• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.83-93
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• 2005

Research was initiated to investigate turf performance under USGA soil system. USGA system 45 centimeters deep was built with rootzone layer, intermediate layer, and drainage layer. Six turfgrass entries were comprised of 3 blends and 3 mixtures from cool-season grasses (CSG). Turfgrass color and quality ratings were best in spring and fall, especially early May to early July and late August to early November. Kentucky bluegrass (KB) consistently produced the greatest performance, while perennial ryegrass (PR) the poorest. Intermediate turf performance between KB and PR was observed with tall fescue (TF). Among CSG mixtures it increased with KB but decreased with PR. There were considerable variations in summer turf Performance. No summer drought injury was found in KB and TF. However, PR showed poor performance through summer as compared with others. Among mixtures, it decreased with PR. It was suggested that PR mix in less than $20\%$ in the mixtures to have an acceptable quality in summer. Cultural intensity also affected it. With lowering mowing height, KB of rhizomatous-type in growth habit kept good quality, while PR and TF with bunch-type in growth habit poor quality. Mowing quality was greatly different among CSG. KB produced clean-cut surface, but PR unclean one. If had an intermediate mowing quality between KB and PR. A great difference in green color retention was observed among CSG. The longest CSG was PR that kept green for 339 days, while the shortest one TF for 267 days. KB continued to keep green for 290 days. The mixtures kept green in color for 292 to 315 days, depending on turfgrass mixing intensity. The greater the PR in content, the longer the green color duration. These results demonstrate that KB was the best and PR the worst among CSG grown in USGA system under a domestic climate, in regards of turf quality, color, mowing quality, summer turf performance and green color duration. KB and TF are most adequate for high-maintenance and low-maintenance area, respectively. In case of mixtures for high-quality turf, it was desirable to use KB-based mixture with PR of below $20\%$ in seeding rate.

• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.1
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• pp.99-109
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• 1997

The in situ observations and the seawater analyses were conducted in July and August, 1996 for the purpose of describing the characteristics of organic pollution, dissolved oxygen distributions, and the evaluation of water quality in Mokpo harbour. The vertical density distribution of water column was found to be in stable structure with higher water temperature and lower salinity on surface layer at ebb tide in summer. In July, dissolved oxygen was shown to be oversaturated on surface and bottom layers, while in August, which was shown to be oversaturated on surface layer, and to be unsaturated on bottom layer as 68∼93% of saturation percentage. Dissolved oxygen of bottom layer in August was evaluated to be under the regular grades, based on Korean standards of seawater quality. In view of COD, the seawater quality of Mokpo harbour in summer was evaluated to be deteriorated due to organic wastes and graded to be the third class, and TSS of Mokpo harbour in summer was graded to be the second class, based on Korean standards of seawater quality. In particular, COD of surface layer in August was found to be under the regular grades. It is, therefore, necessary to take measures for the control of pollution loads and the proper management of seawater quality in Mokpo harbour. The distribution patterns of DO, COD, VSS and Chlorophyll-a on surface layer along the downstream center line from inner harbour to harbour entrance were similar to one another at ebb tide in August.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.3
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• pp.215-220
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• 2000

This study was conducted to evaluate the dry matter yield and quality of the before and after renovation of summer depression damaged pasture, and carried out at Chungnam National University ffom 1997 to 1999. The yield of DM in first and second year of after renovation, comparing with those of before renovation(6,547kg/ha), significantly increase obtained 12,291kglha and 13,50Ikg/ha, respectively(P<0.05). In the chemical composition, CP content and DM digestibility were markedly increased comparing with those of before renovation(P<0.05), but the contents of NDF, ADF, cellulose and lignin were decreased respectively(P<0.05). In the botanical composition, weeds after renovation was markedly decreased comparing with before renovation, but increased the percentage of herbage in summer depression damaged pasture. The results from this study, It is proved that a renovation method, which was conducted by two times of reseeding and raking, was effective in recovering botanical composition of herbage, and enhancing productivity and upgrading quality in summer depression damaged pasture. (Key words : Renovation, Reseeding, Summer depression)

• Korean Journal of Community Nutrition
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• v.10 no.4
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• pp.501-512
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• 2005

To assess the food habits and the seasonal differences of nutrient intakes and diet qualities of adult working women aged 30 - 49y in Busan, dietary survey was conducted in summer and in winter by a questionnaire and two-day food record. Anthropometric assessment was also investigated in two seasons. $91.8\%$ of those skipped breakfast in the main. $44.3\%$ had irregular meals. The mean daily energy intake was 1725.8 kcal with $63.3\%$ of energy intake being supplied by carbohydrates, $14.7\%$ by protein, $22.3\%$ by fat in summer and 1598.4 kcal with $62.1\%$ of energy intake being supplied by carbohydrates, $15.6\%$ by protein, $22.1\%$ by fat in winter. Over $70\%$ of iron intake came from plant origin in two seasons. The mean intakes of energy, calcium, iron and vitamin A in summer and energy, calcium, iron, vitamin A and vitamin $B_2$ in winter were below Recommended Dietary Allowance (RDA) for Koreans. As well as insufficiency in iron, the bioavailability of iron is considered to have been low because most of iron intake came from plant origin in two seasons. For calcium and iron in summer and calcium, iron, vitamin A and vitamin $B_2$ in winter, proportions of subjects with intake levels less than $75\%$ of RDA were over $40\%$ in summer and over $50\%$ in winter, respectively. The nutrient adequacy ratios (NAR) were below 0.75 for calcium and iron in summer and calcium, iron, vitamin A and vitamin $B_2$ in winter. NARs of iron (p<0.05), vitamin A (p<0.01) and vitamin $B_2$ (p<0.001) in winter were significantly lower than those in summer. The mean adequacy ratios (MAR), an index of overall dietary quality were 0.85 in summer and 0.80 in winter. The MAR in winter was significantly lower than that in summer (p < 0.05). The indexes of nutritional quality (INQ) were below 1 for calcium and iron in summer and calcium, iron, vitamin A and vitamin $B_2$ in winter. The intake (p<0.05) and NAR (p<0.05) of vitamin $B_2$ showed positive significant correlations with height in winter. In conclusion, nutrient intake and diet quality of adult working women were different between the summer and the winter. So nutritional education programs for summer and winter are needed for adult working women.

• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.328-334
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• 2022

BACKGROUND: The low temperature at flowering period break the balance between vegetative and reproductive growth of apple tree. Summer pruning has been used to control vegetative growth. So, this study was conducted to investigate the effect of summer pruning time on shoot growth and fruit quality of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period. METHODS AND RESULTS: The following treatments were applied to tree : a) control (no summer pruning), b) pruned 26 June, c) pruned 30 July, d) pruned 28 August, and e) pruned 26 September. The summer pruning significantly increased light penetration and fruit red color by reducing the total shoot growth compared with control. And the summer pruning control the outbreak of apple valsa canker. But the summer pruning at the end of June increased regrowth of shoot and pruning weight compared with the summer pruning at the end of August. The summer pruning at 30 July had the highest fruit weight, but return bloom was the highest in the summer pruning at 28 August. CONCLUSION(S): These results indicated the optimum summer pruning time of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period were the end of August.

• Korean Journal of Community Nutrition
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• v.5 no.2
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• pp.333-342
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• 2000

The purpose of this study was to evaluate microbiological quality for each stage of the kimbap manufacturing process in summer and winter. Under the various controlled conditions through the simulation, the time-temperature data were collected and the microbiological quality(including total plate count, coliforms, and fecal coliform count) were evaluated. To determine the expected shelf life of Kimbap, a microbiolgical analysis according to the length of the storage time was performed. The microbiological analysis on both sanitary and unsanitary utensils was compared. The microbiological quality of the raw materials of Kimbap in summer was not at an acceptable level, but that of the heat-treated raw materials of Kimbap met the requirement according to the standards set by the Natick Research Center. The number of the microorganisms of the unsanitary utensils and the Kimbap made from unsanitary utensils was more than the acceptable criteria. Sanitary management is necessary to prohibit cross-contamination and to manufacture Kimbap safely. Results from storage times and storage temperature conditions(chilled and room-temperature storage) showed that the expected shelf-life of the Kimbap with the room-temperature storage was as less than 3 hours in summer, while it was as 7-10 hours in winter.

• Korean journal of food and cookery science
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• v.14 no.4
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• pp.367-374
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• 1998

The purpose of this study was to evaluate the microbiological quality of, and to assure the hygienic safety of, the kimbap production in the university foodservice facilities in accordance with the HACCP (Hazard Analysis Critical Control Point) Program. The time-temperature relationship and the microbiological quality (specifically, total plate count and coliform bacteria count) were assessed to find the critical control point (CCP) during each of the production phases. The average of the daily longest duration time of the kimbap at the facilities was 23.4 hours in summer, while 29.6 hours in winter. In the purchasing phase of the raw materials, the microbiological quality of laver, fish paste, carrot and cucumber in summer was not at an acceptable level according to the standard set by the Natick research center, especially the number of TPC and the coliform level of laver was higher than the threshold level. In the refrigerator storage phase, the temperature of the carrot was 7.4$^{\circ}C$. This temperature is far exceeding the standard so that the microbiological counts was increased by the 2 log cycle during the average storage time of 17 hours or more. In the preparation phase, the temperature of the blanching is too low compared to the standard. In the holding phase before serving, its time-temperature relationship was out of the FDA food code standard both in winter and summer. In the sewing phase, the number of microbiological count was higher than the threshold level in summer while that in winter was up to standard. According to the Harrigan and McCance standard, the number of microbiological count of the utensils was higher than the threshold level in summer while that in winter was up to standard.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.393-399
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• 2017

In order to determine the optimal water intake point, the distribution of blue-Green algae and water quality factors in relation to the depth of the Mulgum and Maeri stations located downstream of the Nakdong River were investigated from Jun. 2015 to Sep. 2016. When the current surface water intake system was converted to the deep water intake system, Chl-a concentration and blue-Green algae were reduced by 64.1% and 80.5%, respectively. Microcystin-LR was reduced by 50% to 100%, while geosmin and 2-MIB of the odorant substances were reduced by 42.9% and 11.8%, respectively. The water quality factors such as pH, water temperature, TOC and COD were gradually decreased by 30% in deep water. Therefore, if we used the deep water intake system selectively in the summer season when blue-Green algae masses occur, the concentration of the influx of blue-green algae and its by-products can be expected to decrease, leading to reduced operation costs in tap water production and improved of raw water quality.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.57-65
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• 1999

The in situ observations and the seawater analyses were conducted at all seasons from July 1996 to April 1999 for the purpose of describing the characteristics of seasonal variations of water quality in Mokpo harbour, Korea. Vertical stratification started to be formed in water column in spring, developed in summer and disappeared in fall. In summer, vertical density distribution of water column was found to be in stable structure with lower temperature and higher salinity of bottom water, and the vertical mixing of water between surface and bottom layers was restricted. In winter, however, surface water was found to be similar to bottom water in temperature and salinity, and water column was in unstable structure and in well-mixed condition between surface and bottom waters. The saturation percentage of dissolved oxygen(DO) in bottom water of inner part of Mokpo harbour at all seasons was shown to be decreased to the third grade or under the third grade of Korean standards of seawater quality. In particular, dissolved oxygen was oversaturated in surface water and undersaturated in bottom water in summer, due to stratification and organic pollution. The difference of DO concentration between surface and bottom waters was found to be greater in spring and summer than in fall and winter, due to stratification and photosynthesis of phytoplankton. The concentrations of chemical oxygen demand(COD) over the entire waters of Mokpo harbour were found to fluctuate from below the third grade to the first grade of Korean standards through all seasons and COD concentrations of same seasons were shown to be different year after year. In particular, in view of COD, the annual average seawater quality of Mokpo harbour was evaluated to be in third grade of Korean standards, due to organic pollution. The average COD of surface water was greater than that of bottom water in spring and summer, due to the autochthonous COD caused by production of phytoplankton in surface waters, while the average COD of surface water was similar to that of bottom water in fall and winter, due to the vertical mixing of water between surface and bottom layers.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.458-468
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• 2021

In this study, we investigated the variations of dissolved organic matter (DOM) in an agricultural reservoir during the monsoon period (June to October, 2020) with respect to the organic carbon concentration (DOC), molecular weight distribution, and optical properties. The monsoon period was divided into three phases - beginning storm (BS), during storm (DS), and after storm (AS). Our results showed significant differences in the concentrations and characteristics of DOM during the summer monsoon. The DOC concentrations were decreased after the monsoon, probably due to a dilution effect. In contrast, increasing trends were observed in the specific UV absorbance (SUVA), and relative abundances of humic-like fluorescence and larger-sized compounds. These observations implied that the large-sized and humic-like organic components with terrestrial origins strongly affected the reservoir DOM after the summer monsoon. Meanwhile, biopolymer size fraction, which is associated with algal activity, became more abundant after the monsoon. These results suggest that DOM with autochthonous sources became dominant as a result of the inflow of nutrients into the reservoir after the storm. Spatial changes in DOM within the reservoir were not pronounced as much as the temporal variations. All taken, it can be concluded that the summer monsoon simply led to the decrease of DOM concentrations while the sources and the quality of DOM underwent substantial changes, which may enrich refractory organic matter in the reservoir. This study reveals the importance of in-depth DOM quality monitoring before and after summer monsoon for effective water quality management in agricultural reservoirs.