• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.577-584
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• 2018

This study was conducted to investigate the potential of chicken feather (CF), which is a by-product in poultry industry, as a partial substitute of wood fiber in the production of wood-based fiberboard. Keratin-type protein constituted the majority of CF, and its appearance did not differ from that of wood fiber. When the formaldehyde (HCHO) adsorptivities of CF compared by its pretreatment type, feather meal (FM), which was pretreated CF with high temperature and pressure and then grounded, showed the highest HCHO adsorptivity. In addition, there was no difference between the adsorbed HCHO amounts, which was measured by dinitrophenylhydrazine method, of scissors-chopped CF and CF beated with an electrical blender. Mechanical properties and HCHO emission of medium-density fiberboards (MDF), which were fabricated with wood fiber and 5 wt% CF, beated CF or FM based on the oven-dried weight of wood fiber, were not influenced by the pretreatment type of CF. However, when the values compared with those of MDF made with just wood fiber, thickness swelling and HCHO emission of the MDF were improved greatly with the addition of CF, beated CF or FM. Based on the results, it might be possible to produce MDF with improved dimensional stability and low HCHO emission if CF, beated CF or FM is added partially as a substitute of wood fiber in the manufacturing process of MDF produced with the conventional urea-formaldehyde resin of $E_1$ grade. However, the use of CF or FM in the production of MDF has a low economic feasibility at the current situation due to the securing difficulty and high cost of CF. In order to enhance the economic feasibility, it requires to use CF produced at small to medium-sized chicken meat plants. More importantly, it is considered that the technology developed from this research has a great potential to make provision for the prohibition of animal-based feed and to dispose environmentally avian influenza-infected poultry.

• Journal of the Korean School Mathematics Society
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• v.21 no.4
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• pp.419-443
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• 2018

The purpose of this study was to analyze the problem solving strategies of ordinary students, gifted students, pre-service teachers, and in-service teachers with the 'chicken and pig problem,' which has multiple strategies to obtain the solution. For this study, 98 students in the 6th grade elementary schools, 96 gifted students in a gifted institution, 72 pre-service teachers, and 60 in-service teachers were selected. The researcher presented the "chicken and pig" problem and requested them the solution strategies as many as possible for 30 minutes in a free atmosphere. As a result of the study, the gifted students used relatively various and efficient strategies compared to the ordinary students, and there was a difference in the most used strategies among the groups. In addition, the percentage of respondents who suggested four or more strategies was 1% for the ordinary students, 54% for the gifted students, 42% for the pre-service teachers, and 43% for the in-service teachers. As suggestions, the researcher asserted that various kinds of high-quality mathematical problems and solving experiences should be provided to students and teachers and have students develop multi-strategy problems. As a follow-up study, the researcher suggested that multi-strategy mathematical problems should be applied to classroom teaching in a collaborative learning environment and reflected them in teacher training program.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.662-674
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• 2008

The purpose of this study was to investigate the patterns of fast food intake in residential areas and its relation to eating habits among 551 6th grade students (286 male students and 265 female students) from elementary schools located in Gangnam-gu, Dongjak-gu and Seongbuk-gu, Seoul. The results of this study were as follows. 1) There were significant differences in the preference for fast food among districts (p<0.05) and children from Seongbuk-gu showed a greater preference for fast food than those from Gangnam-gu and Dongjak-gu. In terms of preferences for particular types of fast food, children from Seongbuk-gu liked hamburgers more than those from Gangnam-gu and Dongjak-gu so that there were significant differences among districts (p<0.05). With regards to the frequency of intake of the various types of fast food, there were differences in hamburger, pizza and chicken among three districts (p<0.05) and children from Seongbuk-gu ate fast food 1 to significant 2 times more often than those from Gangnam-gu and Dongjak-gu. 2) There were significant differences in the regularity of mealtimes between districts (p<0.05), with children from Seongbuk-gu showing more irregularity in their mealtimes than those from Gangnam-gu and Dongjak-gu. There were significant differences in the frequency of snack intake (p<0.05), and children from Seongbuk-gu tended to take a snack 1 to 2 times more often than those from Gangnam-gu and Dongjak-gu. 3) In the frequency of fast food intake in accordance with obesity, there were significant differences between the obesity index (p<0.05). In particular, children who were underweight had a tendency to eat more fast food. There were significant differences between the frequency of fast food intake depending on children's pocket money (p<0.05), and children who took fast food more than twice a week tended to have more pocket money. According to these results, we report there are partly different trends in the consumption of fast food and food habits among the districts in Seoul. Therefore we suggest that different interventions be implemented within the different districts to reduce reliance on fast food restaurants and to address the perceptions of healthy eating as well as time and convenience barriers.

• Journal of Nutrition and Health
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• v.40 no.6
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• pp.531-541
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• 2007

This study was conducted to determine factors affecting detection threshold and the optimally-preferred concentration for sweet taste, since investigation into factors decreasing sensitivity or increasing preference for sweet taste is important to prevent overconsumption of simple sugar. Subjects were 70 first-grade middle school students in the Gyeonggi-Do. The detection threshold concentration of sucrose solution and the optimally-preferred sucrose concentration of omija jelly were determined by sensory evaluation. A self-administered questionnaire was used to obtain the information regarding health-related lifestyle practices, dietary habits, preference for and eating frequency of Westernized foods and frequencies of eating foods other than home-made. The detection threshold concentration of sucrose solution and the optimally-preferred sucrose concentration of omija jelly of the subjects were 0.204% and 14.44%, respectively. Subjects who exercise less (< 30 minutes/week except PE class), skipping meals (${\geq}$ 3/week), type of breakfast rather than traditional Korean meal and frequent eating out and buying foods from school tuck-shop tended to have higher sweet taste threshold. There was significant positive correlation between the sucrose threshold concentration and fried chicken preference or eating frequency of hamburger. Those who exercise less (< 30 minutes/week except PE class) did have significantly higher optimally-preferred sweetness of omija jelly, which tended to be higher in the subjects who had more (${\geq}$ 4 out of 10) behavioral or psychological stress symptoms and who had early getting-up time (before 7 am). There was significant positive correlations between the optimally-preferred sweetness of omija jelly and pizza preference, instant noodle eating frequency or sum of eating frequencies of five fast foods. From the results of this study, it was suggested that middle school students should make efforts to stop skipping meals, exercise more, eat Korean traditional breakfast and reduce the frequencies of eating out and using instant/fast foods in order to prevent overconsumption simple sugar.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.1
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• pp.42-47
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• 2006

This study was conducted to investigate the efficacy of surface spraying of antimicrobial solutions, oil and application of both on performance of broiler chicken under heat stress and reared on leaves and ground corn cobs as two alternative bedding materials. Six hundred seventy five day-old straightrun Arian broiler chicks were randomly assigned to 45 pens (at density of $0.09m^2/bird$) in an open sided partially-controlled shed. Three bedding materials viz. wood shavings (WS), ground corn cobs (GCC) (1.5 cm in length) and leaves were subjected to surface spraying of oil ($0.4L/m^2$ animal food grade sunflower oil), anti microbial solutions (3%) and mix treatment of both. Data on performance traits, incidence of breast and food pad lesions and litter characteristics were gathered and analysed in an appropriate factorial arrangements. Body weight at 56 d, feed intake up to 14 d, litter moisture at 28 d, litter pH at 14 d and litter temperature at 14 and 56 d were significantly influenced by litter type (p<0.05). Litter treatment revealed significant impact on body weight at 28, 42 and 56 d, feed intake during 29-42 and 1-42 d, mortality up to 56 d, litter temperature at 28 and 56 d, and litter pH at 28 and 56 d. Leaves and ground corn cobs have shown good potential as alternative bedding materials for rearing broilers. Surface spraying of antimicrobial solutions, oil and applying both were not effective tools to promote the broiler's health and performance. Meat type poultry growers and integrators are considered as primary audiences of the results achieved.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.6
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• pp.332-342
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• 2019

Objectives: Socket grafting is vital to prevent bone resorption after tooth extraction. Several techniques to prevent resorption have been described, and various bone graft substitutes have been developed and used with varying success. We conducted this pilot study to evaluate the performance of nanohydroxyapatite (nHA) derived from chicken eggshells in socket preservation. Materials and Methods: This was a prospective, single center, outcome assessor-blinded evaluation of 23 sockets (11 patients) grafted with nHA and covered with platelet-rich fibrin (PRF) membrane as a barrier. Bone width and radiographic bone density were measured using digital radiographs at 1, 12, and 24 weeks post-procedure. Postoperative histomorphometric and micro-computed tomography (CT) evaluation were performed. The study protocol was approved by the Institutional Ethics Committee. Results: All patients had uneventful wound healing without graft material displacement or leaching despite partial exposure of the grafted socket. Tissue re-epithelialized with thick gingival biotype (>3 mm). Width of the bone was maintained and radiographic density increased significantly with a trabecular pattern (73.91% of sockets) within 12 weeks. Histomorphometric analysis showed 56.52% Grade 3 bone formation and micro-CT analysis revealed newly formed bone with interconnecting trabeculae. Conclusion: Use of a PRF membrane with nHA resulted in good bone regeneration in sockets. Use of a PRF membrane prevents periosteal-releasing incisions for primary closure, thereby facilitating the preservation of keratinized mucosa and gingival architecture. This technique, which uses eggshell-derived nHA and PRF membrane from the patient's own blood, is innovative and is free of disease transfer risks. nHA is a promising economic bone graft substitute for bone regeneration and reconstruction because of the abundant availability of eggshell waste as a raw material.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.361-368
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• 2019

The objective of the current study was to determine calcium (Ca) and phosphorus (P) utilization in 4 different hatchery by-products (HBPs) for broiler chickens. The four different HBPs included infertile eggs (IFE), unhatched eggs (UHE), low grade and dead chicks (LDC), and a mixture (MIX) of 55% IFE, 10% UHE, and 10% LDC with 25% hatched eggshells. A total of sixty four 50-day-old Ross 308 broiler chickens were randomly allotted to 1 of 4 dietary treatments with 8 replicates per treatment. Two birds were placed together in one metabolic cage. Additional 16 birds were used to measure the endogenous losses of Ca and P. A forcefeeding procedure (i.e., crop intubation) was used to measure the apparent and true total tract retention (ATTR and TTTR, respectively) of Ca and P in the 4 HBPs. The results showed that the TTTR of Ca in the UHE was less (p < 0.05) than that in the IFE, LDC, and MIX. The amounts of available Ca in the MIX were greater (p < 0.05) than those in the IFE and UHE, which were greater (p < 0.05) than those in the LDC. The TTTR of P was not different among the 4 HBPs. However, the amounts of available P in the LDC were greater (p < 0.05) than those in the IFE and UHE, which were greater (p < 0.05) than those in the MIX. In conclusion, HBPs contain high amounts of available Ca and P because of high concentrations of total Ca and P with a high utilization rate. Therefore, the use of HBPs in broiler diets can reduce costs on Ca and P supplements.

• Korean journal of food and cookery science
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• v.26 no.6
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• pp.685-698
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• 2010

Acrolein is a highly toxic, reactive mutagenic aldehyde. Humans are exposed to acrolein vapors from overheated cooking oil, cigarette smoke, and combustion of organic products. In this study, we investigated elementary and middle school students' consumption of foods cooked at high heat, such as fried, direct fire, and indirect fire cooked foods. The subjects of this survey study were 265 fifth grade students and 396 middle school students nationwide. According to the results of the frequency test, broiled fish was the most frequently consumed, followed by fried fish, indirect cooked samgyebsal, and other fried foods, which were eaten more than three times per month. The total intake of foods cooked at high heat per child over 1 year was in the following order: Fried chicken(7.50 kg) > Samgeybsal(6.57 kg) > Broiled pork ribs(4.18 kg) > Broiled fish(4.12 kg) > Bulgogi(3.31 kg) > Fried dish(3.18 kg) > Pork cuttlet(3.17 kg) > Jeyukbockeum(3.13 kg) > Charcoal-broiled beef ribs(2.74 kg) > Roasted whole chicken(2.05 kg) > Dackochi(1.87 kg) > Tangsuyuk(1.87 kg) > Fried fish(1.83 kg) > Hamburger patties(1.21 kg) > Fried potato(1.01 kg) > Barbecue(0.95 kg) > Doughnut(0.80 kg) > Corn dog(0.66 kg) > Croquette(0.51 kg). The favorite cooking method was indirect fire cooking for beef, pork, and fish, whereas frying was preferred for chicken. The results of this study provide important data for assessment of acrolein exposure via foods cooked at high heat temperature. The results also indicate that children might be exposed to acrolein through consumption of foods cooked at high heat temperature, suggesting the need to promote education of proper food consumption behavior.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.382-387
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activity of sodium phytate (SPT) against Salmonella typhimurium in tryptic soy broth with different pHs and in chicken, pork and beef. In tryptic soy broth, SPT at the concentrations of 0.1, 0.5, and 1.0% effectively inhibited the growth of Salmonella typhymurium in a concentration-dependent manner. At pH 5.5-7.0 similar to meat pHs, 1% SPT almost completely inhibited the bacterial growth. The inhibitory effect of SPT was stronger at pH 7.0 than pH 5.5. In chicken, pork, and beef, SPT at the concentrations of 0.1, 0.5, and 1% significantly inhibited the growth of Salmonella typhimurium in a dose-dependant manner (p<0.01). The addition of 1% SPT in the meats significantly increased the meat pHs. These results indicate that SPT is very effective for inhibition of bacterial growth as a muscle food additive for increasing food safety and functions.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.183-193
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• 2012

This study was conducted to investigate the effect of feeding the electrolytic materials on blood and carcass traits of broiler during transportation exposed under intense heat condition in summer. The broilers were selected on the day when the outside temperature was about $32^{\circ}C$ to provide heat stressed environment. Broilers reared for 33 d were selected and fed with the electrolytic materials ($NaHCO_3$, NaCl, KCl) for 2 days. Treatments were as follows; feeding the underground water for control, $NaHCO_3$ (1.0%) + NaCl (0.5%) for treament 1, KCl (0.5%) + NaCl (0.5%) for treatment 2, KCl (1.0%) + NaCl (0.5%) treatment 3, KCl (0.5%) + $NaHCO_3$ (1.0%) + NaCl (0.5%) for treatment 4 and KCl (1.0%) + $NaHCO_3$ (1.0%) + NaCl (0.5%) for treament 5. pH of chicken meat increased for treatments group of electrolytic material, especially, that of treatment 3 was highest when compared to the other treatments. The frequency rate (%) of $1^+$ quality grade were 33.3, 60.0 and 83.3% at control, treatment 3, 4 and treatment 5, respectively. Occurrence rates of PSE were 50% for control and 13.3% for treatment 5. Corticosterone increased at the post-harvest period compared to the pre-harvest period of broiler and have small disparity between pre-and post-harvest only except treatment 3 when compared to control. $pCO_2$ partial pressure of blood at the pre-harvest period was low in all treatments by heat stress, the disparity value of control was high for control, and those of treatment 4 and 5 were low compared to other treatments.