• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.9
• /
• pp.1268-1273
• /
• 2011

The present study was conducted to determine a feasible method of protein concentrate extraction from rice bran (RBPC) and its effect as a substitution for skim milk in early weaning pig diets. An investigation to extract protein concentrate from full fat rice bran was undertaken to determine the best ratio of water and rice bran, the amount of NaOH and a HCl solvent to use in a simple paddle-type mixer with modified spinning to produce RBPC. The results stated that the best ratio for water mixing in the RBPC extraction process was 1:5 with 20 g NaOH and 30 min in a paddle-type mixer at 300 rpm. A mix of 250 ml 0.2 N HCl was optimum for neutralization and protein precipitation. After the fluid was spun out with a washing machine, the sediment was left for 12-14 hours to complete the filtration. One kilogram of rice bran could produce an average of 324.5 gram RBPC and it contained 3.40% ash, 496.48 kcal of GE/100 gram, 1.94% crude fiber, 28.20% ether extract, 7.64% moisture and 16.66% crude protein, respectively. A total of 45 crossbred piglets, weaned at 3 weeks of age were allotted into control diet (A) and dietary treatments formulated with a four different rates of RBPC substitution for skim milk at a percentage of 25 (B), 50 (C), 77 (D) and 100 (E) respectively, in a randomized complete block (RCB) design. All piglets had free access to feed and water until 8 week of age when the experiment ended. Feed intake, average daily gain, growth rate and feed efficiency were not affected by dietary treatments. Blood test parameters after completion of the growth trial indicated normal health. Even though the mean of cell hemoglobin concentration was significantly different between treatments (p<0.05) it was still within the normal range. The cost difference for BW gain of 100% RBPC substituted for skim milk in the weaning diet was approximately 35% lower than that of the control and the relative cost of production was 96.67, 92.85, 70.75 and 64.48% lower for the replacement of 25, 50, 75 and 100% of skim milk respectively. These results implied that this technology is feasible for use by small scale farmers to improve their self-reliance.

• Journal of Nutrition and Health
• /
• v.37 no.10
• /
• pp.908-916
• /
• 2004

Due to the common dietary practice of preparing foods in various ways using the same food item, in addition to rather a large number of food items that average Koreans consume, it is difficult to accurately assess the nutritional adequacy. In an effort to identify a reliable means of assessing the nutritional adequacy of Korean adults, we analyzed the association between the scores of dietary diversity (DDS) and dietary variety (DVS), and the quality of nutrient intake as assessed by Nutrient Adequacy Ratio (NAR) and Mean Adequacy Ratio (MAR). A three day-dietary record was obtained from each of 324 inhabitants, aged 40 to 69 years (mean :t SD,52.4 $\pm$ 8.7), of a rural area (Ansung) and a mid-sized city (Ansan) of Korea. These individuals were randomly selected among the participants of the Korean Health and Genome Study. The number of consumed foods and food groups were assesses by DDS (scored 1 to 5) and DVS (ranked 30 $\leq$,31 - 40, 41 - 50, 51 - 60, and 60 <) over three-day period, respectively. As DDS/DVS increased, mean daily food intakes tended to increase, and NARIMAR was improved. Thus, DDS and DVS were significantly correlated with the quality of nutrient intake. Over 95% of the subjects scored less than 2 in DDS for the first one-day period, whilst over 62% recorded 4 during the full three-day period (p < .0001). The mean number of consumed food items increased from 24.9 to 44.4 as a function of days of the record period (p < .0001). We also analyzed the association of DDS and DVS with MAR, using regression analysis, controlling age and sex as covariates. For DDS, the adjusted coefficient determination (adj $R^2$) values were 8.7%,15.8%,23.3% of MAR, also increasing as a function of the record duration, whereas they were 27.3%, 33.3%, 37.6% for DVS, respectively, demonstrating that NAR/MAR has a better correlation with DVS than DDS. Our data show that DDS, and DVS in particular, are useful parameters for evaluating nutrient intake in the Korean population. Our data also support that one day-dietary records are by no means adequate for accurately describing a wide variety of food choices offered for average Koreans, and that dietary assessment at least for 3 days or longer should be obtained for a reliable evaluation of dietary quality using DDS or DVS.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.12
• /
• pp.1982-1992
• /
• 2019

The alkaliphilic, calcium carbonate precipitating Bacillus sp. strain AK13 can be utilized in concrete for self-repairing. A statistical experimental design was used to develop an economical medium for its mass cultivation and sporulation. Two types of screening experiment were first conducted to identify substrates that promote the growth of the AK13 strain: the first followed a one-factor-at-a-time factorial design and the second a two-level full factorial design. Based on these screening experiments, barley malt powder and mixed grain powder were identified as the substrates that most effectively promoted the growth of the AK13 strain from a range of 21 agricultural products and by-products. A quadratic statistical model was then constructed using a central composite design and the concentration of the two substrates was optimized. The estimated growth and sporulation of Bacillus sp. strain AK13 in the proposed medium were 3.08 ± 0.38 × 10⁸ and 1.25 ± 0.12 × 10⁸ CFU/ml, respectively, which meant that the proposed low-cost medium was approximately 45 times more effective than the commercial medium in terms of the number of cultivatable bacteria per unit price. The spores were then powdered via a spray-drying process to produce a spore powder with a spore count of 2.0 ± 0.7 × 10⁹ CFU/g. The AK13 spore powder was mixed with cement paste, yeast extract, calcium lactate, and water. The yeast extract and calcium lactate generated the highest CFU/ml for AK13 at a 0.4:0.4 ratio compared to 0.4:0.25 (the original ratio of the B4 medium) and 0.4:0.8. Twenty-eight days after the spores were mixed into the mortar, the number of vegetative cells and spores of the AK13 strain had reached 10⁶ CFU/g within the mortar. Cracks in the mortar under 0.29 mm were healed in 14 days. Calcium carbonate precipitation was observed on the crack surface. The mortar containing the spore powder was thus concluded to be effective in terms of healing micro-cracks.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.11 no.4
• /
• pp.97-104
• /
• 2003

Hydrogen fermentation of food waste and sewage sludge was performed in serum bottles under various volatile solids(VS) concentrations(0.5~5.0%) and mixing ratios of two substrates(0:100-100:0, VS basis). Full quadratic equations, optimal conditions, and 90% acceptable conditions for hydrogen production potential and rate were obtained using cumulative methane production data and response surface methodology. The specific hydrogen production potential of food waste was higher than that of sewage sludge. However, hydrogen production potential increased as sewage sludge composition increased up to 13~19% at all the VS concentrations. The maximum specific hydrogen production potential of 122.9 mL/g $carbohydrate_{added}-COD$ was found at the waste composition of 87:13(food waste:sewage sludge) and the VS concentration of 3.0%. The relationship between carbohydrate concentration, protein concentration, and hydrogen production potential indicated that enriched protein by adding sewage sludge might enhance hydrogen production potential. The maximum specific hydrogen production rate was 111.2 mL $H_2/g$ VSS/h. Food waste and sewage sludge were, therefore, considered as a suitable main substrate and a useful auxiliary substrate, respectively, for hydrogen production.

• The Korean Journal of Pharmacology
• /
• v.24 no.1
• /
• pp.111-123
• /
• 1988

Neutrophil elastases were purified by a three step procedure consiting of one Sephadex G-75 and two HPLC elutions. The elastases cross-reacted with antibodies to human neutrophil elastase. Three bands with molecular weights between 26,000 and 29,700 were observed by gel electrophoresis. At each stage of purification the quantity of Zn increased, reaching molar ratio of 2:1 with elastase in the most purified samples. Calcium content. was seletively elevated during the earlier stages of purification but decreased to a ratio of 0.25 to 1 with elastase at the final step of purfication. Neutrophil elastase could be inhibited by EDTA, EGTA and 1,10-phenanthroline. EGTA inhbition was noncompetitive inhibition and reversible only if the time of preincubation was relatively short, indicating the instability of the apoenzyme. The concentration of chelator required to show significant inhibition of elastase was also dependent upon the stage of purity and the ionic strength of the reaction mixture. Inhibition by EGTA, followed by the removal of EGTA, could be reversed by Zn. In the presence of EGTA the enzyme could be returened to full activity by the addition of Zn, Mn and Ca, but not Mg or Na. All of the above evidence strongly supports human neturophil elastase could be a metalloenzyme as well as a serine protease.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.7
• /
• pp.1-7
• /
• 2016

In this paper, the design methodology of a corrugated conical horn antenna is proposed to be obtain wide-band properties over the full range of frequencies in the Ku-band. In order to improve the properties of the corrugated conical horn antenna, such as its gain, VSWR, co-polarization to cross-polarization ratio and wide-bandwidth, two types of mode matching converters are implemented within it. One is located at the end of the circular waveguide, while the other is positioned in front of the horn-flare section. The properties of the antenna are analyzed and compared according to the position of the proposed converters through simulations. In the comparison of the antenna performance in the case where the VSWR, co-polarization to cross-polarization ratio and antenna gain over the Ku band of 12-18 GHz are less than 2, greater than 30dB and 20dB respectively, the former antenna exhibits greater stability and a wider frequency band than the latter from the viewpoint of transmitting and receiving signals simultaneously. Therefore, considering the gain, VSWR, radiation pattern and bandwidth, the horn antenna structure in which the mode matching converter is implemented inside the circular waveguide has better performance than the other.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.5A
• /
• pp.511-520
• /
• 2011

In this paper, we introduce a multiuser (MU) scheduling method for multiuser amplify-and-forward relay systems, which selects both the transmission mode, i.e., either one- or two-hop transmission, and the desired user via two steps. A closed-form expression for the average achievable rate of the proposed scheduling is derived under two transmission modes with MU scheduling, and its asymptotic solution is also analyzed in the limit of large number of mobile stations. Based on the analysis, we perform our two-step scheduling algorithm: the transmission mode selection followed by the user selection that needs partial feedback for instantaneous signal-to-noise ratios (SNRs) to the base station. We also analyze the average SNR condition such that the MU diversity gain is fully exploited. In addition, it is examined how to further reduce a quantity of feedback under certain conditions. The proposed algorithm shows the comparable achievable rate to that of the optimal one using full feedback information, while its required feedback overhead is reduced below half of the optimal one.

• Journal of Korean Society of Forest Science
• /
• v.101 no.2
• /
• pp.236-243
• /
• 2012

The leaf growth and physiological characteristics of Forsythia saxatilis were investigated at six natural habitats under different light intensities in Bukhansan in order to figure out an appropriate growth environment for conservation and restoration of F. saxatilis that is Korean endemic plant designated as rare and endangered species. Relative light intensities (RLI) at six habitats showed from 10% to 78% of the full sun. Leaf length, leaf width, leaf area and dry leaf weight of population under highest relative light intensity (78%) were the highest. The ratio of dry leaf weight to leaf area increased with the increase of RLI. The content of photosynthetic pigments such as chlorophyll a, b and carotenoid were the highest at 78% of RLI, whereas the ratio of total chlorophyll to carotenoid content reduced according to the increase of RLI. Photosynthetic parameters, such as photosynthetic rate, also increased with the increase of RLI. The total nonstructural carbohydrate (TNC) was 1.5 times higher at 78% of RLI than that at 10% of RLI and the total soluble sugar (TSS) was the highest at 78% of RLI. In conclusion, leaf characteristics and physiological characteristics have high positive correlation with light intensity. Therefore, light condition should be primarily considered to improve growth and physiology characteristics of F. saxatilis under low light intensity.

• Communications for Statistical Applications and Methods
• /
• v.16 no.4
• /
• pp.627-637
• /
• 2009

Our economic system highly depends on the international trade market and demands high level of foreign language abilities to the young generation. Scores of various internationally authorized language tests are used to estimate students's language ability before giving their admission to universities or high schools. According to increase of unemployment rate of the young people, universities put their strength on the language abilities of their students, and each university uses some authorized language scores before determining students who win scholarships. This study suggests two types of indices to evaluate students's relative achievement of foreign language abilities between two time points considering their current abilities. One, named one-side relative achievement index, is defined as the ratio of additional score between two time points to the remaining score at the base time point to the full score. The second one, named two-side relative achievement index, is defined as the same manner as the first one if the score is improved, and if not, is defined as the ratio of the amount of losing scores to the current score at the base time point. Two-side achievement index is more useful since it has smaller variation than the former and is easier to interpret. However, both indices are useful to compare the achievements of different tests.

• Fire Science and Engineering
• /
• v.26 no.2
• /
• pp.75-83
• /
• 2012

An experimental study was conducted to investigate the effects of change in heat release rate on unsteady fire characteristics of under-ventilated fire in a semi-closed compartment. A standard doorway width of the full-scale ISO 9705 room was modified to 0.1 m and the flow rate of heptane fuel was increased linearly with time using a spray nozzle located at the center of enclosure. Temperature, heat flux, species concentrations and heat release rate were continuously measured and then global equivalence ratio (GER) concept was adopted to represent the unsteady thermal and chemical characteristics inside the compartment. It was observed that there was a significant difference in unsteady behavior between global and local combustion efficiency, and the GERs predicted by ideal and measured heat release rate were also shown different results in time. The unsteady behaviors of temperature, heat flux and species concentrations were represented well using the GER concept. It was important to note that CO concentration was gradually decreased with the increase in GER after reaching its maximum value in the range of 2.0~3.0 of global equivalence ratio. In addition, the experimental data on unsteady thermal and chemical behaviors obtained in a semi-closed compartment will be usefully used to validate a realistic fire simulation.