• Title/Summary/Keyword: Resonance

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A Comparison Study of the Site Amplification Characteristics and Seismic Wave Energy Levels at the Sites near Four Electric Substations (4개 변전소시설 부지 인근관측소의 지반증폭 특성 및 파형에너지 수준 비교 연구)

  • Yoo, Seong-Hwa;Kim, Jun-Kyoung;Wee, Soung-Hoon
    • Journal of the Korean earth science society
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    • v.37 no.1
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    • pp.40-51
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    • 2016
  • The problem has been pointed out that the domestic design response spectrum does not reflect site amplification, particularly in the high frequency bands, including the fact that site specific response spectrum from the observed ground motions appears relatively higher than design response spectrum. Among various methods, this study applied H/V spectral ratio of ground motion for estimating site amplification. This method, originated from S waves and Rayleigh waves, recently has been extended to Coda waves and background noise for estimating site amplification. For limited time of periods, 4 electric substation sites had operated seismic stations at two separate locations (bedrock and borehole) within each substation site. H/V spectral ratio of S wave, Coda wave, and background noise, was applied to 36 accelerations of 3 macro earthquakes (Odaesan, Jeju and Gongju earthquakes), larger than magnitude 3.4. observed simultaneously at each bedrock location within 4 electric substation sites. Site amplifications at the bedrock location of 4 sites were compared among S wave, Coda wave energy, and background noise, and then compared to the previous results from the borehole location data. The site classification was also tried using resonancy frequency information at each site and location. The results suggested that all the electric substation sites showed similar site amplification patterns among S wave, Coda wave, and background noise. Each station showed its own characteristics of site amplification property in low, high and specific resonance frequency ranges. Comparison of this study to other results using different method can give us much more information about dynamic amplification of domestic sites characteristics and site classification.

A Case of Primary Pulmonary Artery Sarcoma (원발성 폐동맥 육종 1례)

  • Kim, Hee Joung;Seo, Suk Min;Kim, Sung Yong;Kim, Myung Sook;Kim, Seung Joon;Kim, Young Kyoon;Kim, Kwan Hyoung;Moon, Hwa Sik;Song, Jeong Sup;Park, Sung Hak
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.2
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    • pp.230-235
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    • 2003
  • A primary pulmonary artery sarcoma is a rare malignant tumor derived from the intimal layer of the pulmonary artery. Its clinical presentation can lead to a misdiagnosis of more common diseases such as thromboembolic disease. It is known to have a very poor prognosis. Therefore, the correct diagnosis of a primary pulmonary artery sarcoma is difficult and often delayed. We experienced a case of primary pulmonary artery sarcoma mimicking a pulmonary thromboembolism. The patient was admitted as a result of progressive dyspnea and coughing. The lung perfusion scan showed a large perfusion defect involving almost the entire right lung and suspicious small perfusion defects in the left upper lobe. Magnetic resonance imaging of the chest showed an enhancing nodule within the thrombus in the right pulmonary artery. The mass was removed completely by surgery, but the patient died as a result of shock.

Endobronchial Metastasis of Epithelioid Sarcoma

  • Kim, Seo-Yun;Lee, Ji-Yeon;Lee, Yeon-Joo;Park, Sung-Soo;Koo, Hyeon-Kyoung;Lee, Sang-Min;Yim, Jae-Joon;Yang, Seok-Chul;Yoo, Chul-Gyu;Han, Sung-Koo;Shim, Young-Soo;Kim, Young-Whan
    • Tuberculosis and Respiratory Diseases
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    • v.70 no.5
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    • pp.423-427
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    • 2011
  • Epithelioid sarcomas are rare soft tissue sarcomas with a high tumor grade and high local recurrence and metastasis rates. Although the lung is the most common site of metastasis, endobronchial metastasis hasn't been reported yet. We now report a case of epithelioid sarcoma with endobronchial metastasis. A 28-year-old man had recurrent pneumothorax and underwent wedge resection. He presented at our hospital with hemoptysis, dyspnea, and chest pain. Chest computed tomography revealed left pneumothorax, multiple lung nodules and endobronchial lesions at the right lower basal lobe. Bronchoscopy showed a hemorrhagic mass obstructing the bronchus of the right lower basal lobe. Magnetic resonance imaging revealed multiple nodular lesions in the left thigh muscles. The bronchoscopic biopsy of the endobronchial lesion and the muscle biopsy of the thigh showed the same feature epithelioid sarcoma. This is the first case report of an epithelioid sarcoma with endobronchial metastasis that was diagnosed by bronchoscopic biopsy.

Composition Changes in Cement Matrix of RC Column Exposed to Fire (화재에 노출된 RC기둥 시멘트 매트릭스의 구성성분 변화)

  • Kim, Jung-Joong;Youm, Kwang-Soo
    • Journal of the Korea Concrete Institute
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    • v.26 no.3
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    • pp.369-375
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    • 2014
  • This study examined the changes of microstructural compositions in cement matrix according to the depth from the surface of a reinforced concrete (RC) column exposed to fire. The RC column was exposed to a standard fire for 180 minutes. After the fire test, core samples passing through the column section were obtained. Using the core samples, the remaining fractions of calcium-silicate-hydrates (C-S-H) and calcium hydroxide in cement matrix at the surface, the depth of 40 mm and 80 mm and the center (175 mm) were examined using thermal gravimetric analysis (TGA) and X-ray diffraction analysis (XRDA). Using nuclear magnetic resonance (NMR) technique, the silicate polymerization of C-S-H in cement matrix was also evaluated. The experimental results indicated that the amount of C-S-H loss at the center of column experiencing the transferred fire temperature of $236^{\circ}C$ has been underestimated as the TGA results showed the highest C-S-H contents are located at the depth of 80 mm, where the transferred fire temperature is $419^{\circ}C$. Moreover, the destruction of silicate connections at the center was observed as similar as that at the depth of 40 mm, where the transferred fire temperature was $618^{\circ}C$. This might be attributed to the temperature changes during cooling time after the fire test was neglected. Due to the relatively low thermal conductivity of concrete, the high temperature, which can affect the change of microstructure in cements, will hold longer at the center of the column than other depth.

ESR-based Identification of Radiation-Induced Free Radicals in Gamma-Irradiated Basil and Clove Using Different Sample Pre-Treatments (감마선 조사된 바질과 정향의 전처리방법에 따른 ESR Spectra 판별 특성)

  • Kwak, Ji-Young;Ahn, Jae-Jun;Akram, Kashif;Kwon, Joong-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.10
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    • pp.1454-1459
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    • 2012
  • An improved detection of radiation-induced paramagnetic faults was developed to identify the irradiation status of basil and clove. The effectiveness of different sample pretreatments, including freeze-drying (FD), oven-drying (OD), alcoholic-extraction (AE), and water-washing and alcoholic-extraction (WAE), were examined. All non-irradiated samples showed a single central signal ($g_0$=2.006), whereas radicals representing two additional side peaks ($g_1$=2.023 and $g_2$=1.986) with a mutual distance of 6 mT were detected in the irradiated samples. AE and WAE produced the best results for irradiated clove in terms of intensities of radiation-specific ESR signals and their ratios to the central signal. However, FD provided the highest intensities of radiation-specific ESR signals for basil, whereas their ratios to the major signal were better in the cases of AE and WAE. Signal noise, particularly due to $Mn^{2+}$ signals, was observed, whereas it decreased in AE and WAE pretreatments. Based on our results, AE and WAE can improve the detection conditions for radiation-specific ESR signals in irradiated samples.

Comparative Study between MRI and pain, duration, physical examination in 20 patients with knee joint pain (20례 슬통환자의 통증, 이환기간, 물리적 검사법과 MRI소견과의 비교 고찰)

  • Yang, Myung-bok;Jang, Byung-sun;Lee, Dae-yong;Lee, Seung-hoon;Hwang, Byung-chun;Park, Jung-un;Guk, Ui-suk;Lee, Geon-mok
    • Journal of Acupuncture Research
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    • v.19 no.6
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    • pp.221-233
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    • 2002
  • Background and Purpose : MRI(Magnetic Resonance Imaging) has become one of the most sensitive diagnostic tool no evaluate problems of the knee, because it enables us to identify not only osseous tissue but also soft tissues including muscle, fascia, tendon, ligament, meniscus and fat around the knee joint. Objective : To compare between MRI reading and pain, duration, physical examination in patients with pain of knee joint. Methods : 20 patients with pain of knee joint included in this study. This study researched pain-degree, duration, physical examination with pain of knee joint. Using MRI(Horizon Lx 1.0T-GE), we obtained the results. Results : 1. In the distribution of sex; Female rate was 80.0% and male rate was 20.0%. In the distribution of age, above sixty group was the largest group by each 55.0%. 2. In the distribution of MRI reading; 'Meniscus horm tear' was 70.0%, 'Osteoarthritis' was 55.5%, 'ACL partial tear' was 15.0%, 'Bone bruise at tibia, femur' was 15.0%. 3. Correlation between duration of pain and MRI reading showed that acute and subacute stage related various MRI reading, that chronic stage related 'Osteoarthritis' and 'Meniscus horn tear' by each 69.2%, 92.3%. 4. Correlation between pain and MRI reading showed that severe pain(GVI) related 'ACL partial tear, PCL partial tear' by each 100%, that mild pain(GII) related 'Osteoarthritis, Meniscus horn tear' by each 70.0%, 80.0%. 5. Correlation between physical examination and MRI reading showed that Drawer test related ACL partial tear by each 60.0%, that McMurray test related 'Meniscus horn tear' by each 75.0%. 6. Correlation between effect of treatment and MRI reading showed that 'Osteoarthritis, Meniscus horn tear' related good effect, that ACL partial tear related poor effect. Conclusions : These results suggest that acute and sever pain relate 'ACL partial tear, PCL partial tear', that chronic and mild pain related 'Osteoarthritis, Meniscus horn tear'. So it is responsibility to use MRI as a sensitive diagnostic tool in the knee problems.

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Clinical Characteristics and Treatment Effects of Shoulder Pain Patients Admitted to a Korean Medicine Hospital Based on MRI Findings (한방병원에 입원한 견통 환자들의 MRI소견에 따른 임상적 특징, 한방치료 효과에 대한 비교고찰)

  • Lim, Su Jin;Jun, Jae Yun;Lee, Chong Whan;Kim, Hae Sol;Kim, Ho Sun;Bae, Young Hyun;Ahn, Ji Hoon
    • Journal of Acupuncture Research
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    • v.31 no.4
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    • pp.109-119
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    • 2014
  • Objectives : The aim of this study is to observe clinical characteristics and treatment outcomes of inpatients admitted to a Korean medicine hospital for shoulder pain based on magnetic resonance imaging(MRI) findings. Methods : 28 patients with MRI data were included. Data on MRI findings, duration of pain, and treatment effects were collected. To measure treatment outcomes, verbal numerical rating scale(VNRS), range of motion(ROM), and a clinical condition grading system were used. Results : 1. The patient population was 75.0 % female and 39.3 %(n=11) belonged to the 51~60-year-old age group. In the under 40 population, 1 or less MRI findings were found. 2. As for the type of disorder, 82.1 % of the patients were diagnosed with 'Supraspinatus lesion', 39.3 % with 'subacromial-subdeltoid(SA-SA) bursitis', and 28.6 % with 'Adhesive capsulitis' 3. Numerous correlations could be made between duration of pain and MRI findings. 'rotator cuff full thickness tear' was more prevalent in acute shoulder pain patients, and 'Adhesive capsulitis' in chronic patients. 4. VNRS and ROM at the time of discharge had significantly improved as compared to VNRS and ROM at the time of admission. 5. As for correlation between MRI findings and clinical condition grade, patients diagnosed with 'rotator cuff partial tear' reported to be in 'good' condition or better whereas those with 'rotator cuff full thickness tear' reported to be in 'fair' condition or worse. Conclusions : Patients admitted to a Korean Medicine hospital for shoulder pain had varying degrees of severity as shown on MRI. Almost all lesions responded well to Korean medicine treatment.

A Study on Dynamic Pile-Soil-Structure Interactions (말뚝-지반-구조물의 동섬 상호작용 연구)

  • Lee, In-Mo;Lee, Gwan-Ho;Kim, Yong-Jin
    • Geotechnical Engineering
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    • v.7 no.1
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    • pp.41-52
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    • 1991
  • A study of the effects of dynamic pile-soil-structure interactions on the response of super- structures, supported by group piles, are presented in this paper. The dynamic impedance functions of single pile generated by soil-pile interactions are obtained and compared among others using the methods proposed by Novak, Gazetas, and Kuhlemeyer, and using the equivalent cantilever method. Group pile effects are also considered by the following approaches : neglecting interaction effects : group efficiency ratio concept : static interaction approach . and dynamic interaction approach. The responses of a nuclear containment structure are obtained by using the elastic half-space analysis, based on the impedance functions mentioned above. Main conclusions drawn from this study are as follows : 1. The numerical results of the impedance functions calculated by each method were quite different : the Novak's was the smallest, and the Kuhlemeyer's the highest. Considering group effects, similar values in each approach were obtained for the stiffness : the difference was very big for the damping. 2. The top displacement of the structure was reduced by 20% or more by pile installations. However, the base shear force, the base moment, and the resonance frequency were increased by more than two times due to stiffening effect of the ground by pile installations. 3. Whether frequency dependant impedence functions or frequency independant functions were used, the responses of the structure were not so much affected by the choice of the impedance functions. 4. The reduction effect of the top displacement increased with the increase of the maximum ground acceleration.

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Physical and Chemical characteristics of Cokes Using Ash-Free Coal as binder (무회분 석탄(AFC)을 바인더로 이용한 코크스의 물리적 및 화학적 특성)

  • Kim, Gyeong Min;Kim, Jin Ho;Lisandy, Kevin Yohanes;Kim, Gyu Bo;Choi, Ho Kyung;Jeon, Chung Hwan
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.395-400
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    • 2017
  • Coke strength was increased by adding ash-free coal (AFC) binder. In this study, the effect of the AFC binder on the physical and chemical properties of coke was experimentally investigated to understand the molecular mechanism for the improved coke strength. For reduced $CO_2$ emission in steelmaking industry, torrefied biomass fuel mixed with coal binder is also considered. The interface between the base coal and AFC was thus examined using Scanning Electron Microscope (SEM). The coke strength was commonly measured by performing the indirect tensile test and Nuclear Magnetic Resonance (NMR) spectroscopy in $^1H$ and $^{13}C$ modes. For comprehensive mechanism study of the enhanced coke strength thus obtained, ordinary coal for thermal power plant use was carbonized with AFC for subsequent SEM examination. The NMR spectroscopy results of coke samples positively revealed that the tensile strength was proportional to the average number of aromatic rings.

Anaerobic Bacterial Degradation for the Effective Utilization of Biomass

  • Ohmiya, Kunio;Sakka, Kazuo;Kimura, Tetsuya
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.6
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    • pp.482-493
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    • 2005
  • Biomass is originally photosynthesized from inorgainic compounds such as $CO_2$, minerals, water and solar energy. Recent studies have shown that anaerobic bacteria have the ability to convert recalcitrant biomass such as cellullosic or chitinoic materials to useful compounds. The biomass containing agricultural waste, unutilized wood and other garbage is expected to utilize as feed, food and fuel by microbial degradation and other metabolic functions. In this study we isolated several anaerobic, cellulolytic and chitinolytic bacteria from rumen fluid, compost and soil to study their related enzymes and genes. The anaerobic and cellulolytic bacteria, Clostridium thermocellum, Clostridium stercorarium, and Clostridium josui, were isolated from compost and the chitinolytic Clostridium paraputrificum from beach soil and Ruminococcus albus was isolated from cow rumen. After isolation, novel cellulase and xylanase genes from these anaerobes were cloned and expressed in Escherichia coli. The properties of the cloned enzymes showed that some of them were the components of the enzyme (cellulase) complex, i.e., cellulosome, which is known to form complexes by binding cohesin domains on the cellulase integrating protein (Cip: or core protein) and dockerin domains on the enzymes. Several dockerin and cohesin polypeptides were independently produced by E. coli and their binding properties were specified with BIAcore by measuring surface plasmon resonance. Three pairs of cohesin-dockerin with differing binding specificities were selected. Two of their genes encoding their respective cohesin polypeptides were combined to one gene and expressed in E. coli as a chimeric core protein, on which two dockerin-dehydrogenase chimeras, the dockerin-formaldehyde dehydrogenase and the dockerin-NADH dehydrogenase are planning to bind for catalyzing $CO_2$ reduction to formic acid by feeding NADH. This reaction may represent a novel strategy for the reduction of the green house gases. Enzymes from the anaerobes were also expressed in tobacco and rice plants. The activity of a xylanase from C. stercorarium was detected in leaves, stems, and rice grain under the control of CaMV35S promoter. The digestibility of transgenic rice leaves in goat rumen was slightly accelerated. C. paraputrificum was found to solubilize shrimp shells and chitin to generate hydrogen gas. Hydrogen productivity (1.7 mol $H_2/mol$ glucos) of the organism was improved up to 1.8 times by additional expression of the own hydrogenase gene in C. paraputrficum using a modified vector of Clostridiu, perfringens. The hydrygen producing microflora from soil, garbage and dried pelletted garbage, known as refuse derived fuel(RDF), were also found to be effective in converting biomass waste to hydrogen gas.