• Journal of Environmental Science International
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• v.10 no.1
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• pp.41-45
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• 2001

This study was carried out to investigate phytoplankton community structure in the Naktong river from January to December in 1999. In water quality, average value of pH were 8.1, BOD 2.5mg/$\ell$, COD 5.0mg/$\ell$, Chl-a 41$\mu\textrm{g}$/$\ell$, and $NH_4^+-N$ 0.08mg/$\ell$, respectively. Phytoplankton were identified 42 genera 76 species. Among these, diatoms were 39 species(51.3%), green algae 25 species(32.9%), cyanobacteria 4 species(5.3%), dinoflagellates 4 repectively. The highest standing crops were 33,023 cells/$m\ell$ in February at the Mulgum and the lowest 79 cells/$m\ell$ in March at the Goryung. Also, Standing crops were increased with proceeding from middle part to lower part. Seasonal succession of phytoplankton represented that Stephanodiscus hantzschii was dominant species in winter, Cyclotella menaghiniana and Synedra acus in spring, C. meneghiniana, S. acus, Aulacoseira granulata var. angustissima in summer, and A. granulata var. angustissima and C. meneghiniana in autumn. Ecological important species were 4 species, that are Stephanodiscus hantzschii, Cyclotella meneghiniana, Synedra acus, and Aulacoseira granulata var. angustissima. In the community analysis, dominance indices ranged from 0.434(August, Namji) to 0.999(January, February, Mulgum) and diversity indices from 0.026(February, Mulgum) to 3.073(September, Namji). According to the similarity index among the stations, it was generally defind as two areas such as middle(Goryung, Namji and Samryangjin) and lower part(Mulgum).

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1288-1292
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• 1999

The physicochemical properties and palatability of Hanwoo(cow, steer, and bull) beef loin(1＋ carcass grade) were studied. pH(5.56~5.69), moisture content(67.6~69.0%), crude protein content(17.8~18.7%), and crude fat content(11.9~13.8%) of Hanwoo beef loin did not show significant difference between the types of Hanwoo. L(44.5~46.9), a(19.9~20.6), and b(10.3~11.6) color parameters, water holding capacity (69.4~70.5%), volatile basic nitrogen content(9.86~11.28mg%), thiobarbituric acid value(0.148~0.158 mg malonaldehyde/kg), and cooking loss(26.3~27.9%) of beef loin did not show significant difference between the types of Hanwoo either. Hardness, myofibrillar fragmentation index(MFI), and chewiness of beef loin were 6.1~6.9 dyne/cm2, 50.3~54.9, and 39.5~ 52.0g, respectively. No differences were found in hardness and MFI between the types of Hanwoo, while chewiness of cow was much lower than that of steer and bull(p<0.05). Cow was the best in palatability.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.464-472
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• 2017

The qualities of rice cooked on heat plate, induction heat and heat plate with pressure, were investigated. The weight, volume, water soluble index (WSI), hydration by SEM (Scanning Electron Microscope), and gelatinization by DSC (Differential Scanning Calorimetry), as well as the consumer acceptability of cooked rice were analyzed. The weight, volume and WSI of rice cooked on heat plate with pressure were higher than those of rice cooked on heat plate and induction heat. The rice cooked on heat plate with pressure also showed higher degree of hydration and gelatinization, and lower degree of enthalpy of gelatinization than the rice cooked on heat plate and induction heat for 5~15 min. The consumer acceptability revealed that the odor, appearance, taste, texture and overall acceptance of rice cooked on induction heat were better than those of rice cooked on heat plate and heat plate with pressure. During storage in a cooker for 0~12 h, there was a decrease in the consumer acceptability of cooked rice. Overall results indicate that the qualities of rice cooked on induction heat and heat plate with pressure were higher than those of rice cooked on heat plate.

• Journal of the Korean Society of Food Culture
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• v.33 no.1
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• pp.62-69
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• 2018

The purpose of this study was to investigate the antioxidative and physical properties of finger food type rice snacks and pumpkin rice snacks for infants aged 6 to 12 months old. The addition of rice germ did not affect density or porosity, and there was no significant difference when compared with commercial products. The addition of rice germ to the rice snack group did not reduce the longitudinal expansion quality of the rice snack. The WAI of RW and SW values were 9.83 and 8.93, respectively, which were significantly higher than those of other samples (p<0.05). The results of this study show that the addition of rice germ to rice snack resulted in reduced density and porosity of rice snacks and maintenance of a high water absorption index, which are more desirable characteristics for products. The products with rice germ showed significantly higher antioxidative activities among all samples (p<0.05).

• Geomechanics and Engineering
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• v.14 no.4
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• pp.399-406
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• 2018

The influences of mineral content and porosity on ultrasonic wave velocity were assessed for ten hornfelsic rocks collected from southern and western parts of the city of Hamedan, western Iran. Selected rock samples were subjected to mineralogical, physical, and index laboratory tests. The tested rocks contain quartz, feldspar, biotite, muscovite, garnet, sillimanite, kyanite, staurolite, graphite and other fine grained cryptocrystalline matrix materials. The values of dry unit weight of the rocks were high, but the values of porosity and water absorption were low. In the rocks, the values of dry unit weight are related to the presence of dense minerals such as garnet so not affected by porosity. The statistical relationships between mineral content, porosity and ultrasonic wave velocity indicated that the porosity is the most important factor influencing ultrasonic wave velocity of the studied rocks. The values of P-wave velocity of the rocks range from moderate to very high. Empirical equations, relevant to different parameters of the rocks, were proposed to determine the rocks' essential characteristics such as primary and secondary wave velocities. Quality indexes (IQ) of the studied samples were determined based on P-wave velocities of them and their composing minerals and the samples were classified as non-fissured to moderately fissured rocks. Also, all tested samples are classified as slightly fissured rocks according to the ratio of S-wave to P-wave velocities.

• Ocean and Polar Research
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• v.29 no.4
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• pp.319-326
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• 2007

Coastal marine ecosystems continue to suffer unrelenting pressures from human population growth, increased development, and climate change. Moreover, these systems' capacity for self-repair is declining with such increases in anthropogenic production of various pollutants. What is the present health status or condition of the coastal ecosystem? If our coastal areas are unhealthy, which conditions are considered serious? To answer such questions, the United States, Canada, and Australia are currently assessing coastal ecosystem health using systematic monitoring programs as well as identifying and implementing management plans to improve the health of degraded coastal ecosystems. To evaluate marine environments, Korea is currently using a limited number of factors to estimate water quality. In fact, we are ill-prepared for assessing coastal ecosystem health because no biologically specific criteria are in place to measure the responses to various pollutants. We should select ecosystem-specific indicators from physicochemical stressors and evaluate the subsequent biological responses within each ecosystem. Furthermore, a set of practical indicators should be generated by considering the characteristics and uses of a local coastal area and the key issues at hand. The values of indicators should be presented as indices that allow understanding by the general public as well as by practitioners, policy makers, environmental managers and other stakeholders.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.207-213
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• 1998

These experiments were carried out to investigate the effects of electrical stimulation(ES) and delayed chilling (DC) on the quality characteristics of Hanwoo beef. The left half carcass was treated with ES(550V, 90sec)within postmortem 30min. The electrical stimulated half carcass was subjected to chilling at 16$^{\circ}C$ for 24hr, and then stored at 2$\pm$2$^{\circ}C$ for 15days (ESDC). The right half carcass was stored at 2$\pm$2$^{\circ}C$ for 15 days (NES). ESDC showed a rapid pH fall and tended to reach to pH5.54 at postmortem 2 hrs. But, there was no consistent effect of electrical stimulation and delayed chilling on meat color, cooking loss and water holding capacity. Myofibril fragmentation index was higher than that of NES during storage. ESDC showed lower shear force value and strength consistently than NES. SDS-PAGE band patterns of myofibrils showed the rapid breakdown of troponin T and troponin I band in ESDC, compared with NES, and revealed the specific band below myosin light chain-2 pattern in ESDC.

• Preventive Nutrition and Food Science
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• v.12 no.1
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• pp.40-45
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• 2007

The effects of drying methods on the physicochemical properties of chaga (Inonotus obliquus) mushroom powder were investigated. Scanning electron micrograph revealed that freeze drying produced smaller particle- sized samples which in turn resulted in higher porosity than did vacuum and hot-air drying. Samples prepared by freeze drying showed a significantly higher L*-value as compared with those prepared by hot-air drying and vacuum drying (p<0.05). The lightness (L*-value) significantly decreased with increasing relative humidity and storage temperature regardless of drying method (p<0.05). The yellowness (b*-value) increased significantly with increasing relative humidity (p<0.05). Browning index was significantly lower in samples prepared by freeze drying (p<0.05) but not significantly different between samples dried by hot-air and vacuum drying. Freeze dried sample exhibited a significantly higher degree of rehydration than other samples (p<0.05) probably due to the small particle size. Water solubility of the freeze dried sample was higher than those of the other methods while swelling ratio of the same sample appeared to be lower than those of others. Freeze dried chaga mushroom powder contained significantly lower amount of total phenolics and total sugar as compared to other samples (p<0.05).

• Journal of the Korean Society of Safety
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• v.7 no.3
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• pp.22-29
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• 1992

Emulsion-type cometics contain many kinds of carbon and energy source i.e., vegetable oil, mineral oil and carbohydrate etc., those can be used as nutrients and caused contamination by microbials. Thereby we have to keep cosmetics from the possibility of contamination by microbials. From this viewpoint, the purpose of this study is to get the data necessary not only to prevent dermatopathia occurred by microbials but also to sustain the quality. In this experiment, we observed how many Staphylococcus aureus were grown in the prepared cosmetics with or without antiseptics so as to prevent contamination. When the contamination proceed, the stability of phase was disturbed and creaming phenomina was happened with some discoloration and bad smell. About 40 days after, the pH was changed from 7.6 to 6.5 and the refractive index of cosmetic raw materials were changed from 1.4415 to 1.4490(water : oil=70:30). By adding antiseptics Into prepared cosmetics, the number of Staphylococcus aureus with challenge test method were decreased to 7$\times$103 cell/ml. For the antibacterial effect against Staphylococcus aureus, p-hydroxy benzoic acid propyl ester in phosphoric acid buffer solution was the best.

• Journal of Environmental Science International
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• v.31 no.4
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• pp.295-309
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• 2022

The purpose of this study was to evaluate the operational characteristics of wastewater treatment using Sequencing Batch Reactor (SBR) with Aerobic Granular Sludge (AGS) separator in the pilot plant. Pilot plant experiments were conducted using SBR with AGS separator and pollution removal efficiencies were evaluated based on the operational condition and surface properties of AGS. The results of the operation on water quality of the effluent showed that the average concentration of total organic carbon, suspended solids, nitrogen, and phosphorus was 6.89 mg/L, 7.33 mg/L, 7.33 mg/L, and 0.2 mg/L, respectively. All these concentrations complied the effluent standard in Korea. The concentration of mixed liquor suspended solid (MLSS) fluctuated, but the AGS/MLSS ratio was constant at 86.5±1.3%. Although the AGS/MLSS ratio was constant, sludge volume index improved. These results suggested that the particle discharged fine sludge and increased the AGS praticle size in the AGS. Optical microscopy revealed the presence of dense AGS at the end of the operation, and particles of > 0.6 mm were found. Compared to those of belt-type AGS separator, the required area and power consumption of the hydrocyclone-type AGS separator were reduced by 27.5% and 83.8%, respectively.