• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.275-275
• /
• 2007

Two sorts of electrode composed of Sulpur/CNT/PVDF and Silver/CNT/PVDF were prepared by in situ chemical method and their electrochemical performance were evaluated by using cyclic voltammetry, impedance measurement and constant-current charge/discharge cycling technique. Also, composite electrodes were characterized by FE-SEM and BET. Raw materials such as CNT/Silver and CNT/Sulfur were mixed in ethanol, dried. These mixed materials were heated at 900 and $320^{\circ}C$ for 2hr, respectively in order to enhance contact among CNT electrodes. Electric double layer capacitor cells were fabricated using these mixed powder with polymer of PVDF. For the charging and discharging characteristics measured at scan rate of 1 mA/s, Supercapacitor of Sulphur-CNT-PVDF electrode showed a better performance than that of Ag-CNT-PVDF, which seems to be related with lower contact resistance of Sulphur-CNT-PVDF electrode.

• 한국식품조리과학회지
• /
• 제15권4호
• /
• pp.410-417
• /
• 1999

우리나라 야산에서 쉽게 구할 수 있는 구황 식물인 질경이를 메탄올과 여러 용매로 추출하여 식품 부패 미생물에 대한 항균력을 실험하고 그 항균활성 물질을 분석하여 다음과 같은 결과를 얻었다. 질경이의 메탄올 추출물은 2000$\mu\textrm{g}$/ml 농도에서 B. subtilis 및 V. parahaemolyticus의 증식을 100% 억제하였다. 그리고 질경이의 ethylacetate 분획물은 1000$\mu\textrm{g}$/disc 농도에서 5종의 모든 실험 균주에 대하여 8.5~11mm 크기의 clear zone을 형성하여 가장 높은 항균력을 보였다. 질경이의 ethylacetate 분획물을 silica gel column chromatography와 TLC로 분리하여 얻은 fraction을 5가지 실험 균주에 대하여 항균 실험을 한 결과 3rd 분획물 중 4번째 분획물이 250$\mu\textrm{g}$/disc 농도에서 모든 균주에 대하여 10 mm 이상의 clear zone을 나타내었다. 항균력을 보인 질경이의 ethylacetate 3rd fraction No. 4를 HPLC로 단일 분리하여 얻은 peak IV로 부터 $^1$H-NMR 및 GC-MSD로 동정한 결과 hexadecanoic acid로 동정되었다.

• Journal of Ecology and Environment
• /
• 제42권4호
• /
• pp.240-258
• /
• 2018

Background: Several investigations carried out from large brackish lagoons in South Korea. However, no studies have yet examined phytoplankton in lagoons that changed to freshwater, such as Cheonjin Lake. The present study examined the algae from Cheonjin Lake. Methods: Samples were collected at monthly inetrvals from May 2017 to April 2018, from the surface layer using a plankton net (mesh size $20{\mu}m$), and sequeezing submerged macrophytes. Microscopic examinations were conducted at a magnification of 200 to 1000x using a Zeiss microscope (Axio Imager. A2), and photographs were taken with an AxioCam HRC camera. Silica-scaled samples of Chrysophyta for SEM were placed on coverglass, air dried, coated with gold, and then examined with a Hitachi SV8220 SEM. Results: A total of 376 taxa from six major algal groups (Chlorophyta, Chrysophyta, Euglenophyta, Cyanophyta, Dinophyta, and Cryptophyta) were identified. Among these algae, 28 taxa of desmids, 9 taxa of Euglenophyceae, 4 taxa of Chlorophyceae, 2 taxa of Chrysophyceae, and 1 taxon of Xanthophyceae are reported for the first time in Korea. A new species, Cosmarium hexagonum sp. nov was described. The phytoplankton communities were characterized by an abundance of Desmids (within Charophyceae) accounted for 148 taxa from 22 genera. Species richness were particularly high in the Autumn. Conclusion: In this study, a total 376 taxa of 148 desmids (Charophyceae), Chlorophyceae (103 taxa), Chrysophyceae (53 taxa), Euglenophyta (49 taxa), Dinophyta (8 taxa), and Cryptophyta (2 taxa) were identified from Cheonjin Lake. Twenty-eight taxa of desmids including a new species (Cosmarium hexagonum sp. nov.), 9 taxa of Euglenophyceae, 4 taxa of Chlorophyceae, 2 taxa of Chrysophyceae, and 1 taxon of Xanthophyceae were newly recorded in Korea.

• 대한본초학회지
• /
• 제32권2호
• /
• pp.97-105
• /
• 2017

Objectives : Gardeniae Fructus is a ripe fruit of Gardenia jasminoides Ellis, which has been used as traditional medicines for anti-inflammatory, diuretic, antipyretic, and antibacterial activity. The aim of this study was to compare of Gardeniae Fructus in South Korea collected during three years according to the standards in monographs of the Korean Pharmacopoeia Eleventh edition (KP11). Methods : 30 items of Gardeniae Fructus from two cultivation regions were classified into dried(n=15) & steamed (n=15) and tested according to the standards in monographs of the KP11. Gardeniae Fructus was carried out identification(comparison of colors, thin layer chromatography), heavy metals, residual pesticides, total ash, and assay registered at KP11. Add to we tested loss on dry, contents of ethanol-soluble extracts, and HPLC profiling. Results : In TLC chromatogram of identification test, the spot of gardenoside and geniposide were observed at $R_f$ value of about 0.3 and 0.5. Heavy metals and residual pesticides met the requirements of the standards for all samples. The results of total ash of each samples are measured maximum 4.87 %. According to HPLC for assay, the samples contain 4.80~6.10 % of geniposide and 0.45~1.83 % of gardenoside. Conclusion : We have verified the current specification standard of Gardeniae Fructus and standard that is not set. By the results, it is proposed a new draft of loss on drying and confirmed the content of gardenoside revised. HPLC standard chromatogram of Gardeniae Fructus is proposed. We hope that it will help the standardization of Gardeniae Fructus.

• 한국동물위생학회지
• /
• 제46권1호
• /
• pp.1-13
• /
• 2023

Fatty liver hemorrhagic syndrome (FLHS) is a metabolic disorder found in caged layer hens and causes reduced egg production and sudden death. Dandelion (Taraxacum coreanum, TC) and milk thistle (Cirsium japonicum var. ussuriense, CJ) are well known wild herbs inhabiting Korean peninsula and presenting antioxidative effects. This study investigated alleviate effects of these herbal mixture (6:4, w/w) composed of dried powder of TC and CJ against fatty liver in laying hens. The herbs mixture 5.0, 10.0, 20.0 or 40.0 g/kg feed was provided via feed admixture for 3 weeks to laying hens having FLHS. FLHS was induced by intramuscular injection of β-estradiol (2 mg/kg bw) 2 times per week for 3 weeks and supply with high caloric feed. Egg production rate was reduced from 76.2% at pre-treatment to 49.4% at 1 week and further decreased according to β-estradiol treatment. Increment of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (T-Chol) and total bilirubin (T-Bil) and decrement of serum superoxide dismutase (SOD) and glutathione peroxidase (GPX) with fatty liver were found by the treatment of β-estradiol. Supplementation of TC and CJ mixture via feed admixture recovered the reduction of egg production and attenuated serological changes and gross and pathological lesions of fatty liver with the best amelioration effects at 5 and 10 g TC and CJ mixture per kg feed. In conclusion, TC and CJ mixture attenuates FLHS by means of antioxidative effects. Further mechanistic study is required to explain TC and CJ's amelioration effects against FLHS in laying hens.

• 한국식품영양과학회지
• /
• 제22권3호
• /
• pp.307-312
• /
• 1993

감잎의 메탄올 추출물이 Salmonella typhimurium TA100에서 aflatoxin B$_1$(AFB$_1$), DMAB, MNNG, 그리고 4-NQO의 돌연변이 유발성을 억제시키는 효과가 있었다. 메탄올 추출물을 다시 hexane, chloroform, ethyl acetate, butanol, 그리고 수용성층으로 분획하여 각 획분의 수득율과 항돌연변이 효과를 조사하였다. Hexane, butanol, 그리고 수용성 획분의 수득율이 높았으며, 이중 hexane 획분이 AFB$_1$, DMAB, MNNG, 그리고 4-NQO에 대한 Salmonella typhimurium TA100에서 항돌연변이효과가 가장 크게 나타났다. Hexane 획분을 silica gel column과 thin layer chromatography (TLC)법으로 연속분리하여 TLC상에서 8개의 bands로 분리하였다. 그중 항돌연변이 효과가 가장 컸던 band를 hexane/ethylacetate (1 : 1, v/v)로 추출한 다음 그중에 존재하는 화합물을 GC-MS를 이용하여 분리동정하였다. 활성획분에서는 1'-oxocannabinol, 3$\beta$-acetoxy-17-methyl-5$\alpha$-18 (13-17) abeoard-rost-13-ene, 4-methoxy-2'6'-dinitro-3,5-di-t-butylbiphenyl, 8, 9-dihydro-5,6-dimethoxy-dibenz［c,h］isoquino ［2, 1, 8-1ma］carbazole-11, 16-dione 등이 분리동정되었다.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 2003년도 하계 학술대회 논문집
• /
• pp.309-316
• /
• 2003

참깨탈곡의 생력기계화를 위해 일관작업이 가능한 참깨탈곡기를 개발하여 시험한 결과를 요약하면 다음과 같다. 가. 타격식 탈곡요인시험 결과 타격수 14, 17cpm에서 탈곡률은 98.5, 98.7%, 미탈곡률은 1.1, 1.0%, 배출구 손실률은 0.4. 0.3%로 가장 양호하게 나타났다. 나. 타격식 탈곡물의 정선요인시험결과 경사 12$^{\circ}$, 요동수 220cpm일 때 탈곡률과 미정선 손실률이 각각 97.2%와 0.6%로 가장 양호하게 나타났다. 다. 타격식 탈곡부와 정선부를 조합한 시작기의 성능시험결과 공급량 15단/min, 타격수 14cpm, 정선체 요동수 220cpm에서 탈곡률은 98.7%, 탈곡부 손실률은 1.3%, 정선율은 97.0%, 미정선 손실률 0.7%로 나타났다. 라. 시작기는 10a당 작업성능이 0.5시간으로 인력 4.8시간에 비해 9.6배 능률적이고 소요경비가 17,471원으로 인력 32,290원에 비해 45.9% 절감되는 것으로 나타났다

• 대한치과보철학회지
• /
• 제45권5호
• /
• pp.601-610
• /
• 2007

Statement of problem: The adhesion between titanium and ceramic is less optimal than conventional metal-ceramic bonding, due to reaction layer form on cast titanium surface during porcelain firing. Purpose: This study characterized the effect of titanium-ceramic adhesion after gold and TiN coating on cast and wrought titanium substrates. Material and method: Six groups of ASTM grade II commercially pure titanium and cast titanium specimens$(13mm{\times}13mm{\times}1mm)$ were prepared(n=8). The conventional Au-Pd-In alloy served as the control. All specimens were sandblasted with $110{\mu}m\;Al_2O_3$ particles and ultrasonically cleaned for 5min in deionized water and dried in air before porcelain firing. An ultra-low-fusing dental porcelain (Vita Titankeramik) was fused on titanium surfaces. Porcelain was debonded by a biaxial flexure test at a cross head speed of 0.25mm/min. The excellent titanium-ceramic adherence was exhibited by the presence of a dentin porcelain layer on the specimen surface after the biaxial flexure test. Area fraction of adherent porcelain (AFAP) was determined by SEM/EDS. Numerical results were statistically analyzed by one-way ANOVA and Student-Newman-Keuls test at ${\alpha}=0.05$. Results: The AFAP value of cast titanium was greatest in the group 2 with TiN coating, followed by group 1 with Au coating and the group 3 with $Al_2O_3$ sandblasting. Significant statistical difference was found between the group 1, 2 and the group 3 (p<.05). The AFAP value of wrought titanium was greatest in the group 5 with TiN coating, followed by the group 4 with Au coating and the group 6 with $Al_2O_3$ sandblasting. Conclusion: No significant difference was observed among the three groups (p>.05). The AFAP values of the cast titanium and the wrought titanium were similar. However the group treated with $Al_2O_3$ sandblasting showed significantly lower value (p<.05).

• 한국식품조리과학회지
• /
• 제16권5호
• /
• pp.445-452
• /
• 2000

우리나라 야산에서 손쉽게 구할 수 있는 구황식물인 백작약을 건조시켜 분쇄한 후 methanol과 여러용매로 추출하여 식품 부패 미생물의 증식 억제 효과를 검색하고 그 향균물질을 분석하여 다음과 같은 결과를 얻었다. 백작약의 methanol 추출물은 1500$\mu\textrm{g}$/ml 농도에서 B. subtilis, S. aureus, V parahaemolyticus의 증식을 100% 억제하였으며 L. monocytogenes와 E. coli도 같은 농도에서 각각 65.93%와 83.27%의 억제 효과를 보였다. 백작약의 ethylacetate 분획 추출물은 낮은 농도인 1000$\mu\textrm{g}$/disc의 농도에서 식품 부패 미생물 5종 모두에 대하여 clear zone을 형성하여 항균력을 나타내었다. 특히 S. aureus, B. subtilis, V. parahaemolyticus, E. coli균에 대해서는 낮은 농도인 500$\mu\textrm{g}$/disc에서 clear zone을 나타내었으며 또한 2,000$\mu\textrm{g}$/disc 농도에서 L. monocytogenes, E. coli 및 V. parahaemolyticus는 각각 13, 15, 13m의 clear zone을 형성하였다. 백작약의 Ethylacetate 추출물을 silica gel colum chromatograhpy (7cm$\times$1.2cm한 후 thin layer chromatography(TLC)를 실시하여 항균성 실험을 한 결과 B. subtilis의 경우 1000$\mu\textrm{g}$/disc 농도에서 2nd fra. 3이 17mm, L. monocytogenes는 250$\mu\textrm{g}$/disc 농도에서 21mm를, S. aureus는 13mm의 clear zone을 형성하여 백작약의 methanol 추출물로부터 간 용매별로 계통 분획하여 분리한 ethylacetate 분획으로부터silica gel column chromatograpy와 TLC를 하여 항균성을 보인 2rd fra. 3의 성분을 알아보기 위히여 HPLC로 단일분리하여 얻은 peak III에 대한 compound를 GC-MS로 분석한 결과 peak III에서는 Cetyl alcohol이 있는 것으로 추정되었다.

• Restorative Dentistry and Endodontics
• /
• 제25권2호
• /
• pp.243-253
• /
• 2000

The purpose of this in vitro study was to evaluate dentin bonding by two different dentin bonding systems(DBS) using acetone based primer or adhesive [All Bond 2(AB2), One Step(OS)] when they were applied by wet or dry bonding technique. Morphology of resin-dentin interface and hybrid layer thickness(HLT) were investigated using Confocal Laser Scanning Microscope(CLSM) and compared to shear bond strength(SBS). 72 extracted sound human molars were randomly divided into 4 groups of 18 teeth each - Group 1.(AW); AB2 by wet bonding. Group 2(AD); AB2 by dry bonding. Group 3.(OW); OS by wet bonding, Group 4.(OD); OS by dry bonding. In 6 teeth of each group, notch-shaped class V cavities(depth 2mm) were prepared on buccal and lingual surface at the cementoenamel juction(12 cavities per group). To obtain color contrast in CLSM observation, bonding resins of each DBS were mixed with rhodamine B and primer of AB2 was mixed with sodium fluorescein. Prepared teeth of each group were treated with AB2, OS, respectively according to the manufacturer's instructions except for dentin surface moisture treatment after acid etching. In group 1 and 3, after acid etching, excess water was removed with wet tissue(Kimwipes), leaving consistently shiny, visibly hydrated dentin surface. In group 2 and 4, dentin surface was dried for 10 seconds at 1 inch distance. The treated teeth were then packed with composite resin(${\AE}$litefil) and light-cured. 12 microscopic samples($60{\sim}80{\mu}m$ thickness) of each group were obtained after longitudinal section and grinding(Exakt cutting and grinding system). Morphological investigation of resin-dentin interface and HLT measurement using CLSM were done. For measurement of SBS, remaining 12 teeth of each group were flattened occlusally to remove all enamel and grinded to 500 grit SiC(Pedemet Specimen Preparation Equipment). After applying DBS on the exposed dentin surface, composite resin was applied in the shape of cylinder, which has 5mm diameter, 1.5mm thickness, and light cured. SBS was measured using Instron with a crosshead speed of 0.5mm/min. It was concluded as follows, 1. HLT of AW(mean: $2.59{\mu}m$) was thicker than any other group, and followed by AD, OW, OD in descending order(mean; 2.37, 2.28, $1.92{\mu}m$). Only OD had statistically significant differences(p<0.05) to AW and AD. 2. There were intimate contact of resin and dentin at the interface in wet bonding groups, but gaps or irregular interfaces were observed in dry bonding groups. 3. The length, diameter, density of resin tags were various even in the same group without significant differences between groups and lots of adhesive lateral branches were observed. 4. There were no statistically significant difference of SBS between AB2 and OS, but SBS of wet bonding groups were significantly higher(p<0.05) than dry bonding groups. 5. There were no consistent relationships between HLT and SBS.