고농도 니켈 침출액으로부터 Na-PC88A에 의한 Co, Mn 및 Zn의 분리에 관한 연구

安鍾寬,朴慶鎬,孫廷秀,안재우 대한금속재료학회 2001 대한금속·재료학회지 Vol.39 No.12

Solvent extraction experiments for the separation of impurities from Ni-rich solution were carried out for manufacturing of high purity Ni compounds from acid leaching solution of spent Ni-Cd secondary battery. Synthesised and actual leaching solution were used as aqueous phases and PC88A saponified by sodium in kerosene were used as organic phases. The extraction order is Zn>Mn>Co>Ni and extraction percentage of metal ions was increased with an increase of the concentration of extractant, initial pH of aqueous phase and ratio of O/A The separation of Ni and other impurities was effectively accomplished at the condition of extraction stage = 1, O/A = 1, saponified percent 50%, initial pH 5.0, concentration of extractant 1.0M.

혈소판 풍부혈장의 임상적 응용

하정완,김수관,조세인,이철우,정태영,김수흥,김영균 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.5

Platelet-rich plasma is an autologous source of platelet-derived growth factor and transforming growth factor beta that is obtained by sequestering and concentrating platelets by gradient density centrifugation. We have used platelet-rich plasma for bone graft, especially allobone graft, at implant surgery, sinus lift procedure, and cyst enucleation. This article is retrospective study from October 1999 to November 2000. All cases were good healing and clinical success.

도시경관계획수립을 위한 경관파편화에 관한 연구

정성관,오정학,박경훈 한국지리정보학회 2003 한국지리정보학회지 Vol.6 No.3

최근 부각되고 있는 도시지역의 환경문제 해결을 위해서는 다각적인 접근방법이 요구되는데, 도시지역에 산재해 있는 도시림의 효율적인 관리는 그 방법 중 하나가 될 수 있다. 본 연구에서는 도심지와 인접해 있는 지리적 여건으로 인해 오래전부터 인간의 간섭을 지속적으로 받아온 대구광역시의 앞산자연공원을 대상으로 토지이용 변화 및 경관지수를 사용하여 경관구조 변화에 대해 분석하고자 하였으며, 분석결과를 요약하면 다음과 같다. 첫째, 대상지역의 남쪽으로는 산지연계형의 도시림 특성으로 인해 생태적으로 안정된 환경을 유지하고 있는 반면, 그 외 지역에서는 대구시의 산업화로 인한 이농현상으로 1980년 이전에 도시화가 완료된 것으로 나타났다. 둘째, 경관요소별 면적변화에 따르면, 경작지의 대부분이 도시지역으로 전용된 것으로 나타났으며, 대표적인 경관요소가 소나무림과 농경지에서 혼효림과 도시역으로 변화된 것으로 나타났다. 셋째, 경관지수 분석결과, 조림지에 있어서 인위적인 간섭보다는 산불의 피해임지에 조림된 수종의 조림실패로 인해 활엽수 및 혼효림으로 전환된 것으로 나타났다. Many-sided approach methods are being demanded to solve invironmental problems in urban areas. One of these will be to manage forests scattered in urban areas efficiently. This paper is to grasp the change of land use and landscape indices in Mt. Ap, Deagu, and to analyze the change of landscape structure. Mt. Ap is near Daegu Metropolitan, so under unnatural interferences of human activity persistently. The results of above analysis run as follows: First, the north of the case area is connected to forest, and keeps stable equilibrium ecologically, while the other parts of it suffer from rural exodus and side effects of urbanization which has been completed since 1980. Second, according to the area-rate change of each landscape element, a cultivated areas has been converted into urban one, especially Pinus densiflora forests and paddy fields into mixed forests and urban areas. Finally, most of plantations have been converted into deciduous forests and mixed forests in failure of adption of plants in burned areas rather than owing to factitious interference

온도가 파밤나방의 발욕에 비치는 영향

고현관,김정화 충북대학교 농업과학기술연구소 1991 農業科學硏究 Vol.9 No.1

Threshold temperature and effective day- degrees were calculated at constant temperature conditions. Egg periods were 5.4, 4.0, 3.0 and 2.0 days at 20℃, 23℃, 27℃ and 30℃, respectively. Larval periods were 36.8, 25.6, 15.8 and 14.5 days and pupal periods were 16.4, 11.2, 6.6 and 5.7 days at above temperature. Preovipositional periods were 2.3, 2.3, 1.3 and 0.8 days and female longevity were 9.0, 6.3, 5.3 and 4.5 days at 20℃, 23℃, 27℃ and 30℃, respectively. Relationships between constant temperature and the developmental velocity of egg, larva and pupa were linear. the calculated threshold temperatures of development were 14.4℃ in egg, 13.7℃ in larva, 15.1℃ in pupa and 14.2℃ in egg-pupa. Total effective day-degrees were 33.4 in egg, 229.5 in larva, 83.1 in pupa and 344.1 in egg- pupa.

Soft Agar Assay를 이용한 배양골조직과 골세포의 Transforming Growth Factor-β유리에 관한 연구

백정화,김관식,정동균 대한구강생물학회 1991 International Journal of Oral Biology Vol.15 No.2

To study the effect of PTH, osteotropic hormone, on the TGF-β activity in conditioned medium prepared from bone explants, fetal rat ulnae and radii were removed at 19-day of gestation and organ cultured for 24 hours. Then media were changed with fresh BGJb media for control group or PTH-supplemented media (50 or 200 ng/㎖) for experimental group respectively and conditioned media were prepared by 2-day culture of explants. To study the cellular orgin of matrix-associatied TGF-β and the effect of PTH on the TGF-β activity in conditioned media prepared from bone cells, five bone cell populations were prepared from fetal rat calvaria by sequential enzyme digestion. After primary culture, each bone cell population was collected and resuspended as Ⅰ-Ⅱ, Ⅲ and Ⅳ-Ⅴ groups. After 24 hours, media were changed with fresh minimum essential medium(MEM) or 600 ng/㎖ PTH-supplemented media and conditioned media were prepared by 2-day culture. For activation of latent TGF-β activity in bone cell-conditioned media, media were acidified and then neutralized. TGF-β activities of conditioned media were measured by anchorage-independent growth of NRK fibroblasts using modified Todaro soft agar assay method(1987) and the number of colonies ≥ 50 ㎛ was counted. The observed results were as follows. 1. TGF-β, without 2 ng/㎖ EGF, did not induce colony formation in soft agar suspensions. 2. With 2 ng/㎖ EGF, TGF-β induced NRK cells to form large colonies in soft agar suspensions and colony numbers increased proportionally to TGF-β concentrations from 50 pg/㎖ to 1600 pg/㎖. 3. When ulnae and radii were incubated with 50 ng/㎖ PTH, TGF-β activity in conditioned media was not significantly different from control conditioned media. In contrast, TGF-β activity in conditioned media prepared from culture with supplementation of 200 ng/㎖ PTH, was significantly increased(p < 0.01). 4. TGF-β activity was detectable in all bone cell populations and the amount was not significantly different between cell populations. 5. When bone cell populations were incubated with 600 ng/㎖ PTH. TGF-β activity in conditioned media from each population was not significantly different from control conditioned media. These results suggest that all cell populations isolated from calvaria synthesize TGF-β and PTH has no apparent effects on the TGF-β production of bone cell populations. In addition, increased TGF-β activity in bone explant conditioned media by 200 ng/㎖ PTH appears to be due to the enhanced release of TGF-β from bone matrix secondary to bone resorptive process.

40세 이하 관상동맥 질환자에서 장기적 임상 관찰

이승욱,정명호,박종철,박형욱,조상희,김원,김계훈,이상현,강경태,조장현,김남호,김건형,안영근,조정관,박종춘,강정채 全南大醫大 2001 전남의대학술지 Vol.37 No.2

대학수학능력시험 수리영역의 특징과 97학년도 문항분석

신향근,양기열,정권수,송영무 順天大學校 師範大學 附屬 科學敎育硏究所 1996 科學과 敎育 Vol.4 No.-

Since the academic year of 1994, the Scholatic Ability Test(abbr. S.A.T) was given for students who wanted to get adimssions from universities and colleges in Korea. This test has revolutionized the pattern of teaching and learning mathematics in most highschool classrooms. In this paper, we will show a feature of S.A.T. and analyze mathematics problems of 1997's S.A.T.

하악 무치악 인공치아매식술시 하치조신경 전위술

최의환,하정완,김수관,정태영,김수흥 대한악안면성형재건외과학회 2001 Maxillofacial Plastic Reconstructive Surgery Vol.23 No.3

Modified surgical technique for transposition of the inferior alveolar nerve followed by immediate placement of endosseous implants in mandibles with moderate to severe atrophy are presented. Five transpositions of the inferior alveolar nerve together with the installation of 10 implants were performed in four patients. The mean postoperative follow-up time was 17 months, with a range of 8 to 20 months. All implants with functioning pontics remained stable, with no mobility or symptoms of pain and infection during the follow-up period. Neurosensory evaluation was performed using the two-point discrimination test. Two patients had objective neurosensory dysfunction at postoperative, but all the nerve function were reported as normal by the patients 4 months postoperatively.

GIS 및 RS기법을 활용한 산사태 취약성 평가

김경태,정성관,박경훈,오정학 한국지리정보학회 2005 한국지리정보학회지 Vol.8 No.1

본 연구는 금호강 유역을 대상으로 GIS와 윈격탐사기법을 활용하여 산사태 취약성의 예측과 지도화를 수행하자 한다. 산사태 영향인자인 사면경사, 사면방4향, 지질, 토지이용도, 식생지수(NDVI)의 공간데이터베이스는 30m×30m 해상도로 구축하였다. 산사태 취약성은 중첩분석과 한산평가 매트릭스 방법으로 예측하였고, 6개 범주(안정, 매우 낮음, 낮음, 중간, 높음, 매우 높음)로 구분한 산사태 취약성 지도를 제작하였다. 분석결과에 따르면, 산사태 취약성이 '매우높은' 지역은 전체 대상지의 약 0.3% 정도를 차지하며, 이들 지역은 주로 높은 경사TA와 낮은 식생지수를 가지는 산림지역에 분포하는 것으로 나타났다. This study aims at predicting and mapping of the landslide susceptibility in the Geumho river watershed using GIS and Remote Sensing techniques. We constructed the spatial database of affecting factors such as slope angle, slope aspect, lithology, landuse, and vegetation index (NDVI) at a 30mx30m resolution. The landslide susceptibility of the study area was predicted through overlay analysis and adding up estimation matrix, and the predicted map of landslide susceptibility with six categories (stable, very low, low, moderate, high, very high) was constructed. As the results, it showed that the very high susceptibility zones made up approximately 0.3% of the total study area, and these zones were mainly distributed in the forest area with the high slope angle and low vegetation index.

구강점막섬유화에 의한 개구제한 : 증례보고 A CASE REPORT

김 훈,김수관,하정완 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.2

Oral submucous Fibrosis(OSF) is an insidious chronic disease affecting the mucosa of the oral cavity and occasionally extending into the pharynx and esophagus. It is associated with a genetic predisposition and alterations, infectious and viral agents, carcinogens, nutritional and immunological factors. the etiology is obscure but it is correlated with a hypersensitivity to capsaicin, secondary to chronic iron and/ or vitamin B complex deficiencies or exposure to cashew kernel oil. We report a patient who had a month opening limitation caused by a fall when he was 8 years old despite several treatments at other hospitals. Excellent results were obstained by releasing the scar tissue using a standard split-thickness skin graft(STSG) which obtained from the thigh. It is important to recognize as a precancerous condition and to inspect the excision site and the remaining oral mucosa during long-term follow-up on a regular basis.