• 한국결정성장학회지
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• 제15권2호
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• pp.86-91
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• 2005

층상 구조의 유기-무기 페로브스카이트 복합 소재 $(C_nH_{2n+1}NH_3)_2CuC1_4$ (n=6, 8, 10, 12)을 합성하였다. $(C_nH_{2n+1}NH_3)_2CuC1_4$ 화합물에서 긴 사슬의 양성자화된 알킬 암모늄 이온은 기울어진 이중층의 구조로 $CuCl_6$ 팔면체의 구석을 공유하고 있는 페로브스카이트형의 층들 사이에의 삽입되었다. 페로브스카이트 층상 화합물에서의 3개의 고체상을 HT-XRD와 DSC를 사용하여 조사하였다. $(C_nH_{2n+1}NH_3)_2CuC1_4$ 화합물은 단계적인 층간거리의 증가와 함께 고체-고체 상전이 현상을 보여준다 3개의 다른 구조는 긴 사슬의 양성자화된 알킬 암모늄 이온의 형태 변화로 설명하였다.

• 한국재료학회지
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• 제11권3호
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• pp.203-206
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• 2001

SrTiO$_3$첨가량 및 소결온도에 따른 YIG 소결체의 미세구조 및 자기적 특성변화에 대하여 조사하였다. 소량의 SrTiO$_3$소결재를 첨가한 결과 소결체의 격자상수는 약간 증가하였으며, 이는 소결시 $Y^{+3}$, Fe$^{+3}$이온이 이온반경이 상대적으로 큰 Sr$^{+2}$, Ti$^{+4}$이온으로 치환되었기 때문인 것으로 추정된다. SrTiO$_3$소결재를 0.2mo1% 첨가하고, 142$0^{\circ}C$에서 소결한 소결체의 밀도는 이론밀도의 98%이상의 치밀화를 얻을 수 있었다. 상온에서의 포화자화값(M$_s$)은 SrTiO$_3$소결재의 첨가량이 증가함에 따라 약간 감소하였으나 큰 변화는 없었다. 더욱이 온도에 따른 보자력 (H$_c$)의 변화는 없었다.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.172-176
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• 2004

A highly selective membrane electrode based on1,3,5-triphenylpyrylium perchlorate (TPPP) is presented. The proposed electrode shows very good selectivity for sulfate ions over a wide variety of common inorganic and organic anions. The sensor displays a nice Nernstian slope of -29.7 mV per decade. The working concentration ranges of the electrode is 1.0{\times}10^{-1}-6.3{\times}10^{-6} $M with a detection limit of $4.0{\times}10^{-6}$ M (480 ng per mL). The response time of the sensor in whole concentration ranges is very short (< 6 s). The response of the sensor is independent on the pH range of 2.5-9.5. The best performance was obtained with a membrane composition of 32% PVC, 59% benzyl acetate, 5% TPPP and 4% hexadecyltrimethylammonium bromide. It was successfully used as an indicator electrode for titration of sulfate ions with barium ions. The electrode was also applied for determination of salbutamol sulfate and paramomycine sulfate.

• 한국환경과학회지
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• 제24권6호
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• pp.785-792
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• 2015

This study investigates weekday/weekend characteristics of $PM_{10}$ concentration and chemical composition of water-soluble ions in Busan in the spring of 2013. Contribution rate of water-soluble ions to PM10 concentration in weekday/weekend were 41.5% and 38.5%, respectively. Contribution rate of SO_4{^{2-}}$ to total ion mass in weekday/weekend were 30.4% and 33.8%, respectively. Contribution rate of total inorganic water-soluble ions in PM10 in weekday/weekend were 42.2% and 39.1% (mean 41.4%), respectively. $[NO_3{^-}/SO_4{^{2-}}]$ ratio in weekday/weekend were 1.01 and 0.97(mean 0.99), respectively, which indicated that weekday ratio was higher. Contribution rate of sea salts and $Cl^-/Na^+$ ratio in PM10 in weekday/weekend were 8.1% and 7.6%, 0.37% and 0.41%, respectively. This research will help understand chemical composition of water-soluble ions during the weekday/weekend and will be able to measure the contribution level of artificial anthropogenic source on urban air.

• 한국대기환경학회지
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• 제23권1호
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• pp.74-83
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• 2007

Artifacts due to inter-particle and gas-particle interactions during PM2.5 sampling were quantified by comparing the measurement results between the annular denuder-filterpack system and the filterpack system without denuder. Measurements were carried in Seoul for 10 days in each season; Nov. 2004, Jan. 2005, Mar. 2005, and Jul. 2005, respectively. In each day, two 12-h samples were obtained. The concentrations of nitrate and chloride showed seasonal variations mainly due to the availability of ammonium to neutralize nitrate or chloride. Nitrates and chloride losses were prominent in summer. Since most of ammonia was used to neutralize sulfuric acid and formed ammonium sulfate in summer, nitrate and chloride could not exist in particles and ammonium loss was smaller than other seasons.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.417-418
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• 2009

해안 및 매립지 구조물은 염화물의 침투로 인해 매입된 철근의 피막파괴로 철근부식이 일어나 콘크리트 구조체에 열화가 급속하게 진행되기 때문에 앞으로의 해안 구조물의 수밀성, 내염해성을 필요로 한다. 따라서 본 연구에서는 내염해성 개선에 효과적인 액상형태의 Si/Al 복합 무기염을 모르타르에 적용하여 시간경과(7, 14, 28, 56일)에 따른 내염해특성을 파악하고자 하였다.

• The Korean Journal of Ceramics
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• 제4권3호
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• pp.183-188
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• 1998

Gas sensitizations of tin oxide film were investigated by measuring the change of film resistance in various gas atmospheres such as $N_2,\; O_2,\; H_2O$. The main test sample, polycrystalline $SnO_2$ film containing small Sb as a dopant was prepared by a sputtering technique and showed a long term stability in base resistance and thus, in gas sensitivity. The adsorption of oxygen on the film surface as a type of $(O_{ads})$ at the temperature of around $300^{\circ}C$ played important roles in sensor operating mechanism. The roles were ⅰ) the increase of base resistance in ambient air, which consequently lead to high sensitivity and ⅱ) the promotion of fast recovery. The reaction of hydrogen gas with the already adsorbed $(O_{ads})$ ions was considered as a decisive sensitization mechanism of tin oxide film. However, the dissociation of hydrogen molecules on film surface, by direct donation of electron to film also took a major part in the sensitization. The effect of humidity on gas sensitization was found to be negligible at the sensor operating temperature of around $300^{\circ}C$.

• 한국자원식물학회지
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• 제28권4호
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• pp.533-540
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• 2015

Germination properties, leachate electrical conductivity (EC), and inorganic compound leaching were analyzed to ascertain the storage ability and change of physiological characteristics during storage of Hippophae rhamnoides seeds. Seeds were placed in an incubator at 25℃ and sown in different soil media (sand, vermiculite and horticultural substrate) after being stored for 6, 18 and 30 months at 2℃. All germination properties decreased in accordance to an increase of the seed storage period. Compared with the seed storage for 18 months, germination percentage (GP), germination performance index (GPI), and germination value (GV) of seeds stored for 30 months decreased by more than 50%. When the seeds were sown in different soil media in a greenhouse, those germination properties were similar to the seeds germinated in an incubator, and mean germination time, GPI and GV had a significant difference except GP among soil media. EC and inorganic ion concentration had a strong positive correlation with the seed storage period, but the ratios of inorganic ions from stored seeds revealed that K⁺/Mg²⁺ and Na⁺/Mg²⁺ were inversely correlated with the storage period.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1385-1390
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• 2006

Concrete structure can be deteriorated by ingress of moisture and aggressive agents. To maintain the sound performance of concrete structure during the service life, it needs to protect concrete from ingress of moisture and aggressive agents before arising deterioration of concrete. Protection of concrete is possible by surface treatment. In this study, durability of the functional nano composite inorganic activated carbon based coatings which can provide a barrier against the ingress of moisture or aggressive ions to concrete is discussed. For the durability evaluation of the coatings, fine void structure evaluation test, chloride penetration acceleration test, accelerated carbonation test, freezing and thawing test, and the accelerated test of chemical erosion are conducted. As the result of this study, the functional nano composite inorganic activated carbon based coatings which became one formed complex compound with adsorption and porosity on concrete surface, had an effect on the function of far infrared radiation, antimicrobial action, air cleaning, airing assurance, and the interception of moisture of deterioration factor, chloride ion, carbon dioxide, sulfate, and so on.

• 생물환경조절학회지
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• 제10권2호
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• pp.125-131
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• 2001

순환식 펄라이트 재배에서 오이의 양액흡수는 일사량 변화와 관계없이 단위일사량당 흡수량이 80~100 mg.MJ$^{-1}$까지 증가 후 일정하게 유지되어 양액흡수 지표는 전체 양액흡수량보다 단위일사량당 양액흡수량이 더 적합하였다. NO￣$_3$-N의 흡수량은 초기에 3 mg.MJ$^{-1}$에서 후기 16 mg.MJ$^{-1}$로 상승하였고 Ca는 초기에 3mg.MJ$^{-1}$에서 후기에 14 mg.MJ$^{-11}$ 로, Mg는 초기에 1 mg.MJ$^{-1}$에서 후기에 5 mg.MJ$^{-1}$로 증가되었으나, 정식 후 62일 이후의 증가세로 둔화되었다. K는 초기에 5.0 mg.MJ$^{-1}$에서 후기 18 mg.MJ$^{-1}$로 증가되었으나 지속적인 증가를 보여주지 못하였는데 이것은 오이의 하엽 제거로 인한 결과로 생각되어진다. 그러나 P는 초기에 0.5 mg.MJ$^{-1}$에서 후기의 3.2mg.MJ$^{-1}$로 지속적으로 증가되었다. S는 초기에 0.5 mg.MJ$^{-1}$에서 증가에 6.5 mg.MJ$^{-1}$까지 증가되다가 후기에 2.7 mg.MJ$^{-1}$로 감소되었다. 오이의 각각의 무기이온 흡수량과 가장 상관이 높았던 요소는 정식일수와 엽면적이었으나 이 두 요소와 단위일사량당 양액흡수량과는 $r^2$=0.92, 0.97로 높은 상관을 보였다. 단위일사량당 양액흡수량을 이용한 각각의 무기이온 흡수량 회귀식은 $r^2$=0.9 이상으로 높은 상관관계를 보여 실용적 이용이 가능할 것으로 보였다.