Journal articles: 'Micro-reflectance'

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Ullattil, Sudeep, Sudheesh Kakkarath, Vinod Viswambharanunnithan, and Suresh Padiyath Ramannair. "Investigations on the Influence of Surface Textures on Optical Reflectance of Multi-crystalline Silicone (MC-Si) Crystal Surfaces-Simulations and Experiments." International Journal of Renewable Energy Development 11, no. 2 (December 28, 2021): 375–83. http://dx.doi.org/10.14710/ijred.2022.38538.

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MC-Si is the most widely used material for making solar PV cells. In spite of the considerable research on improving the conversion efficiency of MC-Si solar PV cells still it remains well within the range of 15-20%. Optical reflectance being the major loss of incident solar energy, efforts are being made to reduce the optical reflectance of solar cell surfaces. Among the several methods proposed, creation of well-defined surface topography on the cell surface remains a promising option. Micro/nano level features with various dimensions and distributions have been created on MC-Si crystal surfaces using a femto-second pulsed laser and the influence of surface topography on optical reflectance in the incident light wave length of 350 – 1000 nm have been studied and compared with the simulation results obtained using OPAL2 software. Experimental results indicate that surface textures on the wafer surface lead to the reduction of optical reflectance in the range of 20-35% in comparison with plain surface. Width of micro grooves have less significant effect on the optical reflectance in comparison with pitch between the micro grooves. Best reduction in reflectance is exhibited by the texture having a groove width of 30 mm and a pitch of 100 mm. A post texturing etching operation is found to have detrimental effect on the ability of micro/nano level features in decreasing the optical reflectance in the preferred wavelength of solar spectrum due to the flattening of nano level features created within the micro grooves due to laser texturing.

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Feng, Guo Jin, Ping Li, Yu Wang, Cheng Li, and Li Zhao. "Reflectance of Micro-Structural Material on Au." Materials Science Forum 663-665 (November 2010): 154–57. http://dx.doi.org/10.4028/www.scientific.net/msf.663-665.154.

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The high absorption characteristics, the complex mechanism and the great potential application in detectors of micro-structural material aroused extensive attention. In order to understand the impact of the micro-structure, the optical simulation method based on Monte Carlo is used for reflection characteristics of micro-structural material with the cell of pyramid construction. In this simulation, the body material is made of gold, which can avoid the effect of tranmittance, with a number of 400 cells. The bottom square of each structure is 50×50 µm, and the height of cells is adjustable. Then the relationship between the height and reflectance can be built up. However, a very complex relationship between the reflectance and the input parameters, including refractive index, extinction coefficient and the structure of the material is showed from simulation result. Generally, the reflectance decreases while the height increases.

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Kurihara, K., K. Fukui, T. Yanagawa, and A. Yamamoto. "Infrared micro optical reflectance spectra of InN." physica status solidi (c) 5, no. 6 (May 2008): 1759–61. http://dx.doi.org/10.1002/pssc.200778628.

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Shi, Jiarui, Qian Shen, Yue Yao, Fangfang Zhang, Junsheng Li, and Libing Wang. "Field Radiometric Calibration of a Micro-Spectrometer Based on Remote Sensing of Plateau Inland Water Colors." Applied Sciences 13, no. 4 (February 7, 2023): 2117. http://dx.doi.org/10.3390/app13042117.

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Remote sensing reflectance (Rrs), which is currently measured mainly using the above-water approach, is the most crucial parameter in the remote sensing inversion of plateau inland water colors. It is very difficult to measure the Rrs of plateau inland unmanned areas; thus, we provide a measurement solution using a micro-spectrometer. Currently, commercial micro-spectrometers are not factory calibrated for radiation, and thus, a radiometric calibration of the micro-spectrometer is an essential step. This article uses an Ocean Optics micro-spectrometer (STS-VIS) and a traditional water spectrometer (Trios) to simultaneously measure the irradiance and radiance of diffuse reflectance plates with different reflectance values for field calibration. The results show the following: (1) different fiber types have different calibration coefficients, and the integration time is determined according to the diameter of the fiber and the type of fiber, and (2) by comparing the simultaneous measurement results of STS-VIS with Trios, the mean absolute percentage difference (MAPD) of both reached 18.64% and 5.11% for Qinghai Lake and Golmud River, respectively, which are accurate Rrs measurements of water bodies. The Rrs of the Hoh Xil and Qarhan Salt Lake water bodies in unmanned areas of China was measured, and this was the first collection of in situ spectral information with a micro-spectrometer. This article shows that the micro-spectrometer can perform the in situ measurement of water Rrs in unmanned inland areas. With this breakthrough in the radiometric performance of the micro-spectrometer, we are able to obtain more accurate remote sensing reflectance results of unmanned water bodies.

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Chen, Yong, Weiping Peng, Xiaofeng Hu, and Chen Zhang. "Functional Performance of Silicon with Periodic Surface Structures Induced by Femtosecond Pulsed Laser." Coatings 12, no. 6 (May 24, 2022): 716. http://dx.doi.org/10.3390/coatings12060716.

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A micro/nano surface structure can produce specific properties, such as super hydrophilicity, low reflectance property, etc. A femtosecond laser-induced periodic surface structure is an important manufacturing process for the micro/nano structure. This research investigated the effects of scanning intervals and laser power on the surface morphology, wetting properties, and reflectance properties of LIPSS based on a silicon wafer. The results showed that the laser power had a significant effect on the surface morphology and wettability of silicon. With the increase of laser power, the surface roughness, etching depth and surface hydrophilicity increased. However, the laser power had little effect on the surface reflectance. The scanning interval had a great influence on the wettability and reflectance property of silicon. With the decrease of the scanning interval, the surface hydrophobicity and reflectance of silicon first decrease and then remain basically stable from 10 μm.

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Neshchimenko, Vitaly V., Chun Dong Li, Mikhail M. Mikhailov, and Andrei Dudin. "Effect of the Surface Morphology of Zinc Oxide Particles on their Radiation Stability." Defect and Diffusion Forum 386 (September 2018): 338–42. http://dx.doi.org/10.4028/www.scientific.net/ddf.386.338.

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The effect of protons exposure on the diffuse reflectance spectra of the zinc oxide with different shape particles has been investigated. Particles were micro-, nanocrystals, star and flower shape particles. The synthesis of the particles was carried out by the hydrothermal method using zinc acetate chemicals. The surface morphology, surface area and crystal structure of the particles have been investigated. Evaluating the changes in spectral reflectance it was found that the radiation stability of the micro particles is higher than the radiation stability of the other nanostructured particles. The high stability of the micro particles optical properties is due to the effect of low accumulation of radiation-induced defects.

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Zheng, Xiao Dong, Yan Zhong Ye, and Lin Fang Shen. "The Measurements of Spectral Reflectance Spatial Distribution on Mc-Si Solar Cell Surface." Applied Mechanics and Materials 241-244 (December 2012): 2184–87. http://dx.doi.org/10.4028/www.scientific.net/amm.241-244.2184.

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Measurement results of spectral reflectance spatial distribution on multi-crystalline silicon solar cells surface are presented. The optical measurement apparatus employs a specific designed micro-spectral reflectance meter. It is suitable for working in visible wavelength range; measurable sample size can be as small as 0.06mm. Results of reflectance distribution on mc-Si solar cell are presented as a spatial sampling interval of 0.1 mm. The peak values of spectral reflectance appear about 400nm wavelength and vary from 10% to 30% with the spatial position on solar cell.

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Lastras-Martínez, L. F., O. del Pozo-Zamudio, R. Herrera-Jasso, N. A. Ulloa-Castillo, R. E. Balderas-Navarro, J. Ortega-Gallegos, and A. Lastras-Martínez. "Micro reflectance difference techniques: Optical probes for surface exploration." physica status solidi (b) 249, no. 6 (February 21, 2012): 1119–23. http://dx.doi.org/10.1002/pssb.201100738.

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Guo, Ting Liang, Guo Jin Feng, and Ting Ting Guo. "Absorption Simulation of Micro-Structual Material on BK7." Key Engineering Materials 467-469 (February 2011): 873–76. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.873.

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The absorption characteristics of micro-structural material, such as “black silicon”, aroused extensive attention. In order to understand the impact of the micro-structure, based on Monte Carlo method, the optical simulation is used for absorption characteristics of micro-structural material. In this paper, the body material used for simulation is a kind of glass, BK7, which has been widely used. And, there are a number of 400 structual cells in the model. The bottom square of each cell is fixed to 50×50 µm, and the height of cells is adjustable. For each height, the reflectance, transmittance and absorption of microstructural material can be caculated. Then the relationship between the height and reflectance, transmittance and absorption can be built up. In our simulation, a very complex relationship between the absorption and the the structure of the material is showed. Generally, the absorption increases while the height of microstructual cell increasing.

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Ganesh, T., K. Perumal, R. Kumar, and N. Bhaskar. "Effect of Thickness on Micro-Structural and Optical Properties of Al-Doped ZnO Films Prepared by Sol-Gel Spin Coating." Nano Hybrids and Composites 17 (August 2017): 171–78. http://dx.doi.org/10.4028/www.scientific.net/nhc.17.171.

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Aluminium (Al) doped Zinc oxide (ZnO) thin films of different thicknesses were prepared on glass substrates by sol-gel spin coating method. The effect of thicknesses on micro-structural and optical properties was investigated for transparent conducting oxide (TCO) application in solar cells and other optoelectronic applications. Grazing incidence x-ray diffraction (GIXRD) showed maximum orientation along (002) plane of c-axis. The variation of different structural parameters like crystallite size, micro-strain, c-axis strain, dislocation density as a function of film thickness was investigated. The FTIR spectra confirmed the formation of Al-doped ZnO film. FESEM images showed spherical shaped nanosized grains and formation of micro pores. The optical absorption increased and absorption peak shifted towards longer wavelength (red shift) with increase in the thickness of the film respectively. The optical transmittance of all the films has a transparency of more than 75% in the visible region. The optical band gap (Eg) decreased with increase in the film thickness. The diffused reflectance (DRS) showed very low reflectance in the region of 400-800 nm, but increased in the 800-900 nm region. Photoluminescence (PL) spectra of the prepared films showed intense band edge UV and low intense visible emissions respectively. The effect of thickness of Al-doped ZnO film on micro-structure, surface morphology, optical absorption and transmittance, diffused reflectance and PL have been investigated and the results are reported.

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Schwinger, Laura, Sebastian Lehmann, Lukas Zielbauer, Benedikt Scharfe, and Thorsten Gerdes. "Aluminum Coated Micro Glass Spheres to Increase the Infrared Reflectance." Coatings 9, no. 3 (March 12, 2019): 187. http://dx.doi.org/10.3390/coatings9030187.

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The reflective properties of micro glass spheres (MGS) such as Solid Micro Glass Spheres (SMGS, “glass beads”) and Micro Hollow Glass Spheres (MHGS, “glass bubbles”) are utilized in various applications, for example, as retro-reflector for traffic road stripe paints or facade paints. The reflection behavior of the spheres can be further adapted by coating the surfaces of the spheres, e.g., by titanium dioxide or a metallic coating. Such coated spheres can be employed as, e.g., mid infrared (MIR)-reflective additives in wall paints to increase the thermal comfort in rooms. As a result, the demand of heating energy can be reduced. In this paper, the increase of the MIR-reflectance by applying an aluminum coating on MGS is discussed. Aluminum coatings are normally produced via the well-known Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD). In our work, the Liquid Phase Deposition (LPD) method, as a new, non-vacuum method for aluminum coating on spherical spheres, is investigated as an alternative, scalable, and simple coating process. The LPD-coating is characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and reflection measurements. The results are compared to a reference PVD-coating. It is shown that both sphere types, SMGS and MHGS, can be homogeneously coated with metallic aluminum using the LPD method but the surface morphology plays an important role concerning the reflection properties. With the SMGS, a smooth surface morphology and a reflectance increase to a value of 30% can be obtained. Due to a structured surface morphology, a reflection of only 5% could be achieved with the MHGS. However, post-treatments showed that a further increase is possible.

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Folland, Thomas G., Tobias W. W. Maß, Joseph R. Matson, J. Ryan Nolen, Song Liu, Kenji Watanabe, Takashi Taniguchi, James H. Edgar, Thomas Taubner, and Joshua D. Caldwell. "Probing hyperbolic polaritons using infrared attenuated total reflectance micro-spectroscopy." MRS Communications 8, no. 04 (October 1, 2018): 1418–25. http://dx.doi.org/10.1557/mrc.2018.205.

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Hacura, A., R. Wrzalik, and A. Matuszewska. "Application of reflectance micro-infrared spectroscopy in coal structure studies." Analytical and Bioanalytical Chemistry 375, no. 2 (January 2003): 324–26. http://dx.doi.org/10.1007/s00216-002-1645-8.

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Miyazaki, Koji, Masahiro Kihara, Ryosuke Sameshima, and Hiroshi Tsukamoto. "G225 Reflectance of close-packed structures of silica micro-spheres." Proceedings of the Thermal Engineering Conference 2007 (2007): 415–16. http://dx.doi.org/10.1299/jsmeted.2007.415.

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Sun, Jian, Wei Li Zhang, Kui Yi, and Jian Da Shao. "High-Reflectance Coatings at 193nm." Advanced Materials Research 631-632 (January 2013): 110–15. http://dx.doi.org/10.4028/www.scientific.net/amr.631-632.110.

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As an important component in 193nm laser system, high-reflectance (HR) coatings with excellent optical and mechanical properties are needed urgently. In this study, we designed and produced three different HR coatings at 193nm, Al2O3/ AlF3 coating, LaF3/ AlF3 coating and a double stack mirror with combination of Al2O3/ AlF3 and LaF3/ AlF3. With 14 layer pairs, the reflectance of Al2O3/ AlF3 coating could reach 98% which could not get higher duo to the absorption of Al2O3. The reflectance of LaF3/ AlF3 coatings could achieve 98.13% with 15 layer pairs. When the layer pair increased to 16, the reflectance lessened ascribed to steep rise in scattering loss caused by micro-cracks occurred in the coatings. A mirror with combination of Al2O3/ AlF3 and LaF3/ AlF3 could obtain the reflectance of 98.78% as deposited. Even 4 months later the value could still reach 98.47% which was an excellent candidate for practical application.

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Sugiyama, Toyohiko, Hiroshi Kakiuchida, and Masayoshi Ohashi. "Visible and Infra-Red Reflectance of Several Typical Japanese Glazes for Roof Tiles and Wall Tiles." Advances in Science and Technology 68 (October 2010): 96–101. http://dx.doi.org/10.4028/www.scientific.net/ast.68.96.

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. Tile coating with a higher reflectance of sun light are effective in mitigating heat-island phenomenon. Covering the surface of the ground or the exterior of buildings with such high reflectance coatings has attracted attention because of its high cost effectiveness. Recently, companies producing Japanese roofing tiles or wall tiles have been trying to develop high reflectance glaze for their products. However, while we have enormous amounts of data on visible reflectance measured through the study of glaze coloration, there are comparatively less data pertaining to infrared reflectance on pottery glazes. Though optical properties of simple glass and ceramics have been extensively studied, pottery glazes are complex glass-crystalline micro-composites. The pottery glazes sometimes have heterogeneous structures caused by phase separation, crystallization in the base glass, oriented crystallization on the surface, and so on, which are considered to affect infrared reflection. In this paper, several kinds of typical Japanese glazes are characterized from the point of view of the visible and infra-red spectral reflectance, and the improvement of these characteristics is discussed.

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Sen, Bhupendra K., Swapnil Tiwari, Manas Kanti Deb, and Shamsh Pervez. "Nanogram level quantification of molybdenum(vi) by novel hyphenated SDME/DRS-FTIR in human biological fluid." Analytical Methods 7, no. 22 (2015): 9474–81. http://dx.doi.org/10.1039/c5ay01801c.

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A novel hyphenated single-drop micro-extraction (SDME) diffuse-reflectance Fourier-transform infrared spectroscopy (DRS-FTIR) technique was employed for the quantification of hexavalent molybdenum, i.e., Mo(vi) in human blood serum and urine.

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Zhu, Yihua, and Daniel Fried. "Measurement of the Depth of Lesions on Proximal Surfaces with SWIR Multispectral Transillumination and Reflectance Imaging." Diagnostics 12, no. 3 (February 26, 2022): 597. http://dx.doi.org/10.3390/diagnostics12030597.

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The aim of this study was to compare the diagnostic performance of dual short-wavelength infrared (SWIR) transillumination and reflectance multispectral imaging devices for imaging interproximal lesions with radiography using extracted teeth that had been imaged with micro-computed tomography (microCT). Thirty-six extracted teeth with 67 lesions on the proximal surfaces were imaged using a newly fabricated SWIR multispectral proximal transillumination and reflectance imaging device along with an existing SWIR multispectral occlusal transillumination and reflectance device. The ability of SWIR imaging and radiography to detect lesions and accurately assess lesion dimensions were compared using microCT as a standard. Occlusal and proximal transillumination and occlusal reflectance performed best for imaging interproximal lesions while proximal reflectance was not useful for imaging interproximal lesions from tooth buccal and lingual surfaces. There was high correlation of the lesion dimensions measured in occlusal and proximal transillumination images compared to microCT and moderate correlation in occlusal reflectance images. The correlation between the lesion depth measured in radiographs and the lesion depth measured with microCT was not significant. This study demonstrates that SWIR occlusal and proximal transillumination and SWIR occlusal reflectance images are useful for imaging interproximal lesions and they provide more accurate measurements of lesion severity.

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Gong, Chizhang, Henning Buddenbaum, Rebecca Retzlaff, and Thomas Udelhoven. "An Empirical Assessment of Angular Dependency for RedEdge-M in Sloped Terrain Viticulture." Remote Sensing 11, no. 21 (October 31, 2019): 2561. http://dx.doi.org/10.3390/rs11212561.

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For grape canopy pixels captured by an unmanned aerial vehicle (UAV) tilt-mounted RedEdge-M multispectral sensor in a sloped vineyard, an in situ Walthall model can be established with purely image-based methods. This was derived from RedEdge-M directional reflectance and a vineyard 3D surface model generated from the same imagery. The model was used to correct the angular effects in the reflectance images to form normalized difference vegetation index (NDVI) orthomosaics of different view angles. The results showed that the effect could be corrected to a certain scope, but not completely. There are three drawbacks that might restrict a successful angular model construction and correction: (1) the observable micro shadow variation on the canopy enabled by the high resolution; (2) the complexity of vine canopies that causes an inconsistency between reflectance and canopy geometry, including effects such as micro shadows and near-infrared (NIR) additive effects; and (3) the resolution limit of a 3D model to represent the accurate real-world optical geometry. The conclusion is that grape canopies might be too inhomogeneous for the tested method to perform the angular correction in high quality.

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Vermeulen, Marc, Katherine Eremin, Georgina Rayner, Kate Smith, Timothy Cavanaugh, Arthur McClelland, and Marc Walton. "Micro reflectance imaging spectroscopy for pigment identification in painting cross sections." Microscopy and Microanalysis 27, S1 (July 30, 2021): 2806–8. http://dx.doi.org/10.1017/s1431927621009818.

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Grunwald, R., and U. Griebner. "Segmented solid-state laser resonators with graded reflectance micro-mirror analysis." Pure and Applied Optics: Journal of the European Optical Society Part A 3, no. 4 (July 1994): 435–40. http://dx.doi.org/10.1088/0963-9659/3/4/003.

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Harthcock, M. A., L. A. Lentz, B. L. Davis, and K. Krishnan. "Applications of Transmittance and Reflectance Micro/FT-IR to Polymeric Materials." Applied Spectroscopy 40, no. 2 (February 1986): 210–14. http://dx.doi.org/10.1366/0003702864509529.

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Recent advances in FT-IR microsampling techniques have increased the specificity with which infrared spectra of microscopic samples or regions of microscopic samples can be obtained. In this paper, application of microsampling techniques to several problems involving polymeric materials will be presented. The technique using transmittance methods is shown to be a fast method for isolating two particles in a heterogeneous mixture and obtaining infrared spectra to conclusively identify the particles. The infrared absorption spectra of several layers of a multilayer polymer structure ranging in size from 8 to 50 μm are identified with the use of the technique. The surface of an imperfection in a painted polymer (approximately 150 μm diameter) is studied with the use of the infrared reflectance capabilities. These microsampling techniques prove useful and unique for specialized problems involving polymeric materials. The data obtained by the use of these microsampling techniques could not be obtained by “conventional” microsampling methods.

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Shen, Wanfu, Chunguang Hu, Shuai Li, and Xiaotang Hu. "Using high numerical aperture objective lens in micro-reflectance difference spectrometer." Applied Surface Science 421 (November 2017): 535–41. http://dx.doi.org/10.1016/j.apsusc.2016.12.166.

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Schulz, H., and B. Kropp. "Micro spectroscopy FTIR reflectance examination of paint binders on ground chalk." Fresenius' Journal of Analytical Chemistry 346, no. 1-3 (1993): 114–22. http://dx.doi.org/10.1007/bf00321394.

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Liu, Yan, Yu Ning, Wensheng Cai, and Xueguang Shao. "Micro-analysis by near-infrared diffuse reflectance spectroscopy with chemometric methods." Analyst 138, no. 21 (2013): 6617. http://dx.doi.org/10.1039/c3an01232h.

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Habka, Nada, Véronique Soulière, Jean Marie Bluet, Maher Soueidan, Gabriel Ferro, and Yves Monteil. "Optical Investigation of Cubic SiC Layers Grown on Hexagonal SiC Substrates by CVD and VLS." Materials Science Forum 556-557 (September 2007): 403–6. http://dx.doi.org/10.4028/www.scientific.net/msf.556-557.403.

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We report an optical investigation of cubic Silicon Carbide (3C-SiC) layers grown on 6H-SiC substrates by Chemical Vapour Deposition and Vapour-Liquid-Solid mechanism. Micro- Infrared reflectance ('-IR), micro-Raman ('-Raman) and low temperature photoluminescence spectroscopies were used for the characterisation of such layers. '-IR measurements showed unusual optical behaviour of 3C-SiC layers. The difference of refraction index between the 3C-SiC film and the 6H-SiC substrate cannot explain this result. The experimental '-IR reflectance spectrum was modelled by introducing a thin (thickness ≤ 0.5 'm) metallic-like (doping ≥ 1020 at.cm-3) interfacial film between the layer and the substrate. The photoluminescence spectra revealed the presence of a peak which may be attributed to recombination at the 3C/6H interface. All these results suggest the presence of a two dimensional electron gas at the interface.

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Bassani, C., C. Manzo, F. Braga, M. Bresciani, C. Giardino, and L. Alberotanza. "Impact of the aerosol type on HICO™ atmospheric correction in coastal waters." Atmospheric Measurement Techniques Discussions 7, no. 5 (May 23, 2014): 5147–72. http://dx.doi.org/10.5194/amtd-7-5147-2014.

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Abstract. The aim of this work is to evaluate the radiative impact of the aerosol type on the results of the atmospheric correction of HICO™ (Hyperspectral Imager for the Coastal Ocean) hyperspectral data. The reflectance was obtained by using the HICO@CRI (HICO ATmospherically Corrected Reflectance Imagery) algorithm, a physically-based atmospheric correction algorithm developed specifically for HICO™ data by adapting the vector version of the Second Simulation of a Satellite Signal in the Solar Spectrum (6SV) radiative transfer code. The HICO@CRI algorithm was applied on six HICO™ images acquired in the Northern part of the Mediterranean Basin, using the micro-physical properties measured with a CIMEL sun sky-radiometer at the Acqua Alta Oceanographic Tower (AAOT) AERONET site and the optical properties of the maritime, continental, and urban aerosol types provided by default by the 6SV. The results highlight that the aerosol type can improve the accuracy of the atmospheric correction. Indeed, the accuracy of the water reflectance retrieved from the available HICO™ data decreases in the sensor spectral domain, considering the AERONET micro-physical properties, of 30% using the urban aerosol type, of 20% using the continental type, and finally of less than 10% assuming a maritime type. Thus, the aerosol type has to be taken into consideration in the atmospheric correction of hyperspectral data over coastal environment, if water quality analysis has to be performed, because of the influence of aerosol type on the water reflectance.

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Tang, Shu Ling, Da Zhen Tang, Hao Xu, Shu Tao, Yuan Fang, and Li Jun Gao. "Adsorption Characteristics of Different Stratification in the Coal Reservoirs of Southern Qinshui Basin and its Main Controlling Factors." Advanced Materials Research 915-916 (April 2014): 1103–7. http://dx.doi.org/10.4028/www.scientific.net/amr.915-916.1103.

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Based on previous measured data and adsorption isotherms experiment of six coal samples from different stratification of the southern Qinshui basin, discussed the diversity between different stratification on adsorption characteristics and its main controlling factors. The results show that: In the macro level, bright coal layer has the highest adsorption capacity, Langmuir volume (VL) is up to 40m3/t ; the adsorption capacity of dull coal and semi-dull coal is relatively low. By analyzing the relationship between the Langmuir volume of coal petrography and various factors, discovering the Langmuir volume has a positive correlation with vitrinite content, vitrinite reflectance, fixed carbon content, and micro-pores content, but negative correlation with ash, while it has no significant linear relationship between moisture, porosity, permeability. By grey relational analysis, it shows that the impact is in descending order from vitrinite content to fixed carbon content, vitrinite reflectance, micro-pores content, ash content.

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ZARROUG, AHMED, LOTFI DERBALI, RACHID OUERTANI, WISSEM DIMASSI, and HATEM EZZAOUIA. "COMBINED EFFECT OF MECHANICAL GROOVING AND STAIN-ETCHED SURFACE ON OPTICAL AND ELECTRICAL PROPERTIES OF CRYSTALLINE SILICON SUBSTRATES." Surface Review and Letters 21, no. 03 (June 2014): 1450041. http://dx.doi.org/10.1142/s0218625x14500413.

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This paper investigates the combined effect of mechanical grooving and porous silicon (PS) on the front surface reflectance and the electronic properties of crystalline silicon substrates. Mechanical surface texturization leads to reduce the cell reflectance, enhance the light trapping and augment the carrier collection probability. PS was introduced as an efficient antireflective coating (ARC) onto the front surface of crystalline silicon solar cell. Micro-periodic V-shaped grooves were made by means of a micro-groove machining process prior to junction formation. Subsequently, wafers were subjected to an isotropic potassium hydroxide ( KOH ) etching so that the V-shape would be turned to a U-shape. We found that the successive treatment of silicon surfaces with stain-etching, grooving then alkaline etching enhances the absorption of the textured surface, and decreases the reflectance from 35% to 7% in the 300–1200 nm wavelength range. We obtained a significant increase in the overall light path that generates the building up of the light trapping inside the substrate. We found an improvement in the illuminated I–V characteristics and an increase in the minority carrier lifetime τeff. Such a simple method was adopted to effectively reinforce the overall device performance of crystalline silicon-based solar cells.

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Choi, Gyu-Jong, Hwa-Young Kim, and Jung-Hwan Ahn. "Study on Algorithm of Micro Surface Roughness Measurement Using Laser Reflectance Light." Transactions of the Korean Society of Mechanical Engineers A 32, no. 4 (April 1, 2008): 347–53. http://dx.doi.org/10.3795/ksme-a.2008.32.4.347.

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Lastras-Martínez, L. F., R. Herrera-Jasso, N. A. Ulloa-Castillo, R. E. Balderas-Navarro, A. Lastras-Martínez, Angie C. Lin, M. M. Fejer, and James S. Harris. "Optical characterization of orientation-patterned GaP structures by micro reflectance difference spectroscopy." Journal of Applied Physics 114, no. 17 (November 7, 2013): 173504. http://dx.doi.org/10.1063/1.4828737.

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Zhou, Qin, Xianming Xiao, Lei Pan, and Hui Tian. "The relationship between micro-Raman spectral parameters and reflectance of solid bitumen." International Journal of Coal Geology 121 (January 2014): 19–25. http://dx.doi.org/10.1016/j.coal.2013.10.013.

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Dal Fovo, Alice, Marina Martínez-Weinbaum, Mohamed Oujja, Marta Castillejo, and Raffaella Fontana. "Reflectance Spectroscopy as a Novel Tool for Thickness Measurements of Paint Layers." Molecules 28, no. 12 (June 9, 2023): 4683. http://dx.doi.org/10.3390/molecules28124683.

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A major challenge in heritage science is the non-invasive cross-sectional analysis of paintings. When low-energy probes are used, the presence of opaque media can significantly hinder the penetration of incident radiation, as well as the collection of the backscattered signal. Currently, no technique is capable of uniquely and noninvasively measuring the micrometric thickness of heterogeneous materials, such as pictorial layers, for any painting material. The aim of this work was to explore the possibility of extracting stratigraphic information from reflectance spectra obtained by diffuse reflectance spectroscopy (DRS). We tested the proposed approach on single layers of ten pure acrylic paints. The chemical composition of each paint was first characterised by micro-Raman and laser-induced breakdown spectroscopies. The spectral behaviour was analysed by both Fibre Optics Reflectance Spectroscopy (FORS) and Vis-NIR multispectral reflectance imaging. We showed that there is a clear correlation between the spectral response of acrylic paint layers and their micrometric thickness, which was previously measured by Optical Coherence Tomography (OCT). Based on significant spectral features, exponential functions of reflectance vs. thickness were obtained for each paint, which can be used as calibration curves for thickness measurements. To the best of our knowledge, similar approaches for cross-sectional measurements of paint layers have never been tested.

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Pontes, F. M., S. H. Leal, P. S. Pizani, M. R. M. C. Santos, E. R. Leite, E. Longo, F. Lanciotti, T. M. Boschi, and J. A. Varela. "Structural phase evolution of strontium-doped lead titanate thin films prepared by the soft chemical technique." Journal of Materials Research 18, no. 3 (March 2003): 659–63. http://dx.doi.org/10.1557/jmr.2003.0087.

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Strontium-modified lead titanate thin films with composition Pb1−xSrxTiO3 were grown on Pt/Ti/SiO2/Si substrates using the polymeric precursor method. The structural phase evolution as a function of the Sr contents was studied using micro-Raman scattering, specular reflectance infrared Fourier transform spectroscopy, and x-ray diffraction. The results showed a gradual change from tetragonal to cubic structure, the transition occurring at about x = 0.58. The infrared reflectance spectra showed that the frequency of several peaks decreases as the strontium concentration increases. These features are correlated with a decrease in the tetragonal distortion of the TiO6 octahedra as the strontium concentration increases.

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SARKAR, ADITI, ARNAB GANGOPADHYAY, and A. SARKAR. "LEFT-HANDED MAXWELLIAN BEHAVIOR OF NATURAL MICA." Modern Physics Letters B 25, no. 30 (November 21, 2011): 2323–33. http://dx.doi.org/10.1142/s0217984911027534.

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In this work, meta-material like behavior of natural Mica are studied. This work makes an attempt to analyze the left-handed Maxwellian (LHM) properties of Mica. The investigations carried out on natural Mica specimen are optical reflectance, optical absorbance and DC current–voltage-characteristics (CVC). Optical reflectance of Mica sheet with plane polarized monochromatic light shows distinct difference with conventional theoretical results. The DC CVC also measured with complete electromagnetic shielding. There exists a clear difference in DC characteristic for presence and absence of stray electromagnetic fields. The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-VIS) analysis are also carried out for further analysis. The results obtained from the optical reflectance characteristics using polarized light indicate LHM behavior as may be found in a meta-material. Micro-structural and electrical analysis shows that it is a nano-structured layered material.

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Arslan, Halil, and Yasar Baris Dolukan. "Determination of the optical properties of bovine liver tissue using integrating sphere technique." Academic Perspective Procedia 1, no. 1 (November 9, 2018): 248–52. http://dx.doi.org/10.33793/acperpro.01.01.46.

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The optical properties (absorption and reduced scattering coefficients, &micro;a and &micro;s&rsquo;) of bovine liver tissue for 635 nm has been determined by using integrating sphere and inverse adding-doubling (IAD) techniques. For this purpose, total reflectance and total transmittance values of bovine liver tissue sample, which is placed between two microscope slides, have been measured by using single-sphere system. The measured values have been used as input parameters for IAD program to extract the &micro;a and &micro;s&rsquo; of the sample. In this study, &micro;a and &micro;s&rsquo; of bovine liver tissue for 635 nm have been determined to be 0.22 mm-1 and 0.51mm-1, respectively. These values, which yield 1.44 mm penetration depth, are in good agreement with the ones in the literature.

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Revelo-Luna, David, Aldemar Reyes-Trujillo, and Miguel Peña-Varón. "Spectral and thermal response of Heliconia psittacorum species to induced water stress." Agronomía Colombiana 36, no. 3 (September 1, 2018): 237–47. http://dx.doi.org/10.15446/agron.colomb.v36n3.70379.

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An important limitation in agricultural production is stress resulting from water deficit. Flower production and postharvest life both decrease in Heliconia psittacorum affected by water stress. Remote sensing provides tools for estimating the water status of plant species using spectral information in the visible and infrared range. This paper presents a study of reflectance in the 350-800 nm range and the response in the thermal infrared of leaf tissue under different irrigation regimes. For the measurement of reflectance, an OceanOptics® Micro-Spectrometer was used, while for the thermal infrared measurements, a FLIRE40® camera was used. Three irrigation regimes were established: T1: 100% field capacity (FC), T2: 50% FC, and T3: 10% FC. Significant differences were found between treatment T1 and treatments T2-T3 in the water stress index (CWSI) and stomatal conductance index (GI). The reflectance around 800 nm decreased for T2 and T3. Significant differences were obtained between T1 and T2-T3 in the maximum of the first derivative of the reflectance between 700 and 750 nm. It was found that, in the range 350-800 nm, the thermal indices were better indicators of the water status of the Heliconia species than the spectral indices.

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Yin, Jingbo, Huangping Yan, Rui Zhou, Yuanzhe Li, and Anna He. "Thermal-Assisted Laser Fabrication of Broadband Ultralow Reflectance Surface by Combining Marangoni Flow with In Situ Deposition." Nanomaterials 13, no. 3 (January 25, 2023): 480. http://dx.doi.org/10.3390/nano13030480.

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Functional surfaces with broadband ultralow optical reflectance have many potential applications in the fields of enhancing solar energy utilization, stray light shielding, infrared stealth, and so on. To fabricate broadband anti-reflection surfaces with low cost, high quality, and more controllability, a strategy of preparing multi-scale structures by thermal-assisted nanosecond laser was proposed. This strategy combines laser ablation with Marangoni flow of molten materials and in situ deposition of nanoparticles. The thermal-assisted strategy increases the depth to width ratio of the anti-reflection structures. The average reflectance of laser-textured TC4 (Ti-6Al-4V) surface is as low as 1.71% in the wavelength range of 200–2250 nm and 7.8% in the 2500–25,000 nm. The ultra-low reflectance surface has a significantly enhanced photothermal conversion performance. Meanwhile, the anti-reflection effect can be extended to the mid-infrared band, which has potential stealth application prospect. This synergetic manufacturing strategy has wide adaptability of materials, which provides new paths for the preparation of broadband ultralow reflectance surface. Moreover, this thermal-assisted laser fabrication strategy is prospective in the preparation of other functional micro-nano structures.

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Zhu, Yihua, Chung Ng, Oanh Le, Yi-Ching Ho, and Daniel Fried. "Diagnostic Performance of Multispectral SWIR Transillumination and Reflectance Imaging for Caries Detection." Diagnostics 13, no. 17 (August 31, 2023): 2824. http://dx.doi.org/10.3390/diagnostics13172824.

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The aim of this clinical study was to compare the diagnostic performance of dual short wavelength infrared (SWIR) occlusal transillumination and reflectance multispectral imaging with conventional visual assessment and radiography for caries detection on premolars scheduled for extraction for orthodontics reasons. Polarized light microscopy (PLM) and micro-computed tomography (microCT) performed after tooth extraction were used as gold standards. The custom-fabricated imaging probe was 3D-printed and the imaging system employed a SWIR camera and fiber-optic light sources emitting light at 1300 nm for occlusal transillumination and 1600 nm for reflectance measurements. Teeth (n = 135) on 40 test subjects were imaged in vivo using the SWIR imaging prototype in the study and teeth were extracted after imaging. Our study demonstrates for the first time that near-simultaneous real-time transillumination and reflectance video can be successfully acquired for caries detection. Both SWIR imaging modalities had markedly higher sensitivity for lesions on proximal and occlusal surfaces compared to conventional methods (visual and radiographic). Reflectance imaging at 1600 nm had higher sensitivity and specificity than transillumination at 1300 nm. The combined SWIR methods yielded higher specificity but the combined sensitivity was lower than for each individual method.

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Lou, Rui, Guangying Li, Xu Wang, Wenfu Zhang, Yishan Wang, Guodong Zhang, Jiang Wang, and Guanghua Cheng. "Antireflective and Superhydrophilic Structure on Graphite Written by Femtosecond Laser." Micromachines 12, no. 3 (February 26, 2021): 236. http://dx.doi.org/10.3390/mi12030236.

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Antireflection and superhydrophilicity performance are desirable for improving the properties of electronic devices. Here, we experimentally provide a strategy of femtosecond laser preparation to create micro-nanostructures on the graphite surface in an air environment. The modified graphite surface is covered with abundant micro-nano structures, and its average reflectance is measured to be 2.7% in the ultraviolet, visible and near-infrared regions (250 to 2250 nm). The wettability transformation of the surface from hydrophilicity to superhydrophilicity is realized. Besides, graphene oxide (GO) and graphene are proved to be formed on the sample surface. This micro-nanostructuring method, which demonstrates features of high efficiency, high controllability, and hazardous substances zero discharge, exhibits the application for functional surface.

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Zhang, Qiang, Yongguang Zhao, Lei Zhang, Jiaqi Wu, Wan Li, Jun Yan, Xiaohua Jiang, Zhiyu Yan, and Jing Zhao. "On-Orbit Radiometric Calibration of Hyperspectral Sensors on Board Micro-Nano Satellite Constellation Based on RadCalNet Data." Remote Sensing 14, no. 19 (September 21, 2022): 4720. http://dx.doi.org/10.3390/rs14194720.

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The stability and accuracy of the on-orbit radiometric calibration of hyperspectral sensors are prerequisites for the quantitative application of satellite hyperspectral data. The Zhuhai-1 micro-nano satellite constellation is composed of eight hyperspectral satellite missions. The Orbita Hyperspectral Sensor (OHS) on board each satellite has a gradient filter spectroscopic design. When observing the Earth, eight integration stages can be set for each band according to different lighting conditions. Due to high manufacturing costs, OHSs are not equipped with on-board calibration devices. Therefore, it is very difficult to accurately calibrate OHSs for all of the integration stages. On the other hand, it is extremely important to ensure radiometric consistency between different OHSs within the Zhuhai-1 micro-nano satellite constellation. To carry out the rapid radiometric calibration of the Zhuhai-1 constellation, an on-orbit radiometric calibration model considering all of the integration stages related to hyperspectral sensors was built based on the BOA reflectance and atmosphere parameters published by the Committee on Earth Observation Satellites (CEOS) radiometric calibration network (RadCalNet). The RadCalNet product was used to derive the TOA radiance base in the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) radiative transfer (RT) model. In this paper, we analyzed the radiometric stability of the same sensor and the consistency of different calibration results regarding four RadCalNet sites, and the on-orbit radiometric performance evaluation of OHSs was also carried out. The data retrieved from OHSs regarding hyperspectral surface reflectance were preliminarily validated using site-synchronous surface reflectance measurements.

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Wang, Weng Ju, Shu Guang Zhu, Jie Wang, and Xin Zhi Liu. "Synthesis of Micro-Mesoporous Titanium-Silicon Molecular Sieve by Dual Templates Method." Advanced Materials Research 560-561 (August 2012): 791–96. http://dx.doi.org/10.4028/www.scientific.net/amr.560-561.791.

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Micro-mesoporous titanium-silicon molecular sieve (MMTS) was synthesized through dual templates method. The physical characterization of MMTS was carried out by BET, FTIR, UV-Vis. The results showed that the MMTS samples synthesized by dual templates method possessed mainly micropores and some mesopores with pore size of 3.9 nm, but a portion of the titanium in the framework was removed as indicated from UV-Vis diffuse reflectance spectroscopy.

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Tan, Xiao, Zhi Tao, Mingxing Yu, Hanxiao Wu, and Haiwang Li. "Anti-Reflectance Optimization of Secondary Nanostructured Black Silicon Grown on Micro-Structured Arrays." Micromachines 9, no. 8 (August 2, 2018): 385. http://dx.doi.org/10.3390/mi9080385.

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Owing to its extremely low light absorption, black silicon has been widely investigated and reported in recent years, and simultaneously applied to various disciplines. Black silicon is, in general, fabricated on flat surfaces based on the silicon substrate. However, with three normal fabrication methods—plasma dry etching, metal-assisted wet etching, and femtosecond laser pulse etching—black silicon cannot perform easily due to its lowest absorption and thus some studies remained in the laboratory stage. This paper puts forward a novel secondary nanostructured black silicon, which uses the dry-wet hybrid fabrication method to achieve secondary nanostructures. In consideration of the influence of the structure’s size, this paper fabricated different sizes of secondary nanostructured black silicon and compared their absorptions with each other. A total of 0.5% reflectance and 98% absorption efficiency of the pit sample were achieved with a diameter of 117.1 μm and a depth of 72.6 μm. In addition, the variation tendency of the absorption efficiency is not solely monotone increasing or monotone decreasing, but firstly increasing and then decreasing. By using a statistical image processing method, nanostructures with diameters between 20 and 30 nm are the majority and nanostructures with a diameter between 10 and 40 nm account for 81% of the diameters.

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Szydłowski, Michał, Bartosz Powałka, Marcin Matuszak, and Paweł Kochmański. "Machine vision micro-milling tool wear inspection by image reconstruction and light reflectance." Precision Engineering 44 (April 2016): 236–44. http://dx.doi.org/10.1016/j.precisioneng.2016.01.003.

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Ojeda, Jesús J., María E. Romero-González, and Steven A. Banwart. "Analysis of Bacteria on Steel Surfaces Using Reflectance Micro-Fourier Transform Infrared Spectroscopy." Analytical Chemistry 81, no. 15 (August 2009): 6467–73. http://dx.doi.org/10.1021/ac900841c.

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46

Choudhary, R. B., O. S. Tyagi, and O. N. Anand. "FTIR micro-reflectance absorption spectroscopic analysis of chemisorbed reaction films for tribological applications." Lubrication Science 27, no. 6 (January 14, 2015): 381–96. http://dx.doi.org/10.1002/ls.1288.

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Yang, Lan Tian. "Hybrid Microstructures on Si Surface Formed by Nanosecond Pulse Laser for Broadband Antireflection." Advanced Materials Research 983 (June 2014): 84–89. http://dx.doi.org/10.4028/www.scientific.net/amr.983.84.

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In this paper, a hybrid quasi-micro-pyramid structure is fabricated via nanosecond pulse laser micro-processing, which demonstrates a 15% drop in average reflectance as compared to the uniform quasi-micro-pyramid structures. The influences of laser fluence, pulse number, and designed pitch are also studied experimentally and systematically. The results show that reflection increases with the pattern pitch, decreases with pulse number, and a minimum in reflection is reached at a laser fluence of 4.83 J/cm2. The method here demonstrated provides an alternative and low-cost solution for broadband anti-reflection by hybrid structures with normal aspect ratio rather than uniform structures with high aspect ratio. Higher antireflection performance can be expected by optimizing the laser processing parameters.

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Tirelli, C., C. Manzo, G. Curci, and C. Bassani. "EVALUATION OF THE AEROSOL TYPE EFFECT ON THE SURFACE REFLECTANCE RETRIEVAL USING CHRIS/PROBA IMAGES OVER LAND." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-7/W3 (April 30, 2015): 1311–16. http://dx.doi.org/10.5194/isprsarchives-xl-7-w3-1311-2015.

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Surface reflectance has a central role in the analysis of land surface for a broad variety of agricultural, geological and urban studies. An accurate atmospheric correction, obtained by an appropriate selection of aerosol type and loading, is the first requirement for a reliable surface reflectance estimation. The aerosol type is defined by its micro-physical properties, while the aerosol loading is described by optical thickness at 550 nm. The aim of this work is to evaluate the radiative impact of the aerosol model on the surface reflectance obtained from CHRIS (Compact High Resolution Imaging Spectrometer) hyperspectral data over land by using the specifically developed algorithm CHRIS@CRI (CHRIS Atmospherically Corrected Reflectance Imagery) based on the 6SV radiative transfer model. Five different aerosol models have been used: one provided by the AERONET inversion products (used as reference), three standard aerosol models in 6SV, and one obtained from the output of the GEOS-Chem global chemistry-transport model (CTM). As test case the urban site of Bruxelles and the suburban area of Rome Tor Vergata have been considered. The results obtained encourages the use of CTM in operational retrieval and provides an evaluation of the role of the aerosol model in the atmospheric correction process, considering the different microphysical properties impact.

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Boehmler, Jayne, S. Loría-Salazar, Chris Stevens, James Long, Adam Watts, Heather Holmes, James Barnard, and W. Arnott. "Development of a Multispectral Albedometer and Deployment on an Unmanned Aircraft for Evaluating Satellite Retrieved Surface Reflectance over Nevada’s Black Rock Desert." Sensors 18, no. 10 (October 17, 2018): 3504. http://dx.doi.org/10.3390/s18103504.

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Bright surfaces across the western U.S. lead to uncertainties in satellite derived aerosol optical depth (AOD) where AOD is typically overestimated. With this in mind, a compact and portable instrument was developed to measure surface albedo on an unmanned aircraft system (UAS). This spectral albedometer uses two Hamamatsu micro-spectrometers (range: 340–780 nm) for measuring incident and reflected solar radiation at the surface. The instrument was deployed on 5 October 2017 in Nevada’s Black Rock Desert (BRD) to investigate a region of known high surface reflectance for comparison with albedo products from satellites. It was found that satellite retrievals underestimate surface reflectance compared to the UAS mounted albedometer. To highlight the importance of surface reflectance on the AOD from satellite retrieval algorithms, a 1-D radiative transfer model was used. The simple model was used to determine the sensitivity of AOD with respect to the change in albedo and indicates a large sensitivity of AOD retrievals to surface reflectance for certain combinations of surface albedo and aerosol optical properties. This demonstrates the need to increase the number of surface albedo measurements and an intensive evaluation of albedo satellite retrievals to improve satellite-derived AOD. The portable instrument is suitable for other applications as well.

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Borg, Braeden, Michelle Dunn, Andrew S. M. Ang, and Carl Villis. "Canvas Painting Analysis Using Spectroscopic Analysis and Microcharacterisation Techniques." Sensors 22, no. 4 (February 13, 2022): 1442. http://dx.doi.org/10.3390/s22041442.

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Raman spectroscopy is a well-recognised tool for the analysis of materials in canvas paintings. However, it can be difficult to interpret the peaks of the spectra without the additional context of the artwork such as the age, provenance, or colour. Reflectance spectrophotometry can be used to capture the colour of pigments, dyes, and lacquers, but is seldom used to complement Raman data. Additionally, reflectance spectrophotometry results can be influenced by the surface profile of the painting. To overcome these limitations, this work brings together three different analysis modalities to provide a singular, analytical map of the artwork. Raman spectroscopy was used to conduct the chemical identification of pigments, binding media, and varnish present in a synthetic painting sample. Reflectance spectrophotometry was applied to obtain colour information of the surface paint of the sample. Three-dimensional optical profilometry data was used to characterise the micro topology of the paint surface. These three data sets were spatially matched allowing the recorded spectroscopic data to be displayed with the corresponding colour and surface topography across the paint surface.

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Journal articles on the topic 'Micro-reflectance'

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