scholarly journals Ecological impacts of the LED-streetlight retrofit on insectivorous bats in Singapore

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0247900
Author(s):  
Kenneth Ee Meng Lee ◽  
W. H. Deon Lum ◽  
Joanna L. Coleman
Keyword(s):  
Light Emitting Diode ◽  
Traffic Noise ◽  
Ecological Impacts ◽  
Insectivorous Bats ◽  
Light Emitting ◽  
Bat Activity ◽  
Paired Control ◽  
The Tropics ◽  
Led Lights ◽  
Positive Effect

Cities around the world are transitioning to more efficient lighting schemes, especially retrofitting traditional, high-pressure sodium (HPS) streetlights with light-emitting diode (LED) lights. Although these initiatives aim to address the problems of urban sustainability and save money, the ecological impacts of these retrofits remain poorly understood, especially in brightly lit cities and in the tropics, where urbanisation is most rapid. We performed an experimental study of the retrofit in Singapore–focusing on insectivorous bats, whose activity we monitored acoustically along paired control (HPS-lit) and treatment (LED-lit) streets. We recorded seven species along these streets, but only obtained enough recordings to measure the effect of light type for three of them–all of which can reasonably be described as urban adapters. The strongest predictor of bat activity (an index of habitat use) was rainfall–it has a positive effect. Light type did not influence bat activity or species composition of the bat assemblage along these streets, though it did interact with the effects of rainfall and traffic noise for one bat species. Ultimately, the retrofit may be ecologically meaningless to urban-adapted, tropical insectivores that already experience high levels of light pollution as they do in Singapore. However, while our findings may appear reassuring to those concerned with such retrofits in other tropical and/or brightly-lit cities, they also highlight the contextual nature of ecological impacts. We point out that they should not be prematurely generalised to other locales and systems. In particular, they do not imply no impact on species that are less urban-adapted, and there is a clear need for further studies, for example, on responses of other foraging guilds and of bats (and insects) throughout the tropics.

scholarly journals A Randomized Controlled Trail for Comparing LED Color Temperature and Color Rendering Attributes in Different Illuminance Environments for Human-Centric Office Lighting

2021 ◽  
Vol 11 (18) ◽  
pp. 8313
Author(s):  
Sujung Lee ◽  
Heakyung C. Yoon
Keyword(s):  
Light Emitting Diode ◽  
Color Temperature ◽  
Light Emitting ◽  
Randomized Controlled ◽  
Randomized Controlled Trail ◽  
The Right ◽  
Office Lighting ◽  
Color Rendering ◽  
Led Lights ◽  
Positive Effect

In this study, two experiments were conducted to investigate the effects of the color rendering index (CRI) and correlated color temperature (CCT) of light-emitting diode (LED) lighting on office user acceptance and to explore the proper color attributes for human-centric office lighting. Experiment 1 had four LED lights, with two levels for the CRI (CRI < 80: 79, 76; or CRI ≥ 80: 83, 84) and CCT (3000 K or 6500 K) at 300 lux. In experiment 2, there were four LED lights, with several levels for the CRI (CRI < 80: 78; or CRI ≥ 80: 87, 83) and CCT (3000 K or 6500 K) at 500 lux. Ninety-six participants in experiment 1 and ninety-four participants in experiment 2 performed a reading task. The results in experiment 1 and experiment 2 showed that LEDs with lower CRI values at warm color temperatures were rated as more acceptable than LEDs with higher CRI values at warm color temperatures. However, the positive effect extended to LEDs with higher CRI values at cool temperatures but not to LEDs with lower CRI values at cool temperatures. Therefore, the findings are that LEDs with lower CRI values at warm color temperatures and LEDs with higher CRI values at cool temperatures provide the right level of color attributes for office lighting.

scholarly journals LED Lights Affecting Morphogenesis and Isosteroidal Alkaloid Contents in Fritillaria cirrhosa D. Don—An Important Chinese Medicinal Herb

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1351
Author(s):  
Chia-Chen Chen ◽  
Maw-Rong Lee ◽  
Chi-Rei Wu ◽  
Hsin-Ju Ke ◽  
Hui-Min Xie ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Light Emitting Diode ◽  
Basal Medium ◽  
Gelling Agent ◽  
Embryogenic Calli ◽  
Chinese Medicinal Herb ◽  
Light Emitting ◽  
Light Spectra ◽  
Led Lights ◽  
Fritillaria Cirrhosa

Investigations were carried out to study the effects of light-emitting diode (LED) lights on growth and development of isosteroidal alkaloids in embryogenic calli of Fritillaria cirrhosa D. Don, an important traditional Chinese medicine herb. Calli were cultured in glass bottles, each containing 100 mL of Murashige and Skoog’s basal medium supplemented with 2% sucrose and 0.4% gellan gum powder, a gelling agent. These bottles were incubated in a specially designed plant growth chamber equipped with eight different LED lights consisting of single or combinations of four different light spectra emitting blue (450 nm), green (525 nm), red (660 nm), and far-red (730 nm) light. After three months of incubation, morphological changes in embryogenic calli were recorded, and LC-MS/MS analysis of cultures was carried out for peimisine, sipeimine, peiminine, and peimine. The highest number of somatic embryos and the maximum fresh weight was recorded in calli incubated under red (9R), infrared (9IR), and a combination of red+blue+infrared (3R3B3IR), respectively, in decreasing order. The highest contents of peimisine, peiminine, and peimine were recorded under red (9R) and infrared (9IR) lights, respectively. Eight LED lights had significant effects on the morphogenesis of embryogenic calli of F. cirrhosa D. Don and contents of isosteroidal alkaloids.

scholarly journals Impedance Measures and a Mounting Technique for Drosophila: Larval Movements, Heart Rate, Imaging, and Electrophysiology

2020 ◽  
Vol 3 (1) ◽  
pp. 12
Author(s):  
Noah de Castro ◽  
Robin Lewis Cooper
Keyword(s):  
Neuromuscular Junctions ◽  
Light Emitting Diode ◽  
Bright Light ◽  
Infrared Camera ◽  
Synaptic Function ◽  
Light Emitting ◽  
The Media ◽  
Led Lights ◽  
Suitable Technique ◽  
Larval Movement

Monitoring movements of larval Drosophila with electrical detection allows one to record the behaviors without the use of lights and cameras. This is a suitable technique when studying the use of light-sensitive proteins in optogenetic studies. Electrical measures are feasible to use in determining when a larva starts to move or continues to move after a light induced activation of channelrhodopsin. We have developed a technique using an electrical measure of the media as an index of larval movement. As a proof of concept, recordings with an infrared camera of the larval movement were simultaneous made with electrical measures. The two techniques parallel each other in their ability to index larval movements. Bright light-emitting diode (LED) lights used in optogenetic experiments tend to saturate the detectors of the camera unless filters are used and different filters maybe necessary depending on the LED spectrum and sensitivity of the camera. Impedance measures are independent of the type of LED or brightness. We also assessed the use of a non-solvent based glue (3M Vetbond) to hold larvae in place while measuring synaptic function of neuromuscular junctions, cardiac function and influence of modulators, or activation of light-sensitive channels.

Discomfort glare caused by white LEDs having different spectral power distributions

2017 ◽  
Vol 50 (6) ◽  
pp. 921-936 ◽  
Author(s):  
WJ Huang ◽  
Y Yang ◽  
M Ronnier Luo
Keyword(s):  
White Light ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
White Leds ◽  
Significant Difference ◽  
Discomfort Glare ◽  
Led Lights ◽  
Green Leds

This paper describes an experiment to investigate discomfort glare caused by white light-emitting diode (LED) lights having different spectral power distributions. It included two groups: a ‘Metamerism’ group and a ‘correlated colour temperatures (CCT)’ group. In the former group, it was found that white lights at 7000 K constructed from different blue LEDs and the same red and green LEDs gave about the same glare perception. In the latter group, there was a significant difference in glare perception between white lights having different CCTs. Finally, glare models, including unified glare rating (UGR) and the newly derived QUGRspd, and mUGRspd models, were tested using the data from the experiment. All of them gave quite accurate predictions of the data.

scholarly journals Data Communication Security Issues of Wi-Fi over Li-Fi

2019 ◽  
Vol 8 (3) ◽  
pp. 1977-1981
Keyword(s):  
Light Emitting Diode ◽  
Denial Of Service ◽  
Data Communication ◽  
Electrical Signal ◽  
Visible Light Communications ◽  
Light Emitting ◽  
Security Issues ◽  
The One ◽  
Audio Video ◽  
Led Lights

Visible Light Communications (VLC) system is called Light Fidelity One such example, analog data is passed to a LED (Light-Emitting Diode) bulb (using signal processing technology), after that it transmits data (which is implanted in its beam) to the detector or photodiode. The small commutes in the brisk feeble of LED bulbs is modulated by the receiver circuit into electrical signal. The signal is then reversed into a duplex data runnel that could be recognized in the same way that of audio, video and web programs that run on devices that has internet enabled. Wi-Fi is vulnerable to breaches involving various security issues such as Rouge Access Points, Denial of Service, Wireless Trespasser, Data Interruption, End point attacks etc. To overcome such restrictions, this paper proposes application level substructure for data communication using Li-Fi (Light Fidelity) Technology. By using LED lights as a transmission medium, the indoor wireless communication is achieved in much faster rate than the one WiFi (Wireless Fidelity) can provide.

scholarly journals Phototactic Response of the Oriental Armyworm, Mythimna separata (Lepidoptera: Noctuidae), to Light-Emitting Diode Lights of Different Wavelengths

2019 ◽  
Author(s):  
Kil-Nam Kim ◽  
Hye-Sung Song ◽  
Ryong-Jin Choe ◽  
Zhi-Juan Huang ◽  
Qiu-Ying Huang ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Insect Pest ◽  
Light Trap ◽  
Mythimna Separata ◽  
Light Emitting ◽  
Led Light ◽  
Phototactic Response ◽  
Green Led ◽  
Oriental Armyworm ◽  
Led Lights

Recently, light traps using light-emitting diode (LED) lights have been applied to monitor or control insect pests. The oriental armyworm, Mythimna separata Walker, is an important insect pest that has caused damage to several cereal crops, including corn, wheat and rice. The present study aims to seek out a sensitive wavelength causing high phototactic response in M. separata. The study evaluated the phototactic responses of M. separata moths to several LED lights of different wavelengths and luminance intensities under laboratory condition. Results showed that green (520 nm) LED light resulted in significant phototactic response of M. separata moths compared to LED lights of other wavelengths. Additionally, the highest attraction rate of the moths to green LED light appeared in luminance intensity group of 200 lux compared to the other intensities groups. Experiments under optimum conditions based on the above experiments revealed that the green LED light exhibited the strongest attraction rate (64.44%) among all experimental groups. An experiment performed in a net cage also showed that green LED light resulted in the highest phototactic response of M. separata moths, 1.7 times more than a commercial black light used as control. These findings clearly demonstrate that M. separata moths have a high sensitivity to the green LED light. Therefore, a light trap equipped with green LED light could be useful for monitoring and controlling M. separata moths.

scholarly journals Joule Thief Sebagai Boost Converter Daya LED Menggunakan Sel Volta Berbasis Air Laut

2018 ◽  
Vol 4 (2) ◽  
pp. 52
Author(s):  
Anwar Mujadin ◽  
Suci Rahmatia
Keyword(s):  
Electromagnetic Field ◽  
Electric Current ◽  
Light Emitting Diode ◽  
Boost Converter ◽  
Experimental Results ◽  
Power Transfer ◽  
Light Emitting ◽  
Electric Circuits ◽  
Led Lights

<p><em>Abstrak – </em><strong>Joule-Thief adalah salah satu rangkaian listrik  untuk konservasi  energi dengan menggunakan teknis medan elektromagnetik arus transien pada sebuah coil. Sirkuit ini dioperasikan menggunakan  sebuah MOSFET sebagai saklar untuk meregenerasi  tegangan dan arus listrik dalam satuan waktu kemudian disalurkan pada beban light emitting diode (LED). Dari hasil eksperimental,  sel volta berbasis air laut dengan tegangan jepit 0.8V mampu mengaktifkan lampu LED dengan konfigurasi rangkaian serial. Hasilnya menunjukkan bahwa power transfer maksimum dari sirkuit Joule-thief sangat efektif sebagai pemasok daya beban 60 LED.</strong></p><p><strong> </strong></p><p><strong><em>Kata Kunci </em></strong><em>- <strong> </strong>Joule Thief, Boost Converter Daya LED, Sel Volta Berbasis Air Laut<strong></strong></em></p><p><em> </em></p><p><em>Abstract –</em> <strong>Joule-Thief is one of the electric circuits for conservation energy by using electromagnetic field trancient current in a coil. This circuit is operated using a MOSFET as a switch to regenerating the voltage and current flowing along the coil. The electric current accumulates in the coil then in unity of time will be supplied to the light emitting diode (LED) load. From experimental results, water sea voltaic cells based with 0.8V clamp voltage are able to activate LED lights in serial circuit configurations. The results shown that power transfer joule-thief circuit is very effective capable of supplying LED up to 60 LEDs.</strong></p><p><strong> </strong></p><p><strong><em>Keywords </em></strong><em>- Joule Thief, </em><em>Boost Converter Power LED</em><em>, </em><em>Sea-Based Voltaic Cells</em><em></em></p>

Case Study for Replacement of Conventional Lights by Led Lights

2019 ◽  
Vol 7 ◽  
pp. 44-51
Author(s):  
Indu Duwal
Keyword(s):  
Energy Saving ◽  
Energy Demand ◽  
Light Emitting Diode ◽  
Light Sources ◽  
Demand And Supply ◽  
Light Emitting ◽  
Return Of Investment ◽  
Science Group ◽  
Led Lights

With the increment in the gap between the demand and supply of energy, various alternatives for decreasing the demand of energy are major concern for the various stakeholders. In order to decrease the energy demand by lighting various energy efficient lights are available in market. However it is difficult to convince the residents to change conventional artificial light sources, since lighting system is an essential part in the building which ensures the comfort, productivity and safety of the occupants in the buildings. Among the various Light Emitting Diode (LED) lights are termed as one of the most efficient energy saving lights which aims to save almost more than 50 % of energy demand than that of CFL lights with same power of illumination. Hence, this study is carried out to calculate energy saving percentage after replacing the conventional lights like florescent, mercury lights and other forms of conventional lights by LED lights. Additionally the study also was focused to evaluate feasibility of the replacement of lights by LED lights in terms of energy saving and return of investment. The research was carried out in building used by Agrotechnology and Food Science (AFSG) science group of Wageningen University in the Netherlands. The results from the study showed that almost 50% of the energy can be saved after replacement by LED lights with around 5 years for return of investment. However, factors like 1) Number of operating hours, 2) Price of lights, 3) Energy cost, 4) Labour cost for replacement and adjustment and 5) Number of replacement and adjustment per hour are the influential features that effects in the performance of various types of lights

scholarly journals Using Social Marketing to Spur Residential Adoption of ENERGY STAR®-Certified LED Lighting

2015 ◽  
Vol 21 (2) ◽  
pp. 61-78 ◽  
Author(s):  
P. Wesley Schultz ◽  
Julie Colehour ◽  
Jill Vohr ◽  
Lara Bonn ◽  
Ashlee Bullock ◽  
...  
Keyword(s):  
Social Marketing ◽  
Light Emitting Diode ◽  
Lessons Learned ◽  
Control Group ◽  
Light Emitting ◽  
Energy Star ◽  
Led Lighting ◽  
Incandescent Bulb ◽  
Star Program ◽  
Led Lights

Recent technological advancements in lighting have produced light bulbs that are dramatically more efficient than the traditional incandescent bulb. Yet despite these benefits, the marketplace has been slow to adopt these newer and more efficient bulbs. To help facilitate this change, the Environmental Protection Agency’s ENERGY STAR program conducted a series of pilot behavior change campaigns to encourage residents to purchase and install ENERGY STAR-certified light-emitting diode (LED) lights. Campaigns were conducted with Duke Energy and Efficiency Vermont aimed at encouraging residents to purchase and install certified LED lighting in their homes. The campaigns used community-based social marketing (CBSM) as the platform for developing the overarching strategy and were developed to highlight the benefits of certified LED lights and to decrease the barriers. In Vermont, a school-based fund-raiser was used to promote certified LED bulbs, and in North Carolina, special in-store lighting events were held at Home Depot and Costco retail locations. Both programs were implemented using a control group, and quantitative outcomes were tracked. Reported results highlight the increase in sales of certified LEDs associated with the campaigns. Survey data are also reported from participants in the two campaigns, along with tests for spillover of the newly adopted behavior into other lighting purchases and behaviors. The lessons learned from these two CBSM pilots are synthesized into turnkey materials that can be adopted by other organizations looking to promote the adoption of LED lights.

Which Lighting Option Is the Best for Photography in Rhinoplasty?

2021 ◽  
Author(s):  
Rodrigo Fernández-Pellón ◽  
Meshari Saghir ◽  
Ayman Jaber ◽  
Fazil Apaydin
Keyword(s):  
Light Emitting Diode ◽  
Light Sources ◽  
Light Emitting ◽  
Direct Measurements ◽  
Significant Difference ◽  
Facial Plastic ◽  
The Subject ◽  
Led Lights ◽  
Nasal Length

AbstractPhotography for preoperative analysis and follow-up is indispensable for the facial plastic surgeon. The use of strobe flash units, light-emitting diode (LED) lamps, and their position related to axis of the patient can affect the nasal contours and nasal measurements. The aim of this study was to compare the rhinoplasty pictures taken under three different lighting settings and two different positioning at 30- and 45-degree angles, and with direct measurements taken by caliper from the subjects. Standardized rhinoplasty pictures from 10 patients were taken in frontal view in a studio. These pictures were taken under three different lighting settings: built-in flash of the camera, two strobe flashes, and two LED continuous lights placed at 30 to 45 degree angles to the patient. All the pictures were uploaded to Rhinobase 2.0. In five subjects, direct measurements were done by using a Vernier caliper and compared with the computer measurements. In this study, when comparing the light sources and the angles without taking single flash into account, no relation was found between strobe lights at 30 and 45 degrees and between LED lights at 30 and 45 degrees regarding tip width, base bony width, dorsum width, interalar width, and nasal length. However, a statistically significant difference was found when the angle was changed from 30 to 45 degrees for tip width, interalar width and nasal length. The use of two LED continuous lights or two strobe lights in a studio setting has given similar results. Changing the angles of the light sources from 30 to 45 degrees affected only the tip width and the interalar width; otherwise the rest of the nasal measurements did not show any significant changes. The pictures taken at 45-degree angles to the subject showed the closest values to the direct measurements done on the patient

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