Flexible lighting distribution on “party ships”

Stage arts which take place in the extraordinary everyday life of boias-frias on the backs of trucks shed light on processes of both dilution and expansion of the scene. Here one encounters a theater of cruelty. Expanded scene. Boias-frias on stage. Life and theater make contact. In this essay, three characters are presented, each of which come to life in sugarcane fields and on the backs of trucks, on the stages of the everyday theater of boias-frias : 1) ghosts and shadows; 2) passengers on ships of folly on the green seas of sugarcane fields; and 3) agonizing and playful cattle. At the end of the essay four questions are presented in regard to the notion of an expanded scene: 1) the theater of extraordinary or astounding everyday life; 2) the ludic and agonizing experience of becoming a commodity; 3) the bodily expression of becoming bagasse; and 4) the image of the past which makes contact as a flash of lighting.

Culturally dependent human social behaviours involving artificial light usage can potentially affect light pollution patterns and thereby impact the night‐time ecology in populated areas, although to date this has not been examined globally. By analysing continuous (monthly), highly resolved, spatially explicit data on global night lights (Visible and Infrared Imaging Radiometer Suite–Day/Night Band‐VIIRS‐DNB; 2014–2019) with circular statistical techniques, we evaluated whether macro‐cultural activities involving social aggregations and the use of artificial lights shape annual lighting patterns globally. Scheduled routines associated with cultural‐specific festivities appear to be important drivers of observed seasonal patterns in urban night‐time lights. For instance, the display of Christmas lights between Christmas and Epiphany Day celebrations (December–January) coincides with the annual peak in urban night‐time light intensity in Christian countries. Analogously, night celebrations during the Holy Month of Ramadam (from May to July) or the month‐long period of Karthika Masam (from October to November) fits with annual night light peaks in Muslim and Hindu countries. Annual peaks of urban light intensity in China and Vietnam also match with Chinese and Vietnamese (Tê't) New Year celebrations (January–February). In contrast, predominantly Buddhist countries, which do not have such prominent and prolonged celebrations involving artificial lights, show a relatively uniform distribution of night light peaks throughout the annual cycle. Social behaviour and sociocultural contexts help explain how people modify the global nightscape and contribute to light pollution globally. Understanding the cultural contexts responsible for peaks in artificial light usage is an important first step if humans are to mitigate any deleterious effects associated with global increases in night‐time light pollution. Read the free Plain Language Summary for this article on the Journal blog.

With increasing concerns about light pollution and energy waste in general lighting, efficient and effective lighting techniques have become imperative. We present the design of a kind of dedicated oblique illumination (OI) system to solve the problems of light pollution and the waste of energy in general lighting. The OI system consists of an extended (actual) light source, a collimator, and a freeform reflector array. Two different layouts of the OI system are proposed for different lighting situations, and design models of the two layouts are also given by use of the Monge–Ampère equation method. Two typical lighting situations, street lighting and advertising board lighting, are given here to illustrate the proposed OI system, and characteristics of the OI system are explored. The results show the light distribution is well controlled with a pretty good optical performance and the OI system has a large tolerance to the change of intensity distribution of the light source and to the size of the light source.

TNO has developed a Radiance software model to calculate the light distribution in the greenhouse using raytracing methods, suitable for daylight and artificial lighting. The model is based on a 3D CAD (Computer aided design) model. The objective is to maximize the efficiency of the artificial lighting system (the amount of light from the bulbs reaching the crops). Raytracing is a common method to simulate the behavior of light entering a greenhouse. The calculations are based on a CIE (International commission on illumination) overcast sky. The 3D CAD model of the greenhouse is made using a standard aluminium roof system and steel superstructure of a common Venlo Type greenhouse (bay width 4.0m, section width 5.0 m). The light distribution of the brackets is provided by Lights Interaction Agro BV, based on measurements on their Papillon bracket. The vertical and horizontal light distribution in and above the greenhouse is used to find the light interception of the greenhouse. A grid of vertical measurement points are used to find the light distribution of the lighting system (using a dark sky). Special asymmetrical Papillon brackets are used to optimize the light efficiency of the greenhouse, by minimizing the lighting level on the central pathway and by minimizing the light loss through the greenhouse facade. The light interception of the Venlo type greenhouse in the CIE overcast sky is compared to the IDT (Imag/DLV/TNO) method. The IDT method is widely used in the Netherlands to evaluate the light interception of greenhouses during the design process. The calculations of the greenhouse structure and the lighting system (dark sky) are used to optimize the lighting system. Concluded is that the IDT method is comparable with the raytracing calculations. Concerning the lighting systems a improvement of 10% in lighting efficiency can be achieved using the new Papillon bracket and the asymmetrical brackets at the greenhouse facade and at the central path.

Evaluation of natural and artificial lighting in conventional and innovative residences of 'Projeto CASA', Unioeste, Cascavel Campus, Parana State. The purpose of this work was to compare the natural and artificial lighting levels in the conventional and innovative residences of 'Projeto CASA' (Center for the Analysis of Alternative Energy Systems) of Unioeste - Cascavel campus. The measures were carried out using a digital light meter, in the several rooms of the residences, at different hours of the day. It was verified that the innovative residence presented a larger uniformity in lighting distribution, being in agreement with the minimum values established in NBR 5413.

Building design should aim at achieving comfort conditions and minimizing the energy consumption. The visual comfort conditions are given as the required levels of illumination, glare avoidance and a uniform distribution of light. If the recommended values cannot be obtained by daylight; supplementary artificial lighting is needed. As the window design is the major factor affecting the visual conditions in interiors and the artificial lighting energy consumption, a detailed evaluation is needed during the design stage. This study aims to describe a method of analyzing the performance of window glazing from visual comfort and energy conservation points of view, which can be used at the design stage of buildings.

Artificial light sources, including displays and luminaires, often exhibit rapid light fluctuations called temporal light modulation (TLM). TLM can be seen as their electrical footprint. This work demonstrates that TLM can be remotely detected and used to perform in situ photometric and spectroradiometric measurements of very low light levels superimposed to intense backgrounds. Illuminance levels about 500 000 times smaller than the background were reliably measured by lock-in detection, allowing photometric measurements to be performed during daytime, even with sunny conditions. Using a new type of optical lock-in spectrometer, it becomes possible to retrieve the spectral distribution of light, based on the TLM of the light source. Spectral irradiance was measured against a background 100 times more intense. Lock-in detection is an excellent technique to perform in situ measurements of artificial light, even at very low level, in the presence of daylight and other background lights.

Oxygenic photosynthesis is responsible for most of the fixation of atmospheric CO2. The microalgal community can transport atmospheric carbon into biological cycles in which no additional CO2 is created. This represents a resource to confront the actual climate change crisis. These organisms have evolved to adapt to several environments and different spectral distribution of light that may strongly influence their metabolism. Therefore, there is a need for development of photobioreactors specialized in addressing spectral optimization. Here, a multi-scale modular photobioreactor made from standard glass materials, ad hoc light circuits, and easily accessible, small commercial devices is described. The system is suitable to manage the principal culture variables of research in bioenergetics and photosynthesis. Its performance was tested by growing four evolutionary-distant microalgal species with different endosymbiotic scenarios: Chlamydomonasreinhardtii (Archaeplastida, green primary plastid), Polytomella parva (Archaeplastida, colorless plastid), Euglena gracilis (Discoba, green secondary plastid), and Phaeodactylum tricornutum (Stramenophiles, red secondary plastid). Our results show an improvement of biomass production, as compared to the traditional flask system. The modulation of the incident light spectra allowed us to observe a far-red adaptation in Euglenagracilis with a difference on paramylon production, and it also significantly increased the maximal cell density of the diatom species under green light. Together, these confirm that for photobioreactors with artificial light, manipulation of the light spectrum is a critical parameter for controlling the optimal performance, depending on the downstream goals.

The spatial and angular emission patterns of artificial and natural light emitted, scattered, and reflected from the Earth at night are far more complex than those for scattered and reflected solar radiation during daytime. In this commentary, we use examples to show that there is additional information contained in the angular distribution of emitted light. We argue that this information could be used to improve existing remote sensing retrievals based on night lights, and in some cases could make entirely new remote sensing analyses possible. This work will be challenging, so we hope this article will encourage researchers and funding agencies to pursue further study of how multi‐angle views can be analyzed or acquired.

NOAA-21 satellite was successfully launched on November 10, 2023 and joins the SNPP and NOAA-20 missions under NOAA Joint Polar Satellite System (JPSS) to provide continuation of Earth system observations. The Visible Infrared Imaging Radiometer Suite (VIIRS) instruments onboard the SNPP, NOAA-20 and NOAA-21 satellites provide sustained long-term Earth observation data accumulating to over a decade. The unique VIIRS Day/Night Band (DNB) observations particularly have a wide range of applications such as geophysical and socio-economic studies and natural disaster assessment. As learned from SNPP and NOAA-20 DNB, there was stray light over high latitude regions (with spacecraft solar zenith angle less than 118.4 degree) in DNB images over both northern and southern hemispheres. Efforts in prelaunch preparation have been devoted to reducing NOAA-21 DNB stray light. The post-launch assessment indicates that there are traces of stray light in the NOAA-21 DNB image, but with a significant reduction in stray light magnitude in comparison with both SNPP and NOAA-20 DNB. This paper presents the development and application of stray light correction for NOAA-21 DNB. Furthermore, the spatial distribution and magnitude of DNB stray light of NOAA-21 are assessed and compared with SNPP and NOAA-20. DNB images with no major artificial or auroral lights over the northern and southern hemispheres on new moon days are selected for comparison. It is found that NOAA-21 DNB stray light over both hemispheres is reduced by ~40 to 60% (depending on the along scan zone) in comparison with NOAA-20 DNB, which confirms the effectiveness of the prelaunch efforts in reducing the NOAA-21 DNB stray light.

Daylight Factor Estimation Based on Data Sampling Using Distance Weighting

Powder ceramic phosphors are fundamental materials for solid-state lighting and have contributed to the progress of general lighting and liquid crystal displays. The development of phosphors for high-color rendering illumination, wide-gamut displays, and high-brightness illumination with laser excitation continues. In recent years, the single-particle diagnostic method, which can determine the crystal structure and composition of the particles in a synthesized mixture, without obtaining a single phase has made it possible to dramatically improve the efficiency of searching for new phosphors.In this study we established a proximity measurement method that can accurately measure the photoluminescence (PL) spectrum of single phosphor particles using a commercially available multichannel photodetector generally used for power evaluation1. In this method, optical fibers were placed at a distance of less than 1 mm from a single particle sample for measurement. The measured intensity was inversely proportional to the square of the distance. PL excitation spectrum can also be measured using a single optical fiber connected to a monochromatized Xe light source. This method allows accurate spectral calibration because no extra optical components are used. Moreover, by focusing the excitation light using an optical fiber with a spherical tip, the measurement efficiency was significantly improved. The measurement intensity was proportional to the cube of the particle diameter, and even particles as small as 1.2 μm could be measured.Furthermore, we applied the proximity method to the quantum efficiency (QE) evaluation for a single particle phosphor2. Fluorescence spectroscopy by goniometric measurement, which can accurately evaluate the quantum efficiency of powdered phosphors, has been standardized by ISO23946:2020, and thus this method was applied to the evaluation of single particle. The apparatus consisted of a sample holder, an excitation fiber, and a detection fiber. A 150 W xenon lamp was used for excitation, and a multichannel photodetector was used for detection. The sample holder was attached to a 3-axis goniometer head. The samples were rotated using a motor. The excitation fiber was placed above the sample, whereas the detection fiber was driven by a motor to change the detection angle. A single optical fiber with a spherical tip was used for the excitation. Consequently, the diameter of the excitation beam was focused to 18 μm. A single optical fiber with a core diameter of 230 μm was used for the measurement. The small hole with a diameter of 0.5 mm in the sample holder was filled with barium sulfate powder as a white standard. A single phosphor particle of the test sample was then placed on it. The distances between the tips of the excitation/detection fiber and the sample were set to 500 and 700 μm, respectively. The zenith angle and the rotation angle intervals were set so that the measurement hemisphere was evenly covered with the detection fiber core diameter. Two steps were involved in the measurement. First, the particle was aligned with the center of rotation, and the light distributions in the scattering and emission spectra of the phosphor were measured. Next, the center of rotation was moved above the barium sulfate without the phosphor particle, and the scattered light distribution of the excitation light was measured. CaSiAlN3:Eu2+ red phosphor was used as the test sample. The particle picked from the powder sample was measured. The QE was calculated from the spatially integrated spectrum. Good agreement was achieved with the value for the powder sample. K. Takahashi, et al, Jpn. J. Appl. Phys., 62, 016510 (2023)K. Takahashi, et al, ECS J. Solid State Sci.Technol., 12, 076002 （2023）

In areas with a deep floor plan, the distribution of natural light is not uniform. Consequently, relying solely on daylight may not suffice to meet the space’s lighting requirements, necessitating the use of artificial lighting in darker areas. Therefore, a lighting system is needed that not only controls the glare near the windows but also increases the light at the end of the room and provides uniform daylight. One of the widely used systems is the “light shelf”, which has three main functions: shading, increasing the depth of light penetration, and reducing glare. Review articles about light shelves were published in 2015 and 2017, while more than 80% of the studies have been carried out since 2016, and light shelves with more diverse forms and dynamic elements and many consolidations have been proposed. Therefore, there is a need for a more comprehensive review. The main question of this research is how different parameters (including climate, material, ceiling, and integrated systems) can help to increase the efficiency of light shelves. By using a systematic review, studies in the past three decades were classified in order to determine the effect of these parameters on improving lighting performance and controlling solar heat gain.

The main purpose of this research is to investigate the applicability of multi-color photodetectors for controlling the spectral distribution of LED lighting. Spectral sensitivity of various sensors in the visible region was investigated. An assessment of the possibility to control and adjust the light output of the lighting equipment in relatively narrow spectral zones has been made. The obtained results provide non-standard practical guidelines for feedback and controlling the light flow characteristics for different specialized applications.

Ground-reflected light: The invariance principle and the effect of luminaire height, emission pattern, and non-uniform albedo