• Journal of Biosystems Engineering
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• v.14 no.1
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• pp.16-23
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• 1989

An oscillating potato digger for power tillers was designed and constructed to evaluate the effects of vibration on potato digging. Changing the levels of amplitude, frequency, and travel speed, 16 combinations of such parameters were tested in the potato field. The measured variables were harvesting loss and damage, and storing loss of the mechanically harvested potatoes. It was observed that the operation of the digger blade was good with amplitude of 12 mm, frequency of 9.67 Hz, and travel speed of 0.87 km/hr. Under these conditions the harvesting loss and damage were 3.18 % and 0.67 % that are very lower than those of 6.83 % and 9.83 % of traditional harvesting method. The operating efficiency of the experimental digger under optimum operating conditions was about 552 $m^2$ per hour which was about 20 times higher than 27.2 $m^2$ per man per hour of traditional harvest.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.161-161
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• 1998

To achieve the aim of this investigation, the extracellular protease was isolated from bacteria BAC-4, a strain was cultivated in the medium for the production of penicillin acilase in a period of 32 hours. The enzyme was first purified by aceton precipitation method, followed by ion exchange chromatography on DEAE-sephacel column. The highest specific activity of the aceton fraction was found to be 2.19 unit per mg, with degree of purification of 13 times. Further purification of the enzyme on DEAE -sephacel had a specific activity of 58.6 unit per mg and degree of purification of 344 times compared to its crude extract. The optimum pH of the enzyme was 8.4, and the potimum temparature was 37$^{\circ}C$. The K$\_$M/ and $V_{max}$ calculated at experiment conditions were found to be 0.66%(W/V) and 3.61 unit per mL respectively.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.635-641
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• 2012

In Korea, slurry composted and biofiltered (SCB) liquid fertilizer is produced through the composting and biofiltering of animal waste. An appropriate guidelines involving proper treatment of SCB liquid fertilizer on turfgrass should be considered. An experiment was conducted to determine the optimum application amount, timing, and frequency of SCB liquid fertilizer for Zoysia japonica 'Millock'. The SCB liquid fertilizer was applied in low, medium, and high amount (N at 15, 25, and 40 $g{\cdot}m^{-2}$ per year in 2010, and 10, 20, and 40 $g{\cdot}m^{-2}$ per year in 2011, respectively) and treated during the growing season or dormancy period. During the growing season, SCB liquid fertilizer was applied twice or four times. The greatest improvement in turf quality for both years was in SCB plots applied four times with N at 40 $g{\cdot}m^{-2}$ per year during the growing season (SH4). This treatment exhibited turf color retention in the fall, and enhanced clipping yield during the growing and fall seasons. SCB plots with four times during the growing season (SL4, SM4, and SH4) exhibited higher shoot density relative to the same amount of other SCB treatments. Plots treated during the dormancy period also showed a high turf color index during the next growing season in 2011. The results indicate that SCB with high amount up to N at 40 $g{\cdot}m^{-2}$ per year applied four times during the growing season and dormant application produced high turf quality and growth, and could be recommended as an optimum application guide.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.393-398
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• 2013

The purpose of this study was to determine how an ornamental fish, such as the fighting fish, Betta splendens would respond to the use of freshwater live-prey, such as rotifers Brachionus calyciflorus and water fleas Moina macrocopa. Ingested quantity, digestive velocity and somatic growth were compared between larvae fed a freshwater rotifer and those fed boiled yolk. Food efficiency and somatic growth were compared between larvae that were fed freshwater water fleas and those fed a micro-diet developed for flounder ($250{\mu}m$, I-hwa Ltd.). The number of rotifers ingested by larvae reached a maximum of 191 per day. However, based on the number ingested per hour and the digestive velocity of consumed rotifers, the maximum ingestible and digestible number of rotifers was calculated to be 272 per day. A maximum of 67 individuals (mean, 49.8 individuals) could be completely digested within the 1-h period from 90 to 180 min after feeding. Somatic growth was enhanced in larvae that were fed rotifers compared to those fed boiled yolk. Larvae exhibited greater growth at rotifer densities of 30 and 40 per mL than at lower densities. Among the water-flea (M. macrocopa and Bosmina sp.) and micro-particle diets, feeding with M. macrocopa resulted in the greatest somatic growth of larvae during the water-flea feeding stage.

• Journal of Microbiology and Biotechnology
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• v.21 no.10
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• pp.1073-1080
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• 2011

In order to investigate and generalize the effects of carbon and nitrogen sources on the growth of and lipid production in Chlorella sp. 227, several nutritional combinations consisting of different carbon and nitrogen sources and concentrations were given to the media for cultivation of Chlorella sp. 227, respectively. The growth rate and lipid content were affected largely by concentration rather than by sources. The maximum specific growth was negatively affected by low concentrations of carbon and nitrogen. There is a maximum allowable inorganic carbon concentration (less than 500~1,000 mM bicarbonate) in autotrophic culture, but the maximum lipid content per gram dry cell weight (g DCW) was little affected by the concentration of inorganic carbon within the concentration. The lipid content per g DCW was increased when the microalga was cultured with the addition of glucose and bicarbonate (mixotrophic) at a fixed nitrogen concentration and with the lowest nitrogen concentration (0.2 mM), relatively. Considering that lipid contents per g DCW increased in those conditions, it suggests that a high ratio of carbon to nitrogen in culture media promotes lipid accumulation in the cells. Interestingly, a significant increase of the oleic acid amount to total fatty acids was observed in those conditions. These results showed the possibility to induce lipid production of high quality and content per g DCW by modifying the cultivation conditions.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.519-522
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• 1997

Buffalo heifers weighing from 400 - 500 kg and having a history of reproductive problems like anestrus, irregular estrus or failure to conceive after repeated inseminations were administered subcutaneously with estradiol-$17{\beta}$ and progesterone in two dosage rate 0.1 mg and 0.25 mg, respectively, per kg body weight per day for 7 days in experiment-I and 0.1 mg and 0.125 mg, respectively, per kg body weight per day for 7 days in experiment II. In experiment-I, 9 out of 10 buffaloes responded positively to the hormonal treatment. Milk secretion started between 14-20 days after the start of the treatment. The total milk yield in the successfully induced animals varied from 471.98-625.40 kg. The average daily milk yield varied from 2.08-2.76 kg and peak yield from 3.6-5.3 kg. The time taken to reach peak yield varied from 12-14 weeks. In experiment - II, the established lactation response was absent, although milk secretion process was initiated, the yield could not reach more than 50 - 100 gm at each milking. In experiment - I, the first estrus occurred between days 87 - 231 following the hormonal treatment. Four animals in which lactation was established successfully got pregnant after one or two services. In experiment - II the first estrus occurred between 85 - 173 days following the treatment and only one animal got pregnant.

• Journal of Environmental Science International
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• v.25 no.10
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• pp.1381-1387
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• 2016

This study aims to establish baseline data for sustainable monitoring by applying the green city index (GCI), which is set up to evaluate the city level, to the city of Gangneung-si, which was designated as a pilot city for the Low-carbon Green Growth City project by the Ministry of Land, Infrastructure, and Transportation. The GCI was applied in the framework of European systems, while considering the social and economic status of Korea. Indicators from 7 areas-$CO_2$, energy, building, transportation, water, waste, and quality of atmosphere were analyzed, except for qualitative indicators. Results indicate that total $CO_2$ emissions were 30.8 tons per capita, or 2.2 tons per one million units of real GDP. The total final energy consumption was 0.231 TOE/capita, or 0.317 TOE per one million units of real GDP. The percentage of total energy derived from renewable resources was 0.41% and energy consumption by the building was $433.5Mwh/1,000m^2$. The total percentage of the working population travelling to work daily by public transportation (limited to bus) was 19%. Further, the total annual water consumption was $99m^3/capita$, and the water lost in the water distribution system was $0.057m^3/capita/day$. The total annual waste collected was 0.0077 ton per capita, The annual mean emission were 0.014 ppm/day for $NO_2$, 0.005 ppm/day for $SO_2$, and 0.019 ppm/day for $O_3$. The annual mean for PM10 emissions was $39{\mu}g/m^3/day$.

• Journal of radiological science and technology
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• v.4 no.1
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• pp.45-53
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• 1981

In examinations of the stomach roentgenography, it is imperative to obtain adequate film density throughout all its different regions. Therefore, it is necessary to use more sophiscated exposure techniques. In order to achieve these purpose, the radiologic technologists must be measured abdominal thickness in variations with patient positions. In consideration of these problem, the author was made an experiment on correction method of kVp and mAs by abdominal thickness in roentgenography of the stomach. The results were summarized as follws: 1. When the patient in erect position, abdominal thickness was the most thickened at the level of 3cm inferior to umbilicus without regard to body habitus and it was the most thickened at the level of 3cm superior to umbilicus in prone and supine position. 2. As a result of measuring film density for stomach, the adequate film density was represented from 0.70 to 2.49 in erect position and $0.28{\sim}1.18$ in supine position, $0.5{\sim}2.45$ in prone position. 3. In order to obtain uniform film density in 1.25, the correction factor for kVp by abdominal thickness was represented average ${\pm}4.5kVp\;per\;{\pm}1cm$ in a fixed 50 mAs, and average ${\pm}3.9kVp\;per\;{\pm}1cm$ in a fixed 100mAs. 4. In order to obtain uniform film density in 1.25, the correction factor for mAs by abdominal thickness was represented average ${\pm}30.9%\;per\;{\pm}1cm$ in a fixed 80 kvp and ${\pm}26.9%\;per\;{\pm}1cm$ in a fixed 100kVp.

• Progress in Medical Physics
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• v.31 no.4
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• pp.145-152
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• 2020

Purpose: In ionization-chamber dosimetry for high-dose-rate electron beams-above 20 mGy/pulse-the ion-recombination correction methods recommended by the International Atomic Energy Agency (IAEA) and the American Association of Physicists in Medicine (AAPM) are not appropriate, because they overestimate the correction factor. In this study, we suggest a practical ion-recombination correction method, based on Boag's improved model, and apply it to reference dosimetry for electron beams of about 100 mGy/pulse generated from an electron linear accelerator (LINAC). Methods: This study employed a theoretical model of the ion-collection efficiency developed by Boag and physical parameters used by Laitano et al. We recalculated the ion-recombination correction factors using two-voltage analysis and obtained an empirical fitting formula to represent the results. Next, we compared the calculated correction factors with published results for the same calculation conditions. Additionally, we performed dosimetry for electron beams from a 6 MeV electron LINAC using an Advanced Markus^® ionization chamber to determine the reference dose in water at the source-to-surface distance (SSD)=100 cm, using the correction factors obtained in this study. Results: The values of the correction factors obtained in this work are in good agreement with the published data. The measured dose-per-pulse for electron beams at the depth of maximum dose for SSD=100 cm was 115 mGy/pulse, with a standard uncertainty of 2.4%. In contrast, the k_s values determined using the IAEA and AAPM methods are, respectively, 8.9% and 8.2% higher than our results. Conclusions: The new method based on Boag's improved model provides a practical method of determining the ion-recombination correction factors for high dose-per-pulse radiation beams up to about 120 mGy/pulse. This method can be applied to electron beams with even higher dose-per-pulse, subject to independent verification.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.54-58
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• 1992

In order to determine the optimum planting density of Sickle Senna (Cassia tora L.), agronomic characters, yield components and grain yield were investigated under vinyl mulching and non -mulching condition. The characters, stem length, stem diameter, number of branches, number of pods per plant, number of pods per m$^2$, and number of grains per pod, etc., were excellent under the vinyl mulching condition, and number of pods per m$^2$ was the highest in 60$\times$15cm planting space under vinyl mulching or non-mulching. Both of the weight of 100 grains and grain yield were also higher under the vinylmulching condition, and grain yield was the most excellent in 60$\times$15cm planting space under the vinlymulching, or non-mulching. Under the vinyl mulching and non-mulching, the analysis of variance for agronomic characters following the difference of planting density, were acknowledged to be worth of attention.