• 한국약용작물학회지
• /
• 제26권1호
• /
• pp.55-63
• /
• 2018

Background: The present study assessed the response of kenaf (Hibiscus cannabinus L., Jangdae) seed to NaCl and the effects of polyethylene glycol (PEG) on kenaf seed germination and vigor. Methods and Results: Seed germination ranged from 11.3% to 58.8% after 24 hours of immersion in NaCl concentrations from 0% to 0.5%. The priming treatments had lower electrical conductivity (EC) values for the seeds than for the control and a deteriorated palisade layer. Priming in 10% PEG for 48 hours increased the germination upto 96.3% in $H_2O$ solution and 98.8% in 0.3% NaCl solution compared to that of the control (78.8%). Germination synchronization, and shoot and root growth of the primed seeds were greater than those of the control. The $T_{50}$ of the control in $H_2O$ and 0.3% NaCl solution was 22 and 28 times, respectively. After priming, nine times was sufficient to reach $T_{50}$ in both solution. The mean number of days to germination (MDG) decreased from 1.43 days for the control to 0.55 days for 0% PEG in $H_2O$ solution and from 1.57 days for the control to 0.56 days for 0% PEG in 0.3% NaCl solution. The dry weight after the 10% PEG treatment was higher than that of the control. Conclusions: Taken together, 10% PEG treatment for 24 hours is recommended for kenaf seed invigoration before planting.

• 과학교육연구지
• /
• 제33권2호
• /
• pp.317-320
• /
• 2009

부피 측정법을 이용하여 산 염기 적정 실험에서 중화점을 측정할 때, 나는 용액의 부피 변화에 대한 한국 대학생들의 개념을 조사하였다. 이 연구에 의하면, 대부분의 대학생들은 산 염기 적정 동안 중화반응에 의해 물이 생성되기 때문에 부피가 증가한다는 오개념을 갖고 있었다. 그러나 이것은 용액에 있는 염에 의한 효과를 무시한 것이기 때문에, 부피 변화를 설명하는데 충분하지 않다. HCl/NaOH 중화반응 동안 용액의 부피 증가를 설명하기 위해, 나는 생성된 NaCl의 부분 몰부피를 계산하였다. 실험 결과와 계산된 부분 몰부피를 비교할 때, 나는 부피 증가의 주요 효과는 HCl/NaOH 중화반응 동안 생성된 NaCl의 부분 몰부피 때문이라는 것을 밝혔다. 여기서 산 염기 중화 적정 동안 용액의 부피 변화에 대한 오개념을 줄이기 위해, 나는 부분 몰부피의 개념을 대학생들에게 도입하도록 제안한다.

• Journal of Electrochemical Science and Technology
• /
• 제14권1호
• /
• pp.59-65
• /
• 2023

Sodium hydroxide solutions are often employed as sterilization agents in the pharmaceutical industry. Here, the chloride content is considered as a critical impurity. In this study, an electrochemical method was developed to remove chloride ions (Cl^-) through the oxidative deposition of AgCl on a Ag anode. The Cl^- content in the commercially available 50% w/w NaOH solution employed was approximately 100 mg Cl^-/kg NaOH. As the OH^- content is approximately 18,000 times higher than the Cl^- content, the formation of AgCl may be expected to be thermodynamically less favorable than the formation of Ag₂O. However, activation energies for AgCl and Ag₂O formation have been reported to be approximately 3.8 and 31.2 kJ/mol, respectively, and indicate that AgCl formation is favored. AgCl can be selectively produced by controlling the anode potential. Here, the Cl^- concentration was reduced to less than 50 mg Cl^-/kg NaOH when an anode potential of 0.18 or 0.19 V vs. Hg/HgO (reference electrode) was applied for one hour at 50℃. XRD analysis and visual monitoring of the Ag anode confirmed the oxidative deposition of AgCl on the anode surface as well as the electrochemical desalination of the concentrated NaOH solution.

• Mass Spectrometry Letters
• /
• 제8권1호
• /
• pp.14-17
• /
• 2017

The effect of cationization agent concentration on glycan detection via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was investigated using $Na^+$ ions in the form of NaCl as the cationization agent. NaCl solution concentrations ranging from 1 mM to 1 M were investigated. Glycans from ovalbumin were mixed with the cationization agent solution and the 2,5-dihydroxybenzoic acid (2,5-DHB) matrix solution in a volume ratio of 1:1:1. The resulting mixture was loaded onto the MALDI plate. Two MALDI-TOF MS instruments (Voyager DE-STR MALDI-TOF MS and Tinkerbell RT MALDI-TOF MS) were used for detection of glycans. The best detection, in terms of the number of identified glycans, the peak intensity, and the signal-to-noise (S/N) ratio, was obtained with NaCl concentrations of 0.01-0.1 M for both MALDI-TOF MS instruments.

• Current Research on Agriculture and Life Sciences
• /
• 제2권
• /
• pp.109-114
• /
• 1984

Eight Korean native black goats were used, $10m{\ell}$ of blood was collected from the Jugular vein into heparinized tubes a week interval. The heparinized blood was centrifuged for separation to blood plasma and corpuscles. The hematocrit, per centage of blood that is red blood cells, was reschuffuled of 10 %, 20 %, 30 %, 40 % and 50 % using blood plasma, 0.9 % NaCl solution and 5.4 % dextrose solution. The sedimentation rates of red blood cell obtained at $7^{\circ}C{\pm}1^{\circ}C$ and $27^{\circ}C{\pm}1^{\circ}C$ are summarized as follows. 1) The sedimentation rates of red blood cell were more increased by lower PCV%, i.e. there was a reverse relationship between the sedimentation rates and PCV% at any condition of these experiments. 2) The RBC were sedimented the most quickly in the NaCl solution and slower in the plasma compare with the dextrose solution at the same PCV%. 3) There was no temperature effect on the sedimentation rates between the two groups of $7^{\circ}C{\pm}1^{\circ}C$ and $27^{\circ}C{\pm}1^{\circ}C$(at PCV 20% and 10%), even though the temperature difference is $20^{\circ}C$.

• 한국식품영양학회지
• /
• 제25권2호
• /
• pp.393-397
• /
• 2012

본 연구에서는 온도 변화 방법을 이용하여 조미계란을 신속하게 제조하기 위한 가염방법을 개발하고자 하였다. 먼저 염지액의 농도에 따른 계란 내부로 염분의 침투 효과를 분석한 결과, 20, 30 및 40%의 염지액에서 2시간 동안 염지시킨 각각의 계란내 염분 함량은 0.51, 0.57 및 0.60%를 나타내어 농도가 높아질수록 침투효과가 향상되는 것을 확인할 수 있었으며, 고온에서 저온으로 계란의 온도 변화를 유도한 온도변화 방법을 적용한 경우 2시간 동안 계란내 염분 함량이 각각 0.49, 0.56 및 0.70%를 나타내어 40%의 염지액에서 염분의 침투 효과가 향상되었다. 그리고 4, 5 및 7 MPa의 압력을 가하여 40%의 염지액으로 15분간 염지한 경우, 각각 1.14, 1.36 및 1.45%의 염분 함량을 나타내어 대기압 조건에서 침투시킨 결과보다 빠르게 침투되었다. 온도 변화 방법을 적용하여 4, 5 및 7 MPa의 압력을 가하여 40%의 염지액으로 15분간 염지한 경우 각각 1.52, 1.62 및 1.66%의 염분 함량을 나타내어 온도 변화 방법에 의해 침투 효과가 향상됨을 확인할 수 있었다. 이는 계란의 온도 변화 방법이 계란 내부 난막의 수축효과로 외부 염분의 흡입을 유도하였기 때문으로 생각되며, 조미계란을 신속하게 제조하기 위한 가염 방법으로 온도 변화 방법의 적용이 매우 효과적이라고 생각된다.

• 자원리싸이클링
• /
• 제17권6호
• /
• pp.17-23
• /
• 2008

염화 제 2철용액에 의한 구리황화광의 침출액을 모사하기 위해 $FeCl_3$-$FeCl_2$-$CuCl_2$-CuCl-NaCl-HCl-$H_2O$의 조성을 지닌 합성용액을 제조하였다. 합성용액에서 염화철과 염화구리의 농도를 0.1에서 1 m까지 변화시키며 성분의 농도변화에 따른 $25^{\circ}C$에서 용액의 pH와 전위의 변화를 측정하였다. 염산의 농도가 일정한 조건에서 CuCl의 농도를 증가시키면 용액의 pH는 증가하였다. 그러나 염산과 CuCl의 농도가 일정한 조건에서 다른 용질의 농도를 증가시키면 수소이온의 활동도계수가 증가하면서 용액의 pH는 감소하였다. CuCl의 농도를 증가시키면 염화 제 1구리이온이 안정해지는 방향으로 반응이 진행하나 $FeCl_3$은 반대의 효과를 나타냈다.

• 방사성폐기물학회지
• /
• 제19권1호
• /
• pp.1-7
• /
• 2021

The pH dependence of sorption distribution coefficient (Kd) of Np(IV) on MX-80 in Ca-Na-Cl type solution with the ionic strength of 0.3 M, which was similar to one of the reference groundwaters in crystalline rock, was experimentally investigated under the reducing conditions. The overall trend of Kd on MX-80 was independent of pH at 5 ≤ pH ≤ 10 but increased as pH increased at pH ≤ 5. The 2-site protolysis non-electrostatic surface complexation and cation exchange model was applied to the experimentally measured pH dependence of Kd and the optimized surface complexation constants of Np(IV) sorption on MX-80 were estimated. The values of surface complexation constants in this work agreed relatively well with those in the Na-Ca-Cl solution previously evaluated, suggesting that compared to Na+, the competition of Ca2+ with Np(IV) for surface complexation on MX-80 was not much strong in Ca-Na-Cl solution. The sorption model well predicted the pH dependence of Kd values but slightly overestimated the sorption at the low pH region.

• Geomechanics and Engineering
• /
• 제25권3호
• /
• pp.245-251
• /
• 2021

The present study investigated the ageing effect on compressibility, permeability and shear strength behavior of kaolin and bentonite samples in the presence of NaCl and CaCl₂ solutions. The compressibility, permeability and shear strength parameters were determined on the 60, 190, and 250 days cured samples. The results have shown that, the kaolin sample becomes more compressible in the presence Ca²⁺ ions with ageing. Generally, the normalized compression index values of bentonite samples increased at the end of 60 days and 250 days curing time periods. The normalized permeability value of kaolin decreased by ageing in the presence of Na⁺ ions almost twofold. The permeability values of bentonite increased both in NaCl and CaCl₂ solutions during ageing. In the presence of Na⁺ ions kaolin had higher max. shear stress value than Ca²⁺ ions. When the max. shear stress values of 0, 60 and 190 days samples were compared, it was seen that NaCl solution had no significant effect on the shear strength of kaolin sample. However, the shear strength of kaolin increased in the CaCl₂ solution during ageing. In the presence of Ca²⁺ ions the max. shear stress value of bentonite was higher. The results of this study have shown that ageing has significant effects on the compressibility, permeability and shear strength of kaolinitic and bentonitic clayey soils.

• 한국생활과학회지
• /
• 제7권1호
• /
• pp.197-203
• /
• 1998

Sucrose, NaCl, citrate, caffeine 및 MSG의 용액을 준비한 뒤 관능검사를 통하여 최소감미량을 측정하였고, 네 가지 기본맛과 MSG의 상호작용을 알아보기 위하여 세 가지 다른 강도의 기본맛 용액과 MSG를 혼합시킨 뒤 맛의 강도 변화를 조사하였다. 기본맛의 최소감미량은 단맛은 0.451%, 짠맛은 0.01%, 쓴맛은 0.005%, 그리고 신맛은 0.004%로 측정되었고, 최소감미량 농도가 가장 큰 것은 단맛, 가장 작은 것은 신맛으로 나타났다. MSG의 최소감미량은 0.033%로 짠맛 최소감미량의 약 3배 정도였다. MSG첨가에 의한 네 가지 기본맛 성분의 맛강도 변화를 알아 본 결과는 다음과 같다. 강도 10인 10% Sucrose 용액에 0.8%의 MSG가 혼합되었을 때 단맛 강도가 유의적으로 감소하였으며, MSG는 Sucrose의 단맛을 대체로 저하시키는 경향을 나타내었다. NaCl용액에 대해서는 농도에 상관없이 MSG가 짠맛 강도를 유의적으로 증가시키는 경향을 보였다. Citrate용액에 대해서는 신맛강도를 약간 저하시켰으며, 그리고 caffeine용액에 대해서는 MSG가 오히려 쓴맛을 강화시키는 효과를 나타내었다.