• Journal of the Korean Magnetics Society
• /
• v.10 no.4
• /
• pp.171-177
• /
• 2000

Exchange coupling of Co/NiMn bilayers fabricated by RF magnetron sputtering method was studied. We investigated the variation of exchange coupling field (H$\sub$ex/) for different annealing temperature and time. The maximum exchange coupling field was obtained after 13hr annealing at 300 $^{\circ}C$. With respect to deposition sequence, it was demonstrated that NiMn-top bilayers had higher exchange coupling field than NiMn-bottom bilayers. Ta capping layer was shown to be essential in achieving exchange coupling and Auger Electron Spectroscopy (AES) proved that uncapped NiMn/Co bilayers did not have exchange coupling because of oxygen incorporation into film. We also observed the effect of Ta underlayer on exchange coupling. It was found that Ta underlayer had better not be used for attaining higher exchange coupling. XRD analysis showed that Ta underlayer helped bilayers develop texture, but it was not essential to exchange coupling of Co/NiMn bilayers, which is in contrast to NiFe/NiMn system. Furthermore, the NiMn and Co thickness dependence of exchange coupling has been investigated. The exchange coupling strength reached the maximum above 200 ${\AA}$ NiMn thickness and had inversely proportional relation with Co thickness.

• Korean Journal of Soil Science and Fertilizer
• /
• v.31 no.4
• /
• pp.400-406
• /
• 1998

To investigate the effect of simulated acid rain on the change in soil chemical properties, simulated acid rain of different pH was applied to the three soils of different texture. Simulated acid rain of pH 4.0 and 6.0 did not greatly change the soil pH, while simulated acid rain of pH 2.0 decreased greatly the soil pH. Decrease in soil pH were in the order of sandy loam > loam > clay loam, while increase in exchangeable acidity was in the order of clay loam > loam > sandy loam. Amount of nutrients leached downward due to the penetration of simulated acid rain into the soil was in the order of Ca > K > Mg. Exchangeable Al was not detected when soil acidity dropped to pH 5 and exchangeable acidity increased within a range of CEC. A total 1200mm of simulated acid rain(pH 3.0) can load $12kg\;ha^{-1}$ of $H^+$ ion, $128kg\;ha^{-1}$ of sulfur, $56kg\;ha^{-1}$ of nitrogen. The acidity of simulated acid rain pH 3.0 can be neutralized by addition of $444kg\;ha^{-1}$ of slaked lime. The amount of leached bases were equivalent to 923, 1731 and $1608kg{\cdot}ha^{-1}$ in sandy loam, loam and clay loam soil respectively.

• Journal of Mushroom
• /
• v.17 no.3
• /
• pp.167-170
• /
• 2019

Cultivation of brown mushrooms, rather than that of white variants is preferred by Korean mushroom farmers, as the former are resistant to diseases. However, brown mushrooms were cultivated only in selective eco-friendly agricultural farms due to lack of consumer awareness. After providing information about brown mushrooms to respondents through a 1-minute video clip, a survey was conducted on social network service (SNS) to assess recognition and preference for brown mushrooms. A food evaluation was then conducted among 200 people randomly selected from the survey respondents. Most respondents (83%) had not encountered brown button mushrooms previously, and 98% of the respondents were willing to buy these mushrooms because they were "curious about its taste" (44%). In the food evaluation, 32% of the respondents found the brown button mushrooms to be delicious, 28% reported a good flavor, and 31% described a good texture. In addition, we confirmed that 95% of respondents were interested in purchasing brown mushrooms after sampling. Therefore, in the present study, we evaluated public perception, preference, and taste of brown button mushrooms, and confirmed that availability of information on nutrition and benefits s of mushroom consumption could induce consumers to buy brown button mushrooms.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.47 no.1
• /
• pp.1-7
• /
• 2021

With increasing interest in the effectiveness and safety of sunscreen worldwide, research on the development of new inorganic sunscreen is also gaining momentum. In the present study, non-nano sized needle type zinc oxide, which can meet the regulation of nano-material as a recent problem, has been synthesized and surface-modified with cetyl alcohol to obtain needle type zinc oxide powder. Here, we also investigated their physical properties and evaluated their potential application as sunscreens. As a result of the experiment, the sunscreen with needle type zinc oxide powder, which was non-nano, showed similar UV-protection properties and transparency compare to that of 40nm size zinc oxide. It was further confirmed that the UV blocking effect was significantly increased when the needle type zinc oxide dispersion was applied to the sunscreen. Therefore, although the needle type zinc oxide is non-nano (200 nm) material, it has the potential to be applied to the product as an excellent transparency (improvement of whiteness), UV protection efficacy and smooth texture.

• Journal of the East Asian Society of Dietary Life
• /
• v.24 no.2
• /
• pp.190-200
• /
• 2014

In this study, the antioxidant activity and quality characteristics of the Korean traditional food jeung-pyun made with ju-bak powder were investigated. Jeung-pyun added with 10% ju-bak powder had a total polyphenol content of 54.27%, DPPH free radical scavenging activity of 91.98%, reducing power of 0.51% and SOD-like antioxidant activity of 18.21%. Jeung-pyun added with ju-bak powder had a moisture content of 52.65 to 46.94%, crude fat content of 1.61 to 1.29%, crude protein content of 3.50 to 4.66%, crude ash content of 0.68 to 0.82% and dietary fiber content of 0.12 to 1.46%. Ju-bak powder added with jeung-pyun had a pH level from 4.86 to 4.39. As ju-bak content increased, the pH decreased significantly. Color L value were 78.82 to 68.67. As ju-bak content increased, the Color L value content decreased significantly; a value ranged from -1.89 to 0.69 and b value from 2.99 to 14.25. As ju-bak content increased, the color content significantly increased. As ju-bak content increased, the volume significantly decreased (ranged from 42.50 to 30.00 mL), hardness, gumminess and chewiness significantly increased, and cohesiveness significantly decreased. From SEM, as ju-bak content increased, the pores merged and collapsed, whereas the number of pores decreased and pore size became larger. Sensory evaluation of color, flavor, taste, texture, appearance, cell uniformity and overall acceptability for various levels of ju-bak powder showed that 10% had the highest acceptability. Therefore, 10% ju-bak power added with jeung-pyun has both high antioxidant capacity and sensory acceptability.

• Journal of the Korean Electrochemical Society
• /
• v.14 no.4
• /
• pp.196-200
• /
• 2011

The formation of niobium oxide microcones on niobium substrates was investigated in NaF to the HF electrolytes. This condition builds on the uniqueness of the microstructures niobium oxide. The dimensions and integrity of the bulk microstructures were found to be strongly dependent on potential, temperature, electrolyte composition, and anodization time. The anodic oxide was initially amorphous at all temperatures, but crystalline oxide nucleated during anodization. From XRD patterns of the anodized specimens, the microcones consisted of crystalline $Nb_2O_5$. We demonstrated niobium oxide microcone structures with nanorods. The anodized niobium oxide microcone texture revealed nanorod bundles. The surface of $Nb_2O_5$ microcones is very regular and has a nano-scale. The surface morphologies of the nanorods were examined using FE-SEM. EDS analyses show that the anodically prepared niobium oxide consists of $Nb_2O_5$. The aim of this study is to find the condition of forming the favorable nanorods by anodization method.

• Korean Journal of Environmental Agriculture
• /
• v.38 no.4
• /
• pp.245-253
• /
• 2019

BACKGROUND: Weathering of bottom ash (BA) might induce change of its surface texture and pH and affect physical and chemical properties of soil associated with greenhouse gas emission, when it is applied to the arable soil. This study was conducted to determine effect of weathering of BA in mitigating emission of greenhouse gases from upland soil. METHODS AND RESULTS: In a field experiment, methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) emitted from the soil was periodically monitored using closed chamber. Three month-weathered BA and non-weathered BA were applied to an upland soil at the rates of 0, 200 Mg ha^-1. Maize (Zea mays L.) was grown from July 1_st to Oct 8_th in 2018. Both BAs did not affect cumulative CH₄ emission. Cumulative CO₂ emission were 23.1, 19.8, and 18.8 Mg/ha/100days and cumulative N₂O emission were 35.8, 20.9, and 17.7 kg/ha/100days for the control, non-weathered BA, and weathered BA, respectively. Weathering of BA did not decrease emission of greenhouse gases significantly, compared to the weathered BA in this study. In addition, both BAs did not decrease biomass yields of maize. CONCLUSION: BA might be a good soil amendment to mitigate emissions of CO₂ and N₂O from arable soil without adverse effect on crop productivity.

• Food Science of Animal Resources
• /
• v.40 no.1
• /
• pp.55-73
• /
• 2020

Poultry meat is generally exposed to quality deterioration due to lipid oxidation during storage. Oxidative stability of meat can be increased by feed supplementation. Aim of the current study was to investigate the effect of dietary supplementation of fish waste derived bioactive peptides on antioxidant potential of broiler breast meat and physico-chemical characteristics and quality parameters of nuggets prepared from breast meat. 180 broiler birds (six groups of 30 birds) were purchased. Each group was given different concentrations of bioactive peptides i.e. 0, 50, 100, 150, 200, and 250 mg/kg feed. After completion of six weeks birds were slaughtered and breast meat was stored at -18℃ for six months. Nuggets were prepared and stored at -18℃ for 45 days. Meat samples were analyzed for antioxidant activity [total phenolic contents (TPC), DPPH^· scavenging activity, and ferric reducing antioxidant power] and lipid oxidation assay at regular intervals of 1, 2, 3, 4, 5, and 6 months while nuggets were analyzed for quality (pH, color, texture and water holding capacity) parameters after regular interval of 15 days. A significant (p<0.05) effect of feed supplementation was observed on antioxidant status such as TPC, DPPH^· scavenging activity, and FRAP of broiler breast meat. Dietary interventions of bioactive peptides significantly (p<0.05) delayed lipid oxidation of breast meat than control. All the quality parameters were also significantly affected due to dietary bioactive peptides and storage duration. Thus, dietary interventions of bioactive peptides can increase the antioxidant and shelf stability of broiler breast meat and nuggets.

• Journal of Animal Science and Technology
• /
• v.48 no.4
• /
• pp.563-574
• /
• 2006

This study was performed to investigate if high molecular weight(～200kDa) of chitosan can be a potential possibility to replace with the sodium nitrite in low-fat sausages. pH, proximate analysis, Hunter color values, vacuum purge, expressible moisture(EM, %), texture profile analysis(TPA), shelf-life effect were measured. No differences in physico-chemical properties were observed between controls and chitosan treatments(p>0.05). Since Hunter-a-values(redness) were reduced with the addition of chitosan as compared to the sausages containing sodium nitrite and sodium lactate, it could not be replaced by chitosan completely. However, total plate counts(TPC), thiobarbituric acid reactive substance(TBARS), volatile basis nitrogen(VBN) did not differ between chitosan treatments and controls. These results indicated that the addition of chitosan into meat products would be replaced with sodium nitrite partially, but it may not be completely replaced due to the reduced Hunter-a-values. Further research will be continuously performed to screen the natural ingredients which might have a cured pigment in meat products.

• Journal of Korea Multimedia Society
• /
• v.17 no.1
• /
• pp.26-33
• /
• 2014

Video retrieval and indexing are performed by comparing feature similarities between key frames in shot after detecting a scene change and extracting key frames from the shot. Typical image features such as color, shape, and texture are used in content-based video and image retrieval. Many approaches for integrating these features have been studied. However, the issue of these approaches is how to appropriately assign weighting of key frame features at query time. Therefore, we propose a new video retrieval method using adaptively weighted image features. We performed computer simulations in test databases which consist of various kinds of key frames. The experimental results show that the proposed method has better performance than previous works in respect to several performance evaluations such as precision vs. recall, retrieval efficiency, and ranking measure.