• Journal of Ecology and Environment
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• 제30권2호
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• pp.187-193
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• 2007

Higher plants can be categorized as C3, C4 or CAM according to their photosynthetic pathways, and some succulent plants are known to shift their patterns of photosynthesis from C3 to CAM in response to environmental stresses such as salt treatment or water deficiency. To investigate fundamental photosynthetic patterns and the induction of pattern shifts (C3, CAM, C3-CAM etc.) as a result of environmental stresses, we measured the water content, diurnal changes in pH, net $CO_2$ exchange, transpiration rate, total ionic contents, and osmolality of Kalancoe daigremontiana, Sedum kamschaticum and Sedum sarmentosum which belong to Crassulaceae known as representative CAM plant, after 10 days of drought treatment. S. kamschaticum and S. sarmentosum did not show a significant difference in diurnal pH variation in the treatment and control conditions. However, the pH of drought-treated Kalancoe was low at night and high in the daytime, with a pH value between 4 and 5. Typical CAM plants display a net $CO_2$ exchange that increases at night and decreases in the daytime. Kalancoe displayed the predicted pattern. However, S. kamschaticum and S. sarmentosum showed a photosynthetic pattern more typical of C3 plants, and did not show changes in photosynthetic pattern under drought stress. Kalancoe also showed a transpiration rate typical for CAM pho-tosynthesis, whereas the transpiration rates of S. kamschaticum and S. sarmentosum were in the typical range for C3 photosynthesis. Kalancoe had high total ionic contents during the night, which decreased somewhat during the daytime, whereas S. kamschaticum and S. sarmentosum displayed the opposite pattern. This result is similar to the diurnal patterns of changes in pH in the three plant species, which suggests a relationship between pH and ionic contents. S. sarmentosum showed lower osmolality under drought stress than in the control condition, whereas the osmolality of Kalancoe and S. kamschaticum did not differ between conditions. S. sarmentosum may have maintained internal water content by lowering its osmolality and raising its total ionic contents. In conclusion, Kalancoe displayed the characteristic responses of a typical CAM plant, whereas S. kamschaticum and S. sarmentosum displayed aspects of the C3 photosynthetic pattern under drought conditions. These results suggest that S. kamschaticum and S. sarmentosum (Crassulacea) in Korea overcome drought stress by increasing solute and ionic contents internally rather than changing their photosynthetic pattern from C3 to CAM under drought stress.

• Journal of Nutrition and Health
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• 제11권3호
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• pp.37-42
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• 1978

Actomyosin and myofibril were extracted from Korean native Goat muscle with the Weber-Edsall solution. ATPase activities and physiochemical properties were measured. The results obtained were as follows; 1) Mg-activitied ATPase activity of actomyosin and myofibrill from Korean native Goat muscle exhibited a common biphasic response, a typical ATPase pattern, that is high at a low ionic strength and low at a high ionic strength. Actomyosin showed high activity than myofibrill. 2) Mg-activited ATPase activity of actomyosin from muscle increased extraction time 24 hours. 3) EDTA-enhanced ATPase activity of actomyosin was greater than myofibrill and low at the low ionic strength, high at the high ionic strength. The difference of the activity were shown great broad pattern at the after 0.3M KCI concentration. 4) Effect of EGTA on-ATPase activity of myofibrill and actomyosin from muscle was measured, the Mg-ATPase activity was markedly depressed. 5) Solubility of actomyosin from muscle began to solubilize at KCI concentration of 0.28M and solubilized completely at the KCI concentration of 0.3M.

• 폴리머
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• 제32권5호
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• pp.409-414
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• 2008

전기방사법으로 이온염을 함유하는 TFE/증류수 혼합용매를 이용하여 젤라틴 나노섬유를 제조하였으며, 얻어진 나노섬유의 평균직경은 $110{\sim}125\;nm$였다. 이온염의 농도가 증가할수록 비드의 발생이 줄어들고 균일한 나노섬유 제조가 가능하였다. 이는 이온염의 첨가에 의한 젤라틴 용액의 점도 및 전도도가 증가함에 기인하는 것으로 확인되었다. 특히 일가이온보다 이가이온을 사용할 경우 점도 및 전도도의 증가에 더 효과적이었으며 이들 이온염은 분자간 소수성 상호작용뿐만 아니라 젤라틴 분자의 입체구조 정렬에도 영향을 주었다. 그러나 이온염 농도에 따른 나노섬유의 직경변화는 관찰되지 않았다. 제조된 나노섬유를 이용한 XRD분석 결과 이온염의 농도가 증가할수록 젤라틴 분자의 재결정화에 의해 나노섬유의 결정화도가 높아졌다.

• Journal of Pharmaceutical Investigation
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• 제19권4호
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• pp.179-183
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• 1989

Drug release experiments were performed based on pH-sensitive swelling behaviors of polymethacrylic acid. 5-Fluorouracil as a nonionic model drug revealed release patterns depending solely on pH-dependent swelling kinetics of polymethacrylic acid. In contrast, release of propranolol hydrochloride as a cationic model drug was significantly affected by ionic drug-polymer interaction as well as the swelling kinetics. Accordingly, a zero-order release pattern was obtained at pH 7, which was distinguished from the general matrix type drug release pattern.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.379-381
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• 1994

Volume holograms recorded in photorefractive materials can find important applications in optical memories and optical computing systems. One problem with a photorefractive hologram is that it gets erased by the readout light. Nondestructive readout can be achieved by hologram fixing, and several fixing methods have been reported. Fixing is accomplished by thermally activated motion of an unknown ionic defect, which neutralizes the electronic space-charge patterns. At room temperature the ionic patterns are stabilized. When the electrons are partially redistributed by light, a net space-charge pattern appears, and tile fixed hologram can be read out. In this paper, theoretical modeling and some experimental results are presented for thermal fixing of volume phase holograms in photorefractive $LiNbO_3$:Fe. Thermal fixing can be done during or after recording and depends on fixing temperature ($100{\sim}200^{\circ}C$ range) and grating length. Fixed Slating can be erased completely at the temperature over $300^{\circ}C$. Theoretical modeling shows weil the compensation of electronic Slating by ionic grating and is in good agreement with experimental results. In experiments the dependence of thermal fixing on temperatures and grating lengths is investigated.

• 한국대기환경학회지
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• 제26권4호
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• pp.420-431
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• 2010

The water-soluble components have been analyzed from the total suspended particulate (TSP) collected at Gosan site of Jeju Island for ten years (1997~2006), and the long-term variations of ionic constituent concentrations have been investigated in order to understand the pollution characteristics of atmospheric aerosols. Their mean concentrations were in the order of nss-${SO_4}^{2-}$ > $Na^+$ > ${NO_3}^-$ > $Cl^$ > ${NH_4}^+$ > nss-$Ca^{2+}$ > $K^+$ > $Mg^{2+}$. The ${NO_3}^-$ concentrations had increased somewhat smoothly compared to those of ${SO_4}^{2-}$ for the past 10 years, possibly indicating the recent energy consumption pattern changes in China. The concentrations of ionic aerosol components showed mostly higher values during the Asian Dust storm periods, and the concentration ratios of nss-$Ca^{2+}$, ${NO_3}^-$, and nss-${SO_4}^{2-}$ between the Asian Dust and Non-Asian Dust periods were 6.9, 2.4, and 1.3, respectively. The anthropogenic nss-${SO_4}^{2-}$, ${NO_3}^-$, ${NH_4}^+$ and the soil originated nss-$Ca^{2+}$ components showed high concentrations as the air parcels were moved from the Asia continent, on the other hand, their concentrations were relatively low as moving from the Northern Pacific into the Gosan area.

• Journal of Magnetics
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• 제7권2호
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• pp.25-28
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• 2002

Slowly cooled $Cu_xFe_{3-x}O_4$ ($\chi$=0.1, 0.2) have been investigated over a temperature range from 82 to 700 K using the M$\ddot{o}$ssbauer technique. X-ray diffraction shows that these have a single-phase cubic spinel structure of lattice parameters $\alpha$=8.396 and 8.398${\AA}$, respectively. Since Cu ions prefer B (octahedral) sites to A (tetrahedral) sites, the ionic distribution is $(Fe)_A[Fe_{2-x}Cu_x]_BO_4$. M$\ddot{o}$ssbauer spectra consisted of two sets of 6-line pattern from. A site in ferric state and B site in ferrous-ferric state. Intensity ratio of B to A subspectra is 1.0 at 82 K and increases to 2.0 at 700 K with increasing temperature. After annealing the samples under vacuum at $450^circ{C}$ for a half hour, x-ray diffraction patterns have the peaks of magnetite- and hematite-phase. Lattice constants of magnetite-phase are 8.395 and 8.392 ${\AA}$ smaller than 8.396 and 8.398 ${\AA}$ before annealing, respectively. M$\ddot{o}$ssbauer spectra reveal the conventional magnetite pattern with the additional hematite pattern. Intensity ratios of B to A subspectra fur magnetite-phase become 1.9-2.0 over all temperature ranges and Cu ions are distributed over A and B sites randomly. Ratios of hematite to total intensity in M$\ddot{o}$ssbauer spectra for $\chi$= 0.1 and $\chi$= 0.2 are 10 and 21%, respectively. These hematite ratios may be due to annealing under vacuum at $450^circ{C}$, which transforms $Cu^{2+}$ ionic states into $Cu^{1+}$. Verwey temperatures far $\chi$= 0.1 and $\chi$= 0.2 are $123\pm2$ K and $128\pm2$ K.

• 한국식품과학회지
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• 제30권1호
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• pp.69-76
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• 1998

본 연구는 재구성육제품내 첨가제를 줄이는데 있어 예비혼합물에 첨가제를 전량 첨가하여 그 기능적 특성을 최대한 부여시킬 수 있는 첨가제의 종류와 이온강도 효과의 조건을 설정하고자 실시하였다. 육제품의 10%를 예비혼합들로 설정하여 돼지전지부위에 NaCl(0, 4.5, 9.0%), STPP (0, 2.5, 5.0%), PP (0, 2.44, 4.88%)를 각각 세단계로 이온강도를 같게 설정한 후 조합첨가하여 27가지 예비혼합물을 제조하고 pH와 추출한 단백질의 기능적 특성을 조사하였다. pH는 STPP와 PP의 첨가에 의해 증가하는 경향을 나타냈으며(p<0.01), 동일 이온강도에서 PP가 STPP에 비해 높은 pH증진효과를 보였다. 예비혼합물에서 추출한 단백질(1 M NaCl, 동일한 염추출 용액 사용)의 특성 중 총 단백질추출성에 대하여 동일 이온강도 하에서 phosphate 이온이 chloride 이온보다 추출효과가 뛰어났다. 단백질의 용해성은 NaCl 첨가로 용해성이 낮아졌으며(p<0.05), 단백질추출성이 좋을수록 용해성이 감소하는 것으로 나타났다. 원료육 내의 SH기 함량은 단백질추출성이 좋은 경우 SH기 함량이 높은 경향을 보였다. 단백질의 가열처리를 가상한 $65^{\circ}C$, 7분간의 단백질 추출물의 열처리 효과로 원료육의 SH기 함량이 낮아지고 소수성은 증가하였다(p<0.1). 그러나 세 첨가제에 의한 27가지의 예비혼합물에서 추출한 단백질의 전기영동상 형태는 차이가 나타나지 않았다. 결론적으로 첨가제의 조합에 의해 이온강도가 높아짐에 따라 기능적 특성이 증가되지는 않았으나 인산염 중 동일이온강도를 감안할 때 첨가제를 줄이는 방안으로는 STPP보다 PP가 좋은 것으로 판단되었다.

• 공업화학
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• 제8권4호
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• pp.575-581
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• 1997

두 종류의 폴리올(PTMG, PBEAG), 이온성 쇄연장제(DMPA), $H_{12}-MDI$ 및 EDA를 이용하여 폴리우레탄 수분산체(PUD)를 합성하였다. PU/PMMA hybrid는 PUD를 MMA 단량체로 팽윤 시킨 후 라디칼중합으로 제조하였다. 이온기에 따른 PUD의 입자 크기 및 필름 물성을 검토하였으며, MMA 함량에 따른 hybrid의 기계적, 열전 성질을 검토하였다. PUD내 dimethylol propionic acid(DMPA)의 함량을 2, 4, 6, 8, 10wt%까지 증가시켰을 때 유화 입경이 감소하였으며, 또한 에테르형 폴리올보다 에스터형 폴리올을 사용한 PUD의 유화 입경이 작았다. 필름 물성에 있어 이온기의 함량이 증가함에 따라 상분리도가 증가하는 것을 열적, 기계적 분석을 통해서 확인할 수 있었다. PU/PMMA hybrids에서 MMA의 함량이 증가함에도 PUD의 팽윤에 의한 유화 입경의 증가는 크지 않았다. PU의 에스터형은 DMPA의 함량이 6wt%까지, 에테르형 폴리올을 썼을 경우 DMPA 함량이 4wt%까지 기계적 강도가 MMA 단량체의 함량이 증가함에 따라 높아졌고, DSC분석에서 $T_g$는 상승하고 완만해지는 것을 확인하여 hybrid가 분자 수준의 혼합이 이루어지고 있음을 알 수 있었다.

• 한국환경과학회지
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• 제27권4호
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• pp.241-250
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• 2018

The objective of this study was to estimate air quality trends in the study area by surveying monthly and seasonal concentration trends. To do this, the mass concentration of $PM_{10}$ samples and the metals, ions, and total carbon in the $PM_{10}$ were analyzed. The mean concentration of $PM_{10}$ was $33.9{\mu}g/m^3$. The composition of $PM_{10}$ was 39.2% ionic species, 5.1% metallic species, and 26.6% carbonic species (EC and OC). Ionic species, especially sulfate, ammonium, and nitrate, were the most abundant in the $PM_{10}$ and had a high correlation coefficient with $PM_{10}$. Seasonal variation of $PM_{10}$ showed a similar pattern to those of ionic and metallic species. with high concentration during the winter and spring seasons. $PM_{10}$ showed high correlation with the ionic species $NO_3{^-}$ and $NH_4{^+}$. In addition, $NH_4{^+}$ was highly correlated with $SO{_4}^{2-}$ and $NO_3{^-}$. We obtained four factors through factor analysis and determined the pollution sources using the United States Environmental Protection Agency(U.S. EPA) pollution profile. The first factor accounted for 51.1% of $PM_{10}$ from complex sources, that is, soil, motor vehicles, and secondary particles: the second factor indicated marine sources; the third factor, industry-related sources; and the last factor, heating-related sources. However, the pollution profile used in this study may be somewhat different from the actual situation in Korea because it was from US EPA. Therefore, to more accurately estimate the pollutants present, it is necessary to create a pollution profile for Korea.