With the increasing demand for flexible electronic devices, smaller and lighter flexible supercapacitors have gained significant research attention. Among the various materials, self-supporting reduced graphene oxide (rGO) paper has emerged as one of the most promising electrode materials for supercapacitors due to its low cost, high chemical/thermal stability, and excellent electrical conductivity. Nevertheless, a major drawback of rGO paper is the limited ion diffusion between stacked rGO layers, hindering the effective formation of electrochemical double-layer at the electrode/electrolyte interface. In this study, we prepared the rGO paper derived from ball-milled followed-by water oxidation process for reducing the sheet size. The smaller-sized rGO sheets facilitated ion transport between graphene layers, promoting efficient electric double-layer formation. Moreover, the increased presence of edge planes in ball-milled rGO sheets achieved high capacitance, further enhancing the performance of rGO as an electrode material. Notably, the 2-BMOX rGO paper obtained from ball-milling and wet-oxidized graphite exhibited a capacitance of 117.9 F/g in cyclic voltammetry (CV) and 128.6 F/g in galvanostatic charge–discharge (GCD) tests, approximately twice that of conventional rGO. Additionally, the capacitance retained 91% of its initial performance after 2,000 cycles, indicating excellent cycling stability.
비모란 선인장 ‘Ahwang’ 품종이 2016년에 국립원예특작과 학원에서 육성되었다. 증식력이 우수한 밝은 황색 ‘Ahwang’ 품종 육성을 위해서, 황색 ‘Hwangun’품종을 모본으로, 황색 ‘0930001’ 계통을 부본으로 하여 2012년 6월 25일에 교배하였다. 어린 비모란 선인장을 2014년 이전에 삼각주에 2번 접목하여 계통을 양성하였으며 2014년부터 2016년까지 총 3회에 걸쳐 생육특성을 조사하였다. ‘Ahwang’ 품종의 모구는 편원형 모양에 황색 구색(Y9A)이다. 모구는 평균 8.6개의 능(rip)과 2.7mm의 짧은 직립형 회색 가시를 가지고 있고 혹(tubercle)이 돌출된 형태를 띠고 있다. 10개월 재배 후 ‘Ahwang’ 품종의 구직경은 44.5mm였으며 자구는 평균 26.9개가 생성되었다. ‘Ahwang’ 품종은 모구 능마다 황색의 자구가 3-4개가 착생되었다. 2016년 육성계통 평가회에서 ‘Ahwang’ 품종은 기호도 점수 3.9을 받았다. 이 품종은 2018년 5월 16일 국립종자원에 등록되었으며 식물신품종보호법에 의해 품종보호(등록번호 7193)를 받게 되었다.
HPT research studies and practices have been largely conducted in the corporate setting, leaving education as a neglected context despite its strong emphasis on performance in teaching, learning, and school management. In this study, we examine the application of the HPT standards and their effects on Korean teachers’ performance goal achievement for students. With HPT standards, we also investigate the interaction effect of teacher tenure on the relationship among HPT standards and goal achievement. The Hayes Process Model is adopted to examine the second-stage moderated mediation model. The findings support that the principle standards positively mediate the effect of the process standards on the teachers’ goal achievement, and teacher tenure moderates the HPT standards’ effects on goal achievement. The practical and theoretical implications of the results are discussed, as well as limitations and future research suggestions
DNA methylation is the most common and well-characterized epigenetic change in human cancer. Recently, the association between GATA-binding protein 5 (GATA5) methylation and carcinogenesis of various types of tumors was investigated. The aim of the present study was to evaluate the effect of GATA5 methylation status on clinicopathological features and prognosis in primary non-muscle invasive bladder cancer (NMIBC) patients with a long-term follow-up period. The GATA5 methylation status was determined for 171 human bladder specimens (eight normal controls [NCs] and 163 primary NMIBC patients) using quantitative pyrosequencing analysis. The primary NMIBC tissues were obtained from patients who underwent transurethral resection (TUR) for histologically diagnosed transitional cell carcinomas between 1995 and 2012 at Chungbuk National University Hospital. GATA5 methylation was significantly higher in NMIBC patients than in NCs and was significantly associated with higher grade and more advanced stage of cancer. Kaplan-Meier estimates showed significant differences in tumor recurrence and progression according to GATA5 methylation status (each p<0.05). Our results show that increased methylation of GATA5 was significantly associated with not only aggressive characteristics but also poor prognosis in primary NMIBC patients. Alteration of GATA5 methylation might be used as a biomarker for prognosis of NMIBC patients. However, prospective and functional investigations are necessary to clarify the role of GATA5 methylation in future clinical management of patients with NMIBC.
지진하중에 대한 구조물의 동적 거동과 내진성능을 평가하기 위하여 유사동적실험기법이 흔히 사용되고 있으나, 실험장비의 제약과 구조물의 규모 등으로 대부분 축소모형실험에 의존하고 있다. 그러나 일반적인 상사법칙은 탄성범위에서 유도된 것으로 지진거동과 같은 비탄성 거동을 예측하는 경우에는 한계가 있기 때문에 축소모형의 실험결과를 원형 구조물에 직접 적용하는 것은 많은 주의가 필요하다. 본 연구에서는 원형구조물과 축소모형에 대한 철골모형을 실험 대상으로 하여 실제 축소모형 실험결과로부터 원형구조물의 거동을 예측하는 경우의 문제점을 확인하고, 그 해결방법을 모색하고자 한다. 실제로 축소모형실험에서는 원형구조물의 경계조건을 정확히 재현하기 어려우며, 축소모형의 제작과정과 실험과정에서의 모든 오차가 강성의 변화로 반영되어 나타난다. 따라서 본 연구에서는 기하학적 상사율과 축소모형의 변화된 강성비를 함께 고려한 수정된 상사법칙을 제안하였으며, 수정된 상사법칙이 적용된 축소모형에 대하여 유사동적실험을 수행하여 지진응답결과를 원형구조물의 결과와 비교하였다. 축소모형에 대한 유사동적실험결과로부터 제안된 상사법칙을 적용함으로써 원형구조물의 지진응답 재현이 효과적임을 입증하였다.
This study presents a rapid and sequential radiochemical separation method for Pu and Am isotopes in radioactive waste samples from the nuclear power plant with anion exchange resin and TRU resin. After radionuclides were leached from the radioactive waste samples with concentrated HCl and HNO3, the sample was allowed to evaporate to dryness after filtering the leaching solution with 0.45 micron filter. The Pu isotopes were separated in HNO3 medium with anion exchange resin. For leaching solution passed through anion exchange column, the Am isotopes were separated with TRU resin. The purified Pu and Am isotopes were measured by alpha spectrometer, respectively, after micro-precipitation of neodymium. The sequential radiochemical separation of Pu and Am isotopes in radioactive waste samples using anion exchange resin and TRU resin was validated with ICP-MS system.