내후성 폴리머 콘크리트의 제조 및 특성연구

연규석,김기성,이기원,황진하 강원대학교 석재복합신소재제품연구센터 2001 석재연 논문집 Vol.6 No.-

본 연구에서는 불포화 폴리에스터 수지비율을 변수로 하는 자외선 흡수제 첨가유ㆍ무 시편에 대한 Xenon lamp, 52±3℃, 실내습도 50±5%, 시험체 걸이 직경 20inches의 조건의 내후성 시험기로 각각 100, 200, 400, 800, 1600 시간 인공촉진열화 시킨 시편의 색차변화를 측정하여 불포화 폴리에서터 수지량 및 자외선 흡수제의 첨가에 의한 열화특성을 고찰하였다. 그 결과 100% 불포화 폴리에스터 수지량 및 자외선 흡수제의 첨가에 의한 열화특성을 고찰하였다. 그 결과 100% 불포화 폴리에스터 수지 시편과 상대적으로 수지비율이 큰 폴리머 페이스트에서는 자외선 조사시간에 따른 큰 색차변화 및 자외선 첨가에 의한 열화방지 효과를 확인 할 수 있었고 불포화 폴리에스터 수지비율이 상대적으로 작은 폴리머 모르타르에서는 자외선 조사에 의한 색차변화 및 자외선 흡수제 첨가에 의한 열화방지가 그리 크지 않음을 확인할 수 있었다. 이러한 것은 야외에 설치되는 폴리머 모르타르(콘크리트) 제품은 자외선에 의한 열화가 그리 크지 않음을 보여주는 결과이기도 하다. This study was to investigate the characteristics of deterioration of polymer concrete due to wethering Two sets of specimens with a various mixing ratio of unsaturated polyester resin, UV absorber added and not-added, were artificially exposed by the weathering test machine to ultraviolet (UV) radiation 100, 200, 400, 800 and 1600 hours under the conditions that the temperature was set by Xenon lamp at 52±3℃, the chamber humidity at 50±5%, and specimen rack diameter 20 inches to measure the color change to examine the characteristics of deterioration. Color difference increased as the exposure time to UV radiation increased, but decreased 20-30%, comparing to the case of non-absorber added, as the ultraviolet absorber was added. On the other hand, the effect of addition of ultraviolet absorber decreased as addition of aggregate increase. Thus, the effect of addition of ultraviolet absorber was a little on the polymer concrete containing aggregate, Especially, increment of color difference in polymer mortar specimen was lower than that of polymer resin and polymer paste specimen, when the resin volume for specimen mixture proportion was below 30%, as fine aggregate increased. As a result, outdoor-installed polymer concrete product is believed to be hardly affected by ultraviolet radiation.

Polystyrene Beads를 사용한 경량 폴리머 시멘트 모르타르의 기초적 성질

연규석,신영수,이윤수,이기원,황진하 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

polystyrene beads를 사용한 경량 시멘트 모르타르의 성질을 개선하기 위해 EVA혼화용 폴리머를 첨가한 모르타르를 제조하여, 물리ㆍ역학적 성질을 살펴보았던 바 polystyrene beads 골재 재부의 공극 때문에 높은 공기량을 보였고, 플로우 값은 폴리머-시멘트비 10%에서 가장 높은 값을 나타냈다. 또한 폴리머-시멘트비가 증가할수록 압축강도와 휨강도는 증가하였고, 시멘트-경량골재비가 낮을수록 압축강도는 증가하였으나, 휨감도에는 크게 영향을 주지 않았다. The objective of this study was to improve performance of lightweight polymer cement mortars by treating with redispersible polymer powders. Lightweight polymer-cement mortars were prepared with respect to different polymer-cement ratios, and tested for water absorption, specific gravity, flexural and compressive strengths, workability and freeze-thaw resistance. Manufactured lightweight polymer-cement mortars in this study showed lower specific gravity and lower thermal diffuseness than ordinary cement mortars. Water absorption, specific gravity, flexural, compressive strengths and workability were measured according to appropriate KS test methods. As a results, the optimum mix ratios for cement-aggregate, polymer-cement, and water-cement were found to be 1:3, 10% and 30%, respectively.

저수축형 폴리머 콘크리트의 제조 및 물리·역학적 특성

연규석,이윤수,최동순,정경현,황진하 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

본 연구에서는 폴리머 콘크리트의 수축저감을 목적으로 수지량, 수축저감제함량과 S/a 비등을 변화시켜 경화수축의 변화와 강도 특성을 실험적으로 구명하였다. 경화수축량은 수치량이 105%일 때 보다 11.5%일 때, 즉 수지량이 증가할수록 커짐을 알 수 있었다. 수축저감제의 첨가에 따른 경화수축량은 감소함을 알 수 있었다. B10.5-SR10일 경우 수축저감제가 첨가되지 않았을 때 보다 약 30%, B10.5-SR20 일 경우 약 53%, B11.5-SR10일 경우 약 31%, B11.5-SR20 일 경우 약 47% 정도의 수축저감의 효과를 볼 수 있었다. S/a 비에 따른 경화 수축챨ㅇ은 S/a 60일 때 가장 적은 값을 보였으며, S/a 50, S/a 40 일때는 S/a60 일 때 가장 적은 값을 보였으며, S/a 50, S/a 40일 때는 S/a 60일 때 보다 각각 10%, 30% 정도 수축량이 증가함을 알 수 있었다. 압축 및 휨 강도특성은 수지량이 증가할수록 높아지고, 수축저감제의 첨가량이 증가할수록 낮아짐을 알 수 있었다. S/a 비에 따른 강도 특성은 압축강도와 휨강도 모두 S/a 비가 60일 때 가장 큰 값을 보였으며, S/a 비가 50,40 순으로 감소하였다. Many different polymer based concrete materials are known today, but the large setting or hardening shrinkage of polymer concrete is a problem to overcome in their practical applications. The setting shrinkage reaches about five to ten times the drying shrinkage of ordinary cement concrete, i.e, 50 to 60 ×10^4. This paper deals with a reduction in the hardening shrinkage of unsaturated polyester resin concrete which is treated with respect to shrinkage-reducing agent content, S/a ratio and catalyst content, and tested for length change during hardening, and flexural and compressive strengths. It is shown that the change of shrinkage-reducing agent content and S/a ration the length change of the unsaturated polyester resin concrete during hardening.

비정질 Fe1-x Px합금의 전기비저항

문영모, 연규황, 김택기 忠北大學校部設基礎科學硏究所 1987 自然科學硏究 Vol.1 No.1

-본문참고-

還魂散(內消散) 물 엑스 및 20% 에탄올 엑스의 消炎, 鎭痛, 抗菌作用에 관한 硏究

金鍾翰,黃忠演,林圭庠 圓光大學校 韓醫學硏究所 1994 원광한의학 Vol.4 No.1

These experiments were conducted to investigate the anti-inflammatory, analgesic and anti-bacterial activity of Hwanhonsan(HHS) water ext. and 20% EtOH ext. The results were summarized as follows ; The inhibitory effect on the leakage of evans blue into peritoneal cavity was significantly increased by HHS water ext. and EtOH ext, respectively. The paper disk granuloma formation displayed more potent effcet than the control group in EtOH ext. Mouse paw edema induced by histamine was significantly decreased by HHS water ext. and EtOH ext. HHS water ext. and EtOH ext. inhibited the protein exudation in rats. The analgesic activity on 0.7% acetic acid induced writhing syndrome was significantly shown by EtOH ext. Anti-bacterial activity was shown by HHS water ext. and EtOH ext., respectively.

AR기법을 이용한 SLAM 영상 개선

김현,송대건,황기환,연규헌,전계석 慶熙大學校 大學院 1998 高凰論集 Vol.22 No.-

In this paper, we have been studied the enhancement of SLAM image using average response methos. AR methos has been used to reduce the random noise in signal processing. In this the experiment, we have constructed the SLAM system of 10㎒ operating frequency and experienced for holed Al sample. In this experimental result, we have been found that SLAM using AR method was able to get the high-speed and enhanced image compared with SAM.

성인에서 Haemophilus influenzae 감염증의 임상양상과 미생물학적 특성

이종섭,황병연,정희진,김우주,박승철,이도현,이창규,신종희,황규잠,이영희 대한화학요법학회 2000 대한화학요법학회지 Vol.18 No.2

목적 : H. influenzae는 성인에서 흔히 호흡기 감염을 일으키는 균주로, 최근 ampicillin 내성 β-lactamase 생성 균주들이 지속적인 증가를 보이고 있어, 이에 국내 성인에서 H. influenzae에 의한 감염의 임상양상과 분리된 균주들의 미생물학적 특성을 조사하고자 하였다. 방법 : 1998년 3월부터 1999년 9월까지 고려대 구로병원에 내원한 환자중에서 H. influenzae가 분리된 68명을 대상으로 임상양상을 조사하고 항균제 감수성 검사를 시행하였다. 분리된 33주에 대해서 혈청형, 생물형, 세포외막 단백분석을 시행하였고, β-lactamase 생성여부에 따른 감염 환자군간 임상상 및 예후의 차이를 비교하였다. 결과 : 환자의 평균연령은 68세였고, 지역사회 획득감염이 전체의 85%를 차지하였다. 폐렴과 기관지염과 같은 하기도 감염이 전체환자의 75%를 차지하였고 분리 검체 역시 객담이 84%로 가장 많았다. 환자의 71%가 기저질환을 가지고 있었으며, 그 중에 만성 폐쇄성 폐질환, 심혈관 질환, 악성종양, 당뇨병이 대부분이었다. 혈청형으로는 nontypeable 형이 68%로 가장 많았고 b형은 한 예도 없었다. β-lactamase 생성율은 63.2%였고, β-lactamase 양성균주의 항균제 내성율이 음성균주에 비하여 높았으나 β-lactamase 생성 여부에 관계없이 cefotaxime, azithromycin, ciprofloxacin에 대하여 100%의 감수성을 나타내었고 cefaclor, cefuroxime에 대해서는 10% 이하의 낮은 내성율을 보여 이들 항균제들이 치료에 효과적일 것으로 사료된다. 세포외막 단백분석에서는 C형과 D형이 전체의 64%로 가장 많았으며, 혈청형과의 유의한 연관성은 보이지 않았다. 결론 : 성인에서 H. influenzae는 주로 만성 기저질환자에서 급성 호흡기감염 또는 만성 폐쇄성 폐질환의 급성 악화를 유발한다. 기존의 보고에 비해 β-lactamase 양성율이 증가하였고, 이에 따른 항균제 내성율도 증가하여 항균제의 선택에 유의하여야 할 것으로 생각된다. 세포외막 단백분석상 특정한 유형의 균주에 의해 감염이 집중적으로 발생하고 있어 향후 역학 조사의 도구로 이용할 수 있겠다. Purpose : H. influenzae is one of the common causative microorganisms of respiratory tract infections in adults. Recently. β-lactamase producing, ampicillin-resistant H. infiuenzae has become worldwide problem as well as in Korea. We studied to investigate the clinical features and microbiologic characteristics of H. infiuenzae infections in adults. Materials & Methods : From March 1998 to September 1999, 68 patients were enrolled in this study. Clinical features of H. infiuenzae infections were investigated, 68 isolates were subjected to the β-lactamase test, and 33 isolates were used for serotyping. biotyping, antibiotic susceptibility and outer membrane protein (OMP) analysis. Results : Mean age of study patients was 68 years-old and the acquisition rate in community was 85%. Pneumonia and bronchitis were the most common type of infection such as 80%, sputum was the most common clinical specimen for H. mQuenzae isolation. 70% of patients had chronic underlying diseases. Non-typeable strains were 68% and β-lactamase producing rate was 63%. There was no difference in the clinical features and prognosis of H. influenzae infection between the β-lactamase positivie and -negative groups. The susceptibility of cefotaxime, azithromycin, and ciprofloxacin was 100% and that of cefaclor, cefuroxime was under 10% in spite of β-lactamase positivity. In OMP analysis, C and D types were dominant (64%). Conclusion : H. influenzae caused acute respiratory infections in adults with chronic underlying disorders. This study shows higher β-lactamase producing rate and antibiotic-resistance rate than that were reported previously. OMP analysis shows that two major types of strains cause clinical infections intensively.

<i>Epilithonimonas ginsengisoli</i> sp. nov., isolated from soil of a ginseng field

Hoang, Van-An,Kim, Yeon-Ju,Ponnuraj, Shree Priya,Nguyen, Ngoc-Lan,Hwang, Kyu-Hyon,Yang, Deok-Chun International Union of Microbiological Societies 2015 International journal of systematic and evolutiona Vol.65 No.1

<P>A novel Gram-staining-negative, rod-shaped bacterium, designated DCY78<SUP>T</SUP>, was isolated from soil of a ginseng field in Yeon-cheon province (38° 04′ 00″ N 126° 57′ 00″ E), Republic of Korea. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain DCY78<SUP>T</SUP> belonged to the genus <I>Epilithonimonas</I> and was most closely related to <I>Epilithonimonas lactis</I> DSM 19921<SUP>T</SUP> (98.5 % sequence similarity) and <I>Epilithonimonas tenax</I> DSM 16811<SUP>T</SUP> (97.8 %). Growth occurred at 10–30 °C with an optimum temperature of 28 °C. The pH range for growth was pH 5.5–8.0. The major polar lipids were found to be phosphatidylethanolamine three unidentified amino lipids and one unidentified polar lipid. The only predominant quinone was MK-6. The major polyamines were <I>sym</I>-homospermidine and spermidine. The major fatty acids were summed feature 3 (comprising C<SUB>16 : 1</SUB>ω6<I>c</I> and/or C<SUB>16 : 1</SUB>ω7<I>c</I>), iso-C<SUB>15 : 0</SUB> and iso-C<SUB>17 : 0</SUB> 3-OH. The DNA G+C content was 37.9 mol%. On the basis of the phenotypic and genotypic analysis, the isolate is classified as representative of a novel species in the genus <I>Epilithonimonas</I>, for which the name <I>Epilithonimonas</I> <I>ginsengisoli</I> is proposed. The type strain is DCY78<SUP>T</SUP> ( = KCTC 32174<SUP>T</SUP> = JCM 19896<SUP>T</SUP>).</P>

벼 육묘기 개발 및 육묘 실용성

박성태,김상열,황동용,홍연규 한국국제농업개발학회 2004 韓國國際農業開發學會誌 Vol.16 No.3

벼 농사에서 기계화가 어려운 육묘를 못자리 없이 간편하고 저비용으로 할 수 있는 육묘기 개발 및 개발 육묘기의 실용성 평가시험 결과를 요약하면 다음과 같다. 1. 개발 조립식 육묘기는 파종상자 치상선반, 플라스틱판, 부직포와 비닐로 만든 보온덮개로 구성되어 있고 35상자 육묘용 육묘기는 규격이 가로 152㎝, 세로 63㎝, 높이 147㎝이며 무게 75㎏이며, 육묘일수에 따라 육묘선반 간격을 간단히 조절할 수 있다. 2. 개발 육묘기를 이용 육묘시 묘소질은 관행 못자리 모와 비슷하고 결주율는 3.2%로 못자리 육묘상자모 2.8%와 거의 같았다. 3. 개발 육묘기는 대당 20만원정도로 기존 자동화 육묘시설 (198평:7,360상자 육묘기준 및 장비에 비하여 시설비가 43% 절감 된다. 4. 육묘 노력시간은 개발 육묘기는 ㏊당 7.9시간으로 자동화 시설육묘 및 못자리 육묘에 비하여 각각 18%, 76%절감 되었다. 5. 물 사용량은 개발 육묘기 이용 육묘는 ㏊당 2.5kl로 자동화 시설육묘 및 못자리 육묘에 비하여 6~8배 절감되었다. Raising seedling in nursery bed needs not only a lots of time but also labor input which are hard especially to the old and lady farmers. On the other hand, construction of seedling raising facilities such as automated seedling raising house also requires a lots of money. To overcome those problems, a simple seedling raising shelf, which is not necessary for preparation of the seedling raising nursery bed, was developed and its feasibility of seedling raising was evaluated. The dimension of the seedling raising shelf has 152㎝ in length by 63㎝ in width with 147㎝ in height. The shelf is composed of 6 to 7 layers of shelf frame, plastic tray for seedling raising, water supply pipes and white polyester cover. The height of a seedling raising shelf can be adjusted to 6 or 7 layers simply by changing the height of plastic pipes. One unit shelf can accomodate 30 to 35 seedling trays which can transplant about 1000 ㎡ rice field. The seedling height and dry weight of rice seedling grown in the shelf-type seedling raising apparatus was not significantly different from those seedlings grown in the conventional nursery bed. Missing hill percent-age of the seedling grown in shelf-type seedling raising apparatus was 4.3% similar to that of nursery bed of 4.3%. The seeding raising shelf has following advantages. The seedling raising shelf reduces cost of the seedling raising facilities by 43%, labor input hour by 18%, irrigation water saving by 83% versus automated the automated seedling raising house and labor saving by 76% and irrigation water saving as much as 6~8 times versus the conventional seedling raising method of nursery bed.

Quantum unitary transformation corresponding to the classical square canonical transformation and its connected quantum systems

Kyu Hwang Yeon,엄정인,홍석경,Thomas F. George 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.3

A quantum operator corresponding to a function of the canonical position multiplied by its canonical momentum raised to the power of a positive integer for an ordering parameter is evaluated. Using the operators, we construct the Schrodinger equations of systems that correspond to classical systems connected by the square canonical transformation. A unitary operator corresponding to a classical canonical transformation is found on the condition that the relations of the quantum expectations values are the same as those in the classical system. Using the unitary operator, we nd the relation between the wave functions of connected systems, and obtain the ordering parameter as 1/4.