• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.167-172
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• 2015

The aim of this study was to develop an effective production system of blueberry plants by using tissue culture technique. Murashige and skoog medium (MS) and woody plant medium (WPM) were compared for shoot formation of highbush blueberries. Also medium supplemented with zeatin/2-isopentenyl adenine (2iP)/benzyl aminopurine (BA) (1, 2/10, 15/4, $6mg{\cdot}L^{-1}$)and zeatin/2iP/BA (0.5/10, 15/$0.05mg{\cdot}L^{-1}$) as plant growth regulators to determine the effect of shoot formation and shoot proliferation, respectively. The shoot explants cultured on WPM showed higher shoot formation rates, more number of nodes, and longer root length than those on MS medium during the primary culture. Shoots were not formed when the explants were cultured on the medium without plant growth regulators or on only BA. The shoot explants cultured on the medium supplemented with 2iP showed low rates of shoot formation. On the other hand, zeatin was the most effective for shoot formation and growth of the explants. Also influence of different cytokinins (zeatin, 2iP) on the shoot proliferation of subcultured shoot explants was studied. There was no significant difference among the different concentrations of zeatin in the rate of shoot formation and number of shoots. However at higher concentration of zeatin, number of nodes was increased, and shoot length was shorted. The proper concentrations of zeatin for shoot propagation in subculture were found to be $0.5mg{\cdot}L^{-1}$ and $1mg{\cdot}L^{-1}$.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.525-535
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• 2017

In order to produce hydrophilic coating solution, which has superior antifogging and antifouling effect on the glass surface of solar cell module as well as improving photovoltaic efficiency, nanosilica was dispersed in an aqueous solution of Tween 20 and fluorosurfactant composed of decafluorobutane and polyethylene glycol. The antifogging effect at high temperature was excellent for all the coating solutions containing nanosilica, but the antifouling effect was observed when the content of nanosilica was over 6 wt%. As the content of fluorosurfactant increased, the initial water contact angle slightly increased and the antifogging effect remained well until 500 wiping with wet $Wipeol^{(R)}$. The antifouling effect was also excellent regardless of the content of fluorosurfactant, thus 0.1 wt% of the fluorosurfactant was enough for a coating solution production. From the AFM results, when 0.1 wt% to 0.3 wt% of the fluoro surfactant was added, the fractal structure of the coated glass surface was clearly existed and contributed to the better antifouling effect. The transmittance of coated glass surface was highest in TL-1 coating solution containing 0.1 wt% of fluorosurfactant, and the addition of fluorosurfactant in a larger amount than 0.1 wt% did not improve the transmittance. This result is in good agreement with the previous AFM result which shows a high surface roughness as well as a fractal structure formation for the TL-1 coating solution.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.35-40
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• 2016

Recently, bacterial angular leaf spot disease, caused by Xanthomonas fragariae, causes severe damage in strawberry production and its' export to other countries, since the pathogen has been classified as an A2 quarantine pathogen. Typical the Angular Leaf Spot (ALS) disease represent that water-soaked angular spots symptoms, bacteria ooze exudate under relatively high humidity condition and later the spot become reddish brown on the leaf surface. The pathogen disseminated by irrigation water, infected mother plant and farmer's hand. In this study, we reported that rubbing inoculation method showed more effective in the pathogen dissemination than infiltration with needles, regardless the strawberry cultivars. Additionally, Dichloroisocyanurate (NaDCC) treatment in commercial strawberry fields provided reliable efficiency to reduce the bacterial angular leaf spot disease incidency and severity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.184-189
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• 2018

Recently, research on lightweight automobiles is increasing continuously to respond to the high safety standards and environmental regulations. The application of high strength steel is one of the effective methods for developing lightweight car bodies. A TWB (Tailor Welded Blank) is major method that allows partial high strength with light weighting using a multi-thickness and multi-material welded blank. On the other hand, additional welding process is required to prepare the blank and quality control for the welding process also required. To secure this point, the TRB (Tailor Rolled Blank) method was suggested. In the TRB method, the thickness of sheet is controlled by the rolling presses and the production efficiency is much higher than welding in TWB methods. In this study, the formability of high strength TRB steel plate was analyzed to examine the rolling effect of the blank. The formability of the specimen was tested using 0.8 and 1 mm thick steel sheets for the TRB plate. The strain was analyzed by the digital image sensing of grid markings on the specimen and the forming limit diagram was calculated. An Erichsen test for the 0.8 and 1 mm thick TRB specimens was carried out and the formability was investigated by comparing with FE analysis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.595-602
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• 2017

In Korea, much research and development have occurred to enhance the technological competitiveness of tuna purse seining fisheries. Due to these efforts, fishing efficiency has been improved with the development of radar, sonar and global positioning systems for fish detection and revisions to the hull forms of tuna purse seiners. However, for skiff boats, net boats and speed boats, which are auxiliary working boats mounted on tuna purse seiners, technology has lagged behind relative to the modernization of the main vessel. In this study, the hull of an existing propeller-based net boat with steel wire net to protect tuna was changed to the hull of a water jet propulsion vehicle to reduce resistance and improve maneuverability. As a result, a prototype of a water jet propulsion option was produced according to the aluminum structure strength standards specified by the Ministry of Oceans and Fisheries, and safety was confirmed by performing a drop test. Moreover, through a sea trial test, an existing net boat was shown to have a speed of 12.0knots and a towing force of 2,545 kgf at 2,500 RPM. The prototype had a speed of 26.7 knots and a towing force of 2,011 kgf at 3,200 RPM, which satisfied the towing capacity standards of auxiliary working boats mounted on tuna purse seiners.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.962-970
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• 2007

A total of 1,200 LinNan Chinese color-feathered chicks were used to study the effects of methionine source [DL-2-hydroxy-4-methylthio-butanoic acid (HMTBa) or DL-methionine (DLM)] and dietary crude protein (CP) level on growth performance, carcass traits, and whole-body nitrogen and fat retention. The trial was designed as a $2{\times}2$ factorial arrangement, including two CP levels (adequate and low) and two methionine sources (HMTBa and DL-methionine). Diets were formulated for three phases, starter (0-21 d), grower (21-42 d), and finisher (42-63 d). Chicks fed HMTBa had higher daily gain and improved feed efficiency than DLM during the grower phase (p<0.05). A significant two-way interaction was observed for growth performance during the finisher phase and overall (0-63 d). Growth performance was greater for chicks fed HMTBa than DLM on adequate-CP diets (p<0.05), but this was not observed at low-CP level (p>0.05). Chicks fed low-CP diets grew slower, used feed less efficiently during the grower, finisher phase and overall. On d 42, regardless of dietary CP levels, birds fed HMTBa had higher carcass weights, breast and thigh weights than DLM-fed birds (p<0.04). Birds fed low-CP diet had lighter carcass weights and less breast muscle, thigh muscle, and dressing percentage at the end of starter, grower and finisher phases (p<0.05). Whole body composition analyses found that birds fed HMTBa tended to contain more protein and less fat compared to those chicks fed DLM at the end of the starter phase (p<0.10). Low-CP diets increased CP concentration in the whole body at the end of the finisher phase (p = 0.05). HMTBa supplementation increased whole-body N retention rate during the finisher phase and overall (p<0.01), and low-CP diets reduced N intake and whole-body fat retention during the finisher phase and overall (p<0.05). In summary, HMTBa was better than DLM on an equimolar basis for growth performance, carcass traits, and N retention in Chinese color-feathered chicks. Low-CP diets lowered growth performance as well as carcass traits in color-feathered birds, probably due to imbalanced AA profiles.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.198-203
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• 2008

This study was conducted to compare the effects of feeding high protein and low energy milk replacer (HPR; CP 25%, ME 3.6 Mcal/kg DM) with low protein and high energy milk replacer (HPR; CP 21%, ME 4.2 Mcal/kg DM) on feed consumption, body weight (BW) gain, health and selected blood metabolites in Holstein calves during the pre-weaning period. At each feeding, each milk replacer (MR) was prepared by mixing 0.125 kg of dry MR in 1L of warm ($60^{\circ}C$) water. The calves were fed either HPR (n = 10) or HER (n = 10) using mobile plastic bottles fitted with soft rubber nipples. All calves received 1.8L diluted MR at each feeding 3 times daily during the first 4 weeks of age; feeding frequency was reduced to 2 times daily for the next 2 weeks of age and then to once daily during the last week of the experiment. Jugular blood was sampled in calves at day 7, 14, 21, 35 and 49 of age to enumerate selected metabolites. Daily MR, starter and hay intake during the pre-weaning period were similar in calves fed HPR and HER. Consumption of starter, MGH and total DM steadily increased with the age of calves. Final BW, daily BW gain and feed efficiency of calves were not affected by treatments. Serum glucose, cholesterol, creatinine were decreased (p<0.05) and blood urea N was increased (p<0.05) in calves fed HER or HPR as they grew older. Serum glucose, total protein and albumin concentrations in calves were not affected by treatments. Serum GPT and GOT concentrations were higher (p<0.05) in calves on HPR than on HER. Scouring score, days scoured, respiratory score, rectal temperature and general appearance were similar in calves fed HPR and HER. Poor general appearance (dullness and droopy ears) of calves fed either HPR or HER reflected nutritional insufficiency and stress. In conclusion, energy and protein concentrations in MR did not affect feed intake and BW gain in Holstein calves during the pre-weaning period. Poor general appearance and lower BW gain of calves compared to those reported in the literature for milk fed calves prompt a demand for further research to improve the daily nutrient supply to MR-fed calves.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.371-377
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• 2009

The objectives of the present study were to investigate the effects of different dietary ratios of whole-crop corn silage and alfalfa hay on nitrogen (N) digestion, duodenal flow and metabolism across the portal-drained viscera (PDV) of growing beef steers, and to elucidate their relationships. Four steers (236${\pm}$7 kg BW) fitted with duodenal cannulae and chronic indwelling catheters into the portal and mesenteric veins and abdominal aorta were used in a 4${\times}$4 Latin square design. Animals were fed (at 12-h intervals) the 4 diets consisting of whole-crop corn silage (C) and alfalfa hay (A) in 80:20 (C8A2), 60:40 (C6A4), 40:60 (C4A6) and 20:80 (C2A8) ratios of which dietary crude protein (CP) was 10.5, 12.0, 13.5 and 15.0% of dry matter (DM), respectively. Feeding level was restricted to 95% of ad libitum intake to measure N digestion, blood flow and net flux of N across the PDV. Digestibility of DM and neutral detergent fiber and digestible energy intake linearly increased as the ratio of alfalfa hay increased. The N intake, duodenal flow and intestinal disappearance increased linearly with increasing alfalfa hay. Arterial and portal concentrations of ${\alpha}$-amino N showed a quadratic response to increasing levels of alfalfa hay and were the highest in steers fed the C6A4 diet. The net PDV release of ${\alpha}$-amino N and ammonia N increased linearly with increasing alfalfa hay, but urea N uptake by PDV did not differ among diets. As a percentage of apparently digested N in the total gut, net PDV release of ${\alpha}$-amino N linearly decreased from 66 to 48% with increasing alfalfa hay. Conversely, net PDV recovery of ${\alpha}$-amino N to intestinal N disappearance varied with increasing alfalfa hay accounting for 49, 50, 58 and 61% on C8A2, C6A4, C4A6 and C2A8 diets, respectively. Net PDV uptake of urea N, relative to apparently digested N, linearly decreased from 81 to 25% as alfalfa hay increased from 20 to 80% of DM intake. Considering PDV uptake of urea N, microbial efficiency and conversion of total tract digested N to PDV ${\alpha}$-amino N net supply, a diet consisting of 80% whole-crop corn silage and 20% alfalfa hay (10.5% CP) was the best, while considering the quantities of intestinal N disappearance and ${\alpha}$-amino N absorption, a diet of 20% whole-crop corn silage and 80% alfalfa hay (15% CP) would be preferred. The proportion of ${\alpha}$-amino N recovered by PDV relative to the intestinal N disappearance may vary with energy intake level of mixed forage diets.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.213-223
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• 2012

In this study, two experiments were conducted to evaluate the total mixed ration with fermented feed (TMRF) and total mixed ration (TMR) by rumen in vitro fermentation and their effects on the growth performance and blood characteristics of Hanwoo steers. In experiment 1, three Hanwoo steers ($600{\pm}47$ kg), each permanently fitted with a ruminal cannula were used. In this experiment, three diets designated as T1, TMRF (18.4% fermented feed, tall fescue, mammoth wild rye forage and whole crop barley); T2, TMRF (17.7% fermented feed, rice straw and whole crop barley); and T3, TMR (rice straw, whole crop barley and probiotics, but no fermented feed), which were subjected to rumen in vitro fermentation for 48 h. The results demonstrated that DM disappearance rate gradually increased with advancing fermentation time, but T1 and T2 were higher than the T3 (p<0.05) from 3 h to 12 h, but insignificant (p>0.05) at 24 and 48 h. None of the specific VFAs were affected except for acetic and non volatile lactic acids, which were produced more in T2 than in T1 and T3 at 24 h and 48 h of incubation. A/P was lower in T1 and T2 than inT3 at 24 h (p<0.05) and 48 h (p>0.05) of incubation. These results confirmed that TMRF-related treatment shows a superior performance to that of TMR during the ruminal fermentation period. In experiment 2, the three diets in experiment 1 plus 1 more control diet (concentrates, probiotics and 2% rice straw of body weight) were fed to the 48 Hanwoo steers ($160{\pm}10$ kg) for a period of 168 d. The results demonstrated that the daily and total live weight gain and feed efficiency were higher (p<0.05) in the TMRF and TMR groups than in the control group. SGOT, SGPT and BUN (p<0.05) were reduced in TMRF relative to the control and TMR groups by 168 d which confirmed that TMRF shows better blood profiles than the TMR and control groups. Overall, these results appear to show that TMRF has better in vitro ruminal characteristics than those of TMR; growth performance and blood profiles were also found to be superior in TMRF than in the TMR and control groups. Thus, our findings suggest that TMRF-based feed supplies are favorable for Hanwoo cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.267-271
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• 2012

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol ($1{\alpha}$-OH $D_3$) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of $1{\alpha}$-OH $D_3$ (0, 5, and 10 ${\mu}g$/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin $D_3$. As a result of this study, the addition of $1{\alpha}$-OH $D_3$ increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary $1{\alpha}$-OH $D_3$ enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, $1{\alpha}$-OH $D_3$ decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the $1{\alpha}$-OH $D_3$ improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.