디지털 공제 방사선 촬영술에 있어서 기계적 및 투사적 규격화의 평가

최봉인,조봉혜,나경수,Choi Bong-In,Cho Bong-Hae,Nah Kyung-Soo 대한영상치의학회 1998 Imaging Science in Dentistry Vol.28 No.1

The following conclusions were obtained from the non-reconstructed and reconstructed subtraction images of the standard intraoral radiographs which were taken with paralleling technique with Rinn XCP only and with occlusal bite registration for geometric standardization using bilateral mandibular premolar and molar regions of two dry human skulls. 1. The SD of the overall subtraction images of the premolars and molars of the non-reconstructed, that is, the manual superimposition showed statistically significant difference between the non-registered and registered groups. 2. In non-reconstructed and non-registered cases, the quality of the subtraction images were improved when superimposition was focally done and this was more evident in areas where the radiographic images tend to be distorted due to anatomic reasons. 3. In non-reconstructed and registered cases, the subtraction images were consistent regardless of the anatomic site or the focus of superimposition. This means that the geometric standardization with only occlusal bite registration could produce serial radiographs which is suitable for subtraction. 4. The SD of the overall subtraction images of the premolars and molars of the reconstructed, that is, the automatic superimposition showed statistically insignificant difference between the non-registered and registered groups. This means that using reconstruction, subtraction radiography is possible without occlusal bite registration. 5. In reconstructed and non-registered cases, compatible quality of the subtraction images were obtained regardless of the anatomic site or area of the corresponding points. 6. In reconstructed and registered cases, best subtraction images whose quality showed sensitivity to the areas of corresponding points were obtained.

PFOS 대체물질의 환경유해성에 관한 연구

최봉인(Bong-In Choi),정선용(Seon-Yong Chung),나숙현(Suk-Hyun Na),신동수(Dong-Soo Shin),유병택(Byung-Taek Ryu) 대한환경공학회 2016 대한환경공학회지 Vol.38 No.6

PFOS sodium salt (C8F17SO₃Na)는 28일 동안 미생물에 의한 분해가 이루어지지 않은 반면 4종의 대체물질(C25F17H32ScO13Na₃, C15F9H21ScO8Na₂, C23F18H28S₂O8Na₂, C17F9H25S₂O8Na₂)은 각각 21.6%, 20.5%, 15.8% 그리고 6.4% 분해가 이루어졌다. Daphnia magna를 이용하여 48시간 동안 수행한 물벼룩급성독성시험에서 sodium salt (C8F17SO₃Na)의 반수영향농도(EC50)는 54.5 mg/L인 것으로 확인된 반면 4종의 대체물질은 500.0 mg/L에서 아무런 영향이 나타나지 않았다. 500.0 mg/L에서 PFOS sodium salt (C8F17SO₃Na)의 표면장력은 46.2 mN/m이었으며 대체물질 4종의 표면장력은 모두 PFOS sodium salt 보다 우수한 것으로 확인되었다. C23F18H28S₃O8Na₂ (20.9 mN/m)는 가장 낮은 표면장력을 갖고 있었다. 그 다음은 C15F9H21S₂O8Na₂ (23.4 mN/m), C17F9H25S₂O8Na₂ (27.3 mN/m) 그리고 C25F17H32S₃O13Na₃ (28.2 mN/m) 순인 것으로 확인되었다. 미생물분해시험, 물벼룩급성 독성시험 그리고 표면장력측정 결과를 종합해 보면 4종의 PFOS 대체물질(C25F17H32S₃O13Na₃, C15F9H21S₂O8Na₂, C23F18H28S₂O8Na₂, C17F9H25S₂O8Na₂)은 모두 PFOS sodium salt (C8F17SO₃Na) 보다 우수한 것으로 확인되었으며 특히 3종의 대체물질(C15F9H21S₂O8Na₂, C23F18H28S₂O8Na₂, C25F17H32S₃O13Na₃)은 미생물분해율이 15.8~21.6%로 상대적으로 높고, 물벼룩급성독성과 표면장력측정이 PFOS sodium salt 보다 상당히 우수하다. 그러므로 이들 4종의 대체물질은 PFOS 대체물질로 활용이 가능할 것으로 판단된다. While PFOS sodium salt (C8F17SO3Na) was not degraded by microorganisms for 28 days, the 4 alternatives were biodegraded at the rates of 21.6% for C25F17H32S₃O13Na₃, 20.5% for C15F9H21S₂O8Na₂, 15.8% for C23F18H28S₂O8Na₂ and 6.4% for C17F9H25S₂O8Na₂, respectively. The acute toxicity test using Daphnia magna was conducted for 48 hours, the half effective concentration (EC50) of PFOS sodium salt (C8F17SO₃Na) was evaluated in 54.5 mg/L. While the 4 alternatives did not show any effect at 500.0 mg/L. The surface tension of the PFOS salt (C8F17SO₃Na) is 46.2 mN/m at a concentration of 500.0 mg/L. While the surface tension of the 4 alternatives was found to be superior to PFOS sodium salt (C8F17SO₃Na). The surface tension of C23F18H28S₂O8Na₂ (20.9 mN/m) has the lowest, followed by C15F9H21S₂O8Na₂ (23.4 mN/m), C17F9H25S₂O8Na₂ (27.3 mN/m), C25F17H32S₃O13Na₃ (28.2 mN/m). The four kinds of alternatives (C15F9H21S₃O8Na₂, C17F9H25S₂O8Na₂, C23F18H28S₂O8Na₂, C25F17H32S₃O13Na₃) were found to be superior to PFOS sodium salt (C8F17SO₃Na) in terms of biodegradation, Daphnia sp. acute toxicity and surface tension, and thus they were considered applicable as PFOS alternatives. Especially biodegradation rate of C15F9H21S2O8Na₂, C23F18H28S₂O8Na₂ and C25F17H32S3O13Na₃ was relatively high as 15.8~21.6%, and Daphnia sp. acute toxicity and surface tension were considerably superior (surface tension 39~55%) to PFOS sodium salt. Therefore, these alternatives are considered to be available as an alternative of PFOS.

Ricefish(Oryzias latipes) 배아 발달시기에 SiO₂의 독성 영향

유병택(Byung-Taek Ryu),최봉인(Bong-In Choi),김도형(Do-Hyeong Kim),이영주(Young-Ju Lee),이인연(In-Yeon Lee),김영기(Young-Ki Kim),박상언(Sang-Eon Park) 한국환경독성학회 2010 한국독성학회 심포지움 및 학술발표회 Vol.2010 No.11

송사리 수정란을 이용한 Carbendazim의 독성평가

문형준(Mun Hyoung Jun),최수민(Choi Soo Min),황인영(Hwang In Young),최근표(Choi Keun Pyo),최봉인(Choi Bong In),이영주(Lee Young Joo),유병택(Yu Byoung Taeck) 한국환경독성학회 2011 한국독성학회 심포지움 및 학술발표회 Vol.2011 No.10

P-34 : PFOS 분해 미생물의 분리 및 특성에 관한 연구

임혜정 ( Hye Jung Lim ),나숙현 ( Suk Hyun Na ),최봉인 ( Bong In Choi ),차규석 ( Gyu Suk Cha ),( Saido Kastushiko ),( Sato Hideto ),정선용 ( Seon Yong Chung ) 한국물환경학회(구 한국수질보전학회) 2013 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2013 No.-

디지탈 공제 방사선 촬영술에 있어서 기계적 및 투사적 규격화의 평가

나경수,조봉혜,최봉인 大韓口腔顎顔面 放射線學會 1998 Imaging Science in Dentistry Vol.28 No.1

The following conclusions were obtained from the non-reconstructed and reconstructed subtraction images of the standard intraoral radiographs which were taken with paralleling technique with Rinn XCP only and with occlusal bit registration for geometric standardization using bilateral mandibular premolar and molar regions of two dry human skulls. 1. The SD of the overall subtraction images of the premolars and molars of the non-reconstructed, that in, the manual superimposition showed statistically significant difference between the non-registered and registered groups. 2. In non-reconstructed and non-registered cases, the quality of the subtraction images were improved when superimposition was focally done and this was more evident in areas where the radiographic images tend to be distorted due to anatomic reasons. 3. In non-reconstructed and registered cases, the subtraction images were consistent regardless of the anatomic site or the focus of superimposition. This means that the geometric standardization with only occlusal bite registration could produce serial radiographs which is suitable for subtraction. 4. The SD of the overall subtraction images of the premolars and molars of the reconstructed, that is, the automatic superimposition showed statistically insignificant difference between the non-registered and registered groups. This means that using reconstruction, subtraction radiography is possible without occlusal bit registration. 5. In reconstructed and non-registered cases, compatible quality of the subtraction images were obtained regardless of the anatomic site or area of the corresponding points. 6. In reconstructed and registered cases, best subtraction images whose quality showed sensitivity to the areas of corresponding points were obtained.

구내 표준 방사선 사진촬영의 위치 표준화

최봉인,나경수 大韓口腔顎顔面 放射線學會 1991 Imaging Science in Dentistry Vol.21 No.2

This study was performed to evaluate the geometric standardization of periapical intraoral radiography. Image distortion was measured by analysing serial radiopraphy obtained from dry skull using 5 types of bite registration device. After 16 weeks, the angular distortion of Pattern resin was 0.26±0.14 degree(Horizontal angle 0.17±0.14, Vertical angle 0.16±0.11) which was the lowest among the 5 registration device, and that of putty type Exaflex was 0.49±0.35 degree(Horizontal angle 0.42±0.35, Vertical angle 0.17±0.13) which was the highest. The mean amount of distortion variance of Tooth shade acrylic at each experimental period was 0.06±0.08 which was the lowest among the 5 registration device, and that of XCP alone was 0.11±0.13 which was the highest.