느타리버섯 수확후 배지를 이용하여 표고 톱밥배지로 활용하기 위한 연구 수행결과 다음과 같다. 느타리버섯 수확후 배지를 톱밥 첨가량의 20~50%로 4처리로 혼합하여 분석한 결과 C/N은 62~76으로 나타났다. 느타리버섯 수확후 배지 첨가구는 대조구에 비해 질소와 폴리페놀 함량은 상대적으로 높고, 과당과 유기산 함량은 낮은 경향이었다. 특히, 미강이 첨가되지 않은 50% 처리구는 과당, 유기산 함량이 현저하게 낮았다. 초발이기간은 20, 25%가 7일로 대조구와 같았으나 30%와 50%는 각각 6일, 11일로 대조에 비해 각각 1, 4일 지연되었다. 표고버섯 3주기 수량은 20% 처리구가 268.7 g으로 대조와 비슷하였으나 첨가수준이 높을수록 감소하여 특히, 50% 첨가구에서는 버섯 발생이 거의 이루어지지 않았다. 따라서 느타리버섯 수확후 배지를 표고 배지로 이용하기 위해서는 톱밥 첨가량의 20% 수준이 바람직할 것으로 생각된다.

On November 15, 2017, Pohang earthquake occurred. Its local magnitude was announced to be ML=5.4 by Korea Meteorological Administration (KMA). Ground motion data recorded at KMA stations were obtained from their data bases. From the data, horizontal and vertical response spectra, and V/H ratio were calculated. The horizontal spectra were defined as GMRotI50 spectra. From the statistical analysis of the GMRotI50 spectra, a mean plus one standard deviation spectrum in lognormal distribution is obtained. Regression analysis is performed on this curve to determine the shape of spectrum including transition periods. Applying the same procedure, the shape and transition periods of vertical spectrum were obtained. These results were compared with the Korean standard design spectra, which were developed from domestic and overseas intra-plate earthquake records, and Gyeongju earthquake response spectra. The response spectra of Pohang earthquake were found to be almost identical with the newly proposed design spectra. Even the V/H ratios showed good agreement. These results confirmed that the method adopted when developing the standard design spectra were valid and the developed design spectra were reliable.

백령버섯 병재배용 배지 주재료는 콘코브 배지보다는 미루나무톱밥 배지 처리구에서 발이 및 생육특성이 가장 양호하였으며, 배지 영양원으로는 면실피, 면실박, 밀기울, 옥수수분, 미강 등이 적합하였고, 배지 혼합 비율은 58% 이내 범위에서 재료별로 질소함량을 고려하여 가감 사용하는 것이 적당하였으며, T-N 함량이 높은 면실박 사용량은 20% 수준으로 조절할 필요가 있었다. 또한, 배지 첨가제는 탄산칼슘 처리가 소석회 처리보다 양호하였으며, 무처리구의 경우 갓과 대의 탄력성은 감소하고 경도는 증가되는 경향을 보였다. 따라서, 백령버섯 병재배용 최적배지는 미루나무톱밥+면실피+면실박+밀기울+옥수수분+탄산칼슘이 40:20:20:15:3:2의 혼합 비율로 조성되는 처리구였다.

In this study, we develop and propose damping correction factors for the Korean standard design spectra. The newly proposed Korean standard design spectra has been given only for 5% damping ratio. But in practice, engineers need design spectra for damping values other than 5%. To obtain design spectra for various damping values from the standard spectra, damping correction factors are derived. These factors modify the shape of design spectra in accordance with the damping ratio. Response spectra for various damping values are calculated from the earthquake records that had been used to calculate standard design spectra. They consist of 55 records from 18 earthquakes occurred in overseas intraplate regions and Korea. The regressed spectra for the damping values ranging from 0.5% to 50% are compared with standard spectra at three regions acceleration, velocity and displacement sensitive regions. The regression analysis of these data rendered formula for damping correction factors. Finally, a single formula for damping correction factors is recommended that is valid for both horizontal and vertical design spectra and that is applicable to the entire range of periods. One thing to note that recommended damping correction factors is valid for the design spectrum of the rock grounds because the design spectra was developed based on the earthquake records of the rock ground.

On September 12, 2016, Gyeongju earthquake occurred. Its local magnitude was announced to be ML=5.8 by Korea Meteorological Administration (KMA). Ground motion data recorded at KMA, EMC and KERC stations was obtained from their data bases. From the data, horizontal and vertical response spectra, and V/H ratio were calculated. The horizontal spectrum was defined as geometric mean spectrum, GMRotI50. From the statistical analysis of the geometric mean spectra, a mean plus one standard deviation spectrum in lognormal distribution is obtained. Regression analysis is performed on this curve to determine the shape of spectrum including transition periods. Applying the same procedure, the shape and transition periods of vertical spectrum was obtained. These results were compared with the Korean standard design spectra, which were developed from domestic and overseas intraplate earthquake records. The response spectra of Gyeongju earthquake were found to be almost identical with the newly proposed design spectra. Even the V/H ratios showed good agreement. These results confirmed that the method adopted when developing the standard design spectra were valid and the developed design spectra were reliable.

This study was carried out to establish a cultivation technique for increasing the γ-aminobutyric acid (GABA) content in the fruit body of mushrooms by adding processed by-products. For the oyster mushroom ‘Heucktari’, addition of green tea powder, sea tangle powder, and green tea dregs resulted in very poor primordia formation, fruit body growth, and increased GABA. However, addition of 10% schizandra berry dregs and 1% rice bran to the basal substrate induced 100% and 10% increases, in GABA content in the fruit bodies compared to the control treatment without by-product, respectively. In addition, fruit body growth and primordia formation were greatly increased by these treatments. Therefore, GABA content was increased when the substrate was prepared by mixing an appropriate amount of schizandra berry dregs and rice bran.

The vertical design spectrum for Korea, which is known to belong to an intra-plate region, is developed from the ground motion records of the earthquakes occurred in Korea and overseas intra-plate regions. From the statistical analysis of the vertical response spectra, a mean plus one standard deviation spectrum in lognormal distribution is obtained. Regression analysis is performed on this curve to determine the shape of spectrum including transition periods. The developed design spectrum is valid for the estimation both spectral acceleration and displacement. The ratio of vertical to horizontal response spectrum for each record is calculated. Statistical analysis of the ratios rendered the vertical to horizontal ratio (V/H ratio). Subsequently the ratio between the peak vertical ground acceleration to the horizontal one is obtained.

The design spectrum for Korea, which is known to belong to an intra-plate region, is developed from the ground motion records of the earthquakes occurred in Korea and overseas intra-plate regions. The horizontal spectrum is defined as geometric mean spectrum, GMRotI50. From the statistical analysis of the geometric mean spectra, a mean plus one standard deviation spectrum in lognormal distribution is obtained. Regression analysis is performed on this curve to determine the shape of spectrum including transition periods. The developed design spectrum is valid for the estimation both spectral acceleration and displacement.

이 연구에서는 3축 방향 지반운동이 작용하는 지반-구조물 상호작용계의 비선형 지진응답 해석을 수행한다. 비선형 거동이 예상되는 구조물과 지반의 근역은 비선형 유한요소에 의해 모형을 구성한다. 기하학적 형상과 재료 성질이 균일하고 선형 거동을 가정하는 원역지반은 무한 영역으로의 에너지 방사를 정확히 고려할 수 있는 3차원 perfectly matched discrete layer에 의해 수치 모형을 구성한다. 이와 같은 지반-구조물 상호작용계의 수치모형을 사용하여 3축 방향 지반운동이 작용하는 비선형 지진-구조물 상호작용계의 지진응답해석을 수행한다. 3축 방향 지반운동이 작용하는 경우에는 입력 지반운동의 특성에 따라 시스템의 응답이 우세하게 발현되는 방향이 존재하고 그 수준 또한 정밀한 지진응답해석을 통해 산정하여야 한다. 이 연구의 해석기법은 구조물과 지반의 재료 비선형 거동, 기초와 지반 경계면에서의 경계 비선형 거동 등 다양한 비선형 지반-구조물 상호작용 해석에 확장 적용할 수 있을 것이다.

이 연구에서는 3축 방향 지반운동이 작용하는 지반-구조물 상호작용계의 비선형 지진응답 해석을 수행한다. 비선형 거동 이 예상되는 구조물과 지반의 근역은 비선형 유한요소에 의해 모형을 구성한다. 기하학적 형상과 재료 성질이 균일하고 선 형 거동을 가정하는 원역지반은 무한 영역으로의 에너지 방사를 정확히 고려할 수 있는 3차원 perfectly matched discrete layer에 의해 수치 모형을 구성한다. 이와 같은 지반-구조물 상호작용계의 수치모형을 사용하여 3축 방향 지반운동이 작용 하는 비선형 지진-구조물 상호작용계의 지진응답해석을 수행한다. 3축 방향 지반운동이 작용하는 경우에는 입력 지반운동의 특성에 따라 시스템의 응답이 우세하게 발현되는 방향이 존재하고 그 수준 또한 정밀한 지진응답해석을 통해 산정하여야 한 다. 이 연구의 해석기법은 구조물과 지반의 재료 비선형 거동, 기초와 지반 경계면에서의 경계 비선형 거동 등 다양한 비선 형 지반-구조물 상호작용 해석에 확장 적용할 수 있을 것이다.

본 연구에서는 버섯 수확후배지를 바이오매스로 활용하 고자 수행하였으며, 적정 전처리 조건을 구명한 결과는 다음과 같다. 버섯 수확후 배지의 전처리방법 중 알카리 처리가 리그닌 함량을 효과적으로 경감시키면서, 당전환 율이 우수하였고 큰느타리 수확후 배지가 당전환율 80.7%로 가장 우수하였다. 큰느타리 수확후 배지에 1% NaOH를 이용한 알카리 처리시 전처리 온도별 성분분석 결과 120℃처리시에 glucose 25.3%, xylose 14.8%로 유 리당 함량이 가장 높고, 효소에 의한 당전환율도 66%로 무처리구 28.2%에 비해 2.3배 증가되었다. 촉매제 농도 (NaOH 0.5~2.0%)에 따른 당분석결과 glucose 함량은 촉 매제 농도와 관계가 적었으며, xylose와 arabinose는 촉매제 농도가 높을수록 다소 감소하는 경향이었다. 그러나 당전환율은 NaOH 1% 처리시에 66%로 가장 높았다.

본 연구는 잎새버섯 병 재배시 적합한 배지조성비율을 구명하고자 수행되었다. 배지조성은 참나무톱밥: 옥수수피: 건비지를 건물중량 비 율로 T1처리(67:11:22), T2처리(68:15:17), T3처리(74:14:12)의 3처리를 두고 시험한 결과, 발이율은 T1처리에서 72.6%, T2처리에서 72.1%로 두 처리 간 유의적 차이가 없었으나 T3처리에서는 65.8%로서 다른 두 처리에 비하여 낮았다. 이병률은 T2처리에서 4.1%, T3처리에서 3.7%인데 비하 여 T1처리에서는 9.8%로 가장 높았다. 수확률은 T1처리 에서 64.1%, T3처리에서 63.6%인데 비하여 T2처리에서 는 70.5%로 가장 높았다. 병당 자실체 중량은 T1처리에 서 85.5 g, T2처리에서 83.3 g으로 두 처리 간 유의적 차 이가 없었으나 T3처리에서는 72.4 g으로 다른 두 처리에 비하여 낮았다. 입병 수 10,000병 기준으로 재배 시 수량은 T2처리에서 587 kg으로 T1처리 및 T3처리에 비하여 각각 7% 및 28%가 높았다. 따라서 잎새버섯 병재배 시 적합한 배지조 성비율은 건조중량비율로 참나무톱밥: 옥수수피: 건비지 가 68:15:17인 것으로 나타났다.

느타리버섯에 주로 사용되는 영양원의 수입국별 성분분석 및 재배가능성을 검토하였다. 첫째로 수입국별 영 양원의 성분분석 결과, 중금속 농도는 불검출되거나 미량 조사되었고, 면실박의 총질소함량은 호주산에서 6.22%로 중국산이나 미국산보다 높았으며, 비트펄프는 수입국별 pH 및 화학성이 모두 대등하였다. 둘째로 영 양원별 물리성을 조사한 결과, 압력이 증가할수록 이집트산 비트펄프의 보수력이 높았고, 면실박의 경우 400hpa 및 500hpa에서 미국산의 용적수분함량이 가장 높았으며, 배지재료별 압력에 따른 가비중의 변화는 나 타나지 않았다. 셋째로 재료별로 혼합한 배지의 성분분석은 T2처리구에서 pH 5.51로 가장 높고, 총질소함량 도 2.45로 가장 높았으며, C/N율은 대조구가 28.18로 가장 높았다. 마지막으로 혼합배지에 따른 생육특성 및 수량성 조사 결과 초발이소요일수 및 생육일수는 각각 5일과 4일로 T2보다 짧았고, 수량성 및 생물학적 효율 은 T2를 제외한 처리구에서 모두 대등하였다. 이상의 결과 호주산 면실박을 제외한 재료들을 재배에 사용할 수 있을 것으로 판단되며, 추후 수입국에 따른 계절별 수량성을 검토하여 배지의 안전성을 확보하여야 할 것 으로 판단되었다.

This study was conducted to reduce contamination ratio of oyster mushroom bottle cultivation. The optimalconditions of substrate sterilization for reducing of contamination ratio were at 121oC for 90min. In addition, UV-C irradiation isgood for lower contamination ratio to continue over 6 hours at cooling and inoculation room after sterilization. Thecontamination ratio and density of microorganisms of substrate were showed 0% after sterilization at 121oC for 90min.Trichoderma sp., main pathogen of mushrooms, was detected from substrate after sterilized during 2 or 4 hours at 101oC and 105oC,respectively. The amount of electricity used was the lowest at 121oC for 90min than that of other sterilization conditions. The UV-Cirradiation treatment was used UV-C lamp(40 watts) in the inoculation room(56m3). The density of bacteria did not detected after UV-C irradiation for 6 hours. And the death ratio of bacteria and Trichoderma sp. was 99.9% after UV-C irradiation for 6 hours. However,in the same UV-C irradiation time, the death ration of Cladosporium sp. was 90.9%. Therefore, the death ratio of fungi was lower thanthat of bacteria at the same UV-C irradiation treatment.

The study was conducted to investigate the effects of post-incubation period and temperature treatment conditionsduring incubation on the uniform primordia formation and cultural characteristics of oyster mushroom (Pleurotus ostreatus). Threekinds post-incubation period; 25, 30, 35 days and control were applied for 30 days while two kinds incubation roomtemperature 23oC and 26oC and control were used 20oC. The substrate temperature during pre-incubation was of ‘Suhan No. 1’and ‘Gonji No. 7’. Oyster mushroom varieties tended to increase between 24oC to 26oC at 11 to 15 days after inoculation andthen they were maintained in treatment temperature during post -incubation period. The CO2 occurrence was at the highest at6,500ppm for ‘Suhan No. 1’ and 5,800ppm for ‘Gonji No. 7’ at the time of the highest temperature increase. The ratio of un-uniformal primordia formation and the ratio of non-commercial fruit body were reduced by 40%, 10.5%, respectively comparedto control for ‘Suhan No. 1’ when in the post-incubation temperature was 26oC, and incubated for 10days and 15daystreatment. Also, ‘Gonji No. 7’ was reduced by 19%, 9.5%, respectively when in the post-incubation temperature was 26oC, andincubated for 10 days treatment. Therefore, the higher post-incubation temperature of room and longer post-incubation periodresulted in the higher percentage of primordia formation of two cultivars.

The effect of adding Ca on the microstructural and mechanical properties of as-cast Mg-11Li-3Zn-1Sn(wt%) alloys were investigated. Mg-11Li-3Zn-1Sn-0.4Mn with different Ca additions (0.4, 0.8, 1.2 wt%) were cast under an SF6 and Co2 atmosphere at 720 oC. The cast billets were homogenized at 400 oC for 12h and extruded at 200 oC. The microstructural and mechanical properties were analyzed by OM, XRD, SEM, and tensile tests. The addition of Ca to the Mg-11Li-3Zn-1Sn-0.4Mn alloy resulted in the formation of Ca2Mg6Zn3, MgSnCa intermetallic compound. By increasing Ca addition, the volume fraction and size of Ca2Mg6Zn3 with needle shape were increased. This Ca2Mg6Zn3 intermetallic compound was elongated to the extrusion direction and refined to fine particles due to severe deformation during hot extrusion. The elongation of the 0.8 wt% Ca containing alloy improved remarkably without reduction strength due to the formation of fine grain and Ca2Mg6Zn3 intermetallic compounds by Ca addition. It is probable that fine and homogeneous Ca2Mg6Zn3 intermetallic compounds played a significant role in the increase of mechanical properties.

표고 톱밥배지 재배시 녹색LED 광량에 따른 생육특성 분석 결과 5 umol ·m -2 · s -1에서 3주기 기준 배지당 자실체 의 수량은 239 g으로 형광등 202 g 대비 18% 증수효과가 있었으며, 자실체 폴리페놀 함량은 형광등 107 ppm에 대 비 78.4 ppm으로 27% 정도 낮았지만 에르고스테롤 함량 은 형광등 145 ppm 대비 307 ppm으로 2.1배 높은 함량을 보였다. 전력소모량은 형광등 대비 15.9%의 에너지 절감 율을 보였으며, 전등의 에너지 효율이 77.5%로 가장 컸다.

In this research, magnesium powder was prepared by gas atomizing. Refinement behaviors of magnesium powder produced under different conditions were investigated using a mechanical milling (attrition milling) process. Analyses were performed to assess the characterization and comparison of milled powder with different steel ball sizes and milling times. The powders were analyzed by field emission scanning electron microscope, apparent density and powder fluidity. The particle morphology of the Mg powders changed from spherical particles of feed metals to irregular oval particles, then plate type particles, with an increasing milling time. Because of the HCP structure, deformation occurs due to the existence of the easily breakable C-axis perpendicular to the base, which results in producing plate-type powders. An increase in ball size and the impact energy of the magnesium powder maximizes the effect of refinement. Furthermore, it is possible to improve the apparent density and fluidity according to the smoothness of the surface of the initial powder.

There has been an increasing demand for introducing a base isolation system to secure the seismic safety of a nuclear power plant. However, the design criteria and the safety assessment methodology of a base isolated nuclear facility are still being developed. A performance based design concept for the base isolation system needs to be added to the general seismic design procedures. For the base isolation system, the displacement responses of isolators excited by the extended design basis earthquake are important as well as the design displacement. The possible displacement response by the extended design basis earthquake should be limited less than the failure displacement of the isolator. The failure of isolators were investigated by an experimental test to define the ultimate strain level of rubber bearings. The uncertainty analysis, considering the variations of the mechanical properties of isolators and input ground motions, was performed to estimate the probabilistic distribution of the isolator displacement. The relationship of the displacement response by each ground motion level was compared in view of a period elongation and a reduction of damping. Finally, several examples of isolator parameters are calculated and the considerations for an acceptable isolation design is discussed.