• Journal of Surface Science and Engineering
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• v.41 no.5
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• pp.181-188
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• 2008

A.C. impedance properties of HA/Ti compound layer coated Ti-30Ta-($3{\sim}15$)Nb alloys have been studied by electrochemical method. Ti-30Ta binary alloys contained 3, 7, 10 and 15 wt% Nb were manufactured by the vacuum furnace system. And then specimen was homogenized at $1000^{\circ}C$ for 24 hrs. The sample was cut and polished for corrosion test and coating. It was coated with HA/Ti compound layer by magnetron sputter. The non-coated and coated morphology of Ti alloy were analyzed by X-ray diffractometer (XRD), energy X-ray dispersive spectroscopy (EDX) and filed emission scanning electron microscope (FE-SEM). The corrosion behaviors were investigated using A.C. impedance test (PARSTAT 2273, USA) in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. Ti-30Ta-($3{\sim}15\;wt%$)Nb alloys showed the ${\alpha}+{\beta}$ phase, and $\beta$ phase peak was predominantly appeared in the case of increasingly Nb contents. The microstructures of Ti alloy were transformed from needle-like structure to equiaxed structure as Nb content increased. From the analysis of coating surface, HA/Ti composite surface uniformed coating layer with 750 nm thickness. The growth directions of film were (211), (112), (300) and (202) for HA/Ti composite coating on the surface after heat treatment at $550^{\circ}C$, whereas, the growth direction of film was (110) for Ti coating. The polarization resistance ($R_p$) of HA/Ti composite coated Ti-alloys were higher than those of the Ti and HA coated samples in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. Especially, corrosion resistance of Ti-Ta-Nb system increased as Nb content increased.

• Journal of Astronomy and Space Sciences
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• v.25 no.2
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• pp.139-148
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• 2008

It has been known that high-speed solar wind streams associated with coronal holes lead to quasi-periodic substorms that occur approximately every $2{\sim}4$ hours. In this paper we examined 222 repetitive substorms that occurred during high-speed stream periods in July through December in 2003 to quantitatively determine a range of energy input from the solar wind into the magnetosphere between two consecutive substorms. For this study, we have used the Akasofu ${\varepsilon}$-parameter to time-integrate it for the interval between two consecutive substorms, and have applied this method to the 222 substorms. We find that the average amount of solar wind input energy between two adjacent substorms is $1.28{\times}10^{14}J$ and about 85% out of the 222 substorms occur after an energy input of $2{\times}10^{13}{\sim}2.3{\times}10^{14}J$. Based on these results, we suggest that it is not practical to predict when a sub storm will occur after a previous one occurs purely based on the solar wind-magnetosphere energy coupling. We provide discussion on several possible factors that may affect determining substorm onset times during high-speed streams.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.639-646
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• 2007

To evaluate the effect of fiber sources on chewing activity, five sheep were consecutively fed diets containing 45% of a fiber source selected from 7 tested fiber sources of alfalfa hay cube(AHC), corn cob (CC), corn silage(CS), cotton seed hull(CSH), peanut hull(PHL), rice straw(RS) and sugarcane bagasse (SCB). Number of chew showed significantly higher value in CC(p<0.001) then other sources. RS and CC had highest(p<0.01) rumination times of 352 and 367 min/d, respectively. CC also showed the highest number of chew per kg NDF intake(p<0.01), but rumination time per kg NDF intake showed no difference except CSH(p<0.001). These results suggest that chewing activities were greatly affected by the fiber sources, and therefore it should be accounted in the formulation for ruminant feed.

• The Korean Journal of Physiology
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• v.8 no.2
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• pp.75-78
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• 1974

It was planned to investigate, by observing incorporation of $[^3H]$ thymidine into liver cells, the influence of Panax Ginseng upon hepatic DNA synthesis in mice that received ACTH. Thirty male mice $(body\;weight:\;18{\sim}20\;g)$ were divided equally into the ginseng-ACTH and the saline-ACTH groups. Each animal of the ginseng-ACTH and the saline-ACTH groups received every day (subcutaneously) 0.05 m1/10 g body weight of ginseng extract (4 mg of ginseng alcohol extract in 1 ml of saline) and the same amount of saline, respectively, for 5 days. On the 5th experimental day, all animals received 0.01 unit of ACTH intraperitoneally one hour. after the last medication, and $1{\mu}Ci/g$ body weight of $[^3H]$ thymidine after one more hour. Five animals, at a time, of each group were sacrificed 1, 10, and 24 hours after thymidine administration, and their hepatic radioactivity was measured autoradiographically in terms of the % number of radioactive cells in 1,000 cell counts (Radioactive Index, R.1.). Following results were obtained: 1. The hepatic radioactive indices obtained from the saline-ACTH group 1, 10, and 24 hr after $[^3H]$ thymidine administration were $1.50{\pm}0.32,\;2.16{\pm}0.33\;and\;2.79{\pm}0.31\;(mean{\pm}S.D.)$, respectively. 2. The corresponding values obtained from the ginseng-ACTH group $(2.71{\pm}0.22,\;3.85{\pm}0.29,\;and\;5.06{\pm}0.31)$ were significantly higher than the values of the saline-ACTH group. It is inferred from the above results that the ginseng tends to prevent reduction in hepatic DNA synthesis caused by ACTH administration.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.642-655
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• 2013

In this study, semi-continuous measurements of $PM_{2.5}$ mass, organic and elemental carbon (OC and EC), black carbon (BC), and ionic species concentrations were made for the period of April 03~13, 2012, at a South Area Supersite at Gwangju. Possible sources causing the high concentrations of major chemical species in $PM_{2.5}$ observed during a haze episode were investigated. The measurement results, along with meteorological parameters, gaseous pollutants data, air mass back trajectory analyses and PSCF (potential source contribution function) results, were used to study the haze episode. Substantial enhancements of OC, EC, BC, $K^+$, $SO{_4}^{2-}$, $NO{_3}{^-}$, $NH{_4}{^+}$, and CO concentrations were closely associated with air masses coming from regions of forest fires in southeastern China, suggesting likely an impact of the forest fires. Also the PSCF maps for EC, OC, $SO{_4}^{2-}$, and $K^+$ demonstrate further that the long-range transport of smoke plumes of forest fires detected over the southeastern China could be a possible source of haze phenomena observed at the site. Another possible source leading to haze formation was likely from photochemistry of precursor gases such as volatile organic compounds, $SO_2$, and $NO_2$, resulting in accumulation of secondary organic aerosol, $SO{_4}^{2-}$ and $NO{_3}{^-}$. Throughout the episode, local wind directions were between 200 and $230^{\circ}C$, where two industrial areas are situated, with moderate wind speeds of 3~5 m/s, resulting in highly elevated concentration of $SO_2$ with a maximum of 15 ppb. The $SO{_4}^{2-}$ peak occurring in the afternoon hours coincided with maximum ambient temperature ($24^{\circ}C$) and ozone concentration (~100 ppb), and were driven by photochemistry of $SO_2$. As a result, the pattern of $SO{_4}^{2-}$ variations in relation to wind direction, $SO_2$ and $O_3$ concentrations, and the strong correlation between $SO_2$ and $SO{_4}^{2-}$ ($R^2=0.76$) suggests that in addition to the impact of smoke plumes from forest fires in the southeastern China, local $SO_2$ emissions were likely an important source of $SO{_4}^{2-}$ leading to haze formation at the site.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.4
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• pp.31-44
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• 1985

The application of anaerobic attached microbial films in the expanded bed process has recently been examined at high temperatures ($55^{\circ}C$) and with particulate matter. Extrapolation of the kinetics suggested that waste activated sludge (WAS) could be efficiently digested at hydraulic retention times as short as six hours in the expanded bed process. This would represent a 99 percent digester reactor volume reduction and would introduce interesting solids management alternatives if such a high rate process were developed. This paper presents a summary of a 1.5 year study of the feasibility of such a process. Three continuously fed $55^{\circ}C$ laboratory reactor systems were used to define the kinetics and the site of reactions-control completely mixed reactors were compared to the expanded beds (AAFEB) with and without a hydrolysis unit preceding the attached film unit. Well defined laboratory-generated WAS was compared to actual WAS from a domestic sewage treatment facility. Sixty percent of the biodegradable organics were converted in an AAFEB at a 15-hour hydraulic retention time without hydrolysis, whereas greater than 95 perccent of the biodegradable organics were stabilized in a two-stage system consisting of a 3-day HRT hydrolysis reactor followed by a 15-hour HRT AAFEB. The limitations of this high rate process and its potential application are discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1469-1474
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• 2003

Twenty four weaner lambs, eight each of Marwari, Patanwadi and Merino${\times}$Patanwadi breeds (9.9 to 10.8 kg) were randomly divided into two dietary treatments on body weight basis Viz. $T_1$-conventional (Maize-38%, GN Cake-25%, Rice Polish-24%, Jaggery solution-10%, Mineral mixture-3%) and $T_2$-supplemented non conventional group (GN Cake-25%, Rice Polish-14%, Mango seed kernel-25%, Babul Pods chuni-23%, Jaggery solution-10%, Mineral mixture-3%). The Jaggery solution was prepared by mixing 6.5 kg Jaggery and 3.5 kg water. The average final body weight at the end of the experiment was recorded to be $19.33{\pm}0.76$ and $19.72{\pm}0.8kg$ in conventional and non-conventional groups, respectively. The total dry matter intake (DMI) during the entire experiment period was recorded to be $89.56{\pm}5.19$ and $95.08{\pm}1.06$ (kg/head) and $532.83{\pm}9.94$ and $566.75{\pm}10.49g/d$ in conventional and nonconventional groups, respectively. The body weight gain and body measurements did not influenced by diet. The ration effect was found to be significant when the DMI was expressed in terms of g/d. The crude protein (CP) and digestible crude protein (DCP) intake/head and per kg gain observed during experiment under conventional and non-conventional treatment group did not differ from each other. However, the total digestible nutrients (TDN) intake per kg gain was significantly (p<0.05) higher in supplemented non-conventional group. The intake values of DCP and TDN were more or less in agreement with Indian Council Agricultural Research (1985) recommendations. The estimated total feed cost (Rs./animal) for experimental lambs was $274.16{\pm}8.57$ and $242.67{\pm}5.10$ in conventional and non- group, respectively. The non-conventional group had significantly (p<0.05) lower feed cost (11.6%). The return as percent of feed cost and feed cost/kg dressed weight were $92.89{\pm}5.58$ (%) and Rs. $35.40{\pm}1.11$ and $122.61{\pm}5.06$ (%) and Rs.$30.47{\pm}1.71$ in conventional and non-conventional group (p<0.05), respectively which is the reflection of significantly lower total feed cost incurred during feeding in non-conventional group. Lambs fed non-conventional based diet had similar live weights as those fed conventional diets but costed less money to achieve those weights.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.273-280
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• 2019

BACKGROUND: The reclaimed lands for agricultural use managed by the Korean government is consisted of 17,145 hectares of lands under construction and 13,384 hectares of completed lands. In order to utilize these reclaimed lands as competitive agricultural complexes, the government is preparing to develop comprehensive development plans for multiple purposes. For rational land-use planning and soil management, information of the soil chemical properties is necessary. METHODS AND RESULTS: From 2013 to 2016, soil samples were collected from 85 representative sampling sites of the reclaimed lands and analyzed for soil chemical properties including electric conductivity (EC), pH, soil organic matter (SOM), and nutrients. The annual mean soil EC ranged from 5.1 to 8.3 dS m^-1 and have continued to decrease over the years (estimation equation with EC as dependent and year as independent variable was y =0.0736x² - 1.4985x + 9.8305, R² = 0.9753). The pH ranged from 7.3 to 7.6, which was higher than the optimum range (5.5~7.0) for agricultural soils. Soil organic matter (8 to 11 g kg^-1) was lower level than the optimum range (20~30 kg^-1). Available silicate (Av.SiO₂) ranged from 169 to 229 mg kg^-1, which was close to the minimum content (≥157 mg kg^-1) for rice paddy field. Available phosphate (Av.P₂O₅) content (24~39 mg kg^-1) was lower than the optimum range (80~120 mg kg^-1) for rice paddy field. CONCLUSION: For efficient agricultural use of reclaimed lands under government management, our results suggest that the application of organic matter and supplying deficient nutrients as well as desalinization is required.

• KSBB Journal
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• v.29 no.5
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• pp.316-322
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• 2014

Xylanase have been used to convert the polymetric xylan into fermentable sugars from the production of ethanol and xylitol from plant biomass. The aim of this study was to isolate and identify xylanolytic bacterium from herbivore feces and was to used the xylanase for enzymatic hydrolysis of biomass. Xylanolytic strains were isolated from 59 different feces of herbivores from Seoul Grand Park located in Gwacheon Gyeonggi-do. The xylanolytic strains were selected by congo red staining and DNS method. Total 67 strains isolated from the herbivores feces were tested for xylanase activity. Among the strains, H10-1, which has the highest xylanase activity, was isolated from feces of Ceratotherium simum. The H10-1 strain was identified as Bacillus pumilus based on its morphological/biochemical characteristics and partial 16S rDNA gene sequences. Culture conditions of B. pumilus H10-1 such as initial medium pH, incubation temperature and incubation time were optimized for maximum xylanase production. And also xylanase produced by B. pumilus H10-1 was applied for the saccharification of Miscanthus sacchariflorus cv. 'Geodae 1', which was pretreated with 1.5M NaOH. The optimized culture conditions of B. pumilus H10-1 were pH 9, $30^{\circ}C$ incubation temperature, and 7 day incubation time, respectively. This xylanase activity under the optimized conditions was $20.4{\pm}3.3IU$. The crude xylanase produced by B. pumilus H10-1 was used for the saccharification of xylan derived from pretreated 'Geodae 1'. The saccharification conditions were $50^{\circ}C$, 200 rpm, and 5 days. Saccharification efficiency of pretreated 'Geodae 1' by B. pumilus H10-1 was 8.2%.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.200-205
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• 2015

Perilla frutescens var. japonica Hara was collected from farmland in Seongju-gun. Fifteen endophytic fungal strains with different colony morphologies were isolated from roots of P. frutescens. Waito-c rice seedlings were treated with the concentrated culture filtrates (CF) of endophytic fungi for observation of their plant growth-promoting activities. In the results, the CF of Y2H001 fungal strain promoted the growth of the waito-c rice seedlings. The phylogenetic tree of Y2H001 strain was analyzed by the combined sequences of the partial internal transcribed spacer region (ITS) and partial betatubulin gene. Molecular and morphological studies identified the Y2H001 strain as belonging to Aspergillus flavus. In gas chromatography mass spectrometry (GC/MS) analysis of the CF of Y2H001 strain, gibberellic acid (GA) was detected and quantified. Therefore, we describe Y2H001 strain as a new $GA_3$-producing A. flavus based on morphological, molecular characteristics and analysis of secondary metabolite.