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This paper discusses the closed-loop control of a bidirectional full bridge DC-DC converter which aids in the four-quadrant operation of an electric vehicle (EV). Several topologies of bidirectional converters have been recently investigated for optimizing vehicle performance. The bidirectional converters with buck and boost modes of operation aid the four-quadrant operation of drives. The proposed bidirectional converter aids buck and boost modes of operation in both forward and reverse directions of the drive. The buck/boost operation in the forward direction is suitable to operate the traction drive in motoring mode. Also, the buck/boost operation in the reverse direction aids the drive to operate in charging mode. The performance analysis of the bi-directional converter-fed EV drive is done using MATLAB/Simulink software. The different modes of operation of the converter which is utilized for the four-quadrant operation of the drive are validated using a 12-60V hardware prototype. DSP TMS2837D controller is used to control the bi-directional converter and the code generation for the controller is done in MATLAB-DSP integrated platform. The hardware results validate theoretical analysis and simulation studies. [ABSTRACT FROM AUTHOR]

This work presents a sensorless brushless DC motor (BLDCM) drive control, optimized for solar photovoltaic (PV)- and battery-fed light electric vehicles (LEVs). A back-electromotive force (EMF) observer integrated with an enhanced quadrature-phase-locked-loop (QPLL) structure is proposed for accurate rotor position estimation, addressing limitations of existing control methods at low speeds and under dynamic conditions. The study replaces the conventional arc-tangent technique with a QPLL-based approach, eliminating low-pass filters to enhance system adaptability and reduce delays. The experimental results demonstrate a significant reduction in commutation error, with a nearly flat value at 0 degrees during steady-state and less than 8 degrees under dynamic conditions. Furthermore, the performance of a modified single-ended primary-inductor converter (SEPIC) for maximum power point tracking (MPPT) in solar-powered LEVs is verified, minimizing current ripple and ensuring smooth motor operation. The system also incorporates a regenerative braking mechanism, extending the vehicle's range by efficiently recovering kinetic energy through the battery with 30.60% efficiency. The improved performance of the proposed method and system over conventional approaches contributes to the advancement of efficient and sustainable solar-powered BLDC motor-based EV technologies. [ABSTRACT FROM AUTHOR]

Everyday light exposure plays a vital role in circadian entrainment, especially during twilight. Electric lighting can supplement daylight anytime, enabling unlimited human activity; hence, many struggle to combine a healthy sleep regime with social constraints. Dusk/dawn simulators have been developed to compensate for the lack of twilight exposure and are typically applied in residential environments, where people usually sleep. Innovations in tuneable lighting control enable home-integrated dusk/dawn simulation, but it is essential to understand their performance and acceptance in real-life situations. A pilot field study was executed in 14 Swedish apartments and tested 3 lighting control scenarios for effects on behaviour, well-being and sleep patterns during the winter. Data were collected using wearable actigraphy, weekly surveys and interviews. The light intervention influenced wake- and bedtimes and contributed to slightly more consistent sleep schedules. Subjective responses emphasised that the dawn simulation assisted in a calm and peaceful wake-up, providing extra time for morning activities. The dusk simulation was a reminder to go to bed, but not all participants appreciated the light quality. Satisfaction and acceptance of the pre-programmed dusk/dawn control system were very high, provided there would be increased control for the residents. [ABSTRACT FROM AUTHOR]

Aberrant light/dark (LD) cycles are prevalent in modern society due to electric light usage, leading to mood disorders from circadian disruption or misalignment. However, research on the physiological and behavioral effects of LD variations on brain neurotransmitters is limited. We investigated the effects of extreme LD cycles on body weight (BW), core body temperature (Tcore), locomotor activity (ACT), emotional behaviors, and monoamine levels (noradrenaline [NA], dopamine [DA], and serotonin [5-HT]) in male Wistar rats that were exposed to 1 month of either long light phase (20 L:4D), long dark phase (4 L:20D), or normal (12 L:12D) LD cycles. The 20 L:4D rats exhibited blunted rhythms, with decreased amplitude and advanced/delayed acrophase in Tcore and ACT, alongside increased BW. The 4 L:20D rats showed circadian misalignment, with increased/decreased amplitude in Tcore or ACT and delayed acrophase in Tcore and ACT, also gaining BW. In the 20 L:4D group, NA and 5-HT levels decreased in the suprachiasmatic nucleus and amygdala, respectively, while the 4 L:20D group had increased DA and 5-HT levels in the caudate putamen and dorsomedial hypothalamus, respectively. Open field and social interaction tests indicated anxiety-like behaviors in both test groups. Overall, each extreme LD cycle affected Tcore, ACT amplitude, acrophase, and monoamine levels differently, inducing anxiogenic responses. [ABSTRACT FROM AUTHOR]

Copyright of South Architecture / Nanfang Jianzhu is the property of South Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the vehicle driving range of a pure electric light commercial vehicle, this paper proposes to reduce the electric power consumption per 100 kilometers by reducing power consumption and increasing coasting energy recovery power. Firstly, for ECO energy-saving mode, the paper proposes the energy-saving control technology based on different vehicle usage scenarios and working conditions, which significantly reduces the energy consumption of the vehicle in the whole scenario. Secondly, in the view of the coasting energy recovery deceleration of commercial vehicles with empty and full load varies greatly, the paper proposes the energy recovery control based on the vehicle mass to achieve the same coasting deceleration under different loads to recover more energy. Then, for the problem that coasting energy recovery is usually designed with low adhesion coefficient road surface, the paper proposes adaptive adjustment of coasting energy recovery based on road adhesion coefficient. Finally, the pure electric light truck is tested on real road. The results show that the ECO mode reduces the electricity consumption per 100 kilometers by 2.9%, and by 2.1% for scenarios of turning on the air conditioning and opening the car door. The energy recovery strategy based on the vehicle' s mass shows a 2.7% reduction in electricity consumption per 100 kilometers. [ABSTRACT FROM AUTHOR]

Designing and predicting self-organized pattern formation in out-of-equilibrium chemical and biochemical reactions holds fundamental significance. External perturbations like light and electric fields exert a crucial influence on reaction-diffusion systems involving ionic species. While the separate impacts of light and electric fields have been extensively studied, comprehending their combined effects on spatiotemporal dynamics is paramount for designing versatile spatial orders. Here, we theoretically investigate the spatiotemporal dynamics of chlorine dioxide-iodine-malonic acid reaction-diffusion system under photo-illumination and circularly polarized electric field (CPEF). By applying CPEF at varying intensities and frequencies, we observe the predominant emergence of oscillating hexagonal spot-like patterns from homogeneous stable steady states. Furthermore, our study unveils a spectrum of intriguing spatiotemporal instabilities, encompassing stripe-like patterns, oscillating dumbbell-shaped patterns, spot-like instabilities with square-based symmetry, and irregular chaotic patterns. However, when we introduce periodic photo-illumination to the hexagonal spot-like instabilities induced by CPEF in homogeneous steady states, we observe periodic size fluctuations. Additionally, the stripe-like instabilities undergo alternating transitions between hexagonal spots and stripes. Notably, within the Turing region, the interplay between these two external influences leads to the emergence of distinct superlattice patterns characterized by hexagonal-and square-based symmetry. These patterns include parallel lines of spots, target-like formations, black-eye patterns, and other captivating structures. Remarkably, the simple perturbation of the system through the application of these two external fields offers a versatile tool for generating a wide range of pattern-forming instabilities, thereby opening up exciting possibilities for future experimental validation. [ABSTRACT FROM AUTHOR]

The electrical conductivity of Na2O substituted zinc borate glasses has been studied in the frequency range of 10 mHz to 1 MHz and in the temperature range from 313 to 573 K. The conduction mechanism has been ascertained using the values of the frequency exponent (s) extracted from the fitting of experimental data of the real part of electric conductivity in light of the Almond–West equation. Depending on the glass composition, the ac conduction in the glasses happened via correlated barrier hopping and non-overlapping small polaron tunneling conduction models. The electric modulus studies support the assertion of composition dependent conduction mechanisms. Furthermore, electronic conduction and ionic conduction have been studied from impedance investigations. Equivalent circuit models were used to fit the Nyquist and Bode plots of each sample at the temperatures under consideration. It has been found that the activation energy values calculated from conductivity, electric modulus, and impedance measurements are more or less the same. [ABSTRACT FROM AUTHOR]

Daylighting in school classrooms is essential to support the health, well-being, and performance of students, while minimizing electric lighting energy. However, excessive exposure to daylight may lead to visual and thermal discomfort, particularly in tropical regions where daylight is abundant all-year long. A popular daylighting design strategy to overcome this problem is implementing the combination of windows with external shading and complex fenestration systems (CFS) in the form of horizontal slats, but its application in school classrooms is seldom discussed in the literature. Therefore, this study aims to optimize the design of CFS with horizontal slats and external shading devices in tropical school buildings with a bilateral opening typology. Computational modeling and simulation are conducted, utilizing the Radiance simulation engine with the 4 PH matrix method. Sensitivity analysis is carried out to understand the impact of window-to-wall ratio (WWR), interslat spacing distance, slat angle, and shading depth on the annual daylight metrics, followed by optimization using the Wallacei optimizer. The first rank optimal design solution is a WWR of 60%, with a slat spacing of 0.2 m and a slat angle of –45° for east and west façades. The optimal shading depths on the east and west façades are 2.0 and 0.6 m, respectively. [ABSTRACT FROM AUTHOR]

When a homogeneous film of finite thickness is optically probed, interference due to multiple reflections modulates in amplitude the electric field of light. For optical processes located only at the interfaces between two media, as is common for Sum-Frequency Generation (SFG), interference also modulates the contrast between signals generated at the entrance and exit planes of the film. We introduce a universal formalism for Fresnel factors, which bear all the information about interference, valid at any point in a three-layer system and for the three beams involved in the SFG process. Their analysis provides general rules for obtaining a high contrast. In particular, we define four configurations leading to the cancellation of the SFG response from the entrance side of the film when its thickness or the angles of incidence are tuned. Cancellation conditions depend on the polarization of light and follow simple analytical rules, leading to a straightforward experimental implementation. Such a selective cancellation makes it possible to independently measure single components of the nonlinear susceptibility, for example, in a ppp experiment and to separate surface from bulk response by combining a few measurements. [ABSTRACT FROM AUTHOR]

The active materials-loaded reconfigurable metasurface is a potential platform for terahertz (THz) communication systems. However, the requirements of the modulation performance and the modulation rate put forward the opposite requirements on the excited conductivity of active materials. In this paper, we proposed a concept for a metal-doped active material switch that can produce an equivalent high excited conductivity while reducing the required threshold of the active material conductivity, thus balancing the conflict between the two mutual requirements. Based on it, we designed a reconfigurable electromagnetically induced transparency (EIT) metasurface driven by a low excited conductivity of vanadium dioxide  VO 2 , which can achieve the amplitude modulation and amplitude coding under the control of light and electric. Simulation results validate the role of the metal-doped  VO 2  switch on the metasurface. This work provides a new scheme to mediate the contradiction between the modulation performance and the modulation rate in the requirement of active material's excited conductivity, which facilitates the development of new terahertz modulators based on reconfigurable metasurfaces. In addition, the concept of a metal-doped active material switch will also provide a solution to the limitations of active material from the design layer. [ABSTRACT FROM AUTHOR]

Electrophotocatalysis (EPC) has evolved as a new scientific discipline around the boundary of highly active fields: electrochemistry and photocatalysis. EPC allows us to combine the energy of light and electric potential to activate previously inaccessible compounds via single‐electron transfer (SET). Herein, we review the most essential applications of EPC to the C−H functionalization of molecules. This work discusses mechanisms that can be encountered when designing such processes and analyzes technical aspects of performing EPC reactions in the laboratory. [ABSTRACT FROM AUTHOR]

In this article, we analyze the traveling wave solutions of the dimensionless time dependent Paraxial equation. In Paraxial approximation the partial differential approximation is responsible for optical wave propagation. The proposed equation is used when light or electric currents pass through optical systems such as lenses, mirrors, and optical fibers. An extended hyperbolic function method is used to construct traveling wave solutions. By using the proposed method in the Paraxial equation, different types of soliton solutions such as dark solitons, bright solitons, periodic solutions and singular soliton solutions are recovered. These solutions are obtained by carefully choosing the values of certain parameters involved in the method and model. Our findings are original and can greatly contribute to understanding the propagation of light waves. Some important requirements for the validity of solutions are also discussed. In addition, line plots and surface diagrams are presented to demonstrate the physical and behavioral significance of our findings for the proposed model. [ABSTRACT FROM AUTHOR]

This paper deals with the selection of optimal layout variants of planetary transmissions designed for operation as Light Electric Vehicle main gearboxes. The required transmission ratio was calculated, and the optimal two-carrier gear train with two connecting and three external shafts selected. A computer program was used for structural synthesis and to determine the required basic parameters of the component gear trains. The ring gear reference diameter was used to rank the layout variants according to size, with the smallest variants also ranked according to the calculated efficiency ratio. Finally, an optimal variant of the planetary gear train for light electric vehicle application is proposed. The procedure proposed in this paper may be expanded to other applications. [ABSTRACT FROM AUTHOR]

The use of drawn tungsten wire marked a breakthrough in electric lighting which led to a significant advancement in human society and technology. Nowadays, thermal light sources using tungsten filaments are being more and more replaced by semiconductor‐based light‐emitting diodes (LEDs). Despite the lower visibility of incandescent lamps in everyday life, new markets and applications for drawn tungsten wires are opening up, which makes this complex material a highly‐studied subject. One of these applications is the use of heavily drawn tungsten wires as high‐performance reinforcement fibers for new composites that can withstand the extreme environment present in a nuclear fusion reactor. The main advantage of tungsten wires for this class of composites is their ductility and high strength. The wires can be used to increase the high‐temperature strength of copper‐based heat sink materials as well as the fracture toughness of bulk tungsten considered for the use of highly loaded reactor wall components. These new applications for tungsten wire have also given new impetus to the study of their fundamental properties. [ABSTRACT FROM AUTHOR]

Featured Application: The multichannel luminaire systems allow a perfect color rendering of art pieces, while preserving them against light photodegradation. The presented lighting system can be applied in architectural heritage and museums. The appropriate preservation and color rendering of paintings and art pieces are a pending subject in architectural heritage, since, in most of the cases, lighting systems are not really focused on the conservation and suitable perception of these heritage resources, due to the limitations of standard LED lamps and lighting configurations. In this context, a multichannel luminaire system is proposed in the case study of the Cathedral of Seville, providing a variable and rich spectral distribution, which allows an excellent color perception linked to the daylight conditions, while the short-wavelength light is minimized in order to reduce photodegradation. Two scenarios are addressed: Museum of the Cathedral and Evangelist Chapel. The multichannel luminaire system is tested by means of subjective surveys and objective procedures (Farnswoth-Munsell and Natural Color System tests). The results show that the proposed spectral distribution of the multichannel system provides a better color discrimination in comparison with typical lighting systems, as well as a better preservation, defining a suitable lighting technology for architectural heritage. The novelty of this study lies in the multi-parameter approach, taking care of color rendering while photodegradation is minimized. [ABSTRACT FROM AUTHOR]

This paper presents the design and optimization of a bidirectional Dual Active Bridge (DAB) converter for electric vehicle battery charging applications, encompassing both heavy and light electric vehicles. The core of this study is a 5.6 kW DAB converter that can seamlessly transition between 3.7 kW and 11.2 kW power outputs to accommodate different vehicle requirements without the need for circuit component changes. This flexibility is achieved through the novel integration of interleaved and parallel operation capabilities, allowing for efficient operation across a broad power range. Key innovations include the design of a high-frequency transformer with dual secondary outputs to facilitate power transfer at high currents up to 30 A, an optimized thermal design, and minimized stress on the circuit board. The use of next-generation power semiconductors and low-loss magnetic circuit elements has resulted in an optimized single-stage bidirectional converter design that showcases enhanced efficiency and competitiveness in the field. Furthermore, the converter's design enables easy reconfiguration to meet the desired power output, vehicle type, and application needs, making it adaptable for future applications such as Vehicle-to-Grid (V2G) systems. The combination of these features—versatility in power output, efficient high-current transfer, innovative use of power semiconductors, and adaptability for future technologies—positions this DAB converter as a significant advancement in electric vehicle charging technology, offering a scalable solution to meet the evolving demands of electric mobility and renewable energy integration. [ABSTRACT FROM AUTHOR]

This study introduces a progressive methodology for examining the travel behaviour of bicyclists and pedestrians under both daylight and electric lighting conditions. By analysing data from naturalistic/undisturbed settings, we aimed to assess the representativeness of participant behaviour in an invited context compared to that of typical road users. This paper expands upon the methodological exploration initiated in the original Video Analysis of Pedestrian Movement (VAPM) study by analysing the microscopic movements of both pedestrians and bicyclists in outdoor environments under both natural and electric lighting conditions. Furthermore, the paper investigates bicyclists’ bi-directional interactions in a naturalistic setting, adding a valuable dimension to the study's comprehensive analysis. Our research introduces an effective approach to data collection through the use of drone technology to obtain microscopic data from video analysis. This method has the potential to enhance travel quality for bicyclists during the hours of twilight and darkness and increase the likelihood of short motor vehicle trips being replaced by active, sustainable forms of transport.

High-order harmonic generation (HHG) in solids opens new frontiers in ultrafast spectroscopy of carrier and field dynamics in condensed matter, picometer resolution structural lattice characterization and designing compact platforms for attosecond pulse sources. Nanoscale structuring of solid surfaces provides a powerful tool for controlling the spatial characteristics and efficiency of the harmonic emission. Here we study HHG in a prototypical phase-change material Ge2Sb2Te5 (GST). In this material the crystal phase can be reversibly changed between a crystalline and amorphous phase by light or electric current mediated methods. We show that optical phase-switching is fully reversible and allows for dynamic control of harmonic emission. This introduces GST as new addition to materials that enable flexible metasurfaces and photonic structures that can be integrated in devices and allow for ultrafast optical control. [ABSTRACT FROM AUTHOR]

Combining chirality with ferromagnetism is challenging in organic materials and may bring potential application for the cross-integration of multiple disciplines. In this work, we achieved the intrinsic coexistence of chirality and spontaneous spin polarization in the diblock copolymers, where left-handed and right-handed circularly polarized lights present tunability on both the circular dichroism and spin polarization. Without electron dependence of transport in chiral copolymer, chirality is still coupled with spin. The phenomenon observed here is not the traditional chirality induced spin selectivity effect. Moreover, the electric field could also effectively tune the chirality dependence of circular dichroism to further affect the magnitude of spin polarization. Thus, a strong relationship between the chirality and spin polarization is formed in chiral copolymers. In addition, because of the different molecular packing for chiral enantiomers, electron–phonon coupling strengths are different to lead to a difference in spin polarization. Overall, the properties of chirality, spontaneous spin polarization, and photon-chirality-spin coupling are developed and studied, which effectively promotes the ability of potential applications of chiral copolymers. [ABSTRACT FROM AUTHOR]

This paper summarizes the results of numerous studies aimed at improving the operating characteristics of electric motors used in light electric vehicles (LEVs). This review focuses on four types of electric motors that can be installed in the drive wheel rims of LEVs. Due to the availability of new magnetic materials and the use of advanced techniques for optimizing the design of electric motors, new motor topologies have emerged. The latest generation motors have been shown to be more efficient, have higher torque density, and generate less torque ripple. This paper indicates and discusses current trends in the topology of electric motors designed for LEV drives. In this context, the effectiveness of the proposed design modifications in terms of selected motor operational characteristics was assessed. The proposed new topologies were compared with commercial solutions, also in terms of the possibility of improving their operational parameters. [ABSTRACT FROM AUTHOR]

This study analyzed the effect of indoor lighting energy reduction using a daylight-concentrating indoor louver system, which is a renewable energy equipment item. Daylight-concentrating indoor louver systems enhance indoor lighting by directing natural light, entering through windows, into the room via louvers. This study demonstrates significant lighting energy savings through the use of LED-linked dimming control, particularly during the transitional season, achieving an 85.65% reduction in power consumption. In contrast, the winter season showed higher cumulative power consumption due to reduced natural light availability, with a three-day average consumption of 1128.22 W compared to 836.60 W in the transitional season, representing a 25.85% increase. The illuminance distribution analysis revealed that, while winter had higher illuminance at 1 m from the window, the transitional season recorded higher values at 3 m and 5 m, indicating more effective natural light penetration. The solar altitude during the transitional season facilitated even light distribution through daylighting louvers. These findings confirm the substantial energy savings and improved illuminance distribution achieved with daylighting louvers and LED dimming control, with notable efficiency during the transitional season. Consequently, daylight-concentrating indoor louvers are confirmed to be effective in reducing indoor electric lighting energy consumption. [ABSTRACT FROM AUTHOR]

Artificial synaptic devices (ASDs) are attracting widespread attention as highly promising components for use in complex neuromorphic systems, playing crucial roles in addressing the challenges posed by the conventional von Neumann architecture. However, the instabilities of ASDs in high‐temperature environments diminish the reliabilities of the device performances, significantly inhibiting their practical application. Herein, a highly reliable 2D MoS2/GaPS4 ASD that maintains its functionality even after exposure to 400 °C is proposed. Moreover, due to the enhanced charge‐trapping effect of the GaPS4 layer, the memory window expands from an initial 42 to 55 V, accompanied by a substantial on/off ratio of 105, low off‐leakage current of 10−11 A, and high number of endurance cycles (103). The device effectively simulates various biological synaptic functions via electric and light stimulation. Notably, the high electric and light paired‐pulse facilitation indices suggest an exceptional synaptic performance. The findings introduce a novel approach to high‐temperature neuromorphic applications via defect engineering. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Non-image forming effects of electric light can be employed to address problems related to individuals' productivity in isolated and confined extreme environments (ICEs). A systematic review and meta-analysis, registered at PROSPERO (Registration ID: CRD 42022326269), were conducted to thoroughly evaluate the efficacy of the daytime artificial light intervention on alertness, cognition, and mood using psychological, cognitive performance, and physiological multimodal measures. Twenty-eight studies were identified after an extensive search scope of major electronic databases including Web of Science, Embase, PubMed, Scopus, and PsycINFO. Results revealed that the use of daytime light interventions significantly improved alertness and cognition, and reduced the alpha wave of electroencephalogram, whereas no significant difference was observed for mood. Subgroup analyses by intervention attribute suggested that light parameters and time characteristics affected the efficacy of diurnal light intervention with varying degrees. Future work investigating the correlation between the two variables is needed to further our understanding of the impact of daytime electric light on human responses. This study and its methodology can be useful for researchers as they establish lighting design guidelines capable of improving human functions in ICEs. [ABSTRACT FROM AUTHOR]

This paper introduces the results of an experiment on lighting perception and reading speed where data collected in a physical space is compared to that collected in representations of that space simulated through a web survey and three VR Head-Mounted Displays (HMDs). The results build on an experiment, where perceptions of electric lighting conditions in a physical space were compared to those of the same space simulated in a single VR HMD (HTC Vive Pro). This study extends the previous scope to compare three VR HMD groups (cardboard VR, Oculus Quest 2, and HTC Vive Pro) to ratings of the same lighting conditions viewed through 2D-perspective or immersive panoramic images displayed in a web survey. Past research has compared perceptions of daylight and electric lighting scenes between physical and VR environments, but there is a lack of research that compares ratings of lighting conditions between VR HMDs and to other conventional image formats. For the VR HMD groups, the results revealed significant differences in reading speed between the physical space and cardboard VR HMD groups. An analysis of our subjective ratings showed all three VR HMDs producing fewer significantly different ratings from the physical space than either of the web groups, but ratings in the panoramic group outperformed the 2D-perspective group. The findings suggest that the type of VR HMD impacts reading speed in virtual lighting scenes and more immersive images produce less error than 2D-perspective images when compared to ratings in a physical space. [ABSTRACT FROM AUTHOR]

The spectral composition of light has been linked to various non-image-forming responses besides visual photoreception. Accordingly, simulation tools must incorporate the spectral composition of light to account for such responses. A simulation tool was developed which uses N -step algorithm and subdivides the (red, green, and blue) RGB bands into multiple channels. This research intends to validate the tool for different lighting scenarios. A physical model was constructed in which the integral irradiance from 380 nm to 780 nm was measured for three scenarios: diffuse daylight, electric light with variable correlated colour temperature and a combination of both. All three scenarios were simulated with 3, 9, 27 and 81 channels. For scenarios with electric light and combination of daylight and electric light, the nine-channel simulation improved the mean absolute percentage error (MAPE) by 13.9% to 33.9% compared to the three-channel simulation. For continuous daylight, there was only a small improvement of 0.4% when increasing from 3 to 27 channels. In comparison to 9 channels, 27 channels slightly improved MAPE in all the scenarios but substantially increased the simulation time. Increasing the number of channels to 81 is likelier to bring a contribution to more complex scenarios than that presented in this study. [ABSTRACT FROM AUTHOR]

The number of desk workers who frequently conduct their jobs at home has increased dramatically during Covid-19. Work-from-home flexibility makes it attractive for workers and companies, resulting in a "Work-Style Reform" after the Covid-19 pandemic. However, the quick conversion of home spaces into workplaces cannot always sufficiently respond to users' visual comfort and daylight performance needs which are primary contributors to occupant well-being and productivity. Therefore, this study adopts a mixed-methodology method that integrates parametric thinking, biomimetic, conceptual design, kinetic strategy and the DIVA approach to develop a real-time parametric-generative circular design for multi-objective adaptability that optimizes visual comfort and electric lighting energy efficiency for multiple occupants simultaneously. Parametric simulations of 1458 different options (five different runs per case: a total of 7290) were conducted to assess how the louvers perform regarding daylight, glare, and electric energy usage. Implementing an interactive kinetic louver greatly improved daylight performance in all orientations while simultaneously avoiding visual discomfort for multiple occupants. Furthermore, the use of this façade modification resulted in a substantial decrease in electrical lighting energy consumption, reducing the values from 14.22 to 0.2 kWh/m²/year, 8.1 to 0.18 kWh/m²/year, and 12.88 to 0.18 kWh/m²/year for South, East, and West orientations, respectively. Integrating users' lighting level preferences and the dynamic transitory sensitive area on the façade considerably reduces electric lighting consumption by around 99% compared to the ASHRAE 90.1 standard's lighting profile. [ABSTRACT FROM AUTHOR]

In electric or hybrid vehicles' propulsion systems, Permanent Magnet-Assisted Synchronous Reluctance Machines represent a viable alternative to Permanent Magnet Synchronous Machines. Based on previous research work, the present paper proposes, designs, and optimizes two ferrite PMaSynRM topologies, analyzed against a reference machine (also PMaSynRM) with improved torque ripple content, based on similar specifications and dimensional constraints. Considering the trend of increasing the DC voltage level in electric and hybrid vehicles, the optimal topology is included in an analysis of the DC voltage level impact on the design and performances of PMSynRM. [ABSTRACT FROM AUTHOR]

Blue light is an important light wavelength in regulating plant flowering. In a controlled environment (CE) plant production systems, blue light can be manipulated easily and even precisely through electric lighting, especially with the advancement of light-emitted diode (LED) technologies. However, the results of previous studies in the literature about blue-light-mediated flowering are inconsistent, which would limit its practical application in CE plant production while implying that an in-depth study of the relevant physiological mechanism is necessary in the future. This review consolidates and analyzes the diverse findings from previous studies on blue light-mediated plant flowering in varying high-value crops from ornamental plants to fruits, vegetables, and specialty crops. By synthesizing the contrasting results, we proposed the possible explanations and even the underlying mechanisms related to blue light intensity and exposure duration, its co-action with other light wavelengths, background environment conditions, and the involved photoreceptors. We have also identified the knowledge gaps based on these studies and outlined future directions for research and potential application in this promising field. This review provides valuable insights into the important and diverse role of blue light in plant flowering and offers a foundation for further investigations to optimize plant flowering through lighting technologies. [ABSTRACT FROM AUTHOR]

Daylight can reduce electric lighting in buildings. This is facilitated by sensors that relay real-time illuminance data to a light controller. When daylight provides greater than required or desired levels of illuminance, control actions enable electric lights to reduce their output and save energy. Occupant behaviours can block desk sensors and this reduces the amount of energy saved. However, no method exists that can be used to continuously monitor sensors to ensure they operate as intended (e.g. remain unblocked). We carried out a study in an open-plan office building in Singapore, consisting of 39 workstations each fitted with desk illuminance sensors independently controlling a dedicated ceiling light. Power over Ethernet was used to collect individual data signals for both illuminance and power from each workstation. Data were collected across a one month period, sampling signals at every 2-minute interval. A linear support vector machine model accurately classified 99% of the data points using our sensor blocking algorithm. From 447,455 data points analysed, 12% of dataset showed that sensors were blocked and this had an estimated energy penalty of 24%. We do not recommend installing illuminance sensors at the desk. Our study highlights the usefulness of Power over Ethernet for closed-loop daylight harvesting. The data collected can be used to monitor the health of the sensors’ performance to help minimise energy use.

An electro-optic modulator offers the function of modulating the propagation of light in a material with an electric field and enables a seamless connection between electronics-based computing and photonics-based communication. The search for materials with large electro-optic coefficients and low optical loss is critical to increase the efficiency and minimize the size of electro-optic devices. We present a semi-empirical method to compute the electro-optic coefficients of ferroelectric materials by combining first-principles density-functional theory calculations with Landau–Devonshire phenomenological modeling. We apply the method to study the electro-optic constants, also called Pockels coefficients, of three paradigmatic ferroelectric oxides: BaTiO3, LiNbO3, and LiTaO3. We present their temperature-, frequency-, and strain-dependent electro-optic tensors calculated using our method. The predicted electro-optic constants agree with the experimental results, where available, and provide benchmarks for experimental verification. [ABSTRACT FROM AUTHOR]

The widespread use of electric lighting has revolutionised society but brought unintended consequences, notably light pollution, impacting ecosystems and human circadian rhythms. Concerns about anthropogenic light at night (ALAN) have prompted innovative solutions, such as spectral tuning of light sources. In Europe, a recent focus involves the enforcement of red light in outdoor settings to minimise ALAN's impact, particularly on bats. This mini review synthesises literature to provide an overview of the advantages and disadvantages of the use of red light outdoors. There is a need for further examination of the potential ecological consequences of red light, considering challenges in lighting design functionality and broader impacts on diverse species. [ABSTRACT FROM AUTHOR]