends to determining the period of the day when daylight is maximal in order to reduce energy cost, building an automation system for the automatic lighting of dark areas within a building as well as monitoring energy consumption used to light p a building. Further extension will be to make predictions on the natural light level based on the data available.

Notes on Contributors

Pedestrian crashes are a major concern in the Northern Territory (NT), Australia, but the factors associated with these crashes differ from those in other Australian jurisdictions. This study aims to provide a comprehensive investigation of pedestrian crashes in the NT. Using police crash records and hospitalisation data, we conducted a retrospective observational analysis. We describe crash factors and calculate standardised rate ratios to compare involvement by gender, age and Aboriginal and Torres Strait Islander status. Stepwise logistic regression was used to explore crash factors contributing to fatal and 'severe injury collision' outcomes. Male pedestrians were 1.43 times (95% CI: 1.22-1.66) more likely to be involved in crashes and 1.38 times more likely to be hospitalised (95% CI: 1.23-1.56). Across all age groups, Aboriginal and Torres Strait Islander pedestrians had higher crash involvement and fatality rates. Among those aged 35-44 years, the likelihood of being involved in a fatal crash increased 35-fold (95% CI: 8.81-305.88), while severe injury risk increased 14-fold (95% CI: 8.83-23.81). Most crashes occurred during clear weather and light traffic, on straight, flat, sealed and dry roads. Factors that influence the severity of injuries in a pedestrian crash are visibility, road speed limit and driver and pedestrian alcohol and drug use. Improving lighting on roads with speed limits ≥ 70 km/h should be prioritised, or speed limits reduced where lighting upgrades are not feasible. Keeping people safe while they are intoxicated is a priority for reducing pedestrian injuries and deaths.

Numerous efforts have been made to investigate how light source color rendition affects color preference. Though the effect of light level on color appearance (known as the Hunt effect) was found in 1952, most studies investigating color preference under light sources only employed a single illuminance level and the illuminance levels were typically between 200 and 1000 lux. This article reports two psychophysical experiments that were designed to investigate how light source color rendition affected color preference across a wide range of illuminance levels, from 20 to 15,000 lux. The observers compared the color appearance of an artwork under nine nearly metameric light stimuli with a correlated color temperature (CCT) of 3000 K at different illuminance levels. These light stimuli were carefully designed to have different abilities to enhance the chroma of red and green colors, so that they had different gamut areas R g (between 100 and 124 in Experiment 1 and between 99 and 117 in Experiment 2). It was found that the illuminance level significantly affected the observers’ judgments, with a light stimulus with a greater R g being preferred at a lower light level. The light stimuli with an R g beyond 100 were preferred at the light levels from 20 to 5000 lux, whereas those with an R g around 100 were preferred at very high light levels (i.e., 10,000 and 15,000 lux). This suggested that the preference to the stimuli with an R g beyond 100, as found in many past studies, was likely due to the relatively lower illuminance levels in comparison to the daylight illuminance levels. In addition, the calculations of the color attributes of the artwork under the preferred stimuli suggested that CIECAM02 may overestimate the effect of light level on color appearance, especially when the light level was very high, which merits further investigations.

Universal decontamination of hospital surfaces in an occupied inpatient room with a continuous 405 nm light source

Nowadays artificial light is used in many areas of human life. Dedicated lighting allows to emphasize selected features of technical and biological objects, stimulates the growth of plants or enhances the attractiveness of products or artistic works. In this paper a developed low-cost lamp with an adjustable spectrum was presented. As light sources, several LEDs of both narrow-band and wide-band spectrum were selected. A multi-channel Raspberry PI was applied for LEDs driving and ensuring the user’s interface. To properly mix light from several different LEDs, a dedicated integration sphere was used, covered with paint based on barium sulfate. Full Text: PDF ReferencesD.L. DiLaura, K.W. Houser, R.G. Mistrick, G.R. Steffy, The lighting handbook (Illuminating Engineering Society 2011). DirectLink CREE Inc, Cree® 2835 LEDs Product family datasheet, (accessed 19 February 2022). DirectLink F. Szabó, R. Kéri, J. Schanda, P. Csuti, E/ Mihálykó-Orbán, A study of preferred colour rendering of light sources: home lighting, Lighting Research and Technology (Epub ahead of print 2014). CrossRef M. Feldzensztajn, P. Wierzba, A. Mazikowski, "Examination of Spectral Properties of Medicinal Plant Leaves Grown in Different Lighting Conditions Based on Mint Cultivation", Sensors 21, 4122 (2021), CrossRef S. Barbut, "Effect of illumination source on the appearance of fresh meat cuts", Meat Science 59(2), 187 (2001), CrossRef A.J. Knulst, R. Mooijweer, F.W. Jansen, L.P. Stassen, J. Dankelman, "Indicating shortcomings in surgical lighting systems", Minim. Invasive Theor. Apllied Technol. 20(5), 267 (2011). CrossRef C.M. Browning, M. Parker, T.C. Rich, S.J. Leavesley, "Illuminating the optical properties of an LED-based spectral light source for hyperspectral endoscopy", Proc. SPIE 11636, 1163608 (2021) CrossRef H.C. Wang, Y.T. Chen, J.T. Lin, C.P. Chiang, F.H. Cheng, "Enhanced visualization of oral cavity for early inflamed tissue detection", Opt. Expr. 18 (11), 11800 (2010). CrossRef D.H. Larsen, E.J. Woltering, C.C.S. Nicole, L.M.F. Marcelis, "Response of Basil Growth and Morphology to Light Intensity and Spectrum in a Vertical Farm", Frontiers in Plant Science 11, 597906 (2020) CrossRef T. Cegielski, D. Bujalski, K. Kowalczyk, J. Gajc-Wolska, L. Hemka, Proc. Electrotechn. Inst. 63 (273), 79 (2016), CrossRef A. Mazikowski, M. Feldzensztajn, Proc. SPIE 10445, 10445OK (2017). CrossRef A. Llenas, J. Carreras, "Arbitrary spectral matching using multi-LED lighting systems", Opt. Eng. 58(3), 035105 (2019). CrossRef F.J. Burgos et al., "Image and Signal Processing", Lect. Notes Comput. Sci. 8509, 115 (2014), CrossRef M. Feldzensztajn, A. Mazikowski, "Comparison of modelling and measurement results of spectra emitted by a programmable lamp", Photon. Lett. Poland 10(2), 42 (2018), CrossRef CIE, Publication No. 127, Measurement of LEDs (Central Bureau of the CIE, Vienna, Austria, 2007). DirectLink N. Kington, B. Bugbee, A Mixture of Barilium Sulfateand White Paint is a Low-Cost Substitute Reflectance Standard for Spectralon (Utah State University, 2005), DirectLink

This paper deals with the energy savings in cap lighting system of underground coalmines using Light-Emitting Diodes based cap lamp as compared to other light sources. The purpose of the paper is to ensure numerous complex and interrelated factors that must be considered to design and implement a LED based efficient lighting system suitable for underground coalmines which will satisfy human needs for good vision and comfort. The workers of mines are very much dependent on visual cues to recognize underground mining hazards. On the other hand, illumination plays a critical role in miners' safety. Some hazards are located in the miners' peripheral field-of-view offaxis from 10° to about 60° or on-axis 0°. The objective of this paper is to enhance the visual performance using solid-state cap lamps with LEDs as compared to CFL or incandescent bulbs commonly used in miners' cap lamps. Recent research has indicated that an increased short-wavelength content of the spectral power distribution of LEDs relative to incandescent lamps improves peripheral visual performance for low-light conditions. As LED produce light at required wavelength hence less energy is consumed by the lighting fixture as compared to the white light produced by incandescent bulb or CFL. The conversion of electrical power into light power is much more in case of white and red LEDs as compare to blue one. In the present paper different issues related with incandescent bulb, CFL and solid-state LED have been discussed and their performance in respect of underground coalmines has been analyzed. Furthermore, choice of type of LED has been discussed for a lighting system designed for underground coalmines.

The light source is a critical factor when Extreme Ultra Violet Lithography (EUVL) is used. This paper shows the link between the light source and the customer's requirements. These are: Throughput, Cost of Ownership (CoO) and imaging quality (e.g. CD uniformity). Also shown is how customer requirements dictate the necessary performance specifications for light sources. To be competitive with other New Generation Lithography technologies, EUVL tools should show a potential for high throughput. This puts a high requirement on the collectable in-band power produced by an EUV source. CD control requirements, together with restrictions of reflective optics, are discussed. This means that the pulse-to-pulse repeatability, the spatial stability control and the repetition rates, must be substantially better than those of current optical systems. It is essential, in the early stages of the development of potential light sources, to understand the source limitations. It is also essential to see the way the light source or the total source/lithographic system could be improved, in the development time, to meet the lithography tool requirements. Although there are no light sources currently under development that comply with the requirements for an EUVL production tool, future improvement in the performance of light sources seems possible. This paper shows detailed analyses of the way to meet (beta) and production tool requirements, including the increase in repetition rate, for all of the sources. The decrease in energy per pulse will also be discussed. The performance requirements for the light source for the first lithographic tool, together with the timeline for its choice, will be shown.

A significant portion of Europe’s historical buildings have significant potential for energy efficiency. Social policy is typically opposed to energy retrofits because it is concerned about damaging historical or cultural sites. Contrarily, there are several approaches to energy efficiency that may be used with historic structures while also retaining the region’s architectural constraints. The findings of this study demonstrate that historical structures, which are typically not targets of energy efficiency technology because of architectural constraints on the building or in the neighbourhood, may also achieve a meaningful decrease in energy usage and GHG emissions. The significant energy-saving capability of this type of building is emphasized in the historical structure taken into consideration. The historical building object of the present study was built in the beginning of the 1900s and it was selected by the Ministry of Culture for energy efficiency improvements.