Presence Of Daylight Research Articles

Untangling light in noisy luminous environments

Electric 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 spectral quantities through the TLM of the light source. The spectral distribution of an LED lamp was measured against a daylit background more than 1500 times brighter. Lock-in detection is an excellent technique to perform in situ measurements of electric light, even at very low level, in the presence of daylight and other background lights, opening interesting opportunities to characterize anthropogenic light pollution.

The impact of daylight and window views on length of stay among patients with heart disease: A retrospective study in a cardiac intensive care unit

BackgroundHeart disease is the leading cause of death in the United States. The length of stay (LOS) is a well-established parameter used to evaluate health outcomes among critically ill patients with heart disease in cardiac intensive care units (CICUs). While evidence suggests that the presence of daylight and window views can positively influence patients’ LOS, no studies to date have differentiated the impact of daylight from window views on heart disease patients. Also, existing research studies on the impact of daylight and window views have failed to account for key clinical and demographic variables that can impact the benefit of such interventions in CICUs. MethodsThis retrospective study investigated the impact of access to daylight vs. window views on CICU patients’ LOS. The study CICU is located in a hospital in the southeast United States and has rooms of the same size with different types of access to daylight and window views, including rooms with daylight and window views (with the patient bed located parallel to full-height, south-facing windows), rooms with daylight and no window views (with the patient bed located perpendicular to the windows), and windowless rooms. Data from electronic health records (EHRs) for the time-period September 2015 to September 2019 (n=2936) were analyzed to investigate the impact of room type on patients’ CICU LOS. Linear regression models were developed for the outcome of interest, controlling for potential confounding variables. ResultsUltimately, 2319 patients were finally included in the study analysis. Findings indicated that patients receiving mechanical ventilation in rooms with access to daylight and window views had shorter LOS durations (16.8 h) than those in windowless rooms. Sensitivity analysis for a subset of patients with LOS ≤3 days revealed that parallel bed placement to the windows and providing access to both daylight and window views significantly reduced their LOS compared to windowless rooms in the unit (P=0.007). Also, parallel bed placement to the window significantly reduced LOS in this patient subset for those with an experience of delirium (P=0.019), dementia (P=0.008), anxiety history (P=0.009), obesity (P=0.003), and those receiving palliative care (P=0.006) or mechanical ventilation (P=0.033). ConclusionsFindings from this study could help architects make design decisions and determine optimal CICU room layouts. Identifying the patients who benefit most from direct access to daylight and window views may also help CICU stakeholders with patient assignments and hospital training programs.

Prototyping a Lighting Control System Using LabVIEW with Real-Time High Dynamic Range Images (HDRis) as the Luminance Sensor

Lighting control systems (LCSs) play important roles in maintaining visual comfort and energy savings in buildings. This paper presents a prototype LCS using LabVIEW with real-time high dynamic range images and a digital multiplex controller to brighten lamps sequentially to provide visual comfort. The prototype is applied to a scaled classroom model with three schemes involving different activities and needs: writing and reading, requiring a uniform luminance of approximately 100 cd/m2, teaching using a whiteboard, requiring an illuminance of approximately 120 cd/m2 for the whiteboard and 60 cd/m2 for the desks, and drawing and art activities focused on the center of the room, requiring an illuminance of approximately 100 cd/m2 for the center area and 50 cd/m2 for the background area. For each scheme, two conditions are presented: one in which the room is treated as a closed room without windows, and the one in which the room has a large window on one wall that enables daylight to penetrate the room. The prototype works well with both schemes and provides different combinations of lamp brightness levels, starting from 10% to 60%, based on the activities and required luminance, and can save around 73–82% of electricity. The presence of daylight does not always result in more energy savings, as the brightness contrast for visual comfort needs to be considered.

The response of common carp (Cyprinus carpio) to insonified bubble curtains.

Acoustic bubble curtains have been marketed as relatively low cost and easily maintained behavioural deterrents for fisheries management. Their energy efficiency can be improved by reducing air flow and exploiting bubble resonance. In a series of three flume experiments, we: (1) investigated the reactions of carp to a low air flow bubble curtain, (2) compared the effectiveness of resonant versus non-resonant insonified bubble curtains (for the same volume flux of gas injected through the nozzles) to deter passage, and determined the stimuli responsible for eliciting deterrence, and (3) included the effect of visual cues generated by the bubble curtain. This study showed that bubble curtains with a higher proportion of resonant bubbles deterred carp relatively better. Passage rejection was likely influenced by multiple cues at distances within a body length of the fish- specifically the rate of change in both particle motion and flow velocity caused by rising bubbles. All acoustic bubble curtains were less effective in the presence of daylight, suggesting that vision plays an important role at mediating carp reactions. We discuss the importance of ascertaining the bubble size distribution, in addition to the gas flow rate and aperture size, when characterising acoustically active bubble curtains.

Ethereal Hydroperoxides: Powerful Reagents for S-Oxygenation of Bridging Thiophenolate Functions

S-Oxygenation of thiophenolate bridges by ethereal hydroperoxides was studied. [NiII2LS(PhCO2)]+ (1), where LS = macrocyclic aminethiolate supporting ligand, is S-oxygenated readily in a mixed methanol/acetonitrile solution with ether/dioxygen at room temperature in the presence of daylight. The reactions were found to depend strongly on the choice of the ether. Uptake of two O atoms occurs in dioxane to give a mixed thiolate/sulfinate complex [NiII2LSO2(PhCO2)]+ (2) containing the rare five-membered Ni(μ1,1-S)(μ1,2-OS)Ni core. In tetrahydrofuran, four O atoms are taken up by 1 to generate the bis(sulfinate) species [NiII2LSO4(PhCO2)]+ (3). A mono-S-oxygenated sulfenate intermediate can be detected by electrospray ionization mass spectrometry. The oxygenation reactions proceed in high yields without complex disintegration and invariably provide μ1,2-bridging sulfinates as established by spectroscopy (IR and UV/vis), X-ray crystallography, and accompanying density functional theory calculations. The oxygenation of the S atoms has a strong impact on the electronic structures of the nickel complexes. The monosulfinate complex 2 has an S = 2 ground state resulting from moderate ferromagnetic exchange coupling interactions (J = +15.7 cm-1; H = -2JS1S2), while an antiferromagnetic exchange interaction in 3 shows the presence of a ground state with spin S = 0 (J = -0.56 cm-1).

Illuminance levels based on different sky conditions by considering daylight harvesting

Daylight Harvesting Systems (DHS) offer the most effective and significant to reduce energy consumption. In the lighting system, there are various problems which include waste of energy consumption, inappropriate lighting and increasing greenhouse effect. Therefore, the waste of energy consumption should be reduced by controlling the dimming levels of artificial lighting according to the standard thus reducing the greenhouse effect. Hence, this paper considered the daylight adaptive for the lighting system to determine the dimming level and illuminance level for the office room. The simulation has been carried out using DIALux simulation lighting software to simulate the average daylight and average illuminance level with different conditions sky, which is clear, average, and overcast sky. Based on the result, the illuminance level has complied with the European Standard EN12464-1. Furthermore, the presence of daylight and weather conditions plays an essential role in the lighting system. The illuminance and dimming levels are different depending on the time and type of sky condition at that time. Therefore, the daylight adaptive in the lighting system can reduce the use of artificial light in the room.

Short-term changes in the quality of suspended particulate matter in a human impacted and mangrove dominated tropical estuary (Can Gio, Vietnam)

Suspended particulate matter (SPM) is a key component of coastal food webs and a key variable of nutrient budgets. Understanding its variability across short time scales in estuaries may help ecologists understand seasonal and diurnal migration of estuarine organisms, and answer how their nutritional requirements are fulfilled. It may also inform biogeochemists regarding the factors that influence import and export of nutrients between terrestrial and coastal ecosystems. This study aimed to link the dynamics of fatty acids, stable isotopes (δ13C and δ15N) and C/N ratios of SPM, revealing organic matter quality, to rapidly varying factors (SPM concentration, salinity and presence of daylight) and comparing this variability to the seasonal variation induced by the alternation of dry and wet seasons in the studied region. Our results revealed that these rapidly varying factors had a strong influence on the bacterial and the phytoplanktonic compartments of SPM. They suggest that tidally resuspended particles are the site of intense heterotrophic activity and that estuarine phytoplankton store lipids during the daytime up to substantially modifying SPM quality. Our study also shows higher freshness of SPM during the wet season. We expect this study to raise the interest of both biologists and biogeochemists to introduce daily variability of SPM in food webs and nutrient budgets modelling.

Day-Lighting and Thermal Performance of a Building with a Courtyard in Composite Climate: A Case of Bhopal

Passive Design is important for the current era in the aspect of architectural and environmental friendly view of buildings. It is always considered that the principles of a good passive design suitable for your climate effectively ‘locks in’ thermal comfort, low heating and cooling bills, and reduced greenhouse gas emissions for the life span of buildings. The courtyard is suitable in almost all building typologies in various climatic zones due to its social, environmental and therapeutic potentials. The main objective of this study is to investigate the Central courtyard design of MANIT Energy Centre Bhopal in an aspect of indoor thermal comfort and presence of daylight. The courtyard configurations, courtyard orientation, and natural features like daylight, which is required for Courtyard design were investigated in a courtyard building in MANIT Energy center Bhopal. The methodology of this study involved the developing of a data chart which is based on temperature and illuminance available in four directions of the building, and the statistical description method was used to interpret and analyzed the data. The Results of this study shows that MANIT Energy Center Bhopal central courtyards buildings were designed based on a cautious consideration like orientation, configurations and natural features to enhance their effective daylight availability and passive cooling potentials. MANIT Energy center Bhopal building courtyard study concluded that it is inventively designed but future experimental studies to appraise their thermal performances is required, and optimum performance can be predicted. Therefore, further studies based on simulation are recommended.

Gender Differences in Use of a Pedestrian Crossing: An Observational Study in Newcastle upon Tyne

Evolutionary psychologists have put forward that there are evolved differences in risk taking between men and women. Potentially, these also play out in every day behaviours, such as in traffic. We hypothesised that (perceived) gender would influence using a pedestrian crossing. In addition, we also explored if a contextual factor, presence of daylight, could modify risk taking behaviour. 558 pedestrians were directly observed and their use of a crossing near a Metro station in a large city in the North East of England was coded. Using logistic regression, we found evidence that women were more inclined than men to use the crossing. We found no evidence for a contextual effect of daylight or an interaction between daylight and gender on use of the crossing. We discuss the limitations and implications of this finding with reference to literature on risk taking.

An Accurate Wearable Foot Clearance Estimation System: Toward a Real-Time Measurement System

This paper presents an accurate, robust, wearable measurement system for foot clearance estimation along with algorithms to provide a real-time estimate of foot height and orientation. Different configurations of infrared distance meter sensors were used, both alone and in combination with an inertial measurement unit. In order to accurately estimate the foot clearance when in presence of daylight and when the foot orientation changes dynamically during walking, several algorithms were designed based on physics of sensors and tuned using the acquired data against a reference system. These algorithms, specific to the number of sensors, include the estimators of the foot orientation and estimators of the foot clearance. These estimators are tested on normal walking (rms error ≤ 8.4 mm) and walking with exaggerated step heights and inversion-eversion rotations. A Bayesian fusion of estimators was also implemented to better cope with the extreme and abnormal walking kinematics while maintaining a high performance for normal walking. All estimators were trained on uniformly distributed bootstrapped sub-samples of data and tested on several normal and abnormal walking data. The results proved the robustness of the proposed system against variations in the gait kinematics ( $\vert $ mean $\vert \pm $ standard deviation of error for heel and toe clearance was equal to or smaller than 3.1±9.3 mm when using a Bayesian fusion of three different estimators) and environment lighting (with an introduced error of 1 to 4% of actual distance).

Effects of LED light spectra on lettuce growth and nutritional composition

Year-round greenhouse production in northern latitudes depends on the use of artificial lighting. Light emitting diodes provide a promising means to save energy during cultivation as well as to modify the light spectrum to regulate the growth and quality of the crop. We compared the effects of light emitting diode lighting with different spectral compositions on the growth, development and nutritional quality of lettuce ( Lactuca sativa L. ‘Frillice’). We show that warm-white and warm-white supplemented with blue spectra provide equal growth and product quality compared to conventional high-pressure sodium lighting in the absence and presence of daylight. Our data indicate that for biomass accumulation, the far-red component in the light spectrum is more critical than green light or the red/blue ratio. Furthermore, we demonstrate that a red + blue spectrum increases the concentration of several vitamins in lettuce. However, biomass accumulation using this spectrum was insufficient when daylight was excluded.

INVESTIGATING USE OF DAYLIGHT IN A TYPICAL ALGERIAN PUBLIC CLASSROOM TYPOLOGY

The presence of daylight affects human beings both physiologically and psychologically. Admitting daylight into an indoor enclosure improves mood, enhances morale, lowers fatigue, and reduces eyestrain. To adequately capture the characteristics of current daylight design practice in typical Algerian classroom A field observations was carried out in the study area which comprises the school buildings and including performing a series of measurements for daylighting inside the classrooms. This was further confirmed by the use of simulation using IES <VE> software. As investigated the standard sky condition in Algeria is overcast and based on this; the conceptual models of Algerian public schools are divided into two types of school buildings. Schools inherited from the colonial period and those built during the period of French occupation which are characterized by variation on the arrangements of classrooms even for a single school and are streamlined into; linear assembly with simple distribution (traditional classroom) which is common and the second type which has a linear assembly with double distribution. Based on the existing guideline from the Ministry of National Education which was adopted from the colonial masters. The simulation result confirm that class room typologies in Algeria had less consideration for climatic and comfort conditions and the window openings allowed excessive daylight.

Daylight Impact on Energy Performance of Internal Lighting

Daylight in interior offers a considerable contribution of energy saving, the key is to design an integrated lighting system between the electric lighting system configuration and its control strategy. An optimal lighting system has to consider the different presence of daylight in the zones to arrange the most favorable luminaires layout. An automatic control system could be employed to switch or dim selected groups of luminaires. The paper suggests a criterion to evaluate the yearly daylight impact on energy performance of internal lighting according to daylight availability, the lighting system layout, and the control system arranged. A simplified evaluation by the daylight lumen method is useful for designers to estimate the operation costs in reference to the initial costs in preliminary design.

Effect of daylight on regrowth of bacteria in anaerobically digested sludge

This study investigated the regrowth of total coliform, Salmonella, and Clostridium perfringens in anaerobically digested sludge after centrifuge dewatering in the presence and absence of daylight. Sludge cake and centrate samples were collected from a treatment plant, and half of the samples was stored in daylight and the other half was stored in dark for three weeks. The bacteria levels in the cake and centrate samples were measured periodically throughout the storage period, and all three bacteria showed substantial regrowth. Presence of daylight increased the regrowth of Salmonella both in sludge cake and centrate, and increased the regrowth of total coliform in centrate. Salmonella exhibited the highest regrowth rate in cake among the three bacteria tested both in the presence and absence of light. Daylight did not appear to have a significant impact on the regrowth of Clostridium perfringens in cake and centrate, and on the regrowth of total coliform in cake. This might, however, be caused by the masking effect of the higher initial numbers of these bacteria in the samples. There is need for more research to thoroughly understand the effect of daylight on the regrowth of sludge bacteria.

Effets de quelques prétraitements physiques sur l'amélioration des performances germinatives de Stipa tenacissima L. et caractérisation des substances inhibitrices

The oldest caryopses of alfa (9 years) are quite as viable as the least old ones (3 years) by recording better capacities of germination. The treatment of these capacities obtained under our experimental conditions, by PCA shows that germination is favoured on the one hand in the presence of daylight, in an interval of temperature of 18 °C at 20 °C, alone or associated to a cold preprocessing of 5 °C during 24 h at 72 h and on the other hand by scarification. Indeed, at daylight, a maximum of germination (90.66% to 94.66%) is reached after a cold preprocessing of 5 °C in particular during 72 h. Scarification results in an improvement of the capacity of germination at the continuous optimal temperature of 20 °C and to the darkness, a better speed of germination, a shorter latency time. These results can be put in connection with the fall of the contents of certain substances known to be inhibiting germination like total phenols, the flavonoïdes, the tannins condensed and hydrolized, after removal of the teguments.

Daylighting Impacts on Human Performance in School

The purpose of this study was to see if we could demonstrate a clear relationship between the presence of daylight and human performance in buildings. In this study we used a statistical technique called multivariate regression analysis, which analyzes the importance and impact of many variables simultaneously. The performance data used were gathered from three school districts. This analysis allowed us to estimate the effect of a wide number of variables and to determine which variables have no significant effect. Using this method, we established a statistically compelling connection between the presence of daylight and student performance. The implications of the results of this study extend beyond the educational sector. We believe the conclusions may be transferable to other types of buildings, such as offices and factories, since it is really human performance we investigated. If daylighting enhances the performance of children in schools, it is not too large a stretch to suppose that it might also enhance the performance of adults in office buildings. Background Up through the 1950s and into the early 60s almost all school buildings in the United States were daylit, i.e., they were intentionally designed to provide sufficient interior daylight for normal daytime visual tasks. However, by the mid-1960s a number of forces came into conflict with the concept of daylit classrooms. Engineers, asked to provide air conditioning in classrooms, argued against the use of large expanses of glass and high ceilings. Educational theorists argued that a more flexible arrangement of open classrooms, grouped in large openplan buildings, would encourage team-teaching and creative learning. Construction economists argued that schools could be built more inexpensively on smaller sites if the classrooms could be grouped together in modules, without constraints on solar orientation. Increasingly, schools were built with little or no daylight provided to the classrooms. In 1974, Belinda Collins of the National Bureau of Standards and Technology (NIST) conducted a major literature review of available research on windows, and concluded there was no conclusive evidence that windows were a necessary component of classrooms. 1 More recently, daylighting has been advocated as a way to reduce lighting energy use in schools and other non-residential buildings. Turning off electric lights when sufficient daylight is available can save a significant amount of lighting energy costs. Because daylight introduces less heat into a building than the equivalent amount of electric light, cooling costs can also be reduced with appropriate daylight design. 2

A novel method for the efficient synthesis of methyl 2-oxo-2-arylacetates and its application to the preparation of fungicidal methyl ( E)- O-methyloximino-2-arylacetates and their ( Z)-stereoisomers

Methyl 2-oxo-2-arylacetates 1, which include some fluorinated compounds, have been synthesized in moderate to excellent yields by reaction of methyl oxalyl chloride with arylzinc halides in the presence of Pd(PPh 3) 4. The highest yields have been obtained when these reactions involved arylzinc bromides which were prepared by conversion of the corresponding aryl bromides to organolithiums, followed by transmetallation with ZnBr 2. Compounds 1 have been converted in high yields to the corresponding ( E)- and ( Z)- O-methyloximino-2-arylacetates (E)- and (Z)- 5 by treatment with O-methylhydroxylamine hydrochloride in pyridine. Compounds (E)- and (Z)- 5 have been easily separated by MPLC on silica gel and their structure and stereochemistry have been assigned by NMR techniques. So prepared compounds of general formula 5 included an agrochemically important fungicide, i.e. (E)- 5 c , its fluorinated structural analogues, as well as compounds which proved to be able to delay the growth of fungal species isolated from deteriorated papers. Interestingly, several compounds of general formula (Z)- 5 underwent partial stereomutation in the presence of daylight and catalytic amounts of iodine.

Reduction of divalent mercury by humic substances — kinetic and quantitative aspects

The combination of a computer controlled titration device with a cold vapour atomic absorption spectrometer was used to examine kinetic and quantitative aspects of the reaction between humic substances and Hg(II). Subsequent injections of Hg(II) into an excess of humic acid produce data about short- and long-term changes in the reductive capacity of humic substances for Hg(II). The use of a second burette for pH-stat titration excludes the effect of pH changes and buffering electrolytes. The pH dependence of the reaction is similar to results with redox titrations: the amount of elemental mercury produced increases with increasing pH. The amount of Hg(II) reduced did not change with different HS concentrations but is correlated linearly to the amount of Hg(II) added. An interference of chloride ions was not observed. The proportion of elemental mercury produced within the first 10 min of the reaction compared to the 60-min interval increases with increasing pH and with the presence of daylight.

New synthetic applications of organotin compounds: synthesis of stereodefined 2-iodo-2-alkenones, 2-substituted (E)-2-alkenones and 2-methyl-2-cycloalkenones

Stereoisomeric mixtures of 3-iodo-3-nonen-2-one, 8a, 2-iodo-1-phenyl-2-octen-1-one, 8b, 2-iodo-1,3-diphenyl-2-propen-1-one, 8c, as well as ( Z)-3-iodo-4-phenyl-3-buten-2-one, 8d, have been efficiently synthesized by a reaction sequence involving a Pd-catalyzed reaction between the corresponding 1-alkynyl ketones, 10, and Bu 3SnH followed by iododestannylation. Stereomutation experiments carried out in the presence of daylight and using catalytic amounts of I 2 showed that the Z stereoisomers of 8a, 8b and 8c, which could be separated by MPLC on silica gel from the corresponding E stereoisomers, as well as compound ( Z)- 8d were more stable than their E stereoisomers. Compounds 8a–d underwent Pd-catalyzed cross-coupling reactions with C 6H 5SnMe 3, CH 2CH-SnBu 3 and SnMe 4 providing an efficient route to the corresponding 2-substituted 2-alkenones, 13. However, the Pd-catalyzed reaction between ( Z)- 8c and PhSnMe 3 afforded a mixture of the expected cross-coupled product, ( E)- 13f with the compound derived from methyl transfer, ( E)- 13e. The couplings involving ( Z)- 8a, ( Z)- 8b, ( Z)- 8c and ( Z)- 8d proceeded with clean retention of stereochemistry, but the Pd-catalyzed reaction between ( E)- 8c and SnMe 4 afforded a stereoisomeric mixture of 13e. On the contrary, the coupling between ( E)/( Z)- 8b and SnMe 4 produced stereoisomerically pure ( E)- 13c. Two 2-iodo-2-cycloalkenones, i.e. compounds 18a and 18b, also reacted with SnMe 4, in the presence of a Pd catalyst, to give the corresponding 2-methyl-2-cycloalkenones, 19a and 19b, respectively, in satisfactory yields. Compound 19b represents a very useful precursor to methylenomycin B, 9.

Second-Level Post-Occupancy Evaluation Analysis

Findings from a detailed analysis of post-occupancy evaluation data, sponsored by LRI, which involved thirteen office buildings typical of current design practice, will be discussed. Analysis of the data indicates that occupant satisfaction can be related to type of lighting system, presence of daylight, and patterns of luminance in the office. 15 refs., 9 figs., 3 tabs.