석탄 가스화를 통한 전력 생산과 DME 병산 공정에 대한 기초 경제성 분석

유영돈 ( Young Don Yoo ),김수현 ( Su Hyun Kim ),조원준 ( Won Jun Cho ),모용기 ( Yong Gi Mo ),송용택 ( Tae Kyong Song ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.6

석탄가스화를 기반으로 한 발전(IGCC 발전) 및 화학원료 제조공정의 상업화 관건은 화석연료인 원유 또는 천연가스를 기반으로 생산되는 경우와 비교하여 경제성을 확보할 수 있는지 여부이다. 경제성 확보를 위한 가장 현실적인 방법으로는 석탄 가스화를 통해 얻어진 합성가스로부터 2개 이상의 생산물(예: 발전과 화학원료를 동시 생산)을 병산(coproduction또는 poly-generation)하는 것이다. 본 연구에서는 석탄 가스화를 기반으로 하여 발전과 수송용, 발전용 및 가정용 연료로 사용이 가능한 DME(dimethyl ether)를 병산하는 공정에 대한 경제성 분석을 실시하였다. 경제성 분석을 위한 병산 공정에서는 250 MW 전력생산 연간 30만 톤의 DMZ 생산을 기준으로 하였다. 병산 공정에서 DME 판매가격이 50만원/ton인 경우, 전기 생산원가는 34.8~58.4원/kWh으로 SMP(계통한계가격) 가중평균인 150.69원/kwh(2013년 1월~12월까지의 평균값)의 33~58% 수준으로 산정되었다. 따라서, DME 판매가격이 적정하게 유지될 경우 석탄IGCC+DME 병산공정은 IGCC 단독 발전과 비교하여 경제성을 확보할 수 있을 것으로 판단된다. 현재 중국에서 DME판매가격이 900,000원/톤 내외이므로, 전력과 DME를 병산할 경우, IGCC 단독으로 전력을 생산할 경우와 비교하여 전력 생산 원가를 월등하게 낮출 수 있음을 알 수 있다. 이와 같이 석탄 가스화를 기반으로 한 병산 공정을 통해 전력과 DME를 병산하는 시스템에서, 시장 여건에 따라 전력과 DME 생산비율 제어가 가능하고, 석탄 가스화기 및 정제 시스템을 공통 설비로 활용함으로써, 개별적으로 생산하는 것보다 생산 원가를 낮출 수 있다는 결과를 얻었다. The key for the commercial deployment of IGCC power plants or chemical (methanol, dimethyl ether, etc.) production plants based on coal gasification is their economic advantage over plants producing electricity or chemicals from crude oil or natural gas. The better economy of coal gasification based plants can be obtained by co-production of electricity and chemicals. In this study, we carried out the economic feasibility analysis on the process of co-producing electricity and DME (dimethyl ether) using coal gasification. The plant’s capacity was 250 MW electric and DME production of 300,000 ton per year. Assuming that the sales price of DME is 500,000 won/ton, the production cost of electricity is in the range of 33~58% of 150.69 won/kwh which is the average of SMP (system marginal price) in 2013, Korea. At present, the sales price of DME in China is approximately 900,000 won/ton. Therefore, there are more potential for lowering the price of co-produced electricity when comparing that from IGCC only. Since the co-production system can not only use the coal gasifier and the gas purification process as a common facility but also can control production rates of electricity and DME depending on the market demand, the production cost of electricity and DME can be significantly reduced compared to the process of producing electricity or DME separately.

초음파 가이드를 통한 맥락막상강출혈의 치료

이기헌,유재호,김태원,이상준,김신동 고신대학교 의과대학 2009 고신대학교 의과대학 학술지 Vol.24 No.1

Purpose : Intraoperative suprachoroidal hemorrhage is one of the most serious complications. We report a case of suprachoroidal hemorrhage during phacoemulsification surgery, was managed properly. Methods : Suprachoroidal hemorrhage occurred during phacoemulsificaiton in other hospital. The patient was referred to our department immediately after closing the surgical wound. On initial examination, iris and vitreous were prolapsed through surgical wound. Ciliary body was closely place to anterior chamber, and retina was not visible. Results : Prolapased ocular tissue were reduced by emergency operation. We controlled the patient’s intraocular pressure and inflammation. Ultrasonography was repeatedly performed to check the degree of liquefaction of suprachoroidal hemorrhage. After 9 days of suprachoroidal hemorrhage onset, vitrectomy and drainage through sclera was performed. Postoperative state was stable with successful removal of suprachoroidal hemorrhage. After 2 weeks of secondary operation, retinal detachment has occurred on nasal retinal area, so we performed scleral buckling and endolaser photocoagulation. After 6 months, retina was attached well and intraocular pressure was in normal range. Conclusion : In suprachoroidal hemorrhage, drainage of suprachoroidal hemorrhage after liquefaction of thrombi is effective. After successful drainage, postoperative complications may accompany such as retinal detachment or elevation of intraocular pressure. 목적 : 술중 발생하는 맥락막상 출혈은 매우 심각한 합병증이다. 저자는 수정체 유화술 중에 발생한 맥락막상 출혈을 적절히 대처한 증례를 보고하는 바이다. 대상과 방법 : 수정체 유화술 중 발생한 맥락막상강 출혈환자가 수술창을 봉합 후 즉시 본원으로 전원되었다. 초진시 홍채와 유리체가 수술창을 통해 탈출되어 있었으며, 전방을 통해 모양체가 확인되었으나, 망막은 보이지 않았다. 탈출된 안구내 조직을 응급수술을 통해 복원 후 환자의 안압과 염증을 조절하였다. 초음파를 반복적으로 실시하여 맥락막상 출혈의 액화 정도를 확인하였으며, 출혈 9일 후 유리체 절제술과 공막을 통한 배액술을 시행하였다. 결과 : 맥락막상 출혈이 성공적으로 제거되었으며 술 후 상태는 안정적이었다. 수술 2주 후 비측 망막 박리가 발생하여 공막돌륭술과 안구내 삽관 레이저술을 시행하였다. 6개월 후 망막은 잘 붙어있었으며, 안압은 정상 범위를 유지하였다. 결론 : 맥락막상 출혈의 경우 출혈의 배액 시기를 결정하는 것이 어렵지만, 규칙적인 초음파를 통해 배액술의 시기를 결정할 수 있다. 또한 맥락막상강 출혈의 성공적인 배액 이후에도 망막박리 및 안압상승과 같은 합병증의 동반에 대해 유념해야한다.

치과병원에서 사용되는 진단영상에 대한 JPEG 2000 압축률에 대한 평가

정기훈,한원정,유동수,최순철,김은경 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Purpose : To find out the proper compression ratios without degrading image quality and affecting lesion detectability on diagnostic images used in dentistry compressed with JPEG 2000 algorithm. Materials and Methods : Sixty Digora periapical images, sixty panoramic computed radiographic (CR) images, sixty computed tomographic (CT) images, and sixty magnetic resonance (MR) images were compressed into JPEG 2000 with ratios of 10 levels from 5 : 1 to 50 : 1. To evaluate the lesion detectability, the images were graded with 5 levels (1: definitely absent; 2: probably absent; 3: equivocal; 4: probably present; 5: definitely present), and then receiver operating characteristic analysis was performed using the original image as a gold standard. Also to evaluate subjectively the image quality, the images were graded with 5 levels (1: definitely unacceptable; 2: probably unacceptable; 3: equivocal; 4: probably acceptable; 5: definitely acceptable), and then paired t-test was performed. Results : In Digora, CR panoramic and CT images, compressed images up to ratios of 15 : 1 showed nearly the same lesion detectability as original images, and in MR images, compressed images did up to ratios of 25 : 1. In Digora and CR panoramic images, compressed images up to ratios of 5 : 1 showed little difference between the original and reconstructed images in subjective assessment of image quality. In CT images, compressed images did up to ratios of 10 : 1 and in MR images up to ratios of 15 : 1. Conclusion : We considered compression ratios up to 5 : 1 in Digora and CR panoramic images, up to 10 : 1 in CT images, up to 15 : 1 in MR images as clinically applicable compression ratios.

활동혈압에 의한 Cicletanine의 강압효과 판정

정태기,김현대,류재춘,최석구,유원상 인제대학교 1993 仁濟醫學 Vol.14 No.4

Prostaglandin 합성을 촉진하는 새로운 강압약인 cicletanine의 강압효과를 진료실 혈압과 24시간 활동혈압으로 평가했을 때 상당한 차이를 보여 그 이유를 검토해 보았다. To evaluate antihypertensive effect of cicletanine with both clinic and ambulatory blood pressure monitoring, 10 male hypertensive patients were administered cicletanine, a new antihypertensive stimulating prostaglandin synthesis, in 100∼200 mg daily for 12 weeks. The following were the results. 1.Mean of clinic BP decreased from 161/98 mmHg to 153/98 mmHg. 2.Mean of ambulatory BP changed from 140/91 mmHg to 153/99 mmHg. 3.Side reactions were mild, namely indigestion and constipation. 4.Discrepancy between clinic and ambulatory BP were discussed. In conclusion cicletanine revealed slight antihypertensive effect with clinic blood pressure, but failed to confirm it with ambulatory blood pressure.

항결핵 치료과정에서 호전되었다가 악화된 뇌 결핵종 1예 보고

이대훈,유진홍,강미자,김홍기,김선화,고동훈,천지성,유원종 대한화학요법학회 1997 대한화학요법학회지 Vol.15 No.3

In spite of nationmide tuberculosis control program, tuberculosis is still prevalent in Korea. Accordingly, tuberculous meningitis also poses one of the main trouble some problems. Recently, We experienced a perplexing case of tuberculous menin-gitis and tubercdoma in a 24-year old female patient. She was admitted to our hospital owing to meningeal irritation sign, aphasia, VI nerve palsy, and ,fever. CSF analysis showed a finding consistent with that of presumptive tuberculous meningitis.. Initial MRI of the brain revealed a large mass(tuhercu1oma) on left parieto-temporal area. Antitubeculous regimen(1soniazid (INH), rifampin(RMP), ethambutol(EMB), pyrazinamide(PZA)} of meningeal dose was given immediately, and her symptoms and signs were dramatically disappeared with a few days after treatment. She was discharged with improved condition and under maintenance treatment of tuberculosis. Follow-up one year after treatment. revealed that the previous lesion was nearly diminished. She showed no symptom at all until she recognized a total blindness of sudden onset on her left eye a t the 18th month of treatment. Brain MRI checked at that time showed multiple masses of tuberculoma scattered over the brain base and one of them invaded left optic nerve. In our opinion, the cause of relapse in this patient might he explained by the selection and ultimate replication of a minor population of resistant strain. Although such relapse is an extremely rare event, we think that we should always pay attention to this possible resistance problem every time we meet patients with tuberculous meningitis.

만성 심부전 환자에서의 Denopamine 투여효과

최석구,김현대,정태기,김대현,김용복,유원상 인제대학교 1994 仁濟醫學 Vol.15 No.2

만성 심부전 환자에게 새로운 경구용 비 digitalis 강심제인 denopamine 1T(5mg)을 1일 3회 3개월간 투여하여 그 유효성 및 안전성을 검토했다. Background : Patients with congestive heart failure have a high mortality rate and are also hospitalized frequently. We studied the effects of a new oral inotrophic agent, denopamine in patients with chronic heart failure. Methods : 16 patients receiving conventional treatments for heart failure were treat ed with denopamine 5mg tad for at shortest 3 months. Their history were taken and the physical examination, general laboratory test and the echocardiographic examination were done before and after treatment. Results: There were 3 deaths and 1 withdrawal because of worsening heart failure. 5 patients (42%) among 12 patients showed the improvement in their subjective symptoms. The fractional shortening and ejection fraction of the left ventricle were increased by 3.2% and 5.6% respectively in their absolute values. Conclusion : The addition of denopamine to conventional therapy considerably improved the subjective symptoms and the left ventricular function in the limited number of patients with chronic heart failure.

The Effect of Surface Coating on LiNi_0.6Co_0.1Mn_0.3O₂ Cathode Material for Lithium Secondary Battery by PEDOT-PEG Block Copolymer

Yoo, Gi-Won,Jang, Byeong-Chan,Kim, Cheong,Son, Jong-Tae American Scientific Publishers 2017 Science Of Advanced Materials Vol.9 No.5

Effect of Structural and Electrochemical Properties of Yttrium-doped LiNi0.90Co0.05Al0.05O2 Electrode by Co-precipitation for Lithium Ion-batteries

Yoo, Gi-Won,Tae-Jun Park, Tae-Jun,Son, Jong-Tae Journal of New Materials for Electrochemical Syste 2015 JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTE Vol.18 No.1

<P>In this study, the LiNi0.90−xCo0.05Al0.05YxO2 (x = 0, 0.025, 0.075) have been synthesized by a co-precipitation and solid-state reaction method. The effect of the Y3+-doping on the structural and electrochemical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and by electrochemical and impedance spectroscopy (EIS). From the results of the XRD pattern changes between before and after the doping, less cation mixing and more ordered hexagonal structure were observed for the LiNi0.875Co0.05Al0.05Y0.025O2 cathode and the cell delivered an initial discharge capacity of 195.8 mAhg-1 and was 10.2 mAhg-1 higher than the pristine cell by yttrium doping effect. High rate capability studies were also performed and showed the capacity retention of 95, 81.7 and 63.8 % at 0.2, 1.0 and 5.0 C-rate, respectively during the cycling. The impedance spectra showed that the charge transfer resistance for the pristine cathode grew significantly, while that for the Y3+-doped cathode decreased during cycling. It was concluded that the capacity fading for LiNi0.90Co0.05Al0.05O2 mainly due to the cation mixing, partially contributed by the impedance growth and by doping the pristine material with Y3+, cation mixing can be efficiently suppressed, which results in the improved rate capability.</P>

Porous supraparticles of LiFePO₄ nanorods with carbon for high rate Li-ion batteries

Yoo, Jong Won,Zhang, Kan,Patil, Virendra,Lee, Jeong Taik,Jung, Dae-Woong,Pu, Lyong Sun,Oh, Woong,Yoon, Won-Sub,Park, Jong Hyeok,Yi, Gi-Ra American Scientific Publishers 2018 Materials express Vol.8 No.4

Synthesis of Hollow Nanorods of SiO₂ Anode Material by AAO Template Synthesis Method for Lithium Ion Battery

Yoo, Gi-Won,Kim, Cheong,Jang, Byeong-Chan,Yang, Su-Bin,Son, Jong-Tae American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.11