송이 균환내 토양수분의 시공간적 변화

구창덕 ( Gu Chang Deog ),김재수 ( Kim Jae Su ),이상희 ( Lee Sang Hui ),박재인 ( Park Jae In ),안광태 ( An Gwang Tae ) 한국산림과학회 2003 한국산림과학회지 Vol.92 No.6

Water is critically important for Tricholoma matsutake(Tm) growth because it is the major component of the mushroom by over 90%. The mushroom absorbs water through the below ground hyphal colony. Therefore, the objectives of our study were to investigate spatio-temporal water changes in Tm colonies. This study was carried out at Tm fruiting sites in Sogni Mt National Park, where the below-ground fairy-ring colonies have been irrigated. To identify spatial water status within the Tm soil colony soil moisture and ergosterol content were measured at six positions including a mushroom fruiting position on the line of the colony radius. To investigate temporal soil moisture changes in the soil colony, Time Domain Reflectometry(TDR) sensors were established at the non-colony and colony front edge, and water data were recorded with CRlOX data logger from late August to late October. Before irrigation, whereas it was 12.8% at non-colony, the soil water content within Tm colony was 8.0% at 0-5cm from the colony front edge, 6.2% at 10-15cm and 6.5-7.5% at 20-40cm. And the content was 12.1% at 80cm distance from the colony edge, which is similar to that at the non-colony. In contrast, ergosterol content which is proportional to the live hyphal biomass was only 0.4pg/g fresh soil at the uncolonized soil, while 4.9 ㎍/g fresh soil at the front edge where the hyphae actively grow, and 3.8 .㎍/g fresh soil at the fruiting position, l.l ㎍/g at 20cm distance and 0.4㎍/g in the 40cm rear area. Generally, in the Tm fungal colony the water content changes were reversed to the ergosterol content changes. While the site was watered during August to October, the soil water contents were 13.5-23.0% within the fungal colony, whereas it was 14.5-26.0% at the non-colony. That is, soil water content in the colony was lower by 1.0-3.0% than that in the non-colonized soil. Our results show that Tm colony consumes more soil water than other parts. Especially the front 30cm within the hyphal colony parts is more critical for soil water absorption.

Calculation of GHGs Emission from LULUCF-Cropland Sector in South Korea

Park, Seong-Jin,Lee, Chang-Hoon,Kim, Myung-Sook,Yun, Sun-Gang,Kim, Yoo-Hak,Ko, Byong-Gu 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.6

he land use, land-use change, and forestry (LULUCF) is one of the greenhouse gas inventory sectors that cover emission and removals of greenhouse gases resulting from land use such as agricultural activities and land use change. Particularly, LULUCF-Cropland sector consists of carbon stock changes in soil, $N_2O$ emissions from disturbance associated with land use conversion to cropland, and $CO_2$ emission from agricultural lime application. In this paper, we conducted the study to calculate the greenhouse gases emission of LULUCF-Cropland sector in South Korea from 1990 to 2014. The emission by carbon stock changes, conversion to cropland and lime application in 2014 was 4424, 32, and 125 Gg $CO_2$-eq, respectively. Total emission from the LULUCF-Cropland sector in 2014 was 4,582 Gg $CO_2$-eq, increased by 508% since 1990 and decreased by 0.7% compared to the previous year. Total emission from this sector showed that the largest sink was the soil carbon and its increase trend in total emission in recent years was largely due to loss of cropland area.

태극권의 원리에 관한 연구

김창룡,박종구 龍仁大學校 武道硏究所 2004 武道硏究所誌 Vol.15 No.1

This study set out to investigate if the many different schools were different as much as they looked different on the outside or if they still shared the same contents in the theories of Taijiquan despite the different appearances by comparing the histories, theories, and Quanjia(拳架) of the schools with the focus on Chenjia-taijiquan(陳家太極拳). It also aimed to confirm the results of the consideration of the histories and theories by comparing each school's Taijiquan(太極拳) and Quanjia(拳架). The findings were as follows: 1) The sameness and the difference in the aspect of history of Taijiquan(太極拳) Taijiquan was reviewed from the origin to the differentiation and development. As a result, today's Taijiquan was the product of the original form practiced in Chenjiagou(陳家溝) being completed as the modern Taijiquan and gradually distributed and spread outside. The review of the history of Taijiquan revealed that it accomplished more fresh developments in many aspects after it was being distributed outside than it was limited within the region of Chenjiagou(陳家溝) and the Chen family. First, there were developments and systematization in terms of theories. It should be acknowledged that all the theoretical establishments were already prepared as the modern Taijiquan(太極拳) began to form in Chenjiagou(陳家溝). What is argued here is that it was after Taijiquan moved out of Chenjiagou(陳家溝) that the theoretical systems turned more refined and systematic. In other words, there was already a complete set of the secrets in which all the experiences and know-how from Chen wang-ting(陳王延) and Chen chang-xing (陳長興2) were accumulated for generations even in the era of Chenjiagou(陳家溝). But the secrets and tricks of the original Chenjiagou(陳家溝) enjoyed a lot of boons only after Wu yu-xiang(武禹襄) and Li yi-yu(이역여) integrated the theories of Greate Absolute and yin and yang(太極陰陽) into the Taijiquan(陳家溝) and thus the name of Taijiquan(陳家溝) was appointed as the official name. The biggest driving force that made all those happen was the wide spread of Taijiquan(太極拳3), which was backed up by the refined concerning writings by the addition of literary men and noblemen to the group of Taijiquan. Second, there were more than the theories that were under mutual influences after Taijiquan being spread outside. In the process of Taijiquan 's differentiation and development, Dajia(大架) and Xiaojia(小架) were established by Chenjia-taijiquan(陳家太極拳), which in turn exchanged mutual impacts with other schools that were being formed and drew and absorbed the influences from other schools. As a result, the appearances of Taijiquan became different somewhat along with the interpretations of the terms, but the basic mental techniques of Taijiquan seemed to be shared among the different schools. Thus there would be no opposition to saying that Taijiquan(陳家溝) could be used to refer to all the different schools with seemingly different appearances. The sameness and the difference in the aspect of theories of Taijiquan(陳家溝) The Taijiquan(太極拳) theories of each school were compared. As a result, having originated from the traditions represented by the Quanjing(拳經) of Qi ji-guang(威繼光), the concerned theories earned a new creative slogan called Taijiquan thanks to Chen wang-ting(陳王延). With the Chenjiagou(陳家溝) as the tradition, the outside creations followed their own growing path being represented by Wang zong-yue(王宗岳) and Wu yu-xiang(武禹襄). Then the concerned theories and creations combined together as the situations of the times changed, which results corresponded to the findings according to the chronological order. There was a strong sense of the process of thesis-antithesis-synthesis, where new creations were made based on the traditions, then the traditions were separated from the creations, and then there was another combination together. In today's world, there are many different schools of Taijiquan, which are operated in the same principles and rules based on the common roots. That should be the reason why Taijiquan can be nothing but Taijiquan no matter differences there are among the schools. The flow in the history has resulted in the different styles of five major schools of today's Taijiquan, which still have common features in the body and limb principles and rules. Thus it was confirmed that Taijiquan has not evolved into different types of Taijiquan based on the appearances but taken different outside forms according to the goals of practicing and spreading it or the degree of cultivation and tastes of Taijiquan people. The sameness and the difference in the aspect of each school's Taijiquan(太極拳) based on the Quanjia(拳架 comparison The Quanjia(拳架)(Taolu 套路) of each school was compared in the composition and common Zhaoshi(超式) in order to compare their Taijiquan. As a result, even though the names of Zhaoshi(超式) were changed and went through partial omission, replacement, alteration, addition, and simplification, the Taijiquan of each school turned out to share the same family line based on the Laojia(老架) of Chenjia-taijiquan(眞家太極拳). Then going into details of Zhaoshi(招式) led to the selection and comparison of several Zhaoshi(招式). After the comparison methods and scopes were decided, it was investigated what caused the outside changes to Taijiquan(太極拳). The results confirmed that even though the Zhaoshi(太極拳) of each school that originated from Chenjia-taijiquan(陳家太極拳) appeared very much different from the outside, they shared the same implications on the inside. It would be reasonable to argue that the outside appearances that seemed very much different in the overall structure or individual Zhaoshi(招式) were the products of each school's responding to the needs for spreading their Taijiquan for survival. That is, they just tried to pursue "Eungmuljayean(應物自然 : means unify with every object in nature)" of Taijiquan(太極拳) by taking proper measures responding to the changing situations of the times. In short, there were changes that led to the partial differences of some schools in appearance due to the creative growth and differentiation of Taijiquan(太極拳) itself in terms of theories and practice or some alterations that led to the simpler Taijiquan(太極拳) for the purpose of distribution. Despite the outside differences, however, the changes of each school remained royal to the essential meaning of Taijiquan(太極拳). Thus it's a reasonable argument that each school including not only Laojia(老架), Paochui(포추), Xinjia(新架), and Xiaojia(小架) of Chenjia-taijiquan(陳家太極拳) but also Yangia(楊家), Wujia(吳家), Wujia(武家), and Sunjia(孫架) all belongs to the same Taijiquan(太極拳) in contents.

Calculation of GHGs Emission from LULUCF-Cropland Sector in South Korea

Seong-Jin Park,Chang-Hoon Lee,Myung-Sook Kim,Sun-Gang Yun,Yoo-Hak Kim,Byong-Gu Ko 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.6

The land use, land-use change, and forestry (LULUCF) is one of the greenhouse gas inventory sectors that cover emission and removals of greenhouse gases resulting from land use such as agricultural activities and land use change. Particularly, LULUCF-Cropland sector consists of carbon stock changes in soil, N₂O emissions from disturbance associated with land use conversion to cropland, and CO₂ emission from agricultural lime application. In this paper, we conducted the study to calculate the greenhouse gases emission of LULUCFCropland sector in South Korea from 1990 to 2014. The emission by carbon stock changes, conversion to cropland and lime application in 2014 was 4424, 32, and 125 Gg CO₂-eq, respectively. Total emission from the LULUCF- Cropland sector in 2014 was 4,582 Gg CO₂-eq, increased by 508% since 1990 and decreased by 0.7% compared to the previous year. Total emission from this sector showed that the largest sink was the soil carbon and its increase trend in total emission in recent years was largely due to loss of cropland area.

공극 매질체에서 이온강도의 변화에 따른 박테리아의 부ㆍ탈착

이창구 ( Lee Chang-gu ),박성직 ( Park Seong-jik ),김현정 ( Kim Hyon-chong ),한용운 ( Han Yong-un ),김성배 ( Kim Song-bae ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

Column experiments were performed to investigate the influence of ionic strength on the attachment and detachment of Staphylococcus aureus to quartz sand and iron-coated sand. Experimental results showed that the mass recovery in quartz sand decreased with increasing ionic strength and bacteria detachment was occurred when ionic strength was changed. In the coated sand, however, the mass recovery remained constant even though ionic strength was changed. Also, no detachment occurred with ionic strength change.

연구논문 : HEC-RAS 모델을 이용한 신천 시험유역의 하도 특성연구

박병기 ( Byeong Ky Park ),이명구 ( Myung Gu Lee ),홍창수 ( Chang Su Hong ),이재관 ( Jae Kwan Lee ),이영준 ( Young Joon Lee ),최중대 ( Joong Dae Choi ) 한국환경과학회 2016 한국환경과학회지 Vol.25 No.1

In recent localized heavy rainfalls have been arising from abnormal climate change. People are concerning about damages with increasing the frequency of flooding. Therefore, we need to understand river hydraulic characteristics and management to reduce damage from flooding. To study hydraulic characterization of Sincheon experimental catchment HEC-RAS (Hydrologic Engineering Center River Analysis System) model which provided by U.S Army Corps of Engineers (USACE) was applied. This study analyzed and compared water level the frequency flood for 100 years and 200 years by clark unit Hydrography. The change of the water level of Daejeon bridge, Sincheon bridge and Singi bridge showed increased for all conditions. The flow rate for the Daejeon bridge and the Sincheon bridge showed an increase, but the Sinki bridge showed a decreasing flow rate overally, except for 1hour-100 years. The verification result showed that the model was able to simulate the water level with 0.4709 coefficient of determination and error ration ranging from 1 to 3%.

오스테나이트계 Fe-Ni based 합금강의 열화 시간에 의한 탄화물 거동과 기계적 물성 변화에 대한 연구

김기근(Keekeun Kim),박수(Soo Park),석창성(Chang-Sung Seok),최재구(Jae Gu Choi),김가연(Gayeon Kim) 대한기계학회 2018 大韓機械學會論文集A Vol.42 No.11

Fe-Ni-Cr 오스테나이트계 합금강 중 NCF3015 소재는 Ni 원소의 함량을 증가시켜 고온 기계적 물성을 우수하게 만든 소재이다. 고온 기계적 물성은 미세조직의 형상과 밀접한 관계가 있으며 미세조직의 형상은 고온노출 온도와 시간에 따라 변할 수 있기 때문에, 재료의 고온 미세조직 변화와 기계적 물성변화에 대한 연구가 필요하다. 본 연구에서는 950℃에서 NCF3015 소재의 열화 시간에 따른 미세조직 및 탄화물 변화와 기계적 물성과의 관계를 분석하기 위해 Thermo-calc 프로그램을 통한 평형 상태도 해석으로 NCF3015 소재의 고온 미세조직 변화를 예측하였으며, 실험적으로 열화된 시편의 미세조직 분석을 통해 해석결과와 비교하였다. 또한 인장시험과 비커스 경도를 측정함으로써 열화 시간에 따른 기계적 물성변화를 분석하였으며 이를 탄화물 거동변화와 관련 지어 두 변화의 상관관계를 도출하였다. NCF3015 is a Fe-Ni-Cr austenitic alloy steel that increases the content of Ni elements and which results in excellent high-temperature mechanical properties. High-temperature mechanical properties are closely related to the microstructure, and the shape of the microstructure can be changed by the exposure temperature and time. Therefore, it is necessary to study the changes in the high-temperature microstructure and mechanical properties of materials. In this research, to analyze the relationship between microstructural and carbide changes, as well as the mechanical properties of NCF3015 at 950℃, an equilibrium-state analysis is performed using the Thermo-calc program to determine the microstructural changes. The results are compared with the experimental results obtained. In addition, the tensile test and the Vicker"s hardness test are conducted to determine the variation in the mechanical properties with degradation time, which was correlated with the changes of microstructural and carbide behavior.

한ㆍ일 도시가스산업의 생산성 비교분석

최인수(In Su Choi),도범성(Bum Sung Do),박창수(Chang Soo Park),박중구(Jung Gu Park) 한국가스학회 2009 한국가스학회지 Vol.13 No.2

본고는 21세기 들어 고유가와 기후변화협약에 대응하여 중요성이 더해지고 있는 한국과 일본의 도시가스기업의 생산성을 분석하였다. 맘퀴스트 생산성 지수(Malmquist Productivity Index: MPI)를 통해 1997년부터 2005년까지 한국 30개, 일본 5개 기업들의 재무제표를 활용하여 기간 전체로, 그리고 수요의 구조변화를 나타내었던 2000년을 기준으로 이전과 이후의 생산성을 평가하였다. 분석의 결과, 첫째, 1996년~2005년 전체 기간의 MPI 누적지수에서 한국의 도시가스산업이 일본보다 상위에 있는 것으로 분석되었다. 그러나 기간별로 본 MPI 개선효과는 일본의 경우 1997~2000년 동안 -1.03%에서 2001~2005년 동안에는 -1.72%로 근소한 차이를 나타낸 반면, 한국의 경우에는 전반기 0.37%(금융외환위기를 경험한 98년 제외시 0.80%)이었지만 후반기에 -0.60%로 악화된 것으로 나타났다. 둘째, 후반기 한국의 MPI 악화는 기술적 효율성 지수보다는 기술변화 지수가 전반기 -0.88%(98년 제외시 0.29%)에서 후반기 -1.29%로 크게 악화된 것에 기인하는 것으로 분석되었다. 이에 따라 한국의 도시가스사업은 2001년 이후 악화되고 있는 생산성 증가율과 악화의 요인이 되고 있는 기술변화를 개선하는 정책적 노력이 필요하다. This article makes a comparative analysis on the productivity in gas distribution industry between Korea and Japan, using Malmquist productivity index(MPI). The estimated MPI during 1997~2005 shows that the productivity of Korean gas distribution industry has been generally higher than that of Japanese gas distribution industry. But Korean MPI made a drastic change from positive improvement (+ 0.37) during 1997~2000 to severe deterioration (-0.60) during 2001~2005, while Japan MPI has seldom changed. This change of Korean MPI is analyzed to result from the worsening of technical change rather than technical efficiency change. According to this result, Korean gas distribution industry needs to improve the technical change.

전기화학적 방법을 이용한 수소제거에 관한 연구

박창규,김재홍,김정구,안승호,박진석,김종성,진태은 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.3

Hydrogen embrittlement (HE) mitigation on the low alloy steel was studied using electrochemical technique. This method can be applied to reduce HE susceptibility. Hydrogen induced cracking (HIC) characteristics of the low alloy steel was investigated in aerated and deaerated borate buffer solution (0.3M H₃BO₃ + 0.074M N₂B_(4)O_(7), pH 8.4). The electrochemical properties of the low alloy steel showed passive behavior in this environment. By performing galvanostatic and potentiostatic test, hydrogen was charged and discharged to specimens respectively. By applying the potential of +630 mV_(SCE), the accumulated hydrogen was eliminated electrochemically. A specimen discharged for 24h indicated the efficiency of the hydrogen discharge up to 99.9%. Slow strain rate tests (SSRT) results showed that a specimen with higher hydrogen concentration revealed inferior mechanical properties such as shorter time to fracture, lower elongation, ultimate tensile strength and yield strength values. Furthermore, SEM fractographs revealed that the higher the hydrogen concentration is, the more probable the features of brittle fracture are. (Received July 26, 2004)

Cu-6Ni-4Sn 합금에서 Cr 첨가에 따른 전기화학적 특성에 관한 연구

박창규,김정구,안승호,한승전 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.3

Corrosion characteristics of Cu-6%Ni-4%Sn-x%Cr alloys in a acid-chloride solution (0.1M H₂SO₄+ 0.0056M NaCl) at pH = 6, were studied as a function of chromium addition. Three kinds of Cu-6%Ni-4%Sn-x%Cr alloys were prepared by melting, and casting, followed by thermomechanical treatments. The corrosion behavior of Cu-6%Ni-4%Sn-x%Cr alloys was investigated by electrochemical corrosion tests (potentiodynamic polarization test, electrochemical impedance spectroscopy) and surface analyses (optical microscopy, electron probe micro analysis, scanning electron microscopy). Cr additions were found to prevent the localized corrosion behavior. This is the reason that the small addition of Cr promoted the decomposition behaviors of the supersaturated solid solution a in Cu-6%Ni-4%Sn alloy, i.e., the number of like-Sn-rich carbide impurities (LCI), which increased the galvanic effect between the matrix and the LCI, decreased with increasing the Cr addition. (Received September 8, 2004)