• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.10
• /
• pp.995-999
• /
• 2015

Inductive sensors are versatile and economical devices that are widely used to measure a wide variety of physical variables, such as displacement, force, and pressure. In this paper, we propose a simple inductive sensor consisting of a thin partial ring and a coil set. The self-inductance of the sensor was estimated using magnetic circuit analysis and validated through finite element analysis (FEA). The natural frequency of the ring was estimated using Castigliano's theorem and the method of equivalent mass. The estimation was validated through experiments and FEA. A prototype sensor with a signal processing circuit is built and applied to noninvasively sense the pressure inside a flexible tube. The obtained sensor outputs show quadratic behavior with respect to the pressure. When fitted to a quadratic equation, the least-square measurement error was less than 2%. The results confirm the feasibility of pressure sensing using the proposed inductive sensor.

• Journal of Korean Society of societal Security
• /
• v.1 no.4
• /
• pp.73-81
• /
• 2008

Electromagnetic induction surveys are one of the useful methods to detect the location and buried depth of underground utilities by measuring horizontal and vertical magnetic fields. It can effectively detects single buried utility with the accuracy of within 20 cm. However when another utility is buried near to target one, the accuracy of utility location considerably decreases due to the distortion of magnetic fields caused from adjacent utility. This study shows the ways to verify the location and buried depth of target utility when magnetic fields does not show symmetric distribution due to adjacent another utility. Using Bluetooth wireless communication tools, we developed the way to records measured magnetic fields to handheld PDA. We investigated the criteria for minimum distance of two adjacent utilities to separate the individual responses through field model test.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.2
• /
• pp.119-125
• /
• 2004

This paper is described the indirect induction heated boiler system and induction heated hot air producer using the voltage-fed series resonant high-frequency inverter which can operate in the frequency range from 20〔KHz〕 to 50〔KHz〕. A specially designed Induction heater, which is composed of laminated stainless assembly with many tiny holes and interconnected spot welding points between stainless plates, is inserted into the ceramic type vessel with external working coil. This working coil is connected to the resonant inverter. In the induction heater, it's primary heating section creates low-pressure saturated steam and secondary heating section generates heat distribution evaporating fluid from the turbulence fluid which is flowing through the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from the practical point of view.

• Korean Journal of Acupuncture
• /
• v.28 no.2
• /
• pp.23-36
• /
• 2011

목적 : 이 연구는 관절 및 심혈관계 질환 치료에 사용되는 송절(松節)(Pinus densiflora Gnarl)을 약침용 시료로 조제하여 본 약물의 항산화 효능을 규명하고자 하였으며 이를 다양한 시스템에서 검토하였다. 방법 : $FeCl_2$-ascorbic acid system에서 흰쥐 간조직의 지질과산화 반응을 관찰하였고, Fenton reaction system에서 자유기에 의한 plasmid DNA 분절을 유도하였다. 또한 deoxyribose assay를 통해 hydroxyl radical 소거능을 관찰하였고, NBT reduction assay로 superoxide radical 소거능을 검토하였다. 또한 human low-density lipoprotein(LDL)의 산화를 유도하기 위해 $CuSO_4$와 AAPH를 사용하였으며 relative electrophoretic mobility (REM) assay로 LDL 산화 억제 효능을 대조 항산화물질과 비교 검토하였다. 결과 : 송절 약침액은 자유기에 의한 간조직의 지질과산화(p < 0.01)및 DNA 분절을 현저하게 억제하였으며, hydroxyl radical, superoxide radical (p < 0.01), nitric oxide 및 peroxynitrite를 강하게 소거하였다. 또한 $CuSO_4$ ($IC_{50}=9.2{\pm}0.2\;{\mu}g/ml$)와 AAPH ($IC_{50}=34.8{\pm}5.1\;{\mu}g/ml$)에 의해 유도된 human LDL의 산화를 억제하였고, REM assay에서도 산화 억제 효능을 재확인할 수 있었다. 결론 : 송절 약침액은 활성산소종 및 활성질소종를 소거하였고, 지질과산화를 억제하였으며, 특히 human LDL의 산화적 손상을 방어하였다. 이에 본 약물은 자유기에 의한 심혈관의 산화적 손상을 효과적으로 보호할 것으로 판단된다.

• Journal of Aquaculture
• /
• v.6 no.4
• /
• pp.285-293
• /
• 1993

Gynogenetic diploid of olive flounder, Paralichthys olivaceus were induced by cold shock to fertilized eggs with red sea bream, Paragus major sperm that had been genetically inactivated with 4,800 ergs/$mm^2$ ultraviolet (UV) rays. Cold shock to the eggs at $2^{\circ}C$ for 45 minutes proved to be optimum condition to retain the second polar body. At this treatment, hatching rates of normal fry obtained were more than $33.8\%$. No different growth rates were observed up to 200 days after hatching between control and gynogenetic diploid offsprings. However, body weights of gynogenetic diploids were significantly heavier than that of control 300 days after hatching (p> 0.05). A proportion of female in gynogenetic diploid was significantly higher than that in the control (p< 0.01).

• Journal of the Korean Institute of Gas
• /
• v.4 no.3 s.11
• /
• pp.26-32
• /
• 2000

Because of the continuous growth of energy consumption, and also the tendency to site power lines and pipelines along the same routes, the close proximity of high voltage structures and metallic pipelines has become more and more frequent. Moreover, normal steady state and fault currents become higher as electric networks increase in size and power Therefore, there has been and still is a growing concern(safety of people marking contact with pipeline, risk of damage to the pipeline coating, the metal and equipment connected to pipeline, especially cathodic protection system) about possible hazards resulting from the influence of high voltage power system on metallic structures(gas pipeline, oil pipeline and water pipeline etc.). Therefore, we analyze the interference problems when the gas pipeline is buried with power cable in the same submarine tunnel. This paper present the results of the study about interference mechanism, AC corrosion limitation of safety voltage and analysis of induction voltage.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.4
• /
• pp.503-508
• /
• 2023

Tryptane derivatives are substances that treat acute migraines, and many studies have been conducted on analysis methods such as chromatography, electrochemistry, spectroscopy, and capillary electrophysiology. Recently, analytical chemists have become more interested in drug analysis and solving fundamental problems of biological importance. Therefore, in this study, the chemical properties of each derivative were investigated by calculating the total energy, band gap, electrostatic potential, and charge of Sumatriptan, Lizatriptan, Naratriptan, and Eletriptan using HyperChem8.0's semi-empirical PM3 method. As a result of this study, in the case of Sumatriptan, Naratriptan, and Eletriptan, chemical reactions are expected to proceed centering on oxygen and nitrogen atoms bonded to sulfur atoms. In addition, in the case of Rizatriptan without a sulfur atom, it was shown that the chemical reaction proceeds at the 17th and 19th nitrogens of the 5-membered heterocyclic compound.

• Membrane Journal
• /
• v.28 no.3
• /
• pp.214-219
• /
• 2018

In the present study, superflux nickel capillary supports for gas and vapor separation membranes were prepared by a combined process of NIPS and sintering. Nickel capillary precursors were prepared by NIPS process from PSf-Ni-DMAC-PEG400 dope solution and was sintered at various temperatures in $H_2$ atmosphere to reliably produce Ni capillary support. The optimized Ni capillary support has an outer and inner diameters of 722 and $550{\mu}m$, and its thickness was $94{\mu}m$. It has 3-dimensional pore channel network and its porosity and mean pore diameter was 26% and $4{\mu}m$, respectively. Also, its mechanical strength was tested in tensile mode: its fracture load was 2.84 kgf and the fracture elongation was 13%. Finally, its single gas permeance was measured: He, $N_2$, $O_2$, and $CO_2$ permeance was 432,327, 281,119, 264,259, and 193,143 GPU, respectively. The superflux behavior could be explained from viscous flow through the macropores having a diameter of $4{\mu}m$ and narrow thickness. It could be concluded that the superflux behavior of the Ni capillary support was from the 3-D pore channel network and the small thickness.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.1A
• /
• pp.69-78
• /
• 2008

In this study, in order to verify the reinforcement effects of the cracked concrete tubes and culverts, static load test was conducted. After the load carrying capacity of the original concrete tubes (nominal diameter 0.8 m, 1.0 m, 1.5 m) and box culverts (inner width 2.0 m. 2.5 m) was reduced by the cracking test, the cracked concrete specimens were strengthened by installing profile with steel stiffener and high strength mortar. And then, the maximum load tests were conducted the renewal concrete tubes and box culverts. According to the method application, the load carrying capacity increased 1.66~3.50 times than it of the original tubes before applying the method. In case of the original box culverts, the load carrying capacity increased 1.66~3.10 times than the case before installing profile and high strength mortar. Also non-linear analysis was carried out by using the commercial FEM program of ABAQUS 6.6. Solid (C3D8R) elements and concrete damage plasticity option was applied to the analysis. For reflecting confined reinforcing bars in the analysis, the composite material properties were used.

• Korean Journal of Microbiology
• /
• v.50 no.1
• /
• pp.27-32
• /
• 2014

Autophagy is one of the lysosomal degradation pathways to maintain cellular homeostasis. The damaged proteins or organelles are uptaken through extra- and intra-cellular stress, starvation and infected pathogens, subsequently, autophagosomes are fused with lysosomes to break down the molecules. Salmonella enterica serovar Typhimurium (S. Typhimurium), intracellular bacteria, cause acute gastroenteritis and food poisoning. Given that autophagy induced by S. Typhimurium plays an important role in the cells to control the infection, we identify whether the induction of autophagy with rapamycin, chemical inducer of autophagy, before infection regulates S. Typhimurium infection. After treatment of rapamycin or 3-methyladenine (3-MA), autophagy inhibitor, RAW264.7 cells were infected with S. Typhimurium. Pretretment of rapamycin decreased the growth rate of S. Typhimurium in the cells; otherwise, pretreatment of 3-MA increased the growth rate of S. Typhimurium. The expression of autophagy-related genes was significantly increased in the S. Typhimurium-infected cells pretreated with rapamycin. To examine whether induced autophagy by rapamycin control the infection with increase the production of reactive oxygen species (ROS) and nitric oxide (NO), antibacterial radical substrates were measured in infected cells followed by the treatment with either rapamycin or 3-MA. NO production increased in RAW264.7 cells; otherwise, ROS production remained unchanged during the infection. These findings suggest that inducing autophagy with rapamycin reveals antimicrobial activity as producing NO against S. Typhimurium infection in mouse macrophages.