석골재자원 개발을 위한 균열제어 발파모델 연구

임한옥,김재동,김종훈,백승규 강원대학교 석재복합신소재제품연구센터 1998 석재연 논문집 Vol.3 No.-

본 연구에서는 석골재 자원개발에서 널리 사용되고 있는 발파 조건을 고려하여 암반의 변형 및 파괴거동에 대한 특성을 규명하기 위한 컴퓨터 모델링을 시도하였다. 현재까지 이루어진 몇몇 연구들은, 발파에 의한 암반의 거동을 실제 동하중이 적용되고 있는 상태와는 달리 정적 상태 하의 조건에서 주로 이루어져 왔다. 그러나 실제 발파 거동은 동적 거동을보이므로 동역학적 해석을 하지 않을 경우 많은 오차를 포함한 상태하의 개괄적인 특성의 추정에 그칠 수밖에 없는 단점을 지니고 있었다. 본 연구에서는 동하중 하에서의 탄소성 해석을 실시하여 채석시 발파 하중에 대한 암반의 하중 반응, 탄성 및 소성 변형의 발생 특성, 그리고 이로 인한 발파 균열의 성장 전파 특성을 규명함으로써 발파로 인한 균열의 능동적 제어와 보다 효율적인 발파가 이루어 질 수 있는 조건들을 규명하고자 하였다. 해석 결과 일반 발파공의 경우에서 탄성 모델의 경우 공반경의 약 3배인 6cm까지 집중된 응력의 크기가 파괴강도를 초과하는 것으로 나타났으며, 탄소성 모델의 경우 균열의 전파 거리는 공반경의 15배인 30cm까지 균열이 확장되었다. 또한 폭 5mm 길이 20mm의 노치가 가공된 발파공의 경우 공반경의 25배인 50cm까지 균열이 진전되었으며, 균열의 방향은 노치 첨단의 방향으로 생성되는 것을 알 수 있다. 노치의 폭과 길이에 의한 영향은, 폭은 10mm이하일 경우가 적합하다고 판단되며, 길이는 균열의 성장 길이에 비례하는 경향이 있는 것을 알 수 있었다. Conditions for developing an effective controlled blast model were studied using finite element method, analyzing elastic and elasto-plastic case under static and dynamic load for normal blast hole and notched blast hole. Results show that from the elastic analysis of normal blast hole with 2 cm radius, stress concentrated by blasting exceeds tensile strength for the region up to 6 cm from hole wall and in case of elasto-plastic analysis, it was expanded up to 30 cm. For the notched blast hole with its width of 5mm and length 20mm, crack due to blasting was propagated up to 50 cm.

"지황 1호"를 이용한 숙지황 제조기술 연구

박남규,김선림,허한순,박충현 한국국제농업개발학회 2002 韓國國際農業開發學會誌 Vol.14 No.1

재래종 지황과 신육성품종 지황 1호를 이용하여 절단 및 원형으로 숙지황을 제조한 결과는 다음과 같다. 1. 가압에 의한 숙지황 제조시간이 재래종은 254∼264시간, 제품수율이 71.42∼71.48%였고, 지황 1호는 제조시간이 260∼276시간 소요되었고, 수율은 71.50∼71.51%였으며 중량은 감소하는 경향이었다. 2. 상압에 의한 숙지황 제조에서도 가압에 의한 제조와 비슷한 경향을 보였다. 3. 가압과 상압에 의한 숙지황 제조 후 유리당 조성은 재래종, 지황 1호 전처리구에 63∼65% 이상이 fructose였으며, 30% 이상이 glucose였고, sucrose, maltose가 함유되었다. 4. 가압 및 상압에 의한 숙지황 제조시 catalpol 함량 변화는 종자회수가 많아질수록 caltalpol 함량이 낮아지는 경향이었으나 완전히 없어지지는 않았다. 5. 숙지황 제조 후 포장재별로 포장하여 상온에 저장한 결과 제품에 곰팡이 발생이 없어 저장에 문제가 없었다. New processing method for R. Radix preparata was developed by using the landrace variety as a control and "Jiwhang 1" (Rehmannia glutinosa Liboschitiz). Sliced Rehmanna glutionsa Liboschitiz was steam heated by normal and high pressure conditions for the round-shaped R. Radix preparata processing. About 254 to 264 hours were required for the processing of domestic variety, and about 260 to 280 hours were required for "Jiwhang 1", but their yields were ranged about 71.42∼71.6%. Fructose and glucose were major free sugar of R. Radix preparata, and their composition rates were 63∼65% and 30%, respectively, but sucrose and maltose were traced only small amount. The Catalpol content was decreased as increasing the frequencies of steam heating repetion. But the catalpol was not completely removed. After processing, R. Radix preparata packed with paper-bag or PE-bag, and storaged at common temperature was keeping a best quality.

還魂散(內消散) 물 엑스 및 20% 에탄올 엑스의 消炎, 鎭痛, 抗菌作用에 관한 硏究

金鍾翰,黃忠演,林圭庠 圓光大學校 韓醫學硏究所 1994 원광한의학 Vol.4 No.1

These experiments were conducted to investigate the anti-inflammatory, analgesic and anti-bacterial activity of Hwanhonsan(HHS) water ext. and 20% EtOH ext. The results were summarized as follows ; The inhibitory effect on the leakage of evans blue into peritoneal cavity was significantly increased by HHS water ext. and EtOH ext, respectively. The paper disk granuloma formation displayed more potent effcet than the control group in EtOH ext. Mouse paw edema induced by histamine was significantly decreased by HHS water ext. and EtOH ext. HHS water ext. and EtOH ext. inhibited the protein exudation in rats. The analgesic activity on 0.7% acetic acid induced writhing syndrome was significantly shown by EtOH ext. Anti-bacterial activity was shown by HHS water ext. and EtOH ext., respectively.

측두골 골절에 의한 재발성 뇌막염 1례

정학현,고태옥,서한규,임현호,황순재 한국의학사 1998 診斷과治療 Vol.18 No.2

Aortocaval Fistula by Luetic Abdominal Aortic Aneurysm : Report of a case

Lim, Sang Hyun,Lee, Cheol Joo,Roh,Hwan-Kyu,Kim, Dae Jun,Han, Jung Sun,Shin, Joon Han,Kim, Han Soo 아주대학교 1996 아주의학 Vol.1 No.2

A 53-year-old male patient was operated on because of a spontaneous abdominal aortic aneurysm with aortocaval fistula. The fistula was successfully closed and bifurcated woven Dacron graft was used to replace the aneurysm. The patient had with characteristic signs and symptoms of aortic aneurysm with arteriovenous fistula. Proper diagnosis and prompt surgical repair of aortocaval fistula saved the patient. The use of rapid infusion system provided stable hemodynamics during the operation.

Cryopreservation of Semen in Dead Yellow Croaker, Larimichthys polyactis

Han Kyu Lim,Byung Hwa Min,Min Hwan Jeong,Byul Nim Choi,Minh Hoang Le,Young Jin Chang 한국수산과학회 2010 Fisheries and Aquatic Sciences Vol.13 No.4

This study demonstrated that cryopreserved semen from dead fish can be used for seedling production. Yellow croakers, Larimichthys polyactis, were killed and stored at temperatures of 20°C or 0°C for 6 hours. At 2 hour intervals, semen from these fish was collected using abdominal pressure and evaluated for spermatozoa motility and semen cryopreservation. Semen collected after 6 hours from dead fish stored at 0°C could be cryopreserved and attained fertilization and hatching rates of 15.0±1.2% and 14.8±1.6%, respectively. This study suggests that germ cells such as the semen of dead fish can be cryopreserved and utilized in the restoration of a species.

Generation of CD2<SUP>+</SUP>CD8<SUP>+</SUP> NK Cells from c-Kit<SUP>+</SUP> Bone Marrow Cells in Porcine

Kyu Hee Lim,Ji-Hui Han,Yoon Seok Roh,Bumseok Kim,Jung-Kee Kwon,Myoung Jo You,Ho Jae Han,Sohail Ejaz,Chang-Won Kang,Jong-Hoon Kim 대한생리학회-대한약리학회 2012 The Korean Journal of Physiology & Pharmacology Vol.16 No.3

Natural killer (NK) cells provide one of the initial barriers of cellular host defense against pathogens, in particular intracellular pathogens. Because bone marrow-derived hematopoietic stem cells (HSCs), lymphoid protenitors, can give rise to NK cells, NK ontogeny has been considered to be exclusively lymphoid. Here, we show that porcine c-kit⁺ bone marrow cells (c-kit⁺ BM cells) develop into NK cells in vitro in the presence of various cytokines [interleukin (IL)-2, IL-7, IL-15, IL-21, stem cell factor (SCF), and fms-like tyrosine kinase-3 ligand (FLT3L)]. Adding hydrocortisone (HDC) and stromal cells greatly increases the frequency of c-kit⁺ BM cells that give rise to CD2⁺CD8⁺ NK cells. Also, intracellular levels of perforin, granzyme B, and NKG2D were determined by RT-PCR and western blotting analysis. It was found that of perforin, granzyme B, and NKG2D levels significantly were increased in cytokine-stimulated c-kit⁺ BM cells than those of controls. And, we compared the ability of the cytotoxicity of CD2⁺CD8⁺ NK cells differentiated by cytokines from c-kit⁺ BM cells against K562 target cells for 28 days. Cytokines-induced NK cells as effector cells were incubated with K562 cells as target in a ratio of 100:1 for 4 h once a week. In results, CD2⁺CD8⁺ NK cells induced by cytokines and stromal cells showed a significantly increased cytotoxicity 21 days later. Whereas, our results indicated that c-kit⁺ BM cells not pretreated with cytokines have lower levels of cytotoxicity. Taken together, this study suggests that cytokines-induced NK cells from porcine c-kit⁺ BM cells may be used as adoptive transfer therapy if the known obstacles to xenografting (e.g. immune and non-immune problems) were overcome in the future.

Tunable piezoelectric nanogenerators using flexoelectricity of well-ordered hollow 2D MoS₂ shells arrays for energy harvesting

Han, Jin Kyu,Kim, Sungho,Jang, Seunghun,Lim, Yi Rang,Kim, Sang-Woo,Chang, Hyunju,Song, Wooseok,Lee, Sun Sook,Lim, Jongsun,An, Ki-Seok,Myung, Sung Elsevier 2019 Nano energy Vol.61 No.-

<P><B>Abstract</B></P> <P>Piezoelectric two-dimensional (2D) transition-metal dichalcogenides such as molybdenum disulfide (MoS<SUB>2</SUB>) have recently attracted significant attention owing to their applicability for fabrication of flexible power generators. In this study, novel piezoelectric nanogenerators (PNGs) consisting of 2D piezoelectric MoS<SUB>2</SUB> shells are fabricated where an Al<SUB>2</SUB>O<SUB>3</SUB> thin layer deposited on the surface of polystyrene (PS) beads is used to avoid collapse of the spherical MoS<SUB>2</SUB> shells under the high growth temperature. In addition, the MoS<SUB>2</SUB> shell size is controlled by adjusting the PS bead size and the effects of the MoS<SUB>2</SUB> shell size on power generation characteristics are investigated. Our PNG based on the piezoelectric MoS<SUB>2</SUB> shells produces a peak output voltage of approximately 1.2 V at a pressure of 4.2 kPa. The minimum pressure for power generation by tapping is 0.3 kPa. This novel method is very promising for development of the next-generation PNGs based on 2D semiconductor piezoelectric materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel piezoelectric nanogenerators (PNGs) consisting of 2D piezoelectric MoS<SUB>2</SUB> shells were fabricated. </LI> <LI> The effect of the MoS<SUB>2</SUB> shell size on power generation characteristics was investigated. </LI> <LI> The output voltage of 1.2 V was measured under the pressure of 4.2 kPa by using MoS<SUB>2</SUB> shell-based PNGs. </LI> <LI> High-power generation properties and nonlinear hysteresis behavior were observed for the micrometer-scale MoS<SUB>2</SUB> shells. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effect of diluent variation on cryopreservation of large yellow croaker Larimichthys crocea

Lim, Han Kyu,Irfan, Zidni,Lee, Hyo Bin,Song, Ji Hoon,Lee, Yun Ho The Korean Society of Fisheries and Aquatic Scienc 2021 Fisheries and Aquatic Sciences Vol.24 No.2

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein's solution, Hank's balanced salt solution, marine fish Ringer's solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below -10℃/min. The thawing temperature of 45℃ was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p < 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.

A Network Storage LSI Suitable for Home Network

Han-Kyu Lim,Ji-Ho Han,Deog-Kyoon Jeong 대한전자공학회 2004 Journal of semiconductor technology and science Vol.4 No.4

Storage over Ethernet (SoE) is a network storage architecture that allows direct attachment of existing ATA/ATAPI devices to Ethernet without a separate server. Unlike SAN, no server computer intervenes between the storage and the client hosts. We propose a SoE disk controller (SoEDC) amenable to low-cost, single-chip implementation that processes a simplified L3/L4 protocol and converts commands between Ethernet and ATA/ATAPI, while the rest of the complex tasks are performed by the remote hosts. Thanks to simple architecture and protocol, the SoEDC implemented on a single 4mmx4mm chip in O.18um CMOS technology achieves maximum throughput of 55MB/s on Gigabit Ethernet, which is comparable to that of a high-performance disk storage locally attached to a host computer.