• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1003-1007
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• 2013

In this study, the antibacterial activities of selected barleys (UB, unhulled barley; PB, pearl barley; and NB, naked barley) and wheat (WG, wheat with germ and endosperm) extracts were evaluated against the food-borne pathogens Staphylococcus aureus KCTC 1927, Escherichia coli KCTC 2593, Salmonella Typhimurium KCTC 2054, and Bacillus cereus KCTC 1014. The amount of the antibacterial biomarker, 2,6-dimethoxy-1,4-benzoquinone (DMBQ), present in selected barleys and wheat, was measured by HPLC. Furthermore, antioxidant activity of samples was determined using the oxygen radical absorbance capacity (ORAC) assay. WG ($22.35{\pm}0.04mm$) was found to be highly inhibitory to Staphylococcus aureus followed by UB ($17.91{\pm}0.10mm$), PB ($16.87{\pm}0.05mm$), and NB ($15.69{\pm}0.20mm$). The antibacterial activity of the selected grains was correlated with antioxidant activities and the amount of DMBQ (Pearson's correlation coefficient, 0.7831). The antioxidant activity of the selected grains was also correlated with the total phenolic content (Pearson's correlation coefficient, 0.9934). WG extract showed significantly higher antibacterial activity, compared with barley extracts such as UB, PB, and NB. The results of this study suggest that barley has a potential in the development of natural antimicrobials and food preservatives for controlling food-borne pathogens.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.4
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• pp.293-302
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• 1998

This study was performed to investigate the behavior of chlorobenzenes (CIBZS) and chlorophenols (CIPhs) in a thermally treated MSWI fly ash. The experiment was carried out in a fixed bed reactor at the temperature range of 300~$600^{\circ}C$. Reaction time range was between 30 and 120 minutes, and NB and 02 gases were used as carrier gas. The decomposition rate of CIBZS was more affected by reaction time than by the reaction temperature. The decomposition rate of CIPhs was affected by both parameters. Decomposition rate of CIBZS and CIPhs reached 80.4% and 96.6% at $600^{\circ}C$, 120 min, respectively. Considering the effect of O2 content, decomposition rate of CIBZS and CIPhs was the highest at 10% of O2 content. Declorination and decomposition reactions Pere investigated by analyzing homologue distribution. Higher chlorinated CIBZS and CIPhs homologue decreased but lower chlorinated compounds increased with the increase of temperature. Effect of O2 on the homologue distribution of these compounds was not clear in the range of our experiment conditions.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.4
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• pp.239-245
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• 2000

Effect of tin and iron content on the recrystallization behavior of temary Zr-0.8Sn-x%Nb alloys were studied. The specimens with 0.1, 0.2 and 0.4 wt.% of iron were prepared under various annealing temperatures from $400^{\circ}C$ to $800^{\circ}C$ and times from 30 to 5000 minutes after vacuum arc remelting. The recrystallization behavior was observed using a polarized optical microscope, TEM and micro-vickers hardness tester. The recrystallization temperature of the alloys slightly increased with iron content due to increase of activation energy. The grain growth of the alloys with 0.1 and 0.2 wt.% of iron occured rapidly, however, that of the alloys with 0.4 wt.% iron was gradually retarded due to precipitation. The hardness of the alloy with a high iron slightly increased by the precipitation of beta phase after annealing at $800^{\circ}C$.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.87-96
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• 2021

The demand for e-learning through video lectures is rapidly increasing due to its diverse advantages over the traditional learning methods. This led to massive volumes of web-based lecture videos. Indexing and retrieval of a lecture video or a lecture video topic has thus proved to be an exceptionally challenging problem. Many techniques listed by literature were either visual or audio based, but not both. Since the effects of both the visual and audio components are equally important for the content-based indexing and retrieval, the current work is focused on both these components. A framework for automatic topic-based indexing and search depending on the innate content of the lecture videos is presented. The text from the slides is extracted using the proposed Merged Bounding Box (MBB) text detector. The audio component text extraction is done using Google Speech Recognition (GSR) technology. This hybrid approach generates the indexing keywords from the merged transcripts of both the video and audio component extractors. The search within the indexed documents is optimized based on the Naïve Bayes (NB) Classification and K-Means Clustering models. This optimized search retrieves results by searching only the relevant document cluster in the predefined categories and not the whole lecture video corpus. The work is carried out on the dataset generated by assigning categories to the lecture video transcripts gathered from e-learning portals. The performance of search is assessed based on the accuracy and time taken. Further the improved accuracy of the proposed indexing technique is compared with the accepted chain indexing technique.

• Journal of Powder Materials
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• v.29 no.4
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• pp.325-331
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• 2022

Beta-titanium alloys are used in many industries due to their increased elongation resulting from their BCC structure and low modulus of elasticity. However, there are many limitations to their use due to the high cost of beta-stabilizer elements. In this study, biocompatible Ti-Mo-Fe beta titanium alloys are designed by replacing costly beta-stabilizer elements (e.g., Nb, Zr, or Ta) with inexpensive Mo and Fe elements. Additionally, Ti-Mo-Fe alloys designed with different Fe contents are fabricated using powder metallurgy. Fe is a strong, biocompatible beta-stabilizer element and a low-cost alloying element. The mechanical properties of the Ti-Mo-Fe metastable beta titanium alloys are analyzed in relation to the microstructural changes. When the Fe content increases, the tensile strength and elongation decrease due to brittle fracture despite a decreasing pore fraction. It is confirmed that the hardness and tensile strength of Ti-5Mo-2Fe P/M improve to more than 360 Hv and 900 MPa, respectively.

• Journal of Magnetics
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• v.11 no.1
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• pp.43-50
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• 2006

In this paper, the influences of microstructural and surface morphological developments on the soft magnetic properties and giant magneto-impedance (GMI) effect of the $Fe_{73.5-x}Cr_{x}Si_{13.5}B_{9}Nb_{3}Au_1$ (x = 1, 2, 3, 4, 5) alloys have been presented. It was found that the Cr addition slightly decreased the mean grain size of $\alpha-Fe(Si)$ grains. AFM results indicate a large variation of surface morphology of density and size of protrusions along the ribbon plane due to microstructural changes caused by thermal annealing with increasing Cr content. Ultrasoft magnetic properties of the nanocrystallized samples were noticeably enhanced by properly heat treatments at $T_a=540^{\circ}C$ such as an increase of the magnetic permeability and the decrease of coercivity, which is likely due to the formation of nanoscale $\alpha-Fe(Si)$ phase which reduced the magnetoelastic anisotropy of samples. Accordingly, the GMI effect was observed in the annealed samples. The correlation between the microstructure, surface morphology, and soft magnetic properties were explained by nucleation and growth model.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.162-170
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• 1998

The dose response effects of different levels of wheat barn (WB) supplementation to a rice straw based diet has been studied in growing native (Bos indicus) bulls of Bangladesh. Twelve bulls of $266{\pm}29.6kg$ live weight and $32{\pm}9.5$ months old were given either of three diets of ad libitum untreated rice straw alone (T1) or straw supplemented with 2 (T2) or 3 (T3) kg WB. Besides, the experimental animals also received a mineral mixture. In 4 weeks, data were recorded on the intake, digestibility, microbial N (MN) yield, N balance (NB) and growth rate (GR). In the three diets, WB was 0 (T1), 29.6 (T2) and 42 (T3) percent of the total DM intake. With the increasing levels of WB supplementation, the total DM and OM intake increased, but the straw intake decreased linearly. WB supplementation increased the digestibilities of DM, OM and N but had no effect on ADF digestibility. The urinary purine derivative excretion and hence the MN yield increased with WB supplementation. The total MN yield were 7.26 and 35 g/d respectively for 0.2 and 3 kg WB supplementation. However, the efficiency of MN yield was highest (13 g/kg DOMR) at 2 kg WB level. Despite the increase DOM intake, the dietary ME content remain below 6 MJ/kg DM even at 3 kg WB supplementation. The NB were -84,467 and 1,620 mg/kg $W^{0.75}/d$ which were reflected on the GR of -186,346 and 554 g/d for 0, 2 and 3 kg WB supplementation respectively. Depending on the cost effectiveness, on an untreated rice straw diet, WB may be supplemented by up to 3 kg/d (42% of the diet) or more. However, if the maximum utilization of roughage is the main concern, the optimum WB level would probably be around 2 kg (30% of the diet) daily.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.2
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• pp.75-82
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• 2005

Recently the needs of high reliable substances of high strength and high ductility are gradually increased with the development of aerospace industry. The characteristics of maraging steel has high ductililty, formability, corrosion resistant and high temperature strength and is easy to fabricate, weld and treat with heat, and maintain an invariable size even after heat treatment. e steels are furnished in the solution annealed condition and they achieve full properties through martensitic precipitation aging a relatively simple, low temperature heat treatment. As is true of the heat treating procedures, aging is a time/temperature dependent reaction. Therefore, the objective of this stud)'was consideration of fatigue characteristics according as Nb(niobium) content and time/temperature of heat treatment change. Also the stress analysis, fatigue lift, and stress intensity factor were compared with experiment results and FEA(finite element analysis) result. The maximum ftresses of)( Y, and Z axis direction showed about $2.12\times$10$^{2}$MPa, $4.40\times$10$^{2}$MPa and $1.32\times$10$^{2}$MPa respectively. The fatigue lives showed about $7\%$ lower FEA result than experiment result showing almost invariable error every analyzed cycle. Stress intensity factor of the FEA result was lower about $3.5~ 10\%$ than that of the experiment result showing that the longer fatigue crack ten添 the hi인or error. It considered that the cause for the difference was the modeled crack tip having always the same shape and condition regardless of the crack growth.

• Journal of the Korean Society for Heat Treatment
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• v.21 no.5
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• pp.244-250
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• 2008

This study has investigated the surface phase change, hardness variation, surface precipitates, nitrogen content and corrosion resistance in STS 431 (17Cr-2Ni-0.2C-0.01Nb) martensitic stainless steel after high temperature gas nitriding (HTGN) treatment at the temperature range between $1050^{\circ}C$ and $1150^{\circ}C$. The HTGN-treated surface layer appeared $Cr_2N$ of rod type, carbo-nitride of round type and fine precipitates in the austenite matrix. On the other hand the interior region where the nitrogen was not permeated, exhibited martensite phase. The surface hardness showed 250~590 HV, depending on the HTGN treatment conditions, while the interior martensitic phase represented 520 HV. The permeation depth of nitrogen increased with increasing the HTGN-treated temperature. The nitrogen concentration of the surface layer appeared approximately ~0.17% at $1100^{\circ}C$. On comparing the corrosion resistance between solution-annealed and HTGN-treated steels, the corrosion resistance of HTGN-treated steel was superior to that of solution-annealed specimens.

• Korean Journal of Poultry Science
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• v.26 no.1
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• pp.43-50
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• 1999

The features of special brand eggs are growing more and more diverse and it is hard to draw a clear distinction between these and ordinary (no-brand) eggs. Special brand eggs range from those with objectively recognizable characteristics to those given only an unsubstantial product image and price differentials are among them great, too. The relation between product features and prices is unclear. Special brand eggs are the commodity whose characteristics are the vaguest of all livestock products. Farm's brand eggs produce a high profitability to producers is they are directly sold to consumers, by, for example, home-delivery service. But if they are sold to supermarkets, etc., producer's (poultry farmer's) income becomes lower by the amount of distributors' margin, reducing the profitability substantially. Thus how to increase the ration of retailing is important for farmers to secure a high profit. The sales strategies of poultry are the combination of two elements, that is, new product development (product differentiation) and creation of new market. But it is difficult for special brand egg producers to develop products with clear characteristics (use value) distinct form ordinary eggs and so these producers depend on the factors of appearance, such as the color of egg shells and package. Special brand eggs manage to keep their marketable value by the combination of the few product features and product image. Thus NB eggs from feed producers have a great market-ability since they can take advantage of the power of patents and TV commercials. However, market differentiation affects profitability much more than product features and price gaps are very wide between directly sold and wholesaled eggs. The producers of special brand eggs have come to the turning point where they have to decide whether they will content with being the subcontractors for NB and PB eggs or they will continue to keep their independence in production and marketing.