• Journal of Korean Society on Water Environment
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• v.34 no.5
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• pp.470-486
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• 2018

This study is to investigate the allochthonous load and water quality of a typical river-reservoir, Paldang during spring (March ~ May) of 17 years (2001 ~ 2017). Phosphorus loading from point sources seems to have been reduced by 74 % in the 2010s. As a result, trophic state of the Paldang reservoir, eutrophic during the 2000s, has returned to the lmesotrophic state. Along with decrease in phosphorus concentration, standing crops of algae (Chl.a) decreased, and concentration of biodegradable organic material decreased to the past level. Concentration of total suspended solids has decreased, and it is due to the decrease of phytoplankton standing crops since the mid-2000s. As transparency increased, it is estimated that euphotic area increased by 22 % and euphotic capacity expanded by 27 %. In the river/transition zone of Paldang, concentration of organic matter increases slightly due to algal growth, but concentration of all water quality items decreases in the lacustrine zone. Although algal growth rate revealed positive correlation with concentration of phosphorus, it was insignificant. Algal growth appeared to be dependent on renewal of phosphorus by flow, than either flow rate or phosphorus concentration. The empirical model including inflow phytoplankton concentration fit well with observed values, and indicates the Paldang reservoir is greatly influenced by allochthonous loads.

• Asian Journal of Turfgrass Science
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• v.10 no.1
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• pp.31-40
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• 1996

The mechanical expresion provides for the use of Soil property reserves and permanent protec-tion or improvement of soil resources in accordance with measurable standards. If the functions I (initial soil property), E (soil erosion), R (soil renewal), and M. (minimum allowable value) are assumed to be integrable in region A, erosion tolerance over a region is leaded to ${\int}_A{\int}I(m, cl, re, ch, b)dA-{\int}_A{\int}{\{\int}_{to}^{\infty}[E(w, re, c, re, ch, b, t)-R(m, ch, re, b, t)]dt}\dA{\geqq}{\int}_A{\int}M_i(m, cl, re, ch, b)dA$ were variable factors are m=parent material of soil, cl=climate, re=relief or topography, ch=soil characteristics, r=rain or water, w=wind, b=biota, and t=time.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.192-199
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• 2003

Trimethylglycine, commonly named betaine, is the most simple amphoteric molecule. It is completely vegetal (1,2), as it is produced in the sugar industry by industrial chromatography of molasses. While abundantly used in foods and diet supplements, many interesting applications in cosmetics have recently been investigated, like its capability to increase the volume and stability of foams in surfactant solutions. For its special chemical structure (it is the internal salt of a weak acid and a strong alkali) trimethylglycine is a solvent and buffering agent for strong acids and Lewis' acids. It allows to improve the efficiency of $\alpha$- and $\beta$-hydroxy acids in increasing the physiological rate of epidermal cell renewal, while keeping a low skin-irritation level. In oral care cosmetics, it acts as a mucous membrane protectant (3). For its special water co-ordination capability, its solubilising power, polymer swelling capability, after-feel improvement in hair products, skin moisturization and elasticity enhancing properties, trimethylglycine provides unusual characteristics to many products intended for skin maintenance (4).(omitted)

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.21-28
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• 2017

This study was performed to propose the sewer defect scoring, and grading protocols for sewer condition assessment. For this, sewer defect scoring methods were comparatively analyzed and reviewed for four international condition assessment protocols, which are established based on WRc manual. As a result, we proposed a new protocol for sewer condition assessment, in which characteristics of sewer pipes are considered by segment. In reference to the PIM-3, the extent of ground subsidence was adopted to be of importance, and renewal scores increased in accordance with weighting of defects causing structural backfill materials. Also, defect grades of 'Hole' were extended to 5 levels of the grading, and 'Surface Damage' was excluded in defect assessment. The addition of 'Buckling' resulted in reduction of weights in 'Surface Damage' and 'Lining Defects'.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.5
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• pp.452-458
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• 2005

In Korea, pumping pipe using gravity way by water is most popular method in drainage system. But, it is difficult to repair a drainpipe in this method because the drain pipe diameter is increased as using this method. In this research, we propose a new drainage system. The system aim for an adaptedness with buildings, freedom of plan, construction and renewal in water pipe equipments, etc. The new system is not need of incline of piping, and it uses drainage power that is changed potential energy by high velocity flow as making Siphonage at vertical pipe. Therefore, the diameter of piping can decreased than existing piping system established in the ceiling. Also because connecting position will be located at the lower part, it is changed the potential energy of drainage to the high velocity flow. In addition, drainage will be smooth because the fixture drain is linked by each drain pipes.

• Journal of Korean Society of Rural Planning
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• v.30 no.2
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• pp.69-77
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• 2024

As impervious area increases due to urbanization, rainfall on the impervious area does not infiltrate into the ground, and stormwater drains quickly. Low impact development (LID) practices have been suggested as alternatives to infiltrate and store water in soil layers. The practices in South Korea is applied to urban development projects, urban renewal projects, urban regeneration projects, etc., it is required to perform literature research, watershed survey, soil quality, etc. for the LID practices implementation. Prior to the LID implementation at fields, there is a need to simulate its' effect on watershed hydrology, and Storm Water Management Model (SWMM) provides an opportunity to simulate LID practices. The LIDs applied in South Korea are infiltration-based practices, vegetation-based practices, rainwater-harvesting practices, etc. Vegetation-based practices includes bio-retention cell and rain garden, bio-retention cells are mostly employed in the model, adjusting the model parameters to simulate various practices. The bio-retention cell requires inputs regarding surface layer, soil layer, and drain layer, but the inputs for the drain layer are applied without sufficient examination, while the model parameters or inputs are somewhat influential to the practice effects. Thus, the approach to simulate vegetation-based LID practices in SWMM uses was explored and suggested for better LID simulation in South Korea.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.29-35
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• 2011

Individual ion concentrations and ionic contributions to EC reading in the circulated nutrient solution are the important factors to be considered for stable EC-based closed-loop soilless culture. This study was conducted to determine appropriate ion-analysis intervals of the circulated nutrient solutions based on ion concentration, ion balance, and ion electrical conductivity under different renewal intervals in EC-based nutrient control systems for sweet peppers (Capsicum annum L. 'Fiesta') in early growth stage. Average node numbers of the plants were 13 and 18 when the experiment started and finished, respectively, and three plants were grown in each rockwool slab. Four different renewal intervals of circulated nutrient solutions such as 1, 2, 3, and 4 weeks were used as treatment. Nutrient solutions were supplied to the plants based on integrated radiation. Drainage was collected into drain tanks after irrigation ended in the day and then mixed with fresh water until the EC reaches 2.69 $dS{\cdot}m^{-1}$. The replenished nutrient solution was supplied to the plants in the next day. Ion concentrations of the individual ions periodically analyzed in the circulated nutrient solutions showed no significant differences among the treatments during the experimental period. Ion concentrations of $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$, $NO_3{^-}$, ${SO_4}^{2-}$, ${PO_4}^{3-}$, and $Cl^-$ varied within 5-8, 11-14, 2.0-2.7, 0.5-0.6, 14-19, 4-5, 1-4, and 0.3-0.5 $meq{\cdot}L^{-1}$, respectively. Ion balance showed a consistent tendency over all the treatments and especially $K^+$ : $Ca^{2+}$ and ${SO_4}^{2-}$ : ${PO_4}^{3-}$ played great roles in the cation and anion balances in the nutrient solutions, respectively. Activity coefficients of ions such as $K^+$, $NO_3{^-}$, and $H_2PO_4{^-}$ varied within 0.8-0.9 and those of $Ca^{2+}$, $Mg^{2+}$, ${SO_4}^{2-}$ varied within 0.5-0.6, showing little changes with time. Ionic contributions of $K^+$ and $NO_3{^-}$ to EC reading were the greatest followed by $Ca^{2+}$, ${SO_4}^{2-}$, and $Mg^{2+}$ in the order. From the results, we thought that allowable ranges in ion concentration, ion balance, and subsequent individual ionic contributions to EC reading would be obtained within 4-week renewal interval of nutrient solution in EC-based closed-loop soilless culture for sweet pepper plants.

• Journal of the Korean Society of Fashion and Beauty
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• v.4 no.1 s.7
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• pp.51-59
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• 2006

Today, SPA fills many of the same needs as they did thousands of years ago, including relaxation, wellness and stress relief by incorporating many of the same methods embraced by the ancients such as a multitude of hydrotherapy treatments, thalassotherapy and massage therapy, one of the most widely used SPA treatments. The definition is as follows: SPA is entities devoted to enhancing overall well-being through a variety of professional services that encourage the renewal of mind, body and spirit. It was from here that the concept of modernday SPA evolved, incorporating full health and beauty services along with sport, aquatic and rest facilities. Todays SPA, a absolute concept, is being specialized and spread as fast as undefinable just in a word. Thalassotherapy, a kind of SPA therapy, contains minerals and trace elements. Born more than 4,000 years ago in ancient Egypt, thalassotherapy comes from the Greek words for thalasso(sea water) and therapeia(to heal). Thalassa was the Greek personification of the Mediterranean Sea that surrounded them and gave them so much of their sustenance. It helps to nourish, hydrate and refine skin texture and also eliminate metabolic waste and toxins in the body. Thalassotherapy is recommended for post-natal and postsurgery recovery period, chronic fatigue, circulatory problems, cellulite control and dermatological problems. It's also possible to enjoy the thalassotherapy SPA as a day guest. Be sure to try the jansu massage, given in the heated sea water pool. As a trained therapist gently whisks clients through the womb-warm water, clients can practically feel the toxins leave their body. Many women from all over the world have been kept up beautiful skin with applying thalassotherapy to their faces and bodies since long times and these days in France, they are getting great curative clinical effects from renovative and scientific technological combination. Thus thalassotherapy will be absolutely ultimate form of natural healing which can keep and recover human's health and beauty.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.901-905
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• 2010

Emissions of leachate, odor, and landfill gas(LFG) from an open-dumping landfill site do harm to public health by contaminating neighboring soil, underground water, and rivers. Particularly, methane($CH_4$) and carbon dioxide($CO_2$), the main components of LFG, are especially noted as the causing material of the global warming that become seriously recognized worldwide issue. As one of alternatives in managing LFG, incineration of inflammable wastes that are generated during excavation process at an open-dumping landfill has been evaluated. Standard on stabilization for evaluation, neither $CH_4$ density nor $CO_2$ density could not Because meet 'less than 5%' criterion and so it is right to install a gas collection system during landfill renewal to prevent diffusion of odor and collect it. Because it shows considerable heating value, incineration of inflammable wastes might be the reasonable solution from the result of our study.

• Nuclear Engineering and Technology
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• v.45 no.7
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• pp.929-940
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• 2013

Environmental fatigue of the metallic components in light water reactors has been the subject of extensive research and regulatory interest in Korea and abroad. Especially, it was one of the key domestic issues for the license renewal of operating reactors and licensing of advanced reactors during the early 2000s. To deal with the environmental fatigue issue domestically, a systematic test program has been initiated and is still underway. The materials tested were SA508 Gr.1a low alloy steels, 316LN stainless steels, cast stainless steels, and an Alloy 690 and 52M weld. Through tests and subsequent analysis, the mechanisms of reduced low cycle fatigue life have been investigated for those alloys. In addition, the effects of temperature, dissolved oxygen level, and dissolved hydrogen level on low cycle fatigue behaviors have been investigated. In this paper, the test results and key analysis results are briefly summarized. Finally, an on-going test program for hot-bending of 347 stainless steel is introduced.