Internal Illumination Research Articles

3D Printed Asymmetric Nanoprobe for Plasmonic Nanofocusing under Internal Illumination

Plasmonic nanofocusing (PLNF) is an effective way to squeeze light energy into a region below the diffraction limit and realize highly localized intensity by plasmonic structure, which lays the bas...

Performance evaluation of a top lighting light-pipe in buildings and estimating energy saving potential

Nowadays, an escalation in the development of day-lighting systems is observed as people are fascinated towards day-lighting incorporation so as to get benefitted of the lighting energy savings, along with other intangible benefits like health, well-being, and productivity of the occupants. Light-pipe is one such day-lighting system that enables the natural light to enter the spaces which are located far away from the periphery area of a building and thus, cannot be illuminated by windows or other daylighting devices. Light-pipe, while illuminating the interior spaces, also blocks UV rays, which contributes to the heat gain of a room. The study focuses on the design, optimization, simulation and experimental evaluation of the modification in the conventional light-pipe design towards achieving more light through the pipe. This includes modeling of several structural design modifications in light-pipe and their corresponding ray-tracing simulations in TracePro. Out of these modifications over the conventional straight pipe, the design with the best results has been selected and developed so as to experimentally validate the simulation results. The simulation as well as experimental evaluation of the modified light-pipe in comparison to the conventional light-pipe in terms of the average internal illuminance of the room and the light transmission efficiency of the light-pipe indicates an improvement with the modified design of light-pipe.

Assessment of building façade performance in-terms of daylighting and associated energy consumption in architectural spaces

This paper examines the effect of vertical and horizontal shading devices on the quality of daylight in buildings and the associated energy saving. Excessive daylight in architectural spaces contributes negatively to the energy consumption in buildings. Blinds and shading devices are good solutions to attenuate the surplus amount of daylight in spaces. Accordingly, this study evaluates the effect of shading devices on the amount of light flux and the associated solar energy in buildings. It estimates the energy consumption attributed to lighting spaces for three common positions of shading devices. Computer simulation strategy was undertaken to correlate the illuminance level in spaces with room geometry and architectural shading elements. The Holophane model for lighting calculations was used to estimate the average illuminance level on workplane and correlate it with the expected saving energy in buildings. The study concluded that there is an optimal orientation for shading devices that keeps the internal illuminance level within the acceptable range with minimum amount of solar heat gain.Keywords: Shading device, Daylight Illuminance, Heat gain, Computer simulation, Energy consumption

Lighting Control Including Daylight and Energy Efficiency Improvements Analysis

Energy used for lighting is one of the major components of total energy consumption in buildings. Nowadays, buildings have a great potential to reduce their energy consumption, but to achieve this purpose additional efforts are indispensable. In this study, the need for energy savings evaluation before the implementation of lighting control algorithms for a specified building is highlighted. Therefore, experimental tests have been carried out in a university building with laboratories and other rooms, equipped with KNX building automation system. A dimmable control strategy has been investigated, dependent on daylight illuminance. Moreover, a relationship between external and internal daylight illuminance levels has been evaluated as well. Based on the experimental results, the authors proposed a method for the rough estimation of electrical energy savings. Since, according to the EN 15232 standard, Building Automation and Control Systems (BACS) play an important role in buildings’ energy efficiency improvements, the BACS efficiency factors from this standard have been used to verify the experimental results presented in the paper. The potential to reduce energy consumption from lighting in non-residential buildings by 28% for offices and 24% for educational buildings has been confirmed, but its dependence on specific building parameters has been discussed as well.

Performance Prediction and Assessment of Energy Conservation Potential for a Light Pipe System in Indian Composite Climate of New Delhi

Light pipes are popularly used for transporting outdoor sunlight into deep spaces of the building, and hence, use of artificial lighting could be substantially reduced. Performance prediction of a light pipe is an essential step before its use in buildings, so that energy saving potential of the light pipe could be quantified. This paper deals with experimental validation of three existing semi-empirical models for light pipes with different aspect ratios, installed on a windowless test room, at IIT Delhi, New Delhi. Two new semi-empirical models based on the existing correlations are developed. The new model found to perform better with mean bias error (MBE) and root-mean-squared error (MSE) of 0.076 and 0.01, respectively. The better performing new model is used for the evaluation of hourly internal illuminance by the light pipe in a typical meteorological year (TMY) in New Delhi. From hourly internal illuminance in a typical meteorological year, the energy saving potential and CO2 mitigation potential of light pipe system for the test room are evaluated. Monthly average energy saving potentials of the light pipe-fluorescent tube light system are found to be 50% for continuous dimming control and 38% for three-step on–off control. Results show that the light pipe-fluorescent tube light system, with different lighting controls, could reduce CO2 emissions to 15–50%.

Catching Daylight: Improving Natural Illumination Levels in Deep-Plan Drawing Studios at the University of Jordan

This paper investigates enhancing internal natural illumination levels of existing drawing studios in the Architecture Engineering Department at the University of Jordan for the purposes of securing a better learning environment and lowering energy costs. These studios are artificially lit all daytime despite the existence of large side windows. By using the daylight factor method, the daylight factor was measured inside a selected studio and then via a scale model in the Artificial Sky Lab under clear sky conditions. The scale model enabled us to study several elements or factors affecting daylighting. By using high transmittance glass, changing the windows' wide frames, adding reflective panels facing the studied studio's windows and using bright white paint for the studio's interior walls, the daylight factor increased by 6-13.5% in the studio model. These interventions can be applied on existing and other studios and labs in the University. Moreover, the method used can be replicated to improve daylighting in similar deep-plan rooms due to its easily applicable and simple low-cost tools.

A Vision of Daylight Technologies for High-Rise Residential Building in Tropic

Sidelighting is still the primary lighting opening for most buildings in all part of the world. The technology allows only limited penetration of daylight that causes a high energy consumption for artificial lighting. Using a right daylight technology in high-rise residential building could saving more energy and have a good impact on productivity and occupant’s health. This paper discusses the daylighting technologies for high-rise residential buildings in tropical area with literature review method. Some factors such function of systems, location, ability to change and transparency/the view outside will be the factors that must consider in selecting daylight technologies for high-rise residential building in tropic. The diffuse light-guiding system is a practical daylight technologies for deep floor plan building in tropics. The studies shows that potential daylight technology is diffuse light-guiding system that composed from light shelf, fish sytem and anidolic system. The performance of light shelf influenced by direct sunlight. Its increasing iluminance near window area and causes uneven distribution of illumination in the room. Fish system shows better performance than ordinary blinds, however the result is from integration of fish system and external blinds at low internal illuminance. Application anidolic system in tropical area improving illuminance ratio by factor 3.3, reducing glare by 14%, under overcast sky could transfer daylight upto12.5 m and under intermediate sky up to 20 m. For future work, anidolic system expected to respond sky conditions and direct sunlight for improvement in tropical area.

Widefield and total internal reflection fluorescent structured illumination microscopy with scanning galvo mirrors.

We present an alternative approach to realize structured illumination microscopy (SIM), which is capable for live cell imaging. The prototype utilizes two sets of scanning galvo mirrors, a polarization converter and a piezo-platform to generate a fast shifted, s-polarization interfered and periodic variable illumination patterns. By changing the angle of the scanning galvanometer, we can change the position of the spots at the pupil plane of the objective lens arbitrarily, making it easy to switch between widefield and total internal reflection fluorescent-SIM mode and adapting the penetration depth in the sample. Also, a twofold resolution improvement is achieved in our experiments. The prototype offers more flexibility of pattern period and illumination orientation changing than previous systems.

Quantifying Reversible Surface Binding via Surface-Integrated Fluorescence Correlation Spectroscopy.

We present a simple and versatile single-molecule-based method for the accurate determination of binding rates to surfaces or surface bound receptors. To quantify the reversible surface attachment of fluorescently labeled molecules, we have modified previous schemes for fluorescence correlation spectroscopy with total internal reflection illumination (TIR-FCS) and camera-based detection. In contrast to most modern applications of TIR-FCS, we completely disregard spatial information in the lateral direction. Instead, we perform correlation analysis on a spatially integrated signal, effectively converting the illuminated surface area into the measurement volume. In addition to providing a high surface selectivity, our new approach resolves association and dissociation rates in equilibrium over a wide range of time scales. We chose the transient hybridization of fluorescently labeled single-stranded DNA to the complementary handles of surface-immobilized DNA origami structures as a reliable and well-characterized test system. We varied the number of base pairs in the duplex, yielding different binding times in the range of hundreds of milliseconds to tens of seconds, allowing us to quantify the respective surface affinities and binding rates.

Internal-illumination photoacoustic computed tomography.

We report a photoacoustic computed tomography (PACT) system using a customized optical fiber with a cylindrical diffuser to internally illuminate deep targets. The traditional external light illumination in PACT usually limits the penetration depth to a few centimeters from the tissue surface, mainly due to strong optical attenuation along the light propagation path from the outside in. By contrast, internal light illumination, with external ultrasound detection, can potentially detect much deeper targets. Different from previous internal illumination PACT implementations using forward-looking optical fibers, our internal-illumination PACT system uses a customized optical fiber with a 3-cm-long conoid needle diffuser attached to the fiber tip, which can homogeneously illuminate the surrounding space and substantially enlarge the field of view. We characterized the internal illumination distribution and PACT system performance. We performed tissue phantom and in vivo animal studies to further demonstrate the superior imaging depth using internal illumination over external illumination. We imaged a 7.5-cm-deep leaf target embedded in optically scattering medium and the beating heart of a mouse overlaid with 3.7-cm-thick chicken tissue. Our results have collectively demonstrated that the internal light illumination combined with external ultrasound detection might be a useful strategy to improve the penetration depth of PACT in imaging deep organs of large animals and humans.

Optical model of the murine lung to optimize pulmonary illumination.

We describe a Monte Carlo model of the mouse torso to optimize illumination of the mouse lung for fluorescence detection of low levels of pulmonary pathogens, specifically Mycobacterium tuberculosis. After validation of the simulation with an internally illuminated optical phantom, the entire mouse torso was simulated to compare external and internal illumination techniques. Measured optical properties of deflated mouse lungs were scaled to mimic the diffusive properties of inflated lungs in vivo. Using the full-torso model, a 2 × to 3 × improvement in average fluence rate in the lung was seen for dorsal compared with ventral positioning of the mouse with external illumination. The enhancement in average fluence rate in the lung using internal excitation was 40 × to 60 × over external illumination in the dorsal position. Parameters of the internal fiber optic source were manipulated in the model to guide optimization of the physical system and experimental protocol for internal illumination and whole-body detection of fluorescent mycobacteria in a mouse model of infection.

A novel merging Tubular Daylight Device with Solar Water Heater – Experimental study

Abstract Tubular Daylight device (TDD) and solar water heater (SWH) are two power saving solutions that are commonly employed individually in residential and industrial premises. This paper proposed a novel merged power saving system consisting of TDD and SWH in one model, which is the first attempt to integrate these two systems. The idea of merging the TDD with SWH is based on utilizing the existing area around the TDD to implement the SWH around the TDD tube through a serpentine collector. The main purpose for such integration is to enhance solar energy saving, space area saving, and to decrease the fabrication cost. The illumination and thermal performance of the new proposed model were tested and analysed experimentally in different seasons in Cairo - Egypt to assess its performance in practical use. The obtained results indicated that the merged system succeeded in transferring an acceptable illumination rate and increasing the water temperature. The transferred internal illuminance has reached approximately to 6.5 W/m2 that fulfils the required needs of lighting. Additionally, the system increased the water temperature up to 62 °C, with a performance instantaneous efficiency that reached 21.17% which is very satisfactory. Furthermore, the performance of thermosyphon SWH with different serpentine collector coil number of turns has been evaluated. The results proved that, the collector number of turns has significantly affected the SWH performance in a directly proportional relation.

Internal illuminance and shelter shape affect shelter selection by the Japanese eel Anguilla japonica

ABSTRACTThe present study evaluated the effects of internal illuminance and shelter shape on shelter selection by Japanese eels to enable the preservation or construction of suitable shelters for the Japanese eel. Japanese eels were able to distinguish a 1.25-fold difference in illumination inside the shelters, and preferred darker shelters. When the internal illumination of two shelters with the same shape was less than one-tenth of the ambient illumination (about 400 lx), shelter selection by Japanese eels was not affected by internal illuminance, even when there was a 10-fold difference in internal illumination between shelters. The width of the shelter was not important, but Japanese eels preferred a deep shelter with a low ceiling and walls that spread to a ‘dead end’. This has important implications on the creation of suitable shelters for Japanese eels.

Near-Field Plasmonic Probe with Super Resolution and High Throughput and Signal-to-Noise Ratio

Near-field scanning optical microscopy (NSOM) enables observation of light-matter interaction with a spatial resolution far below the diffraction limit without the need for a vacuum environment. However, modern NSOM techniques remain subject to a few fundamental restrictions. For example, concerning the aperture tip (a-tip), the throughput is extremely low, and the lateral resolution is poor; both are limited by the aperture size. Meanwhile, with regard to the scattering tip (s-tip), the signal-to-noise ratio (SNR) appears to be almost zero; consequently, one cannot directly use the measured data. In this work, we present a plasmonic tip (p-tip) developed by tailoring subwavelength annuli so as to couple internal radial illumination to surface plasmon polaritons (SPPs), resulting in an ultrastrong, superfocused spot. Our p-tip supports both a radial symmetric SPP excitation and a Fabry-Pérot resonance, and experimental results indicate an optical resolution of 10 nm, a topographic resolution of 10 nm, a throughput of 3.28%, and an outstanding SNR of up to 18.2 (nearly free of background). The demonstrated p-tip outperforms state-of-the-art NSOM tips and can be readily employed in near-field optics, nanolithography, tip-enhanced Raman spectroscopy, and other applications.

The Performance of Daylight through Various Windows for Residential Buildings


 A good daylighting strategy is necessary in order to decrease energy consumption for artificial lighting. To provide effective internal illumination, the placing of the right openings in the right positions with suitable type of window and glazing is important. This study focused on the various types and materials of the glass and window, in order to identify the quantity and quality of daylight that penetrates into the residential buildings. Based on a series of measurement, it was identified that type of glazing and window gives major significance on the performance of daylight and thermal performance in residential buildings.
 Keywords windows; illumination level; residential building; occupant’s perception.
 eISSN 2514-751X © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.

Size Measurement of Laser-Induced Damage in Large-Aperture Final Optics

In this paper, a hierarchical kernel extreme learning machine (HK-ELM) is proposed to solve the problem that the size of laser-induced damage (LID) cannot be accurately measured under the condition of inhomogeneous total internal reflection illumination. The proposed method overcomes the limitations of the radiometric method, which depends on a single factor to measure the size of damage. After analyzing the light scattering characteristics of LID with the finite-difference time-domain method, we find that we should consider the influences of multiple factors when measuring the size of damage under the condition of uneven illumination. The experimental results show that HK-ELM can achieve ultra-resolution measurements, and the mean relative error of the measured size predicted by HK-ELM is within 5% on the testing samples. Compared with the traditional technology, the method proposed in this paper effectively improves the measurement accuracy.

Quantitative Chemical Analysis at the Nanoscale Using the Photothermal Induced Resonance Technique

Photothermal induced resonance (PTIR), also known as AFM-IR, is a scanning probe technique that provides sample composition information with a lateral resolution down to 20 nm. Interest in PTIR stems from its ability to identify unknown samples at the nanoscale thanks, in first approximation, to the direct comparability of PTIR spectra with far-field infrared databases. The development of rapidly tuning quantum cascade lasers has increased the PTIR throughput considerably, making nanoscale hyperspectral imaging within a reasonable time frame possible. Consequently, a better understanding of PTIR signal generation and of the fine details of PTIR analysis has become of paramount importance for extending complex IR analysis methods developed in the far-field, e.g., for classification and hyperspectral imaging, to nanoscale PTIR spectra. Here we calculate PTIR spectra via thin-film optics, to identify subtle changes (band shifts, deviation from linear approximation, etc.) for common sample parameters in the case of PTIR with total internal reflection illumination. Results show signal intensity linearity and small band shifts as long as the sample is prepared correctly, with band shifts typically smaller than macroscale attenuated total reflection (ATR) spectroscopy. Finally, a generally applicable algorithm to retrieve the pure imaginary component of the refractive index (i.e., the chemically specific information) is provided to overcome the PTIR spectra nonlinearity.

Development of a laparoscopic training model using a smartphone.

to develop a model of training in video-surgery, of low cost and that uses a smartphone as an image-generating source. We developed a 38cm high, 40cm wide, 40cm long hexagonal-shaped training box, with a front opening of 12x8 cm for coupling the smartphone. The internal illumination is made with LED lamps and for the support of the smartphone, we used a selfie stick, fixed in the upper part of the box, that allows control of height, distance, angulation, and the coupling of devices with different formats. We selected 20 undergraduate students without previous training in video-surgery, who performed four exercises in the box, with assessment of the time and amount of errors in the execution of the tasks. Each student completed the training for three consecutive weeks. We collected the data in spreadsheets for later analysis. Nineteen students completed the training program, with significant improvement in the times and in the number of errors. the developed model was feasible and promoted the acquisition of skills in this group of students. In addition, it presents low cost, is portable and uses common equipment, such as smartphones.

Effect of various bending angles on a passive light pipe for eco-daylighting systems

Daylighting systems is one of alternative to reduce a high energy consumption that caused by artificial lighting. However the use of passive light pipes in daylighting systems with various bending angles may affect the efficiency of light transfer from the sunlight to the room. Thus this paper is proposed to study the effect of various bending angles on a light pipe. Three bending angles of light pipe, which are 0°, 30° and 45°, were analyzed through the experimental works. A test bed room was constructed in order to simulate daylighting in a room. The results were then visualized in graphs based on the efficiency by considering the maximum average internal illuminance achieved by each light pipe. From the results, it shows that when the bending angle increases, the average internal illuminance decreases. And the highest average internal illuminance was achieved by 0° light pipe.

Cortical actin contributes to spatial organization of ER-PM junctions.

Endoplasmic reticulum-plasma membrane (ER-PM) junctions mediate crucial activities ranging from Ca2+ signaling to lipid metabolism. Spatial organization of ER-PM junctions may modulate the extent and location of these cellular activities. However, the morphology and distribution of ER-PM junctions are not well characterized. Using photoactivated localization microscopy, we reveal that the contact area of single ER-PM junctions is mainly oblong with the dimensions of ∼120 nm × ∼80 nm in HeLa cells. Using total internal reflection fluorescence microscopy and structure illumination microscopy, we show that cortical actin contributes to spatial distribution and stability of ER-PM junctions. Further functional assays suggest that intact F-actin architecture is required for phosphatidylinositol 4,5-bisphosphate homeostasis mediated by Nir2 at ER-PM junctions. Together, our study provides quantitative information on spatial organization of ER-PM junctions that is in part regulated by F-actin. We envision that functions of ER-PM junctions can be differentially regulated through dynamic actin remodeling during cellular processes.