• Preventive Nutrition and Food Science
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• 제3권4호
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• pp.382-386
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• 1998

A soluble dietary fiber, $\beta$-glucan, contained in oat and barley has nutritional benefits such as hypocholesterolemic effects and influences blood glucose regulation. The contents of $\beta$-glucan in both cereals range from 3 to 7% with the exception of a certain barley genotype which contains up to 16% $\beta$-glucan. $\beta$-Glucan is distributed mainly in the cell walls of endosperm and the distal (bran) portion of kernel. Various procedures have been developed for increasing the extraction yield of $\beta$-glucan. Oat gum prepared with weak alkali extractionand alcohol proecipitation following protein removal usually contains 80% $\beta$-glucan.The most commonly used method for $\beta$-glucan quantitiation is an enzymatic procedure combining lichenase plus $\beta$-glucosidase followed by measuring the amount of glucos released by glucose oxidase-peroxidase treatment. The increase in foam-and emulsion-stabilizing capacity of $\beta$-glucan is due to the increase in viscosity of the aqueous phase. Therefore, $\beta$-glucan shows great potentials as a thickener and a stabilizer.

• 한국분말재료학회지
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• 제29권4호
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• pp.325-331
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• 2022

Beta-titanium alloys are used in many industries due to their increased elongation resulting from their BCC structure and low modulus of elasticity. However, there are many limitations to their use due to the high cost of beta-stabilizer elements. In this study, biocompatible Ti-Mo-Fe beta titanium alloys are designed by replacing costly beta-stabilizer elements (e.g., Nb, Zr, or Ta) with inexpensive Mo and Fe elements. Additionally, Ti-Mo-Fe alloys designed with different Fe contents are fabricated using powder metallurgy. Fe is a strong, biocompatible beta-stabilizer element and a low-cost alloying element. The mechanical properties of the Ti-Mo-Fe metastable beta titanium alloys are analyzed in relation to the microstructural changes. When the Fe content increases, the tensile strength and elongation decrease due to brittle fracture despite a decreasing pore fraction. It is confirmed that the hardness and tensile strength of Ti-5Mo-2Fe P/M improve to more than 360 Hv and 900 MPa, respectively.

• 한국세라믹학회지
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• 제34권9호
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• pp.957-962
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• 1997

Dicalcium silicate has many polymorphs according to temperature. $\beta$-dicalcium silicate which exists in cement is stabilized by minor components drived from raw materials regardless of temperature, such as high temperature and room temperature. K2O, SO3 and B2O3 are effective stabilizers for $\beta$-dicalcium silicate at room temperature. B2O3 was the most effective stabilizer. Transformation from $\beta$ to ${\gamma}$ phase causes dicalcium silicate to change volume, resulting in dusting phenomenon. When B2O3 was used the phase transformation is the least than any other stabilizers. In addition, the starting temperature of quenching influences phases transformation : low temperature of quenching presented much phase transformation and decreased size of parameter of $\beta$-dicalcium silicate.

• 대한수학회보
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• 제44권4호
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• pp.817-823
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• 2007

In this paper, we develop a simple method for computing the stabilizer subgroup of a subgroup of $$D(g)={{\alpha}{\in}\mathbb{F}_q|there\;is\;a\;{\beta}{\in}{\mathbb{F}}^x_q\;such\;that\;{\beta}^n=g(\alpha)}$$ in $PSL_2(\mathbb{F}_q)$, where q is a large odd prime power, n is a positive integer dividing q-1, and $g(x){\in}\mathbb{F}_q[x]$. As an application, we construct new infinite families of 3-designs (cf. Examples 3.4 and 3.5).

• 열처리공학회지
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• 제29권5호
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• pp.227-233
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• 2016

Phase transformation phenomenon at high temperature was investigated by using designed TiAl-Nb alloys with addition of the ${\beta}$ stabilizer. Examination of dendritic morphologies in arc-melted button ingot could reveal the crystallography of the primary solidification phase. It was found that the addition of ${\beta}$ stabilizer(Nb) shifted the high temperature region of the binary Ti-Al phase diagram to the high Al composition side so that ${\beta}$ phase forms as a primary crystal even at higher Al composition compared with the binary Ti-Al system. The ${\beta}$ was found to be the primary solidification phase for alloys with Al content less than about 52 at.%. The composition of ${\beta}$ solidification in Ti-Al-Nb ternary system could be determined from the partial liquidus projection which was constructed by observing the microstructure of arc-melted buttons. The Ti-46Al-(6, 8)Nb composition was selected for ${\beta}$ solidification and the directional solidification was performed by a floating zone-type DS apparatus at the growth rate 30 mm/hr respectively.

• 한국균학회지
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• 제26권2호통권85호
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• pp.275-280
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• 1998

장수버섯(Fomitella fraxinea)의 원형질체 분리와 재생에 영향을 미치는 요인을 조사하고자 본 연구를 수행하였다. 세포벽 분해 효소 종류별 원형질체 분리 시험을 수행한 결과 장수버섯 ASI 17001은 Novozym 234+Cellulase onozuka R-10+${\beta}-Glucuronidase$를 혼합하여 처리하였을 때 원형질체 분리율이 $8.9{\times}10^4/ml$로 가장 높았다. 원형질체 분리시 사용하는 삼투압 조절제로는 0.6 M sucrose가 가장 양호하였으며, 처리시간은 3시간이 가장 양호하였다. 원형질체 재생율은 0.6 M sorbitol에서 0.02%로 다른 조절제에 비하여 양호한 결과를 나타내었으나 KCl는 전혀 재생이 되지 않았다.

• 공업화학
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• 제23권6호
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• pp.534-538
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• 2012

$ Na^+$-beta-alumina 고체전해질을 고상반응법을 통해 합성하였으며, 두 종류의 안정화제 $Li_2O$와 MgO가 상 형성 및 소결밀도에 미치는 영향을 비교 분석하였다. 합성온도에 따른 ${\beta}/{\beta}^{{\prime}{\prime}}$-alumina 상 분율 분석을 위해, [$Na_2O$] : [$Al_2O_3$] = 1 : 5의 고정된 몰 비에서 하소온도를 $1200{\sim}1500^{\circ}C$로 변화하여, 각각 2 h동안 하소하였다. $Li_2O$를 안정화제로 사용한 경우에는 $1500^{\circ}C$에서 2차 상 전이가 발생해 ${\beta}^{{\prime}{\prime}}$-alumina 상 분율의 증가가 나타났지만, MgO를 첨가했을 때는 하소온도에 관계없이 상 분율이 유지되었다. 또한 disc 형태의 $Na^+$-beta-alumina 샘플을 $1550{\sim}1650^{\circ}C$의 온도에서 각각 30 min 소결한 후 상대 소결밀도, 상 변화 및 미세구조를 분석하였다. $Li_2O$를 안정화제로 사용하였을 때, 소결온도 $1600^{\circ}C$에서 ${\beta}^{{\prime}{\prime}}$-상 분율과 상대밀도가 각각 94.7%와 98%로 가장 높은 값을 나타냈으며, MgO를 안정화제로 사용하였을 경우, 소결온도의 증가에 따라 상대밀도가 크게 증가하는 결과를 보였다.

• 한국균학회지
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• 제14권2호
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• pp.141-148
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• 1986

버섯의 품종개발(品種開發)과 유전연구(遺傳硏究)를 위해서 느타리 균(菌)의 일종(一種)인 P.cornucopiae 노랑 느타리의 원형질체(原形質體) 분리(分離)에 적합한 제조건(諸條件)을 조사하였다. 원형질체(原形質體) 분리(分離)의 최적(最適) 조건(條件)으로 Novozym 234농도(濃度)는 $5\;mg{\cdot}ml^{-1}$이었고 Novozym $234+{\beta}-D-glucanase\;+{\beta}-glucuronidase\;mixture$에서 원형질체수(原形質體數)는 $10.55{\times}10^6\;ml^{-1}$으로 가장 높았으며, 삼투압(渗透壓) 조절제(調節劑)와 농도(濃度)는 0.6 M sucrose에서 효과적(效果的)이었고 혼합효소액(混合酵素液)과의 반응(反應) 90분일때 원형질체(原形質體) 분리량(分離量)은 $2.2{\times}10^7\;ml^{-1}$으로 높았다. 완충용액(緩衝溶液)과 pH는 0.6 M sucrose+Na-maleate buffer (pH 5.0), 0.6 M sucrose+phosphate buffer(pH 6.2)에서 원형질체(原形質體) 분리량(分離量)이 좋았으며 대체로 phosphate buffer가 효과적인 것으로 나타났고 pH를 조절하지 않은 0.6M sucrose 삼투압 조절제(調節劑)가 원형질체(原形質體) 분리(分離)에 가장 알맞았다. 그리고 배양(培養) 일수(日數) 및 균사체량(菌絲體量)을 보면 cellophane MCM에서 4일 배양(培養)한 균사체(菌絲體) 6colonies와 혼합효소(混合酵素) 4 ml과 혼합하여 $28^{\circ}C$에서 90 분간 흔들었을 때 원형질체(原形質體)가 가장 많이 분리되었다.

• Bulletin of the Korean Chemical Society
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• 제23권11호
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• pp.1548-1552
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• 2002

$(-)-\beta-Narcotine$ (6), a phthalideisoquinoline alkaloid, was synthesized conveniently by the direct condensation of cotarnine (1) and iodomeconine (2) prepared by aromatic iodination using thallium trifluoroacetate/KI and by the successive reduction of resulting $iodo-{\beta}-narcotine$ (5) with aluminum amalgam. Its structure including a stereochemistry was confirmed by instrumental analyses. This synthetic alkaloid was degraded with ethyl chloroformate at room temperature to afford the chloro-carbamate 6b as a crystalline intermediate, which was unexpectedly converted into the carbinol 8 by exchange of Cl with OH of water contained in the solvents and the ethoxy-carbamate 9, probably because of ethanol added to chloroform as a solvent stabilizer during the purification by column chromatography.

• 대한치과기공학회지
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• 제27권1호
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• pp.9-17
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• 2005

The use of titanium alloys as biomaterials is increasing due to their superior biocompatibility and enhanced corrosion resistance compared to conventional stainless steels and cobalt-based alloys. Ti-6Al-4V ($\alpha+\beta$type) alloy instead of pure titanium ($\alpha$type) is being widely used as biomaterials has some characteristics such as high fatigue strength, tensile strength and corrosion resistance. But it has been reported recently that the vanadium element expresses cytotoxicity and the aluminium element is related with dementia of Alzheimer type and neurotoxicity. In order to overcome their detrimental effects, $\beta$-phase stabilizer Nb was chosen in the present study. This paper was described the influence of phase changes of Ti-Nb alloys on mechanical properties. Ti-3wt.%Nb($\alpha$type),Ti-20wt.%Nb($\alpha+\beta$type) and Ti-40wt.%Nb($\beta$type) alloys were melted by vacuum arc furnace. The specimens were homogenized at 1050$^{\circ}C$ for 24hr and were then hot rolled to 50% reduction. Each alloys were solution heat treated at $\beta$ zone and $\alpha+\beta$ zone after homogenization and then were aged. The mechanical properties of Ti alloys were analysed by hardness test, tensile test, elongation test and SEM test. The results can be summarized as follows: 1) The higher hardness value of $\alpha+\beta$type alloy was obtained compared to the, $\alpha,\beta$type alloys. 2) The aged treated showed better hardness compared to the solution heat treated, homogenized. 3) In the case of solution and aging treatment at $\beta$region, the $\alpha+\beta$type alloy showed the most highest tensile strength and $\beta$type alloy showed the best elongation.