• Analytical Science and Technology
• /
• v.10 no.6
• /
• pp.403-407
• /
• 1997

Separation factor for $^6Li$ and $^7Li$ have been determined using ion exchange resin having 1,7,13-trioxa-4,10,16-triazacyclooctadecane($N_3O_3$) as an anchor group. The lighter isotope, $^6Li$ is concentrated in the solution phase, while the heavior isotope, $^7Li$ is enriched in the resin phase. By Ccolumnl chromatography[0.9cm(I.D)${\times}$20cm(height)] using 2.0M ammonium chloride solution as an eluent, single separation factor, ${\alpha}$, 1.009. i.e.$(^7Li/^6Li)_{resin}$/$(^7Li/^6Li)_{solution}$ was obtained by the Glueckauf theory from the elution curve and isotope ratios.

• Microbiology and Biotechnology Letters
• /
• v.13 no.2
• /
• pp.157-162
• /
• 1985

The cell cultures and crude extracts of Bacillus sphaericus 1593 K-5 and its mutant Spo-Dl216 were respectively bioassayed against Culex pipiens var. pollens mosquito larvae. The B. sphaeriucs 1593 K-5 showed toxic activity against the larvae. LC$_{50}$ values (cells/$m\ell$) was 2.6$\times$10$^2$. Also the LC$_{50}$ ($\mu\textrm{g}$ Protein/$m\ell$) of the crude extract was 10.26. However, B. sphaericus Spo-Dl216 didn't show toxic activity against the larvae. The soluble cytoplasmic toxin in broken B. sphaeriucs 1593k-5 cells was partially purified by gel permeation chromatography and ion exchange chromatography. Among the fractions of the gel permeation chromatography only a single fraction was found to be toxic. LC$_{50}$ values ($\mu\textrm{g}$ protein/$m\ell$) of the active fraction was 0.182. The active fraction of the gel permeation was subjected to ion exchange chromatography. Only a single fraction showed toxic activity and its LC$_{50}$ values ($\mu\textrm{g}$ protein/$m\ell$) was 0.02..02.

• Membrane Journal
• /
• v.21 no.1
• /
• pp.91-97
• /
• 2011

In this study, the anionic exchange membranes were prepared through the impregnation of polyethylenimine (PEI) into porous polyethylene (PE) separator and then crosslinking with isophrhaloyl dichloride (IPC). To characterize the resulting membranes, the contact angles, FT-IR, ion exchnage capacity and ion conductivity were measured. The amide group is produced the reaction between amines in PEI and -COCl in IPC. In case of ion exchange capacity, 1.96 meq./g dry membrane at the reaction time, 30 sec was decreased to 1.14 meq./g dry membrane at 600 sec reaction time. The ion conductivity, $9.15{\times}10^{-2}S/cm$ at 30 sec reaction time, was obtained.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.10
• /
• pp.3303-3310
• /
• 2012

Two single crystals of fully dehydrated partially $Li^+$-exchanged zeolite X were prepared by the exchange of Na-X, $Na_{92}Si_{100}Al_{92}O_{384}$ (Si/Al = 1.09), with $Li^+$ using aqueous 0.1 M $LiNO_3$ at 293 (crystal 1) and 333 K(crystal 2), followed by vacuum dehydration at 623 K and $1{\times}10^{-6}$ Torr for 2 days. Their structures were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group $Fd{\overline{3}}$ at 100(1) K. Their structures were refined using all intensities to the final error indices (using the 1281 and 883 reflections for which ($F_o$ > $4{\sigma}(F_o)$) $R_1/R_2$ = 0.075/0.244 and 0.074/0.223 for crystals 1 and 2, respectively. Their compositions are seen to be ${\mid}Li_{86}Na_6{\mid}[Si_{100}Al_{92}O_{384}]$-FAU and ${\mid}Li_{87}Na_5{\mid}[Si_{100}Al_{92}O_{384}]$-FAU, respectively. In crystal 1, 17 $Li^+$ ions per unit cell are at site I', 15 another site I', 30 at site II, and the remaining 16 at site III; 2 $Na^+$ ions are at site II and the remaining 4 at site III'. In crystal 2, 32 and 30 $Li^+$ ions per unit cell fill sites I' and II, respectively, and the remaining 25 at site III'; 2 and 3 $Na^+$ ions are found at sites II and III', respectively. The extent of $Li^+$ exchange increases slightly with increasing ion exchange temperature from 93% to 95%.

• Polymer(Korea)
• /
• v.26 no.1
• /
• pp.105-112
• /
• 2002

The low actuation voltage and quick bending response of IPMC(ion-exchange polymer metal composite) are considered attractive for the construction of various types of actuators. In this study, in order to develop a new type actuators by using the IPMC platinum electrode of IPMC are fabricated by using electroless impregnation-reduction method plating. As the platinum-plating times are increased, IPMC performance was improved in terms of bending displacement and force due to the enhanced surface conductivity. In addition, we investigated the basic actuation characteristics of resonance frequency and actuator length as well as the effect of water uptake and ion mobility. Using the classical laminate theory(CLT), a modeling methodology was developed to predict the deformation, bending moment, and residual stress distribution of anisotropic IPMC thin plates. In this modeling methodology, the internal stress evolved by the unsymmetric distribution of water inside IPMC was quantitatively calculated and subsequently the bending moment and the curvature were estimated for various geometry of IPMC actuator.

• Tuberculosis and Respiratory Diseases
• /
• v.42 no.6
• /
• pp.900-912
• /
• 1995

Background: Although graded exercise stress tests are widely used for the evaluation of cardiorespiratory performance, normal standards on respiratory gas exchange and ventilatory functions at maximal exercise in Koreans have not been well established. The purpose of this study is to provide reference values on these by sex and age, along with derivation of some of their prediction equations. Method: Symptom-limited maximal exercise test was carried out by Bruce protocol in 1,000 healthy adults consisting of 603 males and 397 females, aged 20~66 years. Among them VC, $FEV_1$ and MVV were also determined in 885 cases. All the subjects were members of a health center, excluding athletes. During the exercise, subjects were allowed to hold on to front hand rail of the treadmill for safety purpose. Results: The $VO_2\;max/m^2$, $VCO_2\;max/m^2$ and $V_E\;max/m^2$ were greater in males than in females and decreased with age. The RR max in men and women was similar but decreased slightly with age. The $V_T$ max was markedly greater in men but showed no significant changes with age in either gender. The mean of $V_T$ max/VC, $V_E$ max/MVV and BR revealed that there were considerable ventilatory reserves at maximal exercise even in older females. The regression equations of the cardinal parameters obtained using exercise time(ET, min), age(A, yr), height(Ht, cm), weight(W, kg), sex(S, 0=male; 1=female), VC(L), $FEV_1$(L) and $V_E$ max(L) as variables are as follows: $VO_2\;max/m^2$(L/min)=1.449+0.073 ET-0.007A+0.010W-0.006Ht-0.209S, $VCO_2\;max/m^2$(L/min)=1.672+0.063ET-0.008A+0.010W-0.005Ht-0.319S, VE max/$m^2$(L/min)=58.161+1.503ET-0.315A-9.871S or VE max/$m^2$(L/min)=47.873+6.548 $FEV_1$-5.715 S, and VT max(L)=1.497+0.223VC-0.493S. Conclusion: Respiratory gas exchange and ventilatory variables at maximal exercise were studied in 1,000 non-athletes by Bruce protocol. During exercise, the subjects were allowed to hold on to hand rail of the treadmill for safety purpose. We feel that our results would provide ideal target values for patients and healthy individuals to be achieved, since our study subjects were members of a health center whose physical fitness levels were presumably higher than ordinary population.

• Journal of Aquaculture
• /
• v.18 no.2
• /
• pp.115-121
• /
• 2005

This study was performed to investigate the formation and mass production of resting eggs by freshwater rotifer, Brachionus calyciflorus as influenced by different aeration supplements and exchange intervals of culture water in 15-L culture vessels and 500 L culture tanks. The maximum densities and mixis rates of the rotifers were not different between experimental group exposed to air or oxygen supplements. However, the fertilization rate and formation of resting eggs of the rotifers in the air-supplemented group were significantly higher than those in the oxygen supplemented group. In the experiment concerning exchange interval of culture water, the maximum density of the rotifers and formation of resting eggs in the batch culture were significantly higher than those in the semi-continuous culture with exchange of water every day. The formation of resting eggs per Chlorella dry weight was highest in the semi-continuous culture with exchange of water every day. The resting eggs of rotifers were produced at a density of $51.8{\sim}57.9{\times}10^6$ eggs in 500-L culture tanks. In this study, the batch culture with air is an effective method for mass production of resting eggs by the freshwater rotifer, B. calyciflorus, and the efficiency of mass production of resting eggs by this rotifer was similar to that of the seawater rotifers, B. plicatilis and B. rotundiformis.

• Journal of Korean Clinical Nursing Research
• /
• v.18 no.1
• /
• pp.99-110
• /
• 2012

Purpose: The purpose of this study was to examine the puncture incidence of surgical gloves in an operational setting. Methods: The 277 surgical gloves were used collecting at one general hospital located in Seoul from February 1, 2011 to April 3. The data were analyzed by $x^2$ test, Fisher's exact test, and multiple logistic regression. Results: In the dental and orthopedic department, the puncture incidence were significantly higher than others. The time of wearing gloves demonstrated significant difference: The group 181-240 minutes had a significantly higher than those with under 90, 91-180, or over 240 minutes. The influencing factors were as follows. Compared to that of the 2nd assistants, the puncture incidence rates of the surgeons were 9.91 times, scrub nurses were 8.39 times higher respectively. The participants in work experience under 1 year showed a 4.58 times higher than those with over 7 years. In addition, compared to the puncture incidence rate of neurosurgery department, the 17.41 times in cardio-thoracic surgery, 13.89 times in dental surgery, 4.93 times in gynecology, and 4.97 times in orthopedics higher respectively. Conclusion: There is a need for training operational room personnels to occasionally exchange the gloves even during the procedure and to use double surgical gloves.

• Analytical Science and Technology
• /
• v.14 no.4
• /
• pp.291-299
• /
• 2001

A method of separation and purification of Sm for quantitation of Sm isotopes from various fission products in PWR spent nuclear fuels has been studied. Simulated solution containing inactive metal ions(Cs, Ba, Gd, Eu, Sm and Nd) in place of radioactive fission products was prepared. Sm was separated with 0.5 M $HNO_3$/80% MeOH after washing with 1 M $HNO_3$/90% MeOH on AG $1{\times}8$, anion exchange resin. Sm was purified on cation exchange resin, AG $50W{\times}8$, pretreated with 0.2 M alpha-hydroxisobutyric acid(pH 4.5-4.6) to remove Ba causing isobaric effect Sm from PWR spent fuel. As a result of mass spectrometric measurement, eluted Sm portion did not include isobars form other elements such as Gd, Eu, Pm, Nd and BaO. The contents of Sm and its isotopes($^{147}Sm$, $^{148}Sm$, $^{149}Sm$, $^{150}Sm$, $^{151}Sm$, $^{152}Sm$ and $^{154}Sm$) in spent fuel were determined by isotope dilution mass spectrometric method spiking $^{154}Sm$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2000.10a
• /
• pp.140-145
• /
• 2000

The Exchange-cooperation of the Korean peninsula on the Internet contains the possibility that forms the basic of the South-North relationship to meet the Age of information. the Exchange-cooperation on the Internet will make a contributes to the frame of mutual cooperation in the two nations as solving the inconvenience, which might follow the direct contact between them, and cutting down on expenses. Focusing on the Internet, especially Software and Communication service in the Information and Communication sector. This paper presents the Establishment scheme of Cyber network for obtaining mutual cooperation on the Korean peninsula.