• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.3-13
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• 2001

It has been known that nonlinear characteristics of sorption affect the transport behavior of water soluble pollutants in soils. However detailed experimental studies have not been performed to verify the effect of non-linearity of adsorption isotherm on transport of chemicals in porous media. In this research, the distortion of breakthrough curves of a cationic surfactant (cetylpyridinium chloride, CPC) in a engineered stainless steel column packed with glass beads were investigated. Glass beads with about 110 $\mu\textrm{m}$diameter coated with a thin n-decane film were used as the media providing the sorption surface for CPC. The CPC adsorption isotherm on the surface of n-decane from aqueous solution was a typical Langmuir type. The breakthrough curve of CPC using step Input showed a late breakthrough on the front side and early breakthrough on the back side accordance to the shape of the isotherm. The retardation factor of CPC was found to be a strong function of the input concentration, which also a manifestation of the non-linearity of the isotherm. The retardation factors for the CPC with step input agreed with those of pulse input that the maximum concentrations are controlled to be the same as the step input concentrations. This results support the validity of the unproven field practices of using hydrogeotracers with non-linear adsorption isotherms to determine the hydrogeological parameters, e.g., NAPL saturation, air-water or NAPL-water interfacial areas.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.668-673
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• 2010

This study was to evaluate the effects of tramadol and medetomidine administration on minimum alveolar concentration (MAC) of isoflurane in dogs. MAC of isoflurane was determined in four occasions; 1 ml saline (Control), $2{\mu}g$/kg medetomidine (M2), 4 mg/kg tramadol (T4), $2{\mu}g$/kg medetomidine-4 mg/kg tramadol combination (M2T4). Heart rate, blood pressure, respiratory rate, end-tidal carbon dioxide concentration, saturation of hemoglobin with oxygen and body temperature were recorded. After administration of M2 ($0.81{\times}0.18%$), T4 ($0.81{\times}0.14%$) and M2T4 ($0.62{\times}0.12%$), less isoflurane was required than the control value ($1.13{\times}0.19%$). Significantly lower heart rate than the control value was detected after treatment of M2, T4, and M2T4. When only M2T4 was administered, blood pressure was significantly higher than the control value. In conclusion, administrations of tramadol, medetomidine and medetomidine-tramadol combination decreased the MAC of isoflurane in dogs. Especially, medetomidine-tramadol combinations could be useful as a premedication because of the anesthetic sparing effect and moderate changes in cardiovascular system.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.594-600
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• 1989

Primary intracardiac repair of tetralogy of Fallot with low mortality and early good results, has been accomplished in recent years. But palliative procedures have been reserved for those hypoplastic pulmonary arteries, a hypoplastic left ventricle or anomalies of the coronary artery would make total correction difficult. And the Blalock-Taussig shunt operation is recognized as a standard and popular palliative procedure. I undertook a retrospective determination of the effect of the Blalock-Taussig shunt operation on the development of the main pulmonary artery and the right and left pulmonary arteries. Between January, 1980, and April, 1987, at the Severance Hospital, 16 patients were studied by cardiac catheterization and angiocardiography, before undergoing Blalock-Taussig shunting procedures for the palliation of severe symptoms of tetralogy of Fallot, and some time later, usually prior to a second procedure. The mean interval between catheterizations was 22.25 months. Patients with tetralogy of Fallot and pulmonary atresia or with an occluded shunt were not included. The primary and secondary angiograms of each patient were reviewed, and measurements of the diameter of the main pulmonary artery, the right and left pulmonary arteries, and the descending thoracic aorta were taken. The results are as follows; 1. The hematocrit decreased from 56.39% to 50.34%[p< 0.05], and the arterial oxygen saturation increased from 62.00 % to 81.31 %[p< 0.001] following shunt procedures 2. The ratio of the diameter of the right pulmonary artery plus the left pulmonary artery to the diameter of the descending thoracic aorta increased 1.30 k 0.28 times [p< 0.01]; but the ratio of the diameter of the main pulmonary artery to the diameter of the descending thoracic aorta increased 1.10 * 0.33 times, which was not. significant[p< 0.05]. 3. The interval between shunting and second catheterization was not related to the magnitude of change in the pulmonary arteries[r=0.141, p >0.05]. 4. The changes in the ratio of the diameter of the right pulmonary artery plus the diameter of the left pulmonary artery to the diameter of the descending thoracic aorta was inversely related to the initial ratio[r=0.757, p >0.001], but the change in the ratio of the diameter of the main pulmonary artery to the descending thoracic aorta was not related[r=0.059, p >0.05]. 5. There were no differences in enlargement of the pulmonary artery on the side of the shunt [ipsilateral] versus enlargement on the opposite side [p >0.05], nor according to the size of the shunt[p >0.05]. In conclusion, this study suggests that the Blalock-Taussig shunt is effective for the development of the right and left pulmonary arteries but not effective for the main pulmonary artery.

• Economic and Environmental Geology
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• v.44 no.2
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• pp.161-170
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• 2011

The multiphase flow simulator, CHEMPS, was developed based on the fractional flow approach reported in the petroleum engineering literature considering fully three phase flow in physically and chemically heterogeneous media. It is a extension of MPS developed by Suk and Yeh (2008) to include the effect of wettability on the migration of NAPL. The fractional flow approach employs water, total liquid saturation and total pressure as the primary variables. Most existing models are limited to two-phase flow and specific boundary conditions when considering physically heterogeneous media. In addition, these models focused mainly on the water-wet media. However, in a real system, variations in wettability between water-wet and oil-wet media often occur. Furthermore, the wetting of porous media by oil can be heterogeneous, or fractional, rather than uniform due to the heterogeneous nature of the subsurface media and the factors that affect the wettability. Therefore, in this study, the chemically heterogeneous media considering fractional wettability as well as physically heterogeneous media were simulated using CHEMPS. In addition, the general boundary conditions were considered to be a combination of two types of boundaries of individual phases, flux-type and Dirichlet type boundaries.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.785-792
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• 2012

In this paper, a current-voltage characteristics of n-channel junctionless and inversion mode(IM) MuGFET, and p-channel junctionless and accumulation mode(AM) MuGFET has been measured and analyzed for the application in high speed and low power switching devices. From the variation of the threshold voltage and the saturation drain current with the substrate bias voltages, their variations in IM devices are larger than junctionless devices for n-channel devices, but their variations in junctioness devices are larger than AM devices for p-channel devices. The variations of transconductance with substrate biases are more significant in p-channel devices than n-channel devices. From the characteristics of subthreshold swing, it was observed that the S value is almost independent on the substrate biases in n-channel devices and p-channel junctionless devices but it is increased with the increase of the substrate biases in p-channel AM devices. For the application in high speed and low power switching devices using the substrate biases, IM device is better than junctionless devices for n-channel devices and junctionless device is better than AM devices for p-channel devices.

• ALGAE
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• v.19 no.4
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• pp.293-301
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• 2004

A chain-forming toxic din flagellate, Gymnodinium catenatum (Graham) was known as a paralytic toxin-producer among Gymnodinoid group. In the study, the effects of water temperature, salinity and irradiance on the growth of G. catenatum isolated from Yeosuhae Bay, Korea were investigated. Water temperature range in which G. catenatum showed specific growth rate higher than 0.3 day$^{-1}$ were above about 18${^{\circ}C}$. However, salinity did not have such an effect on growth of G. catenatum. The maximum growth rate (0.5 day$^{-1}$) was obtained at 25${^{\circ}C}$ and 30 psu. The specific growth rate (u) expressed as a polynomial equation as functions of temperature (T; ${^{\circ}C}$) and salinity (S; psu) was $\mu$ = 0.005·T$^2$ - 0.0001164 T$^3$ - 0.063-S + 0.005-S$^2$ - 0.00007608-S$^3$ - 0.003-T-S + 0.00005308-T$^2$-S. Thus, in aspects of water temperature and salinity, the species may be expected to survive in most Korean coastal waters from early summer to autumn. The irradiance-growth curve was described as = 0.16 (I - 10.4)/(1 + 21.8) at 18${^{\circ}C}$ and 30 psu, indicating a half-saturation (Ks) photon flux density (PFD) of 42.6$\mu$mol m$^{-2}s^{-1}$ and compensation PFD (I$_0$) of 10.4$\mu$mol m$^{-2}s^{-1}$. These characteristic responses to irradiance suggest that G. catenatum can reside at the sub-surface.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.288-302
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• 2017

Accurate measurement of benthic nutrient fluxes (BNF) is a prerequisite for evaluating the effect of sediments on nutrient cycle in the surface water. The intact sediment cores were collected in July 2015 at the midstream of Nakdong River. We identified pre-incubation time (6, 12, 24 hr), dissolved oxygen concentration (90, 70, 50% saturation), diffusive boundary layer thickness (0, 0.6-0.8, 1.2-1.4 mm), and incubation temperature (10, 17, 20, $25^{\circ}C$) as the most important control factors, and measured the BNF fluctuation with the variation of these factors using the laboratory sediment core incubation method. Since the chemical composition, redox condition, hydrodynamic regimes and microbial activities at the sediment-water interface were changed as a result of the alteration of control factors, sediment core incubation should be conducted under as close to the natural conditions of study site as possible, in order to produce the results similar to actual values. Relative percentage differences between two replicates were below 20% in most control factors, which showed satisfactory precision for strict compliance with the experimental conditions and procedures. In the further studies, we will compare the results of core incubation with those of in situ measurements to confirm the accuracy of the sediment core incubation method.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.269-277
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• 1995

Membrane vesicles were prepared by differential centrifugation from epithelial cells of porcine trachea. Total activity of microsomal ATPases was measured spectrophotometrically by a coupled enzyme assay. The steady-state activity of the enzyme was $329{\pm}10$ nmol/min mg protein. Thapsigargin, a specific antagonist of intracellular $Ca^{2+}-ATPase$, inhibited about 50% of the activity, leaving $178{\pm}18\;nmol/min .mg$ protein (n=6), indicating that the $Ca^{2+}-ATPase$ is one of the major microsomal ATPases. The microsomes used in this study appeared to be tight-sealed vesicles since they showed saturation in $^{45}Ca^{2+}$ uptake experiments. Inositol 1,4,5-trisphosphate $InsP_{3}, 4\;{\mu}M$, an agonist of $InsP_{3}$-sensitive $Ca^{2+}$ release channel ($InsP_{3}$, receptor), and Ca-ionophore A23187 $(10\;{\mu}M)$ induced $^{45}Ca^{2+}$ releases of 20% and 50% of stored $^{45}Ca^{2+}$, respectively. The addition of $(10\;{\mu}M\;InsP_{3}$ also increased the microsomal ATPase activity from $282{\pm}8$ nmol/min mg protein to $334{\pm}21$ nmol/min . mg protein in the intact vesicles. Similar increase in the activity was observed by making microsomes leaky (uncoupling) using the Ca-ionophore A23187. ;$InsP_{3}-induced$ effects were blocked by either thapsigargin or heparin suggesting that: 1) the $InsP_{3}-induced$ increase in ATPase activity is mediated by microsomal $Ca^{2+}-ATPase$, and 2) dissipation of $Ca^{2+}$ gradient across the microsomal membrane is responsible for the $InsP_{3}-induced$ effect. In order to test the dependence of the $Ca^{2+}-ATPase$ activity on the activity of $InsP_{3}-induced$ the activity of ATPases was monitored in various concentrations of free $Ca^{2+}$ using $EGTA-Ca^{2+}$ buffers. The $Ca^{2+}$-dependent biphasic change is the well-known character of $InsP_{3} receptor but not of microsomal $Ca^{2+}-ATPase$ in non-excitable cells; however, the activity of microsomal ATPase appeared biphasic and a maxim진 activity of $397{\pm}36nmol/min\;.mg$ protein was obtained in the solution containing 100 nM free $Ca^{2+}$. Below or above this concentration, the activity of ATPases was lower. These results strongly support a positive correlation of microsomal $Ca^{2+}-ATPase$ to the $InsP_{3}$ receptors in epithelial microsomes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.27-34
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• 2018

Recently, liquid desiccant systems have received attention for the dehumidification of air. LiCl and LiBr are widely used in liquid desiccant systems due to their excellent thermo-physical properties. In this study, dehumidification tests were conducted with Celdek elements using LiCl and LiBr. During the tests, the dry and wet-bulb air temperatures were maintained at $35^{\circ}C$ and $28^{\circ}C$, respectively. The solution temperature was $20^{\circ}C$, the solution concentration was 50%, the solution circulation rate was 50 kg/h, and the frontal air velocity was varied from 2.0 to 4.0 m/s. The results show that the amount of dehumidification increased as the frontal velocity increased. On average, LiCl showed 27% higher dehumidification performance than LiBr, which was probably due to the lower saturation of the absolute humidity of LiCl compared with that of LiBr. On the other hand, LiBr yielded 12% larger pressure drop than LiCl. In general, the Sherwood numbers of LiCl and LiBr were approximately the same, showing that the effect of the desiccant on the Sherwood number was insignificant. Existing correlations highly overpredicted the present Sherwood numbers.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.79-83
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• 2011

Over-application of nitrogen fertilizer keeps increasing the salinity in the soils of greenhouse in domestic agriculture. In order to remove the excess amounts of soil nitrate, soil microorganisms which have high capacity of nitrate uptake were isolated from the upland soils and their nitrate uptake activities were measured. Strain GS2 was able to remove 50 mM nitrate within 12 h. After sequence comparison analysis of 16S rRNA gene, the strain was identified and named as Bacillus sp. GS2. When the growth and nitrate uptake activities were measured, maximal values were obtained at $30-40^{\circ}C$ and $37^{\circ}C$, respectively; however, both were optimal at pH 6-8. In the media containing 50 mM nitrate, Bacillus sp. GS2 removed 43 mM nitrate which is corresponding to 86% removal. Similar amounts of nitrate removal were observed at the nitrate concentrations up to 300 mM, showing a saturation in nitrate uptake at concentrations above 50 mM. These results imply that Bacillus sp. GS2 can be a good candidate for the microbial remediation of accumulated environmental nitrate because of its excellent growth and nitrate uptake activity.