• Title/Summary/Keyword: purity analysis

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Manufacturing Technology and Provenance of the Lead Beads (납환의 제작방법 및 납동위원소비 특성 연구)

  • Kim, So-jin;Hwang, Jin-ju;Han, Woo-rim;Lee, Eun- woo;Rim, Seok-gyu;Jeong, Youn-joong
    • Korean Journal of Heritage: History & Science
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    • v.47 no.4
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    • pp.48-57
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    • 2014
  • More than 30 lead beads have been excavated from buddhist temples and sites but the production times are unknown the origin. The aim of this study is to estimate manufacturing technique and provenance of 11 beads through the chemical composition and isotope analysis. Results shows that the lead beads are composed of high-purity lead and cast using for 2 semicircle moulds. Furthermore, 11 lead beads are similar in size, chemical composition and casting methods. Lead isotope analysis data suggest that the provenance of lead beads are not Korea peninsula. Also it is estimated that 11 lead beads were divided in 2 groups considering the time and places of production. The future works will be executed additional scientific analysis and historical background due to confirm the manufacturing system and provenance.

Study on the Production Methods and Conservation Treatment of the Gold Earrings Excavated from the Ancient Tombs in Seokchon-dong in Seoul (석촌동 고분군 출토 금제이식의 제작기법 연구 및 보존처리)

  • Kim, Yeseung;Jeong, Seri;Lee, Dahye;Jang, Minkyeong;Kim, Naeun;Yang, Seokjin
    • Conservation Science in Museum
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    • v.26
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    • pp.143-160
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    • 2021
  • The Seoul Baekje Museum has been conducting excavations at the Ancient Tomb Complex in Seokchon-dong, Seoul (Historic Site No. 243), known to be tombs of the royal family and the ruling class during the Hanseong period of the Baekje Kingdom. In this study, gold earrings that were revealed during the excavation underwent scientific analysis and conservation treatment. Stereo microscopy, SEM, X-ray imaging, CT, and XRF were applied in the analysis, and the characteristics, internal structure, and composition of the earrings as well as their production method were investigated. The results confirmed that the main hoops of the gilt-bronze earrings were made of copper cores gilt using mercury amalgamation. The findings also revealed that the hexahedron in the middle pendant was made by connecting small rings using molten gold powder, and the pendant sphere at the end was formed by soldering two hemispheres. As for the two thin-hoop earrings, they showed similar surface compositions but were made using different methods, with one made from a copper core wrapped with a gold plate and the other made by bending a gold rod. The gold content varied depending on the item and the place of measurement, but overall the earrings showed a relatively high gold content of approximately 19 to 21K. The purity of the golden earrings and the sophisticated manufacturing techniques applied indicate the high status of the buried person and of the tomb complex in Seokchong-dong.

Identification of Maysin and Related Flavonid Analogues in Corn Silks (옥수수 수염에서 Maysin 및 유사물질의 동정)

  • Kim, Sun-Lim;Snook, Maurice E.;Kim, E-Hun;Park, Cheol-Ho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.3
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    • pp.151-157
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    • 2000
  • This study was carried out to isolate and identify the maysin and related flavonoid analogues in corn silks. Silks were covered with silk bag to prevent pollination and were sampled at 3-5 days after silking. The silks were filled with 100% MeOH and stored at $0^{\circ}C$ until analysis. The MeOH extracts of corn silks were filtered and concentrated at 35-4$0^{\circ}C$. The ${CH}_2$${Cl}_2$ was added on the concentrated aqueous solution to remove the chlorophyll and lipids. The Cis open column (25mm$\times$54 cm) was washed and activated with serial treatment of 500$m\ell$ of 100% MeOH(twice)longrightarrow75% MeOH longrightarrow50% MeOHlongrightarrow30% MeOHlongrightarrow100% $H_2$O(2 times). The concentrated aqueous solution was applied to the $C_{18}$ column and washed with $H_2O$ several times to remove the sugars and water soluble pigments. Neochlorogenic acid, chlorogenic acid and 4-caffeoylquinic acid were eluted with 10% MeOH, and rhamosyl isoorientin was eluted with 30% MeOH, but maysin was eluted with 50% MeOH from the $C_18$ open column. Collected fractions were analyzed with HPLC by using revers-phase Ultras-phere $C_{18}$ column (4.6$\times$250mm, 5$\mu\textrm{m}$) and $H_2$O (10% MeOH containing 0.1% $H_3$${PO}_4$)/MeOH (100% MeOH containing 0.1% H$_3$PO$_4$) linear gradient from 20% to 90% MeOH for 35 minutes, a flow rate of 1 $m\ell$/min and detection at 340nm. The selected fractions were concentrated and applied to the silicic acid column. Maysin was eluted with 500$m\ell$ of 100% ethyl acetate from the silicic acid column for the first purification, and the purity of collected fractions was about 75%, but the purity from the second purification with the Cis column (1/2 $\times$ 43") was greater than 95%. FAB-MS spectral data was obtained with VG7O-VSEQ VG analytical fast atom bombardment mass (UK). $^1$H-NMR and $^{13}$ C-NMR data were obtained with Bruker DPX 400 MHz NMR spectrometers (German) in DMSO-d$_{6}$ at 400 and 100 MHz, respectively.vely.

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Detection and Measurement of Nuclear Medicine Workers' Internal Radioactive Contamination (핵의학과 종사자의 방사성동위원소 체내오염 측정)

  • Jeong, Gyu-Hwan;Kim, Yong-Jae;Jang, Jeong-Chan;Lee, Jai-Ki
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.123-131
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    • 2009
  • Purpose: We tested a sample of nuclear medicine workers at Korean healthcare institutions for internal contamination with radioactive isotopes, measuring concentrations and evaluating doses of individual exposure. Materials and Methods: The detection and measurement was performed on urine samples collected from 25 nuclear medicine workers at three large hospitals located in Seoul. Urine samples were collected once a week, 100~200 mL samples were gathered up to 6~10 times weekly. A high-purity germanium detector was used to measure gamma radiations in urine samples for the presence of radioactive isotopes. Based on the detection results, we estimated the amounts of intake and committed effective doses using IMBA software. In cases where committed effective doses could not be adequately evaluated with IMBA software, we estimated individual committed effective doses for radionuclides with a very short half life such as $^{99m}Tc$ and $^{123}I$, using the methods recommended by International Atomic Energy Agency. Results: Radionuclides detected through the analysis of urine samples included $^{99m}Tc$, $^{123}I$, $^{131}I$ and $^{201}Tl$, as well as $^{18}F$, a nuclide used in Positron Emission Tomography examinations. The committed effective doses, calculated based on the radionuclide concentrations in urine samples, ranged from 0 to 5 mSv, but were, in the majority of cases, less than 1 mSv. The committed effective dose exceeded 1 mSv in three of the samples, and all three were workers directly handling radioactive sources. No nurses were found to have a committed effective dose in excess of 1 mSv. Conclusions: To improve the accuracy of results, it may be necessary to conduct a long-term study, performed over a time span wide enough to allow the clear determination of the influence of seasonal factors. A larger sample should also help increase the reliability of results. However, as most Korean nuclear medicine workers are currently not necessary to monitored routinely for internal contamination with radionuclides. Notwithstanding, a continuous effort is recommended to reduce any unnecessary exposure to radioactive substances, even if in inconsequential amounts, by regularly surveying workplace environments and frequently monitoring atmospheric concentrations of radionuclides.

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Production of Alternative Coagulant Using Waste Activated Alumina and Evaluation of Coagulation Activity (폐촉매 부산물로부터 대체 응집제 제조 및 응집성능 평가)

  • Lee, Sangwon;Moon, Taesup;Kim, Hyosoo;Choi, Myungwon;Lee, Deasun;Park, Sangtae;Kim, Changwon
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.7
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    • pp.514-520
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    • 2014
  • In this study, the production potential of alternative coagulant ($Al_2(SO_4)_3$ solution) having the identical coagulation activity with respect to the commercial coagulant was investigated. The raw material of alternative coagulant was a spent catalyst including aluminium (waste activated alumina) generated in the manufacturing process of the polymer. The alternative coagulant was produced through a series of processes: 1) intense heat and grinding, 2) chemical polymerization and substitution with $H_2SO_4$ solution, 3) dissolution and dilution and 4) settling and separation. To determine the optimal operating conditions in the lab-scale autoclave and dissolver, the content of $Al_2O_3$ in alternative coagulant was analyzed according to changes of the purity of sulfuric acid, reaction temperature, injection ratio of sulfuric acid and water in the dissolver. The results showed that the alternative coagulant having the $Al_2O_3$ content of 7~8% was produced under the optimal conditions such as $H_2SO_4$ purity of 50%, reaction temperature of $120^{\circ}C$, injection ratio of $H_2SO_4$ of 5 times and injection ratio of water of 2.3 times in dissolver. In order to evaluate the coagulation activity of the alternative coagulant, the Jar-test was conducted to the effluent in aerobic reactor. As a result, in both cases of Al/P mole of 1.5 and 2.0, the coagulation activity of the alternative coagulant was higher than that of the existing commercial coagulant. When the production costs were compared between the alternative and commercial coagulant through economic analysis, the production cost reduction of about 50% was available in the case of the alternative coagulant. In addition, it was identified that the alternative coagulant could be applied at field wastewater treatment plant without environmental problem through ecological toxicity testing.

A Study on the Knowledge. Attitude and Behavior of Commercial Girl's High School Students Toward Sex (서울시내 실업계 여고생들의 성지식 태도 및 행위에 관한 조사연구)

  • Bae, Nam-Sook
    • Korean Journal of Health Education and Promotion
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    • v.1 no.1
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    • pp.57-71
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    • 1983
  • Sex education is necessary for the youth that they should have an adequate sexual knowledge, attitudes and behaviors in their adolescent period. Four major objectives of this study are as follows; 1. To know the level of sexual knowledge of commercial girl's high school students in Seoul. 2. To know their actual state for the attitudes and behaviors toward sex. 3. To compare the sexual knowledge, attitudes and behaviors of day time school students with those of night time school students. 4. To compare the factors associated with their sexual knowledge, attitudes and behaviors with the individual level. Data were collected on 986 students in Seoul from April 1 to April 10, 1983. As the result of this survey, the following conclusions were obtained. 1. The level of sexual knowledge. (1) The level of knowledge of day time high school students about the physiology of female and pregnancy is shown higher than those of night time students. 64.2% of the respondents are aware of the organ producing ovum. 56.4% the ovulation period. 95.6% the cause of pregnancy. 74.5% the pregnantable period and 12.7% the place of fetilization. (2) Out of 986 respondents. 71.8% knew about contraceptive method correctly, and day time school students knew litter better than night time school students, by showing 73.9% and 69.7% respectively. They knew about contraceptive method with 'oral pills'. 'menstrual cycles', 'condoms'. and 'loops' in the same order. 3) Kinds of veneral disease was correctly known by 37.9%. Day time students knew much better than night time school students. by showing 67.8% and 7.9%. respectively. Transmission method of veneral disease was correctly known by 28.3%. Day time students knew much better than night time students, by showing 51.2% and 5.3%, respectively. (4) The major information source of sexual knowledge was 'book and magazine' (39.9%) and 'friends' (27.4%). 2. Actual state of attitudes and behaviors toward sex. (1) Out of 986 respondents, 84.0% answered that premarital purity should be kept. (2) Out of 986 respondents, 60.8% had an acquaintance of the opposite sex. 45.2% of students with opposite sex reported introduction of their friends as the main channel of making an acquaintance of the opposite sex. (3) Of those who responded to this study 13.8% reported having masturbation, 21.5% kissing, 6.2% petting and 3.7% sex intercourse. (4) 64.8% had sexual problems, which was mensturance (27.2%), aquaintance of the opposite sex (25.4%). The main method to solve the problems were consultation with 'friends' and 'books and magazine' percentage being 39.1% and 30.8%, respectively, whereas very small students discussed with 'teachers' and 'parents' percentages being 0.3% and 5.9%, respectively. (5) Out of 986 respondents, 62.2% had experience in educating about sex, the percentage of day time school was higher than that of night time school. (6) 88.2% of students wanted sex education in school, which were 'general information about sex' (35.4%), 'sexual morality and solution of sexual desire' (18.5%), 'aquaintance of the opposite sex' (13.3%) and 'marriage and role of man and woman' (12.4%) in the same order. They wanted to be instructed about sexes in the lecture of physical education, home economics, biology, military training (59.9%), regular curriculum (17.5%), special lecture (16.9%) and by the counselor or school nurse (5.7%). 3. Analyse concerning the factors about the knowledge, attitudes and behaviors. (1) The better school record was, the higher the level of sexual knowledge. (2) Those who have the religion considered the permarital purity more important than those who have not, the percentage showing 86.7% and 80.7%, respectively. (3) The result of dyad analysis of making acquaintance of the opposite sex in the friendship network showed that a high index of the acquaintance of the opposite sex tends to be a high adoption of making one at the individual level in the group, while the low index tends to be a low adoption of making one in the group.

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Liposome Formation and Active Ingredient Capsulation on the Supercritical Condition (초임계 상태에서 리포좀의 생성 및 약물봉입)

  • Mun, Yong-Jun;Cha, Joo-Hwan;Kim, In-Young
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.6
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    • pp.1687-1698
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    • 2021
  • This study is to produce multiple layers of liposomes in a supercritical state and encapsulates active ingredients in order to stably encapsulate thermodynamically unstable active ingredients. In order to form a liposome in a supercritical state, a mixed surfactant development including vegetable-derived hydrogenated phosphatidyl choline and their delivative, hydrogenated sucrose distearate was synthesized as high purity. It describes a manufacturing method of injecting liquid carbon dioxide into a reactor to create a supercritical state and stirring to produce a giant liposome, and adding and loading genistein and quercetin. The HLB of the mixed lipid complex (SC-Lipid Complex) was 12.50, and multiple layers of liposome vesicles were formed even at very low concentrations. This surfactant had a specific odor with a pale yellow flake, the specific gravity was 0.972, and the acid value was 0.12, indicating that it was synthesized with high purity. As a result of the emulsifying capacity experiment using 20 wt% capric/capric triglyceride and triethylhexanoin using SC-Lipid Complex, it was found to have 96.2% emulsifying power. SC LIPOSOME GENISTEIN was confirmed that a multi-layer liposome vesicle was formed through a transmission electron microscope (Cryo-TEM) for the supercritical liposome encapsulated with genistein. The primary liposome particle size in which genistein was encapsulated was 253.9 nm, and the secondary capsule size was 18.2 ㎛. Using genistein as the standard substance, the encapsulation efficiency of supercritical liposomes was 99.5%, and general liposomes were found to have an efficiency of 93.6%. In addition, the antioxidant activity experiment in which quercetin was sealed was confirmed by the DPPH method, and it was found that the supercritical liposome significantly maintained excellent antioxidant activity. In this study, thermodynamically unstable raw materials were sealed into liposomes without organic solvents in a supercritical state. Based on these results, it is expected that it can be applied to various forms such as highly functional skincare cosmetics, makeup cosmetics, and scalp protection cosmetics.

Molecular Characterization of Rathi and Tharparkar Indigenous Cattle (Bos indicus) Breeds by RAPD-PCR

  • Sharma, Amit Kumar;Bhushan, Bharat;Kumar, Sanjeev;Kumar, Pushpendra;Sharma, Arjava;Kumar, Satish
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.9
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    • pp.1204-1209
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    • 2004
  • Random amplification of polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) analysis was carried out using DNA samples of 30 animals of Rathi cattle and 42 animals of Tharparkar cattle. Genomic DNA was isolated as per standard protocol and evaluated for its quality, purity and concentration. Twenty three random primers were screened out of which 15 primers yielded satisfactory amplifications and were used for further analysis. Average numbers of polymorphic fragments per primer were 7.07${\pm}$0.86 in Rathi and 6.80${\pm}$0.61 in Tharparkar cattle. The percentage of polymorphic bands in these two cattle breeds were 86 and 87%, respectively. Within breed genetic similarities for pooled over primers in the animals of Rathi and Tharparkar breeds were .577${\pm}$0.30 and 0.531${\pm}$0.02, respectively on the basis of band frequency (BF) and 0.645${\pm}$0.04 and 0.534${\pm}$0.04, respectively on the basis of band sharing (BS). Averages of between breed genetic similarities for pooled over primers were 0.97 and 0.92 according to BF and BS, respectively, which reflect higher degree of genetic similarity between Rathi and Tharparkar cattle breeds. Index of genetic distance based on BF and BS for pooled over primers was 0.030${\pm}$0.011 and 0.088${\pm}$0.031, respectively. Percentage of polymorphic bands and within-breed genetic similarities on the basis of band frequency (BF) and band sharing (BS) for pooled over primers revealed higher genetic similarity in Rathi than Tharparkar cattle population. High estimates of between breed genetic similarities for pooled over primers indicated that either Rathi is having decent from Tharparkar or both the cattle breeds are having common descent. Low value of Index of genetic distances between these two cattle breeds may be due to the fact that Rathi and Tharparkar cattle breeds are the native of Thar Desert in Northwest India. The results of between breed genetic distances also confirm the existence of high degree of genetic similarity between these two breeds of cattle.

Authentication of Sesame Oil with Addition of Perilla Oil Using Electronic Nose Based on Mass Spectrometry (전자코-Mass spectrometry를 이용한 들기름이 혼합된 참기름의 판별 분석)

  • Son, Hee-Jin;Kang, Jin-Hee;Hong, Eun-Jeung;Lim, Chae-Lan;Choi, Jin-Young;Noh, Bong-Soo
    • Korean Journal of Food Science and Technology
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    • v.41 no.6
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    • pp.609-614
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    • 2009
  • Sesame oil was sometimes replaced by mixed oil due to high price in Korean market. To find out authentic sesame oil, electronic nose (E-nose) based on mass spectrometer system was used. Sesame oil was blended with perilla oil at the ratio of 97:3, 94:6, 91:9, 88:12 and 85:15, respectively. Intensities of each fragment from sesame oil by E-nose based on MS were completely different from those of perilla oil. The obtained data was used for discriminant function analysis. For quantitative analysis, the partial least square algorithm was used. The added concentration of perilla oil to sesame oil was correlated with discriminant function first score (DF1) and second score (DF2). From this relationship it could be found out how much perilla oil added. DFA plot indicated a significant separation of pure sesame oil and pure perilla oil. The different geographical origin of sesame oil was used for blending with perilla oil were closed to that of sesame oil. Korean sesame oil mixture and Indian sesame oil one were well separated. And the correlation between mixing ratios and DF1 values was found at the ratio of 97:3, 91:9, and 85:15 (SE vs PE oil), respectively. But the added concentration of perilla oil to sesame oil was correlated with discriminant function first score (DF1). E-nose based on MS system could be used as an efficient method for purity of oil quality.

A Study on Performance Characteristic and Safety of Alkaline Water Electrolysis System (알카라인 수전해 시스템 성능 특성 및 안전에 관한 연구)

  • PARK, SOON-AE;LEE, EUN-KYUNG;LEE, JUNG-WOON;LEE, SEUNG-KUK;MOON, JONG-SAM;KIM, TAE-WAN;CHEON, YOUNG-KI
    • Journal of Hydrogen and New Energy
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    • v.28 no.6
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    • pp.601-609
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    • 2017
  • Hydrogen is a clean, endlessly produced energy and it is easy to store and transfer. So, hydrogen is regarded as next generation energy. Among various ways for hydrogen production, the way to produce hydrogen by water electrolysis can effectively respond to fossil fuel's depletion or climate change. As interest in hydrogen has increased, related research has been actively conducted in many countries. In this study, we analyzed the performance characteristics and safety of water electrolysis system. In this study, we analyzed the performance characteristics and safety of water electrolysis system. The items for safety performance evaluation of the water electrolysis system were derived through analysis of international regulations, codes, and standards on hydrogen. Also, a prototype of the overall safety performance evaluation station was designed and developed. The demonstration test was performed with a prototype $10Nm^3/h$ class water electrolysis system that operated stably under various pressure conditions while measuring the stack and system efficiency. At 0.7MPa, the efficiency of the alkaline water electrolysis stack and the system that used in this study was 76.3% and 49.8% respectively. Through the GC analysis in produced $H_2$, the $N_2$ (5,157ppm) and $O_2$ (1,646 ppm) among Ar, $O_2$, $N_2$, CO and $CO_2$ confirmed as main impurities. It can be possible that the result of this study can apply to establish the safety standards for the hydrogen production system by water electrolysis.