• Title/Summary/Keyword: polishing degree

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Enzymatic Activity of Liquid Nuruk according to Types of Nuruk Molds and Degree of Rice-polishing

  • Cho, Jae-Chul
    • Culinary science and hospitality research
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    • v.23 no.1
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    • pp.95-102
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    • 2017
  • This study was activity of ${\alpha}-amylase$, glucoamylase of liquid Nuruk prepared using liquid Nuruk (NK) and Aspergillus kawachii (AK), Aspergillus niger (AN), Aspergillus oryzae (AO), Monascus kaoliang (MK). To investigate the relationship between the enzymatic activity and the total sugar content of liquid Nuruk depending on the types of Nuruk molds and the degree of rice-polishing. The activity of ${\alpha}-amylase$ depending on the types of Nuruk molds was shown to be 8.82, 8.72 units/mL in AN and AK treatments in brown rice liquid Nuruk at 24 hours after incubation, as the degree of rice-polishing increased, the activity of ${\alpha}-amylase$ was significantly lower (p<0.05). When brown rice was incubated in AN, it showed 8.83 units/mL at 48 hours after incubation, which was the highest activity, but there was no significantly difference (p<0.05), as the degree of rice- polishing was higher, the activity of ${\alpha}-amylase$ was lower. The activity of glucoamylase depending on the degree of rice-polishing showed 3,013 units/mL in AO treatment in brown rice liquid Nuruk at 24 hours after incubation, and the enzymatic activity was significantly higher (p<0.05). As the degree of rice-polishing increased, the activity of glucoamylase decreased, so liquid brown rice Nuruk showed the highest enzymatic activity, liquid white rice Nuruk was the lowest enzymatic activity. The highest enzymatic activity appeared in liquid Nuruk with brown rice at 48 hours after incubation. The activity of ${\alpha}-amylase$, glucoamylase showed higher enzymatic productivity as the degree of rice-polishing was lower, and there was an inverse correlation with the total sugar content.

Physicochemical Properties and Hydration of Rice on Various Polishing Degrees (도정도에 따른 쌀의 수화와 이화학적 특성)

  • Kim, Kyung-Ae;Jeon, Eun-Ryae
    • Korean Journal of Food Science and Technology
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    • v.28 no.5
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    • pp.959-964
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    • 1996
  • The physicochemical and gelatinization properties of rice flours, which were prepared by polishing nonwaxy brown rice (Dongjin byeo), depending on polishing degrees were investigated. The contents of protein, ash, lipid and fiber decreased significantly as the degrees of polishing increased and water uptake of rice grains decreased during hydration. When the surface of the soaked rice grains was examined by the SEM, extensive crack formation was observed. The water binding capacities, swelling power and solubility of rice flour increased as the polishing degree increased. By the amylogram, the initial gelatinization temperatures of rice flour decreased as the polishing degree increased and the peak viscosities, the breakdown and consistency of rice flour increased as the polishing degree increased.

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Properties of Microemulsion Containing Quaternary Ammonium Salt as Polishing Wax (광택용 왁스로서 4차 암모늄염을 함유한 마이크로에멀젼의 특성)

  • Lee, Jang-Weon;Kim, Myung-Soo;Jeong, Noh-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.4
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    • pp.335-344
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    • 2004
  • In this work, the properties as polishing wax for automobile of O/W type microemulsion containing wax, liquid paraffine and quaternaryammonium salt was investigated. The microemulsions were prepared at $96{\sim}97^{\circ}C$ by the phase inversion method, and polyoxyethylene(20) sorbitan monooleate (POE(20)SMO) and distearyl dimethyl ammonium chloride(D.D.A.C) as the emulsifiers were used. The mean particle size of the rnicroemulsions was about 7${\pm}$0.5nm and as the properties of polishing wax, gloss increased degree, water resistant gloss degree, initial and final contact angle after water resistance were tested. The result was that the value of water resistantance and contact angle were decreased with increasing amount of POE(20)SMO and D.D.A.C., while the gloss degree values did not affected. And the rnicroemulsion blended with mono ethylene glycol(MEG) of 5${\sim}$15wt% showed smaller particle size and more stable particle size distribution than without MEG. Finally, this microemulsion showed more excellent values of gloss degree, the water resistant gloss degree and contact angle, than two kinds of commercial polishing wax for automobile.

Elemental analysis of rice using laser-ablation sampling: Determination of rice-polishing degree

  • Yonghoon Lee
    • Analytical Science and Technology
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    • v.37 no.1
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    • pp.12-24
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    • 2024
  • In this study, laser-induced breakdown spectroscopy (LIBS) was used to estimate the degree of rice polishing. As-threshed rice seeds were dehusked and polished for different times, and the resulting grains were analyzed using LIBS. Various atomic, ionic, and molecular emissions were identified in the LIBS spectra. Their correlation with the amount of polished-off matter was investigated. Na I and Rb I emission line intensities showed linear sensitivity in the widest range of polished-off-matter amount. Thus, univariate models based on those lines were developed to predict the weight percent of polished-off matter and showed 3-5 % accuracy performances. Partial least squares-regression (PLS-R) was also applied to develop a multivariate model using Si I, Mg I, Ca I, Na I, K I, and Rb I emission lines. It outperformed the univariate models in prediction accuracy (2 %). Our results suggest that LIBS can be a reliable tool for authenticating the degree of rice polishing, which is closed related to nutrition, shelf life, appearance, and commercial value of rice products.

THE AMOUT OF LOSS AND THE DEGREE OF SURFACE SMOOTHNESS OF GOLD ALLOY BY GOLD ALLOY POLISHING RUBBER POINT MATERIALS (금합금 연마재 종류에 따른 금합금 소실량과 연마 정도)

  • Kim, Myoung-Hwa;Yim, Soon-Ho;Chung, Moon-Kyu
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.2
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    • pp.277-295
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    • 1997
  • After clinical adjustment of dental casting restoration, re-polishing procedure is recommanded because the smooth gold sureface is lost. But there is the possibility to get more loose contact than that intended by loss of gold alloy according to the kinds of polishing materials and polishing time. Therefore in this study I polished type II gold alloy with 390gm force, 20,000rpm speed, and 8 kinds of gold alloy polishing materials, fabricated by 4 companies and then measured the amount of loss of gold alloy with Surfcorder SEF-30D and observed alloy surfaces polished by 3 brown rubber points with SEM. The amount of loss of gold alloys polished with 8 kinds of polishing materials and the degree of smoothness of gold alloys according to polishing time and polishing materials were compared. The following results were obtained : 1. When the amount of loss of gold alloys polished with 3 kinds of brown rubber point was compared, Alphalex brown point had the most amount of alloy loss, followed in decreasing order by Shofu brown point and Eveflex brown point. There was statistically significant difference in the amount of alloy loss according to polishing materials. 2. When the amount of loss of gold alloys polished with 5 kinds of green rubber point was compared, Shofu green point had the most amount of alloy loss, followed in decreasing order by Alphaflex green point, Dedeco green clasp polisher, and Eveflex green point. There was statistically significant difference in the amount of alloy loss according to polishing materials except Alphaflex green point and Dedeco green clasp polisher. 3. When the amount of loss of gold alloys polished with all kinds of rubber point was compared, there was no significant difference in Eveflex brown point, Alphaflex green point, and Dedeco green clasp polisher. 4. When average amount of alloy loss per 1 revolution by polishing materials was compared, Alphalex brown point had the greatest value as $0.329{\mu}m$ and Shofu supergreen point had the lowest value as $0.022{\mu}m$. 5. When the degree of sureface smoothness of gold alloy polished with 3 kinds of brown rubber point was compared, In Alphalex brown point surface roughness was completely lost after 20 seconds polishing time, in Shofu brown point 30 seconds, in Eveflex brown point 40 seconds. But in every gold alloys fine scratch formed by rubber points was observed. Based on the results of this study, as rubber polishing materials used in polishing of dental casting restoration after clinical adjustment influenced on the tightness of occlusal or proximal contact, we should make dental casting restoration with minimum error through careful laboratory procedure and form very smooth surface of restoration with tripoli and rouge after use of silicone polishing materials.

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Effects of Forced Self Driving Function in Silicon Wafer Polishing Head on the Planarization of Polished Wafer Surfaces (실리콘 웨이퍼 연마헤드의 강제구동 방식이 웨이퍼 연마 평탄도에 미치는 영향 연구)

  • Kim, Kyoungjin;Park, Joong-Youn
    • Journal of the Semiconductor & Display Technology
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    • v.13 no.1
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    • pp.13-17
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    • 2014
  • Since the semiconductor manufacturing requires the silicon wafers with extraordinary degree of surface flatness, the surface polishing of wafers from ingot cutting is an important process for deciding surface quality of wafers. The present study introduces the development of wafer polishing equipment and, especially, the wafer polishing head that employs the forced self-driving of installed silicon wafer as well as the wax wafer mounting technique. A series of wafer polishing tests have been carried out to investigate the effects of self-driving function in wafer polishing head. The test results for wafer planarization showed that the LLS counts and SBIR of polished wafer surfaces were generally improved by adopting the self-driven polishing head in wafer polishing stations.

A Study on Magnetic Abrasive using Sludge

  • Kim, Hee-Nam
    • Journal of the Speleological Society of Korea
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    • no.82
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    • pp.8-12
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    • 2007
  • In this paper, we have investigated the characteristics of the magnetic abrasive using sludge on polishing of internal finishing of seamless stainless steel tube applying magnetic abrasive polishing. Either green carborundum(GC) grain was used to resin sludge at a low temperature, and the sludge of magnetic abrasive powder was synthesized and crushed into 200 meshes. Surface roughness was measured before and after polishing, and more than 38% of improvement of surface roughness was achieved when grain was used under a specific condition. Even though some degree of surface roughness due to deeper scratches still exist, but the result showed a prospective magnetic abrasive polishing using sludge with green carborundum grains.

Tocotrienol and Tocopherol Contents of Rice Bran by Milling Recovery (도정율에 따른 미강의 Tocotrienol과 Tocopherol 함량)

  • Park Kyeong-Yeol;Kang Chang-Sung;Cho Young-Cheol;Lee Yong-Sun;Lee Young-Hyun;Lee Young-Sang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.49 no.6
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    • pp.468-471
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    • 2004
  • Tocotrienol $(T_3)$ and tocopherol (T) are well-known antioxidant vitamin E isomers that are enriched in rice bran, most of which is removed during polishing process. To verify the polishing-dependent fractional content of tocotrienol and tocopherol, harvested brown rice of 4 cultivars were polished by 4.0, 6.4, 8.0, 9.6, and $12\%$ (w/w) and resultant bran powder and rice were used for $T_3$ and T analysis. Polishing degree affected bran $T_3$ content in that bran polished by $6.4\%$ exhibited highest $T_3$ content compared to other polishing degrees except in cv. Chucheongbyeo which showed similar $T_3$ content from 4.0 to $8.0\%$ polishing. In case of tocopherol, bran polished by $8.0\%$ exhibited highest T content in all tested cultivars. In general, $T_3$ distributed in higher quantity in exterior i.e., in less polished bran, while T showed relatively less decrease with enhanced polishing degree. Consequently, total vitamin E content in bran as calculated by the summation of $T_3$ and T became less dependent on polishing degree in that bran polished between 6.4 to $9.6\%$ exhibited no statistical differences. The rice of cv. Chuchongbyeo, remained after polishing, exhibited similar vitamin E content up to $6.4\%$ polishing, above which significant vit E loss could be observed. These results suggest that polishing less than $6.4\%$ is desirable to minimize the loss of tocotrienols and tocopherols during polishing.

A STUDY ON THE COLOUR PENETRATION OF KOREAN FOODS SUBSTANCE TO CAVITY MARGIN OF COMPOSITE RESIN RESTORATION (복합레진 충전술식에 따른 조미료(장류)의 와동변연 색소 침투에 관한 연구)

  • Ahn, Sang-Hun
    • Restorative Dentistry and Endodontics
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    • v.8 no.1
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    • pp.69-76
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    • 1982
  • The purpose of this study was to evaluate the color penetration of cavity margin with composite resin restorations in some Korean foods substance-soy sauce and hot bean paste. Fifty specimans which were extracted caries free third molar of young adults recently. All of the prepared 100 cavities were filled with two kinds of composite resin (Hipol$^{(R)}$and Restodent$^{(R)}$). The experimental specimans were divided into five groups by the following procedures. Group I : Filling of composite resin and polishing. Group II : Filling, polishing, etching of cavity and sealing. Group III : Etching, sealing, filling and polishing. Group IV : Etching, sealing, filling, polishing, and repeated of etching of cavity margin and sealing. Group V : Etching, sealing, filling, polishing, and sealing again without etching. Before examination, the restorated teeth were subjected to thermal cycling ($4^{\circ}C$ and $60^{\circ}C$). All the specimens were immersed in soy and 30% hot bean paste solution under $37^{\circ}C$ incubator during six weeks. Then, the specimens were sectioned bucco-lingually through the center of two restorations with diamond disk and examined under a. metallographic microscope. (Union 6617 U.S.A.) Thereafter, the degree of color penetration was calculated and analyzed. The obtained results were as follows: 1. The color penetration was the lowest in the procedure of Group III which was acid etching, sealing, composite resing filling, and polishing. 2. The color penetration occured in soy and hot bean paste, but the degree of penetration was not so significant statistically between them. 3. The degree of color penetration was not so significant statistically between Hipol$^{(R)}$ and Restondent$^{(R)}$.

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Improvement of Transmittance and Surface Integrity of Glass Mold for light-hardening polymer Using MR Polishing (HR polishing에 의한 광경화성수지 성형용 글래스 몰드의 투과율 및 표면품위 향상)

  • Lee, J.W.;Kim, D.W.;Cho, M.W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.78-83
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    • 2009
  • In general, Light-hardening polymer was used UV nanoimprint technology. A light-hardening polymer was had the problem of poor hardness, durability. In order to overcome the problem of polymer, inter change optical glass. However glass is very manufacture and a lowering of standars transmittance. In order to glass recover was necessary polishing process. The process is magnetorheological fluids polishing. MR polishing has been developed as a new precision finishing technique to obtain a fine surface. Hence, Magnetorheological fluids has been used for micro polishing to get micro parts. This polishing process guarantees high polishing quality by controlling the fluid density electrically. The applied material in experiments is fused silica glass. Fused silica glass is widely used in the optical field because of high degree of purity. For MR polishing experiments, MR fluid was composed with DI-water, carbonyl iron and nano slurry ceria. The wheel speed and electric current were chosen as the variables for analyzing the characteristics of MR polishing process. Outstanding surface roughness of Ra=1.58nm was obtained on the fused silica glass specimen. And originally glass transmittance was recover on the fused silica glass.

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