RC T형 교각에서 매개변수 해석에 의한 수화열과 건조수축의 균열저감방안

박성규,김기대,전상채 대구대학교 산업기술연구소 2011 産業技術硏究 Vol.22 No.1

Amidst increasingly growing demand for large concrete structure or high strength / high durability concrete in line with economic development, the risk of ydrothermal cracking resulting from hydration heat and drying shrinkage has been on the rise, In fact, thermal stress caused by hydration heat or contraction stress due to drying shrinkage has considerable effect on design or construction of the structure. The cracks in concrete structure spoils the aesthetic aspect of the structure as well as deteriorates the load bearing capacity of the structure, thereby worsening the usability and safety and reducing the service life of the structure eventually. Moreover harmful substances penetrated into the crack causes the rebar to be corroded more rapidly and other numerous problem. In this study, inspection of the urban railway pier structure was performed to check the cracks and in a bid to identify the cause of the cracks, modelling to simulate the field condition was implemented and the temperature distribution and thermal stress variat ion occurred inside and outside the members were estimated using 3D finite element analysis program, MIDAS/FEA and the thermal cracking index was calculated and analyzed.

소아에서 발생한 골수이형성 증후군 2례

홍성진,윤석중,김성우,조형구,오명호,김기혁,이인성 건국대학교 의과학연구소 1996 건국의과학학술지 Vol.5 No.-

Myelodysplastic syndrome(MDS) is a group of acquired conditions characterized by progressive bone marrow failure associated with normocellular or hypercellular bone marrow that cannot be attributed to nutritional deficiency, chronic infection, or other chronic systemic illness, and cannot be reversed by the successful treatment of those conditions. Whereas the cases of secondary MDS occur at all ages, primary MDS is essentially a disease of elderly, though no age group is exempt and predomonant in men. The MDS is fundamentally clonal disorders at the level of the haemopoietic totipotent stem cell. Clinically, they are characterized by varing degrees of peripheral cytopenia(s) with morphological and functional abnormalities of blood elements. We have experienced two unrelated pediatric cases, who showed pancytopenia on admission and the characteristic marrow findings of MDS. The first case, a 12 months-old girl, showed increased reticulin with abnormal localization of immature precursor cells(ALIP) in her bone marrow, in addition to dysplastic features such as bi-and multi-nucleation of late normoblasts and internuclear bridging. She also showed 22% of blasts in her bone marrow cells thus classified in the category of RAEB-t after FAB classification. Also found were a chromosomal abnormality namely 46 XX t(14q21q), which was an unusual one. Her family brought her home and, 4 month later, she deceased. The second case, a 12 year-old boy, showed pancytopenia with Pseudo-Pelger-Huet anomaly in neutrophils but no blasts in the peripheral blood. Bone marrow of this case also showed the picture of dyserythropoiesis with binuclearity, internuclear bridging, nuclear fragments, multinuclearity of late normoblasts, in addition to megaloblastoid change in the normoblasts and increased mitosis in granulocytic series. No chromosomal abnormality was found. Classified as RA after FAB classification of MDS. Showed good response to conservative management for anemia for more than one year.

Actinobacillus actinomycetemcomitans의 Lipopolysaccharide에 대한 단클론항체의 제작 및 특성

성진효,이영종,김동기,장기완 대한구강보건학회 2003 大韓口腔保健學會誌 Vol.27 No.4

Actinobacillus actinomycetemcomitans(A.actinomyceremcomitans), a nonmotile, gram negative facultative anaerobic coccobacillus, is supposed to be an important etiological agent in localized juvenile periodontitis and associated with adult type periodontitis. Lipopolysaccharide(LPS) is one of the various virulent factors of A. actinomycetemcomitans and can directly or indirectly cause destruction of periodontal tissue. The purpose of this study was to produce and characterize the monoclonal antibody to LPS of A.actinomycetemcomitans. The results were as follows; 1. The LPS yield of A. actinomycetemcomitans was 0.7% based on dry cell weight. 2. The antibody titers of immuninzed serum with 5.2 × 10^(8) bacteria were 1:64,000 to whole cells and 1:8,000 to LPS. 3. From three times of cloning the antibody producing hybridomas using limitation dilution method, ten monoclones producing monoclonal antibody to LPS of A.actinomycetemcomitans were obtained. 4. Ten monoclonal antibodies to LPS of A. actinomycetemcomitans were not found to cross-react with LPS of Escherichia coli(E. coli). These results indicate that the monoclonal antibody to LPS of A. actinomycetemcomitans was specific for A. actinomycetemcomitans.

혐기·호기공정을 이용한 생물막법에서 유기물, 질소 및 인제거에 관한 연구

이성기,송영일,김현중,진성기,김은영 조선대학교 환경연구소 2001 環境硏究 Vol.17 No.1

Anoxic and Oxic process with contact media is used to remove an organic matter, nitrogen and phosphorus in sewage which derives from domestic wastewater. Experiments have been done with various conditions that concentration of oxygen can be 3mg/ℓ, 4∼5mg/ℓ and 5∼6mg/ℓ by controlling an retention time can be 10hr, 12hr and 14hr, return rate can be 0%, 100% and 200%. As the concentration of oxygen is 2∼3mg/ℓ. The rate of removal of BOD. COD. SS. T-N and T-P is 87%, 76%, 82%, 34% and 24%. As the concentration of oxygen is 5∼6mg/ℓ. The rate of removal of BOD, COD, SS, T-N and T-P is 92%, 84%, 88%, 45% and 33%. In the rate of removal of an organism, nitrogen and phosphorus thus It well be known that the rate of removal an organic matter, nitrogen and phosphorus will be increased as the concentration of oxygen becomes higher. As th retention time is increased, the rate of removal of BOD, COD, SS, T-N and T-P is gradually higher in the rate of removal of an organic matter, nitrogen and phosphorus. Because contact time and contact area will be increased, which generates active substrate transfer and metabolic react according to increment of retention time. As the return rate is increased. The rate of removal of BOD, COD and SS is likely to be increased. In the case of T-N. It is also increased by 28% at 0% of the return rate and by 60% at 200% of the return rate. In the case of T-P, however, It is deceased, as the return rate is increased by 42% at 0% of the return rate and by 30% at 00% of the return. As the return rate is increased the retention time is decreased, which causes less activity of bacterial which affects that the rate of removal of Phosphorus is decreased.

전기절연유의 절연파괴에 미치는 전극간격 및 곡률반경의 영향

강성화,채홍인,이종필,임기조 한국안전학회 2004 한국안전학회지 Vol.19 No.1

In this paper, we investigated the influence of gap length and tip radius on breakdown of mineral based insulation oil. Applied voltages were DC and AC voltage. Electrode system was needle-plane structure. The tip radius of needle electrode was 5, 10, 20 and 25μm, respectively. We measured breakdown voltage for each of tip radius with increasing electrode gap, 2mm to 12mm. Electric breakdown strength at tip was calculated using Mason's equation contained geometric figure. As gap length increased, breakdown strength increased linearly. But, as tip radius of needle increased, breakdown strength decreased exponentially. It can be explained by the phenomenon that electron is easily injected, as tip radius increases, and effective work function decreases. When appling DC voltage, breakdown strength was higher when polarity of needle was negative than positive. It is because of the space charge effect in accordance with the influence of liquid motion.

BLDC 모터를 이용한 PV 양수 펌프 시스템

최성호,조정민,전기영,김성남,성낙규,김용주,한경희 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

In this paper, we adapted BLDC motor to PV water pumping systems to maintain high efficiency in the wide speed area. Also to design confidence, we adapted the vector control that drive the maximum torque at each speed limit. We designed optimal gain value of current, speed and pressure PI controller. Inverter gate pulse used Space Vector PWM to reduce torque pulsation of BLDC motor. Finally it was improve general matters of high water storage tank method by direct water supply pumping method.

MMX 기술을 이용한 AC-3 복호기 구현

박성오,기창서,정익주 강원대학교 정보통신연구소 2001 정보통신논문지 Vol.5 No.-

The Dolby AC-3 decoder is an audio compression format widely used in DVD and DTV. The AC-3 offers 5 channels, 48KHz and 384Kbps. AC-3 required high performance PC and high performance processing power, Intel's MMXTM technology provides instructions that can significantly speed up the execution of the Dolby AC-3 decoder. This paper describes method of using MMXTM technology.

마이크로파로 가열된 리튬 실리케이트계 무기고분자의 핵 생성 및 결정화에 관한 연구

박성수,박찬영,민성기 釜慶大學校 1999 釜慶大學校 論文集 Vol.4 No.1

A comparison of nucleation and crystallization of amorphous lithium silicate under the conventional and microwave processing was investigated. Optical microscopy(OM). X-ray diffractometry(XRD), and differential thermal analysis(DTA) were used to evaluate the results. Both conventional and microwave heat-treated samples had same nucleation temperature, 460~480℃, and same temperature of maximum nucleation rate, 580℃. From the results of DTA, the probability for the bulk crystallization increased in the microwave heat-treated samples. compared to conventional one. Degree of crystallization increased with increasing crystallization temperature in both conventional and microwave heat-treated samples. However, pattern of spherulites growth under the microwave processing appeared to be quitely different from that under the conventional one due to its internal heating.

기름의 水面被膜에 따른 再曝氣係數의 變化

閔盛基,孫晋彦 동아대학교 환경문제연구소 1979 硏究報告 Vol.3 No.1

본 연구는 기름의 오염이 해양 및 하천에 미치는 영향을 검토함에 있어서 그 기초자료 내지 공업적 적용 방법을 알아보는데 있으며 대기에서 재폭기 계수의 변화를 측정, 고찰하는데 있다. 기름은 A-중유를 사용하였으며 수온은 5∼35℃까지 비교적 넓은 온도분포에 대해 실험적으로 검토하였다. 본 실험에 있어서는 유막이 존재할 때 재폭기 계수 k₂는 20∼40% 저하하고 온도계수 θ는 1,040으로 상승하여 DO평형농도는 최고 11%정도 증가함을 알았다. The purposes of this research are to find out the basic data for the examination of the effects of oil pollution upon the reaeration phenomena in seas and rivers, and the industrial application of the data, to measure and study the changing of reaeration rate of oil-covered pure water. Experiments were carried out with bunker-Atype petroleum as a covering material and at comparatively wide-ranging temperatures(5∼35℃). In the experiments, the changing of the reaeration coefficient k₂, and the temperature coefficient as well as that of the equilibrium concentration of dissolved oxygen in case of oil slicks were examined.

Drosophila melanogaster 韓國 自然集團에 있어서 P-M System에 依據한 Cytotype 分布 硏究

成耆昌,安成晥 성균관대학교 기초과학연구소 1988 論文集 Vol.39 No.1

Hybrid dysgenesis, aberrant phenomena, found in certain interstrain hybrids of Drosophila melanogaster, is caused by the interaction of chromosomal and cytoplasmic factors. 10 natural populations of D. melanogaster from Korea were investigated in order to determine the distribution of P factor and M cytotype, two components of P-M system. The results showed that: 1) The P factor activity for potential GD sterility is absent or present at only very low frequencies in these populations. 2) All locations show rather similar distributions, indicating weak M cytotype. The levels of activity of M cytotype were appeared to be variable among 10 populations. 3) Q cytotype, which cause immune to the P factor, was found at high frequencies in these populations. 4) The results seem to suggest that polymorphism of M and Q cytotype exists in Korean natural population.