• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.886-890
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• 2014

The properties of magnetic material of Nd-Fe-B are highly affected by various factors such as particle size, magnetic anisotropy, phase purity and crystal structure. Incorporation of excess neodymium was carried out in various percentages so that it will adjust the proportion of neodymium in the host crystal after reduction treatment and finally help to improve magnetic property of a material. The interdiffusion of Nd-Fe and boron was studied for various compositions and their effect on magnetic property was understood with theoretical concepts. The factors such as amount of hard and soft phase in the reduction treated product is also responsible for the possible exchange coupling between hard and soft phase magnets for better magnetic properties.

• 한국세라믹학회지
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• 제30권6호
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• pp.492-498
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• 1993

The pretreatment condition for uniform distribution of SiC whisker in A2O3-SiCw composites has been determined and the mechanical properties of the composites with various whisker contents have been measured. Good dispersion of the whisker can be obtained in a solution of pH=10.45 by ball milling and ultrasonic treatment. The relative density of hot pressed composites decreases with the whisker content up to 40vol%, but is found to be satisfactory, over 98% for all samples. The mechanical property of the composites is sensitive to the whisker dispersion. Uniform distributjion of the whisker is critical in order to guarantee good mechanical property.The samples containing 20~30vol% whisker show the best mechanical property within the studied range.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1487-1489
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• 2001

The tantalum oxide($Ta_2O_5$) is an important material for present thin-film capacitor application owing to its high dielectric constant and thermal stability. We report dielectric property of Si(p type)/Pt/$Ta_2O_5$/Ag based MIM structure obtained by RF sputtering and annealed in vacuum environment. We have measured and researched the characteristics of C-F, C-V and EPMA. And we describe parameter dependence on sputtered condition and annealed temperature with dielectric property.

• 대한수학회지
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• 제57권2호
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• pp.283-312
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• 2020

A sufficient condition for an Artinian complete intersection quotient S = 𝕜[x, y]/(x^m, yⁿ), where 𝕜 is an algebraically closed field of a prime characteristic, to have the strong Lefschetz property (SLP) was proved by S. B. Glasby, C. E. Praezer, and B. Xia in [3]. In contrast, we find a necessary and sufficient condition on m, n satisfying 3 ≤ m ≤ n and p > 2m-3 for S to fail to have the SLP. Moreover we find the Jordan types for S failing to have SLP for m ≤ n and m = 3, 4.

• Food Science and Biotechnology
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• 제15권1호
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• pp.133-137
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• 2006

Wheat gluten-chitosan composite film (WGCCF) can prevent moisture migration and enhance the antimicrobial properties of gluten in intermediate-moisture foods like sandwiches. To mimic the structure of actual sandwich-type products we developed multi-layer food models, where moisture content and water activity differ. Water activity gradients direct moisture migration and therefore determine product characteristics and product stability. A 10% wheat gluten film-forming solution was mixed with chitosan film-forming solution (0-3%, w/w) and evaporated to generate WGCCF. Addition of 3% chitosan enhanced the mechanical properties of the film composite, lowered its water vapor permeability, and improved its ability to protect against both, Streptococcus faecalis and Escherichia coli, in a 24 hr sandwich test (reduction of 1.3 and 2.7 log cycles, respectively, compared to controls). Best barrier and antimicrobial performance was found for 3% chitosan WGCCF at pH 5.1. Film of this type may find application as barrier film for intermediate-moisture foods.

• 한국의류학회지
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• 제10권3호
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• pp.71-81
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• 1986

In order to control the formaldehyde release from D.P. finished fabric, cotton fabric was padded in DMDHEU resin bath containing either $Zn(NO_3)_2$ or $MgCl_2$ catalyst and a form-aldehyde scavenger like Glycerol, Sorbitol, Formamide, Polyvinyl alcohol (PVA, n= 2000) or diols, then dried and cured. The results are as follows : 1. When Lewis acid catalyst like $Zn(NO_3)_2$ or $MgCl_2$ was added in pad bath, the fabric finished with $Zn(NO_3)_2$ catalyst released the lower formaldehyde than with $MgCl_2$. 2. When the effect of pad bath pH was examined with varying the kinds of catalyst and the scavenger, it was found that the pad bath pH influenced on the amount of formaldehyde release and the optimum pad bath pH is at 4.3. Especially, in case of finishing at pad bath pH 4.3 with adding Formamide, the amount of formaldehyde release was decreased by about $45\~$35\%$ with $Zn(NO_3)_2$, while by about $20\~$45\%$ with $MgCl_2$ catalyst. In case of varying the concentration of a scavenger (Formamide), $1\%$ concentration of a scavenger was found to be the optimum level ana the higher the curing temperature up to $180^{\circ}C$, the lesser the amount of formaldehyde release were observed. 3. When the diol was used as scavenger, the amount of formaldehyde release was decreased by about $40\~$50\%$, but the longer the intramolecular length between OH groups, the lessor the amount of decrease of formaldehyde release were observed. 4. When the mixture of scavengers (Formamide and Glycerol) was added in the pad bath, .synergistic effect on formaldehyde release between the two scavengers wasn't observed. 5. The tensile strength of the resin finished fabric was reduced with increasing the pad lath pH and was influenced by the kind of scavengers, and the tensile strength was severely reduced when scavengers, especially Formamide, was added. The wrinkle recovery property is generally improved by resin finish on cotton fabric. When Formamide was added, the wrinkle recovery property is slightly decreased compared with that of the fabrics resin finished without a scavenger, and when polyol was added, the wrinkle recovery property showed almost no change.

• 한국식품영양과학회지
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• 제39권3호
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• pp.406-413
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• 2010

황기 추출액의 수율 및 생리적 기능성을 향상시키기 위하여 황기에 효소를 첨가하여 시간별로 가수분해 시킨 후 가열처리하고 여과시킨 추출액에 대하여 이화학적, 항산화 활성 및 관능적 평가를 측정하였다. 효소처리 황기 추출액의 $^{\circ}Brix$의 변화는 대조군보다 ClariSEB 및 Fungamyl 처리 시 증가하였으며 pH 및 산도는 효소처리에 의하여 약간 낮은 pH와 높은 산도를 보였다. 색상변화에서는 ClariSEB 및 Fungamyl 처리 시 lightness가 증가하였으며 redness와 yellowness는 감소하였다. 환원당, flavonoid 및 polyphenol 화합물 함량은 효소처리에 의하여 함량이 증가하였으나 ascorbic acid는 대조군과 유사하였다. 황기 추출액의 지질과 산화 억제능은 효소처리 시 억제능이 약간 증가하는 것으로 나타났고 DPPH 항산화 활성, ABTS 항산화 활성 및 금속이 온 제거능에서는 ClariSEB 및 Fungamyl 처리 시 증가하였으나 환원력은 대조군과 유사하였다. 또한 황기 추출액에 대한 관능검사 결과 전반적으로 효소처리를 하지 않은 대조군에 비하여 효소처리 시 기호도 면에서 우수한 것으로 나타났다.

• 호남수학학술지
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• 제40권4호
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• pp.621-659
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• 2018

Let us consider that ${\mathbb{K}}$ be a complete ultrametric algebraically closed field and A (${\mathbb{K}}$) be the ${\mathbb{K}}$-algebra of entire functions on ${\mathbb{K}}$. In this paper we introduce the notions of (p, q)-th relative order and (p, q)-th relative type of entire functions on ${\mathbb{K}}$ where p and q are any two positive integers and then study some basic properties of p-adic entire functions on the basis of their (p, q)-th relative order and (p, q)-th relative type.

• 대한수학회보
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• 제33권3호
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• pp.445-453
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• 1996

A closed subspace J of a Banach space X is called an M-ideal in X if the annihilator $J^\perp$ of J is an L-summand of $X^*$. That is, there exists a closed subspace J' of $X^*$ such that $X^* = J^\perp \oplus J'$ and $\left\$\mid$ p + q \right\$\mid$ = \left\$\mid$ p \right\$\mid$ + \left\$\mid$ q \right\$\mid$$ wherever $p \in J^\perp and q \in J'$.

• 대한수학회지
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• 제39권1호
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• pp.61-75
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• 2002

Under the cancellation property and the Lipschitz condition on kernels, we prove that the Marcinkiewicz integrals defined on a homogeneous group H are bounded from $H^1$(H) to $L^1$(H), from $L_{c}$ $^{\infty}$(H) to BMO (H), and from $L^{p}$ (H) to $L^{p}$ (H) for 1 < p < $\infty$ assuming the $L^{q}$ -boundedness for some q > 1.for some q > 1.