• Journal of Plant Biotechnology
• /
• 제32권4호
• /
• pp.301-306
• /
• 2005

패랭이꽃속 Dianthus gratianopol 잎절편체로부터 캘러스를 유기하여 표면에 광택이 있고 치밀하게 배열되고 연한 녹색의 shoot-forming 캘러스를 선별하였다. 유기된 캘러스를 잘게 자르고 1.0 mg/L 2,4-D와 0.5 mg/L BAP가 포함된 CP 액체배지에서 7일 간격으로 계대배양하여 균일한 SF형태의 조직이 치밀한 세포괴를 얻을 수 있었고 이들 세포괴를 1.0 mg/L 2,4-D와 0.5 mg/L BAP, 1.5 mg/L 2,4-D와 0.5 mg/L BAP의 MS고체배지에서 배양했을 때 재분화능력이 있는 캘러스를 유도할 수 있었다. 이들 캘러스는 1.0mg/L TDZ과 0.5 mg/L PAA가 포함된 MS재분화배지에 치상하였더니 녹화되기 시작하여 배양 4주후부터는 다량의shoot 원기가 형성되고 shoot증식이 가능하였으며 평균 87%의 shoot 형성률을 보였다. 배양 9주후 절단된 shoot는 0.1 mg/L NAA가 첨가된 배지에서 뿌리를 형성하여 화뢰와 꽃을 갖고 있는 완전한 식물체로 재분화되었다. 또한 재분화 능력이 있는 캘러스 정단 원기를 절단한 절편체는 1.0 mg/L TDZ 과 0.5 mg/L PAA가 포함된 MS재분화 배지에서 직접 부정아를 형성하였고 이들 부정아로부터 다량의 shoot 증식이 가능하여 식물체를 효과적으로 얻을 수 있었다.

• 대한금속재료학회지
• /
• 제50권6호
• /
• pp.463-468
• /
• 2012

A 71.5 wt%Mg-23.5 wt%Ni-5 wt%$Fe_2O_3$ (Mg-23.5Ni-$5Fe_2O_3$) sample was prepared by a quite simple process, reactive mechanical grinding, and its hydriding and dehydriding properties were then investigated. The reactive mechanical grinding of Mg with Ni and $Fe_2O_3$ is considered to facilitate nucleation and shorten the diffusion distances of the hydrogen atoms. After the hydriding-dehydriding cycling, the Mg-23.5Ni-$5Fe_2O_3$ sample contained $Mg_2Ni$ phase. Expansion and contraction of the hydride-forming materials (Mg and $Mg_2Ni$) with the hydriding and dehydriding reactions are also considered to increase the hydriding and dehydriding rates of the mixture by forming defects and cracks leading to the fragmentation of the particles. The temperature dependence of the hydriding rate of the sample is discussed.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2007년도 춘계학술대회 논문집
• /
• pp.302-305
• /
• 2007

The springback characteristics of AZ31B magnesium alloy sheet was investigated in OSU draw/bend test. Springback is the elastically-driven change of shape of a part after forming and it should be estimated and controlled to manufacture more precise products in sheet forming. The demands are increasing for magnesium alloy sheet press forming, but the study on its springback characteristics is insufficient. Strip draw/bend tests were conducted with various conditions - die radius, sheet thickness and controlled tensile force. The springback angles were measured from 'sidewall curl' of deformed shape. The tendency of springback angle was observed from the tests.

• 소성∙가공
• /
• 제17권7호
• /
• pp.466-472
• /
• 2008

In this paper, tension tests and formability tests are performed to construct a database related to mechanical properties and the formability of the AZ31B Mg alloy sheet. A forming test with a hemi-spherical punch is conducted at varying temperatures to establish a forming limit diagram. In order to verify the applicability of the analysis using the conventional flow hardening model, a finite element analysis is performed on the hemi-spherical punch forming process and the results are compared with experimental ones. The study investigates problems involving a computational analysis that does not consider flow softening of the magnesium alloy at elevated temperatures.

• 펄프종이기술
• /
• 제34권3호
• /
• pp.32-37
• /
• 2002

The paper mill wastewater actually generating bulking was used to apply to the spot. Batch and continuous type pilots were used in this study. Optimal time after propagating generation of activated sludge in aeration basin by adding Hoc forming microorganism was 24 and 36hours while optimal time of activated sludge in original aeration basin was 60hours. Showing the difference of sedimentation velocity at 7th day after operating a pilot continuously, SV30 was decreased to 50% at 13th day. COD value in aeration basin with floe forming microorganism was 35mg/L while COD value in original aeration basin was 52mg/L. It was indicated that application of Hoc forming microorganism can control the bulking of paper mill wastewater by shortening of recovery time and improving of pollution removal efficiency.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 춘계학술대회 논문집
• /
• pp.366-369
• /
• 2008

In this paper, tension tests and formability tests are performed to construct a database related to mechanical properties and the formability of the AZ31B Mg alloy sheet. A forming test with a hemi-spherical punch is conducted at varying temperatures to establish a forming limit diagram. In order to verify the applicability of the analysis using the conventional flow hardening model, a finite element analysis is performed on the hemi-spherical punch forming process and the results are compared with experimental ones. The study investigates problems involving a computational analysis that does not consider flow softening of the magnesium alloy at elevated temperatures.

• 대한환경공학회지
• /
• 제31권7호
• /
• pp.557-564
• /
• 2009

본 연구는 struvite 형성 방법을 이용하여 하수슬러지 내에 함유되어 있는 인을 효율적으로 회수하는 것을 목적으로 하였다. 산의 종류에 따른 인 용출 실험결과, HCl에 비하여 $H_2SO_4$가 2.65배 높은 효율을 나타내었으며, Mg 원과 온도에 따른 struvite 생성물의 침전율은 $25^{\circ}C$에서 $MgCl_2{\cdot}6H_2O$를 Mg원으로 사용한 경우에 97.4%로 가장 높게 나타났다. 또한, 인 회수 과정에서 Fe, Al, Zn 등에 의한 부반응이 일어났으며, 이를 해결하기 위하여 pH 7에서 인 화합물의 침전을 유도하여 부반응 공침전 물질을 다량 제거시킬 수 있었다. Struvite 형성 방법을 통한 최종 인 회수율은 82.99%로 순도 높은 struvite 생성물을 회수할 수 있었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2007년도 추계학술대회 논문집
• /
• pp.91-92
• /
• 2007

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 춘계학술대회 논문집
• /
• pp.395-395
• /
• 2008

• The Korean Journal of Ceramics
• /
• 제3권4호
• /
• pp.269-273
• /
• 1997

Chemical composition of cement powder influences the setting time and early compressive strength development. The setting time increases as the amounts of zinc oxide and magnesium oxide are increased. For one day compressive strength development, a cement powder with a composition 90% ZnO, 8% MgO and 2% silica resulted in the highest strength (greater than 1, 090 kg/$\textrm{cm}^2$). Cement-forming liquids also need to be buffered, with both aluminum and zinc ions, for a good consistency and a higher strength of the zinc phosphate cement. These liquids control the setting reactions.