• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.617-624
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• 2021

Concrete-filled steel tubular columns can improve the strength and deformation capacity of structures, thereby enabling the development of efficient structures. The Korean design standard (KDS41) regarding concrete-filled steel tubular structures, established by the architectural institute of Korea in 2005, was revised in 2009 and 2016. The objective was to understand the compressive strengths and deformation capacity of stub columns for concrete-filled square steel tubes under uniaxial compression and validate the KDS41's standard code for necessary corrections. Experiments were conducted on 26 specimens with parameters, such as the width-thickness ratio of cold-formed square tubes. The following values of the stub columns for concrete-filled square steel tubes were obtained: compressive strengths, relationship between the axial load and axial displacement, and failure modes. An analysis of these results enabled an understanding of the concrete-filled effect and the influence of the wide-thickness ratio. The compressive strengths of filled concrete saw a 9% increase compared to a state of uniaxial stress, which must be noted in a future edition of KDS41. After benchmarking the results regarding square steel tubes generated by cold forming to the guidelines provided by the KDS41, the KDS41's value of 2.26 for the limiting width-to-thickness ratio for the compact section was found to be inflated. With a safety concern, this paper proposes a more conservative value of 1.35.

• Animal Bioscience
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• v.34 no.3_spc
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• pp.417-426
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• 2021

Objective: Effects of inulin supplementation in diet of Haidong chicks under hypoxic conditions on production performance, intestinal morphologic change, microflora contents and the incidence of ascites were studied. Methods: Commercial male chicks (360) were randomly divided into 6 groups and were fed diets supplemented with 0, 0.05, 0.075, 0.1, 0.125, and 0.15 g/kg of inulin, respectively. Results: The body weight gain and feed intake were improved in chicks fed the diets supplemented with 0.1 and 0.125 g/kg of inulin, from d 1 to d 42 (p<0.05); moreover, blood parameters were positively affected when inulin was included in the diets and the thickness of the intestinal wall and muscle tissue in duodenum, jejunum, and ileum tended to increase (p<0.05), and the villi height and crypt depth in duodenum, jejunum, and ileum (p<0.05). Regarding the number of goblet cells in duodenum, jejunum and ileum tended to increase when chicks were fed the diets supplemented with 0.075, 0.1, 0.125, and 0.15 g/kg (p<0.05) of inulin. When chicks were fed diets supplemented with 0.75 or 0.1 g/kg of inulin, a significant reduction of Escherichia coli counts in the cecum was observed; for a contrary, a significant increment of Bifidobacterium and Lactobacillus was observed in cecum and ileum. Finally, supplementing the feed with inulin determined an overall reduction of ascites incidences in comparison to the control group. Conclusion: Thus, the results observed in the present study clearly suggest that the diet supplementation with a quantity of inulin ranging between 0.1 and 0.125 g/kg, can improve growth performances, intestinal morphology, internal microbial balance and ascites incidence, in broiler chicks raised at high altitude area. Even though these findings may be of interest for the poultry industry, they may particularly be relevant in those areas characterized by high altitude such as Northwest China regions.

• Animal Bioscience
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• v.34 no.4
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• pp.662-669
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• 2021

Objective: Effects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated. Methods: The animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction. Results: The LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control. Conclusion: Fatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.66-74
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• 2021

The objective of this study is to evaluate the practical application potential and limitations of the modified fly ash(MFA) by vibration grinding as a partial replacement of ordinary portland cement(OPC). The test parameters investigated were the replacement level of fly ash(FA) and FA for OPC, varying from 10% to 40%, and curing temperatures of 5, 20, and 40℃. The various characteristics(including slump, air content, bleeding, setting time, compressive strength development, and hydration products) of MFA concrete were measured and then compared with those of the concrete with conventional FA. Test resul ts showed that the MFA prefers to FA in reducing the bl eeding of fresh concrete and enhancing the compressive strength gain at an early age. The compressive strength ratios between MFA and FA concrete specimens at an age of 1 day were 135%, 146%, and 111% at the curing temperatures of 5, 20, and 40℃, respectively. The corresponding ratios at an age of 28 days were approximately 110%, regardless of the curing temperatures. The X-ray diffraction analysis also revealed less calcium hydroxide products in MFA pastes than in FA pastes.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.625-634
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• 2022

The objective of this study was to examine the relationship between physical activity (PA) level and functional fitness (FF) parameters in community-dwelling older adults aged 65 or above in Korea. Subjects' (M: 1,645; F: 2,394) PA level were assessed using a questionnaire. The subjects were divided into two groups: one below the recommended level of PA(LPA) and one above the recommended level (PA). PA was further classified by intensity level into medium- and high-intensity PA (MIPA and HIPA respectively) groups. FF was assessed based on six test items representing the following fitness areas: lower and upper body strength, agility and dynamic balance, flexibility, aerobic capacity, coordination, and body composition. Of the subjects, 36% met the recommended level of PA. Both MIPA and HIPA were superior to LPA in all FF items(p<.05). The HIPA group was significantly better in terms of agility and dynamic balance, coordination, and lower body strength (only in women) than was the MIPA group(p<.05). In conclusion, PA above the recommended level is needed to maintain functional fitness. In addition, HIPA seems to promote fall-related functional fitness and should be encouraged when safe and feasible.

• Animal Bioscience
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• v.35 no.2
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• pp.204-216
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• 2022

Objective: The aim of this study was to investigate the effects of dietary supplementation with a multi-strain probiotic (MSP) product containing of Bifidobacterium animalis, Lactobacillus casei, Streptococcus faecalis, and Bacillus cerevisiae on growth, health, and fecal bacterial composition of dairy calves during the first month of life. Methods: Forty Holstein calves (24 female and 16 male) at 2 d of age were grouped by sex and date of birth then randomly assigned to 1 of 4 treatments: milk replacer supplementation with 0 g (0MSP), 2 g (2MSP), 4 g (4MSP), and 6 g (6MSP) MSP per calf per day. Results: Supplementation of MSP did not result in any significant differences in parameters of body measurements of calves during the 30 d period. As the dosage of MSP increased, the average daily gain (p = 0.025) and total dry matter intake (p = 0.020) of calves showed a linear increase. The fecal consistency index of the 2MSP, 4MSP, and 6MSP group calves were lower than that of the 0MSP group calves (p = 0.003). As the dosage of MSP increased, the concentrations of lactate dehydrogenase (p = 0.068) and aspartate aminotransferase (p = 0.081) in serum tended to decrease, whereas the concentration of total cholesterol increased quadratically (p = 0.021). The relative abundance of Dorea in feces was lower (p = 0.011) in the 2MSP, 4MSP, and 6MSP group calves than that in the 0MSP group calves. The relative abundance of Dorea (p = 0.001), Faecalibacterium (p = 0.050), and Mitsuokella (p = 0.030) decreased linearly, whereas the relative abundance of Prevotella tended to increase linearly as the dosage of MSP increased (p = 0.058). Conclusion: The MSP product can be used to reduce the diarrhea, improve the performance, and alter the composition of the fecal bacteria in neonatal dairy calves under the commercial conditions.

• Animal Bioscience
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• v.35 no.1
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• pp.54-63
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• 2022

Objective: This study aimed to evaluate the replacement of degummed soybean oil (DSO) by acid soybean oil (ASO) in diets with or without the inclusion of emulsifier on broiler performance, relative organ weight, lipase activity, intestinal morphometry, and nutrient digestibility. Methods: A total of 704 1-day-old male broiler chicks were allotted to a 2×2 completely randomized factorial design (with or without emulsifier × two lipid sources [ASO and DSO]), with eight replicates and 22 birds each. The metabolizable energy level in diets with emulsifier was reduced by 40 kcal/kg from 1 to 21 d and 50 kcal/kg from 22 to 49 d. Results: Broilers fed diets containing ASO without emulsifier had higher (p = 0.005) weight gain than DSO-fed animals and with the inclusion of emulsifier had worse (p = 0.018) feed conversion ratio (FCR). Birds fed diets with emulsifier worsened FCR regardless of lipid source from 1 to 21 days (p = 0.006) and from 1 to 49 days (p = 0.0002). There was an increase (p = 0.026) in the relative pancreas weight, at 14 days, in birds fed diets containing ASO. Lipase activity and morphometry of the duodenum and jejunum, at 14 and 21 days, were not affected (p>0.05). The dietary inclusion of emulsifier improved the digestible energy (p = 0.053) in the presence of ASO. For the digestibility coefficients (gross energy, crude protein, and mineral matter), no interference was observed (p>0.05). Conclusion: The inclusion of emulsifier to energy-restricted diet with ASO maintained broiler performance in the first week, but worsened FCR in subsequent phases. The ASO can be considered as an alternative lipid source to DSO and does not interfere with the morphophysiological characteristics and performance of broilers. The combination of ASO and emulsifier increased the digestible energy content by 6.2%.

• Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.287-297
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• 2022

The objective of this study was to evaluate the probability of norovirus foodborne illness by raw oyster consumption. One hundred fifty-six oyster samples were collected to examine the norovirus prevalence. The oyster samples were inoculated with murine norovirus and stored at 4℃-25℃. A plaque assay determined norovirus titers. The norovirus titers were fitted with the Baranyi model to calculate shoulder period (h) and death rate (Log PFU/g/h). These kinetic parameters were fitted to a polynomial model as a function of temperature. Distribution temperature and time were surveyed, and consumption data were surveyed. A dose-response model was also searched through literature. The simulation model was prepared with these data in @RISK to estimate the probability of norovirus foodborne. One sample of 156 samples was norovirus positive. Thus, the initial contamination level was estimated by the Beta distribution (2, 156), and the level was -5.3 Log PFU/g. The developed predictive models showed that the norovirus titers decreased in oysters under the storage conditions simulated with the Uniform distribution (0.325, 1.643) for time and the Pert distribution (10, 18, 25) for temperature. Consumption ratio of raw oyster was 0.98%, and average consumption amount was 1.82 g, calculated by the Pert distribution [Pert {1.8200, 1.8200, 335.30, Truncate (0, 236.8)}]. ₁F₁ hypergeometric dose-response model [1 - (1 + 2.55 × 10^-3 × dose)^-0.086] was appropriate to evaluate dose-response. The simulation showed that the probability of norovirus foodborne illness by raw oyster consumption was 5.90 × 10^-10 per person per day. The annual socioeconomic cost of consuming raw oysters contaminated with norovirus was not very high.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.226-234
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• 2021

The objective of this study is to establish the fundamental design data for axial load-displacement relationship under axial monotonic or cyclic responses of seismic damping·isolation (SDI) units developed for ceiling structures. The main parameters include the installation of a spring, the number of rubber layer, prestress stress of bolts for connector between the spring and rubbers, and loading type. Test results showed that SDI units with a spring in the core and higher prestress stress of bolts tended to be higher stiffness at the ascending branch and more ductile behavior at the descending branch. This trends more notable for the specimens under monotonic load rather than cyclic loads. Consequently, the energy dissipation of SDI unit can be optimally designed with the following conditions: installation of a spring within 3-layer rubbers and prestress applied to the bolts at 10% of their yielding strength . When compared with the experimental tension capacity of the developed SDI units, the predictions by JIS B 2704-1 and KDS 31 00 are conservative under monotonic loading but higher by approximately 10% under cyclic loading.

• Animal Bioscience
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• v.35 no.2
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• pp.260-271
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• 2022

Objective: We aimed to investigate the effect of the differing amino acid (AA) release dynamics of two protein sources on the growth performance, nitrogen deposition, plasma biochemical parameters, and muscle synthesis and degradation of piglets when included in their diets at normal and low concentrations. Methods: Forty-eight piglets (Duroc×Landrace×Large White) with initial body weight of 7.45±0.58 kg were assigned to six groups and fed one of 6 diets. The 6 dietary treatments were arranged by 3×2 factorial with 3 protein sources and 2 dietary protein levels. They are NCAS (a normal protein content with casein), NBlend (a normal protein content with blend of casein and corn gluten meal), NCGM (a normal protein content with corn gluten meal), LCAS (a low protein content with casein), LBlend (a low protein content with blend of casein and corn gluten meal), LCGM (a low protein content with corn gluten meal). The release dynamics of AA in these diets were determined by in vitro digestion. The digestibility, utilization and biological value of nitrogen in piglets were determined by micro Kjeldahl method. Plasma insulin was measured by enzyme-linked immunosorbent assay kits. The protein expression of mediators of muscle synthesis and degradation was determined by western blotting. Results: Although the consumption of a low-protein diet supplemented with crystalline AA was associated with greater nitrogen digestion and utilization (p<0.05), the final body weight, growth performance, nitrogen deposition, and phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein 1 in the muscle of pigs in the low-protein diet-fed groups were lower than those of the normal-protein diet-fed groups (p<0.05) because of the absence of non-essential AA. Because of the more balanced release of AA, the casein (CAS) and Blend-fed groups showed superior growth performance, final body weight and nitrogen deposition, and lower expression of muscle ring finger 1 and muscle atrophy F-box than the CGM-fed groups (p<0.05). Conclusion: We conclude that the balanced release of AA from CAS containing diets and mixed diets could reduce muscle degradation, favor nitrogen retention, % intake and improve growth performance in pigs consuming either a normal- or low-protein diet.