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.

골분을 이용한 구리 흡착 첨착

김은정,박정훈,김정섭,유현철,이봉섭,곽명화,우성훈,박승조 東亞大學校 環境問題硏究所 2005 硏究報告 Vol.27 No.1

Spent pig bone was consist of hydroxyapatite. And then we thought that it have a possibility as a adsorbent. The preparation of bone char prepared from spent pig bone in this study. We study on the recycling possibility as a adsorbent is able to adsorb copper ion from their single aqueous solutions. The results are summarized as follows. Bone char that prepared from spent pig bone at 105, 400, 700℃. The adsorption removal efficiency of copper ion onto bone char as adsorbent was above 90% for 15 hours. Increase in the initial pH of the copper ion solution result in an increase in the copper ion uptake per unit weight of the adsorbent. Freundlich isotherm model was found to be applicable for the experiment data of copper ion. The results showed that spent pig bone can be used for the absorption of the copper ion.

한국어 학습자의 연결 어미 오류 양상에 관한 연구 : 언어권별 오류 양상을 중심으로 Focused on the error analysis different mother tongue

김중섭 국제한국어교육학회 2002 한국어 교육 Vol.13 No.2

Jung-Sup Kim. 2002. A Research for the Korean Learners' errors in the connecting ending words - Focused on the error analysis different mother tongue. Journal of Korean Language Education 13-2: 87∼109. The errors of learners are inevitable components in the course of learning a second language. These have been the main concern of the researchers and the teachers for a long time. The early research noted that the errors were negative, but gradually the researchers recognized that they were natural part of language learning process. The research for errors can be the basis of understanding the process of learning target language, and it will give a clue to prepare a proper contents and teaching methods. Also it can provide learner-centered teaching methods and communicative methods in the Korean language education. This research studied that the aspect of the Korean language connecting ending words with subjects who speak Japanese, Chinese, English, Russian and several different language speakers as their mother tongue, examining their writing samples and in their writing and recorded speech data. As a result, the frequent errors the subjects made were not influenced by their first language. But the subjects simply substitute similar words which they think the meanings are the same. Furthermore, the research found that substituting similar connecting ending words was the result of misunderstanding of the meaning between the two simple sentences when the subjects combined them. Therefore, the teachers have to pay more attention to understand the learners' errors. The research on the errors throughout analyzing the writing, recorded speech data and other objective materials will make it possible to teach Korean language systematically and efficiently. And this research would be a basis to realize a learner-centered education by adapting it in the fields of developing text, syllabus design, and preparing standard of evaluation. (Kyunghee University)

Suppressive effects of three diketopiperzines from marine-derived bacteria on TGFBIp-mediated septic responese in human endothelial cells and mice

( Byeongjin Jung ),( Sae Kwang Ku ),( Ming Gao ),( Kyung Min Kim ),( Min Su Han ),( Hyukjae Choi ),( Jong Sup Bae ) 영남대학교 약품개발연구소 2016 영남대학교 약품개발연구소 연구업적집 Vol.26 No.-

Diketopiperazine is a naturally occurring cyclic dipeptide found from diverse living organisma. The com-pounds in this structure class have been known with a broad spectrum of bioactivities including anti-inflamma-tory activities. Transforming growth factor β-induced protein (TGFBIp) is an extracellular matrix protein whose expression in several cell types is greatly increased by TGB- β. TGFBIp is released by human umbilical vein endothelica cells and functions as a mediator of experi-mental sepsis. Here, three (1-3) of diketopiperazines were isolated from two strains of marine-derived bacteria and we hypothesized that 1-3 could reduce TGFBIp-mediated severe inflammatory responses in human endothelial cells and mice. Here, we investigated the anti-septic effects and underlying mechanisms of 1-3 effectively inhibited lipopolysac-charide-induced release of TGFBIp and suppressed TGFBIp-mediated septic responses. In addition, 1-3 sup-pressed cecal ligation and puncture (CLP)-induced sepsis lethality and pulmonary injury. In conclusion, 1-3 sup-pressed TGFBIp-mediated and CLP-induced septic response. Therefore, 1-3 could be a potential therapeutic agent for treatment of various severe vascular inflamma-tory diseases inhibition of the TGFBIp signaling pathway.

토양처리용 천연물제초제 개발을 위한 생물검정법 개선

김재덕(Jae Deong Kim),황현진(Hyun Jin Hwang),서보람(Bo Ram Seo),최정섭(Jung Sup Choi),김진석(Jin Seog Kim) 韓國雜草學會 2011 Weed&Turfgrass Science Vol.31 No.3

본 연구는 토양처리용 천연물 제초제의 개발을 보다 신속하게 효율적으로 진행하기 위한 방안으로서 실용적인 입장에서 보다 개선된 검정법을 확립하기 위해 수행되었다. 검정하고자 하는 화합물의 량이 50㎎ 이상 충분할 경우, 잡초 4초종(피, 바랭이, 자귀풀, 어저귀)이 파종된 50㎠ 토양 표면적을 가진 폿트에서 온실검정을 함으로서 기존의 방법(토양 표면적이 350㎠인 폿트 이용)에 비해 약제 소요량을 78배 줄일 수 있었다. 이때 검정초기 처리농도는 10,000㎍ mL<;SUP>;-1<;/SUP>; 내외로 하는 것이 적당하였다. 한편 검정용 시료의 량이 10㎎ 이하로서 미량일 경우는 6 well plate를 이용하되 각 well에 밭토양을 담고 4가지 초종을 파종한 다음 실내에서 제초활성을 검정하는 방법이 추천될 수 있었다. 이는 기존의 방법(토양 표면적이 350㎠인 폿트 이용)에 비해 약제 소요량 및 처리용액 부피를 14배 가까이 줄일 수 있었고 실제에 가까운 데이터를 확보할 수 있어 보다 빠른 속도로 천연물 제초제를 개발하는데 도움이 될 것으로 판단되었다. This study was carried out to establish an improved bioassay system on the side of practicality, pre-emergence bioassay which is more effective in developing soil application natural herbicides. A miniaturized method which have a 50 cm² of soil surface area and was efficient by 7 times compared to the existing soil application assay (350 cm² of soil surface area) was established, in which four weed species (Echinochloa crus-galli, Digitaria sanguinalis, Aeschynomene indica, and Abutilon theophrasti) were planted and grown in greenhouse. This would be applicable when the amount of screening compound is much more than 50 mg. The initial application rate was desirable at 10,000 μg mL-1. On the other hand, the 6 well plate assay which has 4 weed species in each well containing upland soil and could be conducted in growth chamber, was established. This assay was resulted in minimizing in level of 1/14 test volume and 1/14 amounts of test compound to the conventional method that has been used for screening of synthetic compounds in KRICT, and applicable for the small amount of test compound (less than 10 mg). Therefore, the improved bioassays established in this study would be helpful for a rapid and efficient development of soil application natural herbicides.

딤플을 적용한 평판에 대한 항력 감소 연구

백부근(Bu-Geun Paik),편영식(Young-Sik Pyun),김준형(Jun-Hyung Kim),김경열(Kyung-Youl Kim),김기섭(Kim1 ?Ki-Sup),정철민(Chul-Min Jung),김찬기(Chan-Ki Kim) 대한조선학회 2012 大韓造船學會 論文集 Vol.49 No.4

박막 크로멜-알루멜 열전퇴형 교류-직류 변환기

정인식,김호운,김진섭,이정희,이종현,신장규,박세일,권성원 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

A planar chromel-alumel multijunction ac-dc converter was fabricated on a LPCVD Si_(3)N_(4)/SiO_(2)/Si_(3)N_(4)-diaphragm, prepared by silicon bulk micromachining, which thermally isolated a bifilar evanohm-heater and the hot junctions of a chromel-alumel thermopile from the silicon substrate. The voltage responsivity, the ac-dc transfer error, and the fluctuation of the output thermoelectric voltage of the converter were investigated. The respective voltage responsivities in air and in a vacuum of the converter were about 3.16 mV/mW and 9.41 mV/mW. The ac-dc voltage and the current transfer errors in air were about ±1.5 ppm and ±0.7 ppm in a frequency range from 10 Hz to 10 kHz, respectively. The fluctuation of the output thermoelectric voltage from 5 seconds to 120 seconds after preheating in air for 5 seconds was about 0.06 % for a heater input of dc 1 V.

GIS를 이용한 아파트단지 통신장애의 시뮬레이션

김진택,엄정섭 경북대학교 사회과학대학 지리학과 2005 地理學論究 Vol.- No.24

기존의 전파 장애 예측 모델은 대부분이 외국의 학자들에 의해 개발되었고 2차원 특성을 지니고 있어 한국의 전형적인 지형에 적용하는 데 많은 한계를 가지고 있었다. 기존의 모델에서는 아파트 단지가 전파의 확산의 관점에서 영향을 미치는 독립적인 공간객체로 다루어지지 않았다. 재난 재해 등의 긴급상황에서 아파트 지역에서 교신 장애가 발생할 경우 문제의 원인을 규명하여 대처방안을 마련하는 데 상당한 한계가 있었다. 본 연구에서는 3차원 GIS와 가상현실의 기법에 의거하여 아파트의 배치형태 등 공간 특성을 반영한 한국의 전형적인 도시에서 발생하는 전파 장애에 대한 예측모델을 개발하였다. 본 연구결과는 아파트 건설 당시 전파 장애의 문제를 근본적으로 제거할 수 있는 배치형태를 결정하는 데 도움을 줄 수 있을 것이며 전파 기지국의 배치나 전파 장애지역의 해소 방안을 마련하는 데 중요한 참고자료가 될 수 있을 것으로 사료된다. Existing radio-wave prediction models do not accomodate Korean topographic elements as well as three-dimensional techniques, because they're developed by two-dimensional approach with various natural and artificial features based on foreign landform. At the model, apartment complex is treated as each general building and not classified by a propagation environment. Consequently, it has limitations for radio-wave operators to make correct decision with existing prediction models of radio-wave, which don't fit wireless network construction and application within the country. To solve these limitations, the apartment's radio-wave path loss model(GARP) was developed by simulating the typical Korean urban environment in GIS three-dimension virtual space. It can be used the apartments' construction, and collecting basic information about the Radio-wave environment to make an impact evaluation. By using the GARP model and mapping a value of wave path loss on real topographical space with GIS visibility, this study will ultimately contribute operators to deciding that design of a wireless service region, judgment about a shadow area of radio-wave, location selecting of the best suited base station or repeater station.

고령토로부터 합성한 제올라이트 A 의 열처리에 의한 특성변화

김면섭,정순용 한국화학공학회 1984 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.22 No.1

하동지방의 담홍색 고령토를 수산화나트륨수용액으로 반응시켜 합성한 제올라이트A를 400℃에서 900℃까지 열처리하여 그 특성변화와 이온교환성에 대해서 연구하여 다음과 같은 결과를 얻었다. 제올라이트A는 800℃에서 결정이 파괴되어 900℃에서는 nepheline이 생성됨을 알았다. 400℃와 750℃사이에서 열처리한 제올라이트A의 흡수성은 변화가 없었으나, 800℃ 및 900℃로 열처리한 제올라이트A는 흡수능이 거의 없음을 알 수 있었다. Ag^+ - Na^+의 이온교환반응의 경우는 400∼750℃로 열처리하나 제올라이트A는 이온교환성이 거의 일정하였으나 Mg^(2+) - Na^+의 이온교환반응일 경우에는 400℃에서 750℃까지 열처리온도가 증가할수록 이온교환성이 조금씩 감소하는 경향을 보였다. 또한 800℃ 및 900℃로 열처리한 제올라이트A는 이온교환이 거의 일어나지 않음을 알 수 있었다. Ag^+ - Na^+와 Mg^(2+) - Na^+의 이온교환반응의 실험값으로부터 표준 Gibbs자유에너지, 엔탈피, 엔트로피를 계산하였다. Synthetic zeolite A prepared from Hadong kaolin in sodium hydroxide solution was calcined between 400 and 900℃. Changes of ion exchange properties and structure during the thermal treatment between 400 and 900℃ were studied. As the synthesized zeolite A was treated at 800℃, the structure was partially destroyed, whereas at 900℃, nepheline type structure was appeared. The water adsorption capacity on zeolite A treated between 400 and 750℃ was almost constant, but that was only trace amount at 800 and 900℃. When zeolite A was heated from 400 to 750℃, the ion exchange properties were almost constant for the Ag^+-Na^+ system, but slowly decreased for the Mg^(2+)-Na^+ system. At 800 or 900℃, the ion exchange properties were negligible. From the experimental data at ion exchange reaction in the cation system of Ag^+-Na^+and Mg^(2+)-Na^+ Gibbs free energy, enthalph, and entropy were calculated.

미니에멀젼 중합을 이용한 상전이 물질의 나노 캡슐화 및 열적특성 연구

김경래,백경현,신진섭,김중현 한국공업화학회 2004 응용화학 Vol.8 No.2

The nanocapsule containing phase change materials (PCM) such as octadecane were prepare by miniemulsion polymerization. The size, shape, and encapsulation efficiency of PCM nanocapsule was analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), hydrodynamic fractionation (CHDF), differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). PCM nanocapsule size range from 50 to 100 ㎚, and its morphology was shapes. The maximum encapsulation efficiency of PCM materials were around 90%.