댐 부유물 톱밥과 하수슬러지를 활용한 부숙질 비료가 수목생장 및 토양특성에 미치는 영향

류지훈(Ji Hoon Ryu),박관수(Gwan Soo Park),이상진(Sang Jin Lee),이항구(Hang Goo Lee),박범환(Bum Hwan Park),이종진(Jong Jin Lee) 충남대학교 농업과학연구소 2010 농업과학연구 Vol.37 No.2

This study was conducted to investigate the effect of fertilizer composted of dam suspended particle sawdust and sewage sludge to soil properties and seedling growth. The Betula platyphylla var japonica, Zelkova serrata and Chamaecyparis obtusa were used for this study. The soil organic matter, total nitrogen, phosphorous, exchangeable calcium, magnesium, and potassium were increased with fertilizer treatment. Heavy metal concentration in soil was increased with fertilizer treatment, but the level was very low. With fertilizer treatment, growth, photosynthetic capacity, and chlorophyll concentration of seedling were improved.

수분이 지연제에 미치는 영향을 이해하기 위한 분광학적 해석

류지훈(Ji Hoon Ryu),양준호(Jun Ho Yang),여재익(Jack J Yoh) 한국추진공학회 2019 한국추진공학회 학술대회논문집 Vol.2019 No.5

질식 고주파 자궁근종용해술을 이용한 자궁평활근종 및 자궁선근증의 보존적 치료에 대한 효과의 비교분석

류지훈 ( Ji Hoon Ryu ),김기환 ( Ki Hwan Kim ),박준숙 ( Jun Suk Park ),양윤석 ( Yoon Seok Yang ),오관영 ( Kwan Young Oh ),노정훈 ( Jeong Hoon Rho ),이병관 ( Byung Kwan Lee ),송영래 ( Young Rae Song ),황인택 ( In Taek Hwang ) 대한산부인과학회 2008 Obstetrics & Gynecology Science Vol.51 No.1

목적: 자궁평활근종 환자들과 임상증상 및 치료가 비슷한 자궁선근증 환자들의 질식 고주파 자궁근종용해술의 임상효과에 대하여 비교하고자 한다. 연구 대상 및 방법: 2005년 5월부터 2006년 5월까지 본원에서 자궁평활근종과 자궁선근증으로 진단 받은 총 108명을 대상으로 질식 고주파 자궁근종용해술을 시행하였다. 시술 전, 후 초음파를 이용하여 평활근종과 선근증의 크기, 개수, 위치 그리고 부피를 측정하였으며, 시술 후 매 방문마다 증상과 삶의 질에 대한 질문표를 사용해 호전 유무를 추적, 관찰하였다. 통계학적 유의성을 알아보기 위해 Wilcoxon signed rank test (SPSS 13.0)를 이용하였고 P값이 0.05 미만인 경우를 의미있다고 판정하였다. 결과: 질식 고주파 근종용해술을 시행 받은 76명의 평활근종 환자에서 평균 최대직경은 시술 후 1개월, 3개월, 6개월, 9개월에 각각 14.6%, 23.3%, 30.6%, 33.6%의 감소율과, 평균 부피는 각각 35.7%, 53.3%, 67.3%, 72.2%의 감소를 보였다. 또한 32명의 선근증 환자에서도 평균 최대직경은 시술 후 각각 8.9%, 13.6%, 14.6%, 11.9%의 감소율과, 평균 부피는 각각 22.6%, 30.0%, 32.3%, 28.4%의 감소를 보였다. 평활근종의 경우 증상의 중증도 (Symptom score)는 시술 전, 시술 후 각각 62.3, 52.2, 40.6, 32.6, 28.6이었고, 삶의 질 (QOL score)은 각각 68.9, 78.1, 82.9, 85.7, 87.3이었다. 선근증의 경우 증상의 중증도는 각각 77.7, 37.6, 30.6, 54.4, 67.5였고, 삶의 질은 각각 48.1, 76.5, 85.5, 66.5, 55.1이었다. 결론: 질식 고주파 자궁근종용해술은 자궁을 보존할 수 있고 비침습적이며, 근종의 크기 및 증상의 감소에 효과가 있고 바로 일상생활로의 복귀가 가능하다는 장점이 있다. 그러나 자궁선근증은 시술 후 약 6-9개월 이후 증상이 재발되는 경향을 보여 추가적인 연구 및 추적관찰을 통해 엄격한 적용기준이 마련되어야 할 것이다. Objective: To compare the clinical effectiveness of transvaginal radiofrequency myolysis of the patients with leiomyomas and the patients with adenomyosis which have similar clinical symptoms. Methods: From May 2005 to May 2006 at Eulji university hospital, 108 women who were diagnosed of leiomyoma and adenomyosis had undergone transvaginal radiofrequency myolysis. Before and after the procedure size, number of uterine myomas, location and the volume of the leiomyomas and adenomyosis were measured by ultrasound. And on every visit after the procedure improvement of the symptom was checked by questionnaire of the symptom and life quality. Using Wilcoxon signed ranked test, the statistical significance was proved and the P value lower than 0.05 was judged to be significant. Results: 76 women with leiomyoma who had undergone transvaginal radiofrequency myolysis, were followed up 1 month, 3 months, 6 months and 9 months after the procedure. The average maximal diameter of the myoma was decreased by 14.6%, 23.3%, 30.6%, 33.6% respectively, and the average volume was decreased by 35.7%, 53.3%, 67.3%, 72.2% respectively. 32 women with adenomyosis who had undergone transvaginal radiofrequency myolysis were followed up, at the same period after the procedure. The average maximal diameter of the adenomyosis was decreased by 8.9%, 13.6%, 14.6%, 11.9% respectively, and the average volume was decreased by 22.6%, 30.0%, 32.3%, 28.4% respectively. Before and after the procedure the symptom score was 62.3, 52.2, 40.6, 32.6, 28.6 respectively, and the quality of life score was 68.9, 78.1, 82.9, 85.7, 87.3 respectively in the leiomyoma group. In the adenomyosis group, before and after the procedure the symptom score was 77.7, 37.6, 30.6, 54.4, 67.5 respectively, and the quality of life score was 48.1, 76.5, 85.5, 66.5, 55.1 respectively. Conclusion: Transvaginal radiofrequent myolysis had benefits in conserving the uterus, and was less invasive, and had great effect on the reducing the size of the leiomyoma and improving the symptoms, and also returning to normal life pattern was earlier. But in women with adenomyosis the symptoms were worsened after approximately 6 to 9 months after the procedure. Therefore additional research and follow-up is required and a strict criterion is needed.

국방혁신 4.0 추진을 위한 국방연구개발 시제품 활용방안 연구

류지훈(Ji-Hoon Ryu) 한국해군과학기술학회 2023 Journal of the KNST Vol.6 No.1

In all weapons system development projects, prototypes are manufactured by integrating major equipment, subsystems, core parts & components and technologies. Prototypes are used in the R&D process and weapon system performance test evaluation to solve system errors. After this process is completed, it is stored for recycling in subsequent research and development projects, but it is not recycled due to restrictions. This study comprehensively considers the management system and utilization of prototypes to review more valuable and effective use of prototypes. In addition, it proposes a new utilization method that can contribute to the promotion of Defense Innovation 4.0 while resolving various problems related to prototypes.

핵종거동 자연유사연구의 중요성과 적용성

백민훈(Min-Hoon Baik),류지훈(Ji-Hun Ryu) 대한지질학회 2021 대한지질학회 학술대회 Vol.2021 No.10

고준위방사성폐기물 심층처분을 고려하고 있는 국가들에서는 처분안전성 확보 및 처분시스템에 대한 신뢰도 증진을 위한 방안으로 Safety Case를 개발하여 적용하고 있다. 이러한 Safety Case에 필요한 다중의 해석, 논의, 증거를 제시하기 위한 방안의 하나로 자연유사연구가 있다. 심층처분기술과 처분안전성에 대한 인식에는 일반 대중뿐만 아니라 정책결정자, 규제자, 연구개발자, 사업자 등 다양한 이해관계자들 사이에서도 상당한 인식의 차이가 있다. 따라서 자연유사연구는 처분시스템과 유사한 자연 및 인공의 유사물들을 이용한 연구결과를 바탕으로 이러한 간극을 줄일 수 있는 수단을 제공한다. 따라서 본 연구에서는 먼저 방사성폐기물 처분에서 자연유사연구의 중요성과 Safety Case로의 다양한 활용방안을 논의하였다. 그리고 심층처분환경에서 핵종거동과 관련된 대규모의 자연유사연구들(가봉의 Oklo Natural Reactor, 캐나다의 Cigar Lake, 호주의 Alligator River, 브라질의 Poços de Caldas 등)의 개요와 연구결과의 의의 및 교훈, 그리고 연구결과의 불확실성과 한계점 등을 논의함으로써 자연유사연구결과의 적용성을 분석하였다. 자연유사연구 정보자료들은 지질학적 시간대에 걸친 방사성폐기물 형태와 방사성폐기물 처분장의 성능에 중요한 정보를 제공할 수 있다. 또한 처분안전성평가모델들에서 자연유사연구 결과들을 사용하는 것은 몇 가지 중요한 한계들로 인해 조심해야 하며, 자연유사연구 정보자료를 신뢰성 있게 활용하기 위해서는 자연유사 연구 결과들의 한계성과 실제 처분시스템과의 차이점을 파악하고, 적합성과 타당성을 분석하여야 한다. 특히 고준위폐기물 처분장의 안전성과 성능에 대한 신뢰성을 확보하기 위해 대중들에게 과장된 자연유사연구 결과를 제시하는 것을 주의해야 한다. 자연유사연구는 처분안전성평가에서 매우 다양한 방법으로 중요한 역할을 수행하고 있지만, 처분 안전성 평가에서의 적극적인 활용은 아직도 매우 제한적이다. Safety Case를 통한 처분안전성 평가 및 확보가 중요한 현 시점에서는 자연유사연구 결과의 보다 적극적인 활용방법론 개발과 함께 관계자들의 인식의 전환이 필요하다고 사료된다.

KURT 화강암 내 우라늄의 지화학적 용출특성에 미치는 용존이온의 영향

조완형,백민훈,류지훈,이재광,Cho, Wan Hyoung,Baik, Min Hoon,Ryu, Ji-Hun,Lee, Jae Kwang 한국방사성폐기물학회 2018 방사성폐기물학회지 Vol.16 No.3

In order to understand the long-term behavior of radionuclides in granite environments, geochemical behavior characteristics of uranium in granitic host rock of KURT (KAERI Underground Research Tunnel) were investigated by dissolution experiment with different reaction time and solutions. In the dissolution experiment, significantly increased dissolution levels of uranium from granite powder samples were identified during the reaction time of 0~10 days for reaction solutions ($UD-CO_3$ and UD-Bg) containing a large amount of $CO_3{^{2-}}$. On the other hand, significantly increased dissolution levels of uranium were also identified for reaction solutions containing Na and Ca after 60 days. Dissolution of uranium continuously increased in reaction solutions of $UD-CO_3$ ($44.61{\mu}g{\cdot}L^{-1}$), UD-Bg ($41.01{\mu}g{\cdot}L^{-1}$), UD-Na ($26.87{\mu}g{\cdot}L^{-1}$), UD-Ca ($20.26{\mu}g{\cdot}L^{-1}$), UD-CaSi ($17.03{\mu}g{\cdot}L^{-1}$), and UD-Si ($10.47{\mu}g{\cdot}L^{-1}$) in the experimental period of ~270 days. However, after day 270, dissolution of uranium showed a decreasing tendency. This is thought to have occurred because existing uranium in granite samples reached the limit of dissolution by interaction with reaction solutions. Concentrations of dissolved uranium and points of maximum concentration value were found to differ depending on the $CO_3{^{2-}}$ presence in the mixed reaction solution and on the geochemical type of the water. It is estimated that differences in the reaction rate between the granite sample and the reaction solution are due to the influence of dissolved ions in the reaction solution.

한국형잠수함 리튬전지모듈 소화장치 개발 및 실증 연구

연제길(Jaegil Yeon),류지훈(Ji-Hoon Ryu) 한국해군과학기술학회 2024 Journal of the KNST Vol.7 No.1

The Jang Bogo-III Batch-II class submarine, which has been under construction since 2019, is scheduled to be equipped with lithium-ion batteries as storage batteries. Lithium-ion batteries have the advantage of having higher energy density and electromotive force compared to other secondary batteries and are easy to charge and discharge, but they have the inherent risk of explosion and fire due to physical damage, temperature rise, and thermal runaway due to chemical defects. Therefore, in order to operate a large amount of lithium batteries in a submarine that operates isolated at sea, an effective fire safety device is required. In this regard, this study introduces the development status and field demonstration results of a module-based fire extinguishing device that can be completely controlled even in the event of a lithium-ion battery fire to enable stable operation of large quantities of lithium-ion batteries in Submarine.

Bioreduction of U(Ⅵ) by indigenous bacteria present in deep granitic groundwater

Dawoon Jeong(정다운),Min Hoon Baik(백민훈),Euo chang Jung(정의창),Myoung-Soo Ko(고명수),Wooyong Um(엄우용),Ji-Hun Ryu(류지훈) 대한환경공학회 2022 대한환경공학회 학술발표논문집 Vol.2022 No.11

민수용 ESS 화재사례를 고려한 잠수함용 리튬전지체계 안전성 설계 및 검증

연제길(Jaegil Yeon),류지훈(Ji-Hoon Ryu) 한국해군과학기술학회 2023 Journal of the KNST Vol.6 No.3

Most conventional submarines are trying to increase their storage capacity to stay submerged for longer periods without a snorkel. In Korea, the Jang Bogo-III Batch-II class, which is currently under construction, will be equipped with lithium batteries to increase storage capacity. Compared to lead-acid batteries, lithium batteries can store large amounts of energy and are advantageous in terms of durability as well as maintenance. . In this respect, this study presents a safety design plan and verification results so that a large amount of lithium batteries can be stably operated in a special and limited space such as a submarine.

보존적 요법으로 치료한 자궁 소낭 내 감입 태반

정민 ( Min Choung ),노정훈 ( Jeong Hoon Rho ),손창업 ( Chang Up Son ),나우석 ( Woo Suk Na ),이병관 ( Byung Kwan Lee ),송영래 ( Young Rae Song ),류지훈 ( Ji Hoon Ryu ),황인택 ( In Taek Hwang ),김기환 ( Ki Hwan Kim ) 대한주산의학회 2007 Perinatology Vol.18 No.3

Uterine sacculation is a very rare complication associated with pregnancy in which a part of the uterine wall balloons, and it is difficult to diagnose because it is usually asymptomatic. It frequently contains the placenta and sometimes may be involved with the trapped placenta after delivery due to its structural characteristic. It is impossible to remove the retained placenta in the sac by using usual methods such as manual delivery or curettage so most of patients with it end up with having a laparotomy. Especially, if the placenta in it is accompanied by abnormal adherence of the placenta or serious hemorrhage, hysterectomy should be considered. Currently several conservative methods for the retained placenta including selective uterine artery embolization and administration of methotrexate have been introduced and these may be tried to treat the retained placenta in the uterine sacculation for avoiding operation and preserving future reproductive potential in selective cases. We experienced a case of placenta increta in the uterine sacculation that was diagnosed first during cesarian section and was treated with selective uterine artery embolization followed by methotrexate administration. This case is reported with a brief review of the literatures.