• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.11
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• pp.1031-1037
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• 2000

Isothermal vapor-liquid equilibrium(VLE) data have been obtained for the systems of propane(R290)+1,1,1,2-tetrafluoroethane(R134a) and 1,1,1,2-tetrafluoroethane(R134a)+isobutane(R60A) in the temperature range of 253.15 to 323.15K. Experiments were performed in a circulation type apparatus by injecting vapor through liquid pool using a magnetic pump. Both systems form azeotropes in the temperature range of this study. The experimental results were estimated with the Peng-Robinson equation of state. When the temperature-dependent binary interaction parameter was used in the Peng-Robinson equation of state, the absolute average deviation of the measured bubble point pressures from the values correlated by the Peng-Robinson equation was 0.65% and 0.78% for R290+R134a and R134a+600a, respectively. Azeotropic compositions for both systems were presented.

• Current Optics and Photonics
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• v.7 no.1
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• pp.83-89
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• 2023

This study reports a structure, based on a liquid-crystal (LC) core optical waveguide, for the switchable spatial control of linearly polarized light. The refractive indices of both left and right isotropic claddings in the waveguide are between the two principal-axis indices of the nematic liquid crystal (NLC). Numerical simulations demonstrate that the proposed structure can be operated in transmission mode or as an attenuator by controlling the on and off states of the applied voltage, whether the initial excitation is transverse electric (TE) linearly polarized light or transverse magnetic (TM) linearly polarized light. The design can also be used as an integrated optical polarizer, since only one type of linearly polarized light is always permitted to pass through the core zone of the NLC optical waveguide.

• Electrical & Electronic Materials
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• v.8 no.5
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• pp.633-639
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• 1995

Dropouts in magnetic media are a primary quality deficiency which is detrimental to magnetic signal quality and thus the major impediment to error-free recording, especially in high density digital recorders. The specific form of defects and causes found to be responsible for signal dropouts occurring in magnetic tape were studied. Dropout occurred when the RF signal falls to low level due to the various types of surface defects. However, the fall in the level of the RF signal in gravure roll coated tapes was most often caused by foreign particles adhering to the magnetic tape. It was also shown from the present study that scattered particles trapped under the tape surface or put on the top can lift it as it crosses the head, creating a spherical tent shaped defect and causing a temporary signal drop. Dropout producing substances were identified through optical and microchemical analyses. The results were correlated with measured electrical signal losses combined with analytical microscopy to clarify source identification of defects.

• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.1-6
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• 1998

The influence of the order-disorder structural transition on the magnetic and mageto-optical, and transport properties of Fe-Al and Co-Al alloy films has been investigated. The disordered states in the alloy films were prepared by vapor quenching deposition on glass substrates cooled by liquid nitrogen. The experimental study of the magento-optical properties of the ordered and disordered Fe-Al and Co-Al alloy films has been carried out in 1.05-5.0 eV energy range at room temperature. The transport properties have been measured in 2-300K temperature range with and without magnetic field of 0.5T. The influence of the order-disorder structural transition on the magnetic and magneto-optical properties was discussed by using the effective medium approximation and the structural defect approach. That on the temperature dependence of the resistivity was analyzed in a framework of the partial localization of the electronic states and the variable range hopping conductivity.

• Journal of The Korean Society of Clinical Toxicology
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• v.20 no.2
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• pp.82-85
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• 2022

Traditionally, most cases of nicotine poisoning have been due to ingestion of nicotine pesticides. However, the increasing use of electronic cigarettes (e-cigarettes) has resulted in both intentional and unintentional exposure to concentrated liquid nicotine or "e-liquid" leading to an increase in nicotine poisoning cases. However, fatalities following the ingestion of the e-liquid are extremely rare. We report a rare case of cardiac arrest and severe encephalopathy following the intentional ingestion of e-liquid. We present the case of a 20-year-old woman who intentionally ingested liquid nicotine intended for e-cigarette use. She was found in asystole and experienced a return of spontaneous circulation (ROSC) after undergoing approximately 46 mins of cardiopulmonary resuscitation. Her plasma nicotine levels were >500 ng/ml. Despite aggressive supportive care, she was found to have encephalopathy consistent with severe anoxic brain injury on magnetic resonance imaging. In recent times, there have been some reports of deaths following liquid nicotine ingestion. Our case illustrates the potential for fatal nicotine toxicity from ingestion of e-cigarettes.

• Progress in Superconductivity and Cryogenics
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• v.20 no.4
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• pp.1-5
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• 2018

A high gradient magnetic (HGM) separator prototype with the $2^{nd}$ generation high temperature superconducting (2G HTS) magnetic system operated in sub-cooled nitrogen is presently under development at NRC "Kurchatov Institute" (Moscow, Russia). The main goal of the project is an attempt to shift away from the complicated liquid helium cryostats towards simple cryocooler-based nitrogen cryogenics as much more convenient for HGM separators industrial applications. Using of commercial HTS tapes allows to get a sufficient level of magnetic fields and extraction forces with low energy consumption. The expected operational parameters of the device are 1.2-1.5 T in the empty operational gap and up to 3 T on the ferromagnetic filters. In this paper we briefly describe the design of the HTS rotary separator prototype with the horizontally oriented rotor axis and propose different types of ferromagnetic filters intended for weakly magnetic ores enrichment.

• Progress in Superconductivity
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• v.13 no.1
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• pp.1-6
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• 2011

Measurement of magnetic signals generated from electric activity of myocardium provides useful information for the functional diagnosis of heart diseases. Key technical component of the magnetocardiography (MCG) technology is SQUID. To measure MCG signals with high signal-to-noise ratio, sensitive SQUID magnetic field sensors are needed. Present magnetic field sensors based on Nb SQUIDs have field sensitivity good enough to measure most of MCG signals. However, for accurate measurement of fine signal pattern or detection of local atrial fibrillation signals, we may need higher field sensitivity. In addition to field sensitivity, economic aspect of the SQUID system is also important. To simplify the SQUID readout electronics, the output voltage or flux-to-voltage transfer of SQUID should be large enough so that direct measurement of SQUID output can be done using room-temperature preamplifiers. Double relaxation oscillation SQUID (DROS), having about 10 times larger flux-to-voltage transfers than those of DC-SQUIDs, was shown to be a good choice to make the electronics compact. For effective cancellation of external noise inside a thin economic shielded room, first-order axial gradiometer with high balance, simple structure and long-baseline is needed. We developed a technology to make the axial gradiometer compact using direct bonding of superconductive wires between pickup coil and input coil. Conventional insert has mechanical support to hold the gradiometer array, and the dewar neck has equal diameter with the dewar bottom. Boiling of the liquid He can generate mechanical vibrations in the gradiometer array due to mechanical connection structure. Elimination of the mechanical support, and direct mounting of the gradiometer array into the dewar bottom can reduce the dewar neck diameter, resulting in the reduction of liquid He consumption.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.606-611
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• 2003

Byakangelicin, 9-(2,3-dihydroxy-2-methylbutoxy)-4-methoxy-7H- furo[3,2-g][l]benzopyran-7-one (BKG), a component of Angelicae dahuricae Radix, is considered to be an inhibitor of aldose reductase for the treatment of diabetic cataract. An analytical method for the isolation of BKG developed by high-performance liquid chromatography has been reported. No literature on the metabolism of BKG, however, has been found. With the purpose of identifying new metabolites of BKG, BKG (100 mg/kg) was orally administered to Sprague-Dawley rats via a gavage. Using a metabolic cage, urine was collected for 24 h, and the urine samples were extracted by liquid-liquid extraction. For structural identification of new urinary metabolites of BKG, various instrumental analyses were conducted by gas-chromatography/mass spectrometry, high-performance liquid chromatography/diode array detector, liquid chromatography/mass spectroscopy with thermospray interface and $^1H$ nuclear magnetic resonance spectroscopy. Two metabolites produced from the Ο-demethylation or Ο-dealkylation of BKG were newly identified, and another new but unknown metabolite was assumed to be the hydroxylated form of BKG. These results indicate that the major metabolic products of BKG are formed by Ο-demethylation or Ο-dealkylation of BKG side chains.

• Elastomers and Composites
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• v.54 no.1
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• pp.14-21
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• 2019

Main-chain/side-chain liquid crystalline polymers (MCSCLCPs) combined with an azobenzene group and a cholesteryl group were synthesized to impart light and temperature sensitivity to the polymer. The polymers were designed with the azobenzene unit as the mesogenic group of the main-chain and various compositions of the azobenzene and cholesteryl units as the mesogenic group of the side-chain. The chemical structures and physical properties of the synthesized polymers were investigated by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, differential scanning calorimetry, thermogravimetric analysis, polarized optical microscopy, and ultraviolet-visible (UV-Vis) spectroscopy. All the MCSCLCPs were amorphous and exhibited enantiotropic liquid crystal phases; these polymers achieved the nematic phase with increasing content of the azobenzene group and exhibited the cholesteric phase with weak liquid crystallinity as the content of the cholesteryl group was increased. Furthermore, the polymers containing the azobenzene group showed photoisomerization when exposed to UV-Vis light, and the CP-A3C7 and CP-A5C5 polymers exhibited thermochromism in the temperature range of the liquid crystal phase.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.4 no.1
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• pp.121-131
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• 2000

Melt flow, heat and mass transfer of oxygen have been analyzed numerically in the process of Czochralski single crystal growth of silicon under the influence of misaligned cusp magnetic fields. Since the silicon melt in a crucible for crystal growth is of high temperature and of highly electrical-conducting, experimentation method has difficulty in analyzing the behavior of the melt flow. A set of simultaneous nonlinear equations including Navier-Stokes and Maxwell equations has been used for the modelling of the melt flow which can be regarded as a liquid metal. Together with the melt flow which forms the Marangoni convection, a flow circulation is observed near the comer close both to the crucible wall and the free surface. The melt flow tends to follow the magnetic lines instead of traversing the lines. These flow characteristics helps the flow circulation exist. Mass transfer characteristics influenced by the melt flow has been analyzed and the oxygen absorption rate to the crystal has been calculated and turned out to be rather uniform than in the case of an aligned magnetic field.