• Title/Summary/Keyword: ice thickness

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Seasonal Variations of Settling Particles and Metal Fluxes at a Nearshore Site of Marian Cove, King George Island, Antarctica (남극 킹조지섬 마리안소만에서 침강 입자와 금속 플럭스의 계절 변화)

  • Shim, Jeong-Hee;Kang, Young-Chul;Han, Myung-Woo;Kim, Dong-Seon;Chung, Ho-Sung;Lee, Sang-Hoon
    • Ocean and Polar Research
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    • v.24 no.2
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    • pp.123-134
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    • 2002
  • Seasonal variations of settling particles and metal fluxes were monitored at a nearshore site of Marian Cove, King Geroge Island, Antarctica from 28th February 1998 to 22nd January 2000. Near-bottom sediment traps were deployed at 30m water depth of the cove, and sampling bottles were recovered every month by SCUBA divers. Total particulate flux and metal concentrations were determined from the samples. Total particulate flux showed a distinct seasonality, high in austral summer and low in austral winter: the highest flux $(21.97g\;m^{-2}d^{-1})$ was found in February of 1999, and the lowest $(2.47g\;m^{-2}d^{-1})$ in September of 1998, when sea surface was frozen completely. Lithogenic particle flux accounted for 90% of the total flux, and showed a significantly negative correlation with the thickness of snow accumulation around the study site. It was suggested that the most of the lithogenic particles trapped in the bottles was transported by melt water stream from the surrounding land. Fluxes of Al, Fe, Ti, Mn, Zn, Cii, Co, Ni, Cr, Cd, and Pb showed similar seasonal variations with the total flux, and their averaged fluxes were 34000, 9000,960, 180, 13.8, 17.6, 3.0,2.1, 5.4, 0.02, and $1.5nmol\;m^{-2}d^{-1}$ respectively. Among the metals, Cu and Cd showed the most noticeable seasonal patterns. The Cd flux correlated positively with the fluxes of biogenic components while the Cu flux correlated with both the lithogenic and biogenic particle fluxes. The Cu flux peak in the late summer is likely related to a substantial amount of inflow of ice melt water laden with Cu-enriched lithogenic particles. On the other hands, the Cd flux peak in the early spring may be associated with the unusually early occurred phytoplankton bloom.

Study on Meat Tenderness of a Pretense Extracted from Domestic Pear (국산배에서 추출한 단백질 분해효소의 식육 연화제로서의 활용에 관한 연구)

  • Han Seung K.;Chin Koo B.
    • Food Science of Animal Resources
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    • v.24 no.4
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    • pp.326-328
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    • 2004
  • Domestic pear has been reported that it contained a pretense, which used for tenderizer of meat, however no researches for optimum level of the enzyme with maximum tenderness effect have been studied. Thus, this study was peformed to determine the optimum level of a protease for meat tenderness. Moisture contents (%) of domestic pears was determined. A pretense was homogenized in a mixer and centrifuged at 10,000 G for 1hr. After taken the supernatant, dialysis was conducted to remove salts and sugars, and freeze-dried. Then, various level (0.05, 0.1 and 0.2%) of the purified pretense were added to pork loins (3cm thickness). Then, pork samples were boiled at 80 for 12 min in a water bath to reach the interval temperature of 71 and chilled in an ice. Moisture contents (%) of domestic pears ranged from 87.2 and 87.8%. No differences in cooking loss of pork meats were observed (p>0.05) among various levels of a pretense. After centrifugation, the protein concentrations of a protease showed from 5.96 $\mu\textrm{g}$/fmL to 7.25 $\mu\textrm{g}$/mL. Increased level of a pretense up to 0.1% reduced (p<0.05) the shear value (kg/g), however no further reduction of shear value was observed at the level of higher than 0.1% of the purified pretense. The approximate molecular weight of the pretense analysed by sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was 30 kDa. These results suggest that the optimum level of a pretense for the maximum effect of meat tenderness is above 0.1%. Further research will be peformed to determine the effect of various domestic pears and ingredients, such as salt and phosphate, on meat tenderness.

Analysis of Empirical Multiple Linear Regression Models for the Production of PM2.5 Concentrations (PM2.5농도 산출을 위한 경험적 다중선형 모델 분석)

  • Choo, Gyo-Hwang;Lee, Kyu-Tae;Jeong, Myeong-Jae
    • Journal of the Korean earth science society
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    • v.38 no.4
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    • pp.283-292
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    • 2017
  • In this study, the empirical models were established to estimate the concentrations of surface-level $PM_{2.5}$ over Seoul, Korea from 1 January 2012 to 31 December 2013. We used six different multiple linear regression models with aerosol optical thickness (AOT), ${\AA}ngstr{\ddot{o}}m$ exponents (AE) data from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Terra and Aqua satellites, meteorological data, and planetary boundary layer depth (PBLD) data. The results showed that $M_6$ was the best empirical model and AOT, AE, relative humidity (RH), wind speed, wind direction, PBLD, and air temperature data were used as input data. Statistical analysis showed that the result between the observed $PM_{2.5}$ and the estimated $PM_{2.5}$ concentrations using $M_6$ model were correlations (R=0.62) and root square mean error ($RMSE=10.70{\mu}gm^{-3}$). In addition, our study show that the relation strongly depends on the seasons due to seasonal observation characteristics of AOT, with a relatively better correlation in spring (R=0.66) and autumntime (R=0.75) than summer and wintertime (R was about 0.38 and 0.56). These results were due to cloud contamination of summertime and the influence of snow/ice surface of wintertime, compared with those of other seasons. Therefore, the empirical multiple linear regression model used in this study showed that the AOT data retrieved from the satellite was important a dominant variable and we will need to use additional weather variables to improve the results of $PM_{2.5}$. Also, the result calculated for $PM_{2.5}$ using empirical multi linear regression model will be useful as a method to enable monitoring of atmospheric environment from satellite and ground meteorological data.

A Study on Health Condition and Nutritional Status of Female University Students in Masan Area (마산시 일부 여대생의 건강상태 및 영양섭취 실태 조사)

  • Park, Eun-Ju;Cheong, Hyo-Sook;Shin, Dong-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.9
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    • pp.1501-1514
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    • 2004
  • The purpose of this study was to evaluate the health condition and nutritional status in female university students in Masan. The 285 subjects aged 20.1 years (18~26 years) were assessed with a set of questionnaire composed of general information, food, smoking, drinking and exercise habits, anthropometric measurements, blood pressure measurements, 24-hour recall and food frequency questionnaire. The rates of smoking and alcohol drinking habits were 1.8% and 82.5%, respectively. All the subjects had the experience of passive smoking. The 11% of the students exercised regularly and 11.6% ate meal regularly. The average height and weight of subjects were 161.0 ㎝ and 53.9 ㎏, respectively and the BMI was calculated as 20.8${\pm}$2.6 ㎏/$m^2$:The 13.3% of subjects were underweight, while 6.7% of them were overweight. The mean value for body fat was 26.4% and subscapular and tricep skinfolds thickness were 14.2 ㎜ and 16.9 ㎜, and waist-hip ratio was 0.72. The systolic/diastolic blood pressure of the subjects was 115.9 ㎜Hg/70.9 ㎜Hg. Except protein, phosphorous, vitamin E, B_6 and C, the average intakes of energy and nutrients were below the Korea recom-mended dietary allowance (RDA). Especially, intakes of calcium, iron and zinc were the lowest, as <70% of RDA. The proportion of energy derived from carbohydrates : protein : fat was 58.0 : 15.8 : 26.2. The 10 frequently consumed food were ssalbap (47.2/mon), kimchi (35.6/mon), onion (16.8/mon), japgokbap (15.1/mon), sesame oil (14.1/mon), carbonated drink (13.3/mon), grapes (12.7/mon), ice cream (12.4/mon), milk (11.9/mon) and water-melon (10.6/mon). Results of this study could be useful for planning nutrition education programs for female university students in this area to improve their dietary habit and health status.

Trans Fatty Acid Isomers of Processed Foods Commonly Consumed in Korea (한국인 상용 가공식품의 trans 지방산 이성체)

  • 노경희;원미숙;송영선
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.3
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    • pp.325-337
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    • 2003
  • This study was designed to determine the distribution of trans fatty acids (tFAs) isomers of Processed foods commonly consumed in Korea. The tFAs positional isomers were analyzed using GC/MS spectrometer with HP-23 cis/trans FAME, capillary column (50m $\times$ 0.20 mm, id., 0.2 ${\mu}{\textrm}{m}$ film thickness) for 41 food samples. TFAs isomers were identified by comparing retention time with standards and GC/MS spectrum. In margarines, the content of tFAs ranged from 4.0% to 25.16% and the most abundant positional isomer of tFAs was C18:1 $\Delta$9t. In oils and fats, lards contained higher levels of tFAs (5.70~16.54%) than shortenings (6.77~10.55%). Shortenings contained higher levels of C18:1 $\Delta$9t (3.1~5.1%) than lard (1.6~4.3%), but corn oils had no tFAs. In seasonings, mayonnaise had no C16:1 $\Delta$9t, whereas C18:3t was detected. The content of tFAs in confectioneries was wide (16.20~52.16%). Among them, instant popcorns contained the highest amount of tFAs. Milk and dairy products showed even distribution of tFAS such as C18:1t, C18:2t, and C18:3t. Predominant tFAS isomer of condensed milk and ice cream was C16:1 $\Delta$9t. Frozen french fries and fried chicken contained higher levels of C18:1$\Delta$9t (9.4%), whereas grilled pork (jowl) had no C18:1 $\Delta$9t. The amount of tFAs per serving size was the highest in popcorn, followed by frozen pizza, frozen french fries, fried chicken, and bakeries.