• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1649-1654
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• 2009

Induction motors widely use in industry because structure is simple and hard and cost is generally cheap and they are easy to control. In recently, because of saving steel, ventilation and benefit of frame fixing, rectangular core type induction motors use in industry more and more. This paper presents current characteristic according to stator core cutting degree in three-phase induction motor (IM) with rectangular stator core. According to stator cutting degree, magnetic saturation and paths of flux are changed. Because of these situations, phase currents are unbalance and are produced harmonic components and they cause decrease of efficiency. We analyze each $10^{\circ}$ from $0^{\circ}$ to $30^{\circ}$ using 2-D finite element analysis (FEA). Optimal stator cutting core degree selection supplies stable currents and efficiency improvement. In this paper, loss separation test was executed by IEEE Std. 112-98 Method B and we compare with the result of loss separation by Simulation using FEM and by Experiment.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.825-828
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• 2010

To classify Glycyrrhiza species, samples of different species were analyzed by $^1H$ NMR-based metabolomics technique. Partial least squares discriminant analysis (PLS-DA) was used as the multivariate statistical analysis of the 1H NMR data sets. There was a clear separation between various Glycyrrhiza species in the PLS-DA derived score plots. The PLS-DA model was validated, and the key metabolites contributing to the separation in the score plots of various Glycyrrhiza species were lactic acid, alanine, arginine, proline, malic acid, asparagine, choline, glycine, glucose, sucrose, 4-hydroxy-phenylacetic acid, and formic acid. The compounds present at relatively high levels were glucose, and 4-hydroxyphenylacetic acid in G. glabra; lactic acid, alanine, and proline in G. inflata; and arginine, malic acid, and sucrose in G. uralensis. This is the first study to perform the global metabolomic profiling and differentiation of Glycyrrhiza species using $^1H$ NMR and multivariate statistical analysis.

• KSBB Journal
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• v.25 no.5
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• pp.466-470
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• 2010

In this study, we developed simple process for ethanol concentration. We developed magnetically separable polyanilline nanofiber (PAMP) for selective ethanol adsorption. PAMP can adsorbed 80% of ethanol in the solution. After adsorption, the ethanol was recovered with simple magnetic separation and centrifugation process. After 10 times recycle of PAMP, the ethanol adsorption maintained 92% of its initial adsorption capacity. Using ethanol concentration process, the ethanol concentration increased up to 197.6 g/L from 46 g/L which was 4.3 folds increase.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.590-597
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• 2003

Processing and smelting of copper containing sulphide concentrates result in the accumulation of impurities into various process streams. All primary copper smelters and refineries around the world produce significant amounts of slag, dust, sludge, residues and others, which contain copper and precious metals. The recovery of these valuable metals is essential to the overall economics of the smelting process. Physical, chemical and mineralogical characterization of particular slag and Cottrell dusts from primary smelters and $Dor\'{e}$ furnace (TBRC) slag and Pressure Leached Anode slimes from a copper refinery have been carried out to understand the basic behind the recovery processes. Various process options have been evaluated and adapted for the treatment of slag from different smelting furnaces and Cottrell dusts as well as the intermediate products from copper refineries. Besides the hydro- or pyro-metallurgical treatments, the above mentioned physical separation options such as magnetic, gravity separation, flotation and precipitation flotation processes have been successfully identified and adapted as the possible process options to produce a Cu-rich or precious metal-rich concentrates for in-house recycling and other valued by-product for further treatment. The results of laboratory, pilot plant and production operations are presented, and incorporation of several alternative flowsheet is discussed in this paper.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2003.10a
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• pp.22-34
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• 2003

Processing and smelting of copper containing sulphide concentrates result in the accumulation of impurities into various process streams. All primary copper smelters and refineries around the world produce significant amounts of slag, dust, sludge, residues and others, which contain copper and precious metals. The recovery of these valuable metals is essential to the overall economics of the smelting process. Physical, chemical and mineralogical characterization of particular slag and Cottrell dusts from primary smelters and Dore furnace (TBRC) slag and Pressure Leached Anode slimes from a copper refinery have been carried out to understand the basic behind the recovery processes. Various process options have been evaluated and adapted for the treatment of slag from different smelting furnaces and Cottrell dusts as well as the intermediate products from copper refineries. Besides the hydro- or pyre-metallurgical treatments, the above mentioned physical separation options such as magnetic, gravity separation, flotation and precipitation flotation processes have been successfully identified and adapted as the possible process options to produce a Cu-rich or precious metal-rich concentrates for in-house recycling and other valued by-product for further treatment. The results of laboratory, pilot plant and production operations are presented, and incorporation of several alternative flowsheet is discussed in this paper.

• Resources Recycling
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• v.12 no.3
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• pp.3-12
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• 2003

Physical separation containing grinding, sieving, dry magnetic separation and air classification were carried out in order to recover Ta anode from waste Ta condenser. Roll crusher wat used for the liberation of resin and metals in closed circuit system. The liberation between Ta anode and resin was easily achieved, whereat some of metals did not liberated from the Ta anode when the waste condenser was crushed below 8 mesh. When the crushed sample were divided into 8/10 mesh, 10/18 mesh and -18 mesh, metals was mainly remained in 8/10 mesh in contrast to Ta anode was in +18 mesh. It was shown that resin was more easily crushed rather than metals from the result of that resin content was 71.5％ in -18 mesh. The liberation efficiency was different with the input size of the crushed sample and average efficiency was 62.3% due to the locked Ta anode particles. The results of air classification test for the crushed samples showed that optimal air flow are 39㎥/h, 32㎥/h, 20㎥/h. respectively. When the sample were separated with optimal condition, 94.45％ Ta anode containing 97.47 wt.％ Ta anode, 0.93 wt.％ resin. 1.61 wt.％ metal was recovered with 49.39 wt.％ yield.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.638-642
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• 2012

Human pathogenic viruses such as hepatitis A and E virus (HAV and HEV), which lead to acute liver failure and death, are foodborne pathogens associated with the consumption of virus-contaminated meats, filter-feeding bivalves, fruits, and salads. Two of the three swine farms examined in this study had HAV and HEV positive stool samples in a nested RT-PCR assay. The use of the immunomagnetic separation (IMS) facilitated the separation of HAV through interactions between the ligand on the virion surface and the antibody from the swine feces containing both HAV and HEV. The nested RT-PCR analysis was performed for the detection of HAV obtained from hepatocarcinoma cell line (PLC/PRF/5) contaminated with eluent fraction of IMS. This indicated that IMS has the potential to simultaneously isolate and concentrate target viruses by changing antibodies linked on the magnetic beads.

• Resources Recycling
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• v.12 no.6
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• pp.57-63
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• 2003

In this study, the separation of neodymium was investigated from NdFeB permanent magnet scrap. Decomposition and leach-ing process of NdFeB permanent magnet scrap by oxidation roasting and sulfuric arid leaching were examined. Neodymium could be separated from iron by double salt precipitation using sodium sulfate. The optimum conditions established for decom-position and leaching are as follows: oxidation roasting temperature is $500^{\circ}C$ for sintered scrap and $700^{\circ}C$ for bonded scrap, concentration of sulfuric acid in leaching solution is 2.0 M, leaching temperature and time is $50^{\circ}C$ and 2 hrs, and pulp density is 15%. The leaching yield of neodymium and iron was 99.4% and 95.7% respectively. The optimum condition for separation of neodymium by double-salt precipitation was 2 equivalents of sodium sulfate and $50^{\circ}C$ The yield of neodymium was above 99.9%.

• Resources Recycling
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• v.2 no.4
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• pp.33-41
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• 1993

In recovering copper from the copper converter slag, various separation methods, such as flotation, sieving and magnetic separation had been tried. The copper converter slag used in this study was prepared in two ways, i.e. 2 hour cooled and 10 hour cooled. From the flotation of copper slag, 45% Cu concentrate is obtained and the amount of copper recovery is about 93%. Before the flotation, copper in the slag could be also pre-recovered using sieving and separation. It is also found that as the content of copper in the concentrate increa-ses, that of arsenic increase, while zinc and iron contents decrease.

• Geophysics and Geophysical Exploration
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• v.5 no.3
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• pp.157-168
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• 2002

Improved procedures were implemented in the production of the lithospheric magnetic anomaly map from Magsat satellite magnetometer data of East Asia between $90^{\circ}E-150^{\circ}E$ and $10^{\circ}S-50^{\circ}N$. Procedures included more effective selection of the do·it and dawn tracks, ring current correction, and separation of core field and external field effects. External field reductions included an ionospheric correction and pass-by-pass correlation analysis. Track-line noise effects were reduced by spectral reconstruction of the dusk and dawn data sets. The total field magnetic anomalies were differentially-reduced-to-the-pole to minimize distortion s between satellite magnetic anomalies and their geological sources caused by corefield variations over the study area. Aeromagnetic anomalies were correlated with Magsat magnetic anomalies at the satellite altitude to test the lithospheric veracity of anomalies in these two data sets. The aeromagnetic anomalies were low-pass filtered to eliminate high frequency components that may not be shown at the satellite altitude. Although the two maps have a low CC of 0.243, there are many features that are directly correlated (peak-to-peak and trough-to-trough). The low CC between the two maps was generated by the combination of directly- and inversely-correlative anomaly features between them. It is very difficult to discriminate directly, inversely, and nully correlative features in these two anomaly maps because features are complicatedly correlated due to the depth and superposition of the anomaly sources. In general, the lithospheric magnetic components were recovered successfully from satellite magnetometer observations and correlated well with aeromagnetic anomalies in the study area.