Improvement of Desulfurization Efficiency via Numerical Simulation Analysis of Transport Phenomena of Kanbara Reactor Process

Yong‑Joon Lee,Kyung‑Woo Yi 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.4

The Kanbara reactor (KR) process is a mechanical stirring method that reacts hot metal with desulfurization flux; it is a widelyimplemented desulfurization method in contemporary steel production. This study aimed to develop a new impeller profilefor improving the desulfurization efficiency of the KR process. We implemented operational data analysis, a computationalfluid dynamics simulation based on the operational data and performed testing and analysis with impeller models on-site aproduction facility. Operational data from the production facility was gathered over a 3-year period. Seven impeller modelswith varying impeller blade width (top and bottom), height, inclination, and curvature (curved, straight, and combination)were simulated. The results were analyzed to determine the optimal conditions. A new impeller design was selected for onsiteoperational testing to investigate the in situ desulfurization efficiency over 350 charges, and the results corroborated thepredictions by the numerical simulations. It is expected that the proposed process modification can be successfully used forimproving industrial desulfurization efficiency.

수근관 증후군에서의 무증상성 척골신경병증

문준식,이성수,이지용,한범기,권준범,양현덕,이성익 대한신경과학회 1999 대한신경과학회지 Vol.17 No.2

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Light-extraction efficiency control in AlGaN-based deep-ultraviolet flip-chip light-emitting diodes: a comparison to InGaN-based visible flip-chip light-emitting diodes.

Lee, Keon Hwa,Park, Hyun Jung,Kim, Seung Hwan,Asadirad, Mojtaba,Moon, Yong-Tae,Kwak, Joon Seop,Ryou, Jae-Hyun Optical Society of America 2015 Optics express Vol.23 No.16

<P>We study light-extraction efficiency (LEE) of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) using flip-chip (FC) devices with varied thickness in remaining sapphire substrate by experimental output power measurement and computational methods using 3-dimensional finite-difference time-domain (3D-FDTD) and Monte Carlo ray-tracing simulations. Light-output power of DUV-FCLEDs compared at a current of 20 mA increases with thicker sapphire, showing higher LEE for an LED with 250-관m-thick sapphire by ~39% than that with 100-관m-thick sapphire. In contrast, LEEs of visible FCLEDs show only marginal improvement with increasing sapphire thickness, that is, ~6% improvement for an LED with 250-관m-thick sapphire. 3D-FDTD simulation reveals a mechanism of enhanced light extraction with various sidewall roughness and thickness in sapphire substrates. Ray tracing simulation examines the light propagation behavior of DUV-FCLED structures. The enhanced output power and higher LEE strongly depends on the sidewall roughness of the sapphire substrate rather than thickness itself. The thickness starts playing a role only when the sapphire sidewalls become rough. The roughened surface of sapphire sidewall during chip-separation process is critical for TM-polarized photons from AlGaN quantum wells to escape in lateral directions before they are absorbed by p-GaN and Au-metal. Furthermore, the ray tracing results show a reasonably good agreement with the experimental result of the LEE.</P>

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1998)

김재홍,김준호,반재용,이정우,황성주,정준규,정성태,강진문,조흔정,홍창의,정혜신,이한승,김이선,이봉길,이종호,선영우,한기덕,윤성필,이성훈,안종성,박석범,문승현,조항래,김형섭,류지호,황재영,박준홍,손상욱 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.1

In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria gonorrhoeae(PPNG), we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by menas of the chromogenic cephalosporin method. In 1998, 93 strians of N. genorrhoeae were isolated, among which 60(64.5%) were PPNG. The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 64.5% in 1998.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

SM45C鋼 熔接部의 殘留應力에 依한 疲勞破壞擧動

李龍福,金鍾鉉,金相準 弘益大學校 1987 弘大論叢 Vol.19 No.2

Fatigue fracture behaviors of submerged arc welded SM45C steel were investigated when a crack propagated from tensile residual stress region. The experimental values were compared with the values expected by the Forman equation. The results are summarized as follows: 1. When the fatigue crack was propagated the experimental values were found to corresponded to the values predicted by Formane quation. 2. The experimental values in weld metals have a little difference to the values expected by Forman equation. It was assumed that residual stresses were relaxed by repeated tensile loading. 3. The higher stress ratios were, the larger the difference of fatigue crack growth rate always were in the Same stress intensity factor range for each stress ratios. Particularly, these differences of fatigue crack growth rates were smaller in weld metal than in base metal. It agrees with the fact of that the difference of .effective stress ratios for each stress ratios is small.

한국인에서 다변성 D12S391 유전좌의 집단유전학적 연구

이용욱,김성민,구태완,이혜린,강일호,한길로,이혜승,황적준 大韓法醫學會 1999 대한법의학회지 Vol.23 No.1

The hypervariable short tandem repeat(STR) locus D12S391 was investigated in a Korean population. A total of 14 alleles were detected by size under denaturing conditions in 517 unrelated individuals. To confirm all of the alleles detected in a Korean population, a total of 34 fragments were sequenced. Prior to allele designation, we constructed the allelic ladders containing 11 alleles sequenced in this study. Allele 18 is the most common with a frequency of 0.281 in Koreans, and one variant allele 19.3 which have been confirmed by sequencing, was detected. The observed heterozygosity, the power of discrimination (PD), and the mean exclusion chance (MEC) for the locus D12S392 is 0.781, 0.946 and 0.652 , respectively. No deviation from Hardy-Weinberg equilibrium was observed in a Korean population (p=0.557). In the 424 meioses in 105 Korean families confirmed using other 17 STR loci, no mutation was detected in locus D12S391. The STR locus D12S391system is useful both for the analysis identification and parternity.

경막내 척수 섬유지방성 과오종 치험 1례 - 증 례 보 고 -

이용근,조준,문창택,장상근 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.10

미세혈관 수술후 Urokinase투여효과에 관한 실험적 연구

이세일,오석준,김용성,양경무 大韓成形外科學會 1987 Archives of Plastic Surgery Vol.14 No.1

However, even the most technically perfect anastomosis can neither eliminate the damage which microneedles cause on the vascular endothelium nor foreign body reaction to the suture material. Thrombosis developed at the suture site and regressed if the stimulus for the thrombosis is not severe. Partial thrombosis was inevitable after microvascular anastomosis. Since systemic thrombolytic drugs were used initially in the management of pulmonary emboli, urokinase were also used in prevention of thrombolysis and thrombolysis after microvascular anastomsis. This experimental study includes the effect of urokinase on the microvascular anastomosis in rabbits. The patency was observed, and platelet count, fibinogen, prothrombin time, and activated partial thromboplastim time were examined. In the case of thromboses, the anastomotic sites were resected and examined microscopically. The results were as follow; 1. The patency rate was increased 15 percent in experimental group than control group. 2. There were no differences in platelet count and the prothrombine time between experimental and control group. 3. The level of fibrinogen was decreased 157㎎/dl in experimental group less than control group. 4. The activated partial thromboplastin time was increased three to four times at postoperative period more than preoperative period in experimental group. 5. In light microscopic examination of thrombotic vessel wall revealed inflammatory reaction to suture material. In the experimental group, the thrombi were loose and defibrinated than control group.