• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.3
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• pp.43-52
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• 1984

This paper is concerned with the strain characteristics of the time effect on the remoulded saturated day sampled from the downstream of the Yeongsan river, and the constitutive equation that can generally explain time-dependent behaviors of norma1ly consolidated clay. This paper examines whether or not the afore-said constitutive equation can be applied to the remoulded Mooan-clay. Throughout this study, the conclusions obtained are as follows. 1. Throughout the isotropic consolidation test for 7 days and the isotropic relaxation test, the existence of the static and dynamic yielding surfaces is confirmed respectively. 2. The characteristics of time effect of the deformation, namely, the existence of a unique stress-strain-time relation, is conformed from the experimental result on the Mooan-clay. 3. The prodictions of the stress path and the strain on the Cam-clay theory is not consistent with those observed during the experiments. 4. Constitutive equation(2-3-12) obtained by applying Cam-clay theory to Perzyna's elastic-viscoplasticity theory can explain the behavior of pore water pressure during isotropic stress relaxation, concerned with time dependency under undrained condition. The equation can also explain the results of the undrained triaxial compression test for the clay with different strain rate under the same or different consolidation history. 5. This constitutive equation has eight material parameters which can be determined from triaxial compression tests.

• Tuberculosis and Respiratory Diseases
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• v.79 no.1
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• pp.37-41
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• 2016

Iron supplements such as ferrous sulfate tablets are usually used to treat iron-deficiency anemia in some elderly patients with primary neurologic disorders or decreased gag reflexes due to stroke, senile dementia, or parkinsonism. While the aspiration of ferrous sulfate is rarely reported, it is a potentially life-threatening condition that can lead to airway necrosis and bronchial stenosis. A detailed history and high suspicion of aspiration are required to avoid delays in diagnosis and treatment. The diagnosis can be confirmed by bronchoscopic examination and a tissue biopsy. Early removal of the aspirated tablet prevents acute complications, such as bronchial necrosis, hemoptysis, and lobar consolidation. Tablet removal is also necessary to prevent late bronchial stenosis. We presented the first case in Korea of a ferrous sulfate tablet aspiration that induced severe endobronchial inflammation.

• Tuberculosis and Respiratory Diseases
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• v.57 no.6
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• pp.604-608
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• 2004

A 47-year-old-man was admitted to the emergency department with dyspnea, right pleuritic pain, and high fevers for 3 days. He had a nonproductive cough that exacerbated the chest pain. A clinical examination revealed distressed and slightly tachypneic patient, with blood pressure of 110/90 mmHg, temperature of $39^{\circ}C$, pulse of 90 beats/min, respiratory rate of 24 breaths/min. A chest examination showed significantly diminished breath sounds in the right lung with dullness to percussion. Laboratory investigation demonstrated leukocytosis and a raised C-reactive protein. The results of arterial blood gas analysis revealed moderate hypoxemia. A radiograph and a CT scan of the chest showed extensive consolidation with multifocal low densities, and pleural effusion in the right lung. A diagnostic thoracentesis revealed straw-colored fluid, which was found to be a neutrophil-predominant exudate. At 7 days after admission, the clinical symptoms had not improved and the temperature was still $39^{\circ}C$ despite the aggressive therapy of community-acquired pneumonia. After comprehensive history taking, we realized then that he accidentally aspirated kerosene while siphoning from fuel tank to put into the boiler 3 days ago. Bronchoscopy with bronchial washings could be successful in establishing the diagnosis of hydrocarbon pneumonitis by demonstration of a high lipid-laden macrophage index. Thereafter, the symptoms and radiographic opacities gradually improved, and he was discharged several days later.

• Journal of the Mineralogical Society of Korea
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• v.30 no.2
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• pp.71-81
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• 2017

Rock properties and the effects of chemicals that were used for conservation were studied for effective conservation treatment of Seated Buddha rock carving, which is composed of grayish white tuff, at Golguram Hermitage, Gyeongju. The rocks contain 3-5% montmorillonite, a swelling mineral and reacting with water, the d spacing of swelling minerals was increased (1.54-2.69%). On the one hand, the physical properties of the rock samples, such as surface hardness, water absorption rate, and porosity improved after the application of ethyl silicate-based stone strengthener. On the other, the interlayer of swelling minerals decreased and greater the of swelling mineral content, the greater is the extent of swelling (4.23-12.12%). When the ethyl silicate-based stone strengthener was applied after pretreatment with a swelling inhibitor, the physical properties were similar to those of the stone strengthener alone. There was no interlayer spacing change of swelling minerals due to swelling inhibition treatment; however, when the stone strengthener was applied after the swelling inhibitor, interlayer changes were similar to those when only the stone strengthener was treated (4.10-11.85%). Though the peak intensity of swelling minerals in X-ray diffraction pattern decreased, the effect of the swelling inhibitor was almost negligible. Therefore, it is not appropriate to use ethyl silicate-based stone strengthener for Golgulam rock containing swelling minerals and supplementing them with a swelling inhibition system is not effective. Because weathering rapidly progresses when swelling minerals contact moisture, for now, measures to prevent water contact, such as expansion of the canopy, are needed in the lower and side parts of the carving.

• Tuberculosis and Respiratory Diseases
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• v.70 no.4
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• pp.323-329
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• 2011

Background: Although patients with tuberculous-destroyed lung (TDL) account for a significant proportion of those with chronic airflow obstruction, it is difficult to distinguish patients with airway obstruction due to TDL from patients with pure chronic obstructive pulmonary disease (COPD) on initial presentation with dyspnea. We investigated clinical features differing between (i) patients with TDL and airway obstruction and (ii) those with COPD admitted to the intensive care unit (ICU) due to dyspnea. Methods: We reviewed the medical records of patients with TDL who had a forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) of <70% on a pulmonary function test (PFT; best value closest to admission) and patients with COPD without a history of pulmonary tuberculosis (TB) who were admitted to the ICU. Ultimately, 16 patients with TDL and 16 with COPD were compared, excluding patients with co-morbidities. Results: The mean ages of the patients with TDL and COPD were 63.7 and 71.2 years, respectively. Mean FVC% (50.4% vs. 71.9%; p<0.01) and mean FEV1% (39.1% vs. 58.4%; p<0.01) were significantly lower in the TDL group than in the COPD group. More frequent consolidation with TB (68.8% vs. 31.3%; p=0.03) and more tracheostomies (50.0% vs. 0.0%; p=0.02) were observed in the TDL than in the COPD group. Conclusion: Upon ICU admission, patients with TDL had TB pneumonia more frequently, more diminished PFT results, and more tracheostomies than patients with COPD.

• Geomechanics and Engineering
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• v.25 no.3
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• pp.207-219
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• 2021

Several additives are used to enhance the geotechnical properties (e.g., shear wave velocity, shear modulus) of soils to provide sustainable, economical and eco-friendly solutions in geotechnical and geo-environmental engineering. In this study, piezoelectric ring actuators are used to measure the shear wave velocity of unreinforced, fiber, cemented, and fiber reinforced cemented Toyoura sand. One dimensional oedometer tests are performed on medium dense specimens of Toyoura sand-cement-fiber-silica flour mixtures with different percentages of silica flour (0-42%), fiber and cement (e.g., 0-3%) additives. The experimental results indicate that behavior of the mixtures is significantly affected by the concentration of silica flour, fiber and cement additives. Results show that with the addition of 1-3% of PVA fibers, the shear wave velocity increases by only 1-3%. However, the addition of 1-4% of cement increases the shear wave velocity by 8-35%. 10.5-21% increase of silica flour reduces the shear wave velocity by 2-5% but adding 28-42% silica flour significantly reduces the shear wave velocity by 12-31%. In addition, the combined effect of cement and fibers was also found and with only 2% cement and 1% fiber, the shear wave velocity increase was found to be approximately 24% and with only 3% cement and 3% fibers this increased to 35%. The results from this study for the normalized shear modulus and normalized mean effective stress agree well with previous findings on pure Toyoura sand, Toyoura silty sand, fiber reinforced, fiber reinforced cemented Toyoura sand. Any variations are likely due to the difference in stress history (i.e., isotropic versus anisotropic consolidation) and the measurement method. In addition, these small discrepancies could be attributed to several other factors. The potential factors include the difference in specimen sizes, test devices, methods of analysis for the measurement of arrival time, the use of an appropriate Ko to convert the vertical stresses into mean effective stress, and sample preparation techniques. Lastly, it was investigated that there is a robust inverse relationship between α factor and 𝞫₀ exponent. It was found that less compressible soils exhibit higher 𝜶 factors and lower 𝞫₀ exponents.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1581-1588
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• 2021

Electronic cigarette (e-cigarette) or vaping product use-associated lung injury (EVALI) has emerged as a social issue as e-cigarette use is rapidly increasing worldwide and is related to many deaths in the United States. To our knowledge, this is the first case report of EVALI in South Korea of a 24-year-old man with acute respiratory symptoms and a history of e-cigarette use. Chest CT revealed diffuse bilateral ground-glass opacities with subpleural sparing, airspace consolidation, and centrilobular micronodules as typical patterns of EVALI with organizing pneumonia and diffuse alveolar damage. Infection was excluded with meticulous laboratory examinations, and the patients' illnesses were not attributed to other causes. EVALI was diagnosed by meeting the diagnostic criteria with consistent clinico-radiologic findings through a multidisciplinary approach. Radiologists should have good knowledge of EVALI radiologic findings and play a cardinal role in the proper diagnosis and management of EVALI.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.965-975
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• 1996

Background : Exogenous lipoid pneumonia is caused by inhalation or aspiration of animal, vegetable or mineral oil. Most cases are ascribed to aspiration of oil in laxatives or nose drops Petroleum, another pure hydrocarbon used as a base in various medications, is occasionally involved. Especially animal oil produces severe tissue inflammatory reaction, but most patients present with only abnormal chest X-ray and no specific clinical symptoms or signs. Method: Seven patients, 3 males and 4 females, with exogenous lipoid pneumonia, who was hospitalized or referred to pulmonary division at Samsung Medical Center from December 1994 10 July 1996, were included. They hadn a history of laking shark liver oil(so-called "squalene") for varying period of time. We reviewed clinical, radioloic and pathologic findings. Result: Patients look 7 to 30 capsules of "squalene" a day for at least one month to 5 years. Six cases had chronic disease such as diabetes, hypertension, or cerebrovascular accident. Respiratory symptoms of mild fever, cough and sputum were present in 3 cases and in 3 cases there was no clinical symptoms and signs but abnormal findings by chest X - ray. The major radiologic findings by simple chest X - ray and computed tomography consisted of consolidation, infiltration involving mainly right middle and both lower lobes, and ground-glass opacity. Five of six bronchoscopic examinations demonstrated both lipid droplets floating on the surface of bronchoalveolar lavage fluid and Lipid-laden macrophages in bronchoalveolar lavage fluid or lung tissue. Follow-up chest X -ray showed improvement in 4 cases but no marked interval change in 3 cases after removal of exposure to "squalene". Conclusion: Shark liver oil can induce lipoid pneumonia in adults. In case of high clinical suspicion, confirmation of "squalene" use by careful history taking is required and bronchoscopy is helpful in diagnosis.

• Tuberculosis and Respiratory Diseases
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• v.57 no.1
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• pp.19-24
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• 2004

Background : It is difficult to differentiate between tuberculous pneumonia and Community Acquired Pneumonia, so the diagnosis and treatment of tuberculous pneumonia can be delayed frequently. In this study, we attempted to retrospectively evaluate the clinical and radiologic characteristics of tuberculous pneumonia. Methods : We conducted a retrospective analysis of clinical characteristics of 58 patients diagnosed with tuberculous pneumonia from Nov. 1997 to May 2001 at Korea university kuro hospital. Result : The male to female ratio was 1:1 and the mean age at diagnosis was $54.5{\pm}18.6$ years. Fifty five patients were confirmed microbiologically and three patients pathologically. There were 20 patients(34.5%) who had diabetes mellitus(8cases), chronic obstructive pulmonary disease(3cases), malignancy(3cases), bronchiectasis(2cases), chronic renal failure(1cases) or long term history of corticosteroid treatment(3cases). Many patients had multilobar infiltration in chest X-ray, dominantly in the lower lobe. thirty two patients(55.2%) had infiltration in more than 2 lobes and 5 patients in more than 4 lobes. The significant correlation between the diabetes mellitus and the infiltrated Rt lower lobe(RLL) was found on the borders of confidence limit.(P=0.07<0.1). There was significant correlation between woman and infiltrated lobe(RML, RLL, LLL) excluding the both upper lobe(P=0.029). Conclusion : We must consider tuberculous pneumonia when lobar pneumonia with consolidation resistant to antibiotics, especially in the patients who have diabetes mellitus, chronic obstructive pulmonary disease, malignancy, bronchiectsis, chronic renal failure or long term history of corticosteroid treatment.

• The Korean Journal of Nuclear Medicine
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• v.39 no.4
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• pp.239-245
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• 2005

Purpose: Hypereosinophilic syndrome (HES) is an infiltrative disease of eosinophils affecting multiple organs including the iung. F-18 2-fluoro-2-deoxyglucose (F-18 FDG) may accumulate at sites of inflammation or injection, making interpretation of whole body PET scan difficult in patients with cancer. This study was to evaluate the PET findings of HES with lung involvement and to find out differential PET features between lung malignancy and HES with lung involvement. Material and Methods: F-18 FDG PET and low dose chest CT scan was performed for screening of lung cancer. light patients who showed ground-glass attenuation (GGA) and consolidation on chest CT scan with peripheral blood eosinophilia werr included in this study. The patients with history of parasite infection, allergy and collagen vascular disease were excluded. CT features and FDG PET findings were meticulously evaluated for the distribution of GGA and consolidation and nodules on CT scan and mean and maximal SUV of abnormalities depicted on F-18 FDG PET scan. In eight patients, follow-up chest CT scan and FDG PET scan were done one or two weeks after initial study. Results: F-18 FDG PET scan identified metabolically active lesions in seven out of eight patients. Maximal SUV was ranged from 2.8 to 10.6 and mean SUV was ranged from 2.2 to 7.2. Remaining one patient had maximal SUV of 1.3. On follow-up FDG PET scan taken on from one to four weeks later showed decreased degree of initially noted FDG uptakes or migration of previously noted abnormal FDG uptakes. Conclusions: Lung involvement in the HES might be identified as abnormal uptake foci on FDG PET scan mimicking lung cancer. Follow-up FDG PET and CT scan for the identification of migration or resolution of abnormalities and decrement of SUV would be of help for the differentiation between lung cancer and HES with lung involvement.