Throughfall (TF)—as a diffusive hydrological water flux—significantly affects ecohydrological and biogeochemical processes within forest ecosystems. Recent investigations have revealed the impact on TF generation processes within unmanaged coniferous plantations of under-canopy structures, particularly those laden with dead branches, as well as upper-canopy structures. However, spatiotemporal variations in TF in such plantations remain unexplored. We investigated these variations in TF in a 33-year-old unmanaged Japanese cypress (Chamaecyparis obtusa Endl.) plantation, laden with dead branches, with a high stand density (SD) of 2,500 stems ha−1. Over a two-year period (May 2017 to May 2019), we conducted weekly TF measurements using 28 manual-type TF collectors. We compared the present TF ratio and canopy water storage capacity (S) with those of previous investigations conducted on Japanese cypress plantations. Moreover, we assessed key indices contributing to spatiotemporal TF variations (canopy cover: CC and distance to the nearest stem: TFd) and potentially influential dead branch indices (number of dead branches: TFdb and vertical spacing length on a stem: TFs) to elucidate TF spatial patterns. The results showed that the TF ratio was notably lower than that in previous studies (n = 13), with SD (r = –0.92, p < 0.001) and S (r = –0.87, p < 0.001) emerging as key influential factors among other stand-structure parameters. Spatial TF patterns exhibited a decreasing trend as the gross rainfall (GR) increased. Temporal stability was not significantly associated with CC (r = 0.120, p = 0.544), TFd (r = 0.068, p = 0.731), TFdb (r = 0.211, p = 0.281), or TFs (r = 0.206, p = 0.292) for any of the TF collectors. These findings underscore the important role of GR in determining the spatial variation of TF. Collectively, our results contribute to an enhanced understanding of TF spatiotemporal heterogeneity in unmanaged Japanese cypress plantations with dead branches.

Natural radionuclides-containing substances (NORM) contain natural radionuclides and cause radiation exposure. In Korea, safety management measures were needed to deal with and dispose of radon mattresses containing monazite in relation to such NORM. However, there is no clear safety management system related to NORM waste in Korea. In order to manage this reasonably and systematically, it is necessary to investigate and analyze standards and management measures related to the treatment and disposal of NORM waste. Therefore, this study investigated and analyzed the exemption and clearance level of NORM waste regulations in international organizations and foreign countries. IAEA GSR Part 3, 2013/59/Euratom, ANSI/HPS N13.53, CRCPD SSRCR Part N, and ARPANSA Publications 15 safety management regulations were analyzed to investigate safety management standards for NORM waste. The exemption and clearance level in international organizations and foreign countries were compared and analyzed based on radioactive concentration and dose. In addition, the management measures proposed for each literature were also investigated. As a result of the analysis, IAEA GSR Part 3 applied 1 mSv as a regulatory exemption level, 1 Bq/g for uranium and thorium series as a clearance level, and 10 Bq/g for K-40 nuclides. The IAEA recommends a differential approach to the potential and scale of exposure. The EU applied 1 Bq/g to uranium and thorium families and 10 Bq/g to K-40 nuclides for both regulatory exemption and clearance levels. The EU recommended that it be managed in proportion to the scale and likelihood of exposure as a result of the action. It is analyzed that this is similar to the IAEA’s management plan. In the United States, there was no single federal government radioactive concentration and dose for NORM management. The management plan differed in management status and level from state to state, and K-40 was excluded from regulation unless it was intentionally enriched. In the case of Australia, the radioactive concentration of uranium and thorium was 1 Bq/g as a standard for regulatory exemption and 1 mSv as a dose. As a management plan, it was suggested to dispose of waste by means of accumulation, dilution/dispersion, and reclamation. It was also suggested that the scale of exposure, like international organizations, take into account the possibility. The results of this study are believed to be used as basic data for presenting domestic NORM waste treatment and disposal methods in the future.

The aim of this study was to investigate the effect of isolated lactic acid bacteria (LAB) on the quality of high moisture rye silage. Rye forage (Secale cereale L.) was harvested at the heading stage (27.3% of dry matter (DM)) and cut into approximately 3-5 cm lengths. Then, the forage divided into 4 treatments with different inoculants: 1) No additives (CON); 2) Lactobacillus brevis strain 100D8 at a 1.2 x 105 colony-forming unit (cfu)/g of fresh forage (LBR); 3) Leuconostoc holzapfelii strain 5H4 at a 1.0 x 105 cfu/g of fresh forage (LHO); and 4) Mixture of LBR and LHO (1:1 ratio) applied at a 1.0 x 105 cfu/g of fresh forage (MIX). About 3 kg of forage from each treatment was ensiled into a 20 L mini-bucket silo in quadruplicate for 100 days. After silo opening, silage was collected for analyses of chemical compositions, in vitro nutrient digestibilities, fermentation characteristics, and microbial enumerations. The CON silage had the highest concentrations of neutral detergent fiber and acid detergent fiber (p = 0.006; p = 0.008) and a lowest in vitro DM digestibility (p < 0.001). The pH was highest in CON silage, while lowest in LBR and MIX silages (p < 0.001). The concentrations of ammonia-N, lactate, and acetate were highest in LBR silage (p = 0.008; p < 0.001; p < 0.001). Propionate and butyrate concentrations were highest in CON silage (p = 0.004; p < 0.001). The LAB and yeast counts were higher in CON and LHO silages compare to LBR and MIX silages (p < 0.001). However, the mold did not detect in all treatments. Therefore, this study could conclude that L. brevis 100D8 and Leu. holzapfelii strain 5H4 can improve the digestibility and anti-fungal activity of high moisture rye silage.

The present study was aimed to estimate the effect of ensiling period and bacterial inoculants on chemical compositions and fermentation characteristics on rye silage harvested at delayed stage. Rye (Secale cereale L.) was harvested after 20 days of heading stage (29.4% dry matter, DM). The harvested rye forage was applied with different inoculants following: applications of distilled water (CON), Lactobacillus brevis (LBB), Leuconostoc holzapfelii (LCH), or mixture of LBB and LCH at 1:1 ratio (MIX). Each forage was ensiled into 20 L mini bucket silo (5 kg) for 50 (E50D) and 100 (E100D) days in triplicates. The E50D silages had higher in vitro digestibilities of DM (IVDMD, p<0.001) and neutral detergent fiber (IVNDFD, p=0.013), and lactate (p=0.009), and acetate (p=0.011) than those of E100D, but lower pH, lactic acid bacteria (LAB), and yeast. By inoculant application, LCH had highest IVDMD and IVNDFD (p<0.05), while MIX had highest lactate and lowest pH (p<0.05). The CON and LCH in E50D had highest LAB and yeast (p<0.05), whereas LBB in E100D had lowest (p<0.05). Therefore, this study concluded that LCH application improved the nutrient digesbility (IVDMD and IVNDFD) of lignified rye silage, and longer ensiling period for 100 days enhanced the fermentation characteristics of silage compared to ensiling for 50 days.

A laser scabbling experiment was performed using a high-power fiber laser to investigate the removal rate of the concrete block and the scabbled depth. Concrete specimens with a 28-day compressive strength of 30 MPa were used in this study. Initially, we conducted the scabbling experiment under a stationary laser beam condition to determine the optimum scan speed. The laser interaction time with the concrete surface varied between 3 s and 40 s. The degree of spalling and vitrification on the surface was primarily dependent on the laser interaction time and beam power. Furthermore, thermal images were captured to investigate the spatial and temporal distribution of temperature during the scabbling process. Based on the experimental results, the scan speed at which the optical head moved over the concrete was set to be 300 mm∙min−1 or 600 mm∙min−1 for the 4.8-kW or 6.8-kW laser beam, respectively. The spalling rates and average depth on the concrete blocks were measured to be 87 cm3∙min−1 or 227 cm3∙min−1 and 6.9 mm or 9.8 mm with the 4.8-kW or 6.8-kW laser beams, respectively.

This study was conducted to estimate the effect of different cutting lengths on fermentation characteristics and aerobic stability of whole crop rice (WCR) silage. The WCR was harvested at the yellow ripe stage (43.7%, DM), and then cut at 5 (R05), 10 (R10), and 20 cm (R20) of the theoretical length of cut with no cut WCR (R60). Each forage was ensiled into 20 L mini bucket silo (5 kg) for 150 days in quadruplicates. The cutting lengths were not affected the chemical compositions of WCR silage (p > 0.05). The pH (p < 0.001) and concentration of ammonia-N (p = 0.022) in WCR silage were increased linearly with the increase of cutting length. The concentration of lactate had quadratic effect (p = 0.007), which was highest in R20 silage (p < 0.05). The concentration of acetate was increased linearly (p = 0.014), but the concentration of butyrate was decreased linearly (p = 0.033). The lactic acid bacteria count was decreased linearly (p = 0.017), and yeast count had quadratic effect (p = 0.009), which was the highest in R20 silage (p < 0.05). Aerobic stability had strong quadratic effect (p < 0.001), which was the highest in R20 silage (p < 0.05). In conclusion, R60 silage had highest pH by a linear increase of ammonia-N concentration and led to low aerobic stability. While R20 silage had the lowest pH by high lactate concentration and led to high aerobic stability.

This study was aimed to determine the effects of hybrid and inoculant on in vitro rumen digestibility and rumen fermentation indices of corn silage. Two corn hybrids(Kwangpyeongok (KW) vs. Pioneer 1543(PI)) were ensiled for 100 days with two inoculants(L. plantarum(LP) vs. L. buchneri(LB)) applied at 1.2 × 105 cfu/g of fresh forage. Silages were incubated in rumen fluid medium at 39℃ for 72 hours. Both of KW and PI had no difference(p>0.05) on in vitro digestibility of dry matter(IVDMD) and neutral detergent fiber(IVNDFD), while application of LB produced higher(p<0.05) IVDMD and IVNDFD than LP. Hybrid and inoculant applications did not affect(p>0.05) total gas volume, ammonia-N, total VFA, and acetate concentrations in the rumen. Applied LB was higher(p<0.05) propionate concentration than LP, while hybrids had no effect(p>0.05). Furthermore, the interaction effect(p<0.05) was occurred in propionate concentration. Butyrate concentration did not affected(p>0.05) by hybrid and inoculant applications, but there was an interaction effect between hybrid and inoculant(p<0.05). Applications of hybrid and inoculant had effects(p<0.05) on iso-butyrate and valerate, without any interaction effects(p>0.05). This study concluded that application of KW and PI has no effects on in vitro rumen digestibility and rumen fermentation indices of corn silage, while application of LB increase the rumen digestibility in both of corn hybrids.

This study was conducted to examine the effect of new inoculants on in vitro digestibility and fermentation characteristics of high moisture rye silage. Rye was harvested at heading stage and divided into 5 treatments, following: No additives(CON); L. plantarum R48-27(NI1); L. buchneri R4-26(NI2); mixture of NI1 and NI2 at 1:1 ratio(MIX); and L. buchneri(LB). The rye forage was ensiled into 10 L bucket silo for 100 days. In vitro digestibility of dry matter and neutral detergent fiber were highest(p<0.05) in NI2 silage. The pH in NI2 and LB silages were lower(p<0.05) than CON silage. Lactate concentration was highest(p<0.05) in NI1 silage. While concentrations of acetate and propionate were highest(p<0.05) in MIX silage. Lactates : acetate ratio was highest(p<0.05) in NI1 silage, but lowest in LB silage. Butyrate concentrations of NI2 and LB silages were lower(p<0.05) than that in CON and NI1 silages. Lactic acid bacteria (LAB) count in all inoculated silages was higher(p<0.05) than that in CON silage, while yeast count in LB silage was lower than in CON, NI1, and MIX silages. In conclusion, application of NI2 inoculant could improve potentially fermentation quality and digestibility of high moisture rye silage.

This study was carried out to estimate the effect of selected inoculants on chemical compositions and fermentation characteristics of rye silage. Rye was harvested at dough stage and divided into 5 treatments, following: No additives (CON); L. plantarum R48-27 (LP27); L. buchneri R4-26 (LB26); Mixture of LP27 and LB26 at 1:1 ratio (MIX); and L. buchneri (LB). The rye forage was ensiled into 10 L bucket silo for 100 days. The contents of NDF and ADF were lowest (P<0.05) in LB26. The pH in LB26, MIX, and LB were lower (P<0.05) than CON and LP27. Lactate content in LB was higher (P<0.05) than the others, while acetate content in LB26 and LB were higher (P<0.05) than that in CON and LP27. Lactate to acetate ratio was highest (P<0.05) in LB, but lowest in LB26. Lactic acid bacteria (LAB) count in LB was higher (P<0.05) than that in CON, while yeast count in CON was lower than in all silages applied inoculants. In conclusion, silages inoculated with LB26 could improve potentially the aerobic stability caused by increases of acetate and propionate concentrations.

본 연구에서는 비슬산 이중편파 Radar 자료와, GPM 위성자료 및 21개 (Korea Meteorological Administration, KMA) 지상강우자료를 활용하여 분포형 강우-유출 모형(KIneMatic wave STOrm Runoff Model2, KIMSTORM2)을 이용해 남강댐 유역(2,293 km2)을 대상으로 유출해석을 수행 하였다. 모형의 유출 해석은 2016년 10월 5일 02:00∼09:00 총 8시간 동안 최대강우강도 33 mm/hr, 유역평균 총 강우량 82 mm이 발생한 태풍 차 바(CHABA)를 대상으로 하였으며, Radar 및 GPM 자료와 조건부합성(Conditional Merging, CM) 기법을 적용한 Radar (CM-corrected Radar) 및 GPM (CM-corrected GPM) 자료를 각각 활용하여 결과를 비교하였다. 이 때, 공간 강우자료에 유출 검보정은 남강댐 유역 내 3개의 수위관측 지점(산청, 창촌, 남강댐)을 대상으로 실시하였으며, 모형의 매개변수 초기토양수분함량, 지표와 하천의 Manning 조도계수를 이용하여 검보정하였다. 유출 결과는 결정계수(Determination coefficient, R2), Nash-Sutcliffe의 모형효율계수(NSE) 및 유출용적지수(Volume Conservation Index, VCI)를 산정하였다. 그 결과 CM-corrected Radar, GPM 자료가 평균 R2는 0.96, NSE의 경우 0.96, 유출용적지수(VCI)는 1.03으로 가장 우수한 결과를 나타내었다. 최종적으로 CM 기법을 이용한 보정된 공간분포자료는 기존의 자료에 비해 시공간적으로 정확한 홍수 예측에 사용 될 것으로 판단된다.

본 연구에서는 보령댐 유역(163.6 km2)을 대상으로 SWAT (Soil and Water Assessment Tool) 모델, GCM (General Circulation Model) 기 후변화 시나리오와 다중회귀분석으로 산정한 미래 방류량을 활용하여 극한 기후변화 사상이 반영된 보령댐의 물부족을 평가하였다. 유역의 물수지 분석을 위해 보령댐 유역을 대상으로 기상자료, 보령댐 운영자료를 수집하였으며, SWAT 모형의 신뢰성 있는 유출량 보정을 위해 보령댐의 실 측 방류량을 이용하여 댐 운영모의를 고려하였고 유입량 및 방류량 자료를 활용하여 모형의 보정(2007~2010)과 검증(2010~2016)을 실시하였다. 기후변화를 반영하기 위해 APCC의 26개 CMIP5 GCM 자료 중 RCP (Representative Concentration Pathway)4.5와 RCP 8.5 시나리오를 SPI와 극한 가뭄지수로 분석하여 RCP 8.5 BCC-CSM1-1-M을 극한 가뭄 시나리오로 선정하였다. 2005년부터 2016년까지의 일별 관측자료로 다중회귀분석하여 월별 방류량 추정식을 만들었고, 1월부터 12월까지 각 식들의 결정계수 R2는 0.57 이상으로 나타났다. 선정된 극한 가뭄 시나리오 기상자료를 방류량 추정식에 대입하여 미래기간 일별 방류량을 구축하였다. SWAT 수문평가 결과, S3 (2037~2046) 기간 봄철 저수량이 34.0% 감소하는 것으로 분석되었다. Runs 이론을 바탕으로 물부족의 심도를 구한 다음 재현기간에 따른 빈도해석을 하였다. 5~10년 빈도의 심 도로 발생하는 물부족이 미래기간에 발생하는 빈도로 보령댐의 물부족을 평가하였다. 물부족 평가 결과, S3 (2037~2046) 기간에서 5~10년 빈도의 심도를 가지는 물부족이 기준기간(2007~2016) 보다 2회 더 발생하였으며 S3 (2037~2046)에 물부족 계획 수립이 필요하다고 판단하였다.

본 연구의 목적은 기상자료(강수량, 최고기온, 최저기온, 평균기온, 평균풍속) 기반의 다중선형 회귀모형을 개발하여 농업용저수지 저수율을 예측 하는 것이다. 나이브 베이즈 분류를 활용하여 전국 1,559개의 저수지를 지리형태학적 제원(유효저수량, 수혜면적, 유역면적, 위도, 경도 및 한발빈도)을 기준으로 30개 군집으로 분류하였다. 각 군집별로, 기상청 기상자료와 한국농어촌공사 저수지 저수율의 13년(2002~2014) 자료를 활용하여 월별 회귀모형을 유도하였다. 저수율의 회귀모형은 결정계수(R2)가 0.76, Nash-Sutcliffe efficiency (NSE)가 0.73, 평균제곱근오차가 8.33%로 나타났다. 회귀모형은 2년(2015~2016) 기간의 기상청 3개월 기상전망자료인 GloSea5 (GS5)를 사용하여 평가되었다. 현재저수율과 평년저수율에 의해 산정되는 저수지 가뭄지수(Reservoir Drought Index, RDI)에 의한 ROC (Receiver Operating Characteristics) 분석의 적중률은 관측값을 이용한 회귀식에서 0.80과 GS5를 이용한 회귀식에서 0.73으로 나타났다. 본 연구의 결과를 이용해 미래 저수율을 전망하여 안정적인 미래 농업용수 공급에 대한 의사결정 자료로 사용할 수 있을 것이다.

세기변조방사선치료와 입체적세기조절회전치료 시 조사체적과 선량 퍼짐 현상을 줄이기 위한 방법으로 조사 각도를 제한하는 부분 각도에 의한 회전치료 기능을 적용하여 표적체적과 주변 정상장기의 선량에 대해 입체조형방사선치료와 비교 분석하였다. 치료계획에 따른 표적체적의 선량분포는 통계적으로 유의한 차이를 확인할 수 없었으며, 폐의 5 Gy(V5) 체적에서 입체조형방사선치료 56.53%, 세기변조방사선치료 52.03%, 입체적세기조절회전치료 47.84%를 나타내어 유의한 차이를 나타내었다(CRT-IMRT p=0.035, CRT-VMAT p<0.001, IMRT-VMAT p<0.001). 10 Gy 체적(V10)에서는 입체조형방사선치료 35.12%, 세기변조방사선치료 34.04%, 입체적세기조절회전치료 33.28%를 보여, 입체조형방사선치료와 세기변조방사선치료(p=0.018), 입체적세기 조절회전치료(p=0.035)에서 유의한 차이를 나타내었으나 20 Gy 체적(V20)에서는 유의한 선량 차이를 확인 할 수 없었다. 심장의 평균선량과 20 Gy 체적은 치료계획에 따라 유의한 차이를 확인할 수 없었으나, 30, 40 Gy 체적은 입체적세기조절회전치료에서 37.16%, 22.46%를 나타내어 입체조형방사선치료와 비교에서 유의한 차이(p=0.028)를 보였다. 이와 같이 조사체적 감소에 따른 폐의 저 선량 체적(V5, V10)의 감소를 확인할 수 있었으며, 세기변조방사선치료와 입체적세기조절회전치료 시 조사 각도를 일부 제한함으로써 표적체적의 선량분포는 동일하게 유지함과 동시에 조사체적을 줄일 수 있었다. 이로 인해 폐의 선량 퍼짐 현상의 감소로부터 폐의 독성을 낮추는데 기여할 수 있을 것으로 사료된다.