• Journal of the Korean Electrochemical Society
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• v.25 no.1
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• pp.42-49
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• 2022

In this study, the surface protection film based on organic-inorganic composite is manufactured for suppressing lithium dendrite growth, and the film is applied on the surface of Li metal negative electrode for lithium metal batteries (LMBs). The film is consist of the polyvinylidene fluoride (PVDF) polymeric binder which has good mechanical strength and high electrochemical stability, and carbon black (Super-P) which has outstanding electrical conductivity as the inorganic compound. First, in order to confirm the suppression of the internal short circuit by the lithium dendrite, the time required for the short circuit is measured while a constant current is continuously applied. As a result, the internal short circuit is delayed in proportion to the carbon black content of the film, and it is significantly delayed than bare Li metal electrode which does not use protection film. The cycle performance of the thick protection film (8 ㎛), is worse than that of the thin film (4 ㎛). However, as the carbon black content of the film increased, the cycle performance is improved. Thus, the surface protection film based on carbon black/PVDF composite can delay the internal short circuit, and has low overvoltage during the cycle. However, more stable cycle performance needs to be built through further improvements.

• Korean Journal of Plant Resources
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• v.35 no.4
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• pp.455-463
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• 2022

The effects of freeze-drying (FD), room-temperature drying (RD), and room-temperature drying after roasting (RDAR) on the volatile organic compounds (VOCs), sugar content, flavonoids, and antioxidant activity of Hallabong peel tea were tested. This experiment was conducted to collect a basic information for developing of peel tea. FD samples showed lower total soluble solids and VOCs than other drying treatments. RDAR samples showed a significant difference in VOCs and visual color of FD samples. The reduced VOCs in FD samples was caused by freeze drying treatment; identical VOCs composition of hallabong peel was detected from condensed ice of freeze-drying machine. Metabolomics analysis showed no difference among three drying treatments. In addition, antioxidant activity and total phenolic compounds were not significantly different from three different drying treatments. Thus, RD or RDAR is a suitable drying method for hallabong peel tea rather than FD method in terms of VOCs and economical reasons.

• Journal of Practical Agriculture & Fisheries Research
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• v.5 no.1
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• pp.28-35
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• 2003

This study was conducted to investigate the nutrition status, growth and fruit quality of 'Campbell Early' grapes in Hwaseong area. Organic matter content of 3 vineyard soils was significantly lower than standard value. P₂O₅ and K contents of Y vineyard and P₂O₅ of C vineyard were very high. But there were no significant differences in contents of Ca, Mg and CEC. Compared to the standard value. T-N, Ca and Mg contents of petiole were adequate. P₂O₅ contents of Y and C vineyard and K contents of Y vineyard were significantly higher than standard value. Berry firmness, color and bloom occurrence on fruit skin showed no differences among 3 vineyard. Soluble solids content poorly, yield per tree and goods fruit of C vineyard decreased significantly compared to the fruit in Y and H vineyards. Russetted fruit of Y vineyard, colored fruit of H vineyard, and unfertilized fruit, cracked fruit, and bitter rot were observed frequently.

• Composites Research
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• v.36 no.5
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• pp.297-302
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• 2023

There are several methods for shaping foams, but the most commonly used methods involve the use of resin mixed with a foaming agent, which is then foamed under high temperature and pressure in the case of compression foaming, or foamed under high temperature without applying pressure in the case of atmospheric foaming. The polymers used for foaming require design and analysis of optimal foaming conditions in order to achieve foaming under ambient pressure. Environmentally friendly bio-based polymers face challenges when it comes to foaming on their own, which has led to ongoing research in blending them with resins capable of traditional foam production. This study investigates changes in the characteristics of bio-based polymer-EVA blend foams based on variations in the content of bio-based polymers and explores the optimal foaming conditions according to crosslinking. The correlation between foaming characteristics and mechanical properties of the foams was examined. Through this research, we gained insights into how the content of bio-based polymers affects the properties of foams containing bio-based polymers and identified differences between ambient pressure and high-pressure foaming processes. Additionally, the feasibility of commercializing bio-based polymer-EVA composite foams was confirmed.

• Journal of the korean society of oceanography
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• v.32 no.2
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• pp.85-92
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• 1997

Seasonality in abundance and egg production was investigated for Calanus sinicus in Asan Bay, Korea, and feeding effort was measured in the laboratory condition. Although abundances of this species in this bay showed only one Peak in spring, egg Production showed two peaks, spring and fall, in this bay. Potential of year-round egg Production was also found. Food availability judged by the particulate organic carbon (POC) concentration was usually more than enough in this bay. High egg Production in fall resulted in spring Peak in abundance. But high egg Production in spring did not result in summer or fall Peak in abundance. Low abundances in summer and fall were believed to be the result of long range horizontal migration out to the central Part of the Yellow Sea. The highest average egg Production by the Population of this species was 16.3 eggs female-'day-'. Maximum e99 Production by an individual was 39.0 e99s female$^{-1}$ day$^{-1}$, which yielded 30.7% of specific egg Production rate in terms of body carbon content with the carbon contents of 44.44$^{\mu}$gC and 0.35 $^{\mu}$gC for individual adult female and egg, respectively. Clearance rate (F) measured in the laboratory condition decreased exponentially with the increase of food concentrations, as expected. The asymptote of F was 3.17 ml copepod$^{-1}$ h$^{-1}$. When this value and the minimum concentration of POC measured in the field were applied under the assumption of continuous feeding in the nature, the calculated gross efficient of egg production was 41.6% in case of average egg production of the population. Violation of the assumption of diurnal feeding rhythm and application of the minimum concentration of POC may offset the influence on calculation each other.

• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.123-128
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• 1993

The polyesters (polyhydroxyalkanoates; PHAs) production capability in a two-step cultivation of Alcaligenes eutrophus H16(ATCC 17699) was investigated by using various organic carbon sources. The carbon sources used included linear $C_2~C_10$ monocarboxylic acids, $C_3~C_10$ dicarboxylic acids, crotonic acid, and several linear vicinal and $\omega$-diols. The polyesters synthesized were characterized by 500 MHz $^1 H-NMR$ spectroscopy, intrinsic viscosity$[\eta]$ measurement in chloroform and differential scanning calorimetry (DSC). The PHAs synthesis data showed that the use of C-odd ($C_3, C_5, and C_7$) monocarboxylic acids resulted in poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(P(3HB-co-3HV) (3HV content ranging 40 to 70 mol%) while the use of $C_9$ substrate gave the copolyester containing only 4 mol% of 3HV. All culture products obtained on $C_3$~C$_{10}$ dicarboxylic acids gave exclusively P(3HB). 500 MHz $^1 H-NMR$ analysis showed that all polyesters synthesized generally contained 1~2 mol% 3HV even for the unrelated substrates such as the carboxylic acids with even number of carbon. When $\alpha, \omega$-diols with even number of carbon were used as substrates, 4-hydroxybutyrate(4HB) was inserted into the polyester chain composed of P(3HB-co-4HB). Vicinal diols were generally not utilized by the bacterium for polyester production.n.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.12
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• pp.1661-1666
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• 2009

The objective of this study was to determine the effect of Se-enriched bean sprout, Se-enriched yeast and sodium selenite on productivity, egg quality and egg Se concentrations in laying hens. Using a Completely Randomized Design, 144 Rohman laying hens at 71 weeks of age were divided into four groups. Each group consisted of four replicates and each replicate contained nine hens. The dietary treatments were T1: control diet, T2: control diet plus 0.3 mg Se/kg from sodium selenite, T3: control diet plus 0.3 mg Se/kg from Se-enriched yeast, T4: control diet plus 0.3 mg Se/kg from Se-enriched bean sprout. The results showed that there was no significant difference (p>0.05) in feed intake, egg production and egg quality among treatments. Selenium supplementation from Seenriched yeast and Se-enriched bean sprout markedly increased (p<0.05) egg Se concentration as compared to the control and sodium selenite groups. The results indicated that Se-enriched bean sprout could be used as an alternative Se source in diets of laying hens.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.735-741
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• 2008

In our previous study, a surfactant-coated Candida rugosa lipase immobilized in microemulsion-based organogels was exploited for the synthesis of ethyl isovalerate. In the present study, we are focusing on the effective reuse of lipase immobilized in microemulsion-based organogels (MBGs) in terms of retainment of the catalytic activity. As water is one of the co-products in esterification reactions, the removal of water becomes a priority to allow the reaction to work in the forward direction and to prevent back hydrolysis. Taking this fact into consideration, the lipase-containing microemulsion-based organogels were given pretreatment and/or several intermittent treatments with dry reverse micellar solution of AOT in organic solvent during repeated cycles of ester synthesis. The pretreated MBGs with dry reverse micellar solution exhibited lower water content and higher initial rates of esterification in comparison with untreated freshly prepared MBGs. The esterification efficiency of untreated MBGs started decreasing after 5 cycles of reuse and was almost completely lost by the end of the $8^{th}$ cycle. In contrast, pretreated MBGs exhibited a gradual decrease in esterification efficiency after 5 cycles and retained about 80% of the initial activity at the end of the $8^{th}$ cycle. The intermittent treatment of MBGs after every 3 cycles resulted in enhanced reusability of immobilized lipase for up to 9 cycles without significant loss in esterification activity, after which it resulted in a slow decrease in activity with about 27% lower activity at the end of the $12^{th}$ cycle. Furthermore, the treatment conditions such as concentration of AOT in liquid dessicant and time of treatment were optimized with respect to our system. The granulated MBGs proved to be better in terms of initial esterification rates (1.2-fold) as compared with the pelleted MBGs.

• Environmental Engineering Research
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• v.12 no.1
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• pp.8-15
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• 2007

Two phase UASB reactors for treating wastewater with sulfate were operated to assess the performance and competition of organics between sulfate reducing bacteria(SRB) and methane producing bacteria(MPB), and the change of characteristics of microorganisms. The reactors were fed in parallel with a synthetic wastewater of 4,000-5,000 mgCOD/L and sulfate concentration of $800-1,000\;mgSO_4/L$. In the MPR(methane producing reactor) and CR(control reactor), COD removal efficiencies were 90% and 60%, respectively, at the OLR(organic loading rate) of 6 gCOD/L, while the amount of biogas and methane content were 6.5 L/day and 80%, and 3 L/day and 50%, respectively. However, the portion of electron flow used by SRB at the OLR of 6 gCOD/L day in MPR and CR was 3% and 26%, respectively. This indicated that the increase of OLR of wastewater containing high sulfate like CR resulted in activity decrease and cell decay of MPB, while SRB was adapted immediately to new environment. The MPB activities in MPR and CR were 2 and $0.38\;kgCH_4-COD$/gVSS day at the OLR of 6 gCOD/L. This indicated hat SRB dominated gradually over MPB during long-term operation with wastewater containing sulfate as a consequence of outcompeting of SRB over MPB. In addition, the solution within AFR was maintained around pH 5.0, the MPB such as Methanothrix spp. which was very important to formation of granules was detached from the surface of granules due to the decrease of activity by limitation of substrate transportation into MPB. Therefore, a significant amount of sludge was washed out from the reactor.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.09a
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• pp.233-241
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• 2004

A new alloy definition will be presented concerning increasing demands for the board level reliability of miniaturized interconnections. The damage mechanism for LFBGA components on different board finishes is not quite understood. Further demands from mobile phones are the drop test, characterizing interface performance of different package constructions in relation to decreased pad constructions and therefore interfaces. The paper discusses the characterization of interfaces based on SnPb, SnPbXYZ, SnAgCu and SnAgCuInNd ball materials and SnAgCuInNd as solder paste, the stability after accelerated tests and the description of modified interfaces strictly related to the assembly conditions, dissolution behavior of finishes on board side and the influence of intermetallic formation. The type of intermetallic as well as the quantity of intermetallics are observed, primaliry the hardness, E modules describing the ability of strain/stress compensation. First results of board level reliability are presented after TCT-40/+150. Improvement steps from the ball formulation will be discussed in conjunction to the implementation of lead free materials In order to optimize ball materials for area array devices accelareted aging conditions like TCTs were used to analyze the board level reliability of different ball materials for BGA, LFBGA, CSP, Flip Chip. The paper outlines lead-free ball analysis in comparison to conventional solder balls for BGA and chip size packages. The important points of interest are the description of processability related to existing ball attach procedures, requirements of interconnection properties and the knowledge gained the board level reliability. Both are the primary acceptance criteria for implementation. Knowledge about melting characteristic, surface tension depend on temperature and organic vehicles, wetting behavior, electrical conductivity, thermal conductivity, specific heat, mechanical strength, creep and relaxation properties, interactions to preferred finishes (minor impurities), intermetallic growth, content of IMC, brittleness depend on solved elements/IMC, fatigue resistance, damage mechanism, affinity against oxygen, reduction potential, decontamination efforts, endo-/exothermic reactions, diffusion properties related to finishes or bare materials, isothermal fatigue, thermo-cyclic fatigue, corrosion properties, lifetime prediction based on board level results, compatibility with rework/repair solders, rework temperatures of modified solders (Impurities, change in the melting point or range), compatibility to components and laminates.