• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.130-134
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• 2013

Purpose: Anthracyclines have been utilized in the treatment of children with acute lymphoblastic leukemia (ALL). Recent studies have shown that anthracyclines may induce toxicity in the vascular endothelium. This study was performed using brachial artery reactivity (BAR) to evaluate vascular endothelial function in ALL patients who were treated with anthracycline chemotherapy. Methods: We included 21 children with ALL who received anthracycline chemotherapy and 20 healthy children. The cumulative dose of anthracyclines in the ALL patients was $142.5{\pm}18.2/m^2$. The last anthracycline dose was administered to the patients 2 to 85 months prior to their examination using BAR. The diameter of the brachial artery was measured in both groups using echocardiography, and BAR was calculated as the percentage change in the arterial diameter after release of the cuff relative to the baseline vessel diameter. Results: In the anthracycline-treated group, BAR was observed to be $3.4%{\pm}3.9%$, which was significantly lower than that observed in the control group ($12.1%{\pm}8.0%$, P<0.05). The time elapsed after the last anthracycline treatment and the age at the time of treatment did not affect the change in BAR (P =0.06 and P =0.13, respectively). Conclusion: These results provided evidence that treatment of ALL patients with anthracycline results in endothelial dysfunction. A larger cohort study and a longer follow-up period will be required to clarify the relationship between endothelial dysfunction resulting from anthracycline treatment for childhood ALL and occurrence of cardiovascular diseases later in life.

• Journal of the Korea Concrete Institute
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• v.15 no.4
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• pp.574-584
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• 2003

The most common deterioration cause of concrete structures in urban environment is carbonation. Recently, the $CO_2$ concentration and temperature at atmosphere is sharply increased with time due to global warming phenomena. In this study, the climate scenario IS92a, which was suggested by the IPCC, is used to consider temperature and atmospheric $CO_2$ concentration change in the model of service life prediction. The modified mathematical solution, which was based on the Fick's 1st law of diffusion, was used to reflect concrete materials properties such as the degree of hydration of concrete with elapsed time, and important parameters, which associated with deterioration rate. The techniques of service life prediction are developed introducing the method of reliability and stochastic concept to consider microclimatic condition in Seoul, South Korea. From the result of service life prediction, concrete containing high W/C ratio is shown fast carbonation rate due to $CO_2$ concentration increase. It is concluded that the deterioration of concrete structures due to carbonation is insignificant problem on the conditions that below W/C 55%, well curing concrete.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.105-118
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• 2015

This study was carried out to investigate the effects of profile disturbance with different artificial accumulation history on physico-chemical properties of soil under plastic film house. The investigations included soil profile description using soil column cylinder auger F10cm x h110cm, in situ and laboratory measurements of soil properties at five sites each at the cucumber (Site Ic ~ Vc) and grape (Site Ig ~ Vg) plastic film houses with artificial soil accumulation. The sites except sites Ic, IVc, IVg and Vg, belong to ex-paddy area. The types of accumulates around root zone included sandy loam soil for 3 sites, loam soil for 1 site, saprolite for 2 sites, and multi-layer with different accumulates for 3 sites. Especially, Site IIg has mixed plow zone (Ap horizon) with original soil and saprolite, whereas disturbed soil layers of the other sites are composed of only external accumulates. The soil depth disturbed by artificial accumulation ranged from 20 cm, for Site IIg, to whole measured depth of 110 cm, for Site IVc, Vc, and Site IVg. Elapsed time from artificially accumulation to investigation time ranged from 3 months, Site IIc, to more than 20 years, Site Vg, paddy-soil covering over well-drained upland soil during land leveling in 1980s. Disturbed top layer in all sites except Site Vg had no structure, indicating low structural stability. In situ infiltration rate had no correlation with texture or organic matter content, but highest value with highest variability in Site IIIc, the shortest elapsed time since sandy loam soil accumulation. Relatively low infiltration rate was observed in sites accumulated by saprolite with coarse texture, presumably because its low structural stability in the way of weathering process could result in relatively high compaction in agro-machine work or irrigation. In all cucumber sites, there were water-transport limited zone with very low permeable or impermeability within 50 cm under soil surface, but Site IIg, IIIg, and Vg, with relatively weak disturbance or structured soil, were the reverse. We observed the big change in texture and re-increase of organic matter content, available phosphate, and exchangeable cations between disturbed layer and original soil layer. This study, therefore, suggest that the accumulation of coarse material such as saprolite for cultivating cash crop under plastic film house might not improve soil drainage and structural stability, inversely showing weaker disturbance of original soil profile with higher drainage.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.41-52
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• 2015

The number of military facilities has been rapidly increased due to growing requirement of modernization and military welfare. However, adequate maintenance has not implemented to these facilities. As a result, they are deteriorated quickly and require performance enhancement treatments. There are two ways of performance enhancement, reconstruction and remodeling. Despite the research result that remodeling within the standard remodeling range is more economical, remodeling of military facilities is not considered equivalent to reconstruction as an option of performance improvement. Therefore, derived from the relationship between performance change during life cycle of building and range of remodeling needs, this study tries to propose Remodeling Process Model(RPM) which uses a method to choose remodeling in a Specific Point of Time(SPT) when remodeling is considered more economical than reconstruction. In addition, this study suggests practical service life and functionality evaluation standard together which require to realize the RPM. This RPM make it possible to avoid the cases that facilities which do not have any problem on structural reliability but have low level of functionality miss appropriate remodeling timing and inevitably choose reconstruction as a performance improvement option. It also present the possibility of simple reconstruction / remodeling decision-making for facility managers who administrate building having various type, compilation and elapsed time. Consequently, this process model focusing on remodeling more may contribute to reduce resource waste caused by reconstruction.

• Journal of Environmental Science International
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• v.16 no.3
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• pp.287-297
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• 2007

Increasing carbon dioxide emissions from fossil fuel use and land-use change has been perturbing the balanced global carbon cycle and changing the carbon distribution among the atmosphere, the terrestrial biosphere, the soil, and the ocean. SGCM(Simple Global Carbon Model) was used to simulate global carbon cycle for the IPCC emissions scenarios, which was six future carbon dioxide emissions from fossil fuel use and land-use change set by IPCC(Intergovernmental Panel on Climate Change). Atmospheric $CO_2$ concentrations for four scenarios were simulated to continuously increase to $600{\sim}1050ppm$ by the year 2100, while those for the other two scenarios to stabilize at $400{\sim}600ppm$. The characteristics of these two $CO_2$-stabilized scenarios are to suppress emissions below $12{\sim}13$ Gt C/yr by tile year 2050 and then to decrease emissions up to 5 Gt C/yr by the year 2100, which is lower than the current emissions of $6.3{\pm}0.4$ Gt C/yr. The amount of carbon in the atmosphere was simulated to continuously increase for four scenarios, while to increase by the year $2050{\sim}2070$ and then decrease by the year 2100 for the other two scenarios which were $CO_2$-stabilized scenarios. Even though the six emission scenarios showed different simulation results, overall patterns were such similar that the amount of carbon was in the terrestrial biosphere to decrease first several decades and then increase, while in the soil and the ocean to continuously increase. The ratio of carbon partitioning to tile atmosphere for the accumulated total emissions was higher for tile emission scenario having higher atmospheric $CO_2$, however that was decreasing as time elapsed. The terrestrial biosphere and the soil showed reverse pattern to the atmosphere.

• The Journal of Engineering Geology
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• v.27 no.1
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• pp.59-66
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• 2017

The characteristic of recent rainfall pattern in Korea is concentrated in summer season and it is very different compare with former characteristic. In 2011, there was heavy rainfall in Chuncheon city of northern part of Korea. Because of rainfall in short time, many landslides were occurred in narrow area and many people were killed by these landslides at that time. The purpose of this study is to calculate run-out distance of debris flow and analyze the movement properties of debris flow according to the elapsed time using numerical analysis method at that time. The debris 2D program, which is developed by prof. Liu in National Taiwan University, was used in this study. Run-out distance of debris flow was calculated under different yield strength conditions which were controlled by rainfall amount. The results reveal that absolute maximum velocity of the debris flow is about 8.1 m/s and maximum depth of debris flow is about 7 m when debris flow was occurred. The run-out distance after 500 sec is about 300 m from end of the valley. It is very well similar with actual debris flow run-out distance. From these results, we can presume the maximum velocity and depth of debris flow at that time.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.228-230
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• 2007

In this study, we investigated the change in lead content of canned coffee drinks while kept for 16 weeks in an incubator adjusted to $65^{\circ}C$. Our research aim was to ensure the safety of canned coffee purchased from vending machine and stores. The lead analysis were conducted by graphite furnace atomic absorption spectrometry after wet digestion using concentrated nitric acid. The results showed that the lead contents of all examined samples were very low at a level of not detected to 0.033 mg/L, and below 2 mg/kg, the Korean regulatory limit for the commodity. Also, no increase in lead content was observed over the elapsed time. Therefore, it appears that lead is not a hazard and need not be a concern in drinking canned coffee.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.12
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• pp.1-6
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• 2004

In this study, heat and discharge treatments are arbitrary simulated for finding out the initiations and processes of surface degradation on the surface of polymer for using as a PCB substrate. Thermal-treatment changed the surface to the hydrophobic one with the increase of contact angle and surface potential decay, respectively. The XPS spectrum showed that the increased hydrophobicity in thermal treatment was originated from the continuous decrease of side-chains caused by secessions of oxygen groups and the increase of unsaturated double bond in carbon chains. Also, thermal-treatment caused the discoloration on the point of treated surface. These phenomena were attributed to the generation of ether group. In the chemical change by discharge treatment, a lot of side-chains occurred on the treated surface, and so the hydrophilicity increased as time elapsed.

• Journal of Energy Engineering
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• v.7 no.1
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• pp.89-95
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• 1998

Maintenance scheduling of generators plays an important role in evaluating supply reliability of power systems. Since generators must be maintained and inspected, the generation planner must schedule planned outages during the year. Several factors entering into this scheduling analysis include: seasonal load-demand profile, amount of maintenance, size of the units, elapsed time from last maintenance, and availability of maintenance crew. This paper proposes a new maintenance scheduling algorithm for the alternatives of long-term generation expansion planning by using LOLP levelization method which is known as an effective method for the generator's maintenance scheduling. To get the best supply reliability of power systems, we change the maintenance period to levelize the reliability over all period. The proposed algorithm is applied to a real size power system and the better reliability results are obtained.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.61-65
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• 2016

In this study, we considered the ignition possibility for the shredded thermoplastic elastomer at the fire ground loaded the waste TPE. The average moisture content of the TPE sample was almost 0.33 wt.% at $110^{\circ}C$ and the range of ignition point was $461.9{\sim}491.9^{\circ}C$ approximately. In addition, we analyzed the change of weight and calorie the TPE sample according to temperature variations using the TG-DTA analyzer. As a result, the weight loss occurred twice in $250{\sim}420^{\circ}C$ and $420{\sim}473^{\circ}C$, and we found the second weight loss temperature range was the ignition point of TPE. Also, we conducted the spontaneous ignition tests of TPE for the wet and dry samples and we confirmed that the possibility of spontaneous ignition of TPE was very low. The elapsed time and humidity had little influence on the spontaneous ignition of TPE in this experimental conditions. In conclusion, the spontaneous of the shredded waste TPE in this study.