Selective Radiation Properties of Particulate Coatings

1963 ◽  
Vol 85 (3) ◽  
pp. 213-220 ◽  
Author(s):  
D. A. Williams ◽  
T. A. Lappin ◽  
J. A. Duffie
Keyword(s):  
Optical Properties ◽  
Radiation Properties ◽  
High Fraction ◽  
Energy Absorbers ◽  
Coated Surfaces ◽  
Particulate Coatings ◽  
Aluminum Substrates ◽  
Coating Weight ◽  
Theoretical Considerations ◽  
Better Than

The variation with wavelength of thermal radiation properties of coated surfaces is important for solar energy absorbers and in other applications, and depends on the optical properties of the coating material and the substrate, and on the structure of the coating. Theoretical considerations indicate that, for homogeneous coatings, the good optical properties of semiconductors can be improved if the coating contains a high fraction of voids. This improvement has been shown by experimental particulate PbS coatings which are not homogeneous; the selective properties of particulate coatings are better than those calculated for solid coatings at the same coating weight. PbS coatings on aluminum substrates show absorptances for solar radiation of 0.9 and long wave emittance of 0.2 to 0.3. The feasibility of selective paints has been demonstrated; PbS can be mixed with a transparent binder, silicone, to make a paint which shows a good degree of selectivity, and absorptances of 0.9 and emittances less than 0.4 have been obtained.

Study on Optical Properties of Microstructure of Lightguiding Plate for Micro Injection Molding and Micro Injection-Compression Molding

2006 ◽  
Vol 505-507 ◽  
pp. 229-234 ◽  
Author(s):  
Yung Kang Shen ◽  
H.J. Chang ◽  
C.T. Lin
Keyword(s):  
Optical Properties ◽  
Injection Molding ◽  
Digital Camera ◽  
Mold Temperature ◽  
Compression Molding ◽  
Micro Injection Molding ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Injection Compression Molding ◽  
Better Than

The purpose of this paper presents the optical properties of microstructure of lightguiding plate for micro injection molding (MIM) and micro injection-compression molding (MICM). The lightguiding plate is applied on LCD of two inch of digital camera. Its radius of microstructure is from 100μm to 300μm by linearity expansion. The material of lightguiding plate uses the PMMA plastic. This paper uses the luminance distribution to make a comparison between MIM and MICM for the optical properties of lightguiding plate. The important parameters of process for optical properties are the mold temperature, melt temperature and packing pressure in micro injection molding. The important parameters of process for optical properties are the compression distance, mold temperature and compression speed in micro injection-compression molding. The process of micro injection-compression molding is better than micro injection molding for optical properties.

scholarly journals Validation and Comparison of MODIS C6.1 and C6 Aerosol Products over Beijing, China

2018 ◽  
Vol 10 (12) ◽  
pp. 2021 ◽  
Author(s):  
Xinpeng Tian ◽  
Qiang Liu ◽  
Xiuhong Li ◽  
Jing Wei
Keyword(s):  
Optical Properties ◽  
Urban Areas ◽  
Surface Characteristics ◽  
Complex Surface ◽  
Deep Blue ◽  
Spatial Coverage ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Beijing China ◽  
Better Than

The operational Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Products (APs) have provided long-term and wide-spatial-coverage aerosol optical properties across the globe, such as aerosol optical depth (AOD). However, the performance of the latest Collection 6.1 (C6.1) of MODIS APs is still unclear over urban areas that feature complex surface characteristics and aerosol models. The aim of this study was to validate and compare the performance of the MODIS C6.1 and C6 APs (MxD04, x = O for Terra, x = Y for Aqua) over Beijing, China. The results of the Dark Target (DT) and Deep Blue (DB) algorithms were validated against Aerosol Robotic Network (AERONET) ground-based observations at local sites. The retrieval uncertainties and accuracies were evaluated using the expected error (EE: ±0.05 + 15%) and the root-mean-square error (RMSE). It was found that the MODIS C6.1 DT products performed better than the C6 DT products, with a greater percentage (by about 13%–14%) of the retrievals falling within the EE. However, the DT retrievals collected from two collections were significantly overestimated in the Beijing region, with more than 64% and 48% of the samples falling above the EE for the Terra and Aqua satellites, respectively. The MODIS C6.1 DB products performed similarly to the C6 DB products, with 70%–73% of the retrievals matching within the EE and estimation uncertainties. Moreover, the DB algorithm performed much better than DT algorithm over urban areas, especially in winter where abundant missing pixels were found in DT products. To investigate the effects of factors on AOD retrievals, the variability in the assumed surface reflectance and the main optical properties applied in DT and DB algorithms are also analyzed.

Beobachtungen zum Stofftransport und zu einhergehenden Schädigungseffekten in porösen Baustoffen / Observations of mass transport and related deterioration mechanisms in porous building materials

2000 ◽  
Vol 6 (4) ◽  
pp. 451-462 ◽  
Author(s):  
L. Franke ◽  
R. Reimann-Oenel
Keyword(s):  
Building Materials ◽  
Life Time ◽  
Water Repellent ◽  
Historic Buildings ◽  
Time Behaviour ◽  
Long Time Behaviour ◽  
Long Time ◽  
Natural Stones ◽  
Coated Surfaces ◽  
Theoretical Considerations

Abstract It is reported about substance migration problems and their consequences, which have been investigated experimentally and which could be particularly relevant with regard to repair and restoration of historic buildings. One aim of the investigations was to find out, whether facades, treated with water repellent agents, showing non treated areas, can be affected in their long time behaviour. Such lacks can be due to non careful application of the repellent agent. In addition, investigations were made to find out. of coatings on salt containing mineral substrates, especially natural stones can reduce their life time. As a result of the experiments and the theoretical considerations, it follows, that a lack in water repellent treatment. could cause the risk of crust-development spallings in environment of non treated spots in the case that substrate is salt contaminated and moisture exchange takes place. All experiments with coatings, performed under the same conditions, show, that the coated surfaces have a more favourable behaviour than the same surfaces without coatings.

Ion-Assisted Deposition of CaF2 Films on (111) Si

1992 ◽  
Vol 268 ◽  
Author(s):  
J.G. Cook ◽  
H. Moeller ◽  
S.R. Das ◽  
Li Zhongming
Keyword(s):  
Optical Properties ◽  
Emission Spectroscopy ◽  
Rf Discharge ◽  
Electrical And Optical Properties ◽  
Sputter Deposited ◽  
Deposited Films ◽  
Better Than

ABSTRACTCaF2 films have been deposited by evaporation onto H-passivated (111) Si in the presence of an rf discharge. The discharge is seen to promote epitaxy. Emission spectroscopy reveals strong CaF2 bands and a weak Ca line, indicating that deposition is largely molecular but that some breakup of the CaF2 molecules occurs in the discharge. Electrical and optical properties of these films were substantially better than those of sputter-deposited films.

The Study of Electronic Density of States and Optical Properties of ZnO Nanotube by First-Principles

2015 ◽  
Vol 713-715 ◽  
pp. 2966-2969
Author(s):  
Yue Fan ◽  
Shao Chang Chen
Keyword(s):  
Optical Properties ◽  
Fermi Level ◽  
Density Of States ◽  
First Principles ◽  
Electronic Density ◽  
Electronic Density Of States ◽  
Zno Nanotube ◽  
Narrow Energy Range ◽  
Wide Energy ◽  
Better Than

In this paper, we studied the electronic density of states (DOS) and optical properties ZnO using first-principles method. We find that the electronic density of states was different in bulk ZnO and ZnO nanotube. The DOS of bulk ZnO spread at wide energy while the DOS of ZnO nanotube concentrated in a narrow energy range. The peak around-18 eV moved to a higher energy. The peaks more than Fermi level concentrated to the Fermi level, which meant the conductivity of ZnO nanotube was better than that of bulk ZnO. We also calculated the optical properties of ZnO nanotube. The optical properties showed that there were peaks around 8 eV, which may come from electrons transition between Zn 3dand O 2pstates. Our calculation provided a reference for the application of ZnO nanotube in optical devices.

scholarly journals Development of PosMAC® Steel and Its Application Properties

2021 ◽  
Vol 59 (9) ◽  
pp. 613-623
Author(s):  
Il-Ryoung Sohn ◽  
Tae-Chul Kim ◽  
Gwang-Il Ju ◽  
Myung-Soo Kim ◽  
Jong-Sang Kim
Keyword(s):  
Corrosion Protection ◽  
Surface Friction ◽  
Chemical Compositions ◽  
Corrosion Performance ◽  
Corrosion Properties ◽  
Friction Resistance ◽  
Superior Surface ◽  
Coated Surfaces ◽  
Corrosive Environments ◽  
Coating Weight

PosMAC® is a hot dipping Zn-Mg-Al coated steel sheet developed by POSCO. PosMAC®3.0 shows excellent anti-corrosion performance and is suitable for construction and solar energy systems in severe corrosive environments. PosMAC®1.5 has a superior surface quality and is preferred for automotive and home appliances. The advanced anti-corrosion properties of PosMAC® comes from a dense corroded layer which forms on coated surfaces, compared with traditional Zn coatings such as GI, GA and EG. PosMAC® steels show superior corrosion protection compared to GI coatings in cyclic corrosion tests, despite an approximate 30% reduction in coating weight. The PosMAC® has excellent application properties for the arc welding of automotive chassis. It has a heat resistance that is more robust than the GI coating, and maintains excellent corrosion protection near the welds of the chassis. Zn-Mg-Al coatings, whose chemical compositions are similar to PosMAC® coatings, have very low surface friction properties compared to the GI coating. The friction coefficient of PosMAC® is stabilized to 0.09~0.11. In contrast, the GI coating showed higher friction coefficients of 0.2~0.3 in the repeated friction test. PosMAC® would be appropriate for complex forming parts with less galling, given these low friction resistance properties. It is expected that the industrial demand for PosMAC® steel will increase in the near future, thanks to its Zn saving and high anti-corrosion performance.

scholarly journals Choosing Filters to Make CCD Photometry Transformable to Other Detectors

1995 ◽  
Vol 167 ◽  
pp. 145-156
Author(s):  
Andrew T. Young
Keyword(s):  
Hilbert Space ◽  
Optical Properties ◽  
Spectral Response ◽  
Design Criteria ◽  
Ccd Photometry ◽  
General Transformation ◽  
The Common ◽  
Calibration Laboratories ◽  
Better Than ◽  
Space Approach

Transforming CCD data is difficult. Until recently, the general transformation problem was so poorly understood that there were no established design criteria. Now, the Hilbert-space approach to photometry tells us to match the standard passbands in the least-squares sense.Unfortunately, the spectral responsivities of CCDs vary much more than do conventional detectors, and must be known to design filters. Each individual chip generally requires its own set of filters, if results are to be better than second-rate. Even so, spatial variations in spectral response limit the accuracy that can be reached, unless color terms are determined for individual pixels. Such CCD calibration problems involve the generally neglected optical properties of CCDs and the systems in which they are used.Large observatories will have to establish calibration laboratories, and to abandon the common practice of moving “standard” filter sets from one instrument to another. Smaller institutions will need to purchase the services of such calibration laboratories if they are to produce accurate CCD photometry. These are major changes in the way astronomers are accustomed to working; but such changes are necessary to stem the backlash developing against CCD photometry.

scholarly journals The structure and optical properties of lead-free transparent KNLTN-La0.01 ceramics prepared by conventional sintering technique

2014 ◽  
Vol 32 (4) ◽  
pp. 597-603
Author(s):  
W. Yang ◽  
H. Xiu ◽  
Y. Xiong ◽  
J. Wang ◽  
C. Yuan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dispersion Model ◽  
Point Group ◽  
Lead Free ◽  
Dense Microstructure ◽  
Abo3 Perovskite ◽  
Conventional Sintering ◽  
Significant Wavelength ◽  
Perovskite Type ◽  
Better Than

Abstract(Na0.52K0.44Li0.04)0.97La0.01Ta0.20Nb0.80O3 (KNLTN-La0.01) lead-free subtransparent ceramics was prepared by a conventional sintering technique. The structure and the optical properties of the ceramics were investigated. The room temperature crystallographic indexing revealed the ABO3 perovskite type, tetragonal phase and P4mm point group in the ceramics. The surface and fractured surface SEM micrographs showed a dense microstructure with few micropores in KNLTN-La0.01 ceramics, which was obviously better than for the pure KNLTN ceramics. The refractive indexes of the films were investigated by an ellipsometer and the results show that the KNLTN-La0.01 subtransparent ceramics reveals significant wavelength dependent dispersion. The refractive index ranges from 2.14 to 2.06 with the wavelength increase from 380 nm to 900 nm. The dispersive behavior was analyzed by three parameters of Cauchy dispersion model and the values of the parameters A, B and C are 2.0610±0.0005, 0.0054±0.0003 and 0.00069±0.00004, respectively.

scholarly journals ELECTRONIC AND OPTICAL PROPERTIES OF C–N-CODOPED TiO2: A FIRST-PRINCIPLES GGA+U INVESTIGATION

2013 ◽  
Vol 27 (23) ◽  
pp. 1350123 ◽  
Author(s):  
MEILI GUO ◽  
JIULIN DU
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Wavelength Region ◽  
Light Response ◽  
Functional Theory ◽  
Long Wavelength ◽  
Visible Light Response ◽  
The Density Functional Theory ◽  
Better Than

Electronic structures and optical properties of C – N -codoped anatase TiO 2 were calculated by using GGA+U method based on the density functional theory. The calculated results showed that the N -doped, C -doped and C – N -codoped TiO 2 produced 2p states in band gap, and the band gaps of the three doped systems decreased compared with the pure TiO 2. According to the optical results, the band edges of the three doped systems shifted to the long wavelength region, and the visible optical absorption from 450 nm to 800 nm was observed. Moreover, the visible light response of C – N -codoped TiO 2 was better than the C or N single doped TiO 2, indicating that there was a synergistic effect for the C – N -codoped TiO 2, which offseted the deficiencies of C - or N -doped TiO 2.

scholarly journals Analysis of an Electrical Circuit Using Two-Parameter Conformable Operator in the Caputo Sense

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 771
Author(s):  
Ewa Piotrowska ◽  
Łukasz Sajewski
Keyword(s):  
Classical Method ◽  
Error Function ◽  
Electrical Circuit ◽  
Constant Voltage ◽  
Conformable Derivative ◽  
The One ◽  
Voltage Dynamics ◽  
Theoretical Considerations ◽  
Two Parameter ◽  
Better Than

The problem of voltage dynamics description in a circuit containing resistors, and at least two fractional order elements such as supercapacitors, supplied with constant voltage is addressed. A new operator called Conformable Derivative in the Caputo sense is used. A state solution is proposed. The considered operator is a generalization of three derivative definitions: classical definition (integer order), Caputo fractional definition and the so-called Conformable Derivative (CFD) definition. The proposed solution based on a two-parameter Conformable Derivative in the Caputo sense is proven to be better than the classical approach or the one-parameter fractional definition. Theoretical considerations are verified experimentally. The cumulated matching error function is given and it reveals that the proposed CFD–Caputo method generates an almost two times lower error compared to the classical method.

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