• Resources Recycling
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• v.24 no.6
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• pp.9-16
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• 2015

In a recycling scheme of spent lithium ion batteries, a co-precipitation process for the re-synthesis of precursor is essential after the leaching of lithium ion battery scraps. In this study, the effect of ammonia as impurity during the co-precipitation process was investigated in order to re-synthesize a precursor of Ni-rich cathode active material $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ (NCM 622). As ammonia concentration increases from 1 M (the optimum condition for synthesis of the precursors based on 2 M of metal salt solution) to 4 M, the composition of obtained precursors deviates from the designed composition, most notably for Ni. The Ni co-precipitation efficiency gradually decreases from 100% to 87% when the concentration of ammonia solution increases from 1 M to 4 M. Meanwhile, the morphological properties of the obtained precursors such as sphericity, homogeneity and size distribution of particles were also investigated.

• Journal of the Korean Society for Heat Treatment
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• v.14 no.1
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• pp.27-34
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• 2001

The effects of pre-heat treatment(Q/T) on microstructure and hardness of STD11 and STD61 tool steel nitrided by micro-pulse plasma were investigated. The quenching temperature for obtaining matrix hardness of STD11 and STD61 steel on range of HRC 50 to HRC 60 desired for machine parts is about $1070^{\circ}C$ and $1020^{\circ}C$ respectively. The hardness of STD11 and STD61 quenched at the temperature was HRC 63 and HRC 56 respectively. The nitrided case depth of STD11 and STD61 nitrided at $550^{\circ}C$ for 5 hours was independent of pre-heat treatment condition and the depth was approximately $100{\mu}m$. However, hardness and compactness of nitrided layer on Q/T treated specimen were higher than the annealed specimen. The case depth increased linearly with the increase of nitriding temperature, however, the hardness of nitrided layer decreased with the increase of temperature. Phase mixture of ${\gamma}-Fe_4N$ and ${\varepsilon}-Fe_{2-3}N$ was detected by XRD analysis in the nitrided layer formed at the optimum nitriding condition. The optimum nitriding temperature was approximately $490^{\circ}C$ which was $10^{\circ}C$ lower than the tempering temperature for preventing softening behavior of STD11 and STD61 matrix during nitriding process and the surface hardness of nitrided layer obtained by optimum pre-heat treatment condition was about Hv1400.

• Economic and Environmental Geology
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• v.47 no.3
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• pp.265-273
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• 2014

Unconventional resources are natural resources which require greater than industry-standard levels of technology or investment to exploit the commercial development. The key point is that unconventional resources are lower quality fuel sources and are not as economically viable as crude oil and conventional gas. Over the past 100 years, Conventional oil and gas has been satisfied with the energy demands. But developing countries such as China and India, the introduction of the developed countries and the surge of energy due to the depletion of unconventional energy resources will be the limelight. According to be analyzed in the academic literature to unconventional gas and oil(2000~2012) by the program of 'web of science', the research activities 402 papers in unconventional gas and 1,581 papers in unconventional oil.

• Resources Recycling
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• v.26 no.4
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• pp.26-33
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• 2017

The behavior on the solvent extraction of heavy rare earths (HRE) by using PC88A was confirmed to demonstrate the possibility of recovery on the HRE from industrial wastewater, which consist of low concentration rare earth. We verified the extraction behavior of the HRE through a change of equilibrium pH, extractant concentration and A/O ratio, and also confirmed the stripping behavior depending on the type of mineral acids. At equilibrium pH 1.0, extraction of rare earth (RE) was completed from 95% to 100%. In all extraction conditions, it tend to be extracted in order of high atomic number. When A/O ratio was 10/1, Yb and Tm were concentrated at the maximum and increased 6-fold and 3-fold compared to initial concentration, respectively. To confirm the stripping behavior of the RE, three mineral acids were applied to the organic phase and consequently rate of stripping was increased in order of $HNO_3$, $H_2SO_4$ and HCl.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.1
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• pp.32-42
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• 2024

This study compared the results of hemolyzed samples and re-collected samples to investigate a hemolysis influence and an acceptable hemolysis index (HI). Before and after hemolysis, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), amylase (Amy), direct bilirubin (D-bil), total bilirubin (T-bil), creatine phosphokinase (CK), gamma glutamyl transferase (GGT), iron, potassium (K), lactate dehydrogenase (LDH), magnesium (Mg), phosphorus (Phos), total protein (TP), and uric acid (UA) showed significant results in the paired t-test. LDH, K, iron, AST, CK, GGT, TP, Amy and Phos had a high correlation between the degree of hemolysis and the results of samples. When comparing Roche's cut-off HI with HI^QChigh obtained using quality control (QC) high standard deviation (SD), AST, D-bil, CK, and LDH were similar, but Amy, GGT, K, iron, Phos, and TP were lower than the cut-off HI of Roche, while ALP and ALT were higher. Some analytes which showed no significant results in the paired t-test, were found to have significant results in HI>200. Hence, it is suggested that the hemolyzed sample should be rejected if HI>200. Based on this study that some analytes were affected when HI<100, we recommend to set the standard of hemolysis starting from HI>50.

• Korean journal of food and cookery science
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• v.26 no.1
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• pp.13-17
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• 2010

The antioxidant activity of commercial sweet persimmon wine concentrate (SPWC) was evaluated by determining the total phenol content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power (RP), and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities. TPC in the SPWC was $9.29{\pm}0.11\;mg$ gallic acid equivalents (GAE)/g, which corresponds to 31.59 mg GAE/100 mL of the wine. The IC50 for the DPPH radical scavenging activity, RP, and ABTS radical scavenging activity of SPWC were 2.96, 1.44, and 0.48 mg/mL, respectively. The neuroprotective effect of SPWC against glutamate-induced neurotoxicity in N18-RE-105 cells was investigated. Treatment of N18-RE-105 cells with various SPWC concentrations under glutamate resulted in the induction of a protective effect in a dose-dependent manner, as determined by the MTT reduction assay. These results suggest that SPWC exhibits considerable antioxidant and neuroprotective activity.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1096-1107
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• 2019

This study on the physicochemical property of physiological activity substance in mung bean (Phaseolus aureus L.) was performed for the use as an functional food materialization. The proximate composition in the vacuum freeze dried mung bean was carbohydrate 57.20±0.29%, crude protein 26.40±0.69%, moisture 9.90±0.16%, crude ash 3.54±0.43%, and crude fat 2.96±0.26%, respectively. The vitamin content of mung bean was vitamin B₅ 0.62±0.013 mg/100 g, vitamin E 0.17±0.001 mg/100 g, vitamin B₁ 0.13±0.016 mg/100 g, and β-carotene 87.37±0.754 ㎍ RE/100 g, respectively. The mineral content of mung bean was potassium (K) 12,428.55±147.55 mg kg^-1, magnesium (Mg) 2,053.32±14.13 mg kg^-1, calcium (Ca) 1,966.40±14.53 mg kg^-1, sodium (Na) 1,063.99±7.75 mg kg^-1, iron (Fe) 63.77±0.98 mg kg^-1, and manganese (Mn) 14.67±0.22 mg kg^-1. The compositions of fatty acid were saturated fatty acid 29.23±0.03%, monoenes 20.30±0.04%, and polyenes 50.46±0.06%. Protein bound amino acid content of mung bean was 21.75±0.24 g%. And major amino acids were glutamic acid 3.93±0.03 g%, aspartic acid 2.68±0.03 g%, respectively. The composition of free amino acid of mung bean was 336.77±8.66 mg%, and major free amino acids were arginine, glutamic acid, asparagine, and aspartic acid. As a results of these experiment, Mung bean could be used a natural resouce and functional biohealth food substance.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.62-68
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• 2016

Purpose In a cyclosporine experiment using a robotic liquid handing system has found a deviation of its standard curve and low reproducibility of patients's results. The difference of the test is that methanol is mixed with samples and the extractions are used for the test. Therefore, we assumed that the abnormal test results came from using methanol and conducted this test. In a manual of a robotic liquid handling system mentions that we can choose several setting parameters depending on the viscosity of the liquids being used, the size of the sampling tips and the motor speeds that you elect to use but there's no exact order. This study was undertaken to confirm pipetting ability depending on types of liquids and investigate proper setting parameters for the optimum dispensing ability. Materials and Methods 4types of liquids(water, serum, methanol, PEG 6000(25%)) and $TSH^{125}I$ tracer(515 kBq) are used to confirm pipetting ability. 29 specimens for Cyclosporine test are used to compare results. Prepare 8 plastic tubes for each of the liquids and with multi pipette $400{\mu}l$ of each liquid is dispensed to 8 tubes and $100{\mu}l$ of $TSH^{125}I$ tracer are dispensed to all of the tubes. From the prepared samples, $100{\mu}l$ of liquids are dispensed using a robotic liquid handing system, counted and calculated its CV(%) depending on types of liquids. And then by adjusting several setting parameters(air gap, dispense time, delay time) the change of the CV(%)are calcutated and finds optimum setting parameters. 29 specimens are tested with 3 methods. The first(A) is manual method and the second(B) is used robotic liquid handling system with existing parameters. The third(C) is used robotic liquid handling system with adjusted parameters. Pipetting ability depending on types of liquids is assessed with CV(%). On the basis of (A), patients's test results are compared (A)and(B), (A)and(C) and they are assessed with %RE(%Relative error) and %Diff(%Difference). Results The CV(%) of the CPM depending on liquid types were water 0.88, serum 0.95, methanol 10.22 and PEG 0.68. As expected dispensing of methanol using a liquid handling system was the problem and others were good. The methanol's dispensing were conducted by adjusting several setting parameters. When transport air gap 0 was adjusted to 2 and 5, CV(%) were 20.16, 12.54 and when system air gap 0 was adjusted to 2 and 5, CV(%) were 8.94, 1.36. When adjusted to system air gap 2, transport air gap 2 was 12.96 and adjusted to system air gap 5, Transport air gap 5 was 1.33. When dispense speed was adjusted 300 to 100, CV(%) was 13.32 and when dispense delay was adjusted 200 to 100 was 13.55. When compared (B) to (A), the result increased 99.44% and %RE was 93.59%. When compared (C-system air gap was adjusted 0 to 5) to (A), the result increased 6.75% and %RE was 5.10%. Conclusion Adjusting speed and delay time of aspiration and dispense was meaningless but changing system air gap was effective. By adjusting several parameters proper value was found and it affected the practical result of the experiment. To optimize the system active efforts are needed through the test and in case of dispensing new types of liquids proper test is required to check the liquid is suitable for using the equipment.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.962-969
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• 1999

Elastic and elasto-plastic stress analyses of AlN/Cu and AlN/W pints produced by active-metal brazing method using Ag-Cu-Ti insert-metal were performed with use of Finite-Element-Method(FEM). The results of stress analyses were compared with those from the pint strength tests and the observations of fracture behaviors. It was shown that a remarkably larger maximum principal stress is built in the AlN/Cu pint compared to the A1N/ W joint. Especially, the stress concentration with tensile component was confirmed at the free surface close to the bonded interface of AlN/Cu. The elasto-plastic analysis under consideration of stress relaxation effect of Ag-Cu-Ti insert possessing a so-called 'soft-metal effect' showed that the insert leads to a lowering of maximum principal stress in AlNiCu pint, even though an increase of the insert thickness above 100$\mu\textrm{m}$ could not bring its further decrease. The maximum pint strengths measured by shear test were 52 and 108 MPa for AlNiCu and AlN/W pints. respectively. Typical fractures of AlN/Cu pints occurred in a form of 'dome' which initiated from the free surface of AlN close to the bonded interface and proceeded towards the AlN inside forming a large angle. AlN/W pints were usually fractured at AlN side along the interface of AlN/insert-metal.

• Journal of Pharmacopuncture
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• v.12 no.4
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• pp.33-50
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• 2009

Objectives : This study was conducted to confirm validation and stability of concentration analysis method of pure melittin (Sweet Bee Venom-Sweet BV) extracted from the bee venom by utilizing protein isolation method of gel filtration. Methods : All experiments were conducted at Biotoxtech, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Standard solutions of melittin (SIGMA, USA) and test substances were dispensed and were analyzed with HPLC for Sweet BV to secure the validation of analysis. Results : 1. Measurement of system suitability of Sweet BV satisfied criterion of below 3%. 2. Confirming Linearity of Sweet BV in 10-200${\mu}g/m\ell$ solution yielded correlation coefficient (r) of 0.995 and accuracy of 85-115% which satisfy criterion. 3. Measurement of Specificity of Sweet BV didn't yield any substance affecting the peak of test substances, but detected at 21.22min verified as the test substance. 4. Confirming Intra-day of Sweet BV, accuracy and precision of 0.1, 100${\mu}g/m\ell$ were 105.70, 95.81 and 0.66, 0.73, respectively, satisfying both criteria of accuracy (85-115%) and precision (within 10%). 5. To measure Stability in autosampler, all samples used in Intra-day reproducibility sat in the autosampler for five hours and were re-analyzed. Both variability and precision satisfied the criteria. 6. Homogeneity of Sweet BV (0.1, 100${\mu}g/m\ell$) at upper, middle, and lower layers all satisfied the accuracy and precision criteria. 7. Stability of Sweet BV (0.1, 100${\mu}g/m\ell$) at room temperature for four hours and refrigerated for 7 days all satisfied the criterion. 8. For the measurement of Quality control, QC samples measured on the first and eighth day all satisfied accuracy and precision criteria. Conclusion : Above experiment data satisfies validation and stability of concentration analysis method of Sweet BV.