304L 오스테나이트 스테인레스강 분말의 소결성에 미치는 Mo의 첨가 영향

최국선,이동희,최왕규 연세대학교 산업기술연구소 1989 논문집 Vol.21 No.2

An investigation of Mo addition effect on the sinterability of 304L austenitic stainless steel powders was carried out by using the compacts of three different Mo contents(0.2 and 5 wt%) and using diffusion couple of same stainless steel and Mo powders. The compacts of pure stainless steel powder showed conventional sintering process. And also. we found the diffusion (alloying) layer, 60㎛, and porosity formation toward stainless steel compact in the vicinity of coupled zone by means of SEM and EDS analysis. The porosity of compacts to which Mo was added, was high compared with no Mo added compacts except early stage of sintering. But in compacts sintered at 1200℃ for 45 min, the abnormal increase of porosity could be understood by "bridging" effect of alloying layer formed during sintering process.

fac-Tris(L-serinato)chromium(Ⅲ) 화합물의 분광학적 연구 및 리간드장 분석

최영근,서정선,이규왕 명지대학교 자연과학연구소 1995 자연과학논문집 Vol.12 No.-

중심금속chromium(III)와 리간드인.amino acid(L-serine)[serine=HOCH₂CH(NH₂)CO₂H]사이의 결합의 특성을 파악하기 위하여 저온(13K)에서의 luminescence 스펙트럼과 excitation 스펙트럼을 측정하였다.Tris (L-serinato)chromium(III)착화합물은 산소 원자 3개와 질소원자 3개로 이루어진 facial 형태의 geometry를 가진 착화합물이다.Amino acid 를 리간드로 가진 다른 착화합물과는 달리, serine 착화합물은 β탄소위치에 hydroxy group이 치환되어 있어서 electronic effect 와 steric dffect의 효과를 기대할 수 있다. 산소원자의 π비등방성 결합을 포함한 ligand field analysis로 부터, serine 착화합물의 자세한 electronic structure와 결합특성을 살펴보기로 하겠다. Low temperature (13K)luminescence and excitation spectra were measured to anlayze the bonding characteristics between Cr(III)and amino acid(L-serne) ligand. Tris(L-serinato)chromium(III) complex has three oxygen and three nitrogen ligand atoms in facial geometry. Unlike oter complexes with amino acids, additional hydroxyl group in β-carbon tom is expected to have electronic an steric effects. From the ligand field analysis including anisotropic πbonding on oxygen atom, we found that both oxygen and nitrogen atom is weak σdonor. The splitting of electronic lines and bonding characteristics in the title compound are explained by considering the geometric effect, especially anisotropic πbonding.

OK-432(Picibanilⓡ)와 외과적 절제술을 이용한 선천성 림프관종의 치험례

김일규,이성호,오성섭,최진호,오남식,김왕식,임영일,양동환 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.3

Lymphangiomas are relatively rare benign tumors of the lymphatic system, characterized by congenital lymphatic malformation such as anastomosis or obstuction of the lymphatic channels. There are most frequently diagnosed in children younger than 3years. In contrast to that of the hemangioma, the sex distribution of the lymphangioma is nearly evenly divided. The head and neck lymphangioma represents about 70∼75% of all lymphangiomas, and they are difficult to manage. Spontaneous regression is rare, and rapid intermittent enlargement occurs secondary to infection or trauma. Enlargement may cause serious sequelae such as airway obstruction, feeding difficulties, and cosmetic problems. Treatments previously used for lymphangiomas include surgical excision and intralesional injection of sclerosants. Problems associated with surgical excision include the risk of cosmetically unacceptable scarring and the risk of damage to surrounding vital stricture and the high risk of incomplete excision. The sclerosants previously used have numerous other local and systemic side effects. This report describes a case that was successfully treated using OK-432 as a new sclerosant drug and secondary surgical excision for congential cavenous lymphangioma extensively enlarged to tongue, mouth floor and submandibular region.

악안면 영역에 발생한 혈관종 환자의 외과적 치험례

김일규,박형준,최진호,장금수,김왕식 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.1

Hemangiomas are benign tumors in blood vessels that occur by traumatic or congenital origin. Lesions are appeared early in life, with 73% present at birth and 85% developing by the end of the first year. Head & neck hamangiomas represent about 25%∼33% of all hemangiomas. Kaban & Mulliken divided vascular birthmarks into two major categories : hemangioma and vascular malformation. Case 1 was diagnosed as cavernous hemangioma and the mass was excised completely and defected space was reconstructed with fat tissue. Case 2 was diagnosed definitely as traumatic A-V malformation by post-op histopathological examination and the mass was excised completely. This report describes two cases that were successfully treated by complete surgical excision for hemangioma in maxillofacial region.

뇌하수체경을 침범한 Histiocytosis X : 증례 보고 Case Report

조병규,왕규창,양세원,지제근,김인원,최길수 대한신경외과학회 1989 Journal of Korean neurosurgical society Vol.18 No.7-12

A case of histiocytosis X with the involvement of pituitary stalk in a 5 year old boy was described. He presented with diabetes insipidus and the endocrinological study showed growth hormone deficiency. On computerized tomography and magnetic resonance imaging, the pituitary stalk was abnormally thick. Overlooking of the skull lesion on plain X-ray film led to an erroneous diagnosis of 'germ cell tumor'. Gross total removal of the lesion and chemotherapy were performed. In the differential diagnosis of suprasellar masses, this disease entity should be included. The importance of histological diagnosis of the infundibular lesion in cases of central diabetes insipidus is also emphasized.

우라늄 오염 금속표면의 제염을 위한 UO_2 용해특성 연구

이성열,최왕규,오원진,유승곤 한국공업화학회 2003 공업화학 Vol.14 No.3

국내의 가동 중지된 우라늄 변환시설의 해체 시 대량으로 발생될 탱크류 및 배관 등 공정 계통 부품으로 이루어진 금속 폐기물의 재팔용 또는 자체처분을 위한 현장 제염기술로 질산 제염공정을 선정하였다. 오염 물질로써 UO_2를 대상으로 UO_2 입자의 용해 거동을 통해 우라늄 화합물로 오염된 금속 폐기물에 대한 질산 용액의 표면제염 적용성을 평가하였고, 우라늄 변환시설 내에서 직접 인출한 UO_2 오염 시편의 제염 실증실험을 통해 제염 공정의 성능을 검증하였다. 질산 제염 용액에서 UO_2 입자의 용해속도는 질산의 농도 및 용액의 온도에 크게 의존하였으며, 산화제로 H_2O_2를 첨가함에 의해서 상온의 저 농도 질산 제염 용액 내에서도 H_2O_2가 첨가되지 않은 경우에 비해서 속도가 현저하게 증가되었다 UO_2로 오염된 시편의 제염에 있어서, H_2O_2가 첨가되지 않은 질산 용액 내에서의 제염계수는 α 방사능에 대해서는 1.8~2.7, β 방사능에 대해서는 1.8~2.3인 반면에 질산 용액에 H_2O_2를 첨가한 경우에는 α 방사능에 대해서 61.7~338.5, β 방사능에 대해서는 20.1~92.4를 나타냄으로써 H_2O_2를 첨가함에 의해서 상온, 저농도 질산 용액 내에서도 UO_2 오염된 금속표면을 효과적으로 제염할 수 있음을 확인하였다. In this study, a decontamination process using nitric acid was selected as an in-situ technology for recycle or disposal of large amount of metallic wastes, which includes process system components such as tanks, piping, etc that are generated as a result of dismantling retired uranium conversion facility in Korea. The applicability of nitric acid solution for surface decontamination of metallic wastes that are contaminated with uranium compounds was evaluated through dissolution of UO_2 powder. The decontamination decontamination performance are verified using UO_2 contaminated specimen that came from an uranium conversion facility. Dissolution rate of UO_2 powder was dependant considerably upon nitric acid concentration and solution temperature. Notable enhancement of dissolution rate was achieved by addition of H_2O_2 as an oxidant even in the condition of low concentration of nitric acid and low temperature. The results for decontamination of the specimen contaminated with UO_2 showed that the decontamination factors (DFs) for nitric acid solution without H_2O_2 were 1.8~2.7 and 1.8~2.3 for α and β-radioactivity. respectively, while DFs for nitric acid solution containing H_2O_2 were 61.7~338.5 and 20.1 ~92.4 for α and β-radioactivity, respectively. Thus, the metallic surfaces contaminated with UO_2 can be decontaminated effectively with low concentration of nitric acid at mom temperature in the presence of H_2O_2.

Sodium Trans-Bis(methyliminodiacetato)Chromate(Ⅲ)의 두가지 다른 空間群 P1￣와 A2/n間의 相互 變換

李珍昊,宋柱昊,崔成山,郭相姬,吳美蘭,박성진,李揆旺,徐廷善,徐日煥 충남대학교 1996 忠南科學硏究誌 Vol.23 No.1

The structure of sodium trans-bis(methyliminodiacetato) chromate(Ⅲ), C_10H_14O_8N_2CrNa, has been elucidated with two space groups P 1-; a=8.9856(6), b=13.308(1), c=6.261(1)Å, α=76.38(1), β=110.361(9), r=107.394(6)˚, V=662(2)Å^3, Z=2, μ=0.47mn^(-1), d=1.831Mg/㎥, R=0.0295 for 1901 independent reflections with F^2>2σ(F^2), and A2/n; a=13.65(5), b=6.261(1), c=16.85(6)Å, β=113.05(1)˚, V=1324(7)Å^3, Z=4, R=0.0287 for 1013 independent reflections with F^2>2σ(F^2). There are two different asymmetric half molecules in triclinic system and one asymmetric half molecule in monoclinic system. The structures of three different molecules are very similar in conformations. The four carboxyl O atoms and the two imino N atoms in each molecule produce a distorted octahedral coordination geometry around the Cr atom. The average distances of Cr-O(carboxyl) and Cr-N(imino) are 1.956 and 2.061Å respectively. Molecules are held together by ionic forces. In this paper, it has been also shown that the cell constants, Miller indices, atomic coordinates, lattice directions and reciprocal lattices of the two space groups can be mutually transformed.

흡착 우라늄 이온의 전기 탈착거동

정종헌,원휘준,최왕규,김계남,이성호,오원진 한국공업화학회 2003 응용화학 Vol.7 No.1

Liquid wastes containing uranium ions in high concentration of chemical salts havebeen treated by electrosorption on a activated carbon fibers(ACFs) electrode. Effectiveuranium (VI) removal is accomplished when the potential is -0.5V(vs. Ag/AgCl) ormore negative. For a feed concentration of 100mg/1, the concentration of U(VI) in thecell effluent is reduced to less than 1mg/1, and electrosorption capacity over 500mg/uranium/gACF is reached. The adsorbed uranium can be desorbed up to 99%for 20h by passing a 1.9N NaCl solution at pH 3 through the cell and applying a potential of +1.2V. The amount of desorbed uranium increased as the solution pHwas lowered and the applied potential increased.

Sodium Valproate(Depakine^(�)) 정맥주사의 임상적 효능에 관한 연구 : 신경외과 수술후 1주일간의 간질억제효과와 안전성 Antiepileptic Effect and Safety Assessment During the Postoperative Seven Days in Neurosurgical Patients

백선하,왕규창,오창완,정천기,김동규,정희원,김현집,조병규,최길수,한대희 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.7

Diphenylhydantoin(DPH) has been used intravenously as a drug of choice in conditions which seizure patients are incapable of oral Teeding or in a state of status epilepticus However, its clinical use has limitations because of its serious side effects o# cardiac depression or systemic hypotension In Western countries. the recently do- veloped intravenous sodium valproate has been reported as safe and e#Tective for seizure control in such patients To assess the safety and effectiveness in seizure control we investigated the serum levels of the drug at f4 hours 48 hours and 7 days after intravenous administration of sodium valproate(Depakine른. occurrence of seizures in the perioperative period and the side eT#ects of the drugs in 30 neurosurgical patients older than 3 years of age The mean serum concentrations of valproic acid after bolus injection To IS mg/kg followed by continuous infusion with the rate To OSmg/kg/hour, were over 450 rg/ml . 좌S 0± IS 3 ff/ml at 운4 hours, 504±fl 0 f(g/ml at 좌』 hours and 58 9±tO 7 賠,/1 at 7 days aTter the sta「t of the adinistration All the Patients whose se「u vaIProic acid levelwas witHin the therapeutic range(40-100 rr/ml). had never experienced an episode of seizure attack during the perioperative days There was no evidence of elevated liver enzyme activity, but there were evidence of some tendencyof decreased platelet count in the peripheral blood at f days a#ter the administration of intravenous Yalproic acid Four patients experienced episodes of mild nausea and/or vomiting in conclusion per'ioperat'ive intravenous administration of valproic acids in neurosurgical patients was safe and effective in seizure control However it must be used precauciously in the patients with compromized coagulation system

두개인두종의 임상양상 및 수술적 치료성적 : 102례의 분석 Analysis of 102 Cases

백선하,오창완,정영섭,양희진,한대희,조병규,왕규창,정희원,김현집,최길수 대한신경외과학회 1997 Journal of Korean neurosurgical society Vol.26 No.7