• The Korean Journal of Food And Nutrition
• /
• v.29 no.6
• /
• pp.829-834
• /
• 2016

Free radicals originate due to the radiolysis of cytoplasmic water with low "Linear Energy Transfer" (LET) radiations. Naringenin (Ng) is a natural antioxidative compound found in citrus fruits. This study revealed that Naringenin (Ng) reduced the radiation damage of critical organs by scavenging oxidative free radicals. In the study, Ng was orally administrated to rats daily for 7 consecutive days, prior to whole body exposure to gamma-rays. The scavenging efficacy was evaluated biochemically by measuring the concentration of cytotoxic byproducts and the activity of enzymes relevant to oxidative free radicals, after extracting the organs from the exposed rat. We observed increased levels of malondialdehyde (MDA) concentration, and decrease in the activities of superoxide dismutase (SOD) and catalase (CAT) in the exposed control group. However, pretreatment with Ng significantly reduced the MDA concentration, and increased the activities of SOD and CAT, as compared to the control group, due to the free radical scavenging by Ng. The results indicate that Ng administration prior to irradiation could protect critical organs from radiation damage.

• Journal of Sensor Science and Technology
• /
• v.16 no.5
• /
• pp.389-393
• /
• 2007

Soft ferromagnetic materials are very useful for many sensors using magnetic materials demanding high permeability, low coercivity and low hysteresis loss. Among them, FeCoSiBNi amorphous magnetic films show a good impedance change (about 5.01 %/Oe, at 10 MHz) by the exterinal magnetic field in this experiment. The magnetic films are produced by melt-spun method, one of the rapid solidification process. Ribbon shape wires were made from the films, and let them annealed in DC magnetic field to increase the maximum Giant Magneto Impedance ratio. Field annealing decreases the stress and changes the effective anisotropy. Thus, we can find that the impedance change (200.47 %) is improved and the fabricated magnetic wire has characteristics of good sensor element.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05c
• /
• pp.291-294
• /
• 2003

The circuit substrate was made from the Low Temperature Cofired Ceramics(LTCC) that a $\varepsilon_\gamma$ was 7.8. Accumulated Varactor and the low noise transistor which were a Surface Mount Device-type element on LTCC substrate. Let passive element composed R, L, C with strip-line of three dimension in the multilayer substrate circuit inside, and one structure accumulate band-pass filter, resonator, a bias line, a matching circuit, and made it. Used Screen-Print process, and made Strip-line resonator. A design produced and multilayer-type VCO(Voltage Controlled Oscillator), and recognized a characteristic with the Spectrum Analyzer which was measurement equipment. Measured multilayer structure VCO is oscillation frequency 1292[MHz], oscillation output -28.38[dBm], hamonics characteristic -45[dBc] in control voltage 1.5[V], A phase noise is -68.22[dBc/Hz] in 100 KHz offset frequency. The oscillation frequency variable characteristic showed 30[MHz/V] characteristic, and consumption electric current is approximately 10[mA].

• Journal of Welding and Joining
• /
• v.31 no.6
• /
• pp.37-43
• /
• 2013

This study targets to make clear the connection between MS (Martensite start) point and welding shrinkage. We approved that a Martensite-transformed weldment may not yield state under low MS point, but also admitted the limitation of numerical calculation by inherent strain approach or thermal strain approach. Therefore, new thermal strain formulae during cooling stages were made. As a thermal strain is obtained by integrating thermal extension coefficient, a constant of integration should be decided. In our suggested formulae, the origin was based on totally remained austenite, and added strain from volume changes in Martensite transformation was based on totally transformed ferrite. Through the suggested methodology, It is verified that an MS point under a critical temperature can let weld shrinkage relax and the critical value can be obtained. For supporting this process, 15 weld-consumables were made, were tested by fillet type and were measured. As a result, a positive correlation between MS point and level of weld-distortion was obtained, but it was rather weak.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.3
• /
• pp.207-214
• /
• 2005

After more than 100 years of development, rotating electric machines are a mature industrial product. Nevertheless, improvements are still possible for specific applications, and it is likely that the major evolution will be promoted by new materials and unconventional structures. Till now, plastic materials are an infrequent choice for the electric machines structural parts, but pioneering applications, such as aeronautical components, let some technological scouting: a low-weight/high-efficiency plastic axial flux motor for a solar flying platform is presented as an example of combined new-material/new-geometry development. The basic design aspects and the prototyping choices are presented and discussed together with the first experimental results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.163-168
• /
• 2007

A light railway operationis an effective means to solve a traffic problem of the city however, noise and vibration is pollution happened. This paper studied noise and vibration pollution of a light railway operation in order to let a decrease. The study range was only track condition and civil engineering structure condition. The way how we decrease noise and vibration in a protection vibration track, ballasted track, non-ballasted track, floating track trends was devoted is long rail laying, low vibration track lying. It was the most economic that the examination results track section a complement, and it was proved that a certain way.

• 한국연소학회:학술대회논문집
• /
• 1999.10a
• /
• pp.11-20
• /
• 1999

Acoustic pressure response and NO formation of hydrogen-air diffusion flames at various pressures are numerically studied by employing counterflow diffusion flame as a model flame let in turbulent flames in combustion chambers. The numerical results show that extinction strain rate increases linearly with pressure and then decreases, and increases again at high pressures. Thus, flames are classified into three pressure regimes. Such non-monotonic behavior is caused by the change in chemical kinetic behavior as pressure rises. Acoustic pressure response in each regime is investigated based on the Rayleigh criterion. At low pressures, pressure-rise causes the increase in flame temperature and chain branching/recombination reaction rates, resulting in increased heat release. Therefore, amplification in pressure oscillation is predicted. Similar phenomena are predicted at high pressures. At moderate pressures, weak amplification is predicted. Emission index of NO shows similar behaviors as to the peak-temperature variation with pressure.

• Journal of Korea Foundry Society
• /
• v.3 no.1
• /
• pp.22-27
• /
• 1983

In this paper, the cupola heat balance has been carried out by using programmable calculator with BASIC language. Computers tend to be used in almost every fields but for many people, computers are not handy yet because of its high equipment cost and its difficult language system. In view of this fact, a desk-top or a hand-held programmable calculator is the pertinent device in its calculation speed, accuracy, and easy programming language (BASIC), let alone its low cost. There have been some attempts to apply them to the foundry,${^{1),2)}}$ but they are little in number. This paper is the first attempt to apply the programmable calculator to the calculation of the cupola heat balance. After several applications in some practicalcases, the program has resulted in very satisfactory results such as saving of time and accuracy.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.38-41
• /
• 2002

Mammography is considered the single most important diagnostic tool in the early detection of breast cancer. Today's dedicated mammographic equipment, specially designed x-ray screen/film combinations, coupled with controlled film processing, produces excellent image quality and can detect very low contrast small lesions. In mammography, it is most important to produce consistent high-contrast, high-resolution images at the lowest radiation dose consistent with high image quality. Some of the major technical development milestones that have let to today's high quality in mammographic imaging are reviewed. Both the American College of Radiology Mammography Accreditation Program and the Mammography Quality Standards Act have significant impact on the improvement of the technical quality of mammographic images in the United States and worldwide. A most recent development in digital mammography has opened up avenues for improving diagnosis.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.1043-1048
• /
• 2009

This paper proposes the new operation control method that let heat source system stop and circulate only hot water at low load, and verified the introduction effect. At first, we constructed simulation model of heat source system and examined the proposing method by using simulation model. At last, we examined the introduction effect of proposing method with actual building. As a result, the primary energy consumption of heat source system was reduced by about 13%.