솔-젤법에 의한 Nb_2O_5-Fe_2O_3 혼합산화물의 제조 및 산 특성조사

정석조,양희정,권재범,이내우,우희철 釜慶大學校 2000 釜慶大學校 論文集 Vol.5 No.-

In this study, some of results from a study conducted on the preparation of niobium coated hematite particles to be used as a catalyst are presented.α-Fe_2O_3 (hematite) particles obtained by aging an acidic solution of ferric(Ⅲ) ions at high temperature were first prepared as core particles and synthesised by hydrolysis at high temperature with layers of amorphous niobium pentaoxide (Nb_2O_5) deposited by the hydrolysis of niobium pentachloride. The effects of varying molecular ratio of Nb/Fe (10/1, 5/1, 1/2, 1/5, 1/10) were studied. The synthesised particles were characterized for their physical and chemical properties using XRD, SEM, TPD, BET etc. The process of the surface coating showed heterocoagulation rather than surface nucleation and growth. A preliminary investigation of the acidic characterization and specific surface area of the synthesised particles showed that these particles can achieve an acidic characteristic changed and enhanced specific surface area of that of pure niobia and α-Fe_2O_3 prepared here.

산업용 보일러 배기가스 중의 NO_x 제거를 위한 TiO_2 담지 산화 중석 촉매들의 내열성과 그 촉매표면 산성특성과의 상관관계

丁碩鎭,李重範 慶熙大學校 1989 論文集 Vol.18 No.-

In order to suggest an efficient catalyst systems for the NOx reduction of flue gases from industrial boilers, TiO_2 supported WO_3, WO_3-V_2O_5, V_2O_5 and WS_2 catalysts were tested for the performances of NOx reduction at high reaction temperature range (250-500℃) using a simulated flue gas system. It was found that while the proposed WO_3/TiO_2 and V_2O_5-WO_3/TiO_2 catalysts showed a significant high NOx reduction efficiencies at about 350-400℃, the conventional commercial catalyst of V_2O_5/TiO_2 showed a significant drop in NOx reduction efficiency due to the excessive NH_3 oxidation. From the measurements of surface acidities of those catalysts, it was found that the acidities are well correlated with the activities of NOx reduction. The reason of high activity of WO_3 series catalysts at high reaction temperature seems due to the low value of surface excess oxygen compared with that of V_2O_5/TiO_2 catalyst. The active site for NOx reduction of WO_3/TiO_2 seems equivalent to the acid site of that catalyst.

조기유자망 어구의 개량 및 생력화 조업시스템 개발 : 3. 생력형 5단 양망기의 해상 성능 시험

김석종,구명성,강경범,서대범,정용진 제주대학교 해양과환경연구소 2005 해양과환경연구소 연구논문집 Vol.29 No.2

인공 황산비 및 질산비가 애기장대의 생장과 종자발아에 미치는 영향

이석찬,박정안,박종범 한국환경과학회 2003 한국환경과학회지 Vol.12 No.6

The experiment was carried out to investigate the effects of sulfuric acid and nitric acid among the main components of simulated acid rain (SAR) on the growth of vegetative organs and seed germination of Arabidopsis thaliana. The Arabidopsis treated with SAR supplemented with sulfuric and nitric acids, respectively, showed 28% and 30% decrease of shoot and root growth compared to the control plants, and also many necrotic spots on leaf surfaces after SAR treatment were observed. The shoot and root length for plants grown with nitric acid rain was 14% and 17% lower, respectively, compared to the control, whereas those grown with sulfuric acid rain was 24% and 25% lower than control plants. When Arabidopsis seeds were sown in distilled water, germination rate was 100% after 7 days. However, 80% in SAR medium supplemented with sulfuric and nitric acids, 88% in sulfuric acid rain medium and 93% in nitric acid rain medium. The germination abilities of seeds harvested from SAR supplemented with sulfuric and nitric acids, sulfuric acid rain, and nitric acid rain were 73%, 73% and 94%, respectively. Consequently, sulfuric acids showed more inhibitory effects than nitric acids on the growth of vegetative organs as well as germination rates in Arabidopsis.

노인환자에서 전신마취 후 발견된 뇌경색

이광범,김정률,안용미,최준석,박천희 朝鮮大學校 附設 醫學硏究所 2008 The Medical Journal of Chosun University Vol.33 No.3

Perioperative cerebral infarction is rare but may be fatal. This is a case report of acute cerebral infarction following general anesthesia in geriatric patient. A 72 year old female patient was admitted for transabdominal hysterectomy and bilateral saipingooophorectomy and pelvic lymphnode dissection. Preanesthetic assessment revealed a history of hypertension and diabetes mellitus. After surgery, she was alert but she gradually appeared to have right hemiparesis and confusion. Emergency CT brain scan showed early cerebral infarction in the middle cerebral artery territory. She was transferred to the depart ment of neurology and received treatment. She was discharged at 19 days after surgery with improved symptoms.

유전적 알고리즘을 이용한 근거리 통신망의 위상 설계

조정복,임효택,이재욱,고석범 東西大學校 1999 동서논문집 Vol.5 No.-

최근에 많은 기업체에서 네트워크 설계 분야에 많은 관심이 집중되고 있다. 본 논문에서 Star-Ring LAN(Local Area Network)상에서 허브(HUB)의 할당과 경로 선택 문제를 취급한다. Star-Ring LAN의 설계는 1)허브들과 사용자 노드 즉, 컴퓨터들간의 연결,2)허브들간의 경로 선택 문제로 나눌 수 있다. 여기서 제안한 수학적 모델은 허브의 설치 비용과 각 노드에서 트래픽의 전송 지연 시간을 고려한다. 그리고, 최적 해를 탐색하기 위하여 경험적 탐색 방법의 하나인 유전 알고리즘(GA:Genetic Algorithm)을 설계한다. 끝으로 본 논문에서 제안된 유전 알고리즘의 성능을 검증하기 위하여 하나의 수치 예를 보인다. Recently, many people are interested in the field of network design again as we know that Intranet environment based on LAN(Local Area Network) is often implemented at many companies. In this paper, we deal with HUB allocation and routing problem on Star-Ring LAN. The design of Star-Ring LAN is divided into two level problems; 1) connecting between HUBs and user nodes(i.e,computers), and 2) routing between HUBs, and delay time due to communication traffic at each node should be considered as the important factors. Also, we investigate GA(genetic Algorithm) as heuristic method to search the optimal solution. Lastly we suow a numerical example to demonstrate good performances of tje proposed method.

흰쥐에서 반복적 스트레스가 신경활성 스테로이드의 GABAA 수용체 조절작용에 미치는 영향

장봉석,이종범,박형배,하정희,송창진 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.3

연 구 : 신경활성 스테로이드는 대뇌피질 세포막의 GABAA 수용체 복합체에서 GABAA 수용체 효현제 양상으로 작용하여 [³H]flunitrazepam이 GABAA 수용체에 결합하는 항진 작용이 관찰되었으나, 반복적으로 신경활성 스테로이드를 처치한 세포에서는 이러한 신경활성 스테로이드의 [³H]flunitrazepam 결합 항진효과가 소실되었다는 보고가 있었다. 이에 본 연구에서는 반복적인 스트레스에 부하된 흰쥐를 사용하여 신경활성 스테로이드의 GABAA 수용체에 대한 배위자(ligand)의 결합반응 양상을 정상 실험동물과 비교, 관찰하여 보고자 하였다. 방 법 : 본 연구에서, 벤조다이아제핀 수용체 결합반응(receptor binding assay)을 위한 [3H]flunitrazepam 결합반응을 위해서는 GF/B 여과지(Whatman) 상에서 Brandel M-24R을 사용하여 측정했고, GABAA 수용체 결합반응 (receptor binding assay)을 위한 [3H]muscimol 결합반응에서는 각 시험관 당 100㎕의 대뇌피질 조직(약 0.32mg 단백에 해당)을 사용하였으며, 상기 벤조다이아제핀 수용체 결합반응과 동일한 실험방법을 실시하였다. 결 과 : 신경활성 스테로이드인 pregnanolone은 대뇌피질 세포막의GABAA수용체 복합체에 대한 [³H]flunitrazepam 결합반응을 항진시켜 GABAA 수용체 효현제 양상으로 작용하는 것으로 관찰되었다. 또 pregnanolone이 GABAA 수용체 복합체상의 GABA 결합부위에 대한 결합력을 알아보기 위하여 GABAA 수용체 효현제인 [³H]muscimol 결합반응을 실시하였을 때 pregnanolone은 50%정도의 억제율을 보여주는 GABA와는 그 결과가 다르게 [³H]muscimol 결합반응을 억제하지 않음으로써. muscimol과 경쟁적으로 같은 결합부위에 작용하지 않는다는 것을 보여주었다. 또 반복적인 부동화 스트레스에 부하된 흰쥐의 대뇌 피질조직을 사용하여 pregnanolone의 [³H]flunitrazepam 결합반응을 관찰하였을 때, 대조군에 비하여 pregnanolone의 [³H]flunitrazepam 결합 항진작용이 감약되는 것을 관찰하였다. 결 론 : 이상의 결과로부터 반복적인 스트레스에 부하된 흰쥐의 대뇌피질조직에서는 정상 흰쥐에 비하여, pregnanolone이 GABA성 신경전달에 미치는 항진작용이 감약되었으며, 이는 반복적인 스트레스와 연관된 불안장애의 정신생리 규명에 중요한 정보라고 사료된다. Objectives : Pregnanolone is a potent positive modulator of the γ-aminobutyric acid(GABA) response that enhances the binding of [³H]flunitrazepam to the GABAA receptor. Recently, it was reported that chronic treatment with pregnanolone uncouples allosteric interactions between steroid and benzodiazepine recognition sites. The present study was designed to assess the effect of repeated stress on the modulation of neuroactive steroids on the GABAA receptor. Methods : The effect of steroids on the ligands binding to GABAA receptor was investigated using cerebral cortices of unstressed and repeatedly immobilized rats. Male Sprague-Dawley rats, weighing 200-250g were forced to suffer an immobilization stress for 2 hours. Results : Pregnanolone enhanced the binding of [³H]flunitrazepam to GABAA receptor in both of unstressed and repeatedly stressed rats. However, repeatedly stressed rats showed significantly higher values in EC50 and lower values in Emax of enhancement binding of [³H]flunitrazepam than those of unstressed rats. Conclusions : From these findings, it can be concluded that repeated stress reduced the positive modulation of neuroactive steroid no the GABAA-receptor complex.

공동주택의 에너지 절약 및 공기환경개선을 위한 열교환기의 성능평가

김범석,정용호,박병윤,손장열 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

This study was aimed to suggest the appropriate residential heat and moisture recovery ventilation systems(HRVs) in order to maintain an acceptable indoor air quality for the climatic conditions of Korea. This study was developed from experimental data on HRV Performance specifications and HVAC system. Results show that total heat exchangers of rotary type is applied on HVAC system that is possible to conserve energy and improve indoor air quality.

데이타 네트워크에 있어서 경로 선택 알고리즘에 관한 연구

조정복,이재욱,임효택,고석범 東西大學校 1998 동서논문집 Vol.4 No.-

최근에 많은 기업체에서 LAN(Local Area Network)을 기반으로 하는 인터넷 환경을 구축하는 예가 종종 보고되어 지는 것을 보면 네트워크 설계분야에 많은 관심이 집중되고 있음을 알 수 있다. 본 논문에서, Star-Ring LAN상에서 HUB의 할당과 경로 선택 문제를 취급한다. Star-Ring LAN의 설계는 1)HUB들과 사용자 노드(컴퓨터)들 간의 연결, 2)HUB들 간의 경로 선택 문제로 나눌 수 있다. 여기서 제안한 수학적 모델은 HUB의 설치 비용과 각 노드에서 트래픽의 전송 지연 시간을 고려한다. 그리고 최적 해를 탐색하기 위하여 경험적 탐색방법의 하나인 유전 알고리즘(GA:Genetic Algorithm)을 설계한다. 끝으로 본 논문에서 제안된 유전 알고리즘의 성능을 검증하기 위하여 하나의 수치 예를 보인다. Recently, many people are interested in the field of network design again as we know that Intranet environment based on LAN(Local Area Network) is often implemented at many companies. In this paper, we deal with the HUB allocation and routing problem on Star-Ring LAN. The design of Star-Ring LAN is divided into two level problems: 1)connecting between HUBs and user nodes(i.e. computers), and 2) routing between HUBs. In the mathematical model which we will develope, the cost to set up HUBs, and delay time due to communication traffic at each node should be considered as the important factors. Also, we investigate GA(genetic Algorithm)as heuristic method to search the optimal solution. Lastly, we show a numerical example to demonstrate good performances of the proposed method.

Thermus caldophius GK24로부터 DNA Iigase 유전자의 클로닝 및 발현

김현규,이정범,정승은,권석태 성균관대학교 생명과학자원연구소 1996 生命資源科學硏究 Vol.3 No.2

Thermostable DNA ligase is an essential enzyme for the ligase chain reaction(LCR), a method of detection of a single point mutation. Firstly reported thermostable DNA ligase gene was Tth lig gene of Thermus thermophilus HB8 in 1991. We amplified a new thermostable DNA ligase gene of Thermous caldophilus GK24 using the method of PCR. Used degenerate primers DLI and DLT were designed based on Tth DNA ligase gene. This amplified Tca DNA ligase gene was cloned and expressed. For DNA subcloning and sequencing, restriction enzyme sites of the gene were analyzed.