3,211 research outputs found
Numerical Analysis of Saturated Sand Under Dynamic Loads
In this study, the behavior of reclaimed soils including the effects of excess pore water pressure and the loss of strength under dynamic loads or earthquakes are investigated and simulated. The constitutive model based on the disturbed state concept (DSC) is introduced and DSC-DYN2D program is utilized in a numerical analysis. In the laboratory test, quasi-static and cyclic triaxial tests were carried out to determine parameters for the numerical analysis. Field tests were executed in Inchon International Airport with a 10 tons hydraulic hammer. In the field test, the data of dynamic loads and excess pore water pressure were measured using a 3-D geophone and a pressure transducer respectively, The data of field tests showed the accumulation of excess pore water pressure when rapid dynamic loads were applied. Especially, a back-prediction program based on DSC model is developed and verified its accuracy using various parameters from the cyclic triaxial test. As the results of numerical simulation, the predicted trends for excess pore water pressure compare well with the observed data. Based on the result of this research, it is found that the numerical analysis based on the DSC model is compatible to predict the softening behavior of saturated reclaimed soils under dynamic loads
Real-time detection of an airborne microorganism using inertial impaction and mini-fluorescent microscopy
To achieve successful real-time detection of airborne pathogenic microorganisms, the problem must be considered in terms of their physical size and biological characteristics. We developed an airborne microorganism detection chip to realize the detection of microorganisms, ensuring compactness, sensitivity, cost-efficiency, and portability, using three key components: an inertial impaction system, a cartridge-type impaction plate, and a mini-fluorescent microscope. The inertial impaction system was used to separate microorganisms in terms of their aerodynamic particle size, and was fabricated with three impaction stages. Numerical analysis was performed to design the system; the calculated cutoff diameter at each impaction stage was 2.02 (first stage), 0.88 (second stage), and 0.54 μm (third stage). The measured cutoff diameters were 2.24, 0.91, and 0.49 μm, respectively. A cartridge-type impaction plate was used, composed of molded polydimethylsiloxane (PDMS) and an actual impaction region made of a SYBR green I dye-stained agar plate. A mini-fluorescent microscope was used to distinguish microbes from non-biological particles. Images of the microorganisms deposited at the impaction zone were obtained via mini-fluorescent microscopy, and fluorescent intensities of the images were calculated using in-house image-processing software. The results showed that the developed system successfully identified aerosolized biological particles from non-biological particles in real time
The Impact of Overactive Bladder on Health-Related Quality of Life, Sexual Life and Psychological Health in Korea
Purpose We aimed to estimate the prevalence of overactive bladder (OAB) in Korea, to assess the variation in prevalence by sex and age, and to measure the impact of OAB on quality of life. Methods A population-based, cross-sectional telephone survey was conducted between April and June 2010 with a questionnaire regarding the prevalence of OAB, demographics, and the impact of OAB on quality of life. A geographically stratified random sample of men and women aged ≥30 years was selected. Results The overall prevalence of OAB was 22.9% (male, 19%; female, 26.8%). Of a total of 458 participants with OAB, 37.6% and 19.9% reported moderate or severe impact on their daily life and sexual life (5.6% and 3.5%, respectively, in participants without OAB). Anxiety and depression were reported by 22.7% and 39.3% of participants with OAB, respectively (9.7% and 22.8%, respectively, in participants without OAB). Only 19.7% of participants with OAB had consulted a doctor for their voiding symptoms, but 50.7% of respondents with OAB were willing to visit a hospital for the management of their OAB symptoms. Conclusions This study confirmed that OAB symptoms are highly prevalent in Korea, and many sufferers appear to have actively sought medical help. OAB has severe effects on daily and sexual life as well as psychological health
A Case Report of Reiter's Syndrome with Progressive Myelopathy
Reiter's syndrome belongs to the family of spondyloarthropathies that usually present with a triad of arthritis, urethritis, and uveitis. The diagnostic criteria include clinical, radiological, and genetic findings, and the response to treatment. Nervous system involvement in Reiter's syndrome is extremely rare. We report here on a 36-year-old man who initially presented with progressive cervical myelopathy and was diagnosed as Reiter's syndrome 2 years later. The myelopathy was stable after treatment with methotrexate and sulfasalazine. This case suggests that Reiter's syndrome can present as progressive myelopathy and should be considered in the differential diagnosis of treatable myelopathies
Fetal Pericallosal Lipoma: US and MR Findings
We report a case of fetal pericallosal lipoma occurring at the anterior interhemispheric fissure and associated with agenesis of the corpus callosum. During targeted prenatal ultrasonography at 26 weeks' gestation, the lesion was seen as a highly echogenic mass. MR imaging performed at 35 weeks' gestation and during the postnatal period revealed a pericallosal fatty mass and agenesis of the corpus callosum
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