• 한국세라믹학회지
• /
• 제50권3호
• /
• pp.201-205
• /
• 2013

Magnesium hydroxide sulfate hydrate ($5Mg(OH)_2.MgSO_4{\cdot}3H_2O$, abbreviated 513 MHSH) whiskers were synthesized using MgO and $MgSO_4.7H_2O$ as reactants without addition of basic solution. Previously, MHSH whiskers were prepared by hydrothermal method using $MgSO_4$ in aqueous ammonia. In this work, for the first time, we synthesized a high purity MHSH via ambient pressure. In addition, a high molar ratio of $MgSO_4$ : MgO is an important key to the formation of high purity MHSH. Also, it was possible to prepare whiskers with high aspect ratio using an increasing reaction time in the reaction between the remaining $SO_4^{2-}$ ions and the ${Mg(OH)_6}^{4-}$ fragment, finally producing one-dimensional whiskers.

• Mycobiology
• /
• 제42권1호
• /
• pp.59-65
• /
• 2014

Entomopathogenic fungi are promising pest-control agents but their industrial applicability is limited by their thermosusceptibility. With an aim to increase the thermotolerance of Isaria fumosorosea SFP-198, moisture absorbents were added to dried conidial powder, and the relationship between its water potential and thermotolerance was investigated. Mycotized rice grains were dried at $10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$, and $40^{\circ}C$ and the drying effect of each temperature for 24, 48, 96, and 140 hr was determined. Drying for 48 hr at $10^{\circ}C$ and $20^{\circ}C$ reduced the moisture content to < 5% without any significant loss of conidial thermotolerance, but drying at $30^{\circ}C$ and $40^{\circ}C$ reduced both moisture content and conidial thermotolerance. To maintain thermotolerance during storage, moisture absorbents, such as calcium chloride, silica gel, magnesium sulfate, white carbon, and sodium sulfate were individually added to previously dried-conidial powder at 10% (w/w). These mixtures was then stored at room temperature for 30 days and subjected to $50^{\circ}C$ for 2 hr. The white carbon mixture had the highest conidial thermotolerance, followed by silica gel, magnesium sulfate, and then the other absorbents. A significant correlation between the water potential and conidial thermotolerance was observed in all conidia-absorbent mixtures tested in this study (r = -0.945). Conidial thermotolerance in wet conditions was evaluated by adding moisturized white carbon (0~20% $H_2O$) to conidia to mimic wet conditions. Notably, the conidia still maintained their thermotolerance under these conditions. Thus, it is evident that conidial thermotolerance can be maintained by drying mycotized rice grains at low temperatures and adding a moisture absorbent, such as white carbon.

• 미생물학회지
• /
• 제30권3호
• /
• pp.154-159
• /
• 1992

섬유소 분해능이 우수한 P. verruculosum 의 분생포자로부터 원형질체의 생성 및 재생에 대하여 조사하였다. 균의 원형질체 생성을 위한여 2-deoxy-D-glucose(2-DG) 가 첨가된 최소배지에서 분생포자를 10-12 시간 전배양 시킨후 시판 세포벽분해효소들을 작용시켜 본 결과 그중 Novozyme 234 (1%, w/v) 에서 50% 이상의 가장 좋은 원형질체 생성 수율을 보였다. 전배양 되지 않은 포자로부터는 원형질체 생성이 이루어지지 않았으며 원형질체 생성율을 향상시키기 위한 첨가테로서 2-DG 의 효과가 무첨가에 비해 2배 이상의 수율을 증가시켰다. 포자 원형질체의 재생율은 49.2% 로 동 균주의 균사체 원형질체의 재생율4.6-27.8%(삼투압 조절체로서 0.6 M magnesium sulfate) 보다 높았다. 원형질체 생성 및 재생을 위한 상투압 안정제로서는 0.6M ammonium sulfate 와0.6 M magnesium sulfate가 가장 적절하였다. 광학 형미경을 통하여 부풀린 포자로부터 원형질체의 생성과정과 두 가지 각기 다른 양상의 재생과정이 관찰되었다.

• 한국대기환경학회지
• /
• 제12권1호
• /
• pp.79-90
• /
• 1996

Total suspended particles were measured at Kosan, Cheju Island, Korea during the period of March 11 .sim. April 19, 1994. Concentrations of non-sea salt(nss) ions were higher than those measured at clean marine areas in Japan and other background marine areas in the world. Especially, nss sulfate concentration is compatable to thoes measured at Seoul. It is suggested that most nss sulfate concentration is originated from anthropogenic sources. Nss sulfate concentration shows strong correlation with ammonium and nss potassium concentrations while shows no a pparent correlation with nitrate and nss calcium concentrations. Nss calcium concentrations shows strong correlation with nss potassium and mss magnesium concentrations. It is deduced that nss potassium has two origins, one anthropogenic, the other crustal. Backward trajectory analysis results show the trajectories of air parcel during the measurement period were mostly originated from China. It is shown that cases of high nss sulfate with high nss calcium can occur when an air parcel originated from arid and semi-arid regions of morthwestern China or Mongolia passes through northeastern China.

• 한국버섯학회지
• /
• 제11권4호
• /
• pp.181-186
• /
• 2013

${\gamma}$-Aminobutyric acid(GABA) is a four carbon non-protein amino acid that has several well-known physiological functions, such as a postsynaptic inhibitory neurotransmitter in the brain and induction of hypotensive and tranquilizer effects. A lactic acid bacterium was isolated from button mushroom bed, which is showing high GABA productivity by TLC or HPLC analysis. The strain was identified as Lactobacillus hilgardii by analysis of 16S rDNA gene sequence. When the maximum production of GABA by L. hilgardii was investigated with various concentration of monosodium glutamate, the yield of GABA reached to be 53.65 mM at 1% mono sodium glutamate (MSG) in flask cultivation. A Glutamate decarboxylase (GAD) enzyme, which was known to convert MSG to GABA, was purified from a cell-free extract of L. hilgardii and the molecular weights of purified GAD was estimated to 60,000 by SDS-PAGE. The optimum pH and temperature of GAD were at pH4.6 and at $37^{\circ}C$, respectively. The GAD activity was increased by the addition of sulfate ions such as ammonium sulfate, sodium sulfate and magnesium sulfate, indicating that the increase of hydrophobic interaction causes the increase of GAD activity.

• 한국식품저장유통학회지
• /
• 제10권4호
• /
• pp.554-559
• /
• 2003

동치미로부터 분리된 Latobacillus sp. FF-3의 Bacteriocin 생산에 대한 최적 배양조건과 배양 특성을 조사하였다. Bacteriocin 생산을 위한 최적 생산조건은 MRS(proteose peptone 1%, beef extract 1%, yeast extract 0.5%, glucose 2%, polysorbate 80 0.1%, ammonium citrate 0.2%, sodium acetate 0.5%, magnesium sulfate 0.01%, manganese sulfate 0.005%, dipotassium phosphate 0.2%) 배지를 기본으로 하여 21시간 배양한 결과, 배양온도는 30∼37$^{\circ}C$, 초기 pH는 7.0 으로 확인되었다. 최적 생산배지조성으로 탄소원은 glucose 3%, 질소원은 tryptone 4%, 무기염류는 manganese sulfate 0.005%가 bacteriocin 생성에 최적 조성으로 나타났으며, 최적 배지상에서 항균활성은 최대 484 BUf/mL로 나타났다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제29권1호
• /
• pp.98-106
• /
• 2005

The chemical conversion film formed on magnesium alloy was investigated by using the colloidal silica with some parameters such as solution pH. temperature, solution conditions, and treatment time. Moreover. the solutions consisted of colloidal silica titanium sulfate, and cobalt ions were used for the colloidal silica film to having a good corrosion resistance and adhesion properties. It was thought that the film at 298K was made with combination of Si-O. The quantity of film formed at high temperature such as 333K and 353K is smaller than dissolved quantity during chemical conversion treatment. Adding $CoSO_4$ to the colloidal silica solution enhanced the adhesion force between the silica film and magnesium substrate, The optimum conditions for the chemical conversion treatment solution were PH 2.90 s treatment, and 298K.

• 아시안잔디학회지
• /
• 제8권3호
• /
• pp.193-199
• /
• 1994

Effect pf rape seed oil cake compast (OM) active carbon(C) compound fertilizer (NPK) and magnesium sulfate (Mg) application on Zoysia koreana growth by lysimeter of 50cm soil column filled with a low fertility loam. Effect on growth was in order of OM>OM . NPK interaction> NPK . active carbon and Mg were not effective OM . NPK interaction effect was negative on leaf width and root dry matter yield. OM and OM . NPK interaction were most effective on rhizome growth. Their effect did not change the ratio of growth rates between aerial part and rhizome but change that between aerial part and root. Leaf width was most sensitive to the treatments.

• 분석과학
• /
• 제31권1호
• /
• pp.47-56
• /
• 2018

사건 현장에 남겨진 혈흔을 찾는 것은 사건을 재구성하거나 해결하기 위해서 매우 중요하다. 사건현장에서 사용할 수 있는 수많은 시약들이 개발되었지만, 루미놀이 가장 대표적인 시약이라고 할 수 있다. 최근에는 블루스타라는 시약이 주로 사용되고 있지만, 가격이 비싸고 시약을 제조한 후 보관이 불가능하다는 단점이 있다. 본 연구에서는 블루스타 수준의 발광강도를 유지하면서 제조 후 장시간 보관할 수 있는 새로운 루미놀 시약을 개발하고자 했다. 루미놀은 알칼리 수용액에서 잘 녹기 때문에, 시약을 제조할 때 수산화나트륨의 사용은 과산화수소의 분해를 촉진시킬 수 있다. 루미놀 시약을 제조할 때 과산화수소 안정화제로 황산마그네슘, 규산나트륨, 삼인산칼륨을 농도별로 첨가한 후, 혈흔과 반응할 때 시약의 발광강도 및 보관기간에 미치는 영향을 확인했다. 과산화수소 안정화제 첨가는 발광강도에 별다른 영향을 주지 않았고, 보관 중 루미놀 시약의 pH를 일정하게 유지시켜 줌으로서 시약의 보관기간을 크게 늘려줬다. 과산화수소 안정화제로 황산마그네슘이 가장 적절하였다. 과산화수소 대신 과붕산나트륨을 산화제로 사용했을 경우, 희석 혈흔에 대한 민감도와 발광강도에 큰 변화는 없었지만 제조 후 보관기간이 단축되었다. 그렇지만, 혈흔과 반응한 후 혼합액의 pH 상승 폭이 과산화수소로 제조한 시약보다 줄어들었다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제1권1호
• /
• pp.51-53
• /
• 1996

Fed-batch culture of Pseudomonas oleovorans was carried out for the production of medium-chain-length polyhydroxyalkanoates (MCL-PHAs) using octanoate as a carbon source. Octanoate and the salt solution containing ammounium sulfate and magnesium sulfate were intermittently fed in the course of fermentation. Cell mass and PHA concentrations of 42.8 and 16.8g/L, respectively, could be obtained in 40 h. The PHA content and the PHA productivity were 39.2% and 0.42 g PHA/L-h, respectively. The yields of cell mass and PHA were 0.71 g dry cell mass/g octanoate and 0.28g PHA/g octanoate, respectively. Therefore, octanoate can be used for the production of MCL-PHAs to a high concentration with high productivity.