• Corrosion Science and Technology
• /
• 제21권2호
• /
• pp.111-120
• /
• 2022

To solve the corrosion problem of industrial equipment and other constructions containing metals, corrosion protection can be performed by using coating which provides a barrier between the metal and its environment. Coatings play a significant role in protecting irons and steels in harsh marine and acid environments. This study was conducted to identify an anti-corrosive epoxy coating for carbon steel composite with 0.1, 0.3, and 0.5 wt% concentrations of nanoparticles of SiO₂ using the dip-coating method. The electrochemical behavior was analyzed with open circuit potential (OCP) technics and polarization curves (Tafle) in 3.5 wt% NaCl and 5 vol% H₂SO₄ media. The structure, composition, and morphology were characterized using different analytical techniques such as X-ray Diffraction (XRD), Fourier Transform Infrared spectrum (FT-IR), and Scanning Electron Microscopy (SEM). Results revealed that epoxynano SiO₂ coating demonstrated a lower corrosion rate of 2.51 × 10^-4 mm/year and the efficiency of corrosion protection was as high as 99.77%. The electrochemical measurement showed that the nano-SiO₂ / epoxy coating enhanced the anti-corrosive performance in both NaCl and H₂SO₄ media.

• Korean Journal of Medicinal Crop Science
• /
• 제7권3호
• /
• pp.155-161
• /
• 1999

This study was carried out to develop the propagation system using in vitro induced- microtubers of yams (Dioscorea alata L.). Effects of kinds of media, mineral composition, sucrose concentration (0, 2, 4, 6, 8, 10%), photoperiod (0, 8, 12, 16, 24h), and growth regulators (NAA, IAA, ZR, JA-Me, ABA) on the development of microtubers, roots, and shoots in nodal stem segment cultures of D. alata L. were evaluated. Microtuberization in nodal stem segment occurred on all the media supplemented with growth regulator and sucrose. Among basic media, 1/2MS medium was the best in microtuber induction. NAA was shown to be the most effective among the growth regulators. Optimal NAA concentration was 1mg/l. The microtuberization was the highest at the concentration of 6% sucrose. When the nodal stem segment were cultured under darkness, the tuberization was increased markedly compared to those cultured under light condition. It was also noticeable that the culture in medium with NAA produced only microtubers and roots, but no shoots, in nodal segments. In this study, the optimal medium composition for microtuberization in nodal stem segment was found to be 1/2MS medium supplemented with 1mg/l NAA and 6% sucrose under dark condition at $25^{\circ}C$.

• Journal of Applied Biological Chemistry
• /
• 제54권4호
• /
• pp.252-257
• /
• 2011

To remove excess nitrate from the agricultural environments, Enterobacter amnigenus GG0461 has been isolated as a bacterial strain having high capability of nitrate uptake activity. This strain was able to remove nitrate more than 3,000 ppm (50 mM) in the Pseudomonas agar F (PAF) medium. Therefore, it could be a candidate strain for a nitrate scavenger in the various contaminated environments, such as agricultural soils, livestock sewage, and industrial wastewater. In order to develop medium for the large-scale production of the strain GG0461, each component of PAF medium was replaced with the corresponding commercial product and the optimal conditions for bacterial growth and nitrate uptake activity were measured. Glycerol was replaced with the commercially available product and the nitrogen source was substituted with commercial tryptone, yeast extract, soybean meal, and fermented fish extract. Bacterial growth and nitrate uptake activity were maximal in the media containing 2% tryptone, followed by yeast extract, soybean meal, and fermented fish extract. The pH of the growth medium containing 2% tryptone was decreased by the bacterial nitrate uptake, suggesting that the nitrate uptake is mediated by a nitrate/proton antiporter. This result shows that the medium containing commercial tryptone was good enough for the physiological activity of the strain GG0461. Each component of PAF medium was successfully replaced with the corresponding commercial product except peptone. In conclusion, the composition of medium for the cultivation of the strain GG0461 was determined as 2% tryptone, 1% glycerol, plus required salts according to the composition of PAF medium.

• Journal of Mushroom
• /
• 제11권4호
• /
• pp.208-213
• /
• 2013

The contents of raw materials which are components of mixed substrate for mushroom cultivation were analyzed to optimize the composition. The pure protein(amino acid) level of soybean meal was the highest, 44.02% followed by those of soybean curd residue(31.5%) and cotton seeds meal(30.6%). The non protein nitrogen(NPN) contents in crude protein of main nitrogen materials were 2.4% for soybean meal and 5.6% for dried soybean curd residue, while those of wheat bran and rice bran used as the carbon source were relatively higher, 17.6% compared to that of nitrogen supplying media. Crude protein content per price was 6.0 for rapeseed meal, indicating that it is high crude protein content per price. Nitrogen-free extract(NFE) considering as an ingredient for mycelial growth were high in alphacorn(72.9%) and wheat bran B(57.2%). Acid detergent fiber(ADF) was high in corncob, 51.88%, its use for cultivation of brown rot fungi including Lentinus lepideus should pay attention because the fungi lack complete lignin degradation activity.

• Korean Journal of Plant Resources
• /
• 제37권3호
• /
• pp.263-269
• /
• 2024

Embryos of early-ripening peaches could not achieve physiological maturation or undergo abortion before harvest. Embryo rescue is an effective strategy to rescue embryos from early-ripening peaches. Thus, the current study was carried out to determine the appropriate developmental stage and optimal medium composition for embryo rescue in early-ripening peach. Development of open-pollinated 'Yumi' fruit was investigated from 20 to 90 days after full bloom (DAFB) to explore period occurring endocarp hardening. After endocarp hardening, embryo development was observed by light microscopes. Shoot and root meristems were observed at 65 DAFB and embryo size rapidly increased at 75 DAFB. Embryos collected at 75, 80, 85, and 90 DAFB were cultured on four media based on Driver and Kuniyuki (DKW) medium. Germination rate of embryos cultured on four media gradually increased from 75 to 90 DAFB and reached 100% at 90 DAFB. Notably, M3 medium (0.5 DKW supplemented with 6-benzylaminopurine (BAP) 1.0 ㎎/L) displayed the highest germination rate at 75 and 80 DAFB stages. Growth and development of shoot and root were pronounced in plantlet cultured at 90 DAFB stage. While delayed shoot growth was evident in plantlets cultured at 75, 80, and 85 DAFB stages, this retardation could be overcome through the application of growth regulators, particularly in M3 and M4 (0.5 DKW supplemented with BAP 1.0 ㎎/L and indole-3-butyric acid 0.5 ㎎/L) media. Remarkably, roots of plantlet grown in M4 medium exhibited limited elongation. In conclusion, germination rate of embryo and growth of embryo cultured plantlet can be enhanced by collecting seeds from early-ripening 'Yumi' at the 90 DAFB stage and conducting embryo culture using the M3 medium.

• Journal of the Korean Society of Radiology
• /
• 제16권3호
• /
• pp.309-317
• /
• 2022

It is reported that social distancing caused by the corona pandemic has resulted in a decrease in physical activity, and a decrease in muscle mass due to this increases the risk of vascular disease. Therefore, in this study, the risk of carotid intima media thickness was evaluated by measuring the thickness of CIMT, and the differences in variables according to gender were analyzed. From January 2022 to May 2022, a total of 220 people (121 males, 99 females) who performed blood tests, carotid ultrasound, and body composition analysis among those who visited the health check-up center of Busan H Hospital were included in this study. Significant differences in risk factors according to gender were analyzed using the chi-square test. The cut-off values of variables that can predict the risk of carotid intima media thickness were calculated, and the accuracy was evaluated by calculating the area under the curve, sensitivity, and specificity. As a result of the difference analysis, the higher the total cholesterol in men and the appendicular skeletal muscle index in women, the higher the risk of carotid intima media thickness. The cut-off value for predicting the risk of carotid intima media thickness was calculated to be greater than 199 mg/dL of total cholesterol in the male group and less than 5.9 kg/m² of the appendicular skeletal muscle index in the female group. As a result of this study, the higher the total cholesterol in men and the lower the appendicular skeletal muscle index in women, the higher the risk of increased CIMT. Therefore, in women, the appendicular skeletal muscle index is expected to serve as an indicator to predict and prevent vascular changes at an early stage.

• Korean Journal of Soil Science and Fertilizer
• /
• 제45권6호
• /
• pp.910-919
• /
• 2012

The role of inorganic nitrogen assimilation in the production of amino acids, organic acids and soluble sugars is one of the most important biochemical processes in plants, and, in order to achieve normally, nitrate uptake and assimilation is essential. For this reason, the characterization of nitrate assimilation and metabolite composition from leaves, roots and xylem sap of tomato (Solanum lycopersicum) was investigated under different nitrate levels in media. Tomato plants were grown hydroponically in liquid culture under five different nitrate regimes: deficient (0.25 and 0.75 mM $NO_3{^-}$), normal (2.5 mM $NO_3{^-}$) and excessive (5.0 and 10.0 mM $NO_3{^-}$). All samples, leaves, roots and xylem sap, were collected after 7 and 14 days after treatment. The levels of amino acids, soluble sugars and organic acids were significantly decreased by N-deficiency whereas, interestingly, they remained higher in xylem sap as compared with N-normal and -surplus. The N-excessive condition did not exert any significant changes in metabolites composition, and thus their levels were similar with N-normal. The gene expression and enzyme activity of nitrate reductase (NR), nitrite reductase (NIR) and glutamine synthetase (GS) were greatly influenced by nitrate. The data presented here suggest that metabolites, as a signal messenger, existed in xylem sap seem to play a crucial role to acquire nitrate, and, in addition, an increase in ${\alpha}$-ketoglutarate pathway-derived amino acids under N-deficiency may help to better understand plant C/N metabolism.

• Ocean and Polar Research
• /
• 제24권4호
• /
• pp.407-417
• /
• 2002

Species composition and abundance of zooplankton were investigated around Dokdo in the East/Japan Sea in autumn 1999 and spring 2000. Vertical and horizontal hauls of a bongo net ($300{\mu}m$ mesh size, 60cm diameter) were made to collect zooplankton sample. Surface temperature and salinity ranged from $24.2^{\circ}C\;to\;25.1^{\circ}C$, and from 32.9psu to 33.2psu in September 1999, respectively. In May 2000, surface temperatures were $13.9^{\circ}C\;and\;14.2^{\circ}C$ at stations of A1 and A8, and salinity was 34.5psu at both stations. Zooplankton community was dominated by copepods which comprised 61% (September) and 60% (May) of total numerical abundance, respectively. The next dominant groups were appendicularians (11%) and chaetognaths (9%) in September 1999, and other crustaceans (27%) and appendicularians (4%) in May 2000. The 15.7% (September) and 23.2% (May) of copepods were in the juvenile stage of copepodites. The most dominant copepods were Oncaea media (10.4%) and Clausocalanus sp. (8.2%) which preferred warm water in September. In contrast, cold-water copepods such as Pseudocalanus minutus (9.4%) and Metridia pacifica (8.0%) were dominant in May. The results of cluster analysis based on Bray-Curtis index showed that zooplankton community were classified into two groups which represented different water mass. The average abundance of zooplankton in September was 2.1 times higher than that in May, and species number of them in September outnumbered that in May by 29 species. Zooplankton community varied in associated with a characteristic of warm waters which affected marine ecosystem differently in the study area depending on seasons.

• Bulletin of the Korean Chemical Society
• /
• 제28권7호
• /
• pp.1097-1103
• /
• 2007

We report a novel method to synthesize nanocomposites composed of titania nanoparticles and phosphotungstate ions with various composition ratios ranging from W/Ti = 12/10 to 12/500 by inducing the electrostatic interaction between the positively charged protonated titania sol-particles and the negatively charged phosphotungstate anions to flocculate and precipitate. The precipitates showed varied features depending on the composition. The precipitate from the tungsten-richest W/Ti = 12/10 reaction is amorphous in its powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy data. This material shows the Type II adsorption characteristics in its N2-adsorption isotherm, but with quite low surface area of 34 m2/g. To the contrary, the precipitates from the titanium-richer reactions (W/Ti = 12/50- 12/500) are composed of anatase nanoparticles of 2-6 nm by XRD, TEM and Raman and show the Type I adsorption characteristics. The surface area linearly increases with the titanium content from 131 m2/g for W/ Ti = 12/50 to 228 m2/g for 12/500. The precipitate from the reaction with the intermediate composition W/Ti = 12/20 is composed of anatase nanoparticles and does not have any pore accessible to N2. With the wide variety of the physical properties of the precipitates, the present method can be a novel, viable means to tailor synthesis of nanocomposite materials. A formation mechanism of the precipitates is based on the electrostatic interactions between the titania nanoparticles and phosphotungstate ions.

• Journal of Broadcast Engineering
• /
• 제21권4호
• /
• pp.525-537
• /
• 2016

In this paper, we develop an online video mash-up system which use automatic scene elements composition scheme using a storyboard. There are two conventional online video production schemes. Video collage method is simple and easy, but it was difficult to reflect narrative or story. Another way is a template based method which usually select a template and it replaces resources such as photos or videos in the template. However, if the related templates do not exist, there are limitations that cannot create the desired output. In addition, the quality and atmosphere of the output is too dependent on the template. To solve these problems, we propose a video mash-up scheme using storyboard and we also implement a classification and recommendation scheme based on topic modeling.