Kinetics of Hydrogen Movement in Zinc

Jeong_Keun Lee 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.II

The diffusivity of hydrogen in pure zinc was determined by using hydrogen extraction with cylindrical specimens of 1 cm in diameter and 1 cm in length. The measured values of the diffusivity did not vary statistically with the purity of the zinc, which indicates that the grain boundary did not play an important role in the hydrogen evolution from zinc. The values of the diffusivity obtained in the temperature range from 50 to 300 $^\circ$C showed that the diffusivity depended exponentially on the temperature. The repeatability of the hydrogen extraction method at low temperatures was better than that at high temperatures. A combination of the measured value of the frequency factor, $D_0$, with Zenner's theoretical expression of $D_0$ for interstitial diffusion yielded a negative value of the activation entropy, $\Delta S$, which was explained by the hypothesis that the change in the vibrational frequency of hydrogen particles that jumped between adjacent sites contributed more to $\Delta S$ than the zinc lattice distortion caused by the movement of hydrogen particles did.

급성 충수돌기염 의증 환자의 진단에서 컴퓨터 단층촬영과 초음파검사의 비교 분석

이정훈,최필조,심민섭,송근정,정연권 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: This study was conducted to compare the accuracy of computered tomography(CT) and sonography(US) in diagnosing acute appendicitis and to analyze the radiologic factors which influence the result. Methods: We retrospectively studied the cases of 53 patients who were suspected of having appendicitis and who were examined by CT and US covered a three-year period. The final diagnosis was determined from the surgico-pathologic diagnosis and clinical follow-up for two months, as well as from the discharge diagnosis. Results: Thirty-eight(38) patients had acute appendicitis; 15 patients did not. In the analysis, CT and US, respectively, revealed sensitivities of 89.5% and 73.7%, specificities of 93.3% and 60.0%, positive predictive values of 97.1% and 82.4%, negative predictive values of 77.8% and 47.4%. Among patients diagnosed with acute appendicitis, 10 patients were discordant in the US and the CT examinations; CT findings were correct in 8 and US findings in 2. Among non-appendicitis patients, 5 patients were discordant in the US and the CT examinations; CT was correct in 5 and US in 0. Nighteen(19) patients had complications such as an abscess or a perforation. Among these patients, the degree and the extent of the complication were accurately evaluated by CT in 15 patients and by US in 5 patients. Conclusion: CT is more accurate than US in diagnosing and excluding acute appendicitis. The use of CT will substantially decrease unnecessary laparotomies and post-operation complications.

불완전 전뇌 허혈후 소생의 백서 모델을 이용한 재관류 뇌혈류량과 허혈성 뇌조직 손상도와의 관계

서정필,송근정,황태식,정연권,신백효,김승호 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: Experimental data indicate that low-flow reperfusion following prolonged cardiocirculatory arrest may aggravate early cerebral microcirculatory reperfusion disorders. We investigated the influence of cerebral reperfusion flow change to the ischemic histopathologic damage of brain tissue after incomplete forebrain ischemia in rats. Materials and method: Anesthetized Sprague-Dawley rats were undergone ligation of both internal carotid artery by microvascular clamp for 10 minutes. After release of the clamp, reperfusion was started with several different flow levels (0, 10, 20, 30, 50, and 100%) of internal carotid artery comparing to pre-clamping phase using flowmeter. After 15minutes of reperfusion, rat brains were prepared by perfusion-fixation with 3% formaldehyde. Under light microscopic examination of Hematoxylin-Eosin stained tissue slide, histopathologic damage was examined at cortex, putamen, and hippocampus regions. Categorical hisotopathologic damage scores were derived in each regions by manual counts of ischemic neurons. Result: The histopathologic damage scores were 0, 10.2±0.5, 7.6±1.5, 5.9±1.4, 5.0±2.8, 3.5±0.7, and 1.0±0.0 in control, 0, 10,20, 30, 50, and 100% reperfusion groups, respectively(p<0.05). Conclusion: Our results showed significant increment of brain histopathologic damage scores along with decreasing amount of cerebral reperfusion flow after incomplete forebrain ischemia. We believe restoration of reperfusion flow to pre-ischemic level would be a critical component in attenuation of brain ischemic damage.

Identification of Genes Modulated by High Extracellular Calcium in Coculture of Mouse Osteoblasts and Bone Marrow Cells by Oligo Chip Assay

Kim, Hyung-Keun,Song, Mina,Jun, ji-Hae,Woo, Kyung-Mi,Kim, Gwan-Shik,Baek, Jeong-Hwa The Korean Academy of Oral Biology 2006 International Journal of Oral Biology Vol.31 No.2

Calcium concentration in the bone resorption lacunae is high and is in the mM concentration range. Both osteoblast and osteoclast have calcium sensing receptor in the cell surface, suggesting the regulatory role of high extracellular calcium in bone merabolism. In vitro, high extracellular calcium stimulated osteoclastogenesis in coculture of mouse osteoblasts and bone marrow cells. Therefore we examined the genes that were commonly regulated by both high extracellular calcium and 1,25(OH)_(2)vitaminD_(3)(VD3) by using mouse oligo 11 K gene chip. In the presence of 10 mM[Ca^(2+)]e or 10 nM VD3, mouse calvarial osteoblasts and bone marrow cells were co-cultured for 4 days when tartrate resistant acid phosphatase-positive multinucleated cells start to appear. Of 11,000 genes examined, the genes commonly regulated both by high extracellular calcium and by VD3 were as follows; 1) the expressions of genes which were osteoclast differentiation markers or were associated with osteoclastogenesis were up-regulated both by high extracellular calcium and by VD3; trap, mmp9, car2, ctsk, ckb, atp6b2, tm7sf4, rab7, 2) several chemokine and chemokine receptor genes such as sdf1, scya2, scyb5, scya6, scya8, scya9, and ccr1 were up-regulated both by high ectracellular calcium and by VD3, 3) the genes such as mmp1b, mmp3 and c3 which possibly stimulate bone resorption by osteoclast, were commonly up-regulated, 4) the gene such as c1q and msr2 which were related with macrophage function, were commonly down-regulated, 5) the genes which possibly stimulate osteoblast differentiation and/or mineralization of extracellular matrix, were commonly down-regulated;slc8a1, admr, plod2, lox, fosb, 6) the genes which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were commonly up-regulated;s100a4, npr3, mme, 7) the genes such as calponin 1 and tgfbi which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were up-regulated by high extracelluar calcium but were down-regulated by VD3. These results suggest that in coculture condition, both high extracellular calcium and VD3 commonly induce osteoclastogenesis but suppress osteoblast differentiation/mineralization by regulating the expression of related genes.

응급실에서 시행된 기관내 삽관의 현황

김병철,강보승,송형곤,이정훈,송근정,정연권 대한응급의학회 1999 대한응급의학회지 Vol.10 No.4

Background : The purpose of this study was to analyze the endotracheal intubation cases performed in the emergency department. Methods : We investigated retrospectively 326 cases of endotracheal intubation performed in the emergency department of a tertiary care center form April 1, 1998 to March 31, 1999. We focused on operators, medications used, its success rate and immediate complications, and the relationship between its success rate and medications. Results : Of 326 consecutive intubations, 193 patients(59.2%) were done by emergency medicine residents or attending physician. While 320 patients(98.2%) were successfully intubated, 6 patients could not be intubated and 2 patients underwent tracheostomy. Of 50 cases of intubations(15.3%) attempted with paralyzing agents, 48 cases were done with succinylcholine and 46 cases underwent by emergency physicians. Intubations with neuromuscular paralysis resulted in high success rates at the first attempt. Of 55 immediate adverse events were encountered in 47 patients(desaturation=17, bronchial intubation=15, hypotension=8, bradycardia=4, cardiac arrest=2, others=5). Conclusion : At this institution, paralyzing agents were used infrequently, but almost all of them were used by emergency physicians.

퍼지 추론을 기반으로 한 컬러 영상에서의 감성 인식

정근호,오재흥,주영훈 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

In this paper, we propose the technique for recognizing the human's emotion by using the color image. To do this, Detect face using skin color abstraction method from color image. And we propose the method for finding man's feature points(eyebrows, eye, nose, mouse) from the face image and the geometrical method for recognizing human's emotion (surprise, anger, happiness, sadness) from the structural correlation of man's feature points. The proposed method in this paper recognize the human's emotion by the Fuzzy. Finally, we have proven the effectiveness of the proposed method through the experimentation.

자연재해에 따른 경제적 손실 평가를 위한 한국형 모형 개발 - 홍수재해를 중심으로

정근채 충북대학교 건설기술연구소 2008 충북대학교 건설기술연구소 논문집 Vol.27 No.1

charateristics from the hazard environments of Korea. The proposed model classifies physical assets into five categories: building, facility, utility system, transportation system, and agricultural/livestock system, and then identifies loss functions for estimating economic losses by applying the output from the damage functions to the asset inventory information. The loss functions classify the economic losses into the first direct/physical losses and the second indirect/additive losses and information system tor evaluationg economic losses from natural hazards can be developed based on the proposed model and the resulting system can be used as a useful tool for analyzing the feasibilities of mitigation plans in central/local governments.

천공된 비특이성 결장 궤양에 의한 후복막 기종 1예

임정근,김정용,박찬국 대한대장항문학회 1994 Annals of Coloproctolgy Vol.10 No.4

한·미·일 생산성의 요인별 비교 : 비모수적 접근법 Nonparametric Malmquist Approach

정기호,정근존 慶北大學校出版部 2004 經商論集 Vol.32 No.1

This research measures productivities of private sector and government sectors in Korea using Malmquist productivity index, decomposes them into two factors of catching-up and innovation, and compares the productivities among Korea, USA and Japan. Additionally, this research tests Granger-causality between the productivity of Korea and the productivities of USA and Japan.

Methylmethacrylate와 n-Butylalcohol의 에스테르 교환반응에 관한 연구

鄭舜旭,朴根浩,孫秉淸,金忠一 弘益大學校 1988 弘大論叢 Vol.20 No.2

The transesterification reaction between methylmethacrylate and n-butyl alcohol was kinetically investigated in the presence of constant quantity of inhibitor and various metal acetate catalyst at 120℃. The quantity of n-butylmethacrylate produced in the reaction flask was measured by gas-chromatography, and the reaction rate was investigated by measuring of the quantity of the product the reaction under various catalysts. The transesterification was carried out in the first order reaction kinetics with respect to the concentration of methylmethacrylate and n-buty1 alcohol, respectively. The linear relationship was show between rate constant and absolute temperatures, and the activation energy of 14.7Kcal for the reaction with zinc acetate catalyst was calculated. The maximum reaction rate was appeared at the range of 1.5 to 1.6 of electro-negativity of metal ions.