• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.11a
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• pp.43-49
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• 2002

A7003 alloy has characteristics of their excellent weldability, high corrosion resistance and superior plastic working however the broadening of application for the alloy has been hampered by the lower extrudability associated by Mg content. For improvement of extrudability and enhanced recovery efficiency during Al scrap recyeling, it has been generally practiced to reduce Mg content in A7003 alloy. Therefore, it is necessary to investigate the influence of Mg content on mechanical strength and extrudability of A7003 alloy. For efficient material processing which has small amounts, life cycle assessment in material processing(MLCA) is evaluated. The quantitative analysis of energy requirements and $CO_2$ emission for production of A7003 extruded bar are estimated with different Mg content and billet pre-heating process (heating source by light oil or LPG). In particular, the estimation of energy requirements was performed within shipping and gating range (except the mining and extraction stages)to investigate the influence of the variables on energy requirements and $CO_2$ emission in detail. As Mg content increased, the flow stress and the extrusion pressure for A7003 alloy increased. It has been thought that an increment in extrusion pressure with increasing Mg content is caused by the solid solution hardening of Mg atoms in the matrix and increment in volume fraction of intermetallic compound, $Mg_2Si$. The extrudability and the tensile strength are equal to, or above that of conventional A 7003 alloy even the content of Mg varied from $1.1wt.\%\;to\;0.5wt.\%$ alloy. This means that minimizing the content of Mg in A7003 alloy can enhance recovery efficiency during Al scrap recycling. It can be quoted that rather than Mg content energy source for billet heating is a prime factor to determine the atmospheric $CO_2$ emission.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.3
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• pp.113-119
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• 2011

This study was designed to determine the effects of larval extracts from Protaetia brevitarsis seulensis shade dried larva from Korea and China on liver tissues of hepatic injury groups. The experimental groups are divided into five groups; Normal, carbon tetrachloride single injection ($CCl_4$), Pb-CHI ($CCl_4$ + P. brevitarsis shade dried larva from China), Pb-KOR ($CCl_4$ + P. brevitarsis shade dried larva from Korea) and SIL ($CCl_4$ + 0.35% silymarin) groups. Sprague Dawley rats were oral injected with $CCl_4$ at a dose l mg/kg (20% in corn oil) for induction of liver damage for 4 weeks. Each experimental group was fed with a dose 50 mg/kg of larval extracts based on medicinal preparations from 3 weeks to 4 weeks after $CCl_4$ treatment. At the end of 4 weeks, we evaluated the serum levels of glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transferase (GPT), alkaline phosphatase (ALP) and blood urea nitrogen (BUN) in serum and the cytokine levels of tumor necrosis factor-${\alpha}$) (TNF-${\alpha}$) and transforming growth factor-${\beta}$ (TGF-${\beta}$) in the cells isolated from spleen and liver. The histological analysis was also conducted. The $CCl_4$ injection reduced body weight, induced congestion of middle lobe and hepatocytic degeneration, resulting in disintegration of hepatic cords, and increased biochemical markers of blood related to hepatic injury. On the other hand, the Pb-CHI and Pb-KOR group decreased the levels of biochemical markers in blood and cytokine levels in spleen and liver. Especially, the Pb-KOR group facilitated the recovery of biochemical values of blood related to hepatic injury, hepatic lesions and fibrosis. Taken together, larval extract from P. brevitarsis might prevent acute hepatotoxicity and enhance the recovery of liver fibrosis and cirrhosis induced by $CCl_4$, and the ingredients could be a promising candidate for the prevention and treatment of hepatic disorders.

• Structural Engineering and Mechanics
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• v.59 no.1
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• pp.37-57
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• 2016

Reservoir geomechanics can play an important role in hydrocarbon recovery mechanism. In $CO_2$-EOR process, reservoir geomechanics analysis is concerned with the simultaneous study of fluid flow and the mechanical response of the reservoir under $CO_2$ injection. Accurate prediction of geomechanical effects during $CO_2$ injection will assist in modeling the Carbon dioxide recovery process and making a better design of process and production equipment. This paper deals with the implementation of a program (FORTRAN 90 interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators, using a partial coupling algorithm. A geomechanics reservoir partially coupled approach is presented that allows to iteratively take the impact of geomechanics into account in the fluid flow calculations and therefore performs a better prediction of the process. The proposed approach is illustrated on a realistic field case. The reservoir geomechanics coupled models show that in the case of lower maximum bottom hole injection pressure, the cumulative oil production is more than other scenarios. Moreover at the high injection pressures, the production rates will not change with the injection bottom hole pressure variations. Also the FEM analysis of the reservoir showed that at $CO_2$ injection pressure of 11000 Psi the plastic strain has been occurred in the some parts of the reservoir and the related stress path show a critical behavior.

• Journal of Korean Society for Quality Management
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• v.47 no.2
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• pp.345-365
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• 2019

Purpose: We consider export of Korea for Muslim population of Cairo residents in Egypt. Product instant cup noodle and yuzu tea are mainly focused on Kano model and Timko's customer satisfaction factor (CS - Coefficient) analysis and conjoint analysis. Methods: Based on the evaluation and conjoint analysis, cluster analysis was additionally applied to further exploratory research as to what kind of population the target customer has. A total of 120 people, each 60 people each, were prosecuted for Muslim women, middle middle class who had over 3,000 Korean won annual income for that study, and in Cairo in August 18. Results: The Kano analysis result Instant cup noodles act as attractive elements for packaging state, cooking method, smell and convenience, and Yuzu tea acted as an attractive element of taste, eating method, raw materials, efficacy, packaging form. Customer satisfaction factor, instant cup noodles, capacity and noodle thickness was a factor of indifference in Kano analysis, but acted as an attractive factor, the way to eat citron tea was classified as a factor of indifference. Conclusion: In the case of instant cup noodles, we first set up the taste of chicken-based soup with high appreciation as a whole, a group that likes chicken-based soup taste and oil noodles for each market segment, a taste of beef based soup And popular group that likes raw noodles Appears that diversification is necessary, and it has been found that it is necessary to develop a product type by hierarchy and marketing with different size priority from group packaging container. In the case of Yuzu tea, it is indispensable to emphasize the efficacy, in particular, energy recovery preference appears high, appealing point matching the needs of energy recovery is necessary, release the citrus fruit as a product without buckwheat in Bisson Ho, the packaging container, The group that likes cups and sticks is different and we found that it is necessary to prepare all two types.

• Geomechanics and Engineering
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• v.18 no.2
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• pp.205-213
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• 2019

A calculation model of reservoir pressure field distribution around multiple production wells in a heavy oil reservoir is established, which can overcome the unreasonable uniform-pressure value calculated by the traditional mathematical model in the multiwell mining areas. A calculating program is developed based on the deduced equations by using Visual Basic computer language. Based on the proposed mathematical model, the effects of drainage rate and formation permeability on the distribution of reservoir pressure are studied. Results show that the reservoir pressure drops most at the wellbore. The farther the distance away from the borehole, the sparser the isobaric lines distribute. Increasing drainage rate results in decreasing reservoir pressure and bottom-hole pressure, especially the latter. The permeability has a significant effect on bottom hole pressure. The study provides a reference basis for studying the dynamic pressure field distribution before thermal recovery technology in heavy oilfield and optimizing construction parameters.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.587-599
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• 2018

The coffee grounds generated during the coffee extraction process contain several resources, but the technology for their recycling has not been commercialized yet, causing various environmental problems. Due to the recent increase in coffee consumption worldwide, the amount of coffee grounds produced has been continuously increasing, reaching more than 750 million tons. In Korea, about 120,000 tons of coffee waste are annually generated; however, most of them are landfilled or incinerated. Although there is still a shortage of coffee waste recycling technologies compared to the amount of coffee grounds produced, various recycling approaches are being actuated in many countries including Korea. In this study, the generation of coffee grounds at home and abroad, the status of coffee grounds recycling, and the associated technology development trends were investigated. The coffee grounds recycling has been studied in the fields of energy, adsorbent, construction, agriculture, and bio-foods. Research is most active in the energy and biotechnology areas; in particular, since the oil in the coffee grounds is valuable as a feedstock for biomass energy, the technology related to energy recovery is currently under development worldwide. Removed because confusing and unnecessary.

• Analytical Science and Technology
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• v.33 no.1
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• pp.11-22
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• 2020

When extracting semi-volatile components of herbal medicines using hot water vapor, some substances may react with water vapor or oxygen, and some volatile substances may be lost, when using an organic solvent extraction method has the disadvantage that it may contain a non-volatile material and residual organic solvent. In addition, it is inefficient to separate semi-volatile substances from herbal medicines into each single component and conduct biological activity research for each component to determine the effective ingredient, and some components may be lost in the separation process. In this study, semi-volatile substances evaporated under two pressure-reduced conditions in Chinese herbal medicines such as Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were separated by cooling with liquid nitrogen. Those were analyzed by gas chromatography-mass spectrometry (GC-MS) to identify the components, and this method may be used to study biological activities at the cellular level. The substances separated under reduced pressure, essential oil obtained by simultaneous distillation extraction (SDE) method and substances by using solid phase micro-extraction (SPME) from Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were analyzed by GC-MS. In the case of Cnidii Rhizoma and Aucklandiae Radix, there were some differences among the essential oil components obtained by SDE and those identified by low temperature capture (CT) and SPME method, these were believed to be produced by some volatiles reacting with water or oxygen at the boiling point temperature of water.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.383-391
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• 2017

This study examines the relationship between sentiment of speculators and price movements in the futures markets of WTI crude oil, copper, and wheat during the period 2003~2014 using Granger causality tests. The results indicate that speculative positions overall has no predictive power for returns in each futures market. Rather, returns seem to have effects on speculators' sentiment especially during periods of both economic expansion and recovery. During a recession, meanwhile, changes of speculators' sentiment index in the WTI crude oil and copper markets provide predictive power for returns in a positive direction, suggesting that speculators' pessimistic sentiment aggravates declines in commodity prices. Since the effects of speculative positions on market prices are ambiguous, tight regulations on speculative trading are not advisable. In a bearish market, however, regulatory bodies should consider raising speculative position limits because large speculative short positions and (or) liquidation of index traders' long positions may lead steep price declines.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.52-60
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• 2004

The basic approach to sewage sludge is organic waste minimization, promotion of energy recovery; volume and weight reduction by final treatment, and environmentally final disposal of natural circulation. Dry and pyrolysis of maize was experimentally investigated in full-scale rotary kiln in semi-continuous operation. The operational parameters varied are the operating temperature $160{\sim}175^{\circ}C$ of dry and $450{\sim}800^{\circ}C$ of pyrolysis, the solids residence time 9 min for pyrolysis. Important parameters studied include the running time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas production components was observed. The gas of $C_1{\sim}C_3$ yield increased and oil of $C_4{\sim}C_6$ yield decreased along with pyrolysis temperature of $670^{\circ}C$ by the run time of 9 min.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.520-525
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• 1990

A modified method of urea adduct formation, in which water and organic solvent were used as the wetting agent and the reaction medium. respectively, is suggested to obviate methanolysis and to ease recovery in the separation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. With the new method the fraction in which the total content of EPA. DHA and their precursors is more than 80% could be obtained. Although the total content of precursors in the concentrate was hardly affected by the kind of the wetting agent or the organic solvent, the content of EPA and DHA varied significantly depending on the organic solvent. This finding made it possible to selectively enrich the desired components. After DHA-enriched fraction (I)HA is 50%) was obtained by using pentane, EPA-enriched fraction ( EPA is 53%)) could be obtained from the residue of DHA-enriched fraction by using heptane.