Internal Illumination Research Articles

Efficiency Analysis of a Passive Daylighting System Based on Northern Malaysia’s Climate

Daylighting design strategy is important in order to have adequate lighting source in a room and necessary to decrease energy consumption for artificial lighting. Passive daylighting system utilizes daylight by collecting, reflecting and diffusing the natural light throughout a given area. The purpose for this study is to monitor, compare and analyse an optimum light pipe system design that can scatter daylight into a room based on three case studies. Lighting analysis was conducted using Autodesk 3ds Max Design software throughout the project based on the actual geographical parameters of Universiti Malaysia Perlis, Malaysia and also using the real sun azimuth on working hours. The results were compared according to the respective designs in order to observe the maximum internal illuminance and the average internal illuminance. The results show that the straight geometry with low aspect ratio produces the highest interior light intensity among other light pipe systems and the average internal illuminance values in the room was able to reach the minimum requirement of a small room which is 200 – 500 lux.

SlicerPIT: software development and implementation for planning and image-guided therapy in photoimmunotherapy.

Photoimmunotherapy is a treatment modality that induces targeted cell death by binding a molecular-targeted drug activated by infrared light to the tumor cells and subsequently illuminating the lesion with infrared light. For deep lesions, a needle catheter is used to puncture the tumor, and an illumination fiber (cylindrical diffuser) is inserted into the catheter lumen for internal illumination. However, it can be challenging to place the cylindrical diffusers in an appropriate position as the deep lesions cannot be often confirmed accurately during surgery. We have developed "SlicerPIT", a planning simulation software for photoimmunotherapy. SlicerPIT allows users to place the cylindrical diffuser with its illumination range on preoperative images in 2D and 3D and export the planning data to external image-guided surgical navigation systems. We performed seven cycles of photoimmunotherapy with SlicerPIT in three patients with recurrent head and neck cancer. Preoperative planning for photoimmunotherapy was conducted using SlicerPIT, which could be imported into the navigation system. During the operation, we punctured the needle catheters along with the treatment plan on the navigation screen. Subsequently, intraoperative CT imaging was performed and overlaid with the preoperative treatment plan to confirm the alignment of the cylindrical diffusers as planned, followed by infrared light illumination. Postoperative imaging showed necrosis and shrinkage of the entire tumor in all cycles. SlicerPIT allows for detailed preoperative treatment planning and accurate puncture. It may be a valuable tool to improve the accuracy of photoimmunotherapy for deep lesions and improve patient outcomes.

Daylight performance of the Modified Double Light Pipe (MDLP) through yearly experimental tests on a scale model of the system

This work focuses on the Modified Double Light Pipe (MDLP), a daylighting system designed to improve the performance of the Double Light Pipe (DLP).The paper shows the results of a yearly experimental activity carried out on a 1:2 scale model of the device. The dynamic metrics DA, cDA, and U0 have been calculated on a seasonal and yearly basis, and the internal illuminance trend has been determined in four representative days: winter and summer solstices, and spring and autumn equinoxes.The system is effective in delivering daylight in underground areas of buildings both on sunny and cloudy days. Particularly, under overcast sky, a good congruence between internal and external illuminances happens, and linear regression equations allow us to determine the internal illuminance as a function of the external one. Under clear sky with sun, this correlation is less precise at the corners of the room, due to the presence of direct solar radiation, while remaining accurate in the central area. The daylight autonomy is significant for target values of 50 and 100 lx, particularly in spring and summer. DA100 ranges between 0.58 and 0.83 in spring and between 0.66 and 0.83 in summer. The uniformity of daylight distribution on the horizontal work plane can be considered acceptable quite in all climatic conditions, particularly in spring and summer with U0 higher than 0.7 in 81 % (spring) and 85 % (summer) of cases. Altogether, the results can be considered satisfactory.

Handheld interventional ultrasound/photoacoustic puncture needle navigation based on deep learning segmentation.

Interventional ultrasound (US) has challenges in accurate localization of the puncture needle due to intrinsic acoustic interferences, which lead to blurred, indistinct, and even invisible needles in handheld linear array transducer-based US navigation, especially the incorrect needle tip positioning. Photoacoustic (PA) imaging can provide complementary image contrast, without additional data acquisition. Herein, we proposed an internal illumination to solely light up the needle tip in PA imaging. Then deep-learning-based feature segmentation alleviates acoustic interferences, enhancing the needle shaft-tip visibility. Further, needle shaft-tip compensation aligned the needle shaft in US image and the needle tip in the PA image. The experiments on phantom, ex vivo chicken breast, preclinical radiofrequency ablation and in vivo biopsy of sentinel lymph nodes were piloted. The target registration error can reach the submillimeter level, achieving precise puncture needle tracking ability with in-plane US/PA navigation.

TactiGraph: An Asynchronous Graph Neural Network for Contact Angle Prediction Using Neuromorphic Vision-Based Tactile Sensing.

Vision-based tactile sensors (VBTSs) have become the de facto method for giving robots the ability to obtain tactile feedback from their environment. Unlike other solutions to tactile sensing, VBTSs offer high spatial resolution feedback without compromising on instrumentation costs or incurring additional maintenance expenses. However, conventional cameras used in VBTS have a fixed update rate and output redundant data, leading to computational overhead.In this work, we present a neuromorphic vision-based tactile sensor (N-VBTS) that employs observations from an event-based camera for contact angle prediction. In particular, we design and develop a novel graph neural network, dubbed TactiGraph, that asynchronously operates on graphs constructed from raw N-VBTS streams exploiting their spatiotemporal correlations to perform predictions. Although conventional VBTSs use an internal illumination source, TactiGraph is reported to perform efficiently in both scenarios (with and without an internal illumination source) thus further reducing instrumentation costs. Rigorous experimental results revealed that TactiGraph achieved a mean absolute error of 0.62∘ in predicting the contact angle and was faster and more efficient than both conventional VBTS and other N-VBTS, with lower instrumentation costs. Specifically, N-VBTS requires only 5.5% of the computing time needed by VBTS when both are tested on the same scenario.

A biodegradable, flexible photonic patch for in vivo phototherapy

Diagnostic and therapeutic illumination on internal organs and tissues with high controllability and adaptability in terms of spectrum, area, depth, and intensity remains a major challenge. Here, we present a flexible, biodegradable photonic device called iCarP with a micrometer scale air gap between a refractive polyester patch and the embedded removable tapered optical fiber. ICarP combines the advantages of light diffraction by the tapered optical fiber, dual refractions in the air gap, and reflection inside the patch to obtain a bulb-like illumination, guiding light towards target tissue. We show that iCarP achieves large area, high intensity, wide spectrum, continuous or pulsatile, deeply penetrating illumination without puncturing the target tissues and demonstrate that it supports phototherapies with different photosensitizers. We find that the photonic device is compatible with thoracoscopy-based minimally invasive implantation onto beating hearts. These initial results show that iCarP could be a safe, precise and widely applicable device suitable for internal organs and tissue illumination and associated diagnosis and therapy.

Visible to Mid-IR Spectromicroscopy with Top-Down Illumination and Nanoscale (≈10 nm) Resolution.

Photothermal induced resonance (PTIR), an atomic force microscopy (AFM) analogue of IR spectroscopy also known as AFM-IR, is capable of nanoscale lateral resolution and finds broad applications in biology and materials science. Here, the spectral range of a top-illumination PTIR setup operating in contact-mode is expanded for the first time to the visible and near-IR spectral ranges. The result is a tool that yields absorption spectra and maps of electronic and vibrational features with spatial resolution down to ≈10 nm. In addition to the improved resolution, the setup enables light-polarization-dependent PTIR experiments in the visible and near-IR ranges for the first time. While previous PTIR implementations in the visible used total internal reflection illumination requiring challenging sample preparations on an optically transparent prism, the top illumination used here greatly simplifies sample preparation and will foster a broad application of this method.

The effect of daylight exposure on the immune response and body condition of Great Tit nestlings

Natural light plays an important role in many aspects of birds’ biology, ecology and behaviour. Wild birds experience various light conditions, both in terms of its intensity and spectral properties, which vary within the nesting habitat of avian species. Recent study has shown that some bird species prefer to build their nests in bright nest sites. Light is one of the major factors affecting early development and condition of nestlings, but to date, this effect has not been tested in wild conditions. This study aims to answer whether birds could benefit from nesting in brighter light environment. Potential benefits may occur in nestlings’ condition, growth rate and breeding output. The research was carried out in the population of Great Tits (Parus major) breeding in two types nest boxes which differed with internal illumination. In “dark” boxes, the only source of light was the entrance hole. “Bright” boxes have additional side semi-transparent windows. We conducted two experiments in which light environment in nest box was set after (Experiment I) or before (Experiment II) birds settle in. Our study showed that light environment did not significantly affect nestlings body condition and growth. However, females in their first breeding attempt showed strong preference to the brightened nest boxes. In this group, the offspring were heavier and showed stronger immune responses than nestlings reared in dark nest boxes. Nestlings in bright nest boxes fledged about one day earlier. Nesting in brightened nest boxes may provide potential benefit for adult females in their first breeding attempt. The interaction between maternal effect and light environment is being discussed.

Daylight Performance of the Modified Double Light Pipe (MDLP) Through Experimental Analysis on a Reduced Scale Model

This paper is focused on the Modified Double Light Pipe (MDLP), an innovative daylighting system set up by the authors in the Laboratory of Technical Physics of the University “G. D’Annunzio” of Pescara (Italy). It is an evolution of the Double Light Pipe (DLP), designed by the authors to distribute natural light in two underground levels of a building and tested through an experimental activity on a reduced scale model. The MDLP has been designed by modifying the same scale model of the DLP with the goal to solve some problems related to its size and the risk of glare, thanks to its smaller encumbrance, and a light shelf applied around the external tube to prevent the occupants of the room from seeing the upper brightest portion of the device. Furthermore, the light shelf reflects light towards the ceiling spreading it more uniformly on the horizontal work-plan. The technological components of the MDLP are shown demonstrating the possibility of installing it in both new and refurbished buildings. Then, the first results of an experimental activity carried out on the model of the MDLP in winter climatic conditions are shown. Although the unfavorable values of external illuminance, the MDLP contributes to distributing natural light in the passage room both with overcast and clear sky conditions. On sunny days, direct solar radiation hits the measure positions on the corners of the room producing peak illuminance values. The illuminance uniformity is calculated according to the EN 12464-1. The results can be considered satisfactory both in terms of internal illuminance and uniformity of light distribution.

Towards the Configuration of a Photoelectrocatalytic Reactor: Part 2-Selecting Photoreactor Flow Configuration and Operating Variables by a Numerical Approach.

This work aims to select a photoreactor flow configuration and operational conditions that maximize the Photocatalytic Space-time Yield in a photoelectrocatalytic reactor to degrade Reactive Red 239 textile dye. A numerical study by Computational Fluid Dynamics (CFD) was carried out to model the phenomena of momentum and species transport and surface reaction kinetics. The photoreactor flow configuration was selected between axial (AF) and tangential (TF) inlet and outlet flow, and it was found that the TF configuration generated a higher Space-time Yield () than the AF geometry in both laminar and turbulent regimes due to the formation of a helical movement of the fluid, which generates velocity in the circumferential and axial directions. In contrast, the AF geometry generates a purely axial flow. In addition, to maximize the Photocatalytic Space-time Yield (), it is necessary to use solar radiation as an external radiation source when the flow is turbulent. In conclusion, the can be maximized up to a value of 45 g/day-kW at an inlet velocity of 0.2 m/s (inlet Reynolds of 2830), solar radiation for external illumination, and internal illumination by UV-LEDs of 14 W/m2, using a photoreactor based on tangent inlet and outlet flow.

Inductively Powered Sensornode Transmitter Based on the Interconnection of a Colpitts and a Parallel Resonant LC Oscillator

An inductively powered passive transmitter architecture for wireless sensornodes is presented in this paper. The intended applications are inductively powered internally illuminated photoreactors. The application range of photoreactors is wide. They are used, e.g., for microalgae cultivation or for photochemistry, just to name two important fields of use. The inductive powering system used to transmit energy to the wireless internal illumination system is to be additionally used to supply the here presented transmitter. The aim of expanding the named internal illuminated photoreactors with wireless sensors is to obtain a better insight into the processes inside it. This will be achieved by measuring essential parameters such as, e.g., the temperature, pH value, or gas concentrations of the medium inside the reactor, which for algal cultivation would be water. Due to the passive architecture of the transmitter electronics, there is no need for batteries, and therefore, no temporal limitations in their operational cycle are given. The data transmission is also implemented using the inductive layer in the low frequency range. The data transmitting coil and the energy receive coil are implemented as one and the same coil in order to avoid interference and unwanted couplings between them, and in order to save weight and space. Additionally, the transmitter works in a two-step alternating cycle: the energy harvesting step, followed by the data transmission step. The measured values are sent using on-off keying. Therefore, a Colpitts oscillator is switched on and off. The circuit is simulated using SPICE simulations and consequentially implemented as a prototype in order to perform practical analyses and measurements. The feasibility of our transmitter is therefore shown with the performed circuit simulations, and practically, by testing our prototype on an internal illuminated laboratory scaled photoreactor.

Daylight retrofitting for a school in Pune

Daylighting is an optimal illumination of building using natural sunlight . The utilization of daylight can significantly affect building aesthetic , energy efficiency, as well as occupant’s comfort,productivity and health.Another purpose of day lighting is to save energy by reducing artificial lighting. In this study existing daylight pattern in school building is studied. Few retrofitting strategies like introduction of skylight, windows alteration and redesigning of the interior space are suggested to get the benefit of optimal daylight. Evaluation of daylighting after retrofitting is done by using Ecotect simulation .After retrofitting considerable increase in daylight performance is observed. Retrofitting suggested here also provides better ventilation with minimized energy consumption. However it should be noted that though retrofitting improves internal illuminance, surrounding structures limits the solar penetration .

Shining a Light on Wastewater Treatment with Microalgae.

Microalgae can produce biofuels, nutriceuticals, pigments and many other products, but commercialization has been limited by the cost of growing, harvesting and processing algal biomass. Nutrients, chiefly nitrogen and phosphorus, are a key cost for growing microalgae, but these nutrients are present in abundance in municipal wastewater where they pose environmental problems if not removed. This is not a traditional review article; rather, it is a fact-based set of suggestions that will have to be investigated by scientists and engineers. It is suggested that if microalgae were grown as biofilms rather than as planktonic cells, and if internal illumination rather than external illumination were employed, then the use of microalgae may provide useful improvements to the wastewater treatment process. The use of microalgae to remove nutrients from wastewater has been demonstrated, but has not yet been widely implemented due to cost, and because microalgae derived from wastewater treatment has not yet been demonstrated as a commercial source for value-added products. Future facilities are likely to be called Municipal Resource Recovery Facilities as wastewater will increasingly be viewed as a resource for water, biofuels, fertilizer, monitoring public health and value-added products. Advances in photonics will accelerate this transition.

Internal Multiple Removal and Illumination Correction for Seismic Imaging

Marchenko equation-based imaging methods have been proved as an effective way to remove the internal multiples. Conventional Marchenko imaging needs the reflection response at the surface and an estimate of the direct arrival times from the virtual source point to the acquisition surface. It contains the procedure of redatuming and imaging. The redatuming process is valid only for layered media with a moderately curved interface. We rederive the single reflection retrieval by a focusing source method based on the scattering theory and avoid the use of redatuming plane and the upgoing/downgoing decomposition. This scheme reproduces a new data free from internal multiples for complex structures, such as salt dome. Our theory/method expands the application range of Marchenko imaging and internal multiple elimination. With an artifact-free image obtained by this procedure, an illumination compensation can be further applied to obtain a high-fidelity image, especially in the subsalt area. Numerical examples using the 2-D SEG/EAGE salt model are shown to validate this method.

Photochemistry at Scale: Wireless Light Emitters Drive Sustainability in Process Research & Development

AbstractCarbon−carbon bond formation by dual Iridium‐Nickel photoredox catalysis has gained a lot of attention for late‐stage cross‐couplings of alkyls with aryls. However, the scalability of such reactions is greatly impeded by the poor light penetration depth into the strongly absorbing reaction media. Wireless internal illumination is a novel technique which circumvents the light penetration issue efficiently and therefore allows to scale photon‐driven reactions by conventional methods. Here we demonstrate that industrially relevant photoredox C−C couplings can be scaled seamlessly to different volumes, achieving qualitatively and quantitatively the same results at all scales. The use of conventional reactor types allows stirred, bubble column or fixed‐bed operation mode and is fully compatible with heterogeneous reaction mixtures. By minimizing reflection losses, we could also show a significant advantage in the reaction rate over an externally illuminated setup at the same light intensity.

Maximizing fucoxanthin production in Odontella aurita by optimizing the ratio of red and blue light-emitting diodes in an auto-controlled internally illuminated photobioreactor

Fucoxanthin has multiple beneficial effects on human health. However, an efficient cultivation strategy for hyper-production of microalgae-based fucoxanthin has been seldom achieved. Here, an auto-controlled photobioreactor (PBR) installed internal light-emitting diodes illumination with adjustable spectra ratio was firstly used to culture Odontella aurita. The results showed that red light (RL) was more suitable for cell growth and fucoxanthin accumulation than blue light (BL) and white light. The biomass and fucoxanthin production were further promoted by optimizing the ratios of RL and BL, with 8:2 giving the highest productivities of 570 and 9.41 mg L-1 d-1, respectively, which is the highest fucoxanthin productivity ever reported under photoautotrophic cultivation. Pilot-scale cultivation demonstrated its promising feasibility in commercial fucoxanthin production. Our study represents a pioneering work of harnessing the PBR with internal illumination for hyper-production of microalgae-based fucoxanthin, and provides feasible strategies for high-efficient production of other value-added products in related species/strains.

Debottlenecking Thermophilic Cyanobacteria Cultivation and Harvesting through the Application of Inner-Light Photobioreactor and Chitosan.

Thermophilic cyanobacteria are a low-carbon environmental resource with high potential thanks to their innate temperature tolerance and thermostable pigment, phycocyanin, which enhances light utilisation efficiency and generates a high-value product. However, large-scale cultivation and harvesting have always been bottlenecks in unicellular cyanobacteria cultivation due to their micrometric size. In this study, a 40-litre inner-light photobioreactor (PBR) was designed for scaled-up cultivation of Thermosynechococcus elongatus E542. By analysing light transmission and attenuation in the PBR and describing it via mathematical models, the supply of light energy to the reactor was optimised. It was found that the hyperbolic model describes the light attenuation characteristics of the cyanobacterial culture more accurately than the Lambert–Beer model. The internal illumination mode was applied for strain cultivation and showed a two-fold better growth rate and four-fold higher biomass concentration than the same strain grown in an externally illuminated photobioreactor. Finally, the downstream harvesting process was explored. A mixture of chitosan solutions was used as a flocculant to facilitate biomass collection. The effect of the following parameters on biomass harvesting was analysed: solution concentration, flocculation time and flocculant concentration. The analysis revealed that a 4 mg L−1 chitosan solution is optimal for harvesting the strain. The proposed solutions can improve large-scale cyanobacterial biomass cultivation and processing.

Internal Illumination to Overcome the Cell Density Limitation in the Scale-up of Whole-Cell Photobiocatalysis.

Cyanobacteria have the capacity to use photosynthesis to fuel their metabolism, which makes them highly promising production systems for the sustainable production of chemicals. Yet, their dependency on visible light limits the cell‐density, which is a challenge for the scale‐up. Here, it was shown with the example of a light‐dependent biotransformation that internal illumination in a bubble column reactor equipped with wireless light emitters (WLEs) could overcome this limitation. Cells of the cyanobacterium Synechocystis sp. PCC 6803 expressing the gene of the ene‐reductase YqjM were used for the reduction of 2‐methylmaleimide to (R)‐2‐methylsuccinimide with high optical purity (>99 % ee). Compared to external source of light, illumination by floating wireless light emitters allowed a more than two‐fold rate increase. Under optimized conditions, product formation rates up to 3.7 mm h−1 and specific activities of up to 65.5 U gDCW −1 were obtained, allowing the reduction of 40 mm 2‐methylmaleimide with 650 mg isolated enantiopure product (73 % yield). The results demonstrate the principle of internal illumination as a means to overcome the intrinsic cell density limitation of cyanobacterial biotransformations, obtaining high reaction rates in a scalable photobioreactor.

Study of load-bearing timber-wall elements using experimental testing and mathematical modelling

Combining timber and glass in the wall elements of the building envelope with the proper orientation of such transparent façade elements enables the utilization of solar energy for heating and internal illumination of the building. However, the asymmetrical layout of timber-glass wall elements in such buildings can result in problems with the horizontal stability of the structure, so their participation to load-bearing capacity of the structure is usually neglected. The study deals with solutions for such elements as horizontal load-bearing members with proper connection details. First, specifically developed timber-glass wall elements were experimentally tested under monotonic and cyclic horizontal point load, and further in combination with classical timber-framed wall elements implemented into special single and two-storey box-house models, which were further experimentally tested on the shaking table. In the second part as the main goal of the study, a quite simple mathematical model of the box-house prototypes is developed using a fictive diagonal element for simulating the racking stiffness of the bracing timber-glass wall element. The calculated results for the 1st vibration period are compared with the previously measured experimental results to prove an accuracy of the developed model. Finally, a linear time-history calculation is done as a sample presentation of the developed mathematical model using Landers acceleration spectrum. The developed mathematical model enables a simple and effective seismic response calculation of timber buildings considering the developed timber-glass wall elements as load-bearing bracing elements against horizontal load actions. The model can also be recommended for using in further parametric numerical academic studies analysing the influence of various parameters.

Overall outdoor experiments on daylighting performance of a self-regulating photovoltaic/daylighting system in different seasons

Compared with the PV electricity generation alone system, the hybrid photovoltaic/daylighting system is more efficient and more economical for the building application. In this paper, a novel self-regulating concentrating photovoltaic/daylighting system is proposed. Because the concentrator is made of the transparent material, the daylighting function can be efficiently incorporated without decreasing its optical efficiency. The transmittance characteristic of the concentrating photovoltaic/daylighting system is a vital parameter that is related to the electrical and daylighting performance of it, which also has a significant impact on the building’s energy consumption behavior. To address this issue, the experimental investigation of this new system towards the visible light transmittance in different seasons and under different weather conditions is presented for the first time. The transmittance evaluation method based on the integrating box is adopted for the experimental test. The experiments are conducted on four different days that are corresponding to different seasons and different weather conditions. The conversion factor of the integrating box is first experimentally calibrated. The internal illuminance on four walls of the integrating box and the external illuminance are obtained, based on results of which, the transmittance of the concentrating photovoltaic/daylighting system is determined. It's found through experimental results that under the sunny weather condition in the summer, autumn, and winter seasons, the daily average tested transmittance of the concentrating photovoltaic/daylighting system is 8.57%, 6.78%, and 7.43% respectively. The experimental results under the overcast weather condition indicate that the transmittance of the concentrating photovoltaic/daylighting system for the diffuse solar irradiance is 7.22%.