• Journal of The Korean Society of Grassland and Forage Science
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• 제41권4호
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• pp.267-272
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• 2021

This experiment was conducted to the purpose of evaluating the effect of feeding on Korean Native Cattle to expand the production and utilization of whole crop rice (WCR). TMR (Total mixed ration) feed was prepared by using WCR produced in Pyeongtaek, Gyeonggi-do, and the growth capacity and meat quality characteristics of 16 Korean Native Cattle raised up to 29 months of age were investigated. The produced WCR silage for feed had a moisture content of 64.02% and a crude protein content of 7.54%, and was blended with about 45% during the growing season, and lowered to 35, 15 and 9%, respectively, in the fattening period (early, middle and late stages). The body weight of the WCR-TMR feeding group was significantly higher than that of the control in the middle and late fattening stage, and at the end (29 months of age), the control group was 631 kg/head, but the WCR-TMR feeding group was 647 kg/head, which was higher. The average daily gain was significantly higher in the WCR-TMR feeding group in the growing and early fattening period, and there was no difference in the mid- and late fattening period. In the whole period, 0.71 vs 0.75 kg/head/day, WCR-TMR feeding group was high. In terms of meat quantity, the back fat thickness of the control group (11.7 mm) was significantly thicker than that of the WCR-TMR fed group (9.3 mm) (P<0.05). There was no difference in Rib eye area, Carcass weight and Meat yield index (P>0.05). In terms of meat quality, the Marbling score was higher in the WCR-TMR feeding group (P<0.05), and there were no significant differences in Meat color, Fat color, Texture and Maturity. Considering the above results, TMR feeding mainly on whole crop rice silage for feed improved the productivity of livestock, but there was no significant difference in meat quality. Therefore, it is judged that it is necessary to produce and use the whole crop rice for feed in countries with poor forage conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• 제42권2호
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• pp.79-88
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• 2022

This study was conducted to evaluate the productivity of whole crop silage wheat utilizing the paddy fields during a couple of years from 2019 to 2021 in Suwon, Korea. This investigation was used the two maturity types of wheat cultivar 'Cheongwoo' (early) and 'Taeu' (late). The heading date of 2^nd year (Oct. 2020 to May. 2021) cultivation was delayed about 11 to 13 days by more than 1^st year (Oct. 2019 to May. 2020). The growth characteristics were shown that the plant height was increased in 2^nd cultivation, while the number of culms and the panicle part ratio were decreased. Moreover, the nutritive value of 'Cheongwoo' and 'Taeu' were also decreased in 2^nd cultivation. These changes have thought to a difference of the precipitation by cultivation years. Because, the precipitation during the period from the end of winter dormancy to the harvesting stage in 2^nd (337 mm) cultivation was more about twice than 1st (169.3 mm) cultivation. However, the dry matter yield of 'Cheongwoo' was not shown a statistical difference by cultivation years, while 'Taeu' was shown to decrease tendency. The total dry matter yield regardless of the cultivation years were higher in 'Cheongwoo' than 'Taeu', and especially 'Cheongwoo' was more 3 tons per hectare (15.3 t/ha) than 'Taeu' (12.6 t/ha) at 2^nd cultivation (p<0.01). The trend of dry weight in 'Cheongwoo', early mature type, showed a relatively high ratio of dry matter (p<0.05) was considered that due to a high panicle ratio by a fast heading and an adequate weight of panicles by a sufficient maturing. In conclusion, selecting the early maturity cultivars could achieve a higher and more stable total dry matter yield considering the cropping system in the central region. Furthermore, it also has the advantage of being able to double-cropping system with forage rice, which has considered the maximum whole-crop forage production year-round. These results suggest that the 'Cheongwoo' be optimum cultivar to produce the year-round forage on paddy fields in the central region.

• Journal of The Korean Society of Grassland and Forage Science
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• 제42권2호
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• pp.73-78
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• 2022

This experiment was conducted to establish the technology for artificial hay preparation in Korea. Using far-infrared heater, a device that can control temperature, airflow, and far-infrared radiation was produced and conducted on the fourth harvested alfalfa. The drying conditions were carried out by selecting a total of four conditions. For each condition, the radiation rate was set to around 40% (33-42%), and the temperature was set at 58~65℃, and the speed of the airflow was fixed at 60m/s. The overall drying time was set to 30 min in the single and 60 min (30-30 min) and 90 min (30-30-30 min) in the complex condition, and the radiation rate and temperature were changed by time period. In the case of drying condition 1, the final dry matter (DM) content was 46.26%, which did not reach a DM suitable for hay. However, all of the alfalfa corresponding to the remaining drying conditions 2 to 7 showed a DM content of 80% or more, resulting in optimal alfalfa hay production. In power consumption according to the drying conditions, the second drying condition showed the lowest at 4.7 KW, and the remaining drying conditions were as high as 6.5 to 7.1 KW. The crude protein content was found to be high at an average of 25.91% and it showed the highest content in the 5th drying condition (26.93%) and the lowest value in the 6th drying condition (25.16%). The digestibility showed a high value with an average of 84.90%, and there was no significant difference among treatments (p>0.05). Considering the above results, it was judged that drying condition 2 was the most advantageous.

• The Journal of Korean Academy of Prosthodontics
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• 제60권3호
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• pp.231-238
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• 2022

Purpose. This study aimed to investigate the effect of different veneering methods on the tensile bond strength between polyetherketoneketone (PEKK) and denture base resins. Materials and methods. A total of 80 PEKK T-shaped specimens were fabricated and the primer (Visio.link) was applied after airborne-particle abrasion with 110 ㎛ alumina oxide powder. According to the veneering method, the specimens were divided into four groups (n = 20) to be veneered with the gingival colored packable photopolymerized composite resin (SR Adoro); flowable photopolymerized composite resin, (Crea.lign); heat-polymerized resin (Vertex); and self-polymerized resin (ProBase Cold). Each group was divided into two subgroups (n = 10) according to the artificial thermal aging. After the tensile bond strength measurement via universal testing machine, the fracture sections of all specimens were observed. Two-way ANOVA and Tukey's HSD post hoc test were used for the statistical analysis (α = .05). Results. The results of the two-way ANOVA showed statistically significant differences in the tensile bond strength according to the veneering method and artificial thermal aging of denture base resins (P<.001). The highest tensile bond strength showed in the packable photopolymerized resin group before and after the artificial thermal aging. The lowest tensile bond strength showed in the heat-polymerized resin group. The mixed and adhesive fracture showed in all groups. Conclusion. The veneering method and artificial thermal aging can influence in the tensile bond strength between the resin and PEKK. The artificial thermal aging can reduce the tensile bond strength.

• Journal of the Microelectronics and Packaging Society
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• 제29권3호
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• pp.63-71
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• 2022

In this study, the interfacial reaction and drop impact reliability of Sn-Ag-Cu (SAC) solder and electroless nickel autocatalytic gold (ENAG) were studied. In addition, the solder joint properties with the ENAG surface finish was compared with electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG). The IMC thickness of SAC/ENAG and SAC/ENEPIG were 1.15 and 1.12 ㎛, respectively, which were similar each other. The IMC thickness of the SAC/ENIG was 2.99 ㎛, which was about two times higher than that of SAC/ENAG. Moreover, it was found that the IMC thickness of the solder joint was affected by the metal turnover (MTO) condition of the electroless Ni(P) plating solution, and it was found that the IMC thickness increased when the MTO increased from 0 to 3. The shear strength of SAC/ENEPIG was the highest, followed by SAC/ENAG and SAC/ENIG. It was found that when the MTO increased, the shear strength was lowered. In terms of brittle fracture, SAC/ENEPIG was the lowest among the three joints, followed by SAC/ENAG and SAC/ENIG. Likewise, it was found that as MTO increased, brittle fracture increased. In the drop impact test, it was confirmed that the 0 MTO condition had a higher average number of failures than the 3 MTO condition, and the average number of failures was also higher in the order of SAC/ENEIG, SAC/ENAG, and SAC/ENIG. As a result of observing the fracture surface after the drop impact, it was found that the fracture was between the IMC and the Ni(P) layer.

• Journal of Food Hygiene and Safety
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• 제37권5호
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• pp.339-346
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• 2022

This study was performed to investigate the quality characteristics and antioxidant activity of black soybean Sunsik product with functional food ingredients and functional labeling system. We prepared black soybean Sunsik (BS) containing black beans, cereals, and vegetables. Black soybean Sunsik with nondigestible maltodextrin and calcium lactate (BSN) was prepared by adding non-digestible maltodextrin and calcium lactate to the base recipe to apply a functional labeling system. The particle size in BS was 118.00 ㎛, whereas BSN was 127.00 ㎛. The respective L, a, and b color values of BS were 73.25, 2.36, and 14.21. The respective L, a, and b values of BSN were 73.21, 2.36, and 14.31. The respective water retention capacities of BS and BSN were 241.67% and 216.33%. No significant difference was observed between BS and BSN in the three physicochemical properties described above. However, the pH of BSN was 5.45, which was significantly lower than that of BS. The total respective phenolic contents of BS and BSN were 1.75 mg GAE/g and 1.61 mg GAE/g, and total respective flavonoid contents of BS and BSN were 6.36 mg RE/g and 5.95 mg RE/g. The antioxidant capacities of BS and BSN were compared via assays of DPPH and ABTS radical scavenging activities, FRAP, and reducing power. The antioxidant activities of BS and BSN increased in a dose-dependant manner. No significant difference between BS and BSN was observed in any measure of antioxidant capacity. These results suggested that the addition of functional food ingredients (non-digestible maltodextrin and calcium lactate) did not affect the quality characteristics and antioxidant activity of black soybean Sunsik.

• Korean Journal of Poultry Science
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• 제48권4호
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• pp.227-238
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• 2021

This study investigates the effect of perch type and height on the growth performance, footpad dermatitis (FPD), blood parameters, behavioral characteristics, and meat quality of broilers. A total of 912 one-day-old male Ross 308 broilers (48.23±0.264 g) were subjected to a three x two factorial design of three types of perch (wood, steel, plastic) and two levels of perch height (10→30 cm change, 10 cm fixed) over a five-week experiment. Growth performance, perch availability, litter quality, FPD incidence, serum biochemical parameters, and meat quality of the broilers were evaluated. There were no significant differences in the body weight, feed conversion ratio, and biochemical parameters (except for aspartate aminotransferase), pH, color, and water holding capacity. The incidence of FPD was significantly higher in the plastic perch group than in the wood and steel perch groups (P<0.05) at five weeks of age. Perch use was high in the order of wood, steel, and plastic groups in the daytime and nighttime at one, three, and five weeks of age (P<0.05). Perch use was higher in the 10 cm fixed group than the 10→30 cm group (P<0.05). The shear force of the breast significantly increased in the order of wood, steel, and plastic groups (P<0.05). In conclusion, the group with a fixed perch height of 10 cm had high perch usage. Additionally, the use of wooden perches was higher than that of other materials, and it lowered the incidence of FPD in broilers.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• 제28권3호
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• pp.175-182
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• 2022

Heavy metals can be intentionally or unintentionally introduced into plastic food utensils, containers, and packaging (PFUCP) as additives or contaminants, which can be ingested with food by humans. Here, seven-heavy metals (lead, cadmium, nickel, chromium, antimony, copper, and manganese) with toxicity concerns were selected, and risk assessment was done by establishing their migration from 137 PFUCP products made of 16 materials distributed in Korea. Migration of heavy metals was examined by applying 4% acetic acid as a food simulant (70℃, 30 minutes) to the PFUCP products. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for the analysis of migrated heavy metals, and the reliability of quantitative results was confirmed by checking linearity, LOD, LOQ, recovery, precision, and expanded uncertainty. As a result of monitoring, heavy metals were detected at a level of non-detection to 8.76 ± 11.87 ㎍/L and most of the heavy metals investigated were only detected at trace amounts of less than 1 ㎍/L on average. However, antimony migrated from PET products was significantly higher than other groups. Risk assessment revealed that all the heavy metals investigated were safe with a margin of exposure above 311. Collectively, we demonstrated that heavy metals migrated from PFUCP products distributed in Korea appear to be within the safe range.

• Journal of the Korea Organic Resources Recycling Association
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• 제30권2호
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• pp.17-28
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• 2022

The application of supplemental activated biochar pellet fertilizers (ABPFs) was evaluated by investigating key factors such as changes of surface paddy water and soil chemical properties and rice growth responses during the growing season. The treatments consisted of control, activated rice hull biochar pellet (ARHBP-40%), and activated palm biochar pellet (APBP-40%) applications. It was shown that the lowest NH₄⁺-N and PO₄^--P concentrations were observed in surface paddy water to the ARHBP-40%, while the NH₄⁺-N concentration in the control was abruptly decreased until 30 days after transplant in the soil. However, the lowest NH₄⁺-N concentration in the blended biochar application was 9.18 mg L^-1 at 1 day of transplant, but its ABPFs application was observed to be less than 1 mg L^-1 at 56 days after transplant. The lowest PO₄^--P concentration in paddy water treated ARHBP-40% ranged from 0.06 mg L^-1 to 0.08 mg L^-1 until 30 days after transplant among the treatments. For the paddy soil, the NH₄⁺-N concentration in the control was abruptly decreased from 177.7 mg kg^-1 to 49.4 mg kg^-1, while NO₃^--N concentration was highest, 13.2 mg kg^-1 in 14 days after transplant. The P₂O₅ concentrations in the soils increased from rice transplants until the harvesting period regardless of the treatments. The highest K₂O concentration was 252.8 mg kg^-1 in the APBP-40% at 84 days after transplant. For the rice growth responses, plant height in the control was relatively high compared to others, but grain yield was not significantly different between the control and ARHBP-40%. The application of ARHBP-40% can minimize nitrogen and phosphorous application rates into the agro-ecosystem.

• Journal of Bio-Environment Control
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• 제31권3호
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• pp.143-151
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• 2022

This study was carried out to investigate quantitative characteristics of the cooling effect in a single-span arch greenhouse with roll-up side vents depending on operation of circulation and exhaust fans during ventilation, in order to suggest a practical strategy regarding installation or operation of forced ventilation systems. The examination was conducted under 3 different ventilation conditions (side vents only, side vents + circulation fans, and side vents + circulation fans + exhaust fans). In each condition, variations of internal and external air temperatures and exogenous environmental factors were recorded during ventilation, and the cooling effects were investigated by comparing the normalized temperature difference (NTD) of each ventilation condition. In the morning time (11:00-12:00), a temporary peak in the temperature difference was observed at the beginning of ventilation regardless of ventilation methods. The time taken to the maximum NTD was decreased from 340 s to 110s, and the NTD was dropped from 1.158 to 1.037 as the more forced ventilation systems were operated. The more operations caused the passing time over specific NTD values reduced by 60% as the time was reduced from 1,030 s to 550 s at NTD = 0.8, 1,610 s to 915 s at NTD = 0.6, and 2,315 s to 1,360 s at NTD = 0.4. The temporary peak in NTD was not observed in the afternoon time (14:00-15:00) but it was dropped as quickly as the ventilation started. Also the more operations resulted in the passing time over specific NTD values reduced by 70% as the time was reduced from 560 s to 345 s at NTD = 0.8, from 825 s to 540 s at NTD = 0.6, and from 1,145 s to 810 s at NTD = 0.4. Conclusively, the intervention of the forced ventilation system is recommended in the morning time or in high thermal conditions to achieve more effective and economical ventilation.