• Title/Summary/Keyword: Pre-chamber

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Effect of Wear Training on Temperature Adaptability of the Obese Children (비만아동의 온도적응성에 대한 착의훈련 효과)

  • Jeong, Woon-Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.3 s.151
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    • pp.407-411
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    • 2006
  • This study was carried out to investigate the physiological responses of obese children after a short-term wear training and education. A ten-week program was conducted on thirteen obese elementary school children of six boys and seven girls in the 4th to the 6th grade. During the program, the children were instructed to measure daily ambient temperature and weight of their clothing. Physiological responses of the sedentary children in 100$\%$ cotton short sleeved t-shirt (0.13clo) and T/C short pants(0.09clo) were observed in the climatic chamber of 23.0$\pm$0.5$^{circ}C$ and 50$\pm$5$\%$RH before and after program. During the experiment, internal ear temperature ($T_{ear}$), seven site skin temperatures, systolic blood pressure, diastolic blood pressure, heart rate, and subjective responses of thermal comfort and thermal sensation were measured every 5minutes. Mean skin temperature($T_{sk}$) and mean arterial pressure(MAP) were calculated. Obtained data are statistically analyzed and main results are as follows. There was highly significant correlation between the ambient temperature and the total clothing weight. $T_{ear}$ and MAP were reduced in the post-program compared to the pre-program. The obese girls felt slightly warmer than the obese boys and the girls were likely to prefer lower ambient temperature in the post-program than the pre-program. It was concluded that the 10 week wear training is apt to be more applicable to the obese girls than the obese boys. However, a more comprehensive study including. diverse measurements of deep body temperature with a long-term training would be needed to clarify the improvement of temperature adaptability in the obese children.

Case study on design and construction for cross-connection tunnel using large steel pipe thrust method in soil twin shield tunnels underneath airport (공항하부 토사 병설 쉴드터널에서 대구경 강관추진에 의한 횡갱 설계/시공사례 연구)

  • Ahn, Chang-Yoon;Park, Duhee
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.5
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    • pp.325-337
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    • 2021
  • On the road and rail tunnels, the evacuation pathway and facilities such as smoke-control and fire suppression system are essential in tunnel fire. In the long twin tunnels, the cross-connection tunnel is usually designed to evacuate from the tunnel where the fire broke out to the other tunnel. In twin shield tunnels, the segment lining has to be demolished to construct the cross-connection tunnel. Considering the modern shield TBM is mostly the closed chamber type, the exposure of underground soil induced by removal of steel segment lining is the most danger construction step in the shield tunnel construction. This case study introduces the excavation method using the thrust of large steel pipe and reviews the measured data after the construction. The large steel pipe thrust method for the cross-connection tunnel can stabilize the excavated face with the two mechanisms. Firstly, the soil in front of excavated face is cylindrically pre-supported by the large steel pipe. Secondly, the excavated face is supported by the plugging effect caused by the soil pressed into the steel pipe. It was reviewed that the large steel pipe thrust method in the cross-connection tunnel is enough to secure the construct ability and stability in soil from the measurement results about the deformation and stress of steel pipe.

Determination of Undrained Shear Strength using Miniature Cone and T-bar Penetrometers for Kaolin Clay (소형콘과 T-bar 관입기를 이용한 카올린 점토의 비배수전단강도 산정에 관한 연구)

  • Sespene, Shemelyn;Choo, Yun Wook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.3
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    • pp.429-438
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    • 2018
  • Cone and T-bar penetrometers have been frequently used to estimate the undrained shear strength of clay. For small-size model tests, miniature penetrometers should be used but their correlation factors have not been well published. In this study, a testing setup was developed to derive empirical factors of the miniature cone and T-bar penetrometers. A 350mm-diameter chamber and kaolin clay were utilized to prepare soil specimens consolidated under four different pre-consolidation pressures controlling undrained shear strength. Two miniature cones with two diameters of 10-mm and 16-mm and a T-bar penetrometer with 10-mm diameter were used to investigate boundary effect, penetration rate effect, and diameter and shape effect. Unconsolidated-undrained triaxial tests were carried out with samples taken from the specimens to measure undrained shear strength. Finally, empirical factors for the penetrometers were constructed to correlate tip resistance to undrained shear strength.

The Properties of Beam Intensity Scanner(BInS) in IMRT with Phantom for Three Dimensional Dose Verification

  • Young W. Vahc;Park, Kwangyl;Byung Y. Yi;Park, Kyung R.;Lee, Jong Y.;Ohyun Kwon;Park, Kwangyl;Kim, Keun M.
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.64-64
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    • 2003
  • Objectives: Patient dose verification is clinically the most important parts in the treatment delivery of radiation therapy. The three dimensional(3D) reconstruction of dose distribution delivered to target volume helps to verify patient dose and determine the physical characteristics of beams used in intensity modulated radiation therapy(IMRT). We present Beam Intensity Scanner(BInS) system for the pre treatment dosimetric verification of two dimensional photon intensity. The BInS is a radiation detector with a custom made software for relative dose conversion of fluorescence signals from scintillator. Methods: This scintillator is fabricated by phosphor Gadolinium Oxysulphide and is used to produce fluorescence from the irradiation of 6MV photons on a Varian Clinac 21EX. The digitized fluoroscopic signals obtained by digital video camera will be processed by our custom made software to reproduce 3D relative dose distribution. For the intensity modulated beam(IMB), the BInS calculates absorbed dose in absolute beam fluence, which are used for the patient dose distribution. Results: Using BInS, we performed various measurements related to IMRT and found the followings: (1) The 3D dose profiles of the IMBs measured by the BInS demonstrate good agreement with radiographic film, pin type ionization chamber and Monte Carlo simulation. (2) The delivered beam intensity is altered by the mechanical and dosimetric properties of the collimating of dynamic and/or static MLC system. This is mostly due to leaf transmission, leaf penumbra, scattered photons from the round edges of leaves, and geometry of leaf. (3) The delivered dose depends on the operational detail of how to make multileaf opening. Conclusions: These phenomena result in a fluence distribution that can be substantially different from the initial and calculative intensity modulation and therefore, should be taken into account by the treatment planing for accurate dose calculations delivered to the target volume in IMRT.

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Change of Sperm Viability and Acrosome Integrity of Post-thawed Korean Jeju Black Bull Spermatozoa according to Glycerol Concentration (제주 흑우 동결 정액 제조에 있어 Glycerol의 농도에 따른 생존율 및 정자 첨체 양상의 변화)

  • Choi, Sun-Ho;Ko, Min-Hee;Kang, Tae-Young;Cho, Sang-Rae;Park, Yong-Sang;Oh, Shin-Ae
    • Journal of Embryo Transfer
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    • v.26 no.3
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    • pp.187-193
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    • 2011
  • This study was carried out to establish most suitable freezing condition, to evaluate the different glycerol concentration of freezing and thawing rates on motility, viability, membrane integrity and acrosome intecrity of frozen Korean Jeju Black Bull spermatozoa, Semen was collected from a Korean Jeju Black Bull using an artificial vagina and transported to the laboratory. The semen was extended gradually 1:5 then cooled slowly for 2 hrs to 4$^{\circ}C$. The semen was diluted 1:1 with cryoprotectant extenders (3%, 5% and 7% glycerol) and equilibrated for 2 hrs at cold chamber and packed to 0.5 ml straws. The semen straws were located above 3 cm of liquid nitrogen for 5 minutes, above 5 cm for 10 min and above 8 cm for 10 min. And then the frozen straw was plunged into LN$_2$. The presented straws were examined the viability and motility after thawed at 37$^{\circ}C$ water bath. The viability and membrane integrity immediately post-thawing were significantly higher in samples frozen in 7% glycerol than 3% and 5% glycerol (p<0.05). After CTC staining to assess acrosome integrity, F pattern was significantly increased, but B pattern was significantly decreased in 7% glycerol (p<0.05). Freezing distance of 5 cm from liquid nitrogen and pre-cooling for 10 min yield better survival and membrane integrity, but not significant difference. However, AR pattern according to CTC staining was significantly decreased in 3 cm for 5 min.

Preferential Decomposition of Nitrogen during Early Diagenesis of Sedimentary Organic Matter (퇴적물 내 유기물의 초기 속성 작용에 나타난 유기 질소의 선택적 분해)

  • Han, Myung-Woo;Lee, Khang-Hyun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.6 no.2
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    • pp.63-70
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    • 2001
  • Changes in concentrations of dissolved oxygen, ammonia, nitrate, pH, Fe and Mn were monitored from the laboratory incubation of an benthic chamber. The extent of sedimentary organic carbon and nitrogen decomposition was quantified by applying the concentration data to the chemical reaction equations of early diagenesis. The patterns of the concentration changes, observed during the 237 hr long incubation experiment, made it possible to divide the entire experiment period into four characteristic sub-periods (0-9 hr, 9-45 hr, 45-141hr, 141-237 hr). C/N ratio, estimated for each sub-period, was 6.63, 1.49, 0.81 and 0.02, respectively. This sequential decrease in C/N ratio suggests that during the incubation experiment dissolved nitrogen species diffuse more out of the sediment than dissolved carbon species. Greater diffusion of nitrogen indicates the preferential decomposition of organic nitrogen during early diagenesis of sedimentary organic matter. Comparison of the concentration data (sedimentary organic carbon and nitrogen, porewater organic carbon and ammonia)between the sediment pre and post incubation also indicates the preferential decomposition of nitrogen during early diagenesis of sedimentary organic matter.

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Sensing characteristics of Polypyrrole-based methanol sensors preparedbyin-situ vapor state polymerization

  • Linshu Jiang;Jun, Hee-Kwon;Hoh, Yong-Su;Lee, Duk-Dong;Huh, Jeung-Soo
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.137-137
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    • 2003
  • Conducting PPy/PVA composite and pure PPy gas sensors were prepared by in-situ vaporstate polymerization method in a vaporization chamber under N2 condition, by exposing the pre-coated electrode with PVA/FeC13 to distilled pyrrole monomer. The various electrical sensing behaviors of both types of sensors were systematically investigated by a flow measuring system including mass flow controller (MFC) and bubbling bottle. The FT-Raman spectroscopy of vapor state polymerized PPy was identical to that of chemically polymerized PPy, confirming the same chemical structure. Both types of sensors had positive sensitivity when exposed to methanol gas. The sensitivity varied linearly with gas concentration in the range of 50ppm to 1059ppm. The detection limit of PPy/PVA sensor was believed to be as low as 10ppm. The sensitivity of PPy/PVA composite sensor was higher than that of pure PPy sensor. Both the response time and recovery time of PPy/PVA composite sensors were longer than those of pure PPy sensors. The thickness of the sensing film affected the sensitivity this way that the sensor having thinner film had higher sensitivity, indicating that the resistance of polymer film involved in the sensing behavior was bulk resistance rather than surface resistance. The reproducibility of PPy/PVA composite sensor was excellent during eight on-off cycles by switching between N2 and 3000ppm methanol gas. The sensitivity of PPy/PVA composite sensor was only maintained for two weeks, while the sensitivity of pure PPy sensor was maintained over two months.

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A Study on the Measurement of the Beam Pattern of Array Antenna for VHF Radar using Active Beam Pattern Measuring Device and Drone (능동 빔패턴 측정장치 및 드론을 활용한 초단파레이다용 배열안테나의 빔패턴 측정에 대한 연구)

  • Kim, Ki-Jung;Lee, Sung-Je;Jang, Youn-Hui
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1031-1036
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    • 2019
  • This study describes the technique of the beam pattern measurement of array antenna for VHF band radar using drone and active beam pattern measuring device. There is no anechoic chamber for measuring the beam pattern of a large size antenna in the country. In this study, to test the antenna beam pattern characteristics of the developed VHF band radar, the antenna beam pattern characteristics were tested by Drone mounting an Active Beam Pattern Measuring Device. By comparing the results of the pre-simulation analysis with the measured results for the antenna, we could confirm that the beamwidth and side-lobe characteristics are satisfactory. Through the antenna beam pattern measurement technology using Drone and Active Beam Pattern Measuring Device, the beam pattern measurement technology of array antenna of low frequency band and large antenna for low band radar will be used.

Role of Dopamine upon Spontaneous Contraction of Isolated Rat Uterus in Diestrus State (Dopamine이 흰쥐 자궁의 자발적 수축에 미치는 영향)

  • Park, Hyoung-Jin;Sim, Yeo-Rim;Jo, Yang-Hyeok
    • The Korean Journal of Physiology
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    • v.17 no.2
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    • pp.103-107
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    • 1983
  • This experiment was undertaken to see whether dopamine has any effect on a uterine function and whether the uterus has a dopamine receptor. We used 14 female rats in the diestrus state which was identified by a vaginal smear. Under ether anesthesia, 3 pieces(1 cm length) from each side of the uterus were dissected out and mounted in 3 tissue chambers (4 cm diameter, 10 cm height) that contained Krebs-Ringer solution. The solution was continuously aerated with 95% $O_2$ containing 5% $CO_2$ and kept $37^{\circ}C$ consistantly during the whole experimental period. The spontaneous contractile activity of the isolated uterus was recorded using a force transducer. After a recovery period of 15 min in the chamber, the following experiments were carried out. In 7 rats, each piece of the uterus was received dopamine at concentrations of $10^{-4}$, $10^{-5}$ or $10^{-6}\;M$ for 10 min and then followed by domperidone at a concentration of $10^{-5}\;M$. In another 7 rats, each piece was received domperidone, a specific peripheral dopamine receptor antagonist, was administered at a concentration of $10^{-5}\;M$ for 5 min prior to dopamine at concentrations of $10^{-4}$, $10^{-5}$, or $10^{-6}\;M$. Dopamine inhibited the spontaneous uterine contraction dose-dependently (r=0.99, p<.01). The inhibited contractility by dopomine was significantly (P<.05) resumed by post-treatment of domperidone. Pre-treatment of domperidone also blocked significantly(p<.05) the inhibitory effect of dopamine. It is concluded from these results that dopamine has inhibitory role upon the spontaneous uterine contraction of the rat in the diestrus state and domperidone antagonized the inhibitory effect of dopamine. These results suggest strongly that dopamine may exert the inhibitory effect via the dopamine receptor in the rat uterus.

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A Study on the Provisions of the CIP·DDP·CIF in the Incoterms 2010 Coping with Their Problems and Alternatives (Incoterms 2010 CIP·DDP·CIF 규정상의 문제점과 대안에 관한 연구)

  • OH, Se-Chang;PARK, Sung-Ho
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.65
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    • pp.1-20
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    • 2015
  • International Commercial Terms, known as "Incoterms", are internationally accepted terms defining the responsibilities of exporters and importers in the arrangement of shipments and the transfer of liability involved at various stages of the transaction. The latest version of Incoterms rules were revised in 2010, so called Incoterms$^{(R)}$ 2010 which is the eighth set of pre-defined commercial terms published by the International Chamber of Commerce(ICC) in 1936. It has been already past 5 years since Incoterms$^{(R)}$ 2010 became effective January 1, 2011. At this point, we should examine the latest version of Incoterms whether the rules are not satisfied with the practical commerce because the customs and practices of commerce change constantly. The main purpose of this article is to seek a difference between the present commercial customs and practice and the rules of Incoterms$^{(R)}$ 2010. In addition, if there is any difference between them, an alternative resolution would be suggested. This article exercises the process of transition of the Incoterms rules, especially CIP, DDP, and CIF among 11 rules of Incoterms$^{(R)}$ 2010. Then this article provides some feasible alternatives to attempting to resolve some regulation problems of CIP, DDP, and CIF in the Incoterms$^{(R)}$ 2010. For examples, the practical meaning is different between "if customary or at the buyer's request" and "if agreed or customary" in CIF and CIP, especially a negotiable documentary being used. Furthermore, the interpretation of transfer of risks on the afloat goods in string sales in CIF term.

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