• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.114-121
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• 2002

A correction index of catchability (CIC) was derived using a 6 year research data set to examine the seasonal variation in catchability for the night time prawn fishery in Albatross Bay. CIC reflects the composite effect of the monthly variation in size selectivity, emergence­burying behaviour and population density variation of prawn populations. The values of CIC for four dominant species, Metapenaeus endeavouri, M. ensis, Penaeus semisulcatus and P. esculentus, were examined. The value of CIC for M. endeavouri varied substantially and was the highest in August. The values of CIC for M. ensis were high during November to March and the seasonality was weaker than that for M. endeavouri. The monthly variation in CIC for P. semisulcatus reflected the seasonal variation in population density, being high during November to February. These results suggest that the catch ability of P. esculentus is steady throughout the year but it varies greatly on a seasonal basis for M. endeavouri.

• Transactions on Electrical and Electronic Materials
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• v.13 no.2
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• pp.69-72
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• 2012

In this study, deposition of low-dielectric constant SiOC(H) films by conventional plasma-enhanced chemical vapor deposition (PECVD) were investigated through various characterization techniques. The results show that, with an increase in the plasma power density, the relative dielectric constant (k) of the deposited films decreases whereas the refractive index increases. This is mainly due to the incorporation of organic molecules with $CH_3$ group into the Si-O-Si cage structure. It is as confirmed by FT-IR measurements in which the absorption peak at 1,129 $cm^{-1}$ corresponding to Si-O-Si cage structure increases with power plasma density. Electrical characterization reveals that even after fast thermal annealing process, the leakage current density of the deposited films is in the order of $10^{-11}$ A/cm at 1.5 MV/cm. The reliability of the SiOC(H) film is also further characterized by using BTS test.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.521-526
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• 2007

Density functional calculations have been performed for the reactions of perfluoroalkylsilane and alkylsilane with silica surfaces. The (100) and (111) surfaces of ${\beta}-cristobalite$ are used as two possible models of the hydroxylated amorphous silica surface. This is the crystalline phase of silica with density and refractive index closest to those of amorphous silica. Moreover, two ${\beta}-cristobalite$ surfaces have the two types of silanol groups, namely the single silanols and the geminal silanols. We investigate the possible adsorption structure and formation energy of perfluoroalkylsilane and alkylsilane molecules with two type of silanol groups. The results will be compared with cluster and slab model.

• Ocean and Polar Research
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• v.24 no.4
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• pp.359-365
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• 2002

The qualitative and quantitative composition of the phytoplankton of the coastal waters off Vladivostok during the period 1991-1994 was studied. The following trends in the phytoplankton composition with decreasing distance from the source of eutrophication were revealed: 1) total density and bio-mass increased; 2) the density of the diatom Skeletonema costatum, which reflects a decrease in the Shannon-Weaver species diversity index during the summer microalgal bloom, increased significantly; and 3) the density of the non-diatom component of the phytoplankton increased.

• Journal of Environmental Science International
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• v.12 no.8
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• pp.861-870
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• 2003

Using a simple continuous optical technique, coupled with measurements of zeta potential, the effects of polyelectrolyte dosage, kaoline particles and pH on flocculation of humic acid by several cationic polyelectrolytes, have been examined. The charge density of a polyelectolyte is important in determining the optimum dosage and in the removal of humic acid. The optimum dosage is less for the polyelectrolytes of higher charge density and is the same regardless of the presence of kaoline particles of different turbidity. At the dosage, the removal of humic acid is higher for the polyelectrolytes of higher charge density and the zeta potential of humic acid approaches to near zero, With increasing pH of humic acid, the optimum dosage increases and the flocculation index value obtained at the dosage decreases in the following pH 7 ＞ pH 5 ＞ pH 9, regardless of polyelectrolytes.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.168-172
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• 2008

The flame retardancy by the addition of clay was evaluated to present as the fundamental data to decrease the fire hazard of polymers and life losses. The flame retardancy was examined to increase flame retardancy and to decrease smoke yield of epoxy by the addition of clay such as montmorillonite. For this study, the experiments of flame retardancy were conducted as follows : the measurement of the limiting oxygen index(LOI), char yield, and smoke density. As MMT concentration increased, epoxy/MMT composite increased LOI and char yield with the decreased smoke density.

• Journal of the Korean Dietetic Association
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• v.12 no.1
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• pp.10-17
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• 2006

The purpose of this study was to examine the correlation between nutrient intakes and bone mineral density in female university students. A total 27 female university students were measured the anthropometric characteristics, dietary intake and the bone mineral density of carpus using DEXA. The average age, height, weight, % body fat, WHR, and BMI of the subjects were 22.7 years, 161.5 cm, 57.0 kg, 29.9%, 0.8, 21.8 kg/$m^2$, respectively. Bone mineral density of ultradis and distal carpus as T-value were -1.5 and -0.4, respectively. The daily energy intake of the subjects was 1589.0kcal. And the intakes of energy, calcium, iron, zinc, vitamin $B_2$, and folic acid did not meet the Korean RDAs. The daily total food intake of the subjects was 1011.0g and food intake from cereals and vegetables was high. The major food groups of mineral intake were vegetables/cereals/milks/fishes for calcium, cereals/meat/vegetables/fishes for phosphorus, cereals/vegetables/meats for iron, seasonings/vegetables/cereals for sodium, vegetables/cereals/seasonings for potassium, and cereals/meats for zinc. The body weight and body mass index were significantly positive correlated to the bone mineral density of average carpus, respectively. The intakes of animal calcium and vitamin $B_2$ were significantly negative correlated to the bone mineral density of average carpus, respectively. In conclusion, bone mineral density in carpus and nutrient intakes of some female university students were low. Therefore, health management and the study on relation between bone mineral density in various site and long-term intakes of nutrients in many subjects are required.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.548-554
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• 2016

Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.243-251
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• 2010

Evapotranspiration and rainfall-runoff are the major components of hydrological cycle and thereby the changes of them can directly affect the wetness/dryness or runoff characteristics of basins. In this study the wetness/dryness in Geum river basin are classified by dint of cumulative probability density function of monthly moisture index and the long term changes of them are analyzed based on climatic water balance concept. The drought events in Geum river basin are selected through evaluation of monthly moisture index and the various hydrological properties of them are investigated in detail. Also the trends of time-series of climatic water balance components are examined by Seasonal Kendall test and the variability of hydrological cycle in Geum river basin during the recent decade is inquired. It is judged that the results of this study can be contributed to establishment of the counter plan against the future drought events as the fundamental information.

• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.1046-1050
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• 2004

Six physical properties (enthalpy, density, decomposition temperature, solubility in water, pKa values, and hydronium potential) were examined by molecular modeling techniques. The molecular connectivity index, Wiener distance index, and Ad hoc descriptor are employed as structural parameters to encode information about branching, size, cyclization, unsaturation, heteroatom content, and polarizability. This paper examines the correlation of the molecular modeling techniques parameters and the physicochemical properties of amino acids. As a results, calculated values were in agreement with experimental data in the above six physical properties of amino acids and the molecular connectivity index was superior to the other indices in fitting the calculated data.