• Journal of Korean Society of Steel Construction
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• v.25 no.1
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• pp.61-70
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• 2013

A turn-buckle is capable of adjusting the tensile force by left-hand threads and right-hand threads between tension members. There are different types of turn-buckles according to tension member and connection form but the practical and existing turn-buckles are incapable of measuring the tensile force. A turn-buckle for adjusting and measuring tensile force has therefore been developed. This study shows the ultimate strength and reliability for measurement of the new turn-buckles through finite element analysis of the developed ones. From analytic results of the new turn-buckles which have the measurement limit loads of 100kN, 200kN and 300kN, the ultimate strength is approximately five times stronger than the measurement limit capacity. Additionally, a review of the new turn-buckle, which has the measurement limit load of over 300kN, shows that there is a tendency for the size of turn-buckle to become larger. So the connection devices were designed and the loading test was conducted from the concept that the parallel connection of turn-buckle with 300kN capacity can measure the tensile force of 600kN. The results of parallel loading test show the sufficient possibility. Furthermore, the mock-up test was constructed to investigate the release of initial load and corrosion when the new turn-buckle is installed at the outdoor and exposed to rain and atmosphere.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.139-145
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• 2011

The practice of asphalt pavement recycling has grown rapidly over the decade, one of which is the cold in-place recycling with the foamed asphalt (CIR-foam) or the emulsified asphalt (CIR-emulsion). Particularly, in Iowa, the CIR has been widely used in rehabilitating the rural highways because it significantly increases the service life of the existing pavement. The CIR layer is typically overlaid by the hot mix asphalt (HMA) to protect it from water ingress and traffic load and obtain the required pavement structure and texture. Most public agencies have different curing requirements based on the number of curing days or the maximum moisture contents for the CIR before placing the overlay. The main objective of this study is to develop a moisture loss index that the public agency can use to monitor the moisture content of CIR layers in preparation for a timely placement of the wearing surface. First, the moisture contents were measured in the field using a portable time domain reflectometry (TDR) device. Second, the weather information in terms of rain fall, air temperature, humidity and wind speed was collected from the same location. Finally, a moisture loss index was developed as a function of initial moisture content, air temperature, humidity and wind speed. The developed moisture loss index based on the field measurements would help the public agency to determine an optimum timing of an overlay placement without continually measuring moisture conditions in the field.

• Journal of the Korea Concrete Institute
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• v.13 no.5
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• pp.491-498
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• 2001

The failure phenomenon of overlaid concrete structures, such as surface crack and peel-off failure in the contact zone, was investigated due to temperature shock(rainfall). To investigate this failure phenomenon, the surface tensile stress, and the shear stress, the vertical tensile stress in the contact zone were analysed using the non-linear stress-strain relationship of material such as strain-hardening- and strain-softening diagrams. Rainfall intensity, overlay thickness and overlay material were the main variables in the analyses. It is assumed that the initial temperature of overlaid concrete structures was heated up to 55$\^{C}$ by the solar heat. With a rain temperature 10$\^{C}$ and the rainfall intensity of nR=1/a, tR=10min, 60min, the stress states of overlaid concrete structures were calculated. The result shows that only fictitious cracks occurred in the overlay surface and no shear bond failure occurred in the contact zone. The vortical tensile stress increasing with overlay thickness was proved to be the cause of peel-off failure in the contact zone. The formulae for relationship between the vertical tensile stress and overlay thickness, material properties were derived. Using this formulae, it is possible to select proper material and overlay thickness to prevent failure in the contact zone due to temperature shock caused by rainfall.

• Korean Journal of Remote Sensing
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• v.36 no.3
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• pp.475-486
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• 2020

Climate change scenarios are the basis of research to cope with climate change, and consist of large-scale spatio-temporal data. From the data point of view, one scenario has a large capacity of about 83 gigabytes or more, and the data format is semi-structured, making it difficult to utilize the data through means such as search, extraction, archiving and analysis. In this study, a tool for analyzing extreme climate events based on spatial information is developed to improve the usability of large-scale, multi-period climate change scenarios. In addition, a pilot analysis is conducted on the time and space in which the heavy rain thresholds that occurred in the past can occur in the future, by applying the developed tool to the RCP8.5 climate change scenario. As a result, the days with a cumulative rainfall of more than 587.6 mm over three days would account for about 76 days in the 2080s, and localized heavy rains would occur. The developed analysis tool was designed to facilitate the entire process from the initial setting through to deriving analysis results on a single platform, and enabled the results of the analysis to be implemented in various formats without using specific commercial software: web document format (HTML), image (PNG), climate change scenario (ESR), statistics (XLS). Therefore, the utilization of this analysis tool is considered to be useful for determining future prospects for climate change or vulnerability assessment, etc., and it is expected to be used to develop an analysis tool for climate change scenarios based on climate change reports to be presented in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.229-240
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• 1987

Carbonation of concrete is one type of a chemical process. The reaction mechanism is very complex for the case when low-calcium fly ash and blast furnace slag is added. When fly ash and blast furnace slag is used as an admixture in concrete, they improve compressive strength in the long term, permeability and chemical resistance of concrete by a pozzolanic reaction and latent hydraulic property. On the other hand, the pozzolanic reaction of fly ash and latent hydraulic property of the blast furance slag leads to a reduction of the alkalinity of the concrete. It has been pointed out that this will accelerate the carbonation of the concrete and the corrosion of reinforcement steel embedded in the concrete. In order to clarify the effect of fly ash and blast furance slag on the carbonation of concrete, an accelerated carbonation testing of concrete was carried out by varying the conditions of concrete and the initial curing period in water. The test results of accelerated carbonation were compared to the carbonation test results of concrete stored for 15 years in open air, but protected from rain. As a result, the equation for the rate of carbonation based on compressive strength of concrete was proposed.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.360-366
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• 2008

The spatial and temporal variations of the high turbid water by a single event of heavy rain (total 299.1 mm and daily maximum 99.4 mm) were studied in Andong Reservoir, which has hypolimnetic discharges. Turbid water entered into the reservoir, was isolated from the bottom at the midreservoir and then passed through the metalimnion as an interflow current in the lacustrine zone. Maximum turbidity was 290 NTU at 16 m depth of the midreservoir, but the initial turbidity showed about 10 NTU in the reservoir before the rainfall. Turbid water in the reservoir affected to increase the withdrawal turbidity from the 3rd day after the rainfall, the maximum turbidity was 129 NTU at 5th day after the rainfall. Turbid water that flew towards the downreservoir distributed within 5 m above the outlet gate of the intake tower, showing the maximum turbidity, and that was decreased in its thickness and concentration by discharging through the intake tower. It has taken 38 days until the turbidity in the withdrawal reduced to 30 NTU, and 87 days to reduce the turbidity to the way when it was before the rainfall, with the correlation coefficient of 0.96 and 0.97, respectively. Turbid water was withdrawn from the reservoir by entraining into the intake tower as a form of the interflow, and not be settled down to the bottom of the reservoir. Therefore, we assessed that the depth of the withdrawal was appropriately positioned in Andong Reservoir, so as to withdraw the turbid water effectively from the reservoir.

• Journal of Environmental Impact Assessment
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• v.20 no.5
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• pp.651-661
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• 2011

The purpose of this study is to estimate the characteristics and pollutant loadings of non-point pollutants that flowed in the streams on precipitation for pollutant loading reduction of Hwa-sung lake inflow streams. Although it has been made an effort to improve the water quality of Hwa-sung basin through the strategies for the preservation of water quality, it is shown that the water quality is not greatly improved. Because it has been industrialized and urbanized near Hwa-sung basin so that it is difficult to reduce the water pollution due to the increase in pollutant loadings of point and non-point sources. In this study, it is investigated the outflow characteristics of non-point pollutants that discharged with storm runoff and estimated the effect of runoff on Hwa-sung basin. The final goal of this study is to utilize the basic information for proper management and strategies of non-point sources on Hwa-sung basin. At the result of inflow streams, Ja-an stream that has the greatest pollutant loadings on precipitation is strongly influenced on the water quantity of Hwa-sung basin. On the other hand, it is shown that Nam-yang stream is strongly influenced on the SS concentration of Hwasung basin among them. Also, all streams; Nam-yang, Ja-ahn, Ah-eun stream; has the degree of slope more than or near 1 in the correlation results so that they have strong pollutant loading impact and the concentration of SS is the highest among other pollutants. So, specific studies on initial rain phenomena are more necessary to manage the pollutants economically. Also, the proper control of SS concentration is required to manage the effluent pollutants effectively on precipitation. So, it is necessary to consider the strategies for non-point pollutants as well as point pollutants when the new management is imposed to reduce the pollutant load for improvement of Hwa-sung basin.

• The Journal of Internal Korean Medicine
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• v.15 no.2
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• pp.318-346
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• 1994

A Bibliographical study was done about lumbago in oriental internal Medicine. The results are as follows. 1. Shenxu,sexual active, senile, Feng, Han, Shi, shiji, Tanyin and Qi lumbago are applicable to internal medical lumbago in oriental medicine, and Shenxu is essential pathogenesis. 2. Shenxu lumbago is characterized by continous pain, improved after chiropsia, deep pulse in Chi pulse, and used QingeWan, LiuweiDihuangWan and AnshenWan in herb-medicine. and Cortex Eucommiae, Radix Rehmanniae Praeparata and Fructus Psoraleae in drugs for the purpose of ZishenYijing, and related to lumbago caused by chronic prostatitis, calculus or tumor in kidney and diabetes mellitus. 3. Sexual active lumbago is dim-aching and weak pain in or after sexual life at low back and knee joint, and classified to Shenyang Buzu, ShenjingKuisun. GanshenYinxu and XinshenBujiao ; Liuwei Dihuang Wan, ZuoguiWan In herb-medicine. Cornu Cervi Pantotrichum, Fructus Lycii and Fructus Corni in drug were used for treatment. 4. Senile Lumbago is a kind of consumptive disease due to exhaused essential energy and caused by lack of Shenjing, Yangqi ; and described as repeated mild dim pain and ErzhiWan, QingeWan and MoyaoGao were used frequently, supposed to connected with osteoporosis, osteomalacia and osteoarthropathy deformons caused by aging. 5. Feng lumbago is attacked by Liuyin, and characterized by chilling and fever. stabbing pain from thoracic and lumbar vertebrae to pedes, and used WujiXan, XiaoxumingTang for treatment. Han lumbago is caused by cold's attacking Shenjing, distinguished for chilling,icing sense improved by heat on low back, and used WujiXan, JiangfuTang. Shi lumbago is caused by damp's inflowing Shenjing, described as stone-like lumbago which was subsided low back pain growing worse by gloomy rain, and used ShenshiTang. ShenzhuTang for the purpose of ZaoshiXingqi. And it is supposed that lumbago occured in the initial of urinary track infection was belong to those of Feng,Han and Sill's. 6. Sillji lumbago is caused by pathogen being in the spleen and the stomach, and used ChenxiangJiangqiTang, PingweiSan for treatment. And it is supposed that it belong to lumbago caused by gastrointerstinal disease such as peptic ulcer. gastroduodenal tumor and colonic inflammatory disease. 7. Tanyin lumbago is caused by Tanyin's flowing meridian, characterized by thoracolumbar verterber's heaviness, covered sense with something on low back and painless massage. Kuaiqi-drug are added to ErchenTang, DaotanTang for treatment, and it supposed that Tanyin lumbago's belong to that accompanied with metabolic disease such as obesity and gout. 8. Qi lumbago is caused by excessive stress such as melancholy and fury, described as multiple stabbing pain, an unexpected on and improvement, ranging back pain until flank and abdomine. Tiaoqi-drugs were added to RenshenShunqiSan, WuyaoShunqiSan for treatment, and it supposed to connecting with emotional lumbago such as hysteria, feigned illness and anxiety psychosis.

• Journal of Radiation Protection and Research
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• v.25 no.1
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• pp.21-30
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• 2000

For analyzing the direct contamination pathway of radionudides in rice plants, a Solution containing $^{54}Mn,\;^{57}Co,\;^{85}Sr,\;^{103}Ru$ and $^{134}Cs$ was applied to the aboveground Parts of the between RI application and harvest. Its highest observed value was 0.94. The fractions of the initial plant deposition that remained in rice plants at harvest were in the range of $19{\sim}47%,\;17{\sim}43%,\;19{\sim}42%,\;23{\sim}61%$ and $11{\sim}69%$ for $^{54}Mn,\;^{57}Co,\;^{85}Sr,\;^{103}Ru$ and $^{134}Cs$, respectively, when no decay was assumed. The translocation factors of those radionuclides in hulled seeds were in the range of $6.9{\times}10^{-4}3.8{\times}10^{-2},\;3.6{\times}10^{-3}{\sim}1.6{\times}10^{-1},\;5.8{\times}10^{-4}{\sim}3.2{\sim}10^{-2},\;1.6{\times}10^{-4}{\sim}7.6{\times}10^{-3}$ and $3.2{\times}10^{-2}{\sim}2.0{\times}10^{-1}$, respertively, and were highest when they were applied at the stage of active seed development. It was indicated that the remaining percentage and translocation factor would not be greatly affected by the difference in the rain frequency if it is within a factor of 2. These results can be utilzed for predicting the radionuclide concentrations in rice seeds when an accidental deposition of those radionuclides occurs during the rice-growing season.

• Journal of Korean Society of societal Security
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• v.4 no.2
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• pp.65-72
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• 2011

This study was carried out to investigate the cause of acidification of rainwater and to evaluate the possibility of alternative water resource in Saemangeum. The rainwater were collected in the kwangwhal-myun, Saemangeum from March to September, 2009. The collected 7 samples were analyzed with pH meter, IC (ion chromatography) and ICP (inductively coupled plasma) about the pH and the major ions ($SO{_4}^{2-}$, $NO_3{^-}$, $Cl^-$, $Ca^{2+}$, $K^+$, $NH^{4+}$, $Na^+$ and $Mg^{2+}$) of rainwater. The order of the major anion concentration and the acidification contribution in the rainwater was $SO{_4}^{2-}$>$NO_3{^-}$>$Cl^-$, and that of the major cation was $Ca^{2+}$>$K^+$>$NH_4{^+}$>$Na^+$>$Mg^{2+}$. In the initial rainwater, the major ions concentration were higher than the middle period. pH of the rainwater was the lowest at May, but similar to the results of the others. And pH of the rainwater were significant correlation with $SO{_4}^{2-}$ and $Cl^-$ in Saemangeum. From this results, the rainwater was slight acidic, and $SO{_4}^{2-}$ was the main factor contributed to the rainwater acidification in Saemangeum.