• Geomechanics and Engineering
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• 제34권5호
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• pp.577-595
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• 2023

A dynamic triaxial discrete element numerical model of lightweight soil was established using the discrete element method to study the microscopic mechanism of expanded polystyrene (EPS) particles in the soil under cyclic loading. The microscopic parameters of the discrete element model of the lightweight soil were calibrated depending on the dynamic triaxial test hysteresis curves. Based on the calibration results, the effects of the EPS particles volume ratio and amplitude on the contact force, displacement field, and velocity field of the lightweight soil under different accumulated strains were studied. The results showed that the hysteresis curves of lightweight soil exhibit nonlinearity, hysteresis, and strain accumulation. The strain accumulated in remolded soil is mainly tensile strain, and that in lightweight soil is mainly compressive strain. As the volume ratio of EPS particles increased, the contact force first increased and then decreased, and the displacement and velocity of the particles increased accordingly. With an increase in amplitude, the dynamic stress of the particle system increased, and the accumulation rate of the dynamic strain of the samples also increased. At 5% compressive strain, the contact force of the particles changed significantly and the number of particles deflected in the direction of velocity also increased considerably. These results indicated that the cemented structure of the lightweight soil began to fail at a compressive strain of 5%. Thus, a compressive strain of 5% is more reasonable than the dynamic strength failure standard of lightweight soil.

• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.33-38
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• 2011

Prompt and accurate diagnosis of malaria is the key to prevent disease morbidity and mortality. This study was carried out to evaluate diagnostic performance of 3 commercial rapid detection tests (RDTs), i.e., Malaria Antigen Pf/Pan$^{TM}$, Malaria Ag-Pf$^{TM}$, and Malaria Ag-Pv$^{TM}$ tests, in comparison with the microscopic and PCR methods. A total of 460 blood samples microscopically positive for Plasmodium falciparum (211 samples), P. vivax (218), mixed with P. falciparum and P. vivax (30), or P. ovale (1), and 124 samples of healthy subjects or patients with other fever-related infections, were collected. The sensitivities of Malaria Ag-Pf$^{TM}$ and Malaria Antigen Pf/Pan$^{TM}$ compared with the microscopic method for P. falciparum or P. vivax detection were 97.6% and 99.0%, or 98.6% and 99.0%, respectively. The specificities of Malaria Ag-Pf$^{TM}$, Malaria Ag-Pv$^{TM}$, and Malaria Antigen Pf/Pan$^{TM}$ were 93.3%,98.8%, and 94.4%, respectively. The sensitivities of Malaria Ag-Pf$^{TM}$, Malaria Antigen Pf/Pan$^{TM}$, and microscopic method, when PCR was used as a reference method for P. falciparum or P. vivax detection were 91.8%, 100%, and 96.7%, or 91.9%,92.6%, and 97.3%, respectively. The specificities of Malaria Ag-Pf$^{TM}$, Malaria Ag-Pv$^{TM}$, Malaria Antigen Pf/Pan$^{TM}$, and microscopic method were 66.2%, 92.7%, 73.9%, and 78.2%, respectively. Results indicated that the diagnostic performances of all the commercial RDTs are satisfactory for application to malaria diagnosis.

• Applied Microscopy
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• 제36권3호
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• pp.209-216
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• 2006

투과전자현미경을 이용한 3차원적 구조분석의 신뢰도를 향상시키기 위해서는 고니오미터와 사용되는 시료 홀더에 대한 정확도와 정밀도의 측정 및 보정이 필요하다. 본 연구에서는 상업용 투과전자현미경 홀더 중의 하나인 rotation holder에 대한 작동원리를 기술하고 회전각의 정확도를 측정하였다. 투과전자현미경 내부에서 회전된 이미지의 분석을 통한 홀더의 회전각의 측정오차는 ${\pm}0.42^{\circ}$이었다. 회전각의 정확도를 비교하기 위해 투과전자 현미경 외부에서 시료 홀더에 부착된 반사경에 레이저 빔을 반사시켜 측정한 결과, 회전각의 측정오차는 ${\pm}0.6^{\circ}$이었다. 추가적으로 시료컵과 회전벨트 사이의 불안정한 맞물림에 의해 야기된 비정상적인 시료의 회전경로에 대해서도 점검하였다.

• 대한수의학회지
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• 제31권2호
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• pp.209-215
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• 1991

Serological survey were conducted on the leptospiral antibody in domestic animals which were fed in the three rural village occurred human leptospirosis. Names of three villages are Shinnam-li, Shinjeop-li and Jinai-li which are located in near the northeastern part of Yeoju town in Kyunggi province. Total 66 serum samples were collected from the domestic animals in which 12 dairy cows, 10 Korean native cattle, 12 pigs and 32 dogs were included. Leptospiral antibody were detected with 4 different serovars of leptospira living antigens, such as Leptospira icterohaemorrhagiae, L. pomona, L. canicola and L. tarassovi by microscopic agglutination test for each serum sample. The results are obtained as follow. 1. All 66 sera collected from the domestic animals at three villages showed negative reaction with 4 different serovars of leptospiral antigen. 2. Only one serum sample taken from a dairy cow in Shinjeop-li showed a weak positive reaction with Leptospira tarassovi. It is suggest that this positive case is not infected with L. tarassovi, but with vaccination. 3. It is indicated that all domestic animals which wen, fed in the villages occured human leptospirosis were not infected with above 4 different serovars of leptospira at least.

• Composites Research
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• 제17권1호
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• pp.38-46
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• 2004

본 논문의 목적은 탄소섬유 건직물의 토우 구조의 미소 거동과 변형 중의 평면 하중과의 관계를 규명하는 것이다. 평면 하중은 변형 중에 토우들을 재배치하며, 결국에는 잠김 현상을 유발하게 된다. 본 논문에서는 토우 간격, 주름각등의 미소 변형 변수들을 관찰하기 위해 일방향 편향 인장실험과 이축 인장실험을 겪은 시편들을 전단각에 따라 분류하여 현미경을 이용하여 변형 경향을 관찰하였다. 전단각에 따른 변형된 토우 구조의 변화를 간단한 설계 변수 모델을 이용하여 근사하였다.

• 대한한의학방제학회지
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• 제15권2호
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• pp.119-126
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• 2007

Objectives: This study presents observation of microorganism such as total aerobic bacteria, total fungus, E. coli, Pseudonomas aerugjnosa, Staphylococcus aureus, and Salmonella typhimurium in herbal decoction manufactured by Korean medical clinic. Methods: We examined to observe microorganism using the requirements for the experimental methods recommended by FDA. For the identification, we observed microscopic methods and carried out polymerase chain reaction (PCR) and DNA purification. The purified DNA samples were analyzed by DNA sequencer. As compared with NCBI database. the results were identified by sequences similarity. Results and conclusion: 26 (55%) of 46 decoctions observed positive for microbial test. 12 (46 %) of 26 positive decoctions exceed requirement of microbial limit test. These microbial colony identified genus of Bacillus using microscopic and DNA sequencing methods.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권1호
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• pp.45-54
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• 1997

The purpose of this investigation was to determine the biomechanical property of calvarial defects reconstructed using toothash, plaster and tooth-plaster mixture. Full-thickness bony defects were made on the rat calvaria with size of $10mm{\times}10mm$. Group 1 was filled with toothash only, group 2 : toothash-plaster mixture, and group 3 : plaster only. The defects were allowed to heal for 12 and 20 weeks before killing the animals. Light microscopic examinations vas taken after 12 week after operation. The hardness was evaluated for test of mechanical property. The following results were obtained : 1. In light microscopic examination 12 week after operation, there were no inflammatory and foreign body reaction. Implanted particles were resorbed gradually or united directly with newly formed bone. 2. In hardness test, the hardness of newly formed bone was lower than that of normal bone and there was significant difference(P<0.01). The site of new bone formation has enough hardness to resist the mechanical stress. These results suggest that toothash and plaster are biocompatible and osteoconductive material.

• 대한미생물학회지
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• 제21권2호
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• pp.205-210
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• 1986

Serological investigations for the leptospirosis on hospitalized patients in Choonchun Sungsim Hospital during the periods from August to November 1985 and 841 inhabitants of Kangwondo area including Choonchun, Choonsung, Inje, Chulwon, Hwachun, Gosung, Taibaik, Samchuk and Yangju area were carried out. 1. Among 58 hospitalized patients who were suspected as leptospirosis, 10 patients were detected to have antibody against Leptospira. All of positive sera had the highest antibody titer against serogroup Icterohemorrhagiae and most positive sera were also reactive to serogroup Australis and Canicola. Antibody titer of positive sera detected by microscopic agglutination(MA) test were ranging from 1 : 40 to 1 : 2,560. Antibody titer detected by ELISA method were higher than those detected by MAT(ELISA 1 : 400$\sim$1 : 25,600) and IgM titer of positive sera were generally higher than IgG titer. 2, Of 841 inhabitants in 8 area of Kangwondo, 17 persons (2,02%) possessing antibody against Leptospira were detected by ELISA method, IgG titer in positive sera were generally higher than IgM titer. Persons possessing antibody to Leptospira were distributed in both sex and in various age group, and no significant regional and occupational fluctuations were obserbed.

• Journal of Chest Surgery
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• 제22권3호
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• pp.373-383
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• 1989

Glutaraldehyde is known as an ideal preservatives for pericardial heterograft, and many laboratories used this chemicals for preparing tissue valves, pericardial patches and MVOP [monocusp ventricular outflow patch] so we tried to find out the appropriate concentration and ingredients of the Glutaraldehyde for the preparing bovine pericardium. We selected 50 calves, aged about 2 years, and procured their pericardia. These were divided 6 groups such as fresh group, treated with only antibiotics, treated with Glutaraldehyde 0,5%, 0.625 %, 0.75 %, and 0.875 %, and our experiments included microbial culture test, tensile strength measurement and microscopic examination. On microbial culture, there were no growth on 1 week and 4 weeks after preparation with all kind of Glutaraldehyde, but on 4 weeks after only antibiotics treatment [Penicillin, Streptomycin, Kanamycin, Amphotericin -B] E.coli and candida albicans were observed. On tensile strength test, 0.625 % and 0.75 % Glutaraldehyde were revealed as the best preservatives for bovine pericardium and compared to other commercial products they kept more desirable tensile strength. On light and electron microscopic examinations, Glutaraldehyde treated pericardia had much regular and compact collagen fibers and preserved more normal structures, but there were no difference between the different concentration of the Glutaraldehyde. We concluded that 0.625% and 0.75 % Glutaraldehyde were the best concentration for preservation of bovine pericardium in our experiment.

• 대한교통학회지
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• 제13권1호
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• pp.185-203
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• 1995

The purpose of this paper is to develop a microscopic traffic simulation model which is able to both analyze and the evaluate signlaized urban network and to verify its usefulness in comparison with the other model which has alfeady been released. This simulation model adopts the General Motor's 5th model for car-following and introduces an unique lanechanging rule using acceptable gap. It analyzes single and dual-ring signal phases and generates detector information . So it could be applied to dynamic route guidance systems as wel as real time signal control systems. The results derived from Netsim and the observed data from the real network have been used to test the validit of the proposed model. The result of the test has shown that there are no significant differences between the NETSIM model and the proposed model in estimating travel speed and stopped delay. In optimum offset estimatin , it has shown the same results with NETSIM. the measure of effectiveness , however, derived from this model is slightly better than that of the real network situation. This may be due to the fact that the proposed model does not take into account side frictions from interferences and obstacles.