• 콘크리트학회지
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• 제9권1호
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• pp.115-121
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• 1997

본 연구는 NaCl 수용액 중에서 고로 슬래그미분말의 알칼리실리카반응에 대한 팽창억제 특성 및 그의 메카니즘에 관한 것이다. 실험에 사용된 NaCl 수용액의 농도는 0%(수도수), 2.8% 및 20%였으며, 골재는 안산암을 사용하였다. 슬래그는 비표면적이 $4,100cm^2/g.\;5,960cm^2/g$ 및 $7,950cm^2/g$인 3종류를 사용하였고 치환율은 시멘트중량에 대하여 40%, 60%, 70% 및 80%로 하였다. NaCl 수용액에 있어서 슬래그를 첨가한 공시체는 치환율이 많을수록 수축률은 높게 되었고 그의 값은 비표면적이 클수록 높게 나타났다. 슬래그에 의한 알카리실리카반응의 유해한 팽창의 억제는 슬래그의 첨가에 의한 경화 콘크리트의 화학적 수축에 의해서도 달성됨이 확인되었다.

• 생물환경조절학회지
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• 제26권2호
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• pp.133-139
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• 2017

본 연구는 NaCl 및 jasmonic acid(JA) 처리 시 스피아민트(Mentha spicata)의 생육 및 생리적 반응 변화를 조사하고자 실시하였다. 대조구, JA($20{\mu}M$ JA 전처리), JA+NaCl($20{\mu}M$ JA 전처리+ 50mM NaCl), NaCl(50mM NaCl) 처리 등 4처리구로 구분하여 0.5배 Hoagland 용액에서 3주간 수경 재배한 후 생장반응과 엽록소, 비타민 C, 프롤린, 무기물, DPPH 라디칼 소거 항산화 활성 등을 측정하였다. 스피아민트의 초장, 엽장, 엽폭 및 생체중은 대조구에 비해 모든 처리구에서 감소하였고, 특히 NaCl 처리구에서 현저히 감소하였다. 반면에 건물중은 JA+NaCl 혼용처리구를 비롯하여 모든 처리구에서 증가하였다. 엽록소 a와 b 함량은 JA 처리구가 가장 높았으나 비타민 C와 항산화 활성 및 지상부의 프롤린 함량은 염 스트레스로 생육이 가장 낮았던 NaCl 처리구에서 가장 높게 나타났다. 이온 흡수의 균형 정도를 알 수 있는 K/Na 비율은 JA 단독 처리 시 증가하였고, NaCl처리 및 JA+NaCl 혼용 처리구에서는 $Na^+$ 흡수 증가로 인하여 K/Na 비율이 낮아졌다. 이러한 결과는 낮은 염 스트레스나 JA처리 같은 적절한 스트레스 처리가 항산화 활성과 정유를 포함하는 이차대사물질의 축적을 유도함으로써 스피아민트의 품질을 향상시킬 잠재적인 가능성을 보여준다.

• Journal of Microbiology and Biotechnology
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• 제30권1호
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• pp.62-70
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• 2020

Zygosaccharomyces rouxii is an important yeast that is required in the food fermentation process due to its high salt tolerance. In this study, the responses and resistance strategies of Z. rouxii against salt stress were investigated by performing physiological analysis at membrane level. The results showed that under salt stress, cell integrity was destroyed, and the cell wall was ruptured, which was accompanied by intracellular substance spillover. With an increase of salt concentrations, intracellular Na⁺ content increased slightly, whereas intracellular K⁺ content decreased significantly, which caused the increase of the intracellular Na⁺/K⁺ ratio. In addition, in response to salt stress, the activity of Na⁺/K⁺-ATPase increased from 0.54 to 2.14 μmol/mg protein, and the ergosterol content increased to 2.42-fold to maintain membrane stability. Analysis of cell membrane fluidity and fatty acid composition showed that cell membrane fluidity decreased and unsaturated fatty acid proportions increased, leading to a 101.21% rise in the unsaturated/saturated fatty acid ratio. The results presented in this study offer guidance in understanding the salt tolerance mechanism of Z. rouxii, and in developing new strategies to increase the industrial utilization of this species under salt stress.

• Journal of Nutrition and Health
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• 제26권9호
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• pp.1118-1128
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• 1993

This study was undertaken to investigate the acute effect of caffeine consumption on the change of mineral concentration in serum and urinary mineral excretion in healthy young females. On two separate mornings at one week intervals, each subject drank a coffee which contained no caffeine and 3mg/kg body weight caffeine. To obviate dietary effects on mineral concentration in serum and urine, each subject fasted at least ten hours before consuming the test beverage. At one, two, three and four hours, serum and urine production collected seperately for measurement of sodium, potassium, calcium, phosphorus and magnesium concentration. The results were as following : 1) Mean age of subjects was 20.6$\pm$0.32, Mean body mass index of subjects was 21.64$\pm$0.89, which was within $\pm$10% of ideal body weight. 2) Total urine volume of caffein groups for 4 hour after caffeine consumption was higher than that of decaffeine one, but urine pH was unchanged after caffeine consumption. Total urinary four hour excretion of creatinine was not affected by caffeine consumption and creatinine clearance also was not different from the control value. 3) In serum, mean three hour content of sodium(p<0.01) and phosphorus was higher in the subject given the caffeine. Mean serum magnesium and calcium contents were lower in caffeine group than that of decaffeine one. Mean serum magnesium content for three hour after caffeine ingestion was affected by caffeine consumption(p<0.001). Mean serum content of potassium was unaffected by caffeine consumption. 4) Total urinary four hour excretion of sodium, increased significantly after caffeine consumption(p<0.05), while total urinary four hour excretion of potassium, calcium, phosphorus and magnesium was unchanged after caffeine intake. Urinary excretion of Na, Ca, P and Mg was greatest at one hour after caffeine consumption, especially urinary sodium and potassium excretion was significantly high(p<0.05, p<0.01). The above results show that only 3mg caffeine per kg body weight increase the urinary macro mineral excretion in healthy young females.

• 한국식생활문화학회지
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• 제36권5호
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• pp.512-521
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• 2021

This study investigated the quality characteristics of sweet pumpkin after blanching. Sweet pumpkins were blanched in distilled water, 2% citric acid and 2% NaCl water at 100℃ for 3 min. The cooking loss of sweet pumpkin in the blanching groups was lower than that in the control group, and greenness and yellowness in the blanching groups were higher than those in the control group (p<0.001). Total polyphenol content (TPC) of sweet pumpkin increased after blanching (p<0.05), and TPC true retention (TR) was measured with the highest NB. CON and NB were significantly higher in ?-carotene content (p<0.001). Lutein content in the blanching treatment groups was lower than that in the control group, but NB was the highest between the blanching groups (p<0.001). DPPH and ABTS⁺ radical scavenging activity assays revealed higher antioxidant activity in the NB groups among the blanching groups (p<0.001). The CON was 2.44 log colony-forming unit (CFU)/ g in the total bacterial count, but there were no microorganisms in the blanching groups. In conclusion, blanching with the addition of 2% NaCl can inhibit the growth of microorganisms and improve TR and antioxidant activities in sweet pumpkin.

• 한국식품저장유통학회지
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• 제30권6호
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• pp.969-982
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• 2023

This study evaluated the impact of blanching pak choi stems and leaves in various solutions (distilled water, 2% NaCl, and 2% citric acid) at 100℃ on their quality characteristics. The highest stem heating loss was observed in the sodium chloride solution (S-NB) at 15.10% (p<0.001), and the highest leaf heating loss was in L-NB at 11.44% (p<0.001). No significant variation was found in the moisture content of both stems and leaves. Relative to the control, the L value (lightness) of the stem decreased while the b value (yellowness) increased (p<0.05). In the leaves, the a value (redness/greenness) and b value increased in L-CB, whereas they decreased in other groups (p<0.05). S-NB exhibited the highest true retention (TR) of total polyphenol content (TPC) in stems (p<0.01) and the highest TR of total flavonoid content (TFC) as well (p<0.001). For leaves, the highest TR of TPC and TFC was in L-WB (p<0.001). In terms of antioxidant activity, S-NB in stems and L-WB in leaves showed the highest scavenging activity measured by DPPH and ABTS⁺ assays (p<0.001). Microorganisms were absent in all pretreatment groups but present in the control. The results suggest that blanching pak choi stems in 2% NaCl solution and leaves in water optimally preserves biologically active compounds and nutrients.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.108-112
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• 1993

The term Alkali-Silica Reaction (ASR) is used to describe a reaction between certain siliceous aggregates and hydroxyl ions present in the pore fluid of a concrete. The ASR is affected by the content of alkali, the particle size and the content of reactive aggregate, water-cement ratio, humidity, temperature and so on. In this paper, the fluence of alkali content and kind of added alkali to the ASR was studied. As a result, the more the content of alkali was increased, the more the mortar-bar was expand and the expansion of mortar-bar was showed differently with the added alkali kinds, The reaction products by ASR were observed by SEM(Scanning Electron Microscope) and analyzed by EDXA(Energy Dispersive X-ray Analysis) also and showed a gel composed of alkali(Na+, K+), silica and calcium.

• 한국식품과학회지
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• 제37권2호
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• pp.312-317
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• 2005

천일염의 저장에 따른 구성 성분들의 변화를 조사하기위하여 서해안 영광군 염산과 백수염전에서 생산된 1-5년산 천일염의 수분, 염도, pH, 무기질, 중금속, 색도 등을 측정하였다. 염산과 백수 천일염의 수분함량은 각각 6.07-17.02%와 4.29-16.15%를 함유하고 있었으며 연령이 높을수록 수분함량이 낮아졌다. NaCl 함량은 저장기간이 증가할수륵 증가하여 염산과 백수의 5년산의 NaCl 함량은 각각 92.74와 94.58%로 증가하였다. 1년산 염산과 백수 천일염의 pH는 각각 6.31과 6.23으로 시약이나 재제염 보다 약간 높았으며 저장기간 길수록 낮은 값을 나타내었다. 대부분의 무기질은 저장연수가 높을수록 낮은 함량을 나타내었는데 5년산 염산과 백수 천일염의 Mg함유량을 1년산보다 각각 약 78과 93%가 적은 2,896과 1,002ppm를 나타내었으며 K의 경우 염산의 5년산은 1년산보다 약 65%, 백수는 약 68%정도 낮은 함량을 보였다. 또한 Ca도 염산과 백수 천일염에서 5년산은 1년산과 비교할 때 각각 41.5%와 43.2%정도 낮은 함량을 보였다. 미량을 함유하고 있는 다른 무기질도 5년산과 1년산을 비교할 16-80%정도 낮은 함량을 나타냈다. 중금속 중 다른 중금속에 비해 높은 함량을 갖는 As는 0.06-0.44ppm이였으며 연령이 높은 소금에서 낮은 함량을 나타냈으며 Cd(0.02-0.04ppm)는 저장에 따른 큰 변화는 없었다. Pb는 1년산에서 0.05-0.11ppm을 함유하고 있었고 연령이 높을수록 함량이 낮아져 5년산에는 검출되지 않았다. 천일염의 색도는 저장기간이 길수록 밝은 백색을 띠었으며 Hunter값 L이 증가하였다.

• 광물과 암석
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• 제35권4호
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• pp.457-467
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• 2022

전자현미분석기를 이용한 규산염 유리의 정량화학조성 분석 시 알칼리 원소, 특히 Na이 전자빔에 의해 분석 영역 밖으로 이동(migration)하면서 X선 측정 세기가 시간에 따라 감소하는 현상은 오래 전부터 알려져 왔다. EPMA로 규산염 유리의 Na 함량을 정확하게 측정하기 위해서는 전자빔에 의한 Na 이동을 최소화하는 분석방법을 적용하거나 Na 이동에 따른 X선 측정 세기의 감소 효과를 보정해 주어야 한다. 본 연구에서는 X선 세기의 시계열 변화 곡선을 이용해 Na 이동에 의한 X선 감소를 보정할 수 있는 Probe for EPMA 소프트웨어의 Time Dependent Intensity(TDI) 보정 기능을 이용해 규산염 유리 표준시료 8종의 Na을 분석하였다. 일반적인 지질시료 분석 조건인 15 kV 가속전압, 20 nA 전류 세기 하에서 TDI 보정의 정확도를 검증하였다. 연구 결과 20 ㎛ 크기의 큰 전자빔을 사용했을 때는 Na 감소가 거의 일어나지 않아 보정 없이도 Na의 함량을 정확하게 측정할 수 있었다. 빔의 크기가 10 ㎛ 이하일 때는 Na 감소가 일어나 최대 -55%에 달하는 큰 오차가 발생하는데 TDI 보정을 적용해 이 오차를 ±10% 이내로 줄일 수 있다. Na X선 시계열 변화의 초기 측정값에 가중치를 주고 변화 추세를 선형적으로 가정하는 방법을 사용하면 상대오차를 ±6% 이내로 더 줄여 정확한 Na₂O 함량을 얻을 수 있었다. 따라서 알칼리 원소가 많이 포함된 유리질 시료에서 분석 영역이 충분히 크지 못해 작은 전자빔을 사용해야만 한다면 적절한 TDI 보정을 반드시 해주어야 정확한 조성을 얻을 수 있다.

• 한국작물학회지
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• 제60권2호
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• pp.253-256
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• 2015

This study was performed to investigate the growth characteristics and inorganic components of Codonopsis lanceolata regarding regional differences. The plant height of Japanese Codonopsis lanceolata was 373.6 cm, so it's revealed that it has more vigorous growth than Korean won. The flowering time of Korean Codonopsis lanceolata was 2 weeks faster than Japanese one. Total fresh weight of root was 41.0 g and 39.0 g for Korean and Japanese respectively, thus, no significance difference was found. However, regarding fresh weight, Korean one had a more fresh weight (35.4 g) of main root parts, but Japanese one had a more fresh weight (9.6 g) of the lateral root part. Each inorganic component was found more in the aboveground parts, regardless of the region and the content of K was the largest. Regarding the content of macroelements for each part of Codonopsis lanceolata, the content of Na, Mg, P, S, and Ca in Korean Codonopsis lanceolata was found the highest on the leaf, followed by stem and root. In the case of Japanese Codonopsis lanceolata, same result was found on the content of Mg and Ca, however, the highest content of Na and P was found in the stem.