• Progress in Medical Physics
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• v.19 no.4
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• pp.269-275
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• 2008

Although MR imaging is generally applicable to depict knee joint deterioration it, is sometimes occurred to mis-read and mis-diagnose the common knee joint diseases. In this study, we employed magnetization transfer ratio (MTR) method to improve the diagnosis of the various knee joint diseases. Spin-echo (SE) T2-weighted images (TR/TE 3,400-3,500/90-100 ms) were obtained in seven cases of knee joint deterioration, FSE T2-weighted images (TR/TE 4,500-5,000/100-108 ms) were obtained in seven cases of knee joint deterioration, gradient-echo (GRE) T2-weighted images (TR/TE 9/4.56/$50^{\circ}$ flip angle, NEX 1) were obtained in 3 cases of knee joint deterioration, In six cases of knee joint deterioration, fat suppression was performed using a T2-weighted short T1/tau inverse recovery (STIR) sequence (TR/TE =2,894-3,215 ms/70 ms, NEX 3, ETL 9). Calculation of MTR for individual pixels was performed on registration of unsaturated and saturated images. After processing to make MTR images, the images were displayed in gray color. For improving diagnosis, three-dimensional isotropic volume images, the MR tristimulus color mapping and the MTR map was employed. MTR images showed diagnostic images quality to assess the patients' pathologies. The intensity difference between MTR images and conventional MRI was seen on the color bar. The profile graph on MTR imaging effect showed a quantitative measure of the relative decrease in signal intensity due to the MT pulse. To diagnose the pathologies of the knee joint, the profile graph data was shown on the image as a small cross. The present study indicated that MTR images in the knee joint were feasible. Investigation of physical change on MTR imaging enables to provide us more insight in the physical and technical basis of MTR imaging. MTR images could be useful for rapid assessment of diseases that we examine unambiguous contrast in MT images of knee disorder patients.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.5-16
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• 2012

In the case of using the soil materials created by cutting in-situ ground directly without adjusting particle size, it is recommendable to seek the compaction property or material constant required for filling design or density control through indoor test, and many studies on this subject have been carried out during that time. The researches conducted during that time, however, were focused on the mixed materials with different diameters that exist in a natural condition. There has been no study conducted using coal fly ash that is by-product of the thermal power plant that is actively considered as the building materials. Therefore, this study was aimed at implementing compaction test and examining the basic engineering property in order to explore the influence of crushing the particles through compacting the admixture of crushed stone and coal fly ash produced from thermal power plant on its engineering property, and then the impact of the admixture volume of each material on compaction property and material property by conducting the One-Dimensional Compression Test. As result of compaction test, the optimum moisture ratio of coal fly ash was shown to be approx. 23%. As result of compaction test in accordance with the mixed ratio of coal fly ash and crushed stone under the same compaction energy and moisture ratio, dry unit weight tended to drop when the mixed ratio of coal fly ash exceeded 30%, while it reached approx. $1.81gf/cm^3$ when the mixed ratio was 30%. As result of One-Dimensional Compression Test in accordance with the mixed ratio of crushed stone and coal fly ash, the change in void ratio by particle crushing was at the highest level in the case of coal fly ash 100%, while the lowest level in the case of crushed stone 100%. In the case of mixed materials of crushed stone and coal fly ash, compression index was at the lowest level in case of coal fly ash 30%, and therefore this ratio of mixed material was judged to be the most stable from an engineering aspect.

• Fibers and Polymers
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• v.7 no.4
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• pp.450-456
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• 2006

The objectives of this study were to investigate physiological and psychological responses to the rustling sound of Korean traditional silk fabrics and to figure out objective measurements such as sound parameters and mechanical properties determining the human responses. Five different traditional silk fabrics were selected by cluster analysis and their sound characteristics were observed in terms of FFT spectra and some calculated sound parameters including level pressure of total sound (LPT), Zwicker's psychoacoustic parameters - loudness(Z), sharpness(Z), roughness(Z), and fluctuation strength(Z), and sound color factors such as ${\Delta}L\;and\;{\Delta}f$. As physiological signals, the ratio of low frequency to high frequency (LF/HF) from the power spectrum of heart rate variability, pulse volume (PV), heart rate (HR), and skin conductance level (SCL) evoked by the fabric sounds were measured from thirty participants. Also, seven aspects of psychological state including softness, loudness, sharpness, roughness, clearness, highness, and pleasantness were evaluated when each sound was presented. The traditional silk fabric sounds were likely to be felt as soft and pleasant rather than clear and high, which seemed to evoke less change of both LF/HF and SCL indicating a negative sensation than other fabrics previously reported. As fluctuation strength(Z) were higher and bending rigidity (B) values lower, the fabrics tended to be perceived as sounding softer, which resulted in increase of PV changes. The higher LPT was concerned with higher rating for subjective loudness so that HR was more increased. Also, compression linearity (LC) affected subjective pleasantness positively, which caused less changes of HR. Therefore, we concluded that such objective measurements as LPT, fluctuation strength(Z), bending rigidity (B), and compression linearity (LC) were significant factors affecting physiological and psychological responses to the sounds of Korean traditional silk fabrics.

• 보존과학연구
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• s.22
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• pp.5-25
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• 2001

The germicidal and insecticidal properties of volatile components extracted from star anise(Illicium verum Hooker filius) and clove (Eugenia caryophyllata THUNBERG)were evaluated against five microorganisms and three insects for the purpose of developing biocidal active substances from medicinal plants. The volatile components of star anise and clove showed strong antimicrobial effect against Aspergillus niger, Penicillium funiculosum, Mucor hiemalis, Trichoderma viride, and Aureobasidium pullulans. The extracts of each medicine also showed insecticidal effects against Sitophilusoryzae L., Lyctus linearis GOZE, and Reticulitermes spertus kyushuensis Morimoto. Fumigant toxicities to adult insects were determined. In the case of fumiganttoxicity, the extract of star anise showed 100% mortality against R. spertus, S.oryzae, and L. linearis at rates of $2.5\mu\ell$, $50\mu\ell$, $250\mu\ell$/filter paper, respectively but showed no killing effects by clove. The volatile components of star anise and clove were investigated by means of GC/MS. The main constitute, anethole among 20components from star anise and eugenol among 9 components from clove were identified. The mixture of star anise and clove as the volume ratio of 2 : 1 showed higher properties for antimicrobial and insecticidal effect than each volatile component. A. niger was inhibited by the mixture(125ml/$m^3$) for up to 10 days of exposure. Also, from the result of observing state change of organic materials by volatile extracts of star anise and clove, volatile extracts effects have no effect on natural organic materials of organic cultural properties and can be used as biological control agent. As research contents as above, the insecticidal and germicidal agents from star anise and clove and the mixture of them were more efficient and high level to prevent biological damage for conservation of organic cultural properties. So they may be used in new development of biologicalinsecticidal and germicidal agents for conservation of cultural properties.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.275-280
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• 1995

The effect of supplemented high protein diet intake on renal urea regulation in swamp buffalo was carried out in the present experiment Five swamp buffalo heifers weighing between 208-284 kg were used for this study. The animals were fed with a supplementary high protein diet and renal function and kinetic parameters for urea excretion were measured. This was compared to a control period where the same animals had been fed only with paragrass and water hyacinth. For 2 months the same animals were fed a mixed of paragrass, water hyacinth plus 2 kgs of a high protein supplement (protein 18.2% DM basis) per head per day. In comparison to the control period, there were no differences in the rate of urine flow, glomerular filtration rate (GFR), effective renal plasma flow (ERPF), plasma urea concentration and filtered urea. In animals supplemented with high protein intake mean values of urea clearance, excretion rate and the urea urine/plasma concentration ratio markedly increased (p < 0.05) while renal urea reabsorption significantly decreased from 40% to 26% of the quantity filtered. In this same study group urea space distribution and urea pool size increased which coincided with an increase in plasma volume (p < 0.05). Plasma protein decreased while plasma osmolarity increased (p < 0.05). Both urea turnover rate and biological half-life of $^{14}C$-urea were not affected by a supplementary high protein intake. The results suggest that animals supplemented with high protein diets are in a state of dynamic equilibrium of urea which is well balanced between urea excreted into the urine and the amount synthesized. The limitation for renal tubular urea reabsorption would be a change in extra-renal factors with an elevation of the total pool size of nitrogenous substance.

• Clinical and Experimental Pediatrics
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• v.61 no.11
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• pp.362-365
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• 2018

Purpose: This study aimed to analyze changes in QRS duration and cardiothoracic ratio (CTR) following pulmonary valve replacement (PVR) in patients with tetralogy of Fallot (TOF). Methods: Children and adolescents who had previously undergone total repair for TOF (n=67; median age, 16 years) who required elective PVR for pulmonary regurgitation and/or right ventricular out tract obstruction were included in this study. The QRS duration and CTR were measured pre- and postoperatively and postoperative changes were evaluated. Results: Following PVR, the CTR significantly decreased (pre-PVR $57.2%{\pm}6.2%$, post-PVR $53.8%{\pm}5.5%$, P=0.002). The postoperative QRS duration showed a tendency to decrease (pre-PVR $162.7{\pm}26.4$ msec, post-PVR $156.4{\pm}24.4$ msec, P=0.124). QRS duration was greater than 180 msec in 6 patients prior to PVR. Of these, 5 patients showed a decrease in QRS duration following PVR; QRS duration was less than 180 msec in 2 patients, and QRS duration remained greater than 180 msec in 3 patients, including 2 patients with diffuse postoperative right ventricular outflow tract hypokinesis. Six patients had coexisting arrhythmias before PVR; 2 patients, atrial tachycardia; 3 patients, premature ventricular contraction; and 1 patient, premature atrial contraction. None of the patients presented with arrhythmia following PVR. Conclusion: The CTR and QRS duration reduced following PVR. However, QRS duration may not decrease below 180 msec after PVR, particularly in patients with right ventricular outflow tract hypokinesis. The CTR and ECG may provide additional clinical information on changes in right ventricular volume and/or pressure in these patients.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.219-238
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• 1999

In the present study, laboratory tests including the seepage-induced consolidation test, suction test, and desiccation shrinkage test are performed to investigate characteristics of the desiccation shrinkage in reclaimed hydraulic fills. Soil samples for laboratory tests are obtained from three sites (districts of Haenam, Kogeum and Koheung in Chunnam area). Desiccation shrinkage settlement caused by three dimensional volume change is numerically evaluated using finite difference technique based on the governing equation proposed by Abu-Hejleh & Znidarcic. Also characteristics of the desiccation shrinkage analyzed from the test results are used as input data for numerical evaluations. Further predicted total settlements including the self-weight consolidation settlement are compared with values measured at the site of Haenam district. Finally, effects of parameters related to the desiccation shrinkage on settlements are examined.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.3
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• pp.188-195
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• 2014

This paper was evaluated the rheology properties according to each step of paste, mortar and HPFRCC as a part of the basic study to development of sprayed high performance fiber reinforced cementitious composites(HPFRCC) for protection and blast resistant. Rheology test results in step of paste, in case of GGBFs and FA, it showed that the plastic viscosity and yield stress reduced gradually according to the increase of mixing rate, and in case of SF, the plastic viscosity and yield stress increased radically starting from the mixing rate of 10%. Rheology test results in step of mortar, type of aggregates, it showed that particle shape and grading of aggregate is influence on plastic viscosity and yield stress, and change of volume ratio is influence on plastic viscosity than yield stress. Fluidity and rheology test results in step of HPFRCC, if after a fiber mixed, it showed that viscosity agent is more effective to improve the fluidity and fiber dispersion than superplasticizer.

• Journal of Energy Engineering
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• v.11 no.2
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• pp.130-135
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• 2002

Bypass air conditioning systems are divided into three types; outdoor air bypass, mixed air bypass and return air bypass system. Among bypass air conditioning systems, a return air bypass system is more effective than other two systems because it doesn't induce unconditioned outdoor air into conditioned room. The numerical study on the bypass air conditioning system shows this system can maintain indoor RH(Relative Humidity) less than a conventional CAV (Constant Air Volume) air conditioning system by adjusting face and bypass dampers at part load. A simulator was built to compare results of a numerical experiment and those of a simulator experiment. The results of the simulator experiment was nearly same as those of the numerical experiment; when a design sensible load (the ratio of sensible load to total sensible load) was 70 percent (at this time, RSHF=0.7), indoor relative humidity (in case of both numerical experiments and simulator experiments) was maintained below 60% specified by ASHRAE STANDARD 62-1999. The bypass air conditioning system is expected to be applied to many buildings where the Percentage of latent loads or air change tate is high.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.181-181
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• 2016

Hydrogenated microcrystalline silicon (${\mu}c-Si:H$) films have attracted much attention as materials of the bottom-cells in Si thin film tandem photovoltaics due to their low bandgap and excellent stability against light soaking. However, in PECVD, the source gas $SiH_4$ must be highly diluted by $H_2$, which eventually results in low deposition rate. Moreover, it is known that high-rate ${\mu}c-Si:H$ growth is usually accompanied by a large number of dangling-bond (DB) defects in the resulting films, which act as recombination centers for photoexcited carriers, leading to a deterioration in the device performance. During film deposition, Si nanoparticles generated in $SiH_4$ discharges can be incorporated into films, and such incorporation may have effects on film properties depending on the size, structure, and volume fraction of nanoparticles incorporated into films. Here we report experimental results on the effects of nonoparticles incorporation at the different substrate temperature studied using a multi-hollow discharge plasma CVD method in which such incorporation can be significantly suppressed in upstream region by setting the gas flow velocity high enough to drive nanoparticles toward the downstream region. All experiments were performed with the multi-hollow discharge plasma CVD reactor at RT, 100, and $250^{\circ}C$, respectively. The gas flow rate ratio of $SiH_4$ to $H_2$ was 0.997. The total gas pressure P was kept at 2 Torr. The discharge frequency and power were 60 MHz, 180 W, respectively. Crystallinity Xc of resulting films was evaluated using Raman spectra. The defect densities of the films were measured with electron spin resonance (ESR). The defect density of fims deposited in the downstream region (with nonoparticles) is higher defect density than that in the upstream region (without nanoparticles) at low substrate temperature of RT and $100^{\circ}C$. This result indicates that nanoparticle incorporation can change considerably their film properties depending on the substrate temperature.