• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.513-520
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• 2000

An integrated grader which measures soluble solid content, color and weight of fresh apples was developed by NAMRI. The prototype grader consists of the near infrared spectroscopy and machine vision system. Image processing system and an algorithm to evaluate color were developed to speed up the color evaluation of apples. To avoid the light glare and specular reflection, an half-spherical illumination chamber was designed and fabricated to detect the color images of spherical-shaped apples more precisely. A color revision model based on neural network was developed. Near-infrared(NIR) spectroscopy system using NIR reflectance method developed by Lee et al(1998) of NAMRI was used to evaluate soluble solid content. In order to observe the performance of the grader, tests were conducted on conditions that there are 3 classes in weight sorting, 4 classes in combination of color and soluble solid content, and thus 12 classes in combined sorting. The average accuracy in weight, color and soluble solid content is more than about 90 % with the capacity of 3 fruits per second.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.3
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• pp.486-493
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• 2008

Safflower red colorants extracted by two solvents including the traditional ash solution and $K_{2}CO_{3}$ solution was used for dyeing cotton, ramie, viscose rayon, silk, wool, and nylon fabrics. The effects of extraction solvents on the reflectance, K/S value, and color properties of the dyed fabrics were investigated. Wash/dry cleaning and light colorfastness were evaluated. Reflectance curves of cotton, ramie, viscose rayon, and silk fabrics dyed with red colorants extracted by $K_{2}CO_{3}$ solution were similar, showing the maximum absorption at 520nm, to that of the dyed fabrics with red colorants extracted by ash solution. The reflectance curves of wool and nylon fabrics were different, showing the maximum absorption at 400nm. K/S values of dyed fabrics with red colorants extracted by $K_{2}CO_{3}$ solution were higher than that by ash solution with the exception of nylon. $L^{*},\;a^{*},\;b^{*}$, and $C^{*}$ of the dyed fabrics with red colorants extracted by $K_{2}CO_{3}$ solution were higher than that by ash solution except for $L^{*}$ of nylon and $b^{*}$ of viscose rayon. Color difference(${{\Delta}E}^*$) of the dyed fabrics between ash solution and $K_{2}CO_{3}$ solution increased in the order named as cotton, silk, ramie, viscose rayon, wool, and nylon. Regardless of extraction solvents, safflower red colorants produced RP color on cotton, ramie, and nylon, R color on viscose rayon and silk, and YR color on wool. Wash/dry cleaning fastness of the dyed fabrics was high above 3/4 rating but light fastness was very poor. It is considered that the use of $K_{2}CO_{3}$ solution instead of the traditional ash solution would be more effective in terms of color reproducibility and extraction process.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.189-194
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• 2012

Measurement of compositions and somatic cells in raw milk by chemical methods usually requires a lot of time, skilled labor and expensive analytical equipments. Recently, near-infrared reflectance spectroscopy (NIRS), which is a rapid, cost-effective and non-destructive technique, has been extensively used for safety and quality evaluation in the field of dairy products. However, less study has been performed to evaluate the effect of transmitted light on milk quality during NIRS analysis. Therefore, the objective of this study was to analyze the changes in milk quality using transmitted light. Raw milk samples collected from dairy farm from Siga prefecture in Japan were analyzed for fat, protein, lactose, solids not fat, total solids, milk urea and citric acid using the Milko scan 4000. Somatic cells in raw milk samples were counted by the Fossomatic 5000. Transmittance spectra of 50 ml raw milk samples were obtained by the Lax-Cute lighter in the 400 nm or less, 689 nm, 773 nm, 900 nm and 979 nm. As a result, milk fat as well as somatic cell count was increased by 2.6% and 9.0%, respectively. The other compositions were, however, changed within the relative error of the measurement. Further studies are needed to apply raw milk quality evaluation using the UV band by accumulating more samples and more data.

• Journal of the Korean Chemical Society
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• v.26 no.6
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• pp.369-377
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• 1982

The technique of combined-measurement of reflectance and ellipsometric parameters was used for studying the anodic film formed on nickel surface in basic solutions. An ellipsometer was automated for transient measurements by way of modulating the plane-polarized light with the Faraday effect. Surface film was formed electrochemically by applying a potential step from the reduction potential range to the passivation range on a polished, high-purity, polycrystalline nickel specimen. From that instant, the changes in the reflectance(r) and the ellipsometric parameters(${\Delta},{\Psi}$) of the surface film were recorded by the automatic ellipsometer. Three exact simultaneous equations including these optical signals, ${\Delta},{\Psi}$ and r were solved numerically with a computer in order to determine the optical properties, n, k, and the thickness, ${\tau}$, of the surface film. From the computed results which showed dependence on pH and time, it was found that passivation of nickel can be effectively attained by surface film thinner than $15{\AA}$ and this passivation film has a small optical absorption coefficient. It seemed that a high pH environment enhances the rate of passivation and is favorable for a denser structure of the surface film. The experimental evidence is in accordance with the hypothesis that the composition of the passive film can be approximated by $Ni(OH)_2$ in the early stage of passivation and that as time passes the composition changes partially toward that of NiO through dehydration.

• Journal of Technologic Dentistry
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• v.31 no.1
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• pp.23-36
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• 2009

The goal of esthetic restoration is to achieve morphologic, optical, and biologic acceptance. Creation of a natural looking ceramic restoration, which blends harmoniously with surrounding dentition, is not always achieved. A successful color match is an important aspect of any esthetic dental restoration. Since natural enamel has inherent translucency, it is important that ceramic restorations reproduce the translucency and color of the natural teeth. However, the final color match of porcelain crowns to adjacent natural dentition remains some problem. Difficulties related to color matching arise from the structural differences that exist between metal ceramic crowns and natural teeth, the limited range of available ceramic shades, inadequate shade guides, different types of metal alloys, repeated firing, the condensation technique, and varying compositions of ceramic materials. Many factors contribute to the esthetic success of dental restoration: optical properties such as color and its elements of hue, value, and chroma; translucency and opacity; light transmission and scattering; and metamerism and fluorescence. The purpose of this study was to determine the color changes of metal-ceramic system with different veneering porcelain powder after repeated firing. The objectives of this in vitro study were to measure the lightness($L^*$), chromaticity($a^*$), chromaticity($b^*$), chroma($C^*$), hue(h), reflectance(%), color difference(${\Delta}E$). The following conclusions were obtained: 1. An increase in the number of firings resulted in decrease in lightness($L^*$) but increase in chromacticity($a^*$) with all porcelain. After the second sintering resulted in decrease in chromacticity($b^*$) with opaque-dentin porcelain and dentin porcelain but in increase with enamel porcelain and translucency porcelain. And after the second sintering resulted in decrease in chroma($C^*$) with opaque-dentin porcelain and dentin porcelain, but on the whole side in decrease with enamel porcelain and translucency porcelain. 2. After the second firing, a increase in the number of firings resulted in decrease reflectance(%) in all wavelength. 3. There were noticeable color differences(${\Delta}E$) between first sintering and multiple firings(dentin porcelain: 5.29~8.15, opaque-dentin porcelain: 4.83~8.2, enamel porcelain: 8.93~13.15, translucency porcelain: 9.37~12.91), but the color difference(${\Delta}E$) after second sintering were down to 4.87 in all porcelain. 4. Given the NBS Criteria, a 'trace' was not found this study but a 'slight' was found 2-3, 3-5 in dentin porcelain, 2-3 in opaque-dentin porcelain, 3-5, 5-10 in enamel porcelain and translucency porcelain, a 'noticeable' was 2-5, 3-10, 5-10 in dentin porcelain and opaque-dentin porcelain, 2-3, 2-5, 3-10 in enamel porcelain 2-3, 3-10 in translucency porcelain, an 'appreciable' was 1-2, 1-3, 2-10 in dentin porcelain 1-2, 1-3, 2-10, 3-10 in opaque-dentin porcelain, 2-10 in enamel porcelain, 2-5, 2-10 in translucency porcelain, a 'much' was 1-5, 1-10 in dentin porcelain and opaque-dentin porcelain, 1-2, 1-3, 1-5 in enamel porcelain 1-2, 1-3, 1-5, 1-10 in translucency porcelain, a 'very much' was 1-10 in enamel porcelain.

• Journal of the Korean Ceramic Society
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• v.13 no.2
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• pp.24-30
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• 1976

To observe the influence of tetrahedral and octahedral preference of cations of Ni2+, Ti4+ upon the formation and the color development of the MgO-SnO2 spinel containing Ni2+ and Ti4+ ions, the gradual substitution of Ni2+ ions for Mg2+ ions and of Ti4+ ions for Sn4+ ions of the spinel in NiO-MgO-SnO2-TiO2 system was carried out. On samples prepared by calcining the oxide and basic carbonate mixtures at 130$0^{\circ}C$ for 1.5 hour, the X-ray analysis, measurement of reflectance and the test of their stability as a glaze pigment were also carried out. On samples prepared by calcining the oxide and basic carbonate mixtures at 130$0^{\circ}C$ for 1.5 hour, the X-ray analysis, measurement of reflectance and the test of their stabiality as a glaze pigment were also carried out. The results are summarized as follows. 1) As increasing the amounts of Ni2+ ions in the xNiO.(2-x)MgO.SnO2 system, spinel was not formed easily, and the mixed-spinel was formed in NiO.MgO.SnO2 of x=1 but the spinels was not formed completely in the range of x>1.5 2) The spinels was not more formed in NiO-MgO-TiO2 system than NiO-MgO-SnO2 system. Therefore, Ti4+ ions have strong octahedral preference than Sn4+ ions. The color changed the yellow region little. The mixed-spinel or non-spinel was formed easily NiO.TiO2, MgO.TiO2 of illmenite type as the gradual substitution of Ti4+ ions for Sn4+ ions. 3) The results of glaze test. The color changed from white through graish brown to brown as the gradual substitution of Ni2+ ions for Mg2+ ions in calcium-zinc glaze and calcium glaze, and from white through light yellowish beige to dull beige in tile glaze. Also, the color did not change generally as the gradual substitution of Ti4+ ions for Sn4+ ions in NiO-MgO-SnO2-TiO2 system.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.229-235
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• 1998

This paper reports the preparation and characterization of colored coatings of $SiO_2-TiO_2-M_xO_y$ (M = Co, Cr or Cu). Films of different compositions ranging from a molar content of transition metals of 5% to 20% have been prepared on soda-lime-silica slide glasses by the sol-gel process. The films have been characterized by a photospectroscopy. The color and reflectance of the films was expressed in Lab color chart and on spectra plot. 'L' as lightness and all reflectance decreased with increase of the content of transition metals. The coating of Co, Cu and Cr cotaining system showed light blue, green and lemon-yellowish color, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.345-346
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• 2013

InGaN material is being studied increasingly as a prospective material for solar cells. One of the merits for solar cell applications is that the band gap energy can be engineered from 0.7 eV for InN to 3.4 eV for GaN by varying of indium composition, which covers almost of solar spectrum from UV to IR. It is essential for better cell efficiency to improve not only the crystalline quality of the epitaxial layers but also fabrication of the solar cells. Fabrication includes transparent top electrodes and surface texturing which will improve the carrier extraction. Surface texturing is one of the most employed methods to enhance the extraction efficiency in LED fabrication and can be formed on a p-GaN surface, on an N-face of GaN, and even on an indium tin oxide (ITO) layer. Surface texturing method has also been adopted in InGaN-based solar cells and proved to enhance the efficiency. Since the texturing by direct etching of p-GaN, however, was known to induce the damage and result in degraded electrical properties, texturing has been studied widely on ITO layers. However, it is important to optimize the ITO thickness in Solar Cells applications since the reflectance is fluctuated by ITO thickness variation resulting in reduced light extraction at target wavelength. ITO texturing made by wet etching or dry etching was also revealed to increased series resistance in ITO film. In this work, we report a new way of texturing by deposition of thickness-optimized ITO films on ITO nano dots, which can further reduce the reflectance as well as electrical degradation originated from the ITO etching process.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.123-128
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• 1999

This paper reports the preparation and characterization of colored coatings of $Al_2O_3$-CoO. Films of 25mol% CoO doped $Al_2O_3$, have been prepared on soda-lime-silica slide glasses by the sol-gel process from Al-alkoxide and Co-nitrate. The films have been characterized by a photospectroscopy and hardness tester. The color, spectral reflectance and spectral transmittance of the films was expressed in Lab color chart and on spectra plot. Microhardness of the films increased with increasing of the heating temperature. Transmittance and reflectance of the films decreased with increase of the heating temperature and coating times. The coating films showed various light-yellow, deep-yellow, greenish-yellow color as a function of the coating times and heating temperature.

• Resources Recycling
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• v.18 no.4
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• pp.24-30
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• 2009

Rare earth based calcium aluminate phosphor ($CaAl_2O_4:Eu^{2+}$, $Nd^{3+}$) supported $TiO_2$ nanoparticles are synthesized by using sol-gel method, which are further characterized using powder X-ray diffraction (XRD), fourier transform infrared (FT-IR), diffuse reflectance UV-Visible spectroscopy (DRS UV-Vis) and transmission electron microscopy (TEM). The XRD pattern of as-prepared and sintered phosphor supported $TiO_2$ does not show the tendency to change the crystal structure from anatase to rutile phase up to $600^{\circ}C$. This indicates that the phosphor support might inhibit the densification and crystallite growth by providing dissimilar boundaries. The diffuse reflectance spectral (DRS) measurements showed shift towards longer wavelength indicating reduction in the band-gap energy as compared to free $TiO_2$. The FT-IR spectra of phosphor supported $TiO_2$ nanoparticles show shift in the peak positions to lower wavelengths. This indicates that the $TiO_2$ nanoparticles are not free, but covalently bonded to the phosphor support. TEM micrographs show presence of crystalline and spherical $TiO_2$ nanoparticles (8 - 15 nm diameter) dispersed uniformly on the surface of phosphor.