• Animal Bioscience
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• v.36 no.1
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• pp.84-97
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• 2023

Objective: One hundred hybrid male ducks (Mojosari×Alabio) were used to examine the efficacy of chicory supplementation as nutritional feed manipulation on production performance, and blood lipid profile of hybrid ducks. Methods: The ducks were tagged, weighed, and then allotted randomly to one of the four treatment diets using a completely randomized design. The experimental diets were: i) P0 (100% basal diets+0% chicory as control), ii) P1 (95% basal diets+5% chicory), iii) P2 (90% basal diets+10% chicory) and iv) P3 (85% basal diets+15% chicory). For each treatment group, there were 5 replicates of 5 birds each. All experimental diets were isonitrogenous and isocaloric using locally available ingredients. Results: Hybrid ducks with fed diets supplemented fresh chicory (5%, 10%, and 15%) showed increased feed intake and body weight gain, as well as feed conversion ratio to be smaller than those ducks fed diets without chicory supplementation (control). The ducks fed 10% chicory supplementation contained significantly (p<0.05) lower ash and higher organic matter contents of meat than those ducks fed other diets. The ducks fed 15% chicory supplementation showed the lowest crude protein and cholesterol content of meat among the treatment diets. Ducks fed chicory supplementation showed lower (p<0.05) blood cholesterol and triglyceride levels than those ducks fed without chicory supplementation, while dietary interventions had no major (p>0.05) influence on low-density lipoprotein and high-density lipoprotein levels in duck blood. Conclusion: In this study, 10% chicory supplementation showed the best results characterized by an increase in growth performance, carcass quality, small intestinal histomorphology, and lower cholesterol levels of meat.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.109-115
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• 2022

The demand for metal 3D printing technology is increasing in various industries. The materials commonly used for metal 3D printing include aluminum alloys, titanium alloys, and stainless steel. In particular, for applications in the aviation and defense industry, aluminum alloy 3D printing parts are being produced. To improve the corrosion resistance in the 3D printed aluminum alloy outputs, a post-treatment process, such as chromate coating, should be applied. However, powdered materials, such as AlSi7Mg and AlSi10Mg, used for 3D printing, have a high silicon content; therefore, a suitable pretreatment is required for chromate coating. In the desmut step of the pretreatment process, the chromate coating can be formed only when a smut composed of silicon compounds or oxides is effectively removed. In this study, suitable desmut solutions for 3D printed AlSi7Mg and AlSi10Mg materials with high silicon contents were presented, and the chromate coating properties were studied accordingly. The smut removal effect was confirmed using an aqueous desmut solution composed of sulfuric, nitric, and hydrofluoric acids. Thus, a chromate coating was successfully formed. The surfaces of the aluminum alloys after desmut and chromate coating were analyzed using SEM and EDS.

• Journal of Adhesion and Interface
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• v.23 no.4
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• pp.130-136
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• 2022

Recently, organic semiconductor based indoor photovoltaics have gained attention since they exhibit excellent photovoltaic performance than that of conventional Si-based photovoltaics. In this study, we synthesize the medium bandgap polymer of PTBT and optimize PTBT:PC₇₁BM blend films by introducing solvent additives. To this end, we select DIO and CN solvent additives and vary their contents from 0 to 3 vol%. As a result, we produce the highest power conversion efficiency of 11.31% under LED 1000 lx conditions with DIO (1.5 vol%) + CN (0.5 vol%)

• Animal Bioscience
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• v.36 no.7
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• pp.1075-1082
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• 2023

Objective: Animal feed companies and researchers are currently embarking on quests for feed additives that could combat the pathogens while promoting growth as well as maintaining quality products. The current study aimed to evaluate the effects of onion extracts on growth performance, carcass quality, and bone morphometrics of broiler chickens. Methods: A total number of 200 one-day-old unsexed Ross 308 broiler chicks were assigned to 5 treatment groups, replicated 4 times. Each replicate (pens) held 10 chickens in a completely randomized design. The experimental diets were then randomly allotted to the pens which act as experimental units. The isoenergetic and isonitrogenous diets were formulated by including onion extracts at 0, 5, 10, 15, or 25 g/kg in a complete broiler diet. Feed intake, and body weight, were recorded then used to calculate feed conversion ratio. At the end of the experiment (42 days), four chickens from each pen were randomly selected for slaughter for carcass, bone morphology and sensory evaluation. Results: Results showed that onion extract supplementation did not affect (p>0.05) growth performances and meat sensory evaluation. However, there was a significantly increased (p<0.05) meat shear force in groups receiving onion extracts dietary treatments. Furthermore, onion extracts improved (p<0.05) bone morphology of broiler chickens in terms of weight, diameter, calcium, and phosphorous contents. Conclusion: In conclusion, onion extracts can be safely included in a commercial broiler diet as a growth promoter without causing adverse effects on growth performance traits and carcass quality in chickens. Onion extract supplementation improved tibia bone growth and strength in broiler chickens.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.804-817
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• 2023

This study was conducted to evaluate the effects of co-dried fish protein hydrolysate (CFPH) on broilers performance, intestinal microbiology, and cellular immune responses. Five hundred one-day-old (Ross 308) male broilers were allocated to four treatments with five replicates of 25 birds in a completely randomized design. The experimental treatments included four levels of CFPH (0% as the control, 2.5%, 5%, and 7.5%) in the isonitrogenous and isocaloric diets. During the experiment, body weight (BW) and feed intake (FI) were periodically recorded in addition to calculating average daily gain (ADG), feed conversion ratio (FCR), liveability index, and European broiler index (EBI). In addition, cellular immune responses were evaluated at 30 days of age. On day 42, ileal contents were obtained to examine the microbial population. Based on the findings, Dietary supplementation of 5 and 7.5% CFPH increased the percentage of the thigh while decreasing the relative weight of the gizzard compared to the control group. The highest relative length of jejunum was observed in birds receiving 2.5 and 5% CFPH, and its highest relative weight belonged to birds fed with 5% CFPH. The number of coliforms, enterobacters, and total gram-negative bacteria in the intestines of birds receiving CFPH was less than that of the control group. In general, the application of CFPH in broiler nutrition can decrease the level of soybean meal in diet and it can be considered as a new protein supplement in poultry production. It is suggested to study the incorporation of this new supplement in other livestock's diets.

• Journal of Korean Home Economics Education Association
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• v.35 no.3
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• pp.151-167
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• 2023

The advent of the carbon neutrality era has led to a paradigm shift in education toward ecological transition education. It is time to understand the concept and practice of ecological transition education pursued in the 2022 revised curriculum and prepare for changes to the main life education covered in home economics education. Therefore, the purpose of this study is to explore the role of home economics education for carbon neutrality for future generations who will have to live in the era of rapidly changing climate crisis, and to propose a practice plan for ecological transition education in the main living area based on the educational contents of the 2022 revised curriculum. To achieve these objectives, this study reviewed previous research on carbon neutrality and ecological transition education, analyzed the curriculum for main life from the first curriculum to the 2022 revised curriculum, and proposed the direction of main life education for ecological transition education. Through this study, the importance of carbon neutrality and ecological transition can be emphasized in home economics education, and it is expected that it can be used as a basis for realizing ecological transition education in actual education sites.

• Journal of Nutrition and Health
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• v.48 no.1
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• pp.113-121
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• 2015

Purpose: The purpose of this study was to investigate satisfaction with and perception of the school meal service according to middle school students and dieticians/dietetic teachers in Gwangju area who experienced change to the free meal service and the main contents were as follows. Methods: The research subjects were 197 students (99 boys and 98 girls) and 42 dieticians/dietetic teachers were recruited. Results: Compared to the free meal service before, satisfaction of students was high (53.8%), and 69.9% of students said there was no change in the school meals, however a significant difference was observed between gender. Overall 80.2% of middle school students said that there was no change in menu, 70.6% were no change in the frequency of food with high preference, and 64.0% were no change in leftover of meals. 85.7% of dieticians/dietetic teachers said that there was no change in the student's satisfaction according to the conversion of free meal services; 59.5% of dieticians/dietetic teachers said that there was no change in the frequency of foods with high preference, the variety of vegetables was increased in the qualitative change item of food materials, and 95% of them were not aware of change in the amount of students' leftover foods. Dieticians/dietetic teachers had limitations in selecting menus with purchase and costs of food materials (26.2%) by conversion of the free meal service and their priority considered was the food cost (45.2%) when they selected menus. Change in feeding affairs was office work management (26.2%) and recipe research and development (19.0%). Conclusion: With the results of this study, the satisfaction with the school meal service was not changed in the awareness of students and dieticians/dietetic teachers. Therefore further study is needed to determine the middle school's satisfaction with school meals based on a variety of factors including the environmental food meal services.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.351-359
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• 2010

To establish the optimum artificial light illumination method for baby leaf lettuce in closed plant factory system, the effects of red/blue light quality and short-term light quality conversion on growth and anthocyanin content were investigated. The growth of 'Hongha' lettuce was most favorable under red single wavelength LED light after 23 days of treatment, sequentially followed by the growth under red/blue mixed light, blue light, and fluorescent light. Total anthocyanin content in the mixed red/blue light (R57-B43) was 4.1-fold and 6.9-fold increased compared to the red LED and fluorescent light, respectively. With increasing the blue light ratio to 43%, the growth of lettuce was significantly decreased, while the relative chlorophyll content and Hunter's $a^*$ value was increased, indicating that the red/blue light ratio inversely affects on growth and anthocyanin pigment development. By changing light quality from red to red/blue mixed light source (R57-B43) for 9 days before harvest, the growth rate decreased compared to the continuous red light illumination, while the anthocyanin content dramatically increased compared to either red LED or fluorescent light. Whereas, when the light source was changed to red light, the growth rate was increased but anthocyanin content was reversely decreased. The result demonstrated that both growth and anthocyanin expression could be effectively regulated by shifting of light quality between red and red/blue mixed light source at a specific growth stage of lettuce in a plant factory.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.125-134
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• 2002

Two experiments were conducted to compare the dietary supplemental influence of conjugated linoleic acid(CLA), soybean oil(SBO) and commercial tallow(CT) on MEn, performance and breast meat composition of broiler chicks. Diets contained 21.5, 19% CP and 3,100, 3,100kcal/kg ME for starter and finisher, respectively. Each three levels(1.0, 2.0, 3.0%) of CLA, SBO, CT were supplemented to basal diets. Five hundred fDrty and three hundred sixty one day old, male broiler chicks were replaced to 3$\times$3, 2$\times$3 factorial design with four replicates in Expt 1 and 2. Weight gain, fled intake, fled conversion, W antibody titer and fatty acid composition were measured. Metabolizable energy(ME) were measured through the metabolic feeding trial in each oil. ME was 8,542, 9,179, 8,733 kcal/kg in CLA, SBO and CT, respectively. In Expt 1, weight gain was not statistically different between dietary oil treatments. Feed intake was significantly increased by CLA supplement(P<0.05). Feed conversion was significantly improved in SBO supplemental groups of all treatments(P<0.05). Weight gain and feed intake were significantly increased and fled conversion was significantly improved in CLA 2% and 3% supplemental groups compared with CLA 1% group(P<0.05). Fatty acid composition of breast meat was changed by CLA supplement. CLA content of breast meat was 12.23, 18.74, 25.67 mg/g in 1, 2, and 3% CLA treatments and showed significant difference between them(P<0.05). In Expt 2, CLA supplements increased weight gain signi(icantly for (inishing period(P<0.05) compared to that of other treatments. There was no significant difference in M Antibody titer in Expt 1 and Expt 2. As the results of these experiments, birds fed CLA tended to gain higher weight and significantly increased CLA contents of breast meat(P<0.05).

• Journal of Christian Education in Korea
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• v.78
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• pp.21-55
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• 2024

Purpose of study: The purpose of this study is to examine the crisis situation of Christian education experienced by Korean churches and theological education institutions after the COVID-19 pandemic, and to seek new tasks and directions that Korean churches should prepare for the recovery and growth of Christian education. Research Contents and Methods: Before reviewing the current crisis experienced by Korean churches and theological education institutions after the COVID-19 pandemic, the terms and concepts of Christian education are first reflected. In addition, the causes and phenomena of the Korean church and Christian education crisis after the COVID-19 Pandemic are examined through statistics, media, and church field data. The researcher identified the causes of the crisis experienced by Korean churches and theological education institutions as follows: 1. The influence of COVID-19 Pandemic: suspension of faith and educational activities, 2. The age of population cliffs: increase in the elderly vs. decrease in young people, 3. Neoliberalism: marketism, infinite competition, efficiency, winner-take-all, 4. post-religious era: post-Christianity, weakened communitarianism, and reduced number of Christians. The results of this study are four points as follows: 1. Crisis of church education: suspension of operation of Sunday school and feeling of failure, 2. Crisis of faith of young generation: nurturing unstable future church leaders, 3. Faith of adult generation: crisis and hope, 4. The faith of the elderly generation: light and shadow. Conclusion and Recommendations: The new task and direction of Christian education that Korean churches should pursue after the COVID-19 pandemic are as follows: 1. New conversion of Sunday school faith education: From schooling-paradigm education to faith education that integrates family and generation. 2. New conversion of theological education: From knowledge education to spirituality training. 3. Re-ignition of faith education for middle-aged adults: Activation of faith through worship and small groups, 4. New conversion of church elder education: The need to change from caring objects to creative religious life.