• Journal of Dairy Science and Biotechnology
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• v.21 no.2
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• pp.114-119
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• 2003

Acidocin 4A produced by Lactobacillus acidophilus GP4A was purified to homogeneity by ammonium sulfate precipitation and sequential chromatographies containing Octyl sepharose CL-4B column, $C_{18}$ Sep-Pak Cartridge, $C_{18}$ RP HPLC and HPLC gel filtration. Tricine SDS-PACE resulted in a single band with estimated molecular mass of 4.1 kDa corresponding to the polypeptide weight marker. Electron microscopy of acidocin-treated indicator cells(L. delbrueckii subsp. lactis ATCC 4797) confirmed that acidocin 4A presented bacteriolytic effect, resulting in cell lysis. Curing trial using ethidium bromide (EtBr) was carried out to examine whether acidocin 4A determinant was encoded either by chromosome or on plasmid. The plasmid designated as pLA4A, being about 20 kb in size, was responsible for acidocin 4A production and immunity to host cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.400-400
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• 2010

우리는 기본 진공 $10^{-11}\;Torr$의 UHV surface magneto-optical Kerr effect (SMOKE) 시스템을 quarter-wave plate를 사용하였던 기존의 방식에서 PEM (photo elastic modulator)를 사용하는 방식으로 장비의 기능을 향상시켰다. 기존 quarter-wave plate를 사용하는 방식의 경우 Kerr signal을 구하기 위해 편광자와 검광자를 수직으로 두어 광량을 0으로 만들어야 한다. 그러나 금속의 경우 대부분 가시광선 영역에서 큰 반사율 때문에 측정되는 광량이 편광자와 검광자를 거치면서 넓은 각도 범위에서 최소값을 갖기 때문에 정확한 영점을 잡는 데 한계가 있다. 이러한 단점을 해결하기 위하여 우리는 PEM을 이용한 위상변조방식을 사용하였다. 위상변조 방식은 Kerr signal과 관계된 양을 PEM을 이용하여 50 kH ($1{\omega}$)와 100 kH ($2{\omega}$)의 진동 주파수에 공조시키고 이를 Lock-in-amplifier를 사용하여 탐지하기 때문에 좋은 sensitivity를 얻을 수 있을 뿐 아니라 Kerr ellipticity와 Kerr rotation을 동시에 측정할 수 있다. 자화에 필요한 전자석은 순철로 된 코어를 제작하여 챔버에 부착하였고 10 A에서 최대 7 kOe의 고자장을 얻을 수 있어 포화자화가 큰 물질에 대해서도 필요한 자성영역까지 측정이 가능하게 하였다. 또 저온 측정을 위해 SMOKE 샘플 홀더를 개조하여 액체 질소를 이용하여 100 K 근방의 영역에서 온도를 제어할 수 있도록 저온 장치를 구성하였다. 여기에서 샘플 근처에 위차한 e-beam heater가 장착된 고온 부분과 액체 질소 냉각, 온도감지를 위한 센서, cartridge heater가 장착된 저온 부분을 sapphire plate로 분리하여 저온용 cartridge heater의 파손을 최소화하였다. 이러한 SMOKE 시스템을 구성한 후에 우리는 Fe/Cr(001)시스템의 자성특성에 대해 연구하였다. Fe/Cr 시스템은 Fe/Cr/Fe의 exchange coupling이나 bulk Cr의 복잡한 자성 특성 때문에 주목을 받아왔다. 이 연구에서 우리는 저온 및 상온에서 Cr(001) 단결정 위에 증착된 Fe 박막의 자성 특성을 보고한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.293-296
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• 2008

Most of the guided weapons have been kept and transferred at the launching tube and fired in case of necessity in these day. Launching tube is a kind of case to protect the guided weapons from external environments and conducted as a guide when they are fired. When we attached the guided weapons to launching tube we usually has used explosive bolt. Explosive bolts have been used explosives when they had to be separated. But when they are separated there are some bad effects; a flame, fragments and pyro-shock. Because of these bad effects there are many restriction to use bolt as joining devices to precision guided weapons. To solve these problems, it has been invented ball type bolt. The present work was represented quantitively the margin of separation safty and separation mechanism in ball type bolt to analyse the dynamic separation test. Unlike explosive bolt, ball type bolt is separated without a flame, fragments and pyro-shock. And it also has a good mechanical properties as much as those of explosive bolt.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.841-846
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• 2019

The purpose of this work is to manufacture of high efficiency water-treatment filter that is equal to imported products or even higher in terms of quality and even develop the manufacturing process. The filtration efficiency of the developed filter was 93~99%, which was better or similar to that of domestic filter (82~97.5%) and Japanese filter (92.5~98%). The pressure loss(durability) along with the amount of contaminant particles was significantly smaller than that of domestic products, and showed $0.1kg_f/cm^2$ less than that of Japanese products. In addition, at the cost side of production, the developed cartridge filter can be produced with 50% of the current price compared to that of Japanese products. Therefore, it is possible to replace the imported Japanese products as well as domestic products.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.576-585
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• 2003

An improved method in place of a conventional vanillin spectroscopic method (CVSM) was developed for determination of catechin and its derivatives in extract and oil of grape seeds. For the CVSM, grape seed extracts had relatively high catechin content in the range of $17{\sim}43%$ (g/100g of extract), while grape seed oils had relatively smaller catechin content in the range of $30{\sim}40mg%$ (mg/100g of oil). For the improved vanillin spectroscopic method (IVSM) using a polyamide cartridge, catechin content of grape seed extracts was in the range of $4.0{\sim}7.5%$, while that of grape seed oils was below 5 ppm. Meanwhile, the quantities of catechin and its derivatives were determined by HPLC in the grape seed extracts and oils. Four major catechins [(+)-catechin, procyanidin B2, (-)-epicatechin, and epicatechin gallate] were detected from grape seed extracts, and the ranges of concentrations were as follows: (+)-catechin, $1.35{\sim}2.60%$; procyanidin $B_2$, $0.77{\sim}1.36%$; (-)-epicatechin, $2.35{\sim}4.59%$; (-)-epicatechin gallate, $0.06{\sim}0.30%$. In contrast, four catechins were barely detectable in the grape seed oils. The reproducibility of four major catechins in grape seed extracts, given as coefficient of variation, was below 5%, and the recovery close to above 95%. The achieved detection level of four catechins was $1{\sim}5\;ppm$. Additionally, the contents of catechin compositions in grape seed extract were also determined by HPLC in relation to different cultivars and producing areas. Thus, HPLC method and IVSM using polyamide cartridge can be used as alternative to CVSM for determination of catechin and its derivatives in extract and oil of grape seeds.

• Journal of Photoscience
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• v.3 no.1
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• pp.23-28
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• 1996

To investigate the structure and function of photosystem I, cartridge mutagenesis technique was used to inactivate the psaB gene of photosystem I. From the screen, many strains which have potential defects in photosystem I were generated. Biochemical analysis revealed that B2, one of the mutant, had a reduced amount of chlorophyll. Electron transfer activitx from photosystem II to photosystem I as oxygen uptake was the rate of 64 % of wild type. Also B2 showed a decreased photosystem I activity when measured by 77 K fluorescence emission spectrum. Particularly, immunodetection analysis showed that the B2 had reduced amount of PsaA/PsaB, but a normal range of PsaC and PsaD. Here we present a photoheterotrophic mutant for psaB gene as a unique model strain for future study of structural/functional relationship and biogenesis of photosystem I.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.3-10
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• 2014

The inferior alveolar nerve (IAN) block is the most frequently used mandibular injection technique for achieving local anesthesia for restorative and surgical procedures. However, The IAN block does not always result in successful anesthesia, especially pulpal anesthesia. Lidocaine is used as a "standard" local anesthetic for the inferior alveolar nerve. Articaine recently joined Korean market as a form of dental cartridge. It has an advantage of superior diffusion through bony tissue. A variety of trial was performed to improve the success rate of inferior alveolar nerve block. In this review, the recent update related with inferior alveolar nerve block anesthesia will be discussed on the anatomical consideration, anesthetic agent, technique, and complications.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1843-1847
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• 2010

An efficient method for the preparation of 1,4-disubstituted 1,2,3-triazole compounds is described using polymeric quaternary ammonium salts having azide or alkyne functionality to remove unreacted excess starting molecules (azide/alkyne). Copper metal could easily be removed by simple filtration with a short $Na_2SO_4$/silica cartridge, affording highly regioselective products in high yield and excellent purity without the need for work-up, extraction and chromatographic purification.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.269-278
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• 2000

The pressure-time profile of the explosion gases can controlled for the use of cartridge explosive with two techniques known as Decoupling and spacing of the charges. Decoupling consists of a space between the explosive column and wall of the blast hole. Four different decoupling index 1.4, 1.8, 2.34, 3.0 are selected in this field study. The level of ground vibrations with each decoupling index was measured and the empirical particle velocity equation from these data was obtained. The condition of new cracks at blast hole are also examined. As the decoupling index is increased, the level of the blast vibration is decreased. But the cracks in rock masses are efficiently formed to remove the broken rock. The vibration constant associated with test sites is given as $K=1564.5(D.L)^{-1.3233}$ in terms of D.I.(decoupling index).

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.85-90
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• 2001

This work presents experimental results of filter media test by using particles from $0.02\;to\;0.6{\mu}m$ in diameter and by applying different charging states. In order to investigate the electret filter performance, the collection efficiency and the pressure drop of filter were measured. The face velocities of test filters varied from 2.4 to 20.4 cm/s. Another experiment setup for the cartridge cabin air filter was used to get an collection efficiency in submicron region. After charging level of electret filter severely decreased, the change of collection efficiency was verified. Experimental results show that the reliability of electret filters can be poor in some conditions.