Investigation on Delamination Characteristics of 2-Ply Clad Metals and Adhesive Joints for Aluminum/Stainless Steel via the Peel Test

Jun‑Hyung Sim,Yungeun Ha,Min‑Kyun Kim,Min‑Joong Kim,Young‑Rae Cho 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

Bonding properties are important for metallic multilayer composites (MMCs) comprising different materials or materialswith different mechanical properties. In this study, we fabricated 2-ply Al/stainless steel (STS) clad metals and Al/adhesive(adh)/STS joints. To manufacture samples with various mechanical properties, T6 heat treatment was performed on cladmetals, and adhesive joints of several thicknesses were prepared. For each sample, the bonding strength was characterizedvia a T-peel test and the results were analyzed using the peeling angle. For 2-ply Al/STS clad metals, the T6 heat treatmentresulted in opposite trends in the mechanical properties. The bonding strength of 2-ply Al/STS clad metals was affectedby the peeling angle, i.e., a small peeling angle provided a small bonding strength at the interface. However, for the 2-plyAl/adh/STS joints, the bonding strength of adhesives on metals depended on each adherend of the stress state. As the differencein mechanical properties between the two adherends increased, the difference in each peeling angle of Al and STSalso increased. The peeling angle of adherends reached a limiting value when the sample contacted the clamping jig head;therefore, a new term, apparent bonding strength (ABS), is necessary to differentiate this new strength from the bondingstrength obtained under non-contact conditions. We believe that the concept of peeling angle and ABS proposed herein willplay a crucial role in describing the delamination behavior and bonding strength of MMCs via the peel test.

The Load Model Composition Method in Power Systems Using Artifcial Neural Network

Rae‑Jun Park,송경빈,Kyungsang Lee 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.2

An accurate load model is necessary to improve the accuracy of power systems dynamic stability analysis. Recent studies to estimate accurate load model have mainly been focused on the measurement-based load modeling and the method to estimate a single representative load model called load model composition or load representation. The current load model used for the dynamic stability analysis in South Korea power system was aggregated with the measurement data from only three distribution stations. The proposed algorithm is the load model composition method based on artifcial neural network technique using more measurement data than the algorithm to estimate the current load model. The proposed load model composition method using the artifcial neural network uses the load composition ratio as the input value and the ZIP model parameter, which is the estimation result at each distribution line, as the output value. The measurement data to estimate the parameter were collected from 105 distribution lines of 9 substations. The performance of proposed algorithm was verifed for three perspectives in the case studies. The accuracy of the proposed algorithm has been improved by comparing the measurement data with the calculated result by using the proposed model. The mean absolute percentage error (MAPE) between the measured data and the proposed model is 1.7%. The proposed algorithm could be applied to estimate the representative load model using data measured at multiple measurement points.

기관내 삽관시 Flexiblade 후두경과 Macintosh 형 후두경 사용에 대한 비교

장선영,이상귀,이준례 대한마취과학회 2001 Korean Journal of Anesthesiology Vol.41 No.3

Comparison between the Flexiblade Laryngoscope and the Macintosh Blade Laryngoscope in Endortracheal Indubation Sun-Young Jand, M.D., Sang-Kyi Lee, M.D., and Jun-Rae Lee, M.D. Department of Anesthesiology, Chonbuk National University Medical School, Jeonju, Korea Background: The Flexiblade laryngoscope has a unique structure that is composed of a blade and a handle with a trigger. When the trigger of the Flexiblade laryngoscope is squeezed, the hyoepiglottic ligament is depressed, the epiglottis is moved anteriorly, and then the laryngoscopic grade is improved. This study was designed to compare the Flexiblade laryngoscope with the conventional Machintosh blade laryngoscope in the laryngoscopic view in endotracheal intubation. Methods: Following induction of general anesthesia, the laryngoscopic grades of 110 patients were evaluated while five different blade positions of the Flexiblade laryngoscope and a laryngoscopy with the Macintosh blade were performed. The laryngoscopic grades which were described by Cormack and Lehane were classified from 1 to 4. Results: With the Macintosh blade laryngoscope, 98.2% of the patients were grade one and two, and 98.2% of the patients was laryngoscopic grade one and two with partial depression of the trigger of the Flexiblade laryngoscope. The laryngoscopic grade of maximal depression of the Flexiblade trigger had similar results to partial depression of the trigger. However, the partial depression of the Flexiblade laryngoscope showed better laryngoscopic views than the maximal depression of the Flexiblade laryngoscope or the Macintosh blade laryngoscope, respectively. In the overall success rate of endo-tracheal intubation and using the adjusting maneuvers, the Flexiblade laryngoscope was superior to the Macintosh blade laryngoscope. Conclusions: The Flexiblade laryngoscope is comparable to the Macintosh blade laryngoscope for endotracheal intubation, therefore, the Flexiblade laryngoscope can be recommended as the first choice for endotracheal intubation. (Korean J Anesthesiol 2001; 41: 289~296)

과량의 인슐린 투여로 인한 인위성 저혈당증 1예

김준우,안철우,남주영,김똘미,김영균,추적금,박종숙,박진아,조승현,김동연,김도연,윤수지,이경열,차봉수,김경래,임승길,이현철,허갑범 대한당뇨병학회 2002 임상당뇨병 Vol.3 No.2

본 저자들은 인위적인 인슐린 투여로 인한 인간성 저혈당증 1예에서 보존적인 치료로 의식기능은 회복하였으나, 현저한 인지능력 저하를 하였기에 문헌고찰과 함께 보고하는 바이다. Factitious hypoglycemia is a covert attempt to lower the blood glucose concentration with insulin or a sulfonylurea agent. This attempt is mainly performed by the patients themselves. In a large series of diabetics who had overdosed on drug, less than 5% had used insulin for suicidal or homicidal purposes. Additionally, 4 of 204 hypoglycemic episodes were due to a suicide attempt with insulin. The onset of insulin action, its peak level, and duration, and the degree of hypoglycemia, are determined by insulin's pharmacokinetics. However, the final outcomes are not associated with the amount of insulin used. The complications related to insulin overdose are cerebral damage and hypokalemia. Other complications include, pulmonary edema attributed to congestive heart failure and hypertensive crisis, as well as respiratory insufficiency. We report this case with a review of the literature.

초오 중독 환자의 임상적 고찰

이준희,김경래 대한응급의학회 1995 대한응급의학회지 Vol.6 No.1

Background : In Korea, the roots of Aconitum species had long been prescibed in the herb medicine, but is still used sometimes as a folk remedy for the purpose of analgesics, antiinflammatory, or cardiotonics, resulting in serious intoxication due to its low safety margin. Study objectives : This study was conducted to document the adverse effects related aconitine and to determine the outcome in these patients. Study objectives : This study was conducted to document the adverse effects related aconitine and to determine the outcome in these patients. Study Subject : A retrospective survey was conducted of 12 patients admitted to the Inha hospital with a history of acute aconitine poisoning over a five year period from 1990 to 1994. Results : All patients represented very similar features. The symptoms were general weakness(11 patients), tingling & numbness of mouth and/or extremities(10 patients), nausea and vomiting(9 patients), dizziness(9 patients), dyspea(8 patients), palpitation(8 patients), chest discomfort(7 patients), epigastric pain(5 patients) and syncope(1 patients) in order of frequency. All patients developed symptoms of aconitine toxicity within 2 hours of ingestion. The reasons for taking aconitine were neuralgia(9 patients), cerebrovascular accident(2 patients), and accidental(1 patient). All patient showed cardiac arrhythmias. The arryhthmias were ventricular premature beat(10 patients), atrial premature beat(6 patients), paroxysmal atrial tachycardia(2 patients), first degree A-V block(3 patients), A-V dissociation(2 patients), atrial fibrillation(1 patient), ventricular tachycardial(1 patient), nonsustained ventricular tachycardia(1 patient), complete RBBB(1 patient), and incomplete LBBB(1 patient). The arrhythmias were coverted to normal sinurs rhythm in all 10 admitted patients until discharge. Eight patient represented hypotension. But with conservative management, all patients were recovered from hypotension. There was no fatal case, but one patient was identified with feature of myocardial ischemia as a sequale. conclusion : Aconitum species can cause cardiovascular collapse and serious ventricular arrhythmias. In-hospital observation with ECG monitioring and supportive management should be done until the patient shows normal sinus rhythm and stable blood pressure. the medical profession and general public should be alerted to the potential toxicity of these herbs and their usage should be controlled by regislation.

3극관형 진공게이지 제작 및 최적조건 결정

박래준,배정운,박종윤 성균관대학교 기초과학연구소 1996 論文集 Vol.47 No.2

B-A type hot cathode ionization gauge to measure the UHV(Ultra High Vacuum) was generally used in these days. Whereas, HV(High Vacuum) is still major pressure region in the application of vacuum to the industry. Conventional triode gauge(CTG) is used mainly for measurement in HV region, thus we constructed the modified triode gauge(MTG). In order to find the optimum condition of MTG. We measured I_e vs U_c, I_e vs U_g and U_c, I_e vs U_g and P, I_i vs U_g and P as well as I_i vs P because I_i is depend on pressure(P), filament potential(U_c), grid potential(U_g), filament heating power(Hp), and emission current(I_e). The good linearity of I_i P curve is obtained from ∼10^-6 to ∼10^-4 torr at 5A heating current, 200V grid potential, 40V filament potential and below ∼10^-7 torn at 4.6A.

급성 심근 경색증에서 혈전 용해술이 Residual Ischemia와 Cardiac Event에 미치는 영향

이준희,김경래 대한응급의학회 1995 대한응급의학회지 Vol.6 No.1

Background : Thrombolytic therapy was known as first treatment of choice in patients with acute myocardial infarction(AMI). This study was designed to assess the effect on residual is chemia and cardiac event (postinfarct angina, recurrent myocardial infarction, cardiac death) after thrombolytic therapy for AMI. Method and Results : We reviewed 42 patients, admitted with AMI during three years from January 1991 to December 1993. all patients performed treadmill test or thallium scintigraphy and had out-patient follow-up checking over one year. Twenty one patients were recieved by thrombolytic therapy (Group A) and the remaining twenty one patients were not (Group B). Mean age was 58±8 years in group A and 60±11 years in group B. Residual ischemia was reduced by thrombolytic therapy, 19% in group A compared with 48% in group B(P<0.05). No significant differences in incidence of cardiac event were found between the two groups(19% and 19%). Conclusion : Thrombolytic therapy reduced the residual ischemia after AMI but did not reduced the incidence of cardiac event in long term follow-up.

심폐소생술시에 호기말 이산화탄소 분압 측정의 이용

이준희,안성태,김경래 대한응급의학회 1995 대한응급의학회지 Vol.6 No.1

The effectiveness of ongoing cardiopulmonary resuscitation (CPR) efforts is difficult to evaluate. During a cardiac arrest and attempted resuscitation, there are no readily available noninvasive measurements that identify patients who are likely to have return of spontaneous circulation (ROSC). A number of studies in animals and humans suggest that systemic perfusion during arrest and CPR is related to the end-tidal volume of carbon dioxide, which is an indirect measure of pulmonary perfusion. A clinical study was done to determine whether endtidal carbon dioxide (PetCo₂) monitoring during CPR could be used as a prognostic useful noninvasive indicator of resuscitation and survival. The concentration of expired carbon dioxide was measured continuously with caphnography-BCI Model 9000 Caphnographer/Oximeter (Biochemical International, Inc., Waukesha, WI). to evaluate its clinical applicability, we performed prospective, bedside measurements of the PetCO₂in patients after cardiac arrest and during CPR. We measured the PetCO₂during 20 episodes of adult nontraumatic cardiac arrest and resuscitation in 16 critically ill patients during December, 1994 through February, 1995. Spontaneous circulation was restored in eight victims(40%). The mean PetCO₂of successfuly resuscitated group (ROSC, N=8, 23.6±5.5 mmHg) was higher than that of non-resuscitated group (non-ROSC, N=12, 8.7±3.0 mmHg) (p<0.05). the three patients survived more than 24 hours had a higher mean PetCO₂than that of the 17 patients survived less than 24 hours(28.0±6.0 vs 12.3±6.5 mmHg) (p<0.05). All eight patient who were successfully resuscitated had a PetCO₂of 15 mmHg or greater. No patient with a PetCO₂of less than 15 mmHg was resuscitated. We concluded PetCO₂monitoring during CPR are correlated with resuscitation from cardiac arrest. We also propose that measurement of the PetCO₂may be a practical and noninvasive method for monitoring blood flow generated by precordial compression during CPR, and may be an almost immediate indicator of successful resuscitation.

간문부 담관암 환자에서 경피경관 양측성 금속 배액관의 효과

김금래,김주형,박원규,장재천,조재호,김태년,김준화,장병익 영남대학교 의과대학 2005 Yeungnam University Journal of Medicine Vol.22 No.2

Background: The purpose of this study was to determine the effectiveness of percutaneously place self-expanding metallic stent for the relief of biliary obstruction in patients with hilar cholangiocarcinoma. Materials and Methods: From November 2001 to December 2004, 48 patients with hilar cholangiocarcinoma were prospectively studied. After percutaneous placement of bilateral self-expanding, uncovered metallic stents, follow-up evaluation was carried out until July 2005. Results: There were 4 cased of Bismuth type Ⅱ,21 cases of Bismuth typeⅢa 8 cases of Bismuth type Ⅲb and 15 cases of Bismuth type Ⅳ. Stent placement was technically successful in all patients All patients had satisfactory biliary drainage, resulting in one week drainage rate of 72.8% and final drainage of 91.9% There were 12 cases (21.3%) of abdominal pain requiring analgesics and 1 case (7.1%) of cholangitis; both were successfully managed with conservative treatments. Late complications occurred in four patient (8.3%), including two patients with cholangitis, one patient with liver abscess, and one patient with biloma; all were appropriately managed by percutaneous drainage. The average length and median durations of stent patency and median survival time were 303 days (range, 60~815) and 338 days (range, 60 ~1175), respectively. Conclusion: Placement of a percutaneous metallic stent is an effective and safe method of palliation of patients with hilar cholangiocarcinoma.

구강외과 환자의 전신마취관리

이준례 全北大學校 齒醫學硏究所 1984 전북치대논문집 Vol.2 No.1

201 patients who underwent surgical operation at the Department of oral surgery, school of Dentistry, Chon-buk National University from January 1983 to December 1984 were analyzed statistically according to age, sex, disease, endotracheal intubation and anesthetic technique. The results were as follows ; 1. The most frequent age group was in the 3rd decade(29%), and sex distribution was male (78%) and female(22%). 2. Of the total 201 operations, open reduction of maxillofacial bone fracture was 131 cases, cheiloplasty and palatorrhaphy 27 cases, benign and malignant tumor surgery 10 cases, orthognathic surgery 6 cases, osteomyelitis 4 cases. Caldwell-Luc operation 19 cases and radical neck dissection 3 cases, bone graft 1 cases. 3. The nasotracheal intubation and orotracheal intubation were performed in 179 cases and 25 cases respectively. In 6 cases, tracheostomy was done because of the difficulty in endotracheal intubation. 4. For anesthesia of the patients the semiclosed circle system was practiced using mainly halothane-O_2-N_2O and pancuronium as muscle relaxant in adults. Jackson-Rees technique using halothane-O_2-N_2Owithout muscle relaxant was used in children.