• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.235-247
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• 1998

Calcium sulfate has a long history of medical use as an implant material. The biocompatibiliry of the material has been clearly established. Bone ingrowth concomitant with resorption occurs rapidly with efficient conduction of bone from particle to particle. Calcium sulfate also has a potential for functioning as a good bamer membrane. The purpose of this study was to compare the biocompatibility of different types of calcium sulfate grafting materials including an expelimental calcium sulfate compound on periodontal ligament cells in vitro as a preliminary test towards the development of a more convenient and useful form of grafting material which could promote regeneration of periodontal tissue. Human periodontal ligament cells were collected from the premolar teeth extracted for orthodontic treatment. cells were cultured in a.MEM culture medium containing 20% FBS, at $37^{\circ}C$ and 100% humidity, in a 5% CO2 incubator. Cells were cultured into 96 well culture plate $1{\times}104$ cells per well with $\alpha$-MEM and incubated for 24 hours. After discarding the medium, those cells were cultured in $\alpha$-MEM contained with 10% FBS alone (control group), in medcal-grade calcium sulfate(MGCS group), in plaster(plaster group), experimental calcium sulfate paste(CS paste group) for 1, 2, 3 day respectively. And then each group was characterized by examining of the cell counting, MTI assay, collagen synthesis. The results \vere as follows. 1. In the analysis of cell proliferation by cell counting, both medical-grdde calcium sulfate group and plaster group showed no stastically significant difference at day 1, 2, 3 accept for plaster group at day 1 compared to control group, but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.05). 2. In the analysis of cytotoxicity by MIT assay, both medical-grade calcium sJlfate group and plaster group showed no stastically significant difference compared to control group at day 1, 2, 3 but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.OS). 3. In the analysis of collagen synthesis by immunoblotting assay, high level was detected for medical-grade calcium sulfate group and plaster group at day 1, 2, 3 compared to CS paste group. On the basis of these results, medical-grade calcium sulfate and plaster was shown to possess biocompatibility whereas the CS paste had unfavourable outcome. This observation shows a need for modification of the materials contained in calcium sulfate paste.

• 한국식품저장유통학회지
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• 제18권5호
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• pp.678-683
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• 2011

떫은감 분말 첨가 두부의 수율, 품질 및 저장성에 응고제의 종류(magnesium chloride, calcium chloride, calcium sulfate, glucono-${\delta}$-lactone)가 미치는 영향을 조사하였다. Glucono-${\delta}$-lactone으로 응고시킨 두부가 가장 높은 수율, hardness, chewness, crispness, overall acceptability 및 가장 낮은 L값, b값, pH, 침지저장액 탁도, 총균수를 보였다. Calcium sulfate와 calcium chloride으로 응고시킨 두부는 비교적 높은 L과 b값을 나타내었다. Magnesium chloride로 응고시킨 두부는 관능적 품질특성(firmness, taste, overall acceptability)이 glucono-${\delta}$-lactone 응고 두부와 상호 유의적인 차이가 없이 비교적 높게 평가되었다. 이러한 결과로써 glucono-${\delta}$-lactone과 magnesium chloride가 떫은감 분말 첨가 두부 제조에 적합한 응고제로 판단된다.

• 한국세라믹학회지
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• 제38권5호
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• pp.446-453
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• 2001

본 논문에서는 석고형태에 따른 belite-rich cement(BRC)의 수화성상 및 혼화제의 흡착거동으로부터 시멘트의 유동성에 미치는 영향성을 조사하였다. 또한, 보통 포틀랜드 시멘트(OPC)의 경우와도 그 영향성을 비교 검토하였다. 유동특성을 측정한 결과, 폴리카르복실산계 혼화제 사용시 반수와 이수석고를 첨가한 BRC가 미니슬럼프 값이 약 $\pm$20cm 근방의 수치를 보였으며, 무수석고를 첨가한 것과 OPC에서는 낮은 슬럼프치를 보였다. 초기 수화의 경우, XRD와 DSC에서 Ca(OH)$_2$의 생성량의 정도가 BRC 2-C(반수)>BRC 1-C(이수)>BRC 3-C(무수)의 순서로 줄어들기 때문에 장기강도측면에서도 반수석고와 이수석고를 동시에 사용하는 것이 우수할 것으로 추정된다. 또한 이 결과는 비표면적의 데이터와도 일치함을 보였다.

• 한국세라믹학회지
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• 제37권5호
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• pp.438-443
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• 2000

This dissertation is focused on the study over the improvement for the early strength of belite-rich cement(BRC). For this purpose, the initial hydration behaviors according to addition of different calcium sulfate types were evaluated. From the observations by XRD, DSC and SEM, the BRC II and III with the addition of natural anhydrate and flue gas desulphurization(FGD) gypsum, respectively, formed much ettringite after 7 days more than the BRC I with the addition of chemical gypsum. The compressive strength of the BRC II and III developed outstandingly due to the formation of calcium aluminate hydrate within pores of hardened BRC paste. Especially, in the case of BRC III adding FGD with low impurities, the early as well as long term compressive strengths were shown very high, compared with other specimens.

• 한국수산과학회지
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• 제54권2호
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• pp.218-223
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• 2021

In this study, the possibility of use as a cartridge for 3D printing was confirmed by adding calcium to the alginic acid-added surimi mixture. The Alaska pollack Gadus chalcogrammus surimi added with alginic acid was immersed in a calcium solution (1 M calcium carbonate, 1 M calcium chloride, 1 M calcium sulfate, and 0.1 M calcium lactate) to evaluate the physical properties, color differences, and sensory properties of Alaska pollack surimi according to calcium types. As the results, in the case of surimi paste to which 1 M calcium carbonate was added, physical properties were weaker than that of 1 M calcium chloride, but gelation was appropriate and sensory properties was excellent. Addition of 1 M calcium chloride has the best physical properties, but it has a problem of bitter taste. With the addition of 1 M calcium sulfate, it has low solubility and poor physical properties as well as poor elasticity and bad taste. Addition of 0.1 M calcium lactate has weak physical properties but good sensory properties. From these results, 1 M calcium chloride has the best physical properties, but there is a decisive problem in sensory properties, so 1 M calcium carbonate is most suitable for commercial use.

• 한국토양비료학회지
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• 제24권3호
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• pp.210-218
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• 1991

질소무시용하(窒素無施用下)에서 소석회(消石灰), 고토석회(苦土石灰), 탄산석회(炭酸石灰)는 중화량(中和量), 황산석회(黃酸石灰)는 10a당(糖) 150kg시용(施用)하고 비닐피복후(被覆後) $40{\times}25cm$ 재식거리(栽植距離)로 1989년(年) 4월(月) 26일(日) 파종(播種)하여 호남(湖南) 작시(作試) 선발(選拔) 우량질소(優良窒素) 고정균(固定菌)(B. sp HCR-46)을 종자(種字) 1입당(粒當) $8.2{\times}10^7$ cell의 농도(濃度)로 접종(接種)한뒤 영호(嶺湖)땅콩의 종실성분(種實成分)의 변화(變化)를 조사(調査)한 결과(結果)는 다음과 같다. 1. 땅콩에 착생(着生)한 근류수, 근류건중(根瘤乾重) 그리고 지하부건중(地下部乾重)은 근류균(根瘤菌) 접종(接種)으로 증가(增加)되었으며, 석회비종별(石灰肥種別)로는 탄산석회(炭酸石灰)>고토석회(苦土石灰)>소석회(消石灰)>무시용(無施用)>황산석회순(黃酸石灰順)이었다. 2. 근류균(根瘤菌) 접종(接種)으로 잎과 줄기중(中) T-N, $K_2O$, MgO, Allantoin, Ammonia, 유리(遊離)아미노산함량(酸含量), 엽록소함량(葉綠素含量)은 증가(增加)되었으나 Nitrate 와 줄기중(中) 전당(全糖), 전분(澱粉)의 함량(含量)은 감소(減少)되었다. 3. 잎과 줄기중(中) T-N, 유리(遊離)아미노산(酸), 엽록소함량(葉綠素含量)은 탄산석회시용구(炭酸石灰施用區)에서, $K_2O$, MgO, Allantoin, Ammonia 함량(含量)은 고토석회시용구(苦土石灰施用區)에서, CaO와 Nitrate함량(含量)은 소석회시용구(消石灰施用區)에서 가장 높았다. 4. 줄기중(中) 전당함량(全糖含量)은 황산석회(黃酸石灰)>무시용(無施用)>소석회(消石灰)>탄산석회(炭酸石灰)>고토석회순(苦土石灰順)이었다. 5. 야산개간지(野山開墾地)에서 석회비종별(石灰肥種別) 토양개량효과를 보면 탄산석회(炭酸石灰)는 산도교정력(酸度矯正力)과 Ca공급력(供給力)이 우수(優秀)했으며, 고토석회(苦土石灰)는 Mg공급력(供給力)이 우수(優秀)하였다. 6. 근류균(根瘤菌) 접종(接種)으로 주경장(主莖長), $m^2$당협수가 유의적(有意的)으로 증가(增加)했으며 종실수량(種實收量)은 무접종(無接種)보다 64%증가(增加)되었다. 석회비종별(石灰肥種別)로 보면 주경장(主莖長), 분지수, 종실수량(種實收量)은 탄산석회(炭酸石灰)>고토석회(苦土石灰)>소석회(消石灰)>황산석회(黃酸石灰)>무시용순(無施用順)이었다.

• 농업과학연구
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• 제46권1호
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• 한국대기환경학회지
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• 제19권5호
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• pp.503-513
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• 2003

A single particle analytical technique, called low-Z electron probe X-ray microanalysis (low-Z EPMA) was applied to characterize atmospheric particles collected in Busan, Korea, over a daytime period in Dec. 2001. The ability to quantitatively analyze the low-Z elements, such as C, N, and 0, in microscopic volume enables the low-Z EPMA to specify the chemical composition of individual atmospheric particle. Various types of atmospheric particles such as organics, carbon-rich, aluminosilicates, silicon oxide, calcium carbonate, iron oxide, sodium chloride, sodium nitrate, ammonium sulfate, and titanium oxide were identified. In the sample collected in Busan, sodium nitrate particles produced as a result of the reaction between sea salt and nitrogen oxides in the atmosphere were most abundantly encountered both in the coarse and fine fractions. On the contrary, original sea salt particles were rarely observed. The fact that most of the carbonaceous particles were distributed in the fine fraction implies that their origin is anthropogenic.

• 한국응용과학기술학회지
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• 제26권4호
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• pp.385-393
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• 2009

Different types magnesium hydroxide groups have been obtained using the hydrothermal precipitation technique from magnesium sulfate and calcium carbonate solution. The Mg atom coordinated around O atom of ${SO_4}^{2-}$ in another layer to form a multi-layer structure crystal. The influence of synthesis parameters on the morphological characteristics and size of magnesium hydroxide groups precipitated in aqueous were investigated such as different of additive and pH. Magnesium hydroxide groups were decomposed gradually and converted finally to MgO particles after heated in air temperature up to $1050^{\circ}C$. The particle size and it's distribution morphology, crystal phase and thermal behavior of the samples were characterized through XRD, SEM, EDS, and TG/DTA.

• 콘크리트학회논문집
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• 제27권6호
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• pp.641-649
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• 2015

본 연구는 선행연구에서 도출한 다량의 광물질 혼화재를 사용한 고강도 콘크리트(HVMAC)의 내구성을 3성분계 콘크리트(TBC)와 시멘트만 사용한 콘크리트(NC)에 대해서 비교 평가하고자 하였다. 내구성 평가 종류는 염화물 침투 저항성, 동결융해 저항성, 두가지 전처리 조건으로 비교 평가한 탄산화 저항성, 5% 황산($H_2SO_4$), 10% 황산나트륨($Na_2SO_4$) 및 10% 황산마그네슘($MgSO_4$) 용액을 선정하여 황산 및 황산염 저항성 평가를 수행하였다. HVMAC는 모든 재령에서 우수한 염화물 침투 저항성을 나타내었고, 동결융해에 대한 내구성 지수가 100%에 가까운 우수한 결과를 나타내었다. 탄산화 저항성 평가 결과, HVMAC가 TBC보다 저감효과가 있었으며, 양생기간을 증가시켰을 때 콘크리트 내부조직을 치밀하게 만들어 탄산화 저항성을 향상시켰다. 황산 및 황산염 저항성 평가에서 HVMAC가 가장 우수한 것으로 나타났다. 다량의 혼화재 적용에 따른 수산화칼슘 생성량과 $C_3A$가 적어 황산 및 황산염에 의한 열화가 저감된 효과로 강도 감소 및 질량 변화가 작게 나타난 것으로 확인되었다.