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An indoor office space should not only provide adequate illuminance on horizontal planes but also cater to the physiological and psychological requirements of the occupants. This paper aims to describe a lighting simulation-based work conducted in Kolkata, India which modeled an indoor office to investigate the effects of variation in room surface reflectance combinations on user perception, mean room surface exitance (MRSE), average horizontal illuminance and overall uniformity of horizontal illuminance.

A fluorescent illumination system–based office space was modeled and retrofitted with tubular LED lamps in DIALux. Simulations were conducted for 16 different room surface reflectance combinations and a five-point Likert scale-type survey questionnaire was formulated to conduct a survey with 32 test subjects to assess the subjective preferability of each resultant light scene.

Simulation results demonstrate that the relationship between average horizontal illuminance and MRSE as well as between average horizontal illuminance and overall uniformity of horizontal illuminance, was statistically significant (p < 0.001). In the conducted survey, the resultant light scene arising out of the reflectance combination of wall:ceiling:floor = 60%:90%:20% was the most well-received one with 187 convinced agreements (“agree” and “strongly agree” responses).

This work found strong linear correlation between average horizontal illuminance and MRSE and between average horizontal illuminance and overall uniformity. A five-point Likert scale-type survey questionnaire with seven questions was formulated and validated with 32 test subjects (Cronbach’s alpha > 0.9295), which showed that the wall:ceiling:floor reflectance combination of 60%:90%:20% was the most favored choice.

Good illumination creates an aesthetic environment that may positively influence patients’ well-being and provide comfort to the hospital staff. This study aims to focus on exploring the energy efficiency of lighting and subjective perception of the lit environment in a hospital ward to assess quality indicators of ambient lighting conditions.

The existing conventional tubular fluorescent lamp–based lighting system in the surveyed patients’ ward was retrofitted with light-emitting diode (LED) luminaires to explore illumination and energy parameters. Thereafter, a software lighting model was created, simulated and analyzed. A Web-based survey with five bipolar adjective pairs in a semantic differential scale was conducted with 48 participants to record and analyze their subjective responses pertaining to the variations in lamp types and surface reflectance combinations.

The findings imply that the LED tubular lamp–based illumination was deemed more adequate compared to other lamp types and the effects of variations in room surface reflectance combinations on the participants’ responses were statistically significant at α = 0.05 level. The simulated horizontal work plane average illuminance level varied from 131 to 171 lx, mean room surface exitance (MRSE) levels remained between 30 and 90 lm/m² and overall uniformity of illuminance remained between 0.5 and 0.7.

In a hospital ward illuminated by LED tubular lamps, variations in room surface reflectance combinations for a constant luminous flux package output from the lamps may affect the subjective perception of users and the correlation between horizontal work plane average illuminance and MRSE is found to be highly linear (coefficient of determination > 0.97).

This paper aims to focus on determining the effects of location of closed offices on the front facade, rear facade and side facade plans and the indoor layout (left and right users’ cabinets) on perceptual evaluations of users of physical environmental factors.

For this purpose, the responses of 54 academic users who use the Gazi University Technology Faculty Taskent Building offices were taken with the help of a survey.

As a result, it was determined that office users on the front and side facades generally perceived more positively the offices’ environmental factors than office users on the back facade. In addition, it was determined that offices with storage cabinets located to the right of users (Type A) were perceived more positively than storage cabinets located to the left of users (Type B). On the other hand, it was determined that users between the ages of 25–45 who used closed offices generally perceived the physical environmental factors of offices more positively than users between the ages of 46 and 65.

Especially the location of the building, the landscaping, the plan of the rooms and the landscape to which they are directed are major design decisions that cannot be controlled by employees. Therefore, it is necessary to know the positive/negative effects that may occur during use before making design decisions.

The recent surge in light emitting diode (LED) lighting retrofitted into schools in the UK is as a result of the UK Government’s 2050 zero carbon pledge. However, the benefits and consequences of LED retrofit projects for staff and enablers and stakeholder knowledge gaps about LED lighting retrofitting have not been fully explored. The aim of this research is to determine the amount of savings in cost, carbon reduction and kilowatt usage and to confirm if repayment from energy and cost savings derived from LED retrofit school projects funded through the SALIX funding option in the UK would be enough to service the loan. Thus, it examines monetary and non-monetary benefits, internal project stakeholder knowledge gaps and the consequences of LED retrofit for the staff and enablers of a large community college in the UK which is funded through the SALIX funding option.

The methodology relied on a hybrid research approach of a case secondary school through the review of literature, analysis of secondary data, focus group and questionnaire survey. The focus group consists of six key project stakeholders. The secondary data was sourced from the Project IGP [Individual Grade Proposal] and the Positive Energy Report from Zenergi, and the closed online questionnaire survey was used to sample 150 teaching staff and school enablers.

The findings show that stakeholders lack project knowledge, trust and expertise/project comprehension. This is in terms of baseline information, LED technology/management, payback modalities, management of risks and ethical issues around environmental impact. The forecasted SALIX savings were not achieved in real-time, partly because it does not take into consideration the increase in energy costs over the payback period. However, the LED retrofit creates efficiencies; drives down energy costs and energy usage; and drives carbon reduction, helping pupils’ learning, improving productivity and performance, and finally leading to a better lighting environment for the school community.

The study will help schools in the UK that intend to access SALIX finance for LED retrofits to understand the challenges and mitigate the risks. It will also help the government to understand the importance of adjusting the payback modalities to the base price when the retrofit was carried out for real-time savings to be made. The research would be useful in ensuring the proactive involvement of all the identified stakeholders in understanding the challenges and what the function entails.

Over the last few years it has been established that there is a need to re‐evaluate the basis of assessment of the sufficiency of daylight, in rights to light cases, where the loss of daylight after obstruction might lead to injunction and/or damages. The purpose of this paper is to further examine whether the methodology used by surveyors, whereby the effect of glazing, window frames and internal reflectance are ignored, is valid and whether theoretical values can be translated into real values obtained through practical experimentation.

Modern methods of assessment of daylighting, for design purposes, calculate a whole room average as a percentage of available daylight from a Commission Internationale de l’Eclairage (CIE) sky whereas Waldram's methodology, in rights to light cases, results in a contour line marking the series of points in a room where the task lighting, from a uniform sky, would be insufficient for normal use. These two methods appear incompatible and the conundrum is that whilst the courts are seeking to determine adequacy of daylighting to a room, the practitioners need to be able to measure the reduction in a way that has real meaning and can be valued.

By comparing theoretical results using the Waldram methodology with those obtained using the Building Research Establishment (BRE) methodology and with physical measurements on site and in an artificial sky dome, it can be demonstrated that results using the Waldram Diagram, or the proposed CIEL Diagram, can be translated into real values of daylighting for a room and that these values are more realistic than those obtained through the BRE methodology.

This research (which is ongoing) will be useful to practitioners and the courts in determining rights to light cases and is a significant contribution to the debate initiated in this journal by Michael Pitts some 12 years ago.

The paper aims to design the optimum formulation of the nano-titanium dioxide (TiO2) hydrophilic coating system using the synthetic polypropylene glycol (PPG), which can create the reflection and absorption property.

TiO2 nanoparticles are used as fillers, and PPG has been blended at the proper ratio of 1PPG: 0.2TiO2. The prepared resin has been applied onto the glass substrate at different numbers of glass immersions during the dip-coating fabrication process. One-time glass immersion is labeled as T1 coating, two-time glass immersion is labeled as T2 coating and three-time glass immersion is labeled as T3 coating. All the prepared coating systems were left dry at ambient temperature.

T3 coating showed the lowest reading of WCA value at 40.50°, due to higher surface energy at 61.73 mN/m. The T3 coating also shows the greatest absorbance property among the prepared coating systems among the prepared coating. In terms of reflectance property, the T2 coating system has great reflectance in UV region and near-infrared region, which is 16.47% and 2.77 and 2.73%, respectively. The T2 coating also has great optical transmission about 75.00% at the visible region.

The development of thermal insulation coating by studying the relationship between convection heat and reflectance at different wavelengths of incident light.

The developed coating shows high potential for glass window application.

The application of the hydrophilic coating on light absorption, reflectance and transmission at different wavelengths.

This study aims to investigate the effect of color temperature on consumption. Color is one of the most powerful elements of sensory marketing. However, how warm and cool colors drive consumer indulgence and interact with other visual cues is minimally understood.

This research conducts six experiments to investigate the effect of eight warm and cool colors and the effect of warm/cool color’s interaction with reflectance on indulgent consumption/use in various retail environments.

Studies 1a and 1b support the contrasting effects of warm vs cool colors on consumers’ indulgent consumption. Studies 2a and 2b establish the serial mediating role of arousal and self-reward focus in the color-indulgence relationship. Study 3a demonstrates the interactive effect of warm (vs cool) colors and glossy (vs matte) reflectance on consumer indulgence, and Study 3b confirms how glossy (vs matte) reflectance moderates the serial mediating effect of arousal and self-reward focus in the color-indulgence relationship.

This research contributes to the growing stream of research on the visual aspect of sensory marketing, especially color, and advances the theoretical knowledge of how color could be used effectively to influence consumer indulgence.

This research provides actionable managerial implications on the effective use of warm and cool colors and glossy and matte reflectance to influence consumer indulgence.

This research advances the theoretical and empirical knowledge of color’s interaction with other visual sensory cues and the underlying psychological processes shaping consumer indulgence.

The aim of this paper is to present advanced experimental–numerical methods for identification of spectral absorption and scattering properties of highly porous ceria ceramics in the range of semi-transparency at room and elevated temperatures.

At room temperature, a period of quasi-steady oscillations of the sample surface temperature generated in response to recurrent laser heating at fixed values of the maximum and minimum temperature of the irradiated surface is measured along with the normal-hemispherical reflectance. Radiative properties are then identified using a combined heat transfer model. At elevated temperatures, an analytical solution proposed in an earlier study for zirconia ceramics is used to retrieve spectral absorption coefficient of ceria ceramics from the measured normal emittance.

This method can be used to obtain small absorption coefficient of ceria ceramics at room temperature. The required measurements of both the normal-hemispherical reflectance and the period of quasi-steady oscillations of the irradiated surface temperature of the ceramics sample between fixed values of the maximum and minimum temperatures can be readily conducted using thermal laboratory equipment. Another method has been suggested for identification of the spectral absorption coefficient of ceria ceramics at elevated temperatures. This method is based on a relation between the measured normal emittance of an isothermal sample and the absorption coefficient.

Lighting in building sectors (consumes the highest energy in commercial buildings and the second highest in residential buildings in India) has very much potential for energy conservation in buildings. With the use of daylighting system, energy consumption in lighting can be lowered up to 30 to 40 per cent.

An experimental effort has been made in this paper to explore the internal wall coloring effect on the performance of tubular light pipe. Trace-pro software has been used and validated. With the help of this software, light pipe has been designed and simulated in a ray tracing mode. Assessment of four globally used prediction models has also been conducted to compare the performances in different seasons for light pipes in the composite climate of New Delhi.

It has been conducted based on three statistical indicators as mean bias error, root mean square error and R². Using regression, an empirical model for average internal illuminance has been developed as a function of light reflectance value (LRV) and solar altitude angle. Trace-pro results confirmed that maximum internal illuminance can be obtained with wall surfaces coated with high LRV color. Finally, by using of a single light pipe system for a test room with the artificial lighting system and applying continuous dimming control, the amount of electrical energy has been saved up to 38.5 per cent per year.

After going through the literature, it has been identified that there has been no paper published which explores the effect of colors of the internal walls on the performance of the light pipe. Along with this, the comparison between existing empirical performance models and find out which model gives the best result in different seasons has been carried out for New Delhi, India.

Photon absorbance and reflectance are the most important parameters for the recombination of electron-hole pairs. Bandgap energy plays a vital role in photon absorption. That is, the photons with energy greater than band gap energy are absorbed. Also, the refractive index of semiconductors is responsible for photon reflection, as the surface with the highest refractive index will reflect more photons than a surface with have a low refractive index. The purpose of this paper is to improvise the absorbance and reduce the reflectance of photons on the front surface of solar cells.

Photon reflection is results in reduction in electron-hole pair generation due to the high refractive index of semiconductive materials. To overcome this problem, an Anti-reflection (AR) coating of TiO₂ and SiO₂ is undertaken on solar cells through the Sol-spin coating method. Finally, the effectiveness of the Anti-Reflection coating is scrutinized through UV Vis-Spectroscopy, which provides details regarding reflectance, absorbance and bandgap energy characteristics.

UV–visible spectroscopy was used to measure the responses from the samples. The samples responded to the ultraviolet and visible range of electromagnetic radiation perfectly. UV spectroscopy was done before and after the antireflection coating of TiO₂ and SiO₂ over the solar cell to find their corresponding extreme reflectance and absorbance values. The effects of TiO₂ and SiO₂ were evaluated from the results.

In this research work, the authors have done anti-reflection coating over solar cells with nanoparticles derived from sol-gel process. Absorbance of photons observed through diffuse reflection method.