• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.467-472
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• 2017

In this study, the reforming reaction of vacuum residue (VR) was carried out using aquathermolysis reaction. VR showed a prone to decrease the amount of resins and asphaltenes in the constituents, and to increase saturates and aromatics when reacting with steam at 30 bar and above $300^{\circ}C$ for 24 h. This tendency became more evident when the amount of steam used was excessive than the amount of VR. When the aquathermolysis reaction was performed at $300^{\circ}C$ and 30 bar for 48 h, the VR composition was changed from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to final state (S/A/R/A = 6.8%/57%/12.2%/24.0%), and the contents of the resins decreased by 13% and the aromatic compounds increased by 13%. The viscosity decreased from 880,000 cp to 290,000 cp by 68%. When 10% of decalin, which is easy to provide hydrogen, was added, the viscosity decreased by 68% in 24 h. The VR composition showed a reduction in the contents of resins and asphaltenes from 49% to 17% from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to the final state (S/A/R/A = 4.5%/63.5%/12.5%/20.0%), and the content of aromatics was maximized to 63.5%. The gas layer formed by the aquathermolysis reaction in the reactor chamber was collected and analyzed by GC-MS spectroscopy. As a result, various hydrocarbon compounds such as ethylbenzene, octane and dimethylbenzene were detected.

• Journal of Conservation Science
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• v.22
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• pp.87-98
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• 2008

Microstructures and chemical compositions of 24 bronze mirrors recovered from the Korean peninsula were examined using the scanning electron microscope equipped with the energy dispersive spectrometer in an effort to characterize the treatments applied on their surface. Their provenance and chronology are mostly unspecified except for two objects from a Koryo burial site. In antiquity the surface of bronze mirrors was frequently finished by mere polishing when their tin content was high enough to guarantee the required reflectivity. In many cases, however, their surface was given a special treatment. The most typical treatment was to coat the surface with tin in two different processes referred to as wipe-tinning and amalgam-tinning. In wipe-tinning only tin was used, but in amalgam-tinning tin and mercury were used together. The surface was often coated with mercury in a process known as mercury-polishing. The present mirrors showed that all these techniques were in fact practiced, not only on the reflective surface but, in some cases, on the decorative surface. The detection of mercury played a crucial role in the assessment of a specific technique applied in each mirror. Mercury often remained in the substrate in the form of sulfide and thereby allowed the method of surface treatment to be estimated even when the coated layer was completely lost. The future study is expected to uncover the regional and temporal variation of the surface treatments to the better understanding of bronze mirrors with respect to provenance and chronology.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.255-263
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• 2004

Two experiments were conducted to evaluate the feeding values of sesame oil meal (SOM) and to investigate the effects of its dietary supplementation on egg production in laying hens. In experiment I, the values of true metabolizable energy (TME), nitrogen corrected true metabolizable energy (TMEn) and true amino acid availability (TAAA) were determined by force-feeding 16 ISA-Brown roosters and collecting the total excreta from the birds, The TME and TMEn of SOM were 2.30 and 1.99 kcal/g, respectively, and the average TAAA of 15 amino acids was $76.93\%$. In experiment 2, a total of ninety, 48 weeks old ISA-Brown layer were randomly divided into 9 groups of 10 birds each and assigned to three experimental diets containing 0, 5 and $10\%$ SOM for 4 weeks (30 birds per treatment). The inclusion of SOM into laying hen diets at the 5 and $10\%$ level did not affect production and quality of egg. The C18:3 $\omega$3 content of egg yolks in the $10\%$ SOM group was higher than the other groups, but not significantly. There were no adverse effects on blood parameters in layers fed treated diets containing $5\%$ or $10\%$ SOM, The results indicate that SOM can be used for layers diet up to $10\%$ without any significant negative effects on egg production and quality.

• Fire Science and Engineering
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• v.19 no.2 s.58
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• pp.105-110
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• 2005

We tested the char characteristics of fire retardant treated Douglas fir at each of five constant external irradiance levels $(10,\;15,\;20,\;25\;및\;35kW/m^2)$. A Cone heater was used to expose the wood specimens to the heat flux. The size of specimens is 100- by 100- by 50-mm and the kinds of specimens are non-treated wood(N) and treated wood(F2 and f4) by water soluble fire retardants. The water-soluble fire retardants were made from mixture of aqueous solutions of monoammonium phosphate, sodium borate and zinc borate, and those are used for immersion of Douglas fir. In result of test, char fraction of fire retardant treated Douglas fir showed a considerably low char fraction than it of non-treated wood irrespective of increase of external heat flux. And char fractions has low levels with increase of fire retardant content. Burning rate of non-treated wood(N) was showed a relatively high burning rate than it of fire retardant treated wood(F2 and F4). And difference of burning rate shown more rapidly in high external irradiance than low external irradiance. When the external heat flux is $35kW/m^2$, average char rate of non-treated wood is rapidly about twice than fire retardant treated wood. Water-soluble fire retardants mixed in this study find out it has fire suppression and adiabatic effect by char layer from results of char fraction, burning rate, and char depth and rate.

• Journal of Korea Multimedia Society
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• v.15 no.5
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• pp.651-663
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• 2012

Networked digital signage downloads necessary multimedia contents from a large-sized storage on WAN to its local disk of a limited size before starting their playback. If the required time to download the entire contents gets longer, a start time to play the contents at the digital signage could be delayed. In this paper, we propose a hybrid storage architecture that not only inserts an iSCSI storage layer between the existing local disk and the WAN storage, but offers a contents caching scheme in order to obtain all the necessary contents in digital signage rapidly. The proposed caching scheme determines how to place the downloaded contents both in the local disk and the iSCSI storage. Uniquely, the proposed caching scheme manages the iSCSI storage space by dividing it into two regions: (1) in one region, the digital signage can play the contents directly without downloading them into the local disk; (2) in the other region, the digital signage cannot. Performance evaluations on a simulator and an actual system with workloads of various contents show that a contents-downloading time of the hybrid storage architecture is at maximum three times shorter than that of the existing storage architecture.

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.49-55
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• 1986

In order to study the effects of probiotic and antibiotic on the performance of the chickens and the population of microfloras in the intestine, a feeding trial was conducted for a period of seven weeks. One hundred eighty hatched male chickens of layer attain were fed one of the following three experimental diets; nonmedicated control, antibiotic supplemented diet(virginiamycin 5 ppm) and probiotic supplemented diet. Birds fed probiotic supplemented diets were heavier and consumed more feed than those fed other diets but the differences were not statistically significant. Antibiotic supplemented group showed significantly (P〈0.01) better feed efficiency than other groups. Availabilities of dry matter, crude protein, crude fat, NFE, Ca and P were not significantly different between treatments but antibiotic supplemented group showed significantly(P〈0.05) lower availability of crude fiber than other groups. The weight of small intestine of the birds fed antibiotic supplemented diet was significantly (P〈0.05) lighter than those of other groups. The population of Bacillus subtilis and Lactobacilli in the intestinal content of the birds fed probiotic supplemented diet were significantly (P〈0.01) larger than those of other groups. On the other hand, the population of Coliforms in the probiotic group were significantly (P〈0.01) smaller than those in the nonmedicated control group.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.1
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• pp.37-45
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• 2017

To visually identify the spoilage of chicken breasts, a three layered freshness indicator consisting of PET/bromocresol green (BCG)-ethylene vinyl acetate (EVA)-acetic acid (AA) composite layer/porous substrates was successfully prepared and their performance were simulated at 20% of $CO_2$ and 4 different trimethylamine (TMA) concentrations to evaluate color change at minimal spoilage level. The visibility and range of color changes of the as-prepared indicators responding to TMA concentration as a simulant were strongly dependent on the concentrations of BCG and AA. As the BCG content increased, the visibility of color change in the freshness indicators was apparently improved and the range of color change could be controlled by contents of AA. Among the as-prepared freshness indicators, 'G0.12_A0.5' which consisting 0.12g of BCG and 0.5g of AA was selected as an optimum composition due to the highest visibility at TMA 20 mg% corresponding to the minimal spoilage level. The color of the indicator changed from yellow to green for spoilage indication of chicken breast, which could be easily seen with the naked eyes and well consistent with the simulation results. It is expected that our developed freshness indicator can be useful in monitoring various food freshness and quality.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.134-141
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• 2015

An agarolytic marine bacterium (H9) was isolated from the coastal seawater of the West Sea, South Korea. The isolate, H9, was gram-negative and rod-shaped with a smooth surface and polar flagellum. Cells grew at 20-30℃, between pH 5.0 and 9.0, and in ASW-YP (Artificial Sea Water-Yeast extract, Peptone) media containing 1-5% (w/v) NaCl. The G+C content was 41.56 mol%. The predominant isoprenoid quinone in strain H9 was ubiquinone-8. The major fatty acids (>10%) were C_16:1ω7c (34.3%), C_16:0 (23.72%), and C_18:1ω7c (13.64%). Based on 16S rRNA gene sequencing, and biochemical and chemotaxonomic characterization, the strain was designated as Pseudoalteromonas sp. H9 (=KCTC23887). In liquid culture supplemented with 0.2% agar, the cell density and agarase activity reached a maximum level of OD = 4.32 (48 h) and OD = 3.87 (24 h), respectively. The optimum pH and temperature for the extracellular crude agarases of H9 were 7.0 and 40℃, respectively. Thin-layer chromatography analysis of the agarase hydrolysis products revealed that the crude agarases hydrolyze agarose into neoagarotetraose and neoagarohexaose. Therefore, the new agar-degrading strain, H9, can be applicable for the production of valuable neoagarooligosaccharides and for the complete degradation of agar in bio-industries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.562-570
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• 2018

New physical properties of polymer materials were obtained by blending two or three different type of polymers. TPE is used widely in the display, automotive and electronics industries. Consumers have sought emotionally more sensitive and advanced interior automotive parts. A polymer with high foamibility (Ed note: Please check this.) and flowability would be more plausible. TPE composed of foam is a good polymer material to satisfy these trends. In this research, two different TPE were tested, focusing on foamibility and flowability. Two type of TPE were prepared. The first was blended Homo-PP, oil and SEBS. The second was Co-PP, oil and SEBS. The blending temperatures were $180^{\circ}C$, $190^{\circ}C$, and $260^{\circ}C$(second one). The blending speed was 50rpm and blending time was 5 min. The MI of the blended material was affected by the MI of PP and not affected by the blending temperature. The hardness and tensile elasticity were less affected by the MI of PP and blending temperature. The hardness and tensile elasticity were lower at a higher SEBS/Oil content ratio. The soft touch feel was higher with high SEBS/Oil contents. The IPN (Interpenentration polymer network) structure was observed by dissolving the SEBS/Oil layer in xylene. Strain-hardening phenomena also was observed. TPE behaves in a rubber and foamed closed-cell improved its stability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.115-132
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• 1992

This study was conducted to clarify the distribution pattern of macrobenthic soft-bottom dwelling animals near the shellfish farming ground in Chinhae Bay, Korea Sampling was seasonally performed with van Veen grab$(0.1m^2)$ from October 1990 to July 1991. Benthic animals collected during the study comprised 107 species which amounted to 6,978 individuals: 52 species from polychaetes$(48.6\%)$, 34 species from crustaceans$(31.8\%),$ 14 species from molluscs$(13.1\%)$ and 7 species from other faunal groups$(6.5\%)$. The dominant species were four polychaetes and one amphipod: Lumbrineis longifolia, Capitella capitate, Mediomastus sp., Sigambra tentaculata and Erictonius pugnax. The study area could be divided into 3 regions based on the faunal similarity which was closely related to the content of organic matter in the surface sediment. The benthic community located near the shellfish farming ground showed large spatial and seasonal variations in species diversity and evenness in contrast to the stable values off the farming area. The oxygen deficient water mass below 2 ml/l In thi bottom layer during the summer stressed and depauperated the benthic community in the autumn of 1990. However, the benthic community did recover during the winter. It is postulated that the cyclic phenomenon of summer mortality followed by winter recovery may be a common characteristic in benthic communities subjected to a high level of organic pollution.