• 제목/요약/키워드: Preparation Temperature

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Comparison of optimal temperature and time conditions for highest a-glucosidase inhibitory activity from various of Korea mulberry teas

  • Ju, Wan-Taek;Kim, Hyun-Bok;Sung, Gyoo-Byung;Kim, Yong-Soon
    • International Journal of Industrial Entomology and Biomaterials
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    • v.33 no.1
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    • pp.31-35
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    • 2016
  • The influence of commonly used steeping times and temperatures about mulberry tea on a-glucosidase inhibitory activity were studied. The effects of product and preparation variables on the in-cup chemical composition of mulberry tea extracts is of interest because the appearance and taste characteristics and the possible health effects of a tea liquor arise from the chemical components extracted from the leaf during mulberry tea preparation. A comprehensive study was therefore undertaken to determine the contributions of product and provide a basic data for development of high quality mulberry tea products against diabetes. Specific eight mulberry tea were collected from each region of Korea (A-I) and when it was extracted on 85℃ for 2min, a-glucosidase activity was best for 98-102%. According to various temperature and time extraction methods, this study was carried out to optimize teamaking conditions for maximal DNJ extraction from Korean mulberry tea and and it would be of particular interest for people who drink mulberry tea to control blood glucose levels.

Standardization of Surface Replication Procedures for Life Assessment of High Temperature Facilities (고온설비 수명평가를 위한 표면복제 절차의 표준화)

  • Park, Jong-Seo;Lee, Hae-Mu;Baek, Un-Bong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2381-2386
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    • 2000
  • Surface replication is playing an important role in the assessment of creep damage and remaining life of high temperature components. As the replication procedures, however, have not been standardized in domestic industry, its standardization is proposed in this study. For this purpose, the 2.25Cr-IMo steel was heat treated(5 min at 1,300 0C and oil quenched) to produce a simulated HAZ microstructure, and crept in air at 575 0C and under 120 MPa to produce artificial cavities. Then, the effect of surface preparation procedures on the quality of replicas was investigated using this sample. As a result, it was demonstrated that the presence of cavities may be observed readily or missed depending on the surface preparation procedures followed. Therefore it is essential to repeat three polishing/etching cycles at least in order to reveal cavitation damage accurately, even though it may be tedious or time-consuming.

Experimental study on the standardization of the Hot and the Cold Natures (열약과 한약의 사기론적 평가기준에 대한 실험적 연구)

  • Lee, Han-Goo;Nam, Bong-Hyun;Lee, Mi-Young;Kim, Chung-Sook
    • Korean Journal of Oriental Medicine
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    • v.2 no.1
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    • pp.506-513
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    • 1996
  • The odor theory(氣味論) has been defined as the Nature(氣) and the Taste(味) of traditional herbal medicine to find the logic in treatment of various diseases by them. There is a strong possibility these Natures of the drug can be categorized according to yin(陰) and yang(陽). To understand the Hot and the Cold Natures of traditional herbal drugs in scientific approaches, changes in skin, rectal temperature of rats have been measured at 0, 30, 60, 90 min after a 5, 10, 20g/Kg oral administration each of Coptidis Rizoma(Ranunculaceae, Coptis chinesis, $F_{RANCH}$), Aconiti Lateralis Preparata Radix(Ranunculaceae, Aconitum carmichaeli $D_{EBX}$). From this study, we obtained as follows. 1. We can categorize the four Natures of drug according to yin(陰) - Cool and Cold Natures and yang(陽) - Warm and Hot Natures. 2. The relation between the four Natures of drug and the changes of body temperature can be studied as the considertion of the dosage and the preparation of crude medicines. 3. Herbs containing toxicant should be studied carefully without the side effects.

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Preparation of Nano-sized Titanium Oxide Powder Using Natural Polymer Matrix (천연고분자 매트릭스를 사용한 산화티탄 나노입자의 합성)

  • Kim, Soo-Jong;Han, Cheong-Hwa;Shim, Jae-Ho
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.489-494
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    • 2013
  • Nano-sized titanium oxide powders were synthesized by a polymer matrix technique using pulp and Titanium tetraisopropoxide (TTIP) as starting materials. The synthesized powders were characterized by XRD and FE-SEM. The particle size of the powders was controlled by preparation conditions, such as heat treatment temperature and time. After investigating various drying and heat treatment conditions, 50-100 nm sized homogeneous titanium oxide particles were obtained by treating at $600^{\circ}C$ for 1 h. The crystallization and rapid growth of particles was accelerated by increasing heat treatment temperature and time. Anatase phase generated below $600^{\circ}C$ transformed to the rutile phase with increasing heat treatment temperature. Moreover, above $800^{\circ}C$, heat treatment time had a very large influence on particle growth, and changing the heating condition also had a large influence on crystal growth.

Biomolecular Strategies for Preparation of High Quality Surimi-Based Products

  • Nakamura Soichiro;Ogawa Masahiro
    • Preventive Nutrition and Food Science
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    • v.10 no.2
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    • pp.191-197
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    • 2005
  • There exist two interesting phenomena in making seafood products from surimi. When salted surimi is kept at a constant low temperature $(4\~40^{\circ}C)$, its rheological properties change from sol to gel, which is called 'setting'. Seafood processors can exploit changes that occur during setting in preparation of surimibased products, because heating at high temperatures, after the pre-heating during the setting process, enhances the gel-strength of salted surimi. Contrarily, when salted surimi or low-temperature set gel is heated at moderate temperatures $(50\~70^{\circ}C)$, a deterioration of gel is observed. The phenomenon is termed 'modori'. In the modori temperature range, heat-stable cysteine proteinases such as cathepsin B, H, Land L-Iike hydrolyze the myosins responsible for gel-formation, resulting in gel weakening modori. This article reviews molecular events occurring during gel setting that improve the quality of surimi-based products, and inhibition of modori by applying proteinase inhibitors. Application of recombinant protein technology to surimi-based products is introduced and its prospects for practical use are discussed.

Preparation of Y3Al5O12 Nanocrystals by a Glycol Route

  • Bartwal, Kunwar Singh;Kar, Sujan;Kaithwas, Nanda;Deshmukh, Monica;Dave, Mangla;Ryu, Ho-Jin
    • Journal of the Korean Ceramic Society
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    • v.44 no.5 s.300
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    • pp.151-154
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    • 2007
  • Yttrium aluminum garnet, $Y_3Al_5O_{12}$ (YAG) is an extensively used solid-state laser host material. YAG nanocrystals were synthesized using low-temperature glycol method, a modified sol-gel method performed at low temperature that consists of a mixture of salts that are mostly nitrates in an aqueous media. Single-phase nanocrystalline YAG was obtained at $850^{\circ}C$, which is a much lower temperature than with other techniques such as a wet-chemical technique. The structural characterization is done by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. A crystallite size range of 20-50 nm was observed for the materials prepared at $850-950^{\circ}C$.

Preparation of SnO$_2$ Thin Films by Chemical Vapor Deposition Using Hydrolysis of SnCla$_4$ and Gas-sensing Characterisics of the Film -Effect of Deposition Variables on the Deposition Behavior and the Electrical Resistivity of SnO$_2$ Thin Film- (SnCl$_4$가수분해 반응의 화학증착법에 의한 SnO$_2$박막의 제조 및 가스센서 특징(I) Preparation of SnO2 Thin Films by chemical Vapor Deposition Using Hydrolysis of SnCl4 and gas-sensing characteristics of the Film)

  • 김용일;김광호;박희찬
    • Journal of Surface Science and Engineering
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    • v.23 no.2
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    • pp.18-23
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    • 1990
  • Thin films of tin oxide were prepared by chemical vapor deposition (C.V>D) using the hydrolysis reaction of SnCl4, Deposition rate increased with the increase of temperature up to $500^{\circ}C$and then decreased at $700^{\circ}C$, Deposition rate with SnCl4 partial pressure showed RidealEley behavir. It was found that SnO2 thin film deposited at the temperature above $400^{\circ}C$ had(110) and (301) plane preferred orientation with crystallinity of rutite structure. Electrical resisvity of SnO2 thin film decreased with increase increase of deposition temperature and showed minimum value of 10-3 ohm at $500^{\circ}C$and than largely increased increased with further increase of deposition temperture.

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A Study on the Methodology of Chromosome Preparation from Blood Culture (혈액세포를 이용한 염색체 분리 분석에 관한 방법적 고찰)

  • Sohn, S.H.;Chung, K.M.
    • Clinical and Experimental Reproductive Medicine
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    • v.21 no.2
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    • pp.207-214
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    • 1994
  • This study was carried out to develop the methodology of chromosome preparation from blood cultures in mammals which included human, mouse, cattle and pig. For karyotyping, 0.5-5.0ml of peripheral blood were collected and cultured. The satisfactory results were obtained from macroculture and microculture in all species. In culture, the patterns of cell growth were no difference among media except serum concentration and mitogen supplement. The presence of mitogen and fetal bovine serum in medium significantly affected the mitotic index. The optimal culture condition was 37$^{\circ}C$ for 3 days. And the concentration of colcemid and reincubation time also affected the chromosome morphology. In harvest, chromosome patterns were mainly affected on hypotonic treatment which included treated time and temperature, dropwise of fixative solution, and drying after slide preparation.

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Role of Metal Catalyst and Substrate Site for the Growth of Carbon Nanomaterials

  • Manocha, L.M.;Valand, Jignesh;Manocha, S.
    • Carbon letters
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    • v.6 no.2
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    • pp.79-85
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    • 2005
  • The work reported in this paper relates to preparation and characterization of carbon nanomaterials by CVD method on different substrates by decomposition of certain hydrocarbons at 550-$800^{\circ}C$ using a horizontal quartz tube reactor. Monometallic and bimetallic catalyst system of iron and nickel were used for the preparation of different carbon nanomaterials. The influence of various parameters such as substrate/catalyst preparation parameters, the nature of substrate, catalyst concentration, reaction time and temperature on the growth, yield and alignment of carbon nanotubes has been studied. The characterization of carbon nanomaterials has been carried out using SEM, TEM and TGA. The carbon nanomaterials developed were vertically aligned on a large area of flat quartz substrate.

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Effect of pH and Reaction Temperature on Mechanical Properties of Hydroxyapatite for Dental prosthesis (치관보철용 Hydroxyapatite의 기계적 물성에 미치는 pH 및 반응온도의 영향)

  • Chung, In-Sung;Her, Ho-Young
    • Journal of Technologic Dentistry
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    • v.26 no.1
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    • pp.89-96
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    • 2004
  • Hydroxyapatite powder were synthesized by precipitation method, varying pH, and reaction temperature. The powders were heated at 1,200$^{\circ}{\cdots}$ and 1,300$^{\circ}{\cdots}$ for fabrication of dental prosthesis. The results are as follows: Synthesized powder showed the smallest particle in size, under the conditions of pH 11 and reaction temperature 37$^{\circ}{\cdots}$. The hydroxyapatite was partially converted to $\alpha,\;\beta$-TCP at 1,200$^{\circ}{\cdots}$ and 1,300$^{\circ}{\cdots}$. Mechanical strength of sample was affected by such powder preparation conditions as pH and reaction temperature and sintering temperature. The mechanical strength of sample prepared under the same conditions was increased with increasing pH, reaction temperature and sintering temperature.

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