• 한국식품영양과학회지
• /
• 제37권7호
• /
• pp.847-852
• /
• 2008

팽화홍삼분말이 B($\alpha$)P의 투여에 의한 간 독성이 유발된 마우스에서의 글루타치온 및 과산화지질 함량, 항산화 효소활성에 미치는 영향을 살펴보았다. B($\alpha$)P 투여에 의해 증가된 혈청 내 ALT와 AST의 활성이 팽화홍삼분말을 투여하면 감소하였다. 간 조직중의 SOD, catalase 그리고 GSH-Px의 활성도 B($\alpha$)P 투여로 유의적으로 증가되었다가, 팽화홍삼분말의 투여로 이들 활성이 유의적으로 감소하였고, 반면, 글루타치온 함량과 GST 활성은 B $\alpha$)P 단독군에서는 감소되었다가 팽화홍삼분말 투여 시 유의적인 증가를 보였다. 그러나 cytochrome P-450 활성과 지질과산화물 함량은 B ($\alpha$)P 투여 시 증가되었다가 팽화홍삼분말의 투여 시 유의적으로 감소되었다. 특히 홍삼분말보다 팽화시킨 홍삼분말에서 더 큰 항산화능을 보였다. 이상의 결과로 팽화홍삼분말은 항산화 효소의 활성에 의한 B($\alpha$)P에 의한 간 손상에 대한 보호효과를 가지는 것으로 사료된다.

• 한국초전도ㆍ저온공학회논문지
• /
• 제21권1호
• /
• pp.18-24
• /
• 2019

This study was carried out to investigate the effect of milling of boron (B), which is one of raw materials of $MgB_2$, on the critical current density ($J_c$) of $MgB_2$. B powder used in this study is semi-amorphous B (Pavezyum, Turkey, 97% purity, 1 micron). The size of B powder was reduced by planetary milling using $ZrO_2$ balls (a diameter of 2 mm). The B powder and balls with a ratio of 1:20 were charged in a ceramic jar and then the jar was filled with toluene. The milling time was varied from 0 to 8 h. The milled B powders were mixed with Mg powder in the composition of (Mg+2B), and the powder mixtures were uniaxially pressed at 3 tons. The powder compacts were heat-treated at $700^{\circ}C$ for 1 h in flowing argon gas. Powder X-ray diffraction and FWHM (Full width at half maximum) were used to analyze the phase formation and crystallinity of $MgB_2$. The superconducting transition temperature ($T_c$) and $J_c$ of $MgB_2$ were measured using a magnetic property measurement system (MPMS). It was found that $B_2O_3$ was formed by B milling and the subsequent drying process, and the volume fraction of $B_2O_3$ increased as milling time increased. The $T_c$ of $MgB_2$ decreased with increasing milling time, which was explained in terms of the decreased volume fraction of $MgB_2$, the line broadening of $MgB_2$ peaks and the formation of $B_2O_3$. The $J_c$ at 5 K increased with increasing milling time. The $J_c$ increase is more remarkable at the magnetic field higher than 3 T. The $J_c$ at 5 K and 4 T was the highest as $4.37{\times}10^4A/cm^2$ when milling time was 2 h. The $J_c$ at 20 K also increased with increasing milling time. However, The $J_c$ of the samples with the prolonged milling for 6 and 8 h were lower than that of the non-milled sample.

• 동아시아식생활학회지
• /
• 제21권6호
• /
• pp.830-837
• /
• 2011

This study was carried out to investigate the quality characteristics of yellow layer cake mulberry powder. After making yellow layer cake with mulberry powder, water activity, crumb texture, crumb color, and sensory tests were investigated. After 1 day of storage, Aw of control with weak flour did not show any significant difference, whereas those with 1, 3. 5% mulberry powder showed a significant decrease in Aw. During storage, the Aw values of yellow layer cakes containing mulberry powder were consistent. Hardness, springiness, cohesiveness, and gumminess of the yellow layer cakes containing mulberry powder all decreased compared to those of control. Hardness, springiness, cohesiveness, and gumminess all increased with storage time. Further a higher percentage of mulberry powder was associated with a lower L value, but higher a value. b values were lower in the 1% and 3% mulberry powders, but 5% showed a slightly higher b value. An increase in storage time was associated with decreased L and b values and increased a value. The micrographs of yellow layer cakes with mulberry powder showed a slightly coarser porosity than that of controls. The results of the sensory test showed that the over-all acceptability of 1% mulberry powder cake was the best.

• 한국분말재료학회지
• /
• 제23권3호
• /
• pp.202-206
• /
• 2016

A Ni-Ti-B alloy powder prepared by mechanical alloying (MA) of individual Ni, Ti, and B components is examined with the aim of elucidating the phase transitions and crystallization during heat treatment. Ti and B atoms penetrating into the Ni lattice result in a Ni (Ti, B) solid solution and an amorphous phase. Differential thermal analysis (DTA) reveals peaks related to the decomposition of the metastable Ni (Ti, B) solid solution and the separation of equilibrium $Ni_3Ti$, $TiB_2$, and ${\tau}-Ni_20Ti_3B_6$ phases. The exothermal effects in the DTA curves move to lower temperatures with increasing milling time. The formation of a $TiB_2$ phase by annealing indicates that the mechanochemical reaction of the Ni-Ti-B alloy does not comply with the alloy composition in the ternary phase diagram, and Ti-B bonds are found to be more preferable than Ni-B bonds.

• 한국결정성장학회지
• /
• 제22권5호
• /
• pp.247-253
• /
• 2012

본 연구에서는 zirconium diboride($ZrB_2$)의 소결성 향상을 위해 두 가지 전처리 공정을 사용하였다. 물리적 전처리 공정으로 SPEX mill을 사용하여 as-received $ZrB_2$ powder의 입도를 $2.61{\mu}m$에서 $0.35{\mu}m$까지 감소시킬 수 있었다. 화학적 전처리 공정으로 희석된 불산 용액을 사용하여 $ZrB_2$ powder의 산화도를 4.20 wt%에서 2.22 wt%까지 감소시킬 수 있었다. 소결된 $ZrB_2$의 상대 밀도는 입도와 산화도가 감소함에 따라 증가하였다. $ZrB_2$의 치밀화에는 산화도 보다 입도의 영향이 더 크다는 것을 확인하였다. 두 가지 전처리 공정을 통해 소결 조제의 사용 없이 치밀한 $ZrB_2$ 소결체를 제조하였다. 물리적 화학적 전처리 공정을 사용함으로써 $ZrB_2$의 소결성을 향상시킬 수 있었다.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.1080-1081
• /
• 2006

In this investigation, $B_4C$ based ceramic composites were fabricated by in-situ reaction hot pressing using $B_4C$, TiC SiC powder as starting materials. The reaction synthesized composites by hot pressing at $1950^{\circ}C$ was found to posses very high relative density. The reaction synthesized $B_4C$ composites comprise $B_4C$, $TiB_2$, SiC and graphite by the reaction between TiC and $B_4C$. The newly formed $TiB_2$ and graphite was embedded both inside grain and at grain boundary $B_4C$. The mechanical properties of reaction synthesized $B_4C-TiB_2-SiC$-graphite composites were more enhanced compared to those of monolithic $B_4C$.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2005년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
• /
• pp.34-34
• /
• 2005

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2005년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
• /
• pp.43-43
• /
• 2005

• 한국식생활문화학회지
• /
• 제12권5호
• /
• pp.469-475
• /
• 1997

The modification of rice powder was attempted by treatment of acetic acid and epichlorohydrin to improve the functional properties of baby food. The initial gelatinization temperature of rice powder determined by amylograph was decreased from $79.5^{\circ}C$ to $63^{\circ}C$ by modification. The apparent and maxium viscosity of rice paste at $95^{\circ}C$ before and after modification were increased from 92B.U. to 236B.U. and from 100B.U. to 202B.U., respectively. The light transmittance of modified rice paste was increased from the temperature of $60^{\circ}C$ and by increasing the degree of substitution at the fixed temperature, while decrease more or less by the treatment of epichlorohydrin. The degree of retrogradation of the paste was decreased from 28.7 to 18.0 upon modification. The rate of syneresis of modified rice powder was decreased with increasing the drgree of substitution and ,the extend of epichlorohydrin treatment. Syneresis was not observed when acetylated rice powder whose DS value is 0.048 was treated with 0.25% of epichlorohydrin for the formation of cross-linkage. The addition of modified rice powder in preparation of semi-solid type infant food could improve the quality without lowering overall digestibility.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2013년도 자성 및 자성재료 국제학술대회
• /
• pp.110-110
• /
• 2013