Sites In Korea Research Articles

A new approach for estimation of the rock mass deformation modulus: a rock engineering systems-based model

The deformation modulus of a rock mass is one of the crucial parameters used in the design of surface and underground rock engineering structures. Due to the problems in determining the deformability of jointed rock masses at the laboratory scale, various in-situ test methods have been developed. Although these methods are currently the best techniques, they are expensive and time-consuming, and present operational problems. To overcome this difficulty, in this paper, based on the basic concepts of a rock engineering systems (RES) approach, a new model for the prediction of the deformation modulus of a rock mass is presented. The newly proposed approach involves seven effective parameters (depth, rock quality designation, uniaxial compressive strength, the discontinuity density, the condition of discontinuities, the groundwater condition, and an adjustment for the orientation of discontinuities) pertinent to the deformation modulus of a rock mass, yet keeping simplicity as well. The performance of the RES model is compared with multiple regression models. The estimation abilities offered using RES and multiple regression models were presented by using field data obtained from road and railway construction sites in Korea. The results achieved indicate that the RES-based model predictor with the least mean square error and a higher coefficient of determination (R 2) performs better than the multiple regression models.

Characteristic Analysis of Concrete for Radiation Shielding Evaluation of Gamma Irradiation Facilities

Physical and chemical properties of concrete sample was obtained using various methods such as density analysis, elemental analysis and WD-XRF analysis to get accurate characteristics of concrete collected in our construction site in Korea. Using these results, in this study, we perform the simulation to compare the dose evaluation results between NBS concrete of ANSI/ANS 6.4.3 and characteristics of concrete samples using MCNPX. As a result, simulation results of collected concrete samples in our facility were underestimated up to 54.01%. Through these results, we verify the necessity of accurate properties of materials.

Agricultural Practice on the Korean Peninsula Taking into Account the Origin of Rice Agriculture in Asia

Based on Carl Sauer’s hypothesis that agricultural activity may have occurred fi rst with the domestication of tropical plants, rice was long thought to have originated in Southeast Asia, where the climate is very warm and humid, with plenty of rainfall. After many new archaeological sites with evidence of older cultivated rice were discovered throughout the 1980s and 1990s in China, agricultural scientists now generally consider the middle Yangtze River and Yunnan regions, which are farther north than Southeast Asia, as the cradle of the earliest rice cultivation. The dates and geographic locations of historic rice cultivation have been challenged even further after carbonized rice hulls were excavated from the Sorori Village in central South Korea. This paper introduces theoretical arguments related to the transition period from foraging to farming systems in Korean archaeology and regarding the origins of rice, which is currently the most important crop for Northeast Asian peoples. A brief survey of research results, the ecological conditions of Northeast Asia, the biological uniqueness of rice, and archaeological evidence for rice cultivation from the Sorori site in Korea suggests that while we do not have any strong reason to believe that there is only one center of agricultural and domestication processes, and multiple origins for domesticated rice are still conceivable, temporal and spatial frames for the early history of rice cultivation need to be expanded.

Trend of storm water runoff pollutants temporal variability from different land use sites in Korea

Trend of storm water runoff pollutants temporal variability from different land use sites in Korea

부유분진측정기(PM10) 관측 자료 실시간 품질관리 알고리즘 개발 및 평가

A real-time quality control algorithm for <TEX>$PM_{10}$</TEX> concentration measured by Continuous Ambient Particulate Monitor (FH62C14, Thermo Fisher Scientific Inc.) has been developed. The quality control algorithm for <TEX>$PM_{10}$</TEX> data consists of five main procedures. The first step is valid value check. The values should be within the acceptable range limit. Upper (<TEX>$5,000{\mu}g\;m^{-3}$</TEX>) and lower (<TEX>$0{\mu}g\;m^{-3}$</TEX>) values of instrument detectable limit have to be eliminated as being unrealistic. The second step is valid error check. Whenever unusual condition occurs, the instrument will save error code. Value having an error code is eliminated. The third step is persistence check. This step checks on a minimum required variability of data during a certain period. If the <TEX>$PM_{10}$</TEX> data do not vary over the past 60 minutes by more than the specific limit (<TEX>$0{\mu}g\;m^{-3}$</TEX>) then the current 5-minute value fails the check. The fourth step is time continuity check, which is checked to eliminate gross outlier. The last step is spike check. The spikes in the time series are checked. The outlier detection is based on the double-difference time series, using the median. Flags indicating normal and abnormal are added to the raw data after quality control procedure. The quality control algorithm is applied to <TEX>$PM_{10}$</TEX> data for Asian dust and non-Asian dust case at Seoul site and dataset for the period 2013~2014 at 26 sites in Korea.

다성분 반응 이동 모델링을 이용한 트리클로로에틸렌(TCE)으로 오염된 지하수에서의 자연저감 평가

To properly manage and remediate groundwater contaminated with chlorinated hydrocarbons such as trichloroethylene (TCE), it is necessary to assess natural attenuation processes of contaminants in the aquifer along with investigation of contamination history and aquifer characterization. This study evaluated natural attenuation processes of TCE at an industrial site in Korea by delineating hydrogeochemical characteristics along the flow path of contaminated groundwater, by calculating reaction rate constants for TCE and its degradation products, and by using geochemical and reactive transport modeling. The monitoring data showed that TCE tended to be transformed to cis-1,2-dichloroethene (cis-1,2-DCE) and further to vinyl chloride (VC) via microbial reductive dechlorination, although the degree was not too significant. According to our modeling results, the temporal and spatial distribution of the TCE plume suggested the dominant role of biodegradation in attenuation processes. This study can provide a useful method for assessing natural attenuation processes in the aquifer contaminated with chlorinated hydrocarbons and can be applied to other sites with similar hydrological, microbiological, and geochemical settings.

A Rapid, Accurate, and Efficient Method to Map Heavy Metal-Contaminated Soils of Abandoned Mine Sites Using Converted Portable XRF Data and GIS

The use of portable X-ray fluorescence (PXRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) increases the rapidity and accuracy of soil contamination mapping, respectively. In practice, it is often necessary to repeat the soil contamination assessment and mapping procedure several times during soil management within a limited budget. In this study, we have developed a rapid, inexpensive, and accurate soil contamination mapping method using a PXRF data and geostatistical spatial interpolation. To obtain a large quantity of high quality data for interpolation, in situ PXRF data analyzed at 40 points were transformed to converted PXRF data using the correlation between PXRF and ICP-AES data. The method was applied to an abandoned mine site in Korea to generate a soil contamination map for copper and was validated for investigation speed and prediction accuracy. As a result, regions that required soil remediation were identified. Our method significantly shortened the time required for mapping compared to the conventional mapping method and provided copper concentration estimates with high accuracy similar to those measured by ICP-AES. Therefore, our method is an effective way of mapping soil contamination if we consistently construct a database based on the correlation between PXRF and ICP-AES data.

Computational fluid dynamics simulations to optimize the filling of an underground mine cavity with fly ash

Subsidence caused by the underground spaces of abandoned mines is a potential danger to life and property. This study focuses on optimizing the filling of these cavities at a site in Korea to prevent subsidence and to reuse abandoned mine. Fly ash produced from thermoelectric power plants might be profitably used to fill the abandoned workings. Computational fluid dynamics (CFD) is used here to simulate fly ash injection into mine cavities by a volume-of-fluid method. The numerical experiments are run after the establishment of three input parameters, which are used to optimize two output parameters. This series of CFD simulations investigates the effects of filling with respect to the operation factors of the filling method. The filling operation is then optimized with regard to efficiency and equipment cost. A low injection point with drilling connection of vertical shafts gives the most efficient filling of underground mine cavities.

Application of the freeze-dried bioluminescent bioreporter Pseudomonas putida mt-2 KG1206 to the biomonitoring of groundwater samples from monitoring wells near gasoline leakage sites.

This study examined the applicability of a freeze-dried bioluminescent bioreporter, Pseudomonas putida mt-2 KG1206 (called KG1206), to the biomonitoring of groundwater samples. Samples were collected from the monitoring wells of gas station tanks or old pipeline leakage sites in Korea. In general, the freeze-dried strain in the presence of pure inducer chemicals showed low bioluminescence activity and a different activity order compared with that of the subcultured strain. The effects of KNO3 as a bioluminescence stimulant were observed on the pure inducers and groundwater samples. The stimulation rates varied according to the type of inducers and samples, ranging from 2.2 to 20.5 times (for pure inducers) and from 1.1 to 11 times (for groundwater samples) the total bioluminescence of the control. No considerable correlations were observed between the bioluminescence intensity of the freeze-dried strain and the inducer concentrations in the samples (R 2<0.1344). However, samples without a high methyl tertiary butyl ether (MTBE) level and those from the gas station leakage site showed reasonable correlations with the bioluminescence activity with R 2 values of 0.3551 and 0.4131, respectively. These results highlight the potential of using freeze-dried bioluminescent bacteria as a rapid, simple, and portable tool for the preliminary biomonitoring of specific pollutants at contaminated sites.

Measurement of the scCO2 Storage Ratio for the CO2 Reservoir Rocks in Korea

Based on the lab experiments, the average scCO2 storage ratio of the Janggi conglomerate was calculated at 31.2%, which can be used to evaluate the feasibility of the Janggi basin as a scCO2 storage site in Korea. Assuming that the average radius of the CO2 storage formations is 250 m and the average thickness of the formations under 800 m in depth is 50 m, the scCO2 storage capacity of the Janggi basin is larger than 400,000 tons, demonstrating that the Janggi basin has a great potential for use as a pilot scale test site for the CO2 storage.

Assessment of Photovoltaic Potentials at Abandoned Mine Reclamation Sites in Korea using Renewable Energy Resource Maps

Assessment of Photovoltaic Potentials at Abandoned Mine Reclamation Sites in Korea using Renewable Energy Resource Maps

Development of novel simple sequence repeat markers from ramie (Boehmeria nivea L. Gaudich) and analysis of genetic diversity in its genetic resources

Boehmeria nivea (ramie), a subshrub of the Urticaceae family and an important fiber crop, has been grown in Asian countries, including Korea, for many centuries. Traditionally, in some regions of Korea, ramie leaves are also used as a major ingredient in ‘Songpyeon’ rice cakes. Despite its economic importance, the molecular genetics of ramie have not yet been studied in detail. Researchers from Yeong-Gwang Agricultural Technology Center collected genetic resources of ramie from a variety of local sites in Korea. Nuclear internal transcribed spacer sequences amplified from 90 genetic resources showed no variation in size or sequence between them or B. nivea reference samples, indicating that all the genetic resources could be taxonomically classified as B. nivea. To systematically and efficiently manage these genetic resources, we developed simple sequence repeat (SSR) markers for ramie using the magnetic bead hybridization selection method. Finally, we selected 17 SSR markers that showed possible polymorphism among the genetic resources and analyzed the genetic diversity of ramie collection. These 17 markers detected a total of 140 alleles, ranging from 3 to 17 alleles per accession. The average genetic diversity value was 0.61, ranging from 0.37 to 0.84. Average polymorphism information content was 0.56, ranging from 0.34 to 0.82. Genetic cluster analysis based on SSR data revealed that the genetic collection of ramie plants could be classified into four distinct clusters. A purity test on several of the genetic resources using polymorphic SSR markers revealed that some resources were impure. These newly developed SSR markers might be useful for diverse genetic analysis including the management of genetic collections, establishment of core collections, and cultivar identification.

Automated Finite State Workflow for Distributed Data Production

In statistically hungry science domains, data deluges can be both a blessing and a curse. They allow the narrowing of statistical errors from known measurements, and open the door to new scientific opportunities as research programs mature. They are also a testament to the efficiency of experimental operations. However, growing data samples may need to be processed with little or no opportunity for huge increases in computing capacity. A standard strategy has thus been to share resources across multiple experiments at a given facility. Another has been to use middleware that “glues” resources across the world so they are able to locally run the experimental software stack (either natively or virtually). We describe a framework STAR has successfully used to reconstruct a ~400 TB dataset consisting of over 100,000 jobs submitted to a remote site in Korea from STAR's Tier 0 facility at the Brookhaven National Laboratory. The framework automates the full workflow, taking raw data files from tape and writing Physics-ready output back to tape without operator or remote site intervention. Through hardening we have demonstrated 97(±2)% efficiency, over a period of 7 months of operation. The high efficiency is attributed to finite state checking with retries to encourage resilience in the system over capricious and fallible infrastructure.

Development and Optimization of a Reverse Transcription Hemi-Nested PCR Primer for the Detection of Potato Mop-Top Virus at Quarantine Inspection Sites in Korea.

Potato mop-top virus (PMTV) is classified as a plant quarantine virus in Korea. It is tested at import inspection sites. In this study, two sets of reverse transcription-hemi-nested polymerase chain reaction primers were developed to diagnose PMTV. In addition, modified- positive control plasmid was developed for the identification of false positive results in plant quarantine. The assay is expected to be useful for improving the detection and diagnosis of PMTV.

ISH NIA PS 03-03 Masked hypertension prevalence and its related factor from two rural population sites in Korea

ISH NIA PS 03-03 Masked hypertension prevalence and its related factor from two rural population sites in Korea

속채움 콘크리트와 철근으로 보강된 대구경 합성 PHC말뚝의 휨성능 평가

최근 구조물의 대형화에 따른 큰 지지력의 말뚝에 대한 수요가 증가하는 추세이다. 이에 따라 기성 PHC말뚝의 경우에도 700~1,200 mm 범위의 대구경 말뚝에 대한 활용이 증가하고 있고 최근 국내 현장에 적용되고 있다. 이 연구에서는 대구경 PHC말뚝의 휨성능을 향상시키기 위해 철근과 콘크리트로 보강하여 합성 PHC말뚝을 제작하였다. 휨강도 평가는 4등분점 제하실험을 통해 변위제어 방법으로 수행되었다. 휨실험을 통해 LICPT 실험체 횡방향 철근의 변형률 분포를 분석한 결과 횡방향 철근의 배근은 전단균열의 진전과 균열폭 제어에 효과적인 것으로 나타났고, 복부전단균열 발생을 억제할 수 있었다. LICPT 실험체는 LICP 실험체 보다 휨강도가 약 1.08배, 중앙부 변위가 약 1.19배 증가하였고, 횡방향 철근의 배근은 말뚝의 연성적인 휨거동 확보에 유리한 것으로 나타났다. 말뚝 제작시 사용되는 각각의 재료가 휨강도에 기여하는 수준을 층상화 단면 해석으로 계산된 축강도-휨모멘트 상관도를 통해 평가하였다. 기성 PHC말뚝과 LICP 실험체의 실제 휨강도를 1.13배, 1.16배의 안전율로 예측할 수 있었다. A demand of high bearing capacity of piles to resist heavy static loads has been increased. For this reason, the utilization of large diameter PHC piles including a range from 700 mm to 1,200 mm have been increased and applied to the construction sites in Korea recently. In this study, in order to increase the flexural strength capacity of the PHC pile, the large diameter composite PHC pile reinforced by in-filled concrete and reinforcement was developed and manufactured. All the specimens were tested under four-point bending setup and displacement control. From the strain behavior of transverse bar, it was found that the presence of transverse bar was effective against crack propagation and controlling crack width as well as prevented the web shear cracks. The flexural strength and mid-span deflection of LICPT specimens were increased by a maximum of 1.08 times and 1.19 times compared to the LICP specimens. This results indicated that the installed transverse bar is in an advantageous ductility performance of the PHC piles. A conventional layered sectional analysis for the pile specimens was performed to investigate the flexural strength according to the each used material. The calculated bending moment of conventional PHC pile and composite PHC pile, which was determined by P-M interaction curve, showed a safety factor 1.13 and 1.16 compared to the test results.

Delimiting the species Neosiphonia yendoi (Rhodomelaceae, Rhodophyta) based on COI and rbcL genetic variation in Korea and Japan

Although the marine red algal genus Neosiphonia is well characterized, many species of Neosiphonia are poorly understood. To correctly define the species delimitation of Neosiphonia yendoi using genetic variation, owing to the confusion over identification with “N. sphaerocarpa” from Korea, we investigated intensively the haplotype network of the mitochondrial COI and the plastid rbcL genes of specimens collected from Korea and Japan. The molecular analyses indicated that specimens collected in different sites of Korea and Japan belong to the same species, Neosiphonia yendoi and “Neosiphonia sphaerocarpa” from Korea, which is distinguished from N. sphaerocarpa from Florida and is allied with N. yendoi collected from the type locality, Muroran of Japan. A total of 29 COI and 13 rbcL haplotypes were found and the COI haplotype network shows evidence of a clear break between specimens from Jeju Island and all other locations of Korea, suggesting the possibility of cryptic diversity within N. yendoi.

한국 수소 충전소 건설의 경제성 분석

As the hydrogen era comes near future, hydrogen fuel cell vehicles are core of hydrogen economy. Until now, Korea has 17 hydrogen refueling stations but 9 hydrogen refueling stations have been retired already and 8 hydrogen refueling stations are still running. With a limited number of hydrogen refueling stations, it is very difficult to get scientific data for the economy of hydrogen refueling stations in Korea. Thus, based on NREL(National Renewable Energy Laboratory) study, we analyzed most recent data for the construction of hydrogen refueling stations in one specific site in Korea. The cost comparison data between Korea and USA shows 14% difference, saying higher costs of Korea. Korea looks 5 years delay compared to USA. This data will be an important tool for the investment from every industrial parties.

기후변화 시나리오에 따른 미래 참다래 궤양병 피해 예측

RCP4.5와 RCP8.5 미래 기후 변화 시나리오자료와 참다래 궤양병 피해 예측 모형인 D-PSA-K, 미래 참다래 재배적지 지도를 활용하여 궤양병의 미래 피해를 예측하고 참다래 궤양병의 발생 변화의 경향성을 찾아 보았다. 병원 세균에 의한 감염이 충분히 있다는 가정 아래에서 RCP4.5와 RCP8.5 시나리오의 2020년대와 2050년대에서 궤양병의 최대이병주율은 제주도와 남해안 일부 지역을 제외한 대부분의 지역에서 75% 이상으로 나타날 것으로 예측되었다. 두 시나리오들 모두에서 월동기 저온 환경이 없다는 가정 아래에서의 참다래 궤양병에 의한 가지 피해량은 거의 모든 재배가능지에서 증가될 것으로 예측된 반면에 월동기 저온에 의한 가지 피해량 증가율은 거의 모든 재배가능지에서 감소할 것으로 예측되었다. 지역 및 시나리오별로 궤양병 피해의 증가 및 감소의 경향은 다르게 나타날 것으로 예측되었다. RCP4.5 시나리오에서 2050년대에 2020년대에 비하여 10% 이상 최대 이병주율의 증가가 일어날 것으로 예측된 참다래 재배 가능지는 전체 재배 가능지의 3.14%, RCP8.5 시나리오에서는 25.41%였다. We estimated the averaged maximum incidences of bacterial canker at suitable sites for kiwifruit cultivation in 2020s and 2050s using D-PSA-K model with RCP4.5 and RCP8.5 climate change scenarios. Though there was a little difference between the estimation using RCP4.5 and that using RCP8.5, the estimated maximum disease incidences were more than 75% at all the suitable sites in Korea except for some southern coastal areas and Jeju island under the assumption that there are a plenty of infections to cause the symptoms. We also analyzed the intermediate and final outputs of D-PSA-K model to find out the trends on the change in disease incidence affected by climate change. Whereas increase of damage to kiwifruit canes in a non-frozen environment caused by bacterial canker was estimated at almost all the suitable sites in both the climate change scenarios, rate of necrosis increase caused by the bacterial canker pathogen in a frozen environment during the last overwintering season was predicted to be reduced at almost all the suitable sites in both the climate change scenarios. Directions of change in estimated maximum incidence varied with sites and scenarios. Whereas the maximum disease incidence at 3.14% of suitable sites for kiwifruit cultivation in 2020s under RCP4.5 scenario was estimated to increase by 10% or more in 2050s, the maximum disease incidence at 25.41% of the suitable sites under RCP8.5 scenario was estimated so.

Effect of phytoplankton biomass in seawater on chemical properties of sea spray aerosols

This study is to investigate the effect of biological seawater properties on sea spray aerosols (SSA). Concentrations of chlorophyll-a and bacteria were measured at coastal site in Korea in fall and summer seasons. Also, aerosol mass spectrometer (AMS) was used to determine chemical constituents (organics, sulfate, nitrate, ammonium, and chloride) of non-refractory submicrometer aerosols sprayed from seawaters using a bubble bursting system. The average concentration of chlorophyll-a in seawater in fall was 1.75±0.78μg/l, whereas it significantly increased to 5.11±2.16μg/l in summer. It was found that the fraction of organics in the submicrometer SSA was higher in summer (68%) than fall (49%), and that the organic fraction in the SSA increased as the concentration of chlorophyll-a increased in seawater, suggesting that the high phytoplankton biomass in seawater could lead to the enhancement of organic species in the SSA.