• Analytical Science and Technology
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• v.24 no.6
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• pp.467-476
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• 2011

Solubility data of carbon dioxide ($CO_2$) in the imidazolium-based ionic liquids with methylsulfate anion are presented at pressures up to about 45 MPa and at temperatures between 303.15 K and 343.15 K. The ionic liquids studied in this work were 1-ethyl-3-methylimidazolium methylsulfate ([emim][$mSO_4$]), 1-butyl-3-methylimidazolium methylsulfate ([bmim][$mSO_4$]). The solubilities of $CO_2$ were determined by measuring the bubble point or cloud point pressures of the binary mixtures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The equilibrium pressure increased very steeply at high $CO_2$ compositions. The $CO_2$ solubility in ionic liquids increased with increase of the total length of alkyl chains attached to the imidazolium cation of the ionic liquids. The phase equilibrium data for the $CO_2$ + ionic liquid systems have been correlated using the Peng-Robinson equation of state.

• Clean Technology
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• v.11 no.3
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• pp.147-152
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• 2005

For estblishing the best technique for the micronization of Ibuprofen using supercritical fluids, the solubility should be known. The solubility of Ibuprofen in supercritical carbon dioxide was measured by observing the cloud point. The cloud point was observed using high pressure equipment equipped a variable volume view cell between temperature of 35, 40 and $45^{\circ}C$. The solubility data was correlated by the Peng-Robinson equation of state Solute physical properties, such as critical temperature (Tc), critical pressure (Pc) and acentric factor (${\omega}$) were estimated by the some group contribution method. As pressure was increased, the solubility increased at constant temperature. The retrograde phenomenon by a solute vapor pressure and a density of solvent was observed at the pressure of around 150bar. It was found that $CO_2$ can be used as a supercritical solvent in micronization of ibuprofen by RESS.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.763-767
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• 2010

High-pressure phase behavior for the binary mixture of 1-propanol with supercritical $CO_2$ has been measured by means of a high-pressure phase equilibrium apparatus equipped with a variable-volume view cell. The equilibrium loci of the pressure - composition and pressure - temperature were obtained for the binary mixture of 1-propanol + $CO_2$ system at 305.15 K, 313.15 K, 323.15 K and 333.15 K, and from 2 MPa to 11 MPa. The critical temperature of the mixture increased with the temperature. The pressure-composition line for the binary mixture of $CO_2$-1-propanol system showed a typical type-II phase behavior. The experimental P-x envelopes were correlated by using the Peng-Robinson equation of state in a satisfactory manner to obtain the parameters with $k_{ij}=0.116$ and ${\eta}_{ij}=-0.065$.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.225-229
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• 2017

Micron-sized dextran particles, which now attract wide attention as a promising drug delivery systems, can be prepared via the supercritical anti-solvent (SAS) process. In SAS process, dextran particles are obtained as a result of recrystallization of dissolved dextran in dimethyl sulfoxide (DMSO) on addition of supercritical $CO_2$ as an anti-solvent. In this work, with an intention to provide information on the feasible operating conditions of the process, the phase behavior of Dexran/DMSO/$CO_2$ is observed by measuring the cloud point in favor of a variable volume cell. From the experimental study, it is concluded that a feasible operating condition of the SAS process for preparation of dextran particles would be 300.15 K~330.15 K and 90 bar~130 bar, respectively, and solute concentration ranges from 5mg/ml to 20 mg/ml.

• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.205-212
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• 2000

The relation of food and supplemental intake of iron, vitamin E and ascorbic acid and other lifestyle variables to packed cell volume (PCV) and serum vitamin levels was studied in urban and rural (71% Amish) communities. Subjects were interviewed (24-h dietary recalls) on three occasions over 18-months, and blood samples were taken (maximum observations = 442). Mean PCV was lower in rural males (43.3) than in urban males (45.4) despite higher man food iron intake (18.7 and 14.4 mg/day, respectively). Mean meal iron availability was higher at lunch and lower at breakfast and dinner for rural than for urban subjects. Smoking was the number one variable in males and females explaining variance in PCV. Supplemental vitamin E and ascorbate intakes explained the most variance in serum vitamin E and ascorbate levels, respectively. Serum vitamin E was also associated with supplemental ascorbate intake (r=0.29). Serum ascorbate was also associated with food ascorbate intake (r=0.28) and body weight (r=-0.24).

• Journal of Electrochemical Science and Technology
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• v.12 no.4
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• pp.406-414
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• 2021

Electrochemical devices are constructed for continuous syngas (CO + H₂) production with controlled selectivity between CO₂ and proton reduction reactions. The ratio of CO to H₂, or the faradaic efficiency toward CO generation, was mechanically manipulated by adjusting the space volume between the cathode and the polymer gas separator in the device. In particular, the area added between the cathode and the ion-conducting polymer using 0.5 M KHCO₃ catholyte regulated the solution acidity and proton reduction kinetics in the flow cell. The faradaic efficiency of CO production was controlled as a function of the distance between the polymer separator and cathode in addition to that manipulated by the electrode potential. Further, the electrochemical CO₂ reduction device using Au NPs presented a stable operation for more than 23 h at different H₂:CO production levels, demonstrating the functional stability of the flow cell utilizing the mechanical variable as an important operational factor.

• Journal of computational fluids engineering
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• v.18 no.4
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• pp.25-34
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• 2013

A numerical study of a laminar natural convection of the CuO-water nanofluid in a square cavity using the Buongiorno's nonhomogeneous model is presented. All the governing equations including the volume fraction equation are discretized on a cell-centered, non-uniform grid employing the finite-volume method with a primitive variable formulation. Calculations are performed over a range of Rayleigh numbers and volume fractions of the nanopartile. From the computed results, it is shown that both the homogeneous and nonhomogeneous models predict the deterioration of the natural convection heat transfer well with an increase of the volume fraction of nanoparticle at the same Rayleigh number, which was observed in the previous experimental studies. It is also shown that the differences in the computed results of the average Nusselt number at the wall between the homogeneous and nonhomogeneous models are very small, and this indicates that the slip mechanism of the Brown diffusion and thermophoresis effects are negligible in the laminar natural convection of the nanofluid. The degradation of the heat transfer with an increase of the volume fraction of the nanoparticle in the natural convection of nanofluid is due to the increase of the viscosity and the decrease of the thermal expansion coefficient and the specific heat. It is clarified in the present study that the previous controversies between the numerical and experimental studies are owing to the different definitions of the Nusselt number.

• Biomedical Science Letters
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• v.22 no.1
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• pp.9-17
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• 2016

Unfortunately, the five-year survival rate of lung cancer is relatively low compared with other cancers. Therefore, better predictors are need for prognosis, therapeutic strategy, risk stratification and predicting long-term mortality of lung cancer. Recently, increasing data suggest that Glasgow Prognostic Score (GPS) and procalcitonin levels are useful predictor cancer prognosis. In this study, we retrospectively investigated the correlation of GPS or procalcitonin to clinical variables in patients with pretreatment lung cancer. In 135 patients with pretreatment lung cancer, GPS, procalcitonin, demographic characteristics, hematological, coagulation, biochemical, inflammatory and cardiac markers were measured. Monocyte, eosinophil, basophil, neutrophil to lymphocyte ratio, red cell distribution width (RDW), platelet to lymphocyte ratio, mean platelet volume to platecrit ratio, D-dimer and prothrombin time (PT) levels were higher, whereas mean platelet volume was lower than their normal ranges. Glucose and sodium levels were low, whereas gamma glutamyl transferase (GGT), total bilirubin, creatinine and inorganic phosphorus concentrations were increase compared their normal ranges. Procalcitonin, high sensitivity C-reactive protein and troponin-I concentrations were elevated compared with their normal ranges. GPS had significantly positive or negative relations to cancer stage, hematological, coagulation, biochemical, inflammatory and troponin-I. Based on the data, we suggest that GPS may be a potent and useful predictor for prognosis, therapeutic strategy, risk stratification and predicting long-term mortality of lung cancer.

• Membrane Journal
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• v.26 no.2
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• pp.141-145
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• 2016

Polymer electrolyte membranes (PEMs) are key components to determine electrochemical fuel cell performances, in addition to electrode materials. The PEMs need to satisfy selective transport behaviors to small molecules including gases and protons; the PEMs have to transport protons as fast as possible, while they should act as hydrogen barriers, since the permeated gas induces the thermal degradation of cathode catalyst, resulting in rapid electrochemical reduction. To date, limited tools have been used to measure how fast hydrogen gas permeates through PEMs (e.g., Constant volume/variable Pressure (time-lag) method). However, most of the measurements are conducted under vacuum where PEMs are fully dried. Otherwise, the obtained hydrogen permeance is easily changeable, which causes the measurement errors to be large. In this study, hydrogen permeation properties through Nafion212 used as a standard PEM are evaluated using an in-situ measurement system in which both temperature and humidity are controlled at the same time.

• Journal of the Korean Society of Radiology
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• v.84 no.2
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• pp.441-453
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• 2023

Purpose To evaluate the development, location, and volume of a VX2 carcinoma using four inoculation methods in a rabbit brain. Materials and Methods Inoculation of a VX2 cell suspension was performed 1) on the appointed day, 2) seven days after storing a VX2 carcinoma in a freezer or 3) seven days after storing a VX2 carcinoma in a deep freezer after sacrificing the donor rabbits. 4) Without sacrificing the rabbits, the VX2 cell suspension was obtained using a gun biopsy, inoculation was performed on the appointed day. MR imaging was performed 10 days after inoculation. Brain tissues were obtained the day after. The development, location, and volume of the tumor were evaluated. Results Seventeen of the 18 rabbits inoculated on the appointed day developed tumors (average tumor volume, 106.32 mm³). One of five inoculated seven days after storing the VX2 tumor in the freezer, and three of five inoculated seven days after storing the VX2 tumor in the deep freezer developed tumors. Inoculation with a VX2 cell suspension obtained with a gun biopsy from five rabbits revealed development of tumors in only two rabbits. The tumors mostly developed in the superficial cortex. Conclusion TVX2 rabbit brain tumor model is easy to develop and revealed variable reproducibility. This model can be applicable in radiologic imaging, treatment planning, interventional treatment and drug delivery research. VX2 cell can be successfully innoculated into the brain using variable methods under researcher's variable conditions.