• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.2
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• pp.51-57
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• 2000

Cylinder machine usually gives more fiber orientation than fourdrinier and has limitation in machine speed because of fiber wash-off caused by centrifugal force when machine speed increases. This study aimed for the improvement of paper formation and productivity by setting an apron in vat inlet and by adjusting mould water head. Improvement of formation and increase of machine speed were achieved, which ultimately improve productivity. Installing an apron successfully decreased fiber wash-off. Fiber orientation and two-sideness of ash distribution became less severe. The proper adjustment of water head inside the cylinder mould proved to be an important factor not only in paper formation but also in decreasing paper two-sideness.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.303-313
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• 2005

Agricultural environmental indicators (AEIs) are useful tool for evaluating environmental performance induced by agri-environmental policy measures. General and specific criteria have been set to assess the linkages between policy measures and environmental states. In addition, a number of specific AEIs such as nutrient balance indicators and farm management indicators have been posit to review environmental performance associated with agri-environmental policy measures. The proposed environmental subjects encompass soil quality, qualities of underground and surface water, water resource preservation, species and genetic diversity, diversity for wildlife habitats, and agricultural landscapes. The developed AEIs may contribute to establishment or adjustment of environmental targets and ex-ante or ex-post evaluation for environmental performance associated with policy measures. In addition, the AEIs may be useful to consider introduction of new agri-environmental measures and enhance policy efficiency by assessing environmental performance, considering specific locality, and harmonizing support measures.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.3
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• pp.71-87
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• 2007

In order to improve and manage rationally for Youngdam creek in Haman-gun, the channel change, water quality and ecological adaptation etc. were evaluated by monitoring during three years. The distinct differences of channel characteristics appeared in the extents of bed excavation and the revetment methods because overall reconstruction was occurred intense disturbance of width expansion and levee construction etc. The scour and deposition were caused according to channel characteristics of ripple and pool, and the adaptation of vegetation was distinguished from each revetment methods clearly. Water quality was maintained first class on the basis of BOD as 0.5~1.5mg/${\ell}$. The vegetation appeared in 380 species close-to-nature river improvement before, but 64 species it after one year, 159 species it after two year and 158 species it after three year. The animal life appeared in 123 species of close-to-nature river improvement before, but 103 species it after one year, 116 species it after two year and 119 species it after three year.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.508-515
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• 2006

This study was conducted from July to December 2004, in order to find measures to improve the water quality and the function of pond ecosystems which are often negatively affected by phytoplankton and suspended particle matters. Most of the time, the management of ponds in Korea does not consider the ecological concepts such as self-purification and nutrient recycling. Instead, conventional methods depend on other factors such as fish farming and the function of fountains and waterfalls. Sustainability of pond ecosystems must be studied with the highest emphasis given to water quality. Water discharges of inflow and outflow as well as balance adjustment for different factors must be thoroughly studied. There is a great need for studies on sustainability because it can be realized through the horizontal or vertical balances of an ecosystem. Our current research offers useful information to the academia and public on maintaining sustainability in terms of structure and function of the pond.

• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.282-290
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• 2013

In this study, the adjustment range of mixture factor with replacement mineral admixture was reviewed to secure the mixture change data of high volume concrete compared to general concrete. When changing the concrete mix to high volume concrete within the universal concrete mixing, the adjustment range of mixture to ensure optimum quality is as follows. Unit-water content is $20{\sim}30kg/m^3$ downward. Fine aggregate ratio dropped by approximately 1% when W/B was reduced by 5%, and it is reduced by approximately 0.12% when there is a 5% increase in the total replacement rate. When the FA replacement rate was increased by 5%, the AE agent was approximately 20% to 30% higher compared with the conventional one. When the FA and BS replacement rate rose by 5%, W/B was reduced by about 1 to 4%.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.630-636
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• 2005

Groundwater contamination by nitrate exceeding water quality criteria (10 mg $NO_3{^-}-N/L$) occurs frequently. Fumarate, acetate, formate, lactate, propionate, ethanol, methane and hydrogen gas were evaluated for their nitrate removal efficiencies and removal rates for in situ bioremediation of nitrate contaminated groundwater. Denitrification rate for each substrate was in the order of: fumarate > hydrogen > formate/lactate > ethanol > propionate > methanol > acetate. Microcosm studies were performed with fumarate and acetate. When fumarate was used as a substrate, nitrate was removed 100 percent with rate of 0.66 mmol/day while conversion rate from nitrate to nitrogen gas or another by-product was 87 percent. 42 mg of fumarate was needed to remove 30 mg $NO_3{^-}-N/L$. When using acetate as carbon source, 31 percent of nitrate was removed during initial adjustment period. Among removed fraction, however, 83 percent of nitrate removed by cell growth. Overall nitrate removal rate was 0.37 mmol/day. Acetate showed longer lag time in consumption compared to that of nitrate, which implying that acetate would be better carbon source compared to fumarate as more amount was utilized for nitrate removal than cell growth.

• Food Science and Preservation
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• v.13 no.2
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• pp.259-268
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• 2006

We investigated food preservation hurdles used for Korean traditional side dishes. As a first step of the research preparation and cooking recipes of the side dishes were surveyed, which are commonly used in Korean households. As next step, compositional and microbial quality attributes were measured onto the samples collected from the market. Antimicrobial ingredient added in the preparation are reasoned to work as important hurdles based on the scientific principles. Heating processes such as blanching, boiling, braising, hard-boiling and frying help to keep the produce decontamination or water activity adjustment. Measured salt contents of most side dishes were in the range of 1-5% with those of salt-preserved vegetables being higher. pH values were 4.7-6.4 with those of salt-preserved vegetables being lower and those of hard boiled fishes being higher. Soluble solids of braised or hard-boiled dishes were usually above $40^{\circ}Brix$, while those of blanched and seasoned vegetables had lower values. Water activity values were 0.93-0.95 for seasoned vegetables and 0.77-0.88 for hard-boiled or semi dried beans and seafoods. Product with processing steps of braising or blanching showed lower bacterial load of 102-104 cfu/g, while seasoned or salt-preserved vegetables and seafoods had aerobic bacterial count above 106 cfu/g. Korean traditional side dishes were found to apply the appropriate combinations of heating preparation process, water activity and pH adjustment and salting, providing the required preservation properties.

• Korean Journal of Ecology and Environment
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• v.56 no.3
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• pp.187-195
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• 2023

Almost all of the water from agricultural dams located to the upper of the Yeongsan river is supplied as irrigation water for farmland and thus is not discharged to the main stream of the river. Also, most of the irrigation water does not return to the river after use, adding to the lack of flow in the main stream. As a result, the water quality and aquatic health of the river have become the poorest among the four major rivers in Korea. Therefore, in this study, several strategies for water quality improvement of the river were developed considering pollution reduction and flow rate increase, and their effect analysis was performed using a water quality model. The results of this study showed that the target water quality of the Yeongsan river could be achieved if flow increase strategies (FISs) are intensively pursued in parallel with pollution reduction. The reason is because the water quality of the river has been steadily improved through pollution reduction but this method is now nearing the limit. In addition, rainfall-related FISs such as dam construction and water distribution adjustment may be less effective or lost if a megadrought continues due to climate change and then rainfall does not occur for a long time. Therefore, in the future, if the application conditions for the FISs are similar, the seawater desalination facility, which is independent of rainfall, should be considered as the priority installation target among the FISs. The reason is that seawater desalination facilities can replace the water supply function of dams, which are difficult to newly build in Korea, and can be useful as a climate change adaptation facility by preventing water-related disasters in the event of a long-term megadrought.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.189-189
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• 1982

This study was carried out to determine the possibility of making fiberboard through the dry forming process, utilizing the tannin-like material of the Asplund pulp from the silk worm oak as a binder. The fiberboard was made through paraformaldehyde treatment, spray of NaOH solution and adjustment of mat moisture content, by hot-pressing at $220^{\circ}C$, and 50-6-50kg/$cm^2$ pressure with 6-min. (0.6-1.8-3.6) three-stage pressing cycle. The results are summarized as follows: 1. The modulus of rupture value of fiberboard treated with NaOH solution was greater than that of untreated. The value was increased in proportion to the paraformaldehyde content from I to 5%, but there was no increasing between 5 and 7% paraformaldehyde content. The value became higher along with the increase of mat moisture content from 15% to 25%. 2. The water adsorption of fiberboard treated with NaOH solution was lower than that of untreated. The value was de"creased in proportion to the paraformaldehyde content from 1 to 5%, but there was no decreasing between 5 and 7% paraformaldehyde content.. 3. A good quality fiberboard (modulus of rupture value of about 250kg/$cm^2$) was made through 5% paraformaidehyde treatment and 3% treatment of 10% NaOH solution, when the mat moisture content was 25%. was 25%.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.1
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• pp.56-63
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• 2003

The dough fermentation and the quality of bread prepared with different kinds of water such as distilled water, tap water and diluted hot spring water(SW) from Gyungsan Sipan hot spring were investigated. Content of total soluble solid in the hot spring water was 8,765 ppm and contents of Na, Ca, Mg and K as major elements was 2,296, 287, 65 and 8 ppm, respectively. Content of Fe, Cu, Co, F, Zn, Al, S, Mo, Se and Si as minor elements was in the range of 0.002~5.2 ppm. The pH(6.95~7.68) of the dough prepared with diluted hot spring water(I, 55 times; II, 4 times; III, 2 times) was higher than that of distilled water. The dough volume after the 1st fermentation was expecially lower in the III, but the volume of the dough prepared with III adjusted pH to 5.5 was higher than that of the control. The hardness and the strength were higher than those of the control, but the scores were love. than those of the control in case of pH adjustment(pH 5.5). The cohesiveness was also lower than that of the control in the bread with diluted hot spring water. Softness and stickiness of the bread(III) were hisher than those of the control. But overall acceptability was the highest in the II.