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The Flow-rate Measurements in a Multi-phase Flow Pipeline by Using a Clamp-on Sealed Radioisotope Cross Correlation Flowmeter (투과 감마선 계측신호의 Cross correlation 기법 적용에 의한 다중상 유체의 유량측정)

  • Kim, Jin-Seop;Kim, Jong-Bum;Kim, Jae-Ho;Lee, Na-Young;Jung, Sung-Hee
    • Journal of Radiation Protection and Research
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    • v.33 no.1
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    • pp.13-20
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    • 2008
  • The flow rate measurements in a multi-phase flow pipeline were evaluated quantitatively by means of a clamp-on sealed radioisotope based on a cross correlation signal processing technique. The flow rates were calculated by a determination of the transit time between two sealed gamma sources by using a cross correlation function following FFT filtering, then corrected with vapor fraction in the pipeline which was measured by the ${\gamma}$-ray attenuation method. The pipeline model was manufactured by acrylic resin(ID. 8 cm, L=3.5 m, t=10 mm), and the multi-phase flow patterns were realized by an injection of compressed $N_2$ gas. Two sealed gamma sources of $^{137}Cs$ (E=0.662 MeV, ${\Gamma}$ $factor=0.326\;R{\cdot}h^{-1}{\cdot}m^2{\cdot}Ci^{-1}$) of 20 mCi and 17 mCi, and radiation detectors of $2"{\times}2"$ NaI(Tl) scintillation counter (Eberline, SP-3) were used for this study. Under the given conditions(the distance between two sources: 4D(D; inner diameter), N/S ratio: $0.12{\sim}0.15$, sampling time ${\Delta}t$: 4msec), the measured flow rates showed the maximum. relative error of 1.7 % when compared to the real ones through the vapor content corrections($6.1\;%{\sim}9.2\;%$). From a subsequent experiment, it was proven that the closer the distance between the two sealed sources is, the more precise the measured flow rates are. Provided additional studies related to the selection of radioisotopes their activity, and an optimization of the experimental geometry are carried out, it is anticipated that a radioisotope application for flow rate measurements can be used as an important tool for monitoring multi-phase facilities belonging to petrochemical and refinery industries and contributes economically in the light of maintenance and control of them.

A Development and Application of the Landscape Evaluation Model Based on the Biotope Classification (비오톱 유형분류를 기반으로 한 경관평가 모형개발 및 적용)

  • Park, Cheon-Jin;Ra, Jung-Hwa;Cho, Hyun-Ju;Kim, Jin-Hyo;Kwon, Oh-Sung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.4
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    • pp.114-126
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    • 2012
  • The purpose of this study is to find ways of the view evaluation of biotope classification before development by selecting an area, which is as large as about $10.0km^2$ around Non Gong Up, Auk Po Myun, Dalsung Gun, Daugu where the large project has been planned, as a subject of this study. The results of this study are as follows. Because of the classification of biotope, there are 23 kinds of types that are subdivided into 140 types. Three surveys for selecting the assessment indicators were performed. The first survey analyzed the importance of 22 selected assessment indicators based on the evaluation of an existing literature review and on the spot research. The second survey performed factor analysis and reclassified the value indicators. The third survey computed additive values of the selected assessment indicators. It used a method of standardizing the average importance of indicators by making their sum equal by 10. Theses additive values were then multiplied by each grade of indicators in order to make a final evaluation. The number of assessment indicators finally selected through the survey of asking specialist is vitality elements, visual obstructs elements etc 19. According to the result of evaluation of 1st, 1 grade spaces which especially valuable is analyzed that 7 spaces, 2 grade spaces for 4, 3 grade spaces for 5, 4 grade space for 2, 5 grade space for 5. Because of the evaluation of 2st, 1 grade spaces which especially valuable(1a, 1b) is analyzed that 15 spaces, 2 grade spaces which valuable is analyzed that 28 space. As the evaluation of site suitability model of this study couldn't have high applicability to other similar area because of having only one site as a subject, it is needed to do synthesize and standardization of various examples to have higher objectivity later.

Chemical Structures and Physiological Activities of Plant Growth Substance, Malformin B's (식물생장조절물질 말포민 B동족체의 화학구조 및 생리활성)

  • Kim, K.W.
    • Korean Journal of Weed Science
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    • v.15 no.1
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    • pp.85-98
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    • 1995
  • Six malformin B's produced by Aspergillus niger van Tiegh. were separated by HPLC. Their structures determined by the methods of amino acid analyses, mass spectrometry, and two-dimensional NMR were revealed as cyclic pentapeptides structurally related to malformin $A_1$. Both the NMR and MS/MS data suggest that the respective structures of separated malformin B's were as follows; cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-allo-Ile for $B_{1a}$, cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-Leu for $B_{1b}$, cyclo-D-Cys-D-Cys-L-Val-D-Val-L-Leu for $B_2$, cyclo-D-Cys-D-Cys-L-Val-D-Ile-L-Leu for $B_3$, cyclo-D-Cys-D-Cys-L-Val-D-Ile-L-Ile for $B_4$, and cyclo-D-Cys-D-Cys-L-Val-D-Val-L-Ile for $B_5$. Among the malformin B's, the structure of $B_{1b}$ was the same as that of malformin $A_3$ or C. All the malformin B's showed physiological activities in the two assay systems using corn(Zea mays L.) roots and mung bean(Phaseolus aureus Roxb.) hypercotyl segments. The malformin B's with molecular weight 529 were more effective for inducing corn root curvature than those with molecular weight 515. The difference in molecular weight of malformin B's, i.e., the retention time on HPLC, results in the polarity change of the whole malformin molecule which affects the revealation of the malformin activities. In addition, the disulfide form of the malformin B's gives the rigidity of the molecule, whereas the combination of the fourth and the fifth amino acid residues provides the optimal three-dimensional configuration to the malformin receptor of plants. Presumably, these two factors are appeared to be essential for the greatest physiological activity of malformin B's. malformin $B_{1a}$ caused the corn root curvature by 90% at a concentration of $0.25{\mu}M$. However, such differential activities with molecular weight of 529 or 515 of malformin B's were not found in the mung bean hypercotyl segment test. Maximum stimulation of mung bean hypercotyl growth was observed at $0.1{\mu}M$ concentration of malformin B's. The growth of the segments treated with $B_5$ was 154% greater than that of the control.

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Isolation and Characterization of Tartaric Acid-Degrading Bacteria from Korean Grape Wine Pomace (국산 포도주 주박으로부터 주석산 분해 세균의 분리 및 특성)

  • Kim, Jong-Hyun;Choi, Sang-Hoon;Hong, Young-A;Kim, Dong-Hwan;Lee, Won-Hee;Rhee, Chang-Ho;Park, Heui-Dong
    • Food Science and Preservation
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    • v.15 no.3
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    • pp.483-490
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    • 2008
  • Several tartaric acid-degrading bacteria were isolated from Korean grape wine pomace after enrichment culture at $30^{\circ}C$ for 10 days in liquid media containing tartaric acid Among them, strains KMBL 5777 and KMBL 5778 exhibited the highest level in the growth and tartaric acid degradability in a medium containing 0.2%(w/v) tartaric acid as a sole carbon source. They were identified as Acetobacter tropicalis based on their morphological and physiological characteristics as well as their 16S rDNA sequences. Blast search of the 16S rDNA sequences revealed that the isolated strains are closest to Acetobacter tropicalis. Homologies of the sequences of KMBL 5777 and KMBL 5778 were 96.0 and 98.9%, respectively with those of A. tropicalis LMG 1663. Both the two bacteria showed higher tartaric acid degradation at $25^{\circ}C$ that those at 20 and $30^{\circ}C$. They could degrade tartaric acid at a wide range of pH between 4.0 and 7.0 with the most rapid degradability at pH 7.0. However, when the bacteria were grown for 8 days, the same level of tartaric acid degradation was observed at pH 4.0, 5.0, 6.0 and 7.0, which was 90.0% of degradation of the acid.

A Study on Labor Saving in Paddy Rice Cultivation (논벼재배에 있어서의 노동력 절감에 관한 연구)

  • Young-Chul Chang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.11
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    • pp.81-97
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    • 1972
  • Experiments and investigations were done basically and practically for the purpose of labor saving in paddy rice cultivation especially on Homizil i.e. hoeing and herbicide, 1969. 8 concrete tanks were established on the open base of Keon Kuk University for comparison of percolation, dissolved oxygen and yield test of rice in the paddy plot of tank. The dimension of the bottom of each tank is square meter. Each of the 4 of the 8 tanks is 21cm in height and each of the remaining 4 tanks is 36cm. Each tank has a system that comprises 2 sets of tubes, each of which has 20 holes of 5mm in diameter scattered every side and is covered with nylon cloth taking water in the tank. One set consists of 4 P.V.C tubes. The first set is situated 8cm below the top of the tank and the second set is located at bottom layer inside the tank. The 4 tubes of each set are combined together and led to the glass tube which protects from inside to outside. And this inside-outside glass tube is connected to the small rubber tube. Also a glass tube is set 4cm below the top of the tank. Paddy loam was filled on sand in each of the tanks in the soil depth of either 15cm or 30cm. The depth of sand was 5cm in the soil depth of 15cm and 10cm in the soil depth of 30cm. (Fig. 1, 2 and 3). The paddy rice was grown in the tank. The percolation of water, the dissolved oxygen and the yield of rice were observed in the tank. And the dissolved oxygen was detected by Winkler method. A sandy paddy field of heavy percolation was selected at the field of the National Agricultural Material Inspection Center in Seoul. It was divided into 9 plots. These plots were given 3 treatments: (A) not hoeing, (B) hoeing one time and (C) hoeing two times. These treatments were replicated 3 times along the latin square design. The paddy rice was grown and sprayed with Stam F-34 in the all plots for the purpose of killing weeds before hoeing. The two types of paddy of field i.e. one for normal percolation and the other for ill drainage were selected at Iri Crop Experiment Station, Jeonla-Bukdo. Each field was divided into 24 plots for 8 treatments. They are: (A) not hoeing; (B) hoeing one time; (C) hoeing two times; (D) not hoeing but treating with herbicide, Pamcon; (E) hoeing one time and weeding two times also treating with herbicide, Pamcon; (F) hoeing two times and weeding one time a], o treating with herbicide, Pamcon; (G) hoeing two times and weeding two times also treating with herbicide, Pamcon, ; (H) usual manner. The labor hours and expenses needed for weeding in the paddy by hoeing were investigated in a farmer at Suwon and the price of herbicide and the yield of rice were taken out at Iri, Jeonla-Bukdo. The results obtained from the above experiments and investigations are as follows: 1. The relationship between percolation and dissolved oxygen shows that a very small amount of oxygen is detected in the soil water under 2cm below surface of earth in the paddy even when percolation is over 4.0cm per 24 hours (Tab. 1). 2. The relationship between percolation and yield of rice shows that the yield of rice increases in the percolation of 0cm and 1.5cm per 24 hours and decreases in the percolation of 2.5cm and 3.4cm in the plot of the 15cm ploughing depth and increases in the percolation of 1.4cm and 3.0cm and decreases in the percolation of 0cm and 4.0cm in the plot of 30cm ploughing depth (Tab. 1 and Fig. 5). 3. The yield of paddy weeded with Stam F-34 in the sandy field of heavy percolation in Seoul was 3.02 tons in the plot of not hoeing, 2.99 tons in hoeing one time and 3.05 tons in hoeing two times per hectare (Tab. 5). 4.1). 4. 1) The yield of rice per 10 ares in the field of normal percolation at Iri was 338kg in not hoeing, 379kg in hoeing one time, 383kg in hoeing two times, 413kg in spraying herbicide, Pamcon, and not hoeing, 433kg in spraying herbicide, Pamcon, and hoeing one time and weeding two times, 399kg in spraying herbicide, Pamcon, and hoeing two times and weeding one time, 420kg in spraying herbicide, Pamcon, and hoeing two times and weeding two times and 418kg in usual manner (Tab. 6-1). 2) The yield of rice per 10 ares in the field of ill drainage at Iri was 323kg in not hoeing, 363kg in hoeing one time, 342kg in hoeing two times, 388kg in spraying herbicide, Pamcon, and not hoeing, 425kg in spraying herbicide, Pamcon, and hoeing one time and weeding two times, 427kg in spraying herbicide, Pamcon, and hoeing two times and weeding one time, 449kg in spraying herbicide, Pamcon, and hoeing two times and weeding two times and 412kg in usual manner (Tab. 6-2). 5. 1) The labor hours for weeding by hoeing was 37.1 hours but 53.5 hours if hours for meal, smoking and so on are included, and the expenses including labor cost needed for weeding by hoeing in the paddy rice was 2, 346 Won per 10 ares at Suwon (Tab. 7). 2) The labor hours for weeding by spraying herbicide with hand sprayer in the paddy rice was about 5 hours per 10 ares at Suwon and the expenses for weeding by spraying herbicide in the paddy rice was 750 Won but 1130 Won if the loss by decrement of rice in the paddy field of ill drainage per 10 ares is calculated in estimation at Iri (Tab. 8). From these observations and investigations it is known that using of some kinds of herbicides Saves labor and expenses of weeding, almost without giving damages to the rice itself, in the field of normal or heavy percolation comparing usual manner of hoeing.

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Study of Oil Palm Biomass Resources (Part 5) - Torrefaction of Pellets Made from Oil Palm Biomass - (오일팜 바이오매스의 자원화 연구 V - 오일팜 바이오매스 펠릿의 반탄화 연구 -)

  • Lee, Ji-Young;Kim, Chul-Hwan;Sung, Yong Joo;Nam, Hye-Gyeong;Park, Hyeong-Hun;Kwon, Sol;Park, Dong-Hun;Joo, Su-Yeon;Yim, Hyun-Tek;Lee, Min-Seok;Kim, Se-Bin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.2
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    • pp.34-45
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    • 2016
  • Global warming and climate change have been caused by combustion of fossil fuels. The greenhouse gases contributed to the rise of temperature between $0.6^{\circ}C$ and $0.9^{\circ}C$ over the past century. Presently, fossil fuels account for about 88% of the commercial energy sources used. In developing countries, fossil fuels are a very attractive energy source because they are available and relatively inexpensive. The environmental problems with fossil fuels have been aggravating stress from already existing factors including acid deposition, urban air pollution, and climate change. In order to control greenhouse gas emissions, particularly CO2, fossil fuels must be replaced by eco-friendly fuels such as biomass. The use of renewable energy sources is becoming increasingly necessary. The biomass resources are the most common form of renewable energy. The conversion of biomass into energy can be achieved in a number of ways. The most common form of converted biomass is pellet fuels as biofuels made from compressed organic matter or biomass. Pellets from lignocellulosic biomass has compared to conventional fuels with a relatively low bulk and energy density and a low degree of homogeneity. Thermal pretreatment technology like torrefaction is applied to improve fuel efficiency of lignocellulosic biomass, i.e., less moisture and oxygen in the product, preferrable grinding properties, storage properties, etc.. During torrefacton, lignocelluosic biomass such as palm kernell shell (PKS) and empty fruit bunch (EFB) was roasted under an oxygen-depleted enviroment at temperature between 200 and $300^{\circ}C$. Low degree of thermal treatment led to the removal of moisture and low molecular volatile matters with low O/C and H/C elemental ratios. The mechanical characteristics of torrefied biomass have also been altered to a brittle and partly hydrophobic materials. Unfortunately, it was much harder to form pellets from torrefied PKS and EFB due to thermal degradation of lignin as a natural binder during torrefaction compared to non-torrefied ones. For easy pelletization of biomass with torrefaction, pellets from PKS and EFB were manufactured before torrefaction, and thereafter they were torrefied at different temperature. Even after torrefaction of pellets from PKS and EFB, their appearance was well preserved with better fuel efficiency than non-torrefied ones. The physical properties of the torrefied pellets largely depended on the torrefaction condition such as reaction time and reaction temperature. Temperature over $250^{\circ}C$ during torrefaction gave a significant impact on the fuel properties of the pellets. In particular, torrefied EFB pellets displayed much faster development of the fuel properties than did torrefied PKS pellets. During torrefaction, extensive carbonization with the increase of fixed carbons, the behavior of thermal degradation of torrefied biomass became significantly different according to the increase of torrefaction temperature. In conclusion, pelletization of PKS and EFB before torrefaction made it much easier to proceed with torrefaction of pellets from PKS and EFB, leading to excellent eco-friendly fuels.

Breathing Reserve Index at Anaerobic Threshold of Cardiopulmonary Exercise Test in Chronic Obstructive Pulmonary Disease (만성폐쇄성 폐질환의 운동부하 심폐기능검사에서 무산소역치 예비호흡지수의 의의)

  • Lee, Byoung-Hoon;Kang, Soon-Bock;Park, Sung-Jin;Jee, Hyun-Suk;Choi, Jae-Chol;Park, Yong-Bum;Ahn, Chang-Hyuk;Kim, Jae-Yeol;Park, In-Won;Choi, Byung-Whui;Hue, Sung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.6
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    • pp.795-802
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    • 1999
  • Objective : Cardiopulmonary exercise test is a useful tool to evaluate the operative risk and to plan exercise treatment for the patients with chronic obstructive pulmonary disease(COPD). In cardiopulmonary exercise test, most of the measured parameters are recorded at the time of peak exercise, which are hard to attain in COPD patients. So we evaluated the usefulness of the parameter, breathing reserve index(BRI=minute ventilation [$V_E$]/maximal voluntary ventilation[MVV]) at the time of anaerobic threshold($BRI_{AT}$) for the differentiation of COPD patients with normal controls. Methods : Thirty-six COPD patients and forty-two healthy subjects underwent progressive, incremental exercise test with bicycle ergometer upto possible maximal exercise. All the parameters was measured by breath by breath method. Results : The maximal oxygen uptake in COPD patients (mean$\pm$SE) was $1061.2{\pm}65.6ml/min$ which was significantly lower than $2137.6{\pm}91.4ml/min$ of normal subjects(p<0.01). Percent predicted maximal oxygen uptake was 54.3% in COPD patients and 86.0% in normal subjects(p<0.01). Maximal exercise(respiratory quotient; $VCO_2/VO_2{\geq}1.09$) was accomplished in 7 of 36 COPD patients(19.4%) and in 18 of 42 normal subjects(42.9%). The $BRI_{AT}$ of COPD patients was higher($0.50{\pm}0.03$) than that of control subject($028{\pm}0.02$, p<0.01), reflecting early hyperventilation in COPD patient during exercise. The correlation between $BRI_{AT}$ and BRI at maximal exercise in COPD patients was good(r=0.9687, p<0.01). Conclusion : The $BRI_{AT}$ could be a useful parameter for the differentiation of COPD patients with normal controls in the submaximal cardiopulmonary exercise test.

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Radiation-Induced Apoptosis of Lymphocytes in Peripheral Blood (말초혈액 내 림프구의 방사선에 의한 아포프토시스)

  • Oh, Yoon-Kyeong;Lee, Tae-Bum;Nam, Taek-Keun;Kee, Keun-Hong;Choi, Cheol-Hee
    • Radiation Oncology Journal
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    • v.21 no.1
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    • pp.75-81
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    • 2003
  • Purpose : This study quantitatively evaluated the apoptosis In human peripheral blood lymphocytes using flow cytometry, and investigated the possibility of using this method, with a small amount of blood, and the time and dose dependence of radiation-induced apoptosls. Materials and Methods : Peripheral blood lymphocyes were isolated from the heparinized venous blood of 11 healthy volunteers, 8 men and 3 women, with each 10 ml of blood being divided Into IS samples. The blood lymphocytes were Irradiated using a linear accelerator at a dose rate of 2.4 Gy/min, to deliver doses of 0.5, 1, 2 and S Gy. The control samples, and Irradiated cells, were maintained in culture medium for 24, 48 and 72 hours fellowing the Irradiation. The number of apoptotic cells after the in vitro X-irradiation was measured by flow cytometry after Incubation periods of 24, 48 and 72 hours. We also observed the apoptotic cells using a DNA fragmentation assay and electron microscopy. Results : The rate oi spontaneous apoptosis increased in relation to the time interval following irradiation (1.761 ${\pm}$0.161, 3.563${\pm}$0.554, 11.098${\pm}$2.849, at 24, 48, and 72 hours). The apoptotli cells also increased In the samples irradiated with 0.5, 1, 2 and 5 Gy, In a radiation dose and time interval after Irradiation manner, with the apoptosls being too great at 72 hours after Irradiation. The dose-response curves were characterized by an Initial steep Increase In the number of apoptotic cells for Irradiation doses below 2 Gy, with a flattening of the curves as the dose approached towards 5 Gy. Conclusion :The flow cytometric assay technique yielded adequate data, and required less than 1 mL of blood. The time and dose dependence of the radiation-induced apoptosis, was also shown. It is suggested that the adequate time Interval required for the evaluation of apoptosis would be 24 to 48 hours after blood sampling.

Manufacturing and Characteristics of Fruit Wine from Acanthapanax sessiliflorus (오가피 열매 발효주의 제조 및 특성)

  • Choi, Jae-Myoung;Kim, Kwang-Yup;Lee, Sang-Hwa;Ahn, Jun-Bae
    • Food Engineering Progress
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    • v.14 no.1
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    • pp.1-6
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    • 2010
  • Fruit wine from Acanthopanax sessiliflorus(A. sessiliflorus) including many pharmacological components was manufactured and its functional properties were investigated. The fruit part of A. sessiliflorus contained 75.74${\pm}$0.49%(w/w) moisture, 12.51${\pm}$1.23%(w/w) crude protein, 4.20${\pm}$0.51.%(w/w) crude fat and 5.21${\pm}$1.64%(w/w) crude ash. Minerals of fruit were potassium(12.94${\pm}$0.08 mg/g), calcium(1.53${\pm}$0.06 mg/g) and magnesium(1.12${\pm}$0.05 mg/g). Initial soluble solid and fermentation temperature were 24-30$^{\circ}$Brix and 20${^{\circ}C}$ for manufacturing fruit wine from A. sessiliflorus. When initial soluble solid of a must was adjusted to more than 30$^{\circ}$Brix, ethanol production was suppressed slightly. The polyphenol content of the fruit wine fermented at 20${^{\circ}C}$(125.24${\pm}$1.86 mg/mL) was higher than those at 25${^{\circ}C}$(99.69${\pm}$2.11 mg/mL) and 30${^{\circ}C}$(95.55${\pm}$1.54 mg/mL). Electron donating activities of wines fermented at 20, 25 and 30${^{\circ}C}$ were 85.9${\pm}$2.3, 55.7${\pm}$2.5 and 55.2${\pm}$3.4%, respectively. The content of eleutheroside B increased up to 146.58${\pm}$4.10 $\mu$g/mL during fermentation. There was no significant effect of fermentation temperature on eleutheroside B content. The fruit part of A. sessiliflorus can be used as a valuable resource for development of nutraceutical foods.

Acoustic Characterization of Three Seamounts Located in the Northwest of Marshall Islands, Western Pacific (서태평양 마샬제도 북서쪽에 위치한 세 해저산에 대한 음향상 연구)

  • Lee, Tae-Gook;Lee, Kie-Hwa;Moon, Jai-Woon;Jung, Mee-Sook;Kim, Hyun-Sub;Lee, Sang-Mook
    • Journal of the Korean Geophysical Society
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    • v.7 no.3
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    • pp.193-206
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    • 2004
  • Geophysical data including chirp (3 7 kHz) subbottom profile and detailed bathymetry were obtained over three seamounts in the Ogasawara Fracture Zone (OFZ) of the western Pacific, as a part of manganese crust survey onboard R/V Onnuri in 2003. The OFZ is a 150-km-wide, 600-km-long rift zone, which separates the East Mariana and Pigafetta Basin. The OFZ is unique in that it includes many seamounts (e.g., Magellan Seamounts andseamounts on the Dutton Ridge). The sub-seafloor acoustic echoes obtained near the OFZ were classified into following types on the basis of their characteristics: types I-1(pelagic sediment with parallel or subparallel reflectors), I-2 (pelagic sediment with no internal reflectors), and III-1 (reef build-up complex) on summit; types II-1 and III-2 (basement outcrop) on flank rift zone and upper slope, respectively; type III-3 (slump) on the lower slope and embayment between the flank rift zones; types II-2 (debrite) on the base of slope and basin floor; and types II-3 (turbidite or pelagic sediment) and II-4 (turbidite) on the basin floor. The mass-wasting that produced the complex of type II-2 debrite and III-3 slump on the lower slope and basin may have been caused by (1) strong tensional stress in the OFZ which may cause the numerous fissures or basement faults and (2) complex of the faults on the summit and steep upper slope. The variations in the echo type of pelagic sediment in the summit of seamounts may be related with the changes in the depositional and/or erosional environments. Type I-2 pelagic sediment, which is characterized by a thin and intermittent coverage, was probably deposited at a sheltered area when the current was strong, whereas type I-1 pelagic deposit occurred during a stage of progressive sedimentation.

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