The recent release of contaminated water from the Fukushima Daiichi Nuclear Power Plant highlights the need for accurate tritium measurement, particularly near the minimum detectable activity (MDA) of 5 Bq·L−1 set by South Korea’s Nuclear Safety and Security Commission. This study aims to improve low-level tritium measurement accuracy by optimizing the region of interest (ROI) for quench curve determination. These adjustments are crucial for separating tritium signals from background noise. Quench standards were prepared and measured using a liquid scintillation counter (LSC). Three ROIs were analyzed to assess the impact of channel selection on measurement precision: A 20-148 channel range optimized via figure of merit (FOM) analysis, a 20-250 channel range covering tritium’s full beta spectrum, and a broad 1-1024 channel range. Quench curves were obtained by fitting the counting efficiency of each ROI to the quench standards. Tritium samples with six different activity levels were prepared, and their radioactivity was calculated using the quench curves. Selecting appropriate ROIs for quench curve determination is critical for measuring low-concentration tritium accurately. This approach reduces uncertainty and emphasizes reliable methods to improve the precision and consistency of tritium measurements.
곤충호텔은 곤충이 서식할 수 있도록 인위적으로 만든 구조 물로서 정원이나 텃밭 등 다양한 곳에서 활용되고 있다. 하지만 식생유형, 재료, 설치 방식 등에 따른 곤충 유입 효과에 대한 검증은 부족하며, 국가 또는 지역에 따른 곤충의 종류와 생육환 경이 다름에도 불구하고 곤충호텔에 대한 국내 연구는 전무한 실정이다. 따라서 본 연구에서는 국립수목원을 대상으로 구체적 인 식생유형 및 재료에 따른 유입 곤충 특성을 확인하고, 국내 실정에 맞는 효과적인 곤충호텔 설치 및 관리방안에 대한 기준 을 제시하고자 하였다. 조사구는 세 가지 식생유형(초지, 침엽수 림, 활엽수림)으로 구분하였으며, 각 식생의 조사구에 두 가지 재료(참나무, 잣나무)를 활용한 곤충호텔을 설치하였다. 조사는 2년동안(2022~2023) 진행되었으며, 매년 4~9월까지 주 1회 씩(총 48회) 곤충호텔의 유입 곤충을 직접 채집하였다. 곤충호 텔에서 채집된 곤충은 총 9목 46과 129종 3,057개체로, 2022 년에는 7목 34과 85종 1,750개체, 2023년에는 8목 35과 77종 1,307개체가 출현하였다. 연도별로 비교하면 1차년도에 유입 된 곤충의 개체수가 2차년도 보다 약 1.3배 많았고, 재료의 부식 에 따른 곤충의 구성도 달라졌다. 식생유형에 따라 구분하면 기간에 상관없이 활엽수림에서 유입 곤충이 가장 많았고, 침엽 수림에서 가장 적었다. 또한 재료에 따른 구분에서는 참나무가 잣나무보다 유입 곤충이 많았다. 참나무의 경우 유입 곤충의 연도별 차이가 적은 반면, 잣나무는 1년차에 비해 2년차에 약 2.3배 줄었다. 상관분석과 계층적 군집분석을 통한 곤충의 유입 특성은 식생유형보다는 재료의 영향이 큰 것으로 확인되었고, 식생유형만 비교했을 경우 초지에 비해 활엽수림과 침엽수림의 유사성이 높았다. 결론적으로 생물 다양성 증진을 목적으로 곤 충호텔을 설치하고자 한다면 초지나 활엽수림에 참나무 재료를 사용하는 것이 유리하며, 잣나무 재료를 이용한다면 1년 주기로 재료 교체가 필요할 것으로 판단된다. 하지만 특정 재료를 선호 하는 곤충의 기주특이성이 확인되었기 때문에 다양한 종류의 재료를 같이 사용하는 것도 하나의 방법이라고 사료된다. 향후 이를 기반으로 전시원에서 실질적으로 활용할 수 있는 곤충호텔 모델 개발로 확대해 나갈 예정이다.
국립수목원 전시원의 지속가능하고 친환경적인 관리를 위하 여 유기물 멀칭재 처리에 대한 잡초 억제 효과를 조사하였다. 대표적 잡초인 쑥군락과 바랭이군락을 대상으로 고정방형구 (1×1㎡)를 3반복 설치하였다. 처리구의 유기물 멀칭재는 5가지 재료로 활엽수 우드칩, 침엽수 바크, 갈참나무 낙엽, 메타세쿼이 아 낙엽, 칠엽수 과피를 사용하였다. 멀칭재 중에서 갈참나무 낙엽, 활엽수 우드칩, 칠엽수 과피가 비교적 잡초 억제 효과가 높은 것으로 나타났다. 갈참나무 낙엽은 지중 온도를 낮게 유지 하는 효과가 상대적으로 좋았기 때문에 토양의 보습 효과가 뛰 어날 것으로 판단된다. 유기물 멀칭재 처리는 일년생식물의 발 생은 억제하고, 지중식물 및 반지중식물의 생육에 도움을 주는 효과가 있었다. 멀칭재의 무게보다 재료에 의한 빛 차단 면적이 잡초를 억제하는 주된 요인이었다. 본 연구 결과는 국립수목원 전시원에서 발생하는 부산물을 활용한 친환경적 관리 방안 수립 에 활용될 것이며, 향후 잡초의 발생 시기에 따른 멀칭 시기 및 유기물 멀칭재의 유지 관리에 대한 추가적인 연구가 필요하다.
Following the previous study, which investigated the pharmacological properties of the Technekitty injection (Tc-99m), the toxicity of a single intravenous administration of the Technekitty injection (Tc-99m) and the side effects that may occur at the diagnostic dose were confirmed. The Technekitty injection (Tc-99m) was administered intravenously once at a dose of 0, 0.67, 2.0, and 6.0 mCi/kg to 5 male and female rats per group. Mortality, general symptom observation, and weight measurement were performed for 2 weeks, followed by observation of autopsy findings. There were no deaths, and no statistically significant weight change was observed. No abnormal systemic signs related to the Technekitty injection (Tc-99m) were observed. These results confirmed that Technekitty injection (Tc-99m) can be safely administered intravenously at doses up to 6.0 mCi/kg. Additionally, technetium-99m at an average dose of 2 mCi (74 MBq) has been verified as a diagnostic dose without adverse effects, allowing the Technekitty injection (Tc-99m) to be used safely without side effects at this dosage. This study demonstrates that the Technekitty injection (Tc-99m) has a wide safety margin, supporting its potential for clinical application. Moreover, these findings align with the nonclinical safety standards for radiopharmaceuticals, reinforcing its utility in veterinary medicine. The Technekitty injection (Tc-99m) is expected to be applicable for clinical diagnosis as a veterinary drug in Korea.
Thyroid scanning using technetium-99m (99mTc) is the gold standard for diagnosing feline hyperthyroidism. In cats with an overactive thyroid, a thyroid scan is the most appropriate imaging technique to detect and localize any hyperfunctional adenomatous thyroid tissue. In this study, the pharmacological properties of the Technekitty injection (Tc-99m), developed as a diagnostic agent for feline hyperthyroidism using 99mTc as an active ingredient, were tested in FRTL-5 thyroid follicular cell line and ICR mice. The percentage of cell uptake of the Tc-99m in FRTL-5 thyroid cells was 0.182 ± 0.018%, which was about 6 times higher compared to Clone 9 hepatocytes. This uptake decreased by 38.2% due to competitive inhibition by iodine (sodium iodide). In tissue distribution tests by using ICR mice, the highest distribution was observed in the liver, kidneys, spleen, lungs, and femur at 0.083 hours after administration, and this distribution decreased as the compound was excreted through the kidneys, the primary excretory organ. Maximum distribution was confirmed at 1 hour in the small intestine, 6 hours in the large intestine, and 2 hours in the thyroid gland. Additionally, the total amount excreted through urine and feces over 48 hours (2 days) was 78.80% of the injected dose, with 37.70% (47.84% of the total excretion) excreted through urine and 41.10% (52.16% of the total excretion) through feces. In conclusion, the Tc-99m has the same mechanism of action, potency, absorption, distribution, metabolism, and excretion characteristics as 99mTc used for feline hyperthyroidism in the United States, Europe, and other countries, because the Technekitty injection (Tc-99m) contains 99mTc as its sole active ingredient. Based on these results, the Technekitty injection (Tc-99m) is expected to be safely used in the clinical diagnosis of feline hyperthyroidism.
Si-based anodes are promising alternatives to graphite owing to their high capacities. However, their practical application is hindered by severe volume expansion during cycling. Herein, we propose employing a carbon support to address this challenge and utilize Si-based anode materials for lithium-ion batteries (LIBs). Specifically, carbon supports with various pore structures were prepared through KOH and NaOH activation of the pitch. In addition, Si was deposited into the carbon support pores via SiH4 chemical vapor deposition (CVD), and to enhance the conductivity and mechanical stability, a carbon coating was applied via CH4 CVD. The electrochemical performance of the C/Si/C composites was assessed, providing insights into their capacity retention rates, cycling stability, rate capability, and lithium-ion diffusion coefficients. Notably, the macrostructure of the carbon support differed significantly depending on the activation agent used. More importantly, the macrostructure of the carbon support significantly affected the Si deposition behavior and enhanced the stability by mitigating the volume expansion of the Si particles. This study elucidated the crucial role of the macrostructure of carbon supports in optimizing Si-based anode materials for LIBs, providing valuable guidance for the design and development of high-performance energy-storage systems.
Mesocrystals are macroscopic structures formed by the assembly of nanoparticles that possess distinct surface structures and collective properties when compared to traditional crystalline materials. Various growth mechanisms and their unique features have promise as material design tools for diverse potential applications. This paper presents a straightforward method for metal–organic coordination-based mesocrystals using nickel ions and terephthalic acid. The coordinative compound between Ni2+ and terephthalic acid drives the particle-mediated growth mechanism, resulting in the mesocrystal formation through a mesoscale assembly. Subsequent carbonization converts mesocrystals to multidirectional interconnected graphite nanospheres along the macroscopic framework while preserving the original structure of the Ni-terephthalic acid mesocrystal. Comprehensive investigations demonstrate that multi-oriented edge sites and high crystallinity with larger interlayer spacing facilitate lithium ion transport and continuous intercalation. The resulting graphitic superparticle electrodes show superior rate capability (128.6 mAh g− 1 at 5 A g− 1) and stable cycle stability (0.052% of capacity decay per cycle), certifying it as an advanced anode material for lithium-ion batteries.
Efforts have been extensively undertaken to tackle overheating problems in advanced electronic devices characterized by high performance and integration levels. Thermal interface materials (TIMs) play a crucial role in connecting heat sources to heat sinks, facilitating efficient heat dissipation and thermal management. On the other hand, increasing the content of TIMs for high thermal conductivity often poses challenges such as poor dispersion and undesired heat flow pathways. This study aims to enhance the through-plane heat dissipation via the magnetic alignment of a hybrid filler system consisting of exfoliated graphite (EG) and boron nitride (BN). The EG acts as a distributed scaffold in the polymer matrix, while the BN component of the hybrid offers high thermal conductivity. Moreover, the magnetic alignment technique promotes unidirectional heat transfer pathways. The hybrid exhibited an impressive thermal conductivity of 1.44 W m− 1 K− 1 at filler contents of 30 wt. %, offering improved thermal management for advanced electronic devices.
본 연구는 국립수목원 내 전문전시원에 발생한 이입식물을 대상으로 2015년부터 2023년까지 이입식물 분포조사를 시행 하였다. 그 결과 자생식물 299종, 귀화식물 49종, 재배식물 13 종 총 63과 214속 361종이 조사되었다. 국화과가 63종으로 가장 많았고, 벼과, 사초과 순으로 발생하였다. 이입식물의 이입 경로를 분석하기 위하여 광릉숲에 분포하는 식물상과 비교 분석 한 결과 309종이 광릉숲에 분포하는 식물로 확인되었으며, 전 문전시원 내 식재 식물이 확산된 경우가 17종으로 조사되었다. 조사된 귀화식물 49종을 원산지별로 구분하면 유럽과 북아메리카가 69.4%, 이입 시기별 1기와 3기의 비율이 90%를 차지하였 다. 귀화식물의 귀화도 분포 등급을 적용한 결과 4등급 이상이 면서 이입 시기가 3기인 식물 9종은 빠르게 확산할 우려가 큰 식물이므로 지속적인 모니터링이 필요하다. 국립수목원에 어느 정도 귀화식물이 분포하는지를 가늠하는 도시화지수를 산출한 결과 15.0%로 나타났으며, 환경부 지정 생태계교란 야생식물 중 돼지풀, 단풍잎돼지풀, 애기수영, 미국쑥부쟁이가 출현하였 다. 이입식물은 자생식물군락과 전문전시원 내 관람로에 침입하 여 세력권을 확장하고 우점하는 경향이 있어 각각의 생태적 특 성을 고려한 제거 방법이 필요하다.
Background: The Hanwoo industry must develop technologies that can increase the production of preferred cuts to match changing consumer trends. In this study, we aimed to estimate the genetic parameters for carcass traits (carcass weight, eye muscle area, back fat thickness, and intramuscular fat) and primal cut traits (tenderloin, loin, strip loin, neck, clod, top round, bottom round, brisket, shank, and rib) in a Hanwoo population to obtain basic data for improving primal cut productivity. Methods: Data from 1,905 Hanwoo steers, including carcass traits and primal cut weights, were collected. Genetic parameters were estimated using REMLF90 in a multi-trait analysis. Results: High heritability was found for carcass weight (0.52) and strip loin yield (0.63). Genetic correlations between carcass weight and primal cut weights ranged from 0.52 to 0.93. Conclusions: This study demonstrates the significant potential for genetic improvement in Hanwoo cattle through selective breeding, particularly for traits with high heritability and genetic correlations. These findings provide crucial insights into optimizing breeding programs to improve Hanwoo cattle production efficiency.