• Membrane Journal
• /
• v.16 no.2
• /
• pp.115-122
• /
• 2006

In this study the membrane preparation and water vapor permeation of the hydrophilic polymer materials, polyaminosiloxane and polyhydroxylsiloxane, used as the coating materials for the preparation of asymmetric flat and hollow fiber membranes were investigated. And the water vapor permeation towards air permeation and their permselectivity were intensively studied for the resulting Resin A/Resin C (coupling agent) and Resin B/Resin C membranes. The water vapor permeability for 3 wt% Resin C introduced into Resin A (Resin A/Resin C) membrane was higher than for 1 and 5 wt% membranes and also water vapor permeability increased with increasing operating temperatures. In addition, at this content of 3 wt% Resin C, the absorption capability became maximum through dynamic equilibrium absorption experiment. Water vapor permeability, 43578 Barrer (1 Barrer = $10^{-10}cm^3(STP){\cdot}cm/cm^2{\cdot}s{\cdot}cmHg$) and 53000 Barrer, and the selectivity of $P(H_2O)P(Air)$, 101.3 and 102.6 were shown at 25 and $35^{\circ}C$, respectively.

• Membrane Journal
• /
• v.28 no.4
• /
• pp.221-232
• /
• 2018

The silica containing carbon ($C-SiO_2$) membranes were fabricated using poly(imide siloxane)(Si-PI) and polyvinylpyrrolidone (PVP) blended polymer. The characteristics of porous carbon structures prepared by the pyrolysis of polymer blends were related with the micro-phase separation behaviors of the two polymers. The glass transition temperatures ($T_g$) of the mixed polymer blends of Si-PI and PVP were observed with a single $T_g$ using differential scanning calorimetry. Furthermore, the nitrogen adsorption isotherms of the $C-SiO_2$ membranes were investigated to define the characteristics of porous carbon structures. The $C-SiO_2$ membranes derived from Si-PI/PVP showed the type IV isotherm and possessed the hysteresis loop, which was associated with the mesoporous carbon structures. For the molecular sieving probe, the $C-SiO_2$ membranes were prepared with the ratio of Si-PI/PVP and the pyrolysis conditions, such as the pyrolysis temperature and the isothermal times. Consequently, the $C-SiO_2$ membranes prepared by the pyrolysis of Si-PI/PVP at $550^{\circ}C$ with the isothermal time of 120 min showed the $O_2$ permeability of 820 Barrer ($1{\times}10^{-10}cm^3(STP)cm/cm^2{\cdot}s{\cdot}cmHg$) and $O_2/N_2$ selectivity of 14.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.3
• /
• pp.263-273
• /
• 2008

The precision of sensors' position is particularly important in the application of road extraction or digital map generation. In general, the various ranging solution systems such as GPS, Total Station, and Laser Ranger have been employed for the position of the sensor. Basically, the ranging solution system has problems that the signal may be blocked or degraded by various environmental circumstances and has low temporal resolution. To overcome those limitations a IMU/range integrated system could be introduced. In this paper, after pointing out the limitation of extended Kalman filter which has been used for workhorse in navigation and geodetic community, the two sampling based nonlinear filters which are sigma point Kalman filter using nonlinear transformation and carefully chosen sigma points and particle filter using the non-gaussian assumption are implemented and compared with extended Kalman filter in a simulation test. For the ranging solution system, the GPS and Total station was selected and the three levels of IMUs(IMU400C, HG1700, LN100) are chosen for the simulation. For all ranging solution system and IMUs the sampling based nonlinear filter yield improved position result and it is more noticeable that the superiority of nonlinear filter in low temporal resolution such as 5 sec. Therefore, it is recommended to apply non-linear filter to determine the sensor's position with low degree position sensors.

• Applied Biological Chemistry
• /
• v.13 no.1
• /
• pp.87-92
• /
• 1970

Sericin hydrolyzing enzyme, produced by the selected bacteria, S4-1-1, was studied and following properties were obtained. 1. The activity of this bacterial sericinase was not decreased for 30 days of storage at $5^{\circ}C$. But at $20^{\circ}C$, for 30 hrs. was the maximum period to keep the initial activity of this enzyme. 2. This bacterial enzyme gave only sericinase activity but never indicated fibroin hydrolyzing activity. 3. The chelating reagent of EDTA and Ag or Hg ions were classified as strung inhibitors but Cu and Cd ions were indicated as moderate inhibitors to this enzyme action. 4. This enzyme was not inhibited by the surface active agent, Peretex-N, but strongly activated by this agent at low concentration. In the other hand, by the application of this enzyme to the unwinding works on the mulberry cocoon, the following results were also obtained. 1. On the weight and length, nonbreaking Length, size, colour and unwinding ratio of have, the enzyme appling method was superior to generally used cooking method. 2. The tested results of strength and elongation, bouchon, haririness loops, neatness and evenness of have were also indicated spuerior properties.

• Korean Journal of Microbiology
• /
• v.40 no.4
• /
• pp.320-327
• /
• 2004

Three hundreds thirty two bacterial colonies which were able to degrade crude oil were isolated from soil sam­ples that were contaminated with oil in Daejeon area. Among them, one bacterial strain was selected for this study based on its higher oil degrading ability, and this selected bacterial strain was identified as Acinetobactor sp. B2 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Acinetobactor sp. B2 was able to utilize various carbohydrates but did not utilize trehalose and mannitol as a sole carbon source. Acinetobactor sp. B2 showed a weak resistance to antibiotics such as kanamycin, streptomycin, tetracycline and spectinomycin, but showed a high resistance up to mg/ml unit to heavy metals such as Ba, Li, Mn, AI, Cr and Pb. The optimal growth temperature of Acinetobactor sp. B2 was $30^{\circ}C.$ The lipase produced by Acinetobactor sp. B2 was purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Its molecular mass was about 60 kDa and condition for the optimal activity was observed at $40^{\circ}C$ and pH 10, respectively. The activation energy of lipase for the hydrolysis of p­nitrophenyl palmitate was 2.7 kcal/mol in the temperature range of 4 to $37^{\circ}C,$ and the enzyme was unstable at the temperature higher than $60^{\circ}C.$ The Michaelis constant $(K_m)\;and\;V_{max}$ for p-nitrophenyl palmitate were 21.8 uM and $270.3\;{\mu}M\;min^{-1}mg^{-1},$ respectively. This enzyme was strongly inhibited by 10 mM $Cd^{2+},\;Co^{2+},\;Fe^{2+},\;Hg^{2+},$ EDTA and 2-Mercaptoethalol.

• Journal of Life Science
• /
• v.19 no.11
• /
• pp.1568-1574
• /
• 2009

The purpose of this study was to investigate whether group III muscle afferents play an important role eliciting abnormal blood pressure response mediated during passive muscle stretch in prehypertensive individuals. Eleven middle-aged prehypertensive men (average BP 133/80 mmHg) and nine middle-aged normotensive men (average BP 119/74 mmHg) participated in this study. After 1 min rest baseline data collection, the subject's foot was flexed (dorsiflexion) by an automated cybex for one minute. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), heart rate, stroke volume, cardiac output, and total peripheral resistance were continuously measured on a beat-by-beat basis from a finger via a Finapres device for 1 minute. To evaluate the role of mechanoreflex, a component of exercise pressor reflex, SBP, DBP, and MAP responses over the course of time were examined. The results showed that the pressor response mediated by the muscle mechanoreflex was faster in prehypertensive individuals compared to the normotensive individuals. The substantial pressor response was observed within mean 20 sec of the onset of passive stretch in prehypertension, while mean 45 sec in normotension (p<0.05). It is concluded that excessive pressor response produced during exercise in prehypertension may be due to the dysfunction of the mechano-receptors.

• Korean Journal of Community Nutrition
• /
• v.8 no.5
• /
• pp.667-674
• /
• 2003

The paper examines the effect of physical exercise on blood lipid with young male students. Our analysis is based on the body measurement, food intake and blood lipid component for 70 male students of Kongju National University who either major in physical exercise (group A) or do not major in physical exercise (group B). The average weight of group A is 71.97 $\pm$ 10.79 kg while that of group B is 67.57 $\pm$ 8.66 kg. The former is significantly higher (p<0.05) than the latter. The SBP of group A (128.20 $\pm$ 11.40 mmHg) is significantly (p<0.001) higher than that of group B (136.27 $\pm$ 13.18 mmHg). In terms of the intake of total kcal, group A marks significantly higher than group B; group A goes with 2190.26 $\pm$ 581.96 kcal and group B goes with 2392.94 $\pm$ 769.03 kcal. The comparative analysis of the three nutrient intake shows that the intake proportions for group A are carbohydrate 55.08 $\pm$ 6.03%, protein 15.58 $\pm$ 2.75%, and lipid 29.34 $\pm$ 5.16% while the intake proportions for group B are carbohydrate 57.29 $\pm$ 8.09%, protein 15.62 $\pm$ 3.26%, and lipid 27.10 $\pm$ 6.90%. For group A, the vitamin B$_1$ intake amounts to 1.50 $\pm$ 0.5 mg which fulfills 100% of RDA, and the niacin intake amounts to 16.57 $\pm$ 5.54 mg N.E which is less than RDA. In contrast, both intakes for group B are more than the RDA. In the case with minerals except calcium, both group A and B mark more intake than RDA. Group A's calcium intake is 517.12 $\pm$ 200.63 mg and group B's is 409.56 mg. The total cholesterol intake for group A is 447.00 $\pm$ 245.08 mg which is significantly (p<0.05) higher than for group B with 352.35 $\pm$ 200.25 mg. The total cholesterol in the lipid of serum is 151.30 $\pm$ 12.92 mg/dl for group A and 182.30 mg/dl for group B, where the dominance of group B over group A is true at the level of significance 0.01. In the case with triglyceride, group A is 107.57 $\pm$ 31.60 mg/dl and group B is 108.07 $\pm$ 33.93 mg/dl so that the group difference is non-significant. The HDL-cholesterol for group A is 54.67 $\pm$ 6.49 mg/dl which is significantly higher (p<0.001) than for group B with 36.13 $\pm$ 4.64 mg/dl. We conclude that regular exercise may have an effect on blood lipid metabolism among young males.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.45 no.4
• /
• pp.508-513
• /
• 2018

Tidal volume by sevoflurane in small amounts is stable due to the increase in the breathing rate. But alveolus ventilation decreases due to sevoflurane as the degree of sedation increases; this ultimately causes $PaCO_2$ to rise. The occurrence of suppression of breath increases the risk of severe hypoxia and hypercapnia in deeply sedated patients with disabilities. Sevoflurane inhalation anesthesia has a number of risks and may have unexpected problems with hemodynamic changes depending on the underlying state of the body. This study was conducted to examine the stability of internal acid-base system caused by respiratory depression occurring when patients with disabilities are induced by sevoflurane. Anesthetic induction was carried out by placing a mask on top of the patient's face and through voluntary breathing with 4 vol% of sevoflurane, 4 L/min of nitrous oxide, and 4 L/min of oxygen. After the patient's loss of consciousness and muscle relaxation, IV line was inserted by an expert and intravenous blood gas was analyzed by extracting blood from vein. In a deeply sedated state, the average amount of pH of the entire patients was measured as $7.36{\pm}0.06$. The average amount of $PvCO_2$ of the entire patients was measured as $48.8{\pm}8.50mmHg$. The average amount of $HCO_3{^-}$ of the entire patients was measured as $27.2{\pm}3.0mmol/L$. In conclusion, in dental treatment of patients with disabilities, the internal acid base response to inhalation sedation using sevoflurane is relatively stable.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.15 no.2 s.38
• /
• pp.199-209
• /
• 1991

In this paper, the fabrics for Korean folk clothes(KFC) undergoes repeated laundering under given condition. After this cyclic laundering was applied, the mechanical properties of the specimen were measured using KES-F system in order to evaluated the end-use performance of fabrics for KFC. And also, the crease recovery of fabrics for KFC were measured by shirley crease recovery tester. 78 different kinds of commercial silk fabrics and polyester fabrics for KFC were used for this study. The experimental results were analysed statistically to relate the mechanical properties and the crease recovery of fabrics for KFC. Furthermore, these changes in dimensional stability, mechanical properties and handle of fabrics for KFC were discussed in comparison with those values for silk fabrics and polyester fabrics. The results obtained are as follows. 1. Regardless of materials, remarkable increase are observed in shrinkage of the fabrics for KFC about repeated laundering, but dull increase are observed in shrinkage after 10 cycles of the repeated laundering. On the other hand, slack extend are observed in dimensions after 20 cycles of the repeated laundering. The shrinkage of fabrics for KFC after 10 cycles of the lundering showed that the silk fabrics are $1.74{\pm}0.33\%$ (warp direction) and $1.35{\pm}0.23\%$ (weft direction) and the polyester fabrics are $1.45{\pm}0.22\%$ (warp direction) and $1.25{\pm}0.23\%$ (weft direction). 2. Except for tensile property, these changes in mechanical properties of fabrics for KFC by laundering have $\pm$ 16 range of bending, shearing, compression, surface, thickness & weight as compared with before laundering. Particularly, the LT and RT about $1\~3$ cycles of the repeated laundering showed remarkable decrease. And SMD, WC, T & W of fabrics for KFC by the laundering were more increased than one for original fabrics. But B, 2HB, G, 2HG, 2HGS were decreased more than one for original fabrics. 3. 'Stiffness', 'Anti-drape', 'Crispness' and 'Scroop' hand values decrease and'Fullness & softness', 'Flexibility & softness' hand values increase with repeated laundering. 4. Remarkable decrease are observed in crease recoveries about $1\~5$ cycles of the repeated lundering, but slack decrease are observed in crease recoveries after 5 cycles of repeated laundering. The crease recovery of fabrics for KFC have negative(-) correlation with LT, RT, G, RC and MMD, This fact implies that the smaller these values, the larger the crease recovery. The crease recovery of fabrics for KFC has a high degree of correlation with the mechanical properties such as shearing, compression, surface property. And also, the crease recovery are expected by measuring the mechanical properties such as G, 2HG, 2HGS, RC, WC, LC, MIU, MMD and SMD, according to the obtained regression equation.

• Applied Biological Chemistry
• /
• v.41 no.7
• /
• pp.489-495
• /
• 1998

The optimum culture condition of Scopulariopsis brevicaulis for the production of ${\alpha}$-galactosidase was as follows: Tryptone 1.5%, $NH_4NO_3$ 0.2%, Raffinose 2.5%, $KH_2PO_4$ 0.5%, yeast extract 0.5%, pH 7.0, $27^{\circ}C$. The optimum pH and temperature for the enzyme activity of ${\alpha}$-galactosidase producing Scopulariopsis brevicaulis were pH 7.0 and $27^{\circ}C$, respectively. The enzyme was relatively stable at $pH\;6.0{\sim}8.0$ and at temperature below $40^{\circ}C$. The activity of the enzyme was inhibited by $Ag^{2+},\;Hg^{2+},\;Cu^{2+}$, p-chloromercuribenzoic acid and Iodine. These results would indicate the presence of -SH groups in the catalytic site of the enzyme. Km value was 1.9 mM for $p-nitrophenyl-{\alpha}-D-galactopyranoside$ and Vmax value was $9.66{\times}10^2\;{\mu}M/min$. Sugar constituents of culture broth were identified by HPLC that the enzyme liberated sucrose, glucose and fructose from raffinose and raffinose was significantly decreased.