• 제목/요약/키워드: Chemical stability difference

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Interaction of the Post-transition Metal Ions and New Macrocycles in Solution

  • Jung, Oh-Jin
    • Bulletin of the Korean Chemical Society
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    • v.14 no.6
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    • pp.687-691
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    • 1993
  • Complexation of $Cd^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions with four cryptands were studied by potentiometry and solution calorimetry in various weight percent methanol-aqueous solvent at 25${\circ}$C under $CO_2$free nitrogen atmosphere. The stabilities of the complexes were dependent on the cavity size of macrocycles. The $Hg^{2+}$ ion stability constants are higher than those of $Cd^{2+}\;and\;Pb^{2+}$ ion. All the cryptands formed complexes having 1 : 1 (metal to ligand) mole-ratio except for $Hg^{2+}-L_1$ (cryptand 1,2b: 3,5-benzo-9,14,17-trioxa-1,7-diazabicyclo-(8,5,5) heptadecane) and $Cd^{2+}-L_2$ (cryptand 2,2b: 3,5-benzo-10,13,18,21-tetraoxa-1,7-diazabicyclo (8,5,5) eicosane) complexes. $Hg^{2+}-L_1$ complex was a sandwitch type, and the $Cd^{2+}-L_2$ complex showed two stepwise reactions. Thermodynamic parameters of the $Cd^{2+}-L_2$ complex were $6.08(log\;K_1)$, -7.28 Kcal/mol $({\Delta}H_1)$, and $4.78\;(log\;K_2)$, -4.62 Kcal/mol $({\Delta}H_2)$, respectively, for 1 : 1 and 2: 1 mole-ratio. The sequences of the selectivity were increased in the order of $Hg^{2+}\;>Pb^{2+}\;>Cd^{2+}$ ion for $L_3\;and\;L_4$ macrocycles, and the $L_2$-macrocycle has a selectivity for $Cd^{2+}$ ion relative to $Zn^{2+},\;Ni^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions. Thus, it is expected that the $L_2$ can be used as carrier for seperation of the post transition metals by macrocycles-mediated liquid membrane because $L_2$ is not soluble in water, and the difference of stability constants of the metal complexes with $L_2$ are large as compared with the other transition metal complexes. The $^1H\;and\;^{13}C-NMR studies indicated that the nitrogen atoms of cryptands have greater affinity to the post transition metal ions than the oxygen atoms, and that the planarities of the macrocycles were lost by complexation with the metal ions because of the perturbation of ring current of benzene molecule attached to macrocycles and counter-anions.

Studies on the Surface Charge Characteristics of Two Inceptisols and One Aridsol in Hawaii (하와이 화산회(火山灰)로부터 발달한 Inceptisols과 Aridsol 토양(土壤)의 표면전하(表面電荷) 특성(特性)에 관(關)하여)

  • Lim, Sookil H.
    • Korean Journal of Soil Science and Fertilizer
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    • v.14 no.3
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    • pp.110-116
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    • 1981
  • Soil surface charge which manipulates some important soil physico-chemical properties such as nutrient and water holding abilities, colloidal stability and soil erosion was investigated in wide range of soil pH, using soils developed originally from same volcanic ash deposit but under different rainfall condition in Hawaii. The results can be summarized as follows : 1. Ustollic Camorthid (Kawaihae soil) which was developed under the lowest rainfall (less than 500 mm/yr) revealed low Z.P.C. (4.5-5.0) and less dependence of net charge on concentration of indifferent electrolytes. 2. Typic Hydrandepts (Akaka and Hilo soils) which were developed under the high rainfall (3050-7600 mm/yr) showed the Z.P.C. in between 5.5-7.0 and high dependence of net charge on concentration of indifferent electroytes. 3. It was found by X-ray diffraction together with total chemical analysis that amorphous materials were dominant (above 6.0%) in Typic Hydrandepts while dehydrated halloy-site (1 : 1 clay minerals) was dominant (45-50%) in Ustollic Camorthid. 4. In spite of little difference in particle size distribution of the soils, the difference of specific surface area was remarkable showing the order of Akaka (289) > Hilo (268) > Kawaihae (93). 5. It was evident, taking account of apparent field pH values, 5.2 of Akaka, 5.5 of Hilo and 7.0 of Kawaihae soil, respectively, that Akaka, and Hilo soils would show either positive or near zero (+ or 0) of ${\Delta}pH$ while Kawaihae soil would exhibit negative (-) of ${\Delta}pH$ at natural field condition.

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Preparation and Properties of Moisture-absorbing Film Impregnated with Polyacrylic Acid Partial Sodium Salt Material (폴리아크릴산 나트륨 염이 함침된 흡수성 고분자 복합 필름의 제조 및 특성 연구)

  • Lee, Youn Suk;Choi, Hong Yeol;Park, Insik
    • Korean Chemical Engineering Research
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    • v.52 no.4
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    • pp.530-537
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    • 2014
  • Moisture is a major factor causing the deteriorative physical change, microbial growth, and chemical reaction of the products. In this study, the moisture absorbing composite films have been prepared with moisture absorbing material of polyacrylic acid partial sodium salt (PAPSS) impregnated on LLDPE polymer for the functional packaging applications. The results showed that PAPSS impregnated film illustrated uniformly dispersed PAPSS particles in the LLDPE polymer matrix. The transparency of the PAPSS impregnated film decreased slightly at higher PAPSS concentrations. An increase in the PAPSS content for moisture-absorbing films showed a similar decrease in tensile strength, percent elongation at break, and tear strength. Their values of films impregnated with PAPSS of 0.5, 1, and 2% showed no significant difference. Meanwhile, 4% PAPSS films significantly decreased the values of mechanical properties compared to the films impregnated with different PAPSS levels. Values of the oxygen permeability and water vapor permeability for PAPSS impregnated films decreased significantly with greater PAPSS. The results indicate that 4% PAPSS impregnated in LLDPE films had high affinity of moisture absorbencies compared to the other films. The mathematical equation that best described the moisture sorption isotherm of each film sample was the GAB equation at $25^{\circ}C$. The crystallization and melting temperatures of PAPSS films were influenced by the addition of PAPSS material, but showed good thermal stability.

Availability Evaluation of TOC as the Environmental Standard - Survey of Lakes in Nakdong River Basin - (환경기준으로서의 TOC에 대한 활용성 평가 - 낙동강수계 호소를 대상으로 -)

  • Choi, Byoungwoo;Kang, Meea
    • Journal of Wetlands Research
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    • v.20 no.2
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    • pp.173-180
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    • 2018
  • The utilization of TOC(Total organic carbon), a new environmental standard, was evaluated for 30 lakes in the Nakdong River Basin, which is used for drinking and agricultural usage. The active use of water resources begins with securing satisfactory water quality. Since this allows people and nature to maintain stability of quality, water quality standards are being tightened to ensure good water quality. In order to improve the pollution level of organic matter in lakes in the living environment, it is important to use the appropriate organic substance index. The relationship between the newly introduced TOC and the existing COD(Chemical oxygen demand) in the targeted lake was positively correlated with the possibility of replacing the TOC with COD. However, the environmental grade standard using TOC is better than the environmental grade standard using COD, so it has the same effect as that of the grade of water quality using TOC as an organic substance factor. This indicates the limitation of TOC to directly replace existing COD when trying to determine or improve the quality level using organic indicators of lakes. Therefore, in order to secure the qualitative safety of the lake, it is required to strengthen environmental standards of TOC in terms of water quality grade. In addition, the correlation between TOC and COD shows a great difference depending on the utilization characteristics of the lake. This requires clear scientific identification, and it requires continuous monitoring of COD that has been used to accumulate indicators of lake organic matter.

Effects of a Dye from Artemisia, the Natural Dyeing Material, on the Functionality of Dyeing in Mind-Peace Education for the Silver Generation (실버세대 감성교육을 위한 천연염재 쑥속(Artemisia)식물의 염료가 염색의 기능성에 미치는 영향)

  • Lee, Jung-Eun;Kwon, Young-Suk
    • Journal of Environmental Science International
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    • v.24 no.5
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    • pp.633-639
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    • 2015
  • The experience of natural dyeing is expected to be effective in promoting health through good exercise, in giving emotional stability based on the functional aromatic components of the dyeing material, and in improving self-esteem and increasing positive experiences through the behavior of creation. A natural dyeing material easily found around us, artemisia has long been used in food and Oriental medicine and was recently found to contain antioxidative, anticancer, deodorizing, antibacterial, anti-obesity, and anti-diabetes substances through chemical analysis. It has also been reported that group reminiscence therapy using the fragrance of artemisia is effective in relieving pain and depression and in promoting ego integrity in the elderly population. This study aimed to make a comparative analysis of dyeability, washing fastness, and deodorization between Artemisia princeps, Artemisia iwayomogi, and Artemisia annua, all of which are considered to be healthful and functional dyeing materials, among about thirty domestic plants in the genus of Artemisia and to provide basic data concerning natural dyeing in mind-peace education for the silver generation. The fabric dyed and post-mordanted at $80^{\circ}C$ for 40 minutes showed the greatest surface color variation; in this condition, artemisia princes (32.29) gave the greatest color difference, followed by artemisia iwayomogi (31.07) and artemisia annua (26.17). While all the types of artemisia were excellent in washing fastness, dry-cleaning fastness, and rubbing fastness at the fourth- or fifth-grade, light fastness was at the third grade for artemisia princes, at the second to third grade for artemisia annua, and at the second grade for artemisia iwayomogi; therefore, artemisia princes was found to give better fastness than the other two types of artemisia. In determining functionality of the fabric dyed with artemisia, deodorization test also found that the fabric dyed with artemisia princes had 20% higher deodorization.

Effect of wheat bran and dried carrot pomace addition on quality characteristics of chicken sausage

  • Yadav, Sanjay;Pathera, Ashok K.;Islam, Rayees Ul;Malik, Ashok K.;Sharma, Diwakar P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.5
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    • pp.729-737
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    • 2018
  • Objective: Effect of addition of wheat bran (WB) and dried carrot pomace (DCP) on sensory, textural, colour, physico-chemical and nutritional characteristics of chicken sausage were evaluated. Methods: WB and DCP were used as a source of dietary fibre at 3%, 6%, and 9% level individually. Different quality attributes of sausages were estimated. One product from each source with very good sensory acceptability was selected to analyze dietary fibre content and shelf life under refrigerated storage. Results: Sensory acceptability of 3% fibre enriched sausage was comparable with control and a further increase in fibre level resulted in a decrease in sensory acceptability. Fibre enriched sausages were significantly harder and less cohesive than control sausage. Significant increase in gumminess and chewiness was observed at 6% level in WB treated sausages and 9% level in DCP treated sausages. Moisture content decreased significantly in all treated sausages, protein content decreased significantly in DCP-2 and DCP-3 sausages while fat content decreased in all WB and DCP-3 treated sausages in comparison to control. The fibre enriched sausage had significantly higher dietary fibre and lower cholesterol content. Cooking yield and emulsion stability increased in treated sausages and a significant difference was noticed at 6% level in both types of sausages. pH of WB treated sausages was significantly higher and DCP treated sausage significantly lower in comparison to control. Conclusion: The results of present study indicate that fibre enriched chicken sausage with moderate acceptability can be developed by incorporating WB and DCP each up to 9% level. Chicken sausage with very good acceptability, higher dietary fibre content and storability up to 15 days at refrigerated temperature can be developed by incorporating WB and DCP at 6% level each.

Effects of Dietary Proteins and Inositol Hexaphosphate on the Preneoplastic Lesions and Antioxidant Enzymes of Hepatocellular Carcinogenesis in Rats (식이 단백질의 종류 및 Inositol Hexaphosphate가 간세포 암화과정에서 전암성 병변의 지표 및 항산화 효소계에 미치는 영향)

  • 김현덕;최혜미
    • Korean Journal of Community Nutrition
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    • v.4 no.2
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    • pp.239-247
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    • 1999
  • Six-week-old Sprague Dawley rats were fed the diets of 20% casein or soy protein. Two weeks after the feeding, hepatocellular chemical carcinogenesis was initiated by diethylnitrosamine(DEN), and promoted by the diet containing 0.01% 2-acetylamino-fluorene(AAF) and two-thirds partial hepatectomy(PH). The animals were sacrificed at 8 weeks after the DEN injection. The area of placetal glutathione S-trnasferase(GST-P) positive foci, the activities of several enzymes in cellualr antioxidant enzyme systems and glucose 6-phosphatase were determined to investigate the mechanism of the anticarcinogenic effect by the dietary proteins. In another set of experiments, the drinking water of rats fed casein was supplemented with 1.5% inositol hexaphosphate(InsP6) to elucidate whether it has the comparable anticancer action of soy protein. The area and number of GST-P positive foci in the soy protein group were significantly(p<0.05) lower than those inthe casein group. The livers of rats fed casein showed moderate fattydegeneration and larger hyperplastic nodules than those of rats fed soy protein. In another set of experiments, the area and number of GST-P positive foci in the rats fed casein supplemented with InsP6 were not significantly different from those in the rats fed casein or soy protein. The lipid peroxidation of rats fed different protein sources showed no significant difference. Glutathione S-transferase(GST) activities were increased significantly(p<0.05) by carcinogen treatment in all dietary groups. Glucose 6-phosphatase(G6Pase) activities were decreased by carcinogen treatment, and hence showed a reverse relationship(r=-0.695, p<0.01) to the GST-P positive foci. Therefore, the activities in the rats fed casein were lower than those in the rats fed soy protein. These results suggest that the soy protein seems to be more anti-carcinogenic than casein by decreasing the preneoplastic lesion and by increasing the membrane stability but inositol hexaphosphate, a component of soy protein, may not be protective against hepatocarcinogenesis.

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Isolation and Purification of Resveratrol from a Grape Twig (포도 송이가지에서 레스베라트롤의 분리 정제)

  • Shin, Hyun-Jae;Kang, Byung-Sun;Ahn, Jun-Bae;Kim, Bok-Hee
    • KSBB Journal
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    • v.22 no.5
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    • pp.351-355
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    • 2007
  • Resveratrol, a polyphenolic compound with antioxidative property, was purified from the grape's twig to be used as functional additives of food and/or cosmetics. Extraction of the grape's twig was performed using 80% ethanol in ultrasonic extractor for 60 min. The crude extract was purified up to 99% after elution through silica gel open column chromatography. The stability of the purified resveratrol was as follows: a half life of 90 days at 40$^{\circ}C$ and 60 days at 25$^{\circ}C$. A sensory test of the commercial grape juice including the 1-10 ppm of purified resveratrol showed better preference than the grape juice without purified resveratrol additive. Color and smell test showed no difference between the samples. The grape twig can be used as a valuable resource for the extraction of resveratrol, which would be added to nutraceutical and cosmetic products.

A Study on the Viability of Human Dermal Fibroblast Cell by Media for Ni-Cr alloy elution (치과용 Ni-Cr합금 용출배지에 의한 인간 피부 섬유아세포 성장도 관찰 연구)

  • Kim, Kap-Jin;Choi, Sung-Min;Kim, Chi-Young
    • Journal of Technologic Dentistry
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    • v.31 no.3
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    • pp.21-26
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    • 2009
  • Purpose: Standards of alloy for porcelain fused to metal crown be classified by metallic factor and biological factor. Metallic factors consist of stability of alloy composition and mechanical strength and surface characteristics for chemical bond. Biological factors be considered properties of metallic elements and problems originated by toxicity and hypersensitive reaction. Alloys considered such controversial points are the most suitable alloy for dental instrument. Method: Alloys added Be and Nb using Ni-Cr alloy which has been widely used for dental instrument be selected and classified experimental group. Non-addition Be and Nb to Ni-Cr alloy classify control group and addition Be alloy is Be-experimental group, addition Nb alloy is Nb-experimental group. Specimens for cytotoxicity analysis gave effect to washing and sterilization. and then made an experiment on elution with cell medium after disinfection. It conducted specimens within cell medium with 24hours, 48hours, 72hours, respectively. It cultured human dermal fibroblast(HDF) using cell medium for cytotoxicity test and then investigated elution rate through spectroscopic analysis by MTT-assay. Result: As results of cytotoxicity test by MTT-assay, cultured cell rate of VII measured more low numerical value within elution medium for 24hours focused on control group. Also, cultured cell rate of K3 alloys observed low value for 48hours, 72hours than value of control group. Conclusion: According to final result that synthesize above results, Ni-Cr alloy added Be and Ni has little difference in Cytotoxicity by MTT-assay.

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A Study on the Cleaning Efficiency using the d-Limonene Oil Extracted in Wasted Mandarin Peels (폐감률피에서 추출한 limonene 오일의 세정성에 관한 연구)

  • Song, Min-Kyung;Oh, Eun-Ha;Im, Ho-Sub;Kim, Yoon-Shin
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.2
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    • pp.107-113
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    • 2010
  • The object of this research is to conform of practicable possibility and recycling of producing junk after citrus fruits is processed. With extracting d-limonene oil that have 70~90% a component of oil out of junk citrus peel, making certain the about 12000ppm concentration of it. Limonene derived from citrus in jeju using conventional synthetic detergents can be replaced with the development of environmentally friendly natural detergent investigated the possibility. Mostly due to ocean dumping, disposal and cause environmental problems by recycling natural citrus cleaner alternative to the research conducted on the possibility. Cleaning efficiency with temperature did not affect the largest concentrations were able to identify the difference between cleaning efficiency. At least 10% of the d-limonene oil could be from the cleaning performance, increasing the concentration of the cleaning efficiency was increased in size. Ultrasonic is very high removal efficiency under the conditions shown in the cause of pure self-generated ultrasonic cleaning power as co-effects of d-limonene oil appears to chemical cleaning effect of ultrasonic cavitation occurs in the physical cleaning effect due to a combination of synergistic stability is maximized by low concentrations of d-limonene oil in a short time showed an excellent cleaning ability. Having the ability of cleaning at the same time, considering the side recycling in the junk citrus peels reflects possibility of basic materials utility eco-friendly in the skin soap, bath soap, cosmetics etc, through ability of exclusion a contaminant in based cleaning effect(EC) it can prospect substitution effect environmentally in the pre existence synthetic detergents.