나노 파우더 제조용 비드밀 제작에 관한 연구

손재엽,남권선,김병희 강원대학교 산업기술연구소 2005 産業技術硏究 Vol.25 No.B

Manufacturing methods of Nano particles can be distinguished by top-down technology as physical method and bottom-up technology as chemical synthetic method. Top-down technology is a kind of method for making microstructure as like carving after forming a macroscopic structure in advance and its typical methods are ball milling, gas condensation method and so on. Nano Particles synthesized by bottom-up method have got to do dispersing process for using them as actual nano particles because their viscosity are very strong and so easy to shape cohesive substances. Therefore, this study is about a particle separating device which separates a certain constant size of grains processed already in mill and mixer because we mostly use media agitating mill as a device of milling and dispersing and we necessarily use very slight balls as media for manufacturing nano particles in the machine. The centrifugal device has been designed for passing and separating below a certain type of grain size after final process of particles in the mill.

THE EFFECT OF PRIMING ETCHED DENTIN WITH SOLVENT ON THE MICROTENSILE BOND STRENGTH OF HYDROPHOBIC DENTIN ADHESIVE

박은숙,배지현,김종순,김재훈,이인복,김창근,손호현,조병훈 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.1

장기적인 상아질 접착의 내구성 악화는 접착층과 혼성층의 친수성 부위에서의 가수분해에 의해 일어나는 것으로 보고 되고 있다. 본 연구의 가설은 콜라겐 망상체를 유기용매로 프라이밍하면 콜라겐 조직을 붕괴시키지 않고 수분을 밀어내고 소수성 단량체와 유기용매로 이루어진 접착제가 침투하여 접착강도를 얻을 수 있다는 것이다. 두 소수성 단량체인 Bisphenol-A-glycidylmethacrylate (Bis-GMA)와 triethyleneglycol dimethacrylate (TEGDMA)를 아세톤, 에탄올 또는 메탄올에 용해시켜 세 가지의 실험용 접착제를 준비하였다. 산 부식과 수세과정 후에, 접착제를 습윤 상아질 표면(습윤 접착)이나 동일한 용매로 프라이밍 된 상아질 표면(용매 프라이밍 접착)에 적용하였다. 48시간 후와 1개월 후, 및 10.000회의 열순환 후에 미세인장결합강도를 측정하였다 접착계면은 주사전자현미경을 이용하여 관찰하였다. 접착방법에 무관하게 대부분의 시편의 접착계면예서 잘 발달된 혼성층을 관찰할 수 있었고 가장 높은 평균 미세인장결합강도는 에탄올을 포함하는 접착제의 48시간 후 시편에서 관찰되었다. 용매를 이용하여 프라이밍하는 접착 방법에서는 에탄올이나 메탄올을 포함하는 접착제에서 열순환 후에 미세인장접착강도가 증가하는 경향을 보였다. 그러나 습윤 접착의 경우에는 시효처리 후 미세인장결합강도의 증가가 관찰되지 않았다. 본 연구에서 에탄올을 이용한 상아질 프라이밍으로 우수한 접착력을 얻을 수 있었고. 열순환 후 접착력이 더욱 증가하였다 Deterioration of long-term dentin adhesion durability is thought to occur by hydrolytic degradation within hydrophilic domains of the adhesive and hybrid layers. This study investigated the hypothesis that priming the collagen network with an organic solvent displacc water without collapse and thereby obtain good bond strength with an adhesive made of hydrophobic monomers and organic solvents. Three experimentaladhesives were prepared by dissolving two hydrophobic monomers bisphenol-A-glycidylmethacrylate (Bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA), into acetone, ethanol or methanol. After an entching and rinsing procedure, the adhesives were applied onto either wet dentin surfaces (wet bonding) or dentin .surfaces primed with the same solvent (solvent-primed bonding). Microtensile bond strength (MTBS) was measured at 48 hrs, 1 month and after 10,000 times of thermocycles. The bonded interfaces were evaluated using a scanning electron microscope (SEM) Regardless of bonding protocols, weIl-developed hybrid layers were observed at the bonded interface in most specimens. The highest mean MTBS was observed in the adhesive containing ethanol at 48 hrs. With solvent-primed bonding increased MTBS tendencies were seen with thermocycling in the adhesives containing ethanol or methanol. However in the case of wet bonding, no increase in MTBS was observed with aging.

2.9% 과산화수소를 함유한 부착형 미백제의 임상적 효능과 안정성에 관한 연구

박은숙,성소래,홍성태,김지은,이소영,황수연,이신재,진보형,손호현,조병훈 大韓齒科保存學會 2006 Restorative Dentistry & Endodontics Vol.31 No.4

2.9%의 과산화수소를 함유한 시험용 부착형 미백제(Medison dental whitening strip, Samsung medical Co.,Anyang,Korea)를 실험군 피험자 23명, 시험용 미백제에서 과산화수소를 제외한 동일한 제재를 대조약으로 대조군 피험자 24명에게 매일 1시간 30분씩, 2주간 적용하여 임상적 효능과 안전성을 평가하였다. 미백 효과는 Shade Vision, Chroma Mete 및 Vitapan classical shade guide를 이용하여 색변화를 측정하여 다음과 같은 결론을 얻었다. 1. 실험군에서의 전체 치아의 색변화량(ΔE^(*))은 세 가지 측정법에서 모두 대조군에 비해 통계적으로 유의한 차이를 보였고 (p < 0.05). 쉽게 인지할 수 있는 정도였다. 2. 색변화는 색좌표 상에서 명도의 증가와 녹색조 및 청색조로의 변화에 의해 얻어졌다. 3. 치아별로는 어두운 견치의 색변화량이 가장 컸고, 측절치, 중절치 순으로 감소하였다. 4. 47명의 피험자 중 5명이 경도의 과민증을 경험하였으나 곧 완화되었다, 치은염증지수와 전기치수검사 결과 시험 전후에 차이가 없어 안전성을 확인하였다. This study evaluated the effectiveness and safety of an experimental bleaching strip (Medison dental whitening strip, Samsung medical Co., Anyang, Korea) containing 2.9% hydrogen peroxide. Twenty-three volunteers used the bleaching strips for one and a half hour daily for 2 weeks. As control group, the same strips in which hydrogen peroxide was not included were used by 24 volunteers with the same protocol. The shade chang (ΔE^(*), color differnce) of twelve anterior teeth was measured using Shade Vision (X-Rite Inc., S. W. Grandville, MI, USA), Chroma Meter (Minota Co., Ltd. Osaka, Japan) and Vitapan classical shade guide (Vita Zahnfabrik, Germany). The shade change of overall teeth in the experimental group was significantly greater than that in the control group (p < 0.05) and was easily perceivable. The change resulted from the increase of lightness (CIE L^(*) value) and the decrease of redness (CIE a^(*) value) and yellowness (CIE b^(*) value). The shade change of individual tooth was greatest in canine, can smallest in central incisor. The safety of the bleaching strip was also confirmed. 〔J Kor Acad Cons Dent 31(4):269-281, 2006〕

Assessment of Heavy Metal Concentrations in Greenhouse Soils of Gyeongnam Province

Son, Daniel,Cho, Hyeon-Ji,Heo, Jae-Young,Lee, Byeong-Jeong,Hong, Kwang-Pyo,Lee, Young Han 한국토양비료학회 2017 한국토양비료학회지 Vol.50 No.5

Heavy metal contamination of soil might be a cause of serious concern due to the potential health impacts of consuming contaminated products. In this study, the total content of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn, As, and Hg) in soils was analyzed, and the difference of heavy metal contents depending on crops, soil characteristics, and topography was compared in 169 greenhouse soils obtained from Gyeongnam Province. The concentrations of the heavy metals were $0.25mg\;kg^{-1}$ (ranged 0.01~0.44) for Cd, $28.94(0.53{\sim}72.63)mg\;kg^{-1}$ for Cr, $26.03(0.5{\sim}166.13)mg\;kg^{-1}$ for Cu, $14.91(1.27{\sim}33.22)mg\;kg^{-1}$ for Ni, $15.76(0.43{\sim}57.1)mg\;kg^{-1}$ for Pb, $119.72(6.33{\sim}239.39)mg\;kg^{-1}$ for Zn, $2.54(0.01{\sim}23.57)mg\;kg^{-1}$ for As, and $0.049(0.012{\sim}0.253)mg\;kg^{-1}$ for Hg in topsoils. The concentrations of Pb and As in topsoil were highest in green pepper and those of Cd, Cr, and Ni were highest in melon. In addition, the concentrations of Cr and Ni were highest in diluvial terrace compared with the other topographies. Higher concentrations of Cd, Cr, and Ni were found in silty clay loam and silt loam soils than sandy loam and loam soils.

Selective Laser Melting of Fe-Ni-Cr Coating on AISI H13 Tool Steel

Byeong don Joo,Jeong Hwan Jang,Jae Hoo Lee,Young Myung Son,Young Hoon Moon 한국표면공학회 2008 한국표면공학회 학술발표회 초록집 Vol.2008 No.-

단순언어장애로 진단된 환아의 임상적 고찰

최재용(Jae Yong Choi),김철암(Cheol Am Kim),송익진(Ick Jin Song),이균우(Kyun Woo Lee),강민정(Min Jung Gang),정민지(Min Ji Jung),손병희(Byeong Hee Son) 대한소아신경학회 2011 대한소아신경학회지 Vol.19 No.1

목적 : 언어 발달 문제를 주소로 내원하여 단순언어장애로 진단받은 아동의 임상적 경과를 관찰하고자 이 연구를 시행하였다. 방법 : 대동 병원 소아청소년과 외래에 2007년 7월부터 2008년 6월까지 말과 언어 지연을 주소로 내원하여 언어 및 발달 검사를 받았던 아동 125명 중 단순언어장애로 진단받은 아동 51명에 대한 치료 및 임상 경과를 조사하였다. 자료에 대한 설문조사는 전화 및 외래 방문 면담으로 시행하였다. 결과 : 단순언어장애로 진단 받은 51명의 아동 중 혼합 수용-표현언어장애는 39명(76.5%), 표현언어장애는 12명 (23.5%) 이었다. 추적관찰이 불가능한 10명과 치료를 하지 않았거나, 치료 도중 탈락한 아동 11명을 제외한 30명 중 혼합 수용-표현언어장애 아동은 23명(76.7%), 표현언어장애 아동은 7명 (23.3%)이었다. 이들 아동 30명 중에서 전체적인 치료기간은 혼합 수용-표현언어장애 아동은 18.1±10.0개월, 표현언어장애 아동은 8.6±3.6개월로 통계적으로 유의한 차이가 있었다(P=0.014). 언어치료를 받은 혼합수용-표현언어장애 아동 23명 중 13명(57%)과 표현언어장애 아동 7명중 모두(100%)에서 치료가 종결되었다. 그러나 언어치료가 종결된 아동에서 언어치료가 종결되기 까지의 기간은 혼합 수용-표현언어장애 아동에서 12.2±8.7개월, 표현언어장애 아동 군에서 8.6±3.6개월로 표현언어장애 아동에서 치료기간이 짧아 보였으나 통계적으로 유의한 차이는 없었다(P=0.287). 결론 : 이전의 논문들의 고찰 및 본 연구를 통하여 볼 때, 단순언어장애 아동을 외래에서 진료 시 혼합 수용-표현언어장애 아동과 표현언어장애 아동으로 구분하여 치료하는 것은 단순언어장애 아동의 치료기간 뿐만 아니라 언어치료에 대한 경과나 예후를 예측하는데 도움이 될 것으로 생각된다. 앞으로 소아청소년과 차원에서의 단순 언어장애 아동에 대한 조기평가와 효과적인 치료방법에 대한 관심이 절실히 요구된다. Purpose: The purpose of this study was to evaluate the clinical characteristics of children who had been diagnosed as specific language impairment as outpatients. Methods: One hundred twenty-five speech- or language-delayed patients were enrolled in Dae-Dong Hospital from July 2007 to June 2008. Fifty-one of 125 children were diagnosed as specific language impairment in whom clinical factors such as duration of therapy and progress after therapy were evaluated. Data were obtained from telephone or direct personal interviews. Results: Among 51 children diagnosed as specific language impairment, 39 (76.5%) had mixed receptive-expressive-type language disorder and 12 (23.5%) had expressive-type language disorder. Thirty children in total were studied as ten children were unavailable for follow-up and eleven dropped out during treatment. The final 30 children consisting of 23 with mixed receptive-expressive type language disorder and seven children with expressive-type language disorder were treated after diagnosis. Total average treatment duration of children with mixed receptive-expressive-type and expressive-type language disorder were 18.1 months and 8.6 months, respectively, a statistically significant difference (P=0.014). Thirteen (57%) of 23 children with mixed receptive-expressive-type language disorder and all (100%) seven children with expressive-type language disorder completed speech therapy with an average treatment duration of 12.2 and 8.6 months, respectively; however. this difference was not statistically significant(P=0.287). Conclusion: Classifying patients with specific language impairments into mixed receptive-expressive-type and expressive-type language disorder in an outpatient department can be useful for predicting duration of and prognostic effects of language therapy. as our study and other previous articles have shown. More attention is needed from pediatricians to ensure the effective assessment and management of specific language impairment.

골수이형성증후군의 임상혈액학적 고찰

손상균 ( Son Sang Gyun ),정병천 ( Jeong Byeong Cheon ),김광원 ( Kim Gwang Won ),이재태 ( Lee Jae Tae ),이규보 ( Lee Gyu Bo ),황기석 ( Hwang Gi Seog ) 대한내과학회 1990 대한내과학회지 Vol.38 No.6

N/A Myelodysplastic syndrome is a primary hematologic disease characterized by ineffective hematopoiesis with peripheral blood cytopenias. The authors conducted a clinicohematologic observation of 55 cases of MDS from July 1983 to June 1988. The result are as follows. The peak age incidence was in the fifth decade, and the male-to-female ratio was nearly 1:1. RA was observed most frequently. Thereafter RAEB-T, RAEB, RARS and CMML were observed, respectively. The chief complaints of the patients were exertional dyspnea and fatigability by anemia. Physical findings showed pallor (85.5%), purpura (40.0%), retinal hemorrhage (38.2%), hepatomegaly (18.2%), lymphadenopathy (14.5%), icteric sclera (12.7%) and splenomegaly (10.9%). The common infection sites were oral (38.0%), systemic (sepsis: 20:0%) and lung (14.5%). The main hematologic changes were pancytopenia (56.4%) and then anemia and thro.mbocytopenia, anemia and leukopenia, anemia and thrombocytopenia and leukocytosis, anemia only was present in 20.0%, 10.9%, 7. 5% and 5.4%, respectively. The laboratory findings showed increased serum iron (48.1%), decreased serum ferritin (43.1%), normal LAP scores (89.1%), prolonged plasm iron disappearance time (48.3%), shortened PID (6.9%), increased LDH (56.3%), increased vitamin B12 (29.5%) and decreased folic acid (4.5%). The bone marrow finding showed nearly hypercellular (38.2%) or normocellular (45.5%), along with variable morphological abnormalities, such as dyserythropoiesis, dysgranulopoiesis and dysmegakaryopoiesis. Cytogenetic studies showed abnormal chromosomal findings in five out of 13 cases. With combination therapy using androgen, pyridoxine and corticosteroid in 29 cases of RA and RARS, 31% of patients were clinically improved. And with low dose Ara-C therapy in 15 cases of RAEB, CMML and RAEBT, 26.6% of cases were improved. In the cases of RAEB and RAEB-T, nine cases of RAEB and RAEB-T converted to an other subtype of MDS or leukemia within one to six months. Nine cases expired (sepsis in five cases and CVA in four cases) during the observation period.

사이클로알리파틱계 에폭시 수지 변성 비스E 타입의 시아네이트 에스터 경화물의 경화 거동 및 기계적 물성에 관한 연구

심재훈(Jae Hun Shim),김민영(Minyoung Kim),박병열(Byeong Yeol Park),정상기(Sang Ki Chung),이상우(Sang Woo Lee),손조화(Johwa Son) 한국추진공학회 2013 한국추진공학회 학술대회논문집 Vol.2013 No.5

본 연구는 사이클로 알리파틱계 에폭시로 변성한 비스E 타입 시아네이트 에스터 수지를 Rheometer와 DSC로 분석하여 점도와 경화물의 유리전이온도 변화를 연구하고자 하였다. 에폭시로 변성한 시아네이트 에스터 수지의 점도는 에폭시량에 비례하여 상승하였고, 170℃ 이하에서는 비교적 안정적인 점도 변화 거동을 보였다. 유리전이온도는 에폭시 함량 증가에 따라 내려갔으나, 후경화시간 도입으로 높은 유리전이온도가 달성됨을 확인하였다. 따라서 사이클로알리파틱계 에폭시 수지는 비스E 타입 시아네이트에스터 수지의 점도를 효과적으로 개질하는 안정한 가소제인 것으로 판단되었다. This study was focused on the behavior of viscosity and glass transition temperature of bis E type cyanate ester resin with cycloaliphatic epoxy by Rheometer and DSC. The viscosity of cyanate ester with epoxy resin was increased in proportion to the amount of the epoxy and less than 170℃ it was relatively stable. The glass transition temperature went down in accordance with the increase in epoxy content. However, high glass transition temperature could be achieved by introducing post cure. Therefore, it was indicated that the epoxy resin was the effectively stable additive of the cyanate ester resin.

지중송전맨홀 Compact형 모델 개발

김재승(Jae-Seung Kim),민병욱(Byeong-Wook Min),김태영(Tai-Young Kim),윤종건(Jong-Keon Yoon),석광현(Kwang-Hyun Suk),손형수(Hyoung-Su Son),이문희(Mun-Hee Lee) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.7

본 논문은 지중송전케이블 접속을 위하여 도로에 설치하는 맨홀에 대하여 현재의 맨홀 공간을 분석하고 케이블 접속기술의 향상과 배치방법, 선종별 옵셋 길이 등을 반영하여 다양화된 표준맨홀 규격을 제시하므로써 최적의 맨홀이 설치되도록 규격을 축소하였다.

Evaluations of the Space Dose and Dose Reductions in Patients and Practitioners by Using the C-arm X-ray Tube Shielding Devices Developed in Our Laboratory

Kim, Jae Seok,Kim, Sung Ho,Lee, Bu Hyung,Kwon, Soo Il,Jung, Hai Jo,Hoe, Seong Wook,Son, Jin Hyun,Kang, Byeong Sam Korean Society of Medical Physics 2016 의학물리 Vol.27 No.4

The present study used a digital angiography x-ray device to measure the space dose and exposure dose of patients and practitioners using x-ray tube shielding devices developed in our laboratory. The intent of the study was to reduce the space dose within the test room, and to reduce the exposure dose of patients and practitioners. The patient and practitioner exposure doses were measured in five configurations in a human body model. The glass dosimeter was placed on the eye lenses, thyroid glands, left shoulder, right shoulder, and gonads. The beam was collimated at full size and at a 48% reduction for a comparative analysis of the measurements. The space dose was measured with an ion chamber at distances of 50 cm, 100 cm, and 150 cm from the x-ray tube under the following conditions: no shielding device; a shielding device made of 3-mm-thick lead (Pb) [Pb 3 mm shield], and a shielding device made of 3-mm-thick Pb (outside) and 3-mm-thick aluminum (Al) (inside) [Pb 3 mm＋Al 3 mm shield]. The absorbed dose was the lowest when the 3-mm-thick Pb＋3-mm-thick Al shield was used. For measurements made with collimated beams with a 48% reduction, the dose was the lowest at $154{\mu}Gy$ when the 3-mm-thick Pb＋3-mm-thick Al shield was used, and was $9{\mu}Gy$ lower than the measurements made with no shielding device. If the space dose can be reduced by 20% in all situations where the C-arm is employed by using the x-ray tube shielding devices developed in our laboratory, this is expected to play an important role in reducing the annual exposure dose for patients, practitioners, and assistants.