• Journal of Environmental Impact Assessment
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• v.9 no.2
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• pp.143-153
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• 2000

This study was performed to investigate the heavy metal contents and distribution in soil, sediment, and rice from the downstream area of ManKyeong and DongJin River. Of the sites on Mankyeong river area, site M-1(Mokchon bridge) showed the highest average contents of Cd, Cr and Pb in paddy soil. In DongJin river area, site D-3(Munpo) and D-4(Gerjeonri) showed relatively high level of average contents of Cr, Pb and Zn in paddy soil. The average contents of heavy metals in brown rice from ManKyeong river area were 0.10mg/kg for Cd, 0.99mg/kg for Cr, 2.07mg/kg for Pb, 4.44mg/kg for Cu and 32.03mg/kg for Zn while those in brown rice from DongJin river area were 0.14mg/kg for Cd, 0.74mg/kg for Cr, 1.78mg/kg for Pb, 4.57mg/kg for Cu and 33.60mg/kg for Zn. Zn showed the highest transportation-rate from paddy soil to brown rice while Pb showed the lowest. From the results of heavy metal analysis in sediments, the average contents of Cd, Cr, Pb and Cu were generally high in site M-5(Euonri) and D-4(Gerjeonri), the most downstream sites in Mankyeong river and DongJin river, respectively.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.287-294
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• 2008

This study proposes a novel method for in service evaluation of tension force of a prestressed 7-wire strand which is frequently employed for retrofitting bridge superstructure. The smart strand is made by replacing the straight king wire of the strand with an instrumented steel tube in which the FBG sensor is embedded. Since the strain of the smart strand can easily be measured using the sensor, it is possible to monitor tension force of the strand during the service. For the sake of demonstrating effectiveness of the proposed strand, we came up with a 7.0m long prototype with 2 FBG sensors, and it is applied as an external tendon to a 6.4m long and 0.6 high RC T-shaped beam. A loading-unloading test has been carried out, and estimated tension forces using the smart strand are compared with measured forces by load cell. The comparison showed that the proposed smart tendon is useful and accurate for monitering tension force of the prestressed tendon.

• Journal of the Society of Disaster Information
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• v.9 no.3
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• pp.324-331
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• 2013

Epoxy asphalt concrete is used to reduce dead load and to increase durability on long-span steel bridge overlay. The strength development properties of epoxy asphalt concrete are affected by time and temperature because epoxy asphalt is two-phase reactive materials. The strength development of epoxy asphalt concrete should be predicted precisely to decide traffic opening time. Based on this background in mind, the prediction model for traffic opening time for epoxy asphalt pavement was proposed in this research. The developed model using nonlinear curve fitting revealed R2 value of 0.943 while the R2 value of the existing model using chemical kinetics was 0.806. An improved precise prediction result is to be obtained when the prediction model uses accurate temperature data of pavement.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.13 no.2
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• pp.242-248
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• 2006

Purpose: The purpose of this study was to identify the effects of a BeHaS exercise program on pain, health status, body weight in middle-aged women who have osteoarthritis in their knees. Method: The participants in this study were eighteen women whose mean age was 56.22years and who had osteoarthritis in the knees. The BeHaS exercise program consists of approximately one and half hour of exercise, two days per week, for twelve weeks. Data were gathered from September 2005 to December 2005 using a questionnaire and measuring VAS for pain, KWOMAC for health status, body weight for scale. Data were analyzed with the SPSS Win 11.0 using frequency and paired t-test for differences between pre-exercise and post-exercise. Results: The results of this study are as follows: Scores for pain on post test were statistically lower than pre test(t=4.202, p=0.001), health status was statistically improved after exercise program (t=3.479, p=0.002). But body weight did not change(t=-.774, p=0.222). Conclusion: From these results, it is concluded that the BeHaS exercise program can be effective in decreasing pain and increasing health status in middle-aged women with knee osteoarthritis.

• The korean journal of orthodontics
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• v.52 no.6
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• pp.412-419
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• 2022

Objective: This study evaluated the effect of cyclic pre-calcification treatment on the improvement of bioactivity and osseointegration of Ti-6Al-4V mini-screws. Methods: The experimental groups were: an untreated group (UT), an anodized and heat-treated group (AH), and an anodized treatment followed by cyclic pre-calcification treatment group (ASPH). A bioactive material with calcium phosphate was coated on the mini-screws, and its effects on bioactivity and osseointegration were evaluated in in vitro and in vivo tests of following implantation in the rat tibia. Results: As a result of immersing the ASPH group in simulated body fluid for 2 days, protrusions appearing in the initial stage of hydroxyapatite precipitation were observed. On the 3rd day, the protrusions became denser, other protrusions overlapped and grew on it, and the calcium and phosphorus concentrations increased. The removal torque values increased significantly in the following order: UT group (2.08 ± 0.67 N·cm), AH group (4.10 ± 0.72 N·cm), and ASPH group (6.58 ± 0.66 N·cm) with the ASPH group showing the highest value (p < 0.05). In the ASPH group, new bone was observed that was connected to the threads, and it was confirmed that a bony bridge connected to the adjacent bone was formed. Conclusions: In conclusion, it was found that the surface treatment method used in the ASPH group improved the bioactivity and osseointegration of Ti-6Al-4V orthodontic mini-screws.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.4
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• pp.11-17
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• 2022

Ginseng hydroponic cultivation was cultivated as a nutrient solution and the growth was investigated 60 days later. The length(cm) increased from EC1.0 and EC2.0 concentrations to 5.47cm before, followed by EC0.5, 2.5, 1.5, and 0.0. The weight(g) increased from EC1.0 concentration to 2.39g before, followed by EC1.5, 2.5, 0.5, 0.0 and 2.0. The width(mm) increased from EC1.0 concentration to 1.9mm than before, followed by EC2.5, 0.5, 1.5, 2.0, and 0.0. In the ginseng growth experiment according to nutritional components, the average length of NO₃-N mixed experiment increased to 0.33cm, the average weight of 0.04g, and the average width of 0.35mm. In the experiment in which NH₄-N was mixed without NO₃-N, the growth was reduced to 0.37cm in average length, 0.03g in average weight, and 0.22mm in average width. In an experiment in which germanium(Ge) is mixed with a nutrient component, the average length is increased to 0.33cm, the average weight is increased to 0.04g, and the average width is increased to 0.35mm, but in an experiment excluding germanium(Ge), the growth is reduced to 0.11cm, the average weight is 0.04g, and the average width is 0.03mm.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.105-108
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• 1993

A new devised conductivity meter was used in the rapid and convenient determination of salt contents of soysauce and margarine. The equation $(1){\sim}(5)$ was set up between the electric conductivity (x) for 100 times diluted solution of soysauce and the salt contents (y). y=0.083x-1.253 $(at\;15^{\circ}C)$ (1) y=0.077x-2.062 $(at\;20^{\circ}C)$ (2) y=0.071x-2.686 $(at\;25^{\circ}C)$ (3) y=0.066x-3.153 $(at\;30^{\circ}C)$ (4) y=0.062x-3.522 $(at\;35^{\circ}C)$ (5) y=(-0.001139t+0.0999)x+(-0.126t+0.557) $(temperature\;range;\;15{\sim}35^{\circ}C)$ (6) y=salt contents [%], x=conductivity $[{\mu}{\Omega}^{-1}{\cdot}cm^{-1}]$, $t=temp.\;[^{\circ}C]$. The salt contents could be estimated by the equation $(1){\sim}(6)$ and the measured conductivity. The estimated salt contents agreed with that determined by conventional method within 0.27[%] as salt contents. For margarine, the equation (7) was setup between the conductivity (x) and the salt contents (y) y=0.00266x+0.057 $(at\;20^{\circ}C)$ (7) y=salt contents [%], x=conductivity $[{\mu}{\Omega}^{-1}{\cdot}cm^{-1}]$ The salt contents estimated with the equation (7) and the measured condutivity agreed with that determined by conventional method within 0.028[%] as salt contents. The electric conductivity obtained with conductivity meter could be a valuable criteria salt contents test of Korean soysauce and margarine determining in a few second or minute by handy compact portable meter.

• Korean Circulation Journal
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• v.53 no.8
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• pp.535-547
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• 2023

Background and Objectives: Veno-arterial extracorporeal membrane oxygenation (VAECMO) as a bridge to eventual heart transplantation (HT) is increasingly used worldwide. However, the effect of different VA-ECMO types on HT outcomes remains unclear. Methods: This was a retrospective observational study of 111 patients receiving VA-ECMO and awaiting HT. We assessed 3 ECMO configuration groups: peripheral (n=76), central (n=12), and peripheral to central ECMO conversion (n=23). Cox proportional hazards regression and landmark analysis were conducted to analyze the effect of the ECMO configuration on HT and in-hospital mortality rates. We also evaluated adverse events during ECMO support. Results: HT was performed in the peripheral (n=48, 63.2%), central (n=10, 83.3%), and conversion (n=11, 47.8%) ECMO groups (p=0.133) with a median interval of 10.5, 16, and 30 days, respectively (p<0.001). The cumulative incidence of HT was significantly lower in the conversion group (hazard ratio, 0.292, 95% confidence interval, 0.145-0.586, p=0.001). However, there was no difference in in-hospital mortality (log-rank p=0.433). In the landmark analysis, in-hospital mortality did not differ significantly among the 3 groups. Although we did note a trend toward lower HT in the conversion group, the difference was not statistically significant. Surgical site bleeding occurred mainly in the central, while limb ischemia occurred mainly in the peripheral groups. Conclusions: We suggest that if patients are being stably supported with their initial ECMO configuration, whether it is central or peripheral, it should be maintained, and ECMO conversion should only be cautiously performed when necessary.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.23-37
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• 1990

In order to disclose the contamination of the Mushim-Cheon by pollutants in August and September of 1989 and to establish countermeasures, the collected water samples were analyzed to obtain the following results : 1. The water temperature of the period ranged from 25.8 to $30.8^{\circ}C$ acceptable for the growth of microorganisms and algae to allow the self-purification of the stream. 2. The pHs at the sites during the same period ranged from 6.5 to 8.5 which fall within the allowed values for the first grade water supplies except for site 14. 3. At site 18 which is the confluence of the sewer of the excretion disposal facilities and the main stream, the DO was observed to fall down to 0.7 ppm in September. 4. The BOD value reached a maximum of 62.1 ppm at site 18, which far exceeded the limit of 40 ppm, the allowed value for the discharges from the disposal facilities. In addition, the SS values were 200 and 520 ppm in August and September, respectively, which were three to seven times as high as the allowed limit of 70 ppm. 5. The high $NH_3-N$ value of 46.2 ppm at site 18 in September suggested that the water was heavily contaminated with excretions. 6. The BOD load of the sewage from site 12, the Sajik-Dong Sewer, in September was estimated to be about 0.306 ton/day. 7. The contamination of the influents, the family wastewater, and the discharges from the disposal facilities was greater than that of the main stream. 8. In the samples collected from site 12, the Sajik-Dong sewer at an interval of every two hours, a close correlation was observed between the pollutant load and the life cycle of the nearby inhabitants. 9. Compared with the results obtained from the water samples in 1979, it was observed that the water was heavily contaminated at site 12 (the Sajik-Dong Sewer, under the Chung Ju Great Bridge) and site 15 (Under the 2nd Uncheon Bridge) over the last 10 years, with little difference at site 9(Young Un-Dong water supply source).

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.225-231
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• 2017

Objective : Solid bone fusion is an essential process in spinal stabilization surgery. Recently, as several minimally invasive spinal surgeries have developed, a need of artificial bone substitutes such as demineralized bone matrix (DBM), has arisen. We investigated the in vivo bone growth rate of DBM as a bone void filler compared to a local autologous bone grafts. Methods : From April 2014 to August 2015, 20 patients with a one or two-level spinal stenosis were included. A posterior lumbar interbody fusion using two cages and pedicle screw fixation was performed for every patient, and each cage was packed with autologous local bone and DBM. Clinical outcomes were assessed using the Numeric Rating Scale (NRS) of leg pain and back pain and the Korean Oswestry Disability Index (K-ODI). Clinical outcome parameters and range of motion (ROM) of the operated level were collected preoperatively and at 3 months, 6 months, and 1 year postoperatively. Computed tomography was performed 1 year after fusion surgery and bone growth of the autologous bone grafts and DBM were analyzed by ImageJ software. Results : Eighteen patients completed 1 year of follow-up, including 10 men and 8 women, and the mean age was 56.4 (32-71). The operated level ranged from L3/4 to L5/S1. Eleven patients had single level and 7 patients had two-level repairs. The mean back pain NRS improved from 4.61 to 2.78 (p=0.003) and the leg pain NRS improved from 6.89 to 2.39 (p<0.001). The mean K-ODI score also improved from 27.33 to 13.83 (p<0.001). The ROM decreased below 2.0 degrees at the 3-month assessment, and remained less than 2 degrees through the 1 year postoperative assessment. Every local autologous bone graft and DBM packed cage showed bone bridge formation. On the quantitative analysis of bone growth, the autologous bone grafts showed significantly higher bone growth compared to DBM on both coronal and sagittal images (p<0.001 and p=0.028, respectively). Osteoporotic patients showed less bone growth on sagittal images. Conclusion : Though DBM alone can induce favorable bone bridging in lumbar interbody fusion, it is still inferior to autologous bone grafts. Therefore, DBM is recommended as a bone graft extender rather than bone void filler, particularly in patients with osteoporosis.