• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.26-31
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• 1995

Acetylcellulose(AC) was prepared with steam exploded wood(EXW) and EXW after delignification with sodium chlorite, pine (Pinus densiflora) and oak (Quercus mongolica) woods. The color of acetylated pine and oak exploded wood was brown, degree of substitution(D.S) of pine was 1.47~2.09, and this of oak was 1.49~2.29. The hemicellulose content of acetylated pine and oak exploded wood was 0~3.4% and 1.49~11.3%, individually. The degree of substitution of acetylated wood prepared from delignified EXW in the pine and oak wood was 0.50~0.71 and 0.70~0.88, individually. Hemicellulose content of acetylated EXW with sodium chlorite after delignification in the pine and oak wood was less than 1% and 0.6~2.5%. The color of acetylated wood after delignification was white. IR-spectra of acetylated pine and oak EXW after delignification were found that peaks at around 1740$cm^{-1}$ and 1200$cm^{-1}$ increase markedly, due to ester carbonyl group.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.494-502
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• 2016

A 1-dimensional heterogeneous reactor model with the gas-solid interfacial phase gradients was developed for the simulation of the packed bed reactor where the exothermic reversible water gas shift reaction for the natural gas steam reformed gas was proceeding in adiabatic mode. Experimental results obtained over the WGS catalyst, C18-HA, were best simulated when the frequency factor of the reaction rate constant was adjusted to a half the value reported over another WGS catalyst, EX-2248, having the same kinds of active components as the C18-HA. For the reactor of the inside diameter 158.4 mm and the bed length 650 mm, the optimum feeding temperature of the reformed gas was simulated to be $194^{\circ}C$, giving the lowest CO content in the product gas by 1.68 mol% on the basis of dried gas. For reactors more extended in the bed length, the possible lowest CO content in the product gas with the optimum feeding temperature of the reformed gas were suggested.

• Journal of Life Science
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• v.19 no.1
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• pp.65-74
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• 2009

The objective of this study was to examine the effects of steam flaking treatment of corn grains imported from USA and India on in vitro gas production, microbial growth and contents of aflatoxin $B_1$ and ochratoxin A. Each treatment was composed of total 4 treatments including (1) USCW (US com-whole type), (2) USCF (US corn-flaked type), (3) IDCW (India corn-whole type) and (4) IDCF (India orn-flaked type) with 4 replications $\times$ 6 incubation times (3, 6, 9, 12, 18 and 24 hr). Mycotoxin (aflatoxin $B_1$ & ochratoxin A) contents in test corns tended to increase gradually with increasing logistics periods from the harbor, hopper, silo to processing line. The contents of aflatoxin $B_1$ in India corn (IDCW) and US corn (USCW) were 11.71 and 1.78 ppb, respectively when measured at the hopper. After steam flaking, both contents of aflatoxin $B_1$ in USCW and IDCW were 0.00 ppb. It means that Aspergillus flavus could be decreased by steam flaking. However, this trend was not observed in ochratoxin content. The gas production rate of USA corns (USCW & USCF) was significantly (p<0.05) higher than India corns (IDCW & IDCF), and that of steam flaked corns (USCF & IDCF) was higher $1.5{\sim}2%$ than whole corns (USCW & IDCW) after 3 hr incubation in in vitro experiment. pH value was optimally maintained for microbial growth during whole incubation times with the value of 6.05 to 6.54, and was not significantly different between treatments, but USCF was somewhat lower than other treatments. pH value decreased following 12 hr of incubation but gas production increased rapidly during the same period. In addition, in vitro microbial growth rates also increased with up to 18 hr of incubation period, thereafter experienced a decrease with extended incubation time. In conclusion, US corn was superior to India corn by origin based on the results of in vitro and mycotoxin contents. And steam flaking process of imported corns tended to decrease mycotoxin contents such as aflatoxin $B_1$ and ochratoxin A as well as improve in vitro gas production and microbial growth rates.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2003.11a
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• pp.230-248
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• 2003

In this work an integrated model for paper plants combining wet-end and dry section is developed and a model predictive control scheme based on the plant model is proposed. Closed-loop process identification method is employed to produce a state-space model. Thick stock, filler flow, machine speed and steam pressure are selected as Input variables and basis weight, ash content and moisture content are considered as output variables. The desired output trajectory is constructed in the form of 1st-order dynamics. Results of simulations for control of grade change operations are compared with plant operation data collected during the grade change operations under the same conditions as in simulations. From the comparison, we can see that the proposed model predictive control scheme reduces the grade change time and achieves stable steady-state.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.69-77
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• 2001

'Chalok 1/Cooktail 51' corns, supersweet corn gene controlled by either brittle-l (bt l) or shrunken-2(sh2) gene introduced into waxy corn, showed agronomic characteristics between supersweet corn and waxy corn. The ears were harvested at different development stages from 15 to 35 days after silking (DAS). Ear diameter of Cocktail 51 and 'Cocktail 51'/Chalok 1 increased from 15 DAS to 30 DAS and little increased thereafter, but that of Chalok 1/Cocktail 51 and 'Chalok l' increased until 35 DAS. Diameter of ear extension increased more in Cocktail 51 and Chalok 1/Cocktail 51 corn than Chalok 1. Ear fresh weight of Cocktail 51 decreased later 30 DAS but those of the other hybrids were vice versa. Rate of super-sweet kernels per ear of Chalok 1/Cocktail 51 corns was about 38 %. Development, and elongation of kernel were much more prominent in supersweet kernel than in waxy kernel, but fresh weight increased higher in waxy kernel than supersweet kernel. Moisture content in kernel decreased from 15 DAS to 35 DAS. Total sugar content of the kernel increased until 25 DAS, and that of Cocktail 51 kernel showed the highest among of them. After cooked by steam, flavor and mastication feeling rate cooked by steam of Cocktail 51 and Chalok 1/Cocktail 51 were increased from 15 DAS to 25 DAS and markedly decreased thereafter. But those of Chalok l/Cocktail 51 and, Chalok 1 were decreased after 30 DAS. These results suggested that the optimum harvest date for fresh supersweet corn (Cocktail 51), Cocktail 51/Chalok 1 seems to be about 20 DAS and Chalok 1/Cocktail 51 and waxy com (Chalok 1) was about 25 DAS.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.43-52
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• 1995

To examine the appicability of the converter slag to aggregate, tests were performed for the converter slag specimens which were aged with steam, and the stability of expansion was investigated. The strength of the converter slag was found to he lower than that of the natural aggregate. But the strength of the concrete mixed with the converter slag and the granular slag was increased with an increase of the content of the granular slag. The slump value was larger for the specimen of the converter slag than that for the natural aggregate. The specific weight of the converter slag was decreased with an increase of the aging peroid. The aging time for the converter slag was accessed to be about 48 hours to accommodate the full stability of the expansion. The amount of the steam needed to age one ton of converter slag to full expansion was accessed to be 60 kg. From the regression analysis for splitting tensile strength (t), and flexural strength (f), the compressive strength (c) based on the following formulas were proposed $\sigma$t=0.1506 $\sigma$c+4.5(kg/cm$^2$) (r=0.876) $\sigma$f=O.l537.~+30.5(kg/cm$^2$) (r=0.796)

• Applied Biological Chemistry
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• v.37 no.1
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• pp.30-36
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• 1994

The essential oil of Schizandrae Fructus was extracted by simultanous distillation-extraction and steam distillation and analyzed by GC and GC-MS. The oil content of Schizandrae Frutus was 0.64% when extracted by steam distillation and 0.88% in case of simultanous distillation extraction and sensory analysis of the oil indicated woody, camphorous, spicy and sour characteristic notes. The experimental results confirmed the presence 47 volatile components, the major components were ${\gamma}-terpinene$, p-cymene, ${\alpha}-ylangne$ and ${\beta}-elemene$. The oil was fractioned into ten fractions and 4 fraction of them have a good aroma character. The application of the oil showed the utilization possibility as flavoring materials for Korea tea.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.1
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• pp.198-210
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• 2013

The purpose of this study investigates high school students' recognition and realities on the integrated science essay and is to suggest desirable direction of integrated science essay of how eduction. To this end, this paper was a questionnaire developed for use, it consists of the status, the writing skills and recognition of integrated science essay. Firstly, all grade students recognize the interest in integrated science essay class, but the need for third grade boys urgently was feeling. Second, STEAM class as a whole than average preference was. Third, integrated science essay was the most relevant, then was mathematics, languages, philosophy ethics, and social. Fourth, integrated science essay class with boys than girls in grade 1, science essay writing, reading science-related essay books, grammar, knowledge of the science and philosophy of science lessons, classes STEAM, read commentary essay reference all on the item, the higher affinity. Currently being implemented in integrated science essay test compared to the first, team teaching approach in schools project under one class teaches students how many teachers should be made. Second, it would require modifications of course content tailored to the preferences of female preference for science higher grade female students to disappear.

• International Journal of Industrial Entomology and Biomaterials
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• v.44 no.1
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• pp.21-27
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• 2022

Different parts of the mulberry plant are described to be potential sources of polyphenolics exhibiting strong antioxidant activity. In this study, we prepared various aqueous extracts of mulberry root bark by subjecting to steam at different temperatures and time intervals (45℃, 15 h; 70℃, 15 h; 95℃, 6 h and 95℃, 15 h) followed by extracting at 80℃ for 1 h. The total polyphenolic content ranged from 66.82-101.20 mg gallic acid equivalent (GE)/g of extract whereas the flavonoids were in the range of 13.03-25.23 mg catechin equivalent (CE)/g of extract. The extracts also exhibited strong antioxidant activities (0.99-1.66 mg trolox equivalent (TE)/g of extract in DDPH assay and 10.65-16.26 mg TE/g of extract in ABTS assay). This study clearly showed an improvement in the antioxidant activity of the water extract of mulberry root bark by the steam treatment, which can be used as a tea or health-promoting materials.

• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.73-84
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• 2015

In this research, two careers connectable with the contents of the curriculum of fifth to sixth grade elementary school students were selected among other promising future careers in biotechnology and medical engineering fields. 'Design-based promising future career STEAM program' was developed and its validity and effectiveness were verified. Reflecting recent issues, and complying with the STEAM standard (frame) instructional materials were developed through group deliberations for nine months, based on the achievement standards through an analysis of subject curriculum revised in 2009. This was prepared so that students are able to experience biotechnology and medical engineering related careers in a simulational form emphasized with creative design to make them prefer natural sciences and engineering careers and draw their interests and recognition of the relevant careers under the two disciplines. As a result of such application to STEAM Leader School students at the verification stage of the program, the contents and level of the program were verified suitable, receiving favorable reviews. And as a result of applying the developed program on other elementary school students, it was discovered that significant improvements were found in their career consciousness. Through this research, it was suggested that there is a need for a simplification of the curriculum content standards, a provision of 'standard for integration,' development of teachers' ability in reconstituting or organizing the STEAM and proceeding classes, continuous long-term support to see the effects of a policy or a program, and a reinforcement of career education integrated in the curriculum.