문경지역에 분포하는 화강암의 미세균열 발달특징

이병대 강원대학교 자원개발연구소 1998 자원개발연구 Vol.13 No.-

Theoretical Analysis for Nitrogen Removal in Step Feed Oxic-Anoxic-Oxic Process

이병대,김일출 한국응용과학기술학회 2008 한국응용과학기술학회지 Vol.25 No.3

One of the popular domestic sewage treatment process (called step feed oxic-anoxic-oxic process) for nitrogen removal was analyzed in this study by theoretical analysis based on the nitrification and denitrification reaction. Total nitrogen removal efficiency was suggested by considering influent qualities(i.e., ammonia, nitrite, nitrate, alkalinity, and COD). Total nitrogen removal efficiency depends on r (influent allocation ratio). In the case that all influent components are enough, the total nitrogen removal follows equation 100b/(1+b), when r is 1/(1+b). Finally, it can be concluded that step feed oxic-anoxic-oxic process could be effective for nitrogen removal.

Occurrence of Dry Rot on Cymbidium Orchids Caused by Fusarium spp.in Korea

이병대,조원대,성재모,WanGyuKim 한국식물병리학회 2002 Plant Pathology Journal Vol.18 No.3

Cymbidium orchids with blight and rot symptoms were collected, and a total of 63 isolates of Fusarium spp. was obtained from pseudobulbs, roots, and leaves of the diseased plants. The isolates were identified based on their morphological characteristics. Out of the 63 isolates of Fusarium spp., 51 isolates were identified as F. oxysporum, 10 isolates as F. solani, and the rest as F. proliferatum. F. oxysporum was isolated from all the Cymbidium spp., while F. solani and F. proliferatum were isolated only from Cymbidium ensifolium and C. ginatum, respectively. Isolates of the three Fusarium spp. were tested for pathogenicity to their hosts by artificial inoculation. The strongly pathogenic isolates of Fusarium spp. induced severe dry rot of pseudobulbs and roots of the host plants. The symptoms progressed up to the basal part of the leaves, which later caused blight of the entire plant. The dry rot symptoms induced on the plants by artificial inoculation with the isolates of Fusarium spp. were similar to those observed in the growers' greenhouses. This is the first report of dry rot of Cymbidium spp. caused by F. oxysporum, F. solani, and F. proliferatum in Korea.

Relationship between groundwater and climate change in South Korea

이병대,함세영,장성,정재열,김규범 한국지질과학협의회 2014 Geosciences Journal Vol.18 No.2

Climate change has resulted in a gradual increase inthe surface temperature and significantly variable precipitation indifferent regions of the world. Linear regression of the groundwaterlevels in Korea between 2000 and 2010 revealed a decreasingtrend with a slope of –29.2 mm/yr; –29.6 mm/yr in the wet seasonand –32.0 mm/yr in the dry season. Mann-Kendall and Sen’s testswere carried out using the groundwater levels and groundwatertemperatures at 78 locations in South Korea between 2000 and2010. The groundwater levels showed a trend in ~50% of the 78groundwater level datasets, of which ~70% exhibited a decreasingtrend at the 95% confidence level. This decreasing trend in thegroundwater levels appears to be related to a change in the precipitationin South Korea because more abundant rainfall in thewet season each year does not contribute significantly to groundwaterrecharge, whereas less rainfall that occurs in the dry season cancause a decrease in the groundwater level. Linear regression of thegroundwater temperatures revealed a slope of 0.1006 °C/yr between2000 and 2010 with a gentler slope (0.08 °C/yr) in summer (June–September), showing that the increase in surface temperature hasan impact on increasing the groundwater temperature. In this situationof climate change in Korea, the paradigm of groundwatermanagement strategy needs to be altered properly.

Reuse of HPLC Guard Column by Ultrasonic Cleaning

이병대 한국응용과학기술학회 2016 한국응용과학기술학회지 Vol.33 No.3

This study investigated reusability of costly guard column by ultrasonic. It alsoinvestigated various effects that affect to guard column generation by ultrasonic. When investigated30 KHz of frequency, area of ascorbic acid is 73.0% compared to unused guard column. As aresult of investigation of effect of pH, guard column by ultrasonic is effective at alkali area. As aresult of investigation of solvent effect, when ethanol is used, generation rate is 81.9% as of peakarea compared to the case of analysis in un used column. From the result, it indicates thatregenerated guard by ultrasonic is reusable.

도수로터널 주변 지역의 지하수 유동성 단열 규명

이병대,이인호,추창오,함세영,성익환,황세호 한국지하수토양환경학회 2002 지하수토양환경 Vol.7 No.4

도수로터널 주변 지역의 대수층에 대한 유동성 단열을 규명하기 위하여 야외시험이 실시되었다. 단열들에 대한 정보를 얻기 위하여 지표 지질조사 지질구조조사 및 초음파주사검층을 실시하였다. 지표에서의 단열발달은 퇴적암의 층리면과 층리절리 및 화강암류의 판상절리와 같은 저각의 경사를 가지는 부분과 75$^{\circ}$ 이상의 고각의 경사를 가지는 부분의 두 개의 뚜렷한 단열군으로 형성되어 있다. 층리절리와 판상절리의 평균 주향과 경사는 각각 N70-80$^{\circ}$W.25$^{\circ}$SW, N35$^{\circ}$W.12$^{\circ}$NE이다. 고각의 절리들은 퇴적암 지역에서는 N80$^{\circ}$W.70-85$^{\circ}$SW와 N$10^{\circ}$E.85$^{\circ}$SE 두 방향의 단열조가 우세하며, 화산암 및 화강암 지역은 N40-50$^{\circ}$.E 85$^{\circ}$SE/85$^{\circ}$NE, N70$^{\circ}$E.80$^{\circ}$SE, 그리고 N70-75$^{\circ}$W.80$^{\circ}$SW 방향의 단열조가 우세하게 발달한다. 초음파주사검층에 의하여 얻어진 시추공내의 단열들은 N60-80$^{\circ}$W.20-45$^{\circ}$SW, N10-35$^{\circ}$E.64-83$^{\circ}$SE, N40-65$^{\circ}$E.60-85$^{\circ}$SE, N70$^{\circ}$E.80$^{\circ}$SE, N60-80$^{\circ}$W.45-85SE/SW의 단열군들이 우세하다. 공내 수리전도도의 수직적인 분포를 파악하기 위하여 정압주입시험을 실시하였다. 계산된 수리전도도는 3.363E-10 m/sec 에서 2.731E-6 m/sec의 범위로서 최대값과 최소값은 4차수(four order)의 차이를 보였다. 단열대의 분포 특성을 파악하기 위하여 지구물리검층을 실시하였고, 각 시험에 의해 획득된 결과들과의 비교를 통하여 유동성이 높은 단열들이 규명되었다. 온도검층은 유동성 단열과 일반적인 단열들을 구별하는 좋은 지시자로 나타났다. 그 결과, N70-80$^{\circ}$W.60-85$^{\circ}$NE/SW, N75-80$^{\circ}$W.25-30$^{\circ}$SW, N50-64$^{\circ}$W.60-85$^{\circ}$NE, N35-45$^{\circ}$E.65-75$^{\circ}$SE, 그리고 N65-72$^{\circ}$E.80$^{\circ}$SE/60$^{\circ}$NW의 단열들이 연구지역의 지하수 흐름을 지배하는 뚜렷한 유동성 단열로 규명되었다. A field technique for assessing the transmissive fractures in an aquifer was applied to a fractured rock formation in Youngchun area Korea. Geological mapping and detailed acoustic borehole teleview(BHTV) logging were performed to obtain information about the fractures. The study area consists predominantly of two types of fractures. The fracture sets of low angle partings such as bedding and sheeting plains have strike N70-80$^{\circ}$W, 25$^{\circ}$-30$^{\circ}$SW and N3S$^{\circ}$W, 12$^{\circ}$NE, respectively. In areas of high fractures, on the other hand, the major fracture sets show strike N80$^{\circ}$W and dip 70$^{\circ}$-85$^{\circ}$SW, N10$^{\circ}$E.85$^{\circ}$SE in sedimentry rocks, N40-50$^{\circ}$E.85$^{\circ}$SE/85$^{\circ}$NE, N70$^{\circ}$E.80$^{\circ}$SE, and N7$^{\circ}$-75$^{\circ}$W.80$^{\circ}$SW in granites and volcanic rocks. Injection tests have been performed to identify discrete production zones and quantify the vertical distribution of hydraulic conductivity. The calculated hydraulic conductivities range from 3.363E-10 to 2.731E-6, showing that the difference between maximum and minimum value is four order of magnitude. Dominant section in hydraulic conductivity is extensively fractured. Geophysical logging was carried out to clarify characterization of the distribution of fracture zones. Transmissive fractures were evaluated through the comparison of the results obtained by each method. The temperature logs appeared to be a good indicator that can distinguish a high transmissive fractures from a common fractures in hydraulic conductivity. In numerous cases, evidence of fluid movement was amplified in the temperature gradient log. The fracture sets of N70-80$^{\circ}$W.60-85$^{\circ}$NE/SW N75-80$^{\circ}$W.25-30$^{\circ}$SW, N50-64$^{\circ}$W.60-85$^{\circ}$NE, N35-45$^{\circ}$E.65-75$^{\circ}$SE, and N65-72$^{\circ}$E.80$^{\circ}$SE/60$^{\circ}$NW were idenfied as a distinct transmissive fractures through the results of each tests.

Estimation of Optimal Operation Conditions in Step Feed Processes Based on Stoichiometric Nitrogen Removal Reactions

이병대 한국응용과학기술학회 2011 한국응용과학기술학회지 Vol.28 No.1

Step feed process was analyzed stoichiometrically for the optimal operation conditions in this study. In case of optimal operation conditions, minimum R (sludge recycling) value, r (internal recycling ratio) value, and n (influent allocation ratio) value for the step feed process to acquire the maximum TN removal efficiency were identified by theoretical analysis. Maximum TN removal efficiency, based on stoichiometric reaction, can be obtained by controlling n value for the step feed process.

터널굴착 공사에 따른 지하수 유출량과 수리지질학적 특성

이병대,조병욱,성익환 한국터널지하공간학회 2002 자연, 터널 그리고 지하공간 Vol.4 No.1

인삼탄저병균에 대한 인삼보호효과를 나타내는 신규미생물

이병대,밝훈,신점호,허회정,조현주 고려인삼학회 2011 고려인삼학회 학술대회 Vol.2011 No.4

울산지역 토지이용도에 따른 지하수 수질 및 오염특성

이병대,윤욱,성익환,Lee, Byeong-Dae,Yun, Uk,Sung, Ig-Hwan 한국지하수토양환경학회 2007 지하수토양환경 Vol.12 No.6

The groundwater chemistry is heavily influenced by land use. This study has investigated the groundwater quality and contamination characteristic associated with land use. Contamination index ($C_d$) was estimated for evaluating and areal distribution of groundwater contamination degree. Groundwater samples collected from 216 locations in the study area show great variability in chemical composition. Electrical conductance ranges from 100 to $31,360\;{\mu}S/cm$. The pH values are between 4.6 (acidic) and 8.57 (weak alkaline). The water types predominantly represent the $Ca-HCO_3$ and $Ca-Na-HCO_3$ types, whereas, in the residential and business areas, the water type is shifted to (Na, Ca)-Cl type with rich concentration of Cl. The $C_d$ values of the study area range from 1.1 to 117.6 with a mean of 9.56. 금번 연구에서 울산지역의 토지이용도에 따른 지하수 수질 및 오염특성을 파악하고, 지하수의 오염 정도를 평가하고 도면으로 시각화하는 방법인 오염지수를 산출하였다. 연구지역내 216개 시료에 대한 지하수의 화학조성은 매우 다양하게 나타나며, 전기전도도의 경우, $100{\sim}31,360\;{\mu}S/cm$로 매우 큰 변화를 보이고 있다. pH값은 $4.6{\sim}8.57$의 범위로 산성 내지 약알카리를 보이며 평균값은 7.0이다. 연구지역 지하수의 화학조성은 토지용도에 따라 많은 영향을 받는 것으로 해석되었다. 수질유형은 $Ca-HCO_3$, $Ca-Na-HCO_3$, 유형이 우세하며, 주거/상업지역과 공업지역 지하수의 경우는 농업지역과 녹지지역 지하수에 비해 Cl이 풍부한 (Na, Ca)-Cl 유형으로 변하고 있다. 연구지역 오염지수의 범위는 $1.1{\sim}117.6$으로 평균은 9.56으로 산출되었다.