아스팔트 콘크리트의 고온변형저항 특성 측정방법 개발

김광우,이문섭,김중렬,이순제 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

본 연구는 정하중하에서 아스팔트 혼합물의 소성변형 저항특성을 측정할 수 있는 새로운 시험방법을 개발하기 위하여 수행되었다. 2가지 골재(편마암, 화강암)와 6가지 아스팔트(일반아스팔트, 5가지 개질 아스팔트)를 사용하여 총 12개의 밀입도 혼합물을 제작하였다. 마샬 배합설계를 통해 최적아스팔트 함량을 구하고, 결정된 최적아스팔트 함량으로 마샬공시체(S=10 cm)와 자이레토리 공시체(S=15cm)를 제작하여 마샬안정도시험, 휠 트랙킹 시험, 개발된 김테스트(Kim -test)를 수행하였다. 김테스트는 공시체와 하중봉을 지지할 수 있는 김시험장치(Kim tester)를 이용하여 하단이 반경(r) 0.5 또는 1.0cm로 원형절삭한 직경(D) 3cm, 4cm의 하중봉을 사용한다. 또한 재하는 마샬 하중재하 장치를 사용하여 공시체를 60℃ 수조에 30분동안 수침시킨 후 실시되었다. 정하중은 공시체의 직경방향이 아닌 축 방향으로 50 mm/min가 가해졌고, 최대하중(P_max)과 수직변형(y)이 측정되었다. 마샬안정도시험과 간접인장강도시험에서 얻어지는 것과 유사한 곡선이 각각의 시험에서 얻어졌다. 강도값은 P_max, r, y 및 H(=D-2r)을 이용한 K_D=4P_max/π(H+2√(2ry-y^2))^2식을 통하여 계산하였고, 이를 변형강도(kgf/㎠)로 정의하였다. 실험결과, 공시체 직경이나 골재종류보다는 하중봉과 하중봉 하단의 원형처리 여부가 K_D와 P_max 값에 영향을 미치는 것으로 나타났다. 통계분석결과에서 K_D가 소성변형 깊이와 동적 안정도에 높은 상관성을 보였다. 향후 연구를 통해 K_D의 유효성이 검증된다면, Kim-test는 아스팔트 혼합물의 소성변형 저항성을 판단할 수 있는 시험방법으로 사용될 수 있을 것이다. This study dealt with developing a new approach for finding properties which might represent rut resistance characteristics of asphalt mixture under static loading. Two aggregates, a normal asphalt (pen 60-70) and 5 PMAs were used in preparation of 12 dense-grade mixtures. Marshall mix design was used in determination of the optimum asphalt content (OAC) and each mixture at the OAC was prepared for a newly-developed Kim test on Marshall specimen (S=10 cm) and gyratory specimen (S=15cm), and for wheel tracking test. Kim test used Marshall loading frame and the specimen was conditioned for 30min at 60℃ before loading through Kim tester, and apparatus consisting of a loading column and a specimen and column holder. Diameter (D) of column was 3cm and 4cm with each column having different radius (r) of round cut at the bottom. The static load was applied at 50mm/min in axial direction of the specimen, not in diameteral direction, and the maximum load (P_max) and vertical deformation (y) at the maximum load point were measured. A curve, similar to the one from a Marshall test or static indirect tensile strength test was obtained from each test. A strength value was calculated based on the P_max, H(=D-2r). r and y by using the equation K_D=4P_max/π(H+2√(2ry-y^2))^2 and is defined as deformation strength (kgf/㎠). The values of P_max/y and K_I=K-D/y were also calculated to see if these have any correlation with rutting. In general, D and r were significant factors affecting K_D, while specimen size was not. The statistical analyses results showed the K_D had the best correlation with rut depth and dynamic stability. The next best correlation was found from P_max which was followed by P_max/y and K_I in order. Therefore, K_D can be used for selecting the highly resistable asphalt mixture against permanent deformation.

삽목시기, 삽상온도 및 생장조절제처리가 낙우송의 발근에 미치는 영향

김홍열,박정주,이영주,고재철 대구효성가톨릭대학교 응용과학연구소 1997 응용과학연구논문집 Vol.6 No.1

낙우송의 경삽시 발근 및 캘루스형성에 미치는 삽수채취시기, 삽상온도 및 여러 가지 생장조절물질의 효과에 대하여 조사하였다. 4월 3일, 4월10일, 4월 17일, 5월 22월에 삽수를 채취하여 발근 및 캘루스형성에 미치는 영향을 조사한 결과 발근은 4월 17일이 가장 좋았으며 그 다음이 4월 10일 이였다. 캘루스형성율의 경우 4월 17일이 가장 좋았으며 다음이 5월 22일 이였다. 삽상온도는 삽수채취시기에 관계없이 20℃가 발근 및 캘루스 형성에 가장 효과적이었다. NAA, IAA, S-07처리에 의해서 캘루스형성이 촉진되었다. This experiment was carried out to evaluate the effects of cutting date, bed temperature and growth regulators on the rooting of stem cuttings of Taxodium distichum (L.) Rich. As a result of investigation for the rooting and callus formation of stem cuttings which were cutted at 3, 10, 17 April and 22 May respectively, rooting cutted at 17 April was best and 10 April in the next. And callus formation rate was highest at 17 April and 22 May in the next. Under 20℃ bed temperature, rooting and callus formation were better than 30℃ regardless of cutting dates. Callus formation was promoted by NAA, IAA, and uniconazole treatments.

상악 제2대구치를 발거하고 치료한 성장기Ⅱ급 부정교합 환자의 치료전 특성

김재형,김정일,임용규,이동렬 대한치과교정학회 2005 대한치과교정학회지 Vol.35 No.3

본 연구의 목적은 성장기 Ⅱ급 부정교합 환자에서 상악 제2대구치를 발거하고 치료한 증례와 비발거로 치료한증례 중 비교적 양호한 결과를 얻은 증례들을 후향적으로 관찰하여 두 군 간의 치료 전 측모 두부방사선 사진 상에서 골격성, 치성, 연조직 특성을 비교하고자 하였다. Ⅱ급 구치 및 견치관계를 보이고 7 mm 이하의 수평피개, 중등도 이하의 총생을 갖는 51명의 환자를 18명의 상악 제2대구치 발거 치료군화 53명의 비발거 치료군으로 분류하여 비교하였다. 두 군 간의 비교는 t-검정법으로 시행하였고 판분석을 통해 두 군을 판별해 주는 주요 항목들을 알아보았으며 다음과 같은 결론을 얻었다. 골격성 특성 중, 전후방적인 계측 항목에서는 유회성 있는 차이를 보이는 항목은 없었으며 AB-MP (˚). Na-Me (mm), AVD (anterior vertical dimension, mm) 와 같은 수직적 계측항목에서만 유의성 있는 차이를 보였다 (p〈 0.05). 치성 특성 중에서는 상하악 제1대구치의 위치 및 경사도와 관련된 항목 윗 상악 제3대구치의 경사도에서 유의성 있는 차이를 보였으며 특히 발거군에서 상악 제1대구치의교합평면 및 FH 평면에 대한 근심경사도가 더 컸다. 두 군 간에 유의성 있는 차이를 보이는 계측 항목들(U8-FH(˚)는 제외)을 이용하여 발거군과 상악 제3대구제가 양호했던 비발거 증례군에 대해 증감 판별분석을 시행하였으며 그 결과 양군을 판별하는데 기여도가 높은 항목은 U6-VRL (mm), AB-MP (˚) 으로 나타났다. 이 두 항목으로 이루어진 판별식을 도출한 바 본 연구에 이용된 발거군과 비발거군 증례들의 78.4%를 정확히 분류해 낼 수 있었다. 또한 본 연구에 사용된 모든 계측 항목들(U8-FH (˚) 는 제외)을 이용하여 발거군과 비발거군에 대해 증감 판별분석을 시행한 결과 U6-VRL (mm), AB-MP (˚), 그리고 U7-FH (˚) 가 양 군을 분별하는데 유의성이 있었고 이 세 항목들을 이용한 판별식을 통해서 89.2%를 정확히 분류해 낼 수 있었다 The purpose of this retrospective study was to estimate the pretreatment characteristics of growing patients with Class II malocclusion, who had been treated with maxillary second molar extractions. The sample comprised of 51 subjects. 18 subjects were classified into the molar extraction group, and 33 subjects were treated without extraction and classified into the nonextraction group. Pretreatment lateral cephalograms were calculated and analyzed by independent t-test and stepwise discriminant analysis. In measurements for skeletal pattern, no anteroposterior measurements and proportions of various vertical dimensions were significantly different, and only some measurements such as AB-MP (°), Na-Me (mm), AVD (mm) were significantly different between the two treatment groups (p ( 0.05). In measurements for dentoalveolar pattern, some measurements, which were related to the position and angulation of the upper and lower permanent first molars, and the angulation of the upper third molars, were significantly different between the two treatment groups. In particular, the maxillary second molar extraction group exhibited more mesial angulation of maxillary first molar to the occlusal plane.

약물전달체를 위한 폴리에틸렌글리콜과 폴리카프로락톤을 이용한 나노입자

김태형,채수영,최창용,김동곤,김명열,나재운 한국공업화학회 2004 응용화학 Vol.8 No.2

The self-aggregation behavior and microscopic characteristics of the PEG-b-PCL copolymer self-aggregates, prepared by solvent evaporation method, were investigated by `H NMR, dynamic light scattering (DLS), and fluorescence spectroscopy. The PEG-PCL block copolymer formed nano-sized self-aggregates in an aqueous environment by intraand/or intermolecular association between hydrophobic PCL chains. Then, drug loading and its release behavior of clonazepam loaded PEG-b-PCL nanoparticles were investigated. The result revealed that hydrophobic-hydrophilic balances played a crucial role for drug loading and its release behaviors.

NaCl-KCl 혼합 수용액에서의 기체체류량과 물질전달계수에 관한 연구

金相烈,朴東源,崔載旭,韓相玉 동아대학교 공과대학 부설 한국자원개발연구소 1990 硏究報告 Vol.14 No.2

Gas Holdup and mass transfer coefficient were measured and the effect of activity coefficeent and gas velocity on them was studied. Gas holdup increased as the gas velocity increased, and decreased as the concentration of aqueous solutions of NaCl-KCl increased Mass transfer coefficient increased as the gas velocity increased, and decreased as the concentration of aqueous solutions if NaCl-KCl increased. Correlation equation between the gas holdup and mass transfer coefficient, and the various factors is shows a good agreement with experimental values.

스테로이드 주사를 이용한 이개혈종의 치료

박재율,신승헌,김광훈,이웅렬,박일동,박광헌,마도훈,전일훈 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.2

쇄골두개이골증의 증례 : a case report

김재덕,이창율,유충현 大韓口腔顎顔面 放射線學會 2004 Imaging Science in Dentistry Vol.34 No.1

Cleidocranial dysplasia is a rare and autosomal dominent disorder characterized by aplasia or hypoplasia of the clavicles, an open fontanelle, dental abnormalities, and short stature. A 17-year-old female who presented with short stature and subsequent delay in eruption of permanent teeth is described. she showed the abnormal hypermobility of the shoulder, ocular hypertelorism and concave nasal bridge. Radiographs revealed the underdeveloped maxilla, defect of the cranium in the fontanelle region, and aplasia of the clavicles. Characteristically, panoramic view revealed near parallel-sided borders of the ascending ramus and downward curvature of the zygomatic arch with hypoplasia. The prolonged retention of deciduous teeth with delayed eruption of permanent teeth and multiple embedded supernumerary teeth were striking. Radiographic and clinical investigations revealed Cleidocranial dysplasia.

PVA 복합체의 표면 성분과 구조 : PVA/Gelatin/Borax film PVA/Gelatin/Borax 필름

김재문,오준,김명렬,O'Donell, James H.,Jill, David J.,Pomery, P.J. 順天大學校 1999 論文集 Vol.18 No.1

Surface composition and structure of PVA complexes (PVA/Gelatin/Borax) films were investigated with XPS and the bulk content was measured with ¹H-Neuclear Magnetic Resornance spectrometry (¹H-NMR). From this results, it is possible to calculate of carbon, oxgen, nitrogen, etc and showed hydroxyl and aminogroups. Crystallinities of PVA was measured by infrared and X-ray diffractometer. On the basis of the experimental results, the structure to the PVA complexes in various materials were estimated. PVA complexes have a uniform structure with flexible PVA chains in a mixed solvent of water.

디지탈영상에서 골판톰의 프랙탈분석

김재덕,김진수,이창율 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.1

Purpose : (1) To analyse the effect of exposure time, ROI size and one impact factor in the image processing procedure on estimates of fractal dimension; and (2) to analyse the correlated relationship between the fractal dimension and the Cu-Eq value (bone density). Materials and Methods : The cylindric bone phantoms of 6 large and 5 small diameter having different bone densities respectively and human dry mandible segment with copper step wedge were radiographed at 1.0 and 1.2 sec esposure (70 kVp, 7 mA) using one occlusal film and digitized. Eleven rectangular ROIs from 11 cylindric bone phantoms and 4 rectan-gular ROIs from cortical, middle, periodontal regions, and socket of bone were selected. Gaussian blurred Image was subtracted from original image of each ROI and multiplied respectively by 1, 0.8, and 0.5, and then the image was made binary, eroded and dilated once, and skeletonized. The fractal dimension was calculated by means of a box counting method in the software ImageJ. Results : The fractal dimension was decreased gradually with continued bone density decrease showing strong correlations (bone phantom; r>0.87, bone; r>0.68) under 70 kVp 1.0 sec M = 0.8. Fractal dimensions showed the significant differerence (p<0.05) between two different exposure times on the same small ROI of bone phantom. Fractal dimensions between two different sizes of ROI on bone phantom showed the significant differerence (p<0.05) under 1.2 sec exposure, but did not show it (p>0.05) under 1.0 sec exposure. Conclusions : Exposure time, ROI size, and modifying factor during subtracting could become impacting on the results of fractal dimension. Fractal analysis with thoroughly evaluated method considering the various impacting factors on the results could be useful in assessing the bone density in dental radiography.

Validation Study of Kim's Smoking Cessation Motivation Scale and Its Predictive Implications for Smoking Cessation

Park, Jae Woo,Chai, Sukhi,Lee, Ju Yul,Joe, Keun-Ho,Jung, Jo Eun,Kim, Dai Jin Korean Neuropsychiatric Association 2009 PSYCHIATRY INVESTIGATION Vol.6 No.4

<P><B>Objective</B></P><P>The purpose of this study was to develop a scale to measure motivation for smoking cessation. Motivation is known to be important for success of smoking cessation. The reliability of the scale was assessed and its predictive validity for smoking cessation was evaluated.</P><P><B>Methods</B></P><P>We recruited 333 men aged 20 to 70 that visited smoking cessation clinics at seven public health centers. The demographic characteristics were recorded and the Korean version of Stages of Readiness for Change and Eagerness for Treatment Scale for Smoking (K-SO-CRATES-S) performed. A smoking cessation motivation scale was developed with 10 questions based on the theory of motivation enhancement therapy.</P><P><B>Results</B></P><P>The motivation scale was composed of four subscales based on the factor analysis; each subscale had an adequate degree of internal consistency. In addition, the newly developed scale had a high degree of validity based on its significant correlation with the smoking version of SOCRATES. Moreover, the precontemplation level of motivation was found to significantly predict the success of smoking cessation. And one of the subscales of the Korean Nicotine Dependence Syndrome Scale (K-NDSS), stereotypy which also significantly predicted the success of smoking cessation, significantly correlated with the preparation 1 and 2 level of motivation.</P><P><B>Conclusion</B></P><P>The smoking cessation motivation scale with 10 questions that was developed in this study was a highly reliable and valid scale for the prediction of success for smoking cessation for those who wanted to stop smoking.</P>