• Polymer(Korea)
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• v.38 no.2
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• pp.193-198
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• 2014

Lens and DVD require high quality of optical property. Conventional injection molded products contain high residual stress and this invokes birefringence since high cavity pressure and high temperature variation are involved in a molding process. Thus these products are often molded by injection compression molding in order to minimize the residual stress through reducing cavity pressure and uniform cavity pressure. In this study, molding parameters affecting molding quality such as property uniformity in injection compression molding were investigated through experiment. Molding quality deviations among the cavities in multi-cavity mold were also studied. Transparent resins, PC and PS were used in this study. Compression gap, compression speed, compression force, and compression delay time for processing variables in injection compression molding were applied in experiment. Compression force, compression delay time, and compression gap significantly affected the optical property of product. The degree of influence of process variable on the product quality was different in different resins. This implies that the optimal operational conditions in injection compression molding existed for each resin according to flow property.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.2
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• pp.97-105
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• 2014

In the case of the direct measurement of $^{226}Ra$ using a HPGe gamma-ray spectrometer, the interference between gammarays with 186.21 keV of $^{226}Ra$ and 185.7 keV of $^{235}U$ should be corrected to calculate the net peak area in the energy spectrum. In general, it is very difficult to conduct peaks stripping with difference of about 0.5 keV, although a HPGe with the superior resolution is applied and the maximum channels is applied to the spectrometer. In this study, several interference correction techniques in the direct measurement were surveyed to evaluate the feasibility for the measurement of $^{226}Ra$ using the gamma-ray spectrometery. Applying the interference corrections to the analysis of raw materials and by-products, the method validation for the direct measurement of $^{226}Ra$ was conducted by evaluating the measurement uncertainty, linearity, and range. As a result, the optimum method of the interference correction was selected by comparing with the indirect measurement of which progenies of $^{226}Ra$, such as $^{214}Pb$ and $^{214}Bi$, were analyzed in the secular equilibrium state.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.108-123
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• 2018

This paper focuses on the relationship between center and periphery by discussing the circulation of rare resources, such as bronze, stamped hard pottery, and proto-porcelain. The discussion includes two parts: the internal Shang culture region and the region outside of Shang. Within the Shang culture region, all the resources mentioned above were brought from different places to the Panlongcheng site and then transferred to Zhengzhou Shang city. On the other hand, they also produced and consumed the resources in a special way, which indicates a certain degree of independence. Outside the Shang region, bronze products and maybe even raw copper resources were circulated from Zhengzhou Shang city to the Chengyang site, while stamped hard pottery and proto-porcelain were transferred to Zhengzhou through the Panlongcheng site. Resource circulation was bi-directional. Thus, this resource circulation was one of the key factors to building the relationship between center and periphery.

• Korean Journal of Environmental Agriculture
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• v.38 no.1
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• pp.61-67
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• 2019

BACKGROUND: Many studies on artificial lighting have been recently performed to investigate its effect on agricultural products with good quality. This review was aimed at comparing the effects of artificial light on functional metabolites of the plants that were grown in greenhouses and growth chamber. METHODS AND RESULTS: It has been summarized that artificial lighting both in growth chambers and greenhouses caused different functional metabolites patterns depending on light quality. Even though the same light quality was applied, different patterns in metabolites were observed in different plant species. For the same species, supplementation of the same light quality in both growth chambers and greenhouses did cause different functional metabolites patterns. CONCLUSION: Artificial lighting caused different patterns in functional metabolites of plants grown in greenhouses and growth chambers, depending on the light quality and/or plant species. The manipulation of plant growth and functional metabolites would be possible by engineering the light qualities, but knowledge on proper lighting condition depending on plant species and growth places would be necessary.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.299-303
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• 2007

The objective of this study was the development of immunochromatography (ICG) for the rapid and accurate detection of Listeria monocytogenes. Here, monoclonal antibodies (MAb) were conjugated with 40 nm colloidal gold particles, where the conjugate was used as the detection reagent in the ICG. The ICG was composed of three pads (sample, conjugate, and absorbance pads) and one nitrocellulose membrane. The colloidal gold-MAb conjugate was applied to the conjugate pad, and the test line and control line on the membrane were treated with MAb (FKLM-3BI2-37) and anti-mouse IgG, respectively. The detection limit of the ICG was $10^{5}$ cell/mL and it showed no cross-reaction to food borne pathogens. We inoculated meat and lettuce samples with various counts of L. monocytogenes, and analyzed them by ICG. All the inoculated meat samples gave positive results after enrichment for 24 h in LEB. These results indicate that ICG was able to serve as a primary screening tool for L. monocytogenes in various foods and agricultural products within 20 min after enrichment.

• Food Science and Preservation
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• v.22 no.3
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• pp.421-427
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• 2015

Oriental melon (Cucumis melo L. var. makuwa) has been widely consumed as various processed foods, such as dried products, jelly, wine, juice, and vinegar, in Asian countries. In fruit processing, blanching and pressure treatments affect its quality, such as antioxidant activities, sensory characteristics, and etc. This study was conducted to evaluate the effects of blanching and pressure pre-treatments on oriental melon wine-making (BP, blanching and pressure filtration; BNP, blanching and non-pressure filtration; NBP, non-blanching and pressure filtration; and NBNP, non-blanching and non-pressure filtration). Physicochemical properties and antioxidant capacities by ${\alpha}$, ${\alpha}$-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing antioxidant power (FRAP) assay, and total phenolic and total flavonoid contents were measured for comparison of the different pre-treatment methods. After the aging process, the alcohol contents and pH values showed no statistical differences, whereas the amount of soluble solids, reducing sugar, and titratable acidity were slightly different among the pre-treatments (p<0.05). The samples with blanching pre-treatment showed higher antioxidant capacities than those of other pre-treatments. In the sensory evaluation, the BNP was the best in overall acceptability. Thus, this study showed that the blanching treatment enhanced the antioxidant capacities and sensory qualities of the oriental melon wine.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.269-276
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• 2019

A colorimetric rapid detection method based on acetylcholinesterase (AChE) was developed for the analysis of organophosphorus (OP) and carbamate (CB) pesticides. The AChE catalyzes acetylthiocholine into thiocholine having (-) and (+) charges, and the (+) charge results in gold nanoparticle (GNP) aggregation. The in-activation of AChE by OP and CB has been well known. In order to optimize the colorimetric method, optimal dilution times of commercial serum containing AChE, diameter of GNP, and concentration of acetylthiocholine were tested as a key parameter. The colorimetric detection limits of the method were 7.5 ng/mL for both dimethyl amine and carbofuran pesticides in 60% ethanol. No cross-reaction to other chemicals, such as aflatoxin B1 and ochratoxin A, which can be contaminated with pesticides in agricultural products, was observed. Recoveries from lettuce, sesame leaf, and cabbage lettuce spiked with known concentrations of dimethyl amine and carbofuran were found to be ranged from 83.85 to 133.16%. These results indicated that the colorimetric rapid method based on AChE can be a useful tool for the sensitive, specific, rapid, and accurate detection of OP and CB pesticides in fresh vegetables.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.1-8
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• 2021

The inverted Y-shaped strip detection method based on acetylcholinesterase (AChE) was developed for the rapid detection of organophosphorus and carbamate pesticides. The inactivation of AChE by organophosphorus and carbamate pesticides has been well known. The AChE catalyzes acetylthiocholine into thiocholine having (-) and (+) charges, and the (+) charge results in aggregation of gold nanoparticle (GNP). Malaoxon and carbofuran were used as standard organophosphorus and carbamate for the development of the inverted Y-shaped strip, respectively. In order to optimize the method, various angles of the Y-shaped strip, different types of nitrocellulose membrane, and concentration of AChE were tested as key parameters. The detection limit of the method was 10 ng/mL for both malaoxon and carbofuran pesticides. No cross-reaction was observed to other pesticides such as atrazine, cyanazine, simazine, bifenthrin, boscalid, metalaxyl, and chlorobenzilate. Recoveries from lettuce spiked when known concentrations of malaoxon and carbofuran were found ranging from 96.4 to 100.7% and 81 to 112.7%, respectively. This study suggests that the inverted Y-shaped strip method based on AChE may be a useful tool for the sensitive, specific, rapid detection of organophosphorus and carbamate pesticides in agricultural products.

• Journal of the Korean association of regional geographers
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• v.15 no.6
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• pp.720-735
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• 2009

This paper studies the characteristics of the restructuring of chemical industrial complex in JiLin city since 1978 focusing on enterprise organization, the process of production, labor, and consumer market. The number of chemical industrial enterprises and their partnership with subcontractors have increased since 2001. As for the type of cooperation group, research institutes and local government are accounted for the greatest portion. The chemical industrial enterprise in JiLin which has adopted Fordism production method still has the highest percentage in 2007. And in the shift process of production system after China's entry into WTO(in 2001), chemical industrial enterprise in JiLin city takes allowing more investment in production technologies as core strategy, while taking improvement in equipment and development of new products as core strategy in the shift process of production technology. The degree of labor re-education was highest in 2007, and as for the relationship between labor and management, enterprises which evaluate the ability of performance of duty are increasing. The characteristics of restructuring of chemical industrial complex on consumer market, domestic market accounted for the greatest portion, on the other side the export is feeble. As for strategy of market restructuring, industrial enterprise in JiLin city should use Quality improvement and high-value added as core strategies to cope with alteration of market.

• Journal of Conservation Science
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• v.30 no.3
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• pp.263-275
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• 2014

It's shown how to proceed the study on Manufacturing techniques & Conservation to the Iron Pot from Cheonmachong Ancient Tomb(the 155th Tomb in Hwangnam-dong). In order to investigate manufacturing techniques of the Iron Pot, some parts of the relic were gathered. After mounting, polishing and etching on the relic, analyzing the metal microstructure was conducted. Also it's conducted a SEM-EDS analysis on the nonmetallic inclusion. White iron structure was observed in the metallurgical structure inspection, SEM-EDS analysis. It seems to be dried slowly at room temperature after casting, doesn't look as particular heat treatment to improve brittleness. It is estimated that it's as the handle seam side were verified about 3cm inch wide, 1.5 thick in center of body, so 2 separate half-completed products was cast with width-type mould. The manufacturing techniques Using white cast iron structure, width-type mould are observable to the Iron Pot excavated from Sikrichong Ancient Tomb & Hwangnamdaechong grand Ancient Tomb around those were constructed the same time. It's able to recognize that it's almost identical manufacturing techniques at that time. Conservation is generically following those are survey of pretreatment, foreign material removal, stabilization, restoration and color matching in the order. cleaning & drying were added to the process as occasion demands. The strengthening treatment were difficult with artifact's volume, low concentration Paraloid NAD-10 solution was spread two or three times with a brush, surface hardening also came up with 15wt% Paraloid NAD-10 solution after the conservation was complete. There were connection & restoration for the restoration to the damage after modeling forms that it's similar to damaged parts by using the Fiber Reinforced Plastic resins(POLYCOAT FH-245, mold laminated type). Throughout this research, capitalizing on accumulations of measurements about the production technique of Iron Pot in the time of the fifth and 6th centuries is no less important than the Iron artifact's conservation for a better study in the future.