• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1195-1204
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• 2017

This study was designed to determine the effects of three cooking methods, boiling, microwave, and steaming, on elemental compositions of green pumpkin, zucchini, and sweet and ripened pumpkin. The cooking methods were carried out at 3, 5, and 10 min. The samples were then dried, crushed, and decomposed by microwave-assisted digestion method. Macro elements were analyzed by Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES), whereas ICP-Mass Spectrometer (ICP-MS) was used for micro elements determination. From the results, macro elements were present in the order of K, P, Ca, Mg, S, Fe, Zn, and Na in all analyzed pumpkins. Among micro elements, Mn, Cu, Rb, and Ba, were present at high levels. For the effects of cooking methods, boiling significantly reduced the concentrations of elements. Cooking time affected concentrations of elements in the same manner with large differences between elemental contents in samples cooked for 5 and 10 min. Regarding micro elements contents, both effects were not significant. Similar elemental compositions with different concentration levels in all pumpkin types were observed. Green pumpkin and ripened pumpkin showed high retention rates of inorganic components upon steaming, and zucchini and sweet pumpkin showed high retention rates upon microwave cooking. Conclusively, cooking method and time affect amounts of residual inorganic ingredients in pumpkin.

• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.359-367
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• 2016

Background: As new legislation has come into force implementing radiation safety management for the use of naturally occurring radioactive materials (NORM), it is necessary to establish a rapid and accurate measurement technique. Measurement of $^{238}U$ and $^{232}Th$ using conventional methods encounter the most significant difficulties for pretreatment (e.g., purification, speciation, and dilution/enrichment) or require time-consuming processes. Therefore, in this study, the applicability of ED-XRF as a non-destructive and rapid screening method was validated for raw materials and by-product samples. Materials and Methods: A series of experiments was conducted to test the applicability for rapid screening of XRF measurement to determine activity of $^{238}U$ and $^{232}Th$ based on certified reference materials (e.g., soil, rock, phosphorus rock, bauxite, zircon, and coal ash) and NORM samples commercially used in Korea. Statistical methods were used to compare the analytical results of ED-XRF to those of certified values of certified reference materials (CRM) and inductively coupled plasma mass spectrometry (ICP-MS). Results and Discussion: Results of the XRF measurement for $^{238}U$ and $^{232}Th$ showed under 20% relative error and standard deviation. The results of the U-test were statistically significant except for the case of U in coal fly ash samples. In addition, analytical results of $^{238}U$ and $^{232}Th$ in the raw material and by-product samples using XRF and the analytical results of those using ICP-MS ($R^2{\geq}0.95$) were consistent with each other. Thus, the analytical results rapidly derived using ED-XRF were fairly reliable. Conclusion: Based on the validation results, it can be concluded that the ED-XRF analysis may be applied to rapid screening of radioactivities ($^{238}U$ and $^{232}Th$) in NORM samples.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1272-1277
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• 2001

This study was designed to investigate the effects of Korean Gu-Gi-Ja tea on plasma hormone such as renin and aldosterone water in cadmium administered rats. The cadmium administered rats were given 50 ppm and 100 ppm of CdCl$_2$.2$H_2O$ disolved in the distilled water. Sixty male Sprague-Dawley rats weighing 100$\pm$10 g were divided into 6 groups according to body weight. The control group was fed standard diet without cadmium. The experimental groups, which were fed standard diet containing 50 ppm and 100 ppm cadmium and Gu-Gi-Ja tea group. The results of this study were as follows; food intake, body weight gain and kidney weight content in cadmium administered groups were lower than those in Gu-Gi-Ja tea group. The contents of cadmium in kidney of the rats were determined by using ICP (Inductively Coupled Plasma Spectrcphotometer). In kidney accumulation of Gu-Gi-Ja tea groups were lower than those in cadmium administered group. Plasma levels of renin activity was increased by Cadmium administration group, compared with Gu-Gi-Ja tea and cadmium administred group. Plasma levels of aldosterone activity was increased by cadmium administration group, compared with Gu-Gi-Ja tea and cadmium administred group. This results suggested that Gu-Gi-Ja tea has a lowering effects on the accumulation of cadmium in kidney and it is believed that the Gu-Gi-Ja tea has some protective effects to cadmium administered lenin and aldosterone hormone in rats, but the mechanism of these effects was obscure.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.477-480
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• 2002

Si-O-C(-H) thin film with a tow dielectric constant were deposited on a P-type Si(100) substrate by an inductively coupled plasma chemical vapor deposition (ICPCVD). Bis-trimethylsilymethane (BTMSM, H$_{9}$C$_3$-Si-CH$_2$-Si-C$_3$H$_{9}$) and oxygen gas were used as Precursor. Hybrid type Si-O-C(-H) thin films with organic material have been generated many voids after annealing. Consequently, the Si-O-C(-H) films can be made a low dielectric material by the effect of void. The surface characterization of Si-O-C(-H) thin films were performed by SEM(scanning electron microscope). The characteristic analysis of Si-O-C(-H) thin films were performed by X-ray photoelectron spectroscopy (XPS).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.169-169
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• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.372-381
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• 2015

The effect of preparation method on the catalytic activities of the $Ni/Al_2O_3$ catalysts on steam reforming of ethylene glycol was investigated. The catalysts were prepared with various preparation methods such as an incipient wetness impregnation, wet impregnation, and coprecipitation method. In the case of coprecipitation method, various precipitants such as KOH, $K_2CO_3$, and $NH_4OH$ were compared. The prepared catalysts were characterized by using $N_2$ physisorption, inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction, temperatureprogrammed reduction, pulsed $H_2$ chemisorption, temperature-programmed oxidation, scanning electron microscopy, and thermogravimetric analysis. Among the catalysts reduced at 773 K, the $Ni/Al_2O_3$ catalyst prepared by a coprecipitation with KOH or $K_2CO_3$ as precipitants showed the best catalytic performance. The preparation method affected the particle size of Ni, reducibility of nickel oxides, catalytic performance (activity and stability), and types of coke formed during the reaction. The $Ni/Al_2O_3$ catalyst prepared by a coprecipitation with KOH showed the increasing catalytic activity with an increase in the reduction temperature from 773 to 1173 K because of an increase in the reduction degree of Ni oxide species even though the particle size of Ni increased with increasing reduction temperature.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.435-441
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• 2012

The direct conversion of cellulose into polyols in $H_2$ was examined over Pt catalysts supported on various zeolites, viz., mordenite, Y, ferrierite, and ${\beta}$. For comparison, Pt catalysts supported on ${\gamma}-Al_2O_3$, $SiO_2-Al_2O_3$, and $SiO_2$ were also tested. The physical properties of the catalysts were probed with $N_2$ physisorption. The surface acidity was measured with temperature programmed desorption of ammonia ($NH_3$-TPD). The Pt content was quantified with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The Pt dispersion was determined with CO chemisorptions and transmission electron microscopy (TEM). The conversion of cellulose appeared to be mainly dependent on the reaction temperature and reaction time because it depends on the concentration of $H^+$ ions reversibly formed in hot water. Pt/H-mordenite (20) showed the highest yield to polyols among the tested catalysts. Pt/H-zeolite was superior to Pt/Na-zeolite for this reaction. The polyol yield was dependent on the surface acid density and the external surface area.

• The Journal of the Petrological Society of Korea
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• v.24 no.2
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• pp.141-147
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• 2015

Using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), we evaluated the reliability of trace element abundance data measured from the silicate rock references of JR-3, JG-3, JGb-1 and JB-1b using glass discs made by alkali fusion. For 28 elements including rare earth elements, relative standard deviations (RSD) are better than 7% in case when the concentrations of the elements in the rock samples are greater than 10 ppm. However, RSD shows somewhat increased values for the concentrations less than 10 ppm, but never exceeds 25%. Compared with previously reported averages of the compiled abundance data, our data display satisfactory results for the most cases with differences less than 10%. We suggest that LA-ICP-MS analysis using fused glass beads is a reliable, precise and time-saving method of trace element analysis for the silicate rocks spanning from mafic to felsic compositions.

• The korean journal of orthodontics
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• v.35 no.2 s.109
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• pp.127-136
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• 2005

The purpose of this study was to examine the cytotoxicity of orthodontic wire which had an increased diameter through electroplating, and to evaluate its possible clinical applications, First. nickel plating was carried out on the commercially available stainless steel wire using an electroplating technique For the comparison of the electroplated wire with ready made stainless steel wire and titanium or copper. each wire was incubated for 72 hours in a medium. The release of the metal ion was measured using ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrophotometer). Balb/c 3T3 mouse fibroblast was put on a microplate and placed in an incubated medium of 75%, 50%, and 20% dilation. An MTT analysis was used to compare with the medium only. The change in absorbency value of each wire group and the difference of absorbency value according to the change of dilution was measured The results of ICP-AES analysis showed that great amount nickel iou was isolated from electroplated orthodontic wires and great amount copper ion was isolated from copper. The results of the MTT analysis showed that there was no difference in the absorbency value of titanium at any dilution. However, the electroplated wires (p<0.001) the stainless steel wires (p<0.05) and the copper (P<0.001) were statistically significantly lower than those of medium only at all dilutions. Assessment as per ISO 10993, part 5, showed that electroplated wire was alloted to 'moderate cytotoxic' the titanium and stainless steel wire were 'non-cytotoxic' The results of this study indicate that the electroplated orthodontic wires need additional efforts to decrease cytotoxicity for their clinical applications.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.172-177
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• 2015

PURPOSE. The purpose of this study was to evaluate cell toxicity due to ion release caused by galvanic corrosion as a result of contact between base metal and titanium. MATERIALS AND METHODS. It was hypothesized that Nickel (Ni)-Chromium (Cr) alloys with different compositions possess different corrosion resistances when contacted with titanium abutment, and therefore in this study, specimens ($10{\times}10{\times}1.5mm$) were fabricated using commercial pure titanium and 3 different types of Ni-Cr alloys (T3, Tilite, Bella bond plus) commonly used for metal ceramic restorations. The specimens were divided into 6 groups according to the composition of Ni-Cr alloy and contact with titanium. The experimental groups were in direct contact with titanium and the control groups were not. After the samples were immersed in the culture medium - Dulbecco's modified Eagle's medium[DMEM] for 48 hours, the released metal ions were detected using inductively coupled plasma mass spectrometer (ICP-MS) and analyzed by the Kruskal-Wallis and Mann-Whitney test (P<.05). Mouse L-929 fibroblast cells were used for cell toxicity evaluation. The cell toxicity of specimens was measured by the 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyltetrazolium bromide (MTT) test. Results of MTT assay were statistically analyzed by the two-way ANOVA test (P<.05). Post-hoc multiple comparisons were conducted using Tukey's tests. RESULTS. The amount of metal ions released by galvanic corrosion due to contact between the base metal alloy and titanium was increased in all of the specimens. In the cytotoxicity test, the two-way ANOVA showed a significant effect of the alloy type and galvanic corrosion for cytotoxicity (P<.001). The relative cell growth rate (RGR) was decreased further on the groups in contact with titanium (P<.05). CONCLUSION. The release of metal ions was increased by galvanic corrosion due to contact between base metal and titanium, and it can cause adverse effects on the tissue around the implant by inducing cytotoxicity.