• Advances in nano research
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• v.12 no.6
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• pp.605-616
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• 2022

We prepared two samples of ultrafine ferrihydrite (FH) nanoparticle ensembles of quite a different origin. First is the biosynthesized sample (as a product of the vital activity of bacteria Klebsiella oxytoca (hereinafter marked as FH-bact) with a natural organic coating and negligible magnetic interparticle interactions. And the second one is the chemically synthesized ferrihydrite (hereinafter FH-chem) without any coating and high level of the interparticle interactions. The interparticle magnetic interactions have been tuned by modifying the nanoparticle surface in both samples. The coating of the FH-bact sample has been partially removed by annealing at 150℃ for 24 h (hereinafter FH-annealed). The FH-chem sample, vice versa, has been coated (1.0 g) with biocompatible polysaccharide (arabinogalactan) in an ultrasonic bath for 10 min (hereinafter FH-coated). The changes in the surface properties of nanoparticles have been controlled by XPS. According to the electron microscopy data, the modification of the nanoparticle surface does not drastically change the particle shape and size. A change in the average nanoparticle size in sample FH-annealed to 3.3 nm relative to the value in the other samples (2.6 nm) has only been observed. The estimated particle coating thickness is about 0.2-0.3 nm for samples FH-bact and FH-coated and 0.1 nm for sample FH-annealed. Mössbauer and magnetization measurements are definitely shown that the drastic change in the blocking temperature is caused by the interparticle interactions. The experimental temperature dependences of the hyperfine field hf>(T) for samples FH-bact and FH-coated have not revealed the effect of interparticle interactions. Otherwise, the interparticle interaction energy E_int estimated from the hf>(T) for samples FH-chem and FH-annealed has been found to be 121k_B and 259k_B, respectively.

• Animal Bioscience
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• v.35 no.6
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• pp.902-915
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• 2022

Objective: Diet acidification supplementation is known to influence intestinal morphology, gut microbiota, and on phosphorus (P) utilization of broilers. Alterations in intestinal barrier and microbiota have been associated with systemic inflammation and thus regulating bone turnover. Hence the effect of acidifier addition to drinking water on tibia mass and the linkages between intestinal integrity and bone were studied. Methods: One-d-old male broilers were randomly assigned to normal water (control) or continuous supply of acidified water (2% the blend of 2-hydroxy-4-methylthiobutyric acid, lactic, and phosphoric acid) group with 5 replicates of 10 chicks per replicate for 42 d. Results: Acidification of drinking water improved the ash percentage and calcium content of tibia at 42 d. Broilers receiving acidified water had increased serum P concentration compared to control birds. The acidified group showed improved intestinal barrier, evidenced by increased wall thickness, villus height, the villus height to crypt depth ratio, and upregulated mucin-2 expression in ileum. Broilers receiving drinking water containing mixed organic acids had a higher proportion of Firmicutes and the ratio of Firmicutes and Bacteroidetes, as well as a lower population of Proteobacteria. Meanwhile, the addition of acidifier to drinking water resulted in declined ileal and serum proinflammatory factors level and increased immunoglobulin concentrations in serum. Concerning bone remodeling, acidifier addition was linked to a decrease in serum C-terminal cross-linked telopeptide of type I collagen and tartrate-resistant acid phosphatase reflecting bone resorption, whereas it did not apparently change serum alkaline phosphatase activity that is a bone formation marker. Conclusion: Acidified drinking water increased tibia mineral deposition of broilers, which was probably linked with higher P utilization and decreased bone resorption through improved intestinal integrity and gut microbiota and through decreased systemic inflammation.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.574-587
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• 2022

This study was performed to development the alternative farrowing pen (AFP) and to investigate performance and behavior of lactating sows and their litter. A total of 64 multiparous sows were randomly divided into two groups and were allocated to farrowing crates (FCs) and AFPs. The AFPs contained a crate and support bars that could be folded to provide the sows with extra space on day 5 postpartum. Behavior was recorded by charge-coupled device cameras and digital video recorders, and the data were scanned every 2 min to obtain an instantaneous behavioral sample. Farrowing systems did not affect feed intake, back-fat thickness, litter size and piglet weight at birth and weaning (p > 0.05). In addition, there were no differences in the number of crushed piglets between the two farrowing systems (p > 0.05). However, the weaning-to-estrus interval was shorter in the sows of the AFPs than in thous of the FCs (p < 0.05). The sows spent most of their time lying down during the lactating period, at about 80% lateral recumbency and 10%-15% ventral recumbency. The only significant differences were in the feeding and drinking behavior between sows in the two farrowing systems (p < 0.05). The FC sows displayed more feeding and drinking behavior than the AFP sows, especially in the late lactating period (p < 0.05). Piglets in the FCs tended to spend more time walking than piglets in the AFPs (p < 0.05), whereas there were no differences in suckling and lying behavior between piglets in the two farrowing systems (p > 0.05). It is concluded that the AFPs with temporary crating until day 4 postpartum did not negatively affect performance and crushed piglet compared with the FCs. It also may improve animal welfare by allowing sows to move and turn around during the lactating period. Further research is needed to find suitable housing designs to enhance productivity and animal welfare.

• Korean Journal of Acupuncture
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• v.39 no.4
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• pp.152-171
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• 2022

Objectives : This study was designed to investigate the effects of Sunbanghwalmyung-eum gamibang on Monosodium iodoacetate-induced osteoarthritis rats. Methods : Forty Sprague-Dawley (SD) rats were divided into 5 groups of 8 rats each. Osteoarthritis (OA) was induced by injecting MIA (2 mg/50 µl) into the joint cavity of the left knee of SD rats belonging to the experimental group, and normal saline was injected into the joint cavity of the left knee instead of MIA in the normal group. To the normal group and the controlled group (OA group), 2 ml of distilled water was orally administered. To the positive control group (Indomethacin group), indomethacin 2 ml at a concentration of 2 mg/kg, to the low concentration group of SHG (Low group), 2 ml of SHG at a concentration of 2 mg/kg, and to the high concentration group of SHG (High group), 2 ml of SHG at a concentration of 4 mg/kg ml was orally administered. The drug was administered for a total of 4 weeks, and histological changes were analyzed by Hematoxylin-Eosin staining and Safranin-O staining. In addition, inflammatory cytokines such as TNF-α, IL-1β, and IL-6, and MMP-13, TIMP-1, and GAGs were immunohistochemically analyzed. Finally, hematological examination, blood biochemical examination, and liver and kidney biopsy were performed. Results : SHG groups (Low and High) inhibited the matrix destruction and damage of the knee joint cartilage in SD rat model, and significantly prevented the reduction in cartilage thickness. In SHG groups, the expressions of TNF-α, IL-1β, IL-6 and MMP-13 were significantly decreased, and the expressions of TIMP-1, GAGs were significantly increased compared with OA group. The safety indicators had no significant differences among five groups. Conclusions : These results show that SHG has cartilage protection capacity, anti-inflammatory effect.

• Journal of the Korean Society of Safety
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• v.38 no.4
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• pp.39-46
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• 2023

Pine trees, which account for 23% of the forested area of the Republic of Korea, are highly vulnerable to fire in comparison to broad-leaved trees due to the presence of consistent water tube sections throughout the year and resin that is composed of approximately 20% oil. In addition, the pattern of forest fires is determined by weather, topographic conditions, and fluctuation in moisture content. Therefore, when fire breaks out in pine tree forests during the dry season (January to March), it is difficult to extinguish, and it quickly spreads. In this study, the combustion characteristics of pine needles, pine cones, and pine branches in the water tube sections of living pine trees were compared and analyzed in accordance with the moisture content as per the ISO 5660-1. The monthly moisture content was analyzed from January to March, and it was found to be the lowest in March, with 53.6% for pine needles, 51.9% for pine branches, and 10.9% for pine cones. In particular, pine cones were more vulnerable to fire as compared to pine needles and pine branches because their moisture content was more than five times lower than that of pine needles and branches. The ignition time, which affects the speed of flame propagation, was the most rapid in March, and the fastest ignition time was for pine cones, at 19 seconds, followed by 34 seconds for pine needles, and 256 seconds for pine branches. The pine branches were the last to be ignited due to the effect of density, according to the thickness and specific gravity of the specimen. The peak heat release rate, which is a measurable index of fire intensity, was analyzed for pine cones and found to be 184.28 kW/m² , while the mean effective heat of combustion was 19.79 MJ/kg, and the total heat release rate was 39.7 MJ/m² , and these values were higher than those of pine branches and pine needles. Thus, we determined that the flame propagation speed and fire intensity according to the moisture content can be used to evaluate the risk of fire to the water tube section of pine trees. It is suggested that because of the combustion characteristics of the pine cone in March, that is when the forest is most vulnerable to fires.

• The Journal of Advanced Prosthodontics
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• v.15 no.5
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• pp.238-247
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• 2023

PURPOSE. The purpose of this study was to assess the effect of resin cement shade on the color of different novel ultratranslucent monolithic zirconia and lithium disilicate veneer materials. MATERIALS AND METHODS. For a total of 40 specimens, flat cylindrical discs with a 9-mm diameter and 0.5-mm thickness were created using CAD/CAM technology. The specimens were divided into five groups according to their material (n = 8) (e.max, Prettau, Aidite, Shofu and Dima) using A1 shade. Resin discs with the same diameter and shade as the specimens served as tooth-colored substructures. Three shades (neutral, light and warm) of resin cement try-in pastes (Variolink Esthetic LC) were used as the luting cement material. The color of each material group was measured before and after cementation using the three cement shades, and the CIE L^*a^*b^* coordinates were obtained with a spectrophotometer. Values for the translucency parameter (TP) and color change delta E (E) before (baseline) and after cementation of each specimen were determined. To compare differences among the material groups within each shade of cement and among various shades of cement within each material, the data were analyzed using one-way ANOVA and post hoc testing. RESULTS. Color coordinates L^*, a^* and b^* significantly changed after the application of try-in pastes relative to baseline values, with a noticeable decrease in lightness (L^*) (P < .05). A significant color change (ΔE) was observed in all tested materials after cementation, with ΔE values exceeding 3.3 (P < .05). Although TP changed after cementation for most materials tested, these changes were not statistically significant (P > .05). Shofu and Dima ceramics showed the lowest TP values, while Aidite and Prettau showed the highest TP values. For e.max, translucency decreased after cementation with neutral and warm shades, and it significantly increased after cementation with a light shade. CONCLUSION. The shade of cement significantly altered the final color of the ceramic veneer material to a level above the threshold at which the clinical perception of color change occurred (> 3.3). The TP was not influenced by the cement shade. The translucency levels of the novel ultratranslucent multilayer monolithic zirconia ceramics Aidite and Prettau were higher than that of the lithium disilicate e.max material.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1323-1340
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• 2023

There are several factors that affect the welfare and meat quality of pigs during pre-slaughter transport. Among various factors, the effects of weather conditions and loading density were studied. A total of 3,726 finishing pigs were allotted to one of nine groups arranged in a 3 × 3 factorial design according to the weather conditions (low temperature [LT], under 10℃; normal temperature [NT], 10℃-24℃; high temperature [HT], upper 24℃), and loading density (low density [LD], upper 0.43 m²/100 kg; normal density [ND], 0.37-0.43 m²/100 kg; high density [HD], under 0.37 m²/100 kg). Each treatment group follow as: LTLD, LTND, LTHD, NTLD, NTND, NTHD, HTLD, HTND, HTHD. In terms of carcass composition, pigs had the highest carcass weight and backfat thickness at LT. Comparing the HD transport to the ND transport, the meat quality indicated a lower pH and more drip loss. The incidence rate of pale, soft, exudative (PSE) pork was high in the order of the HD, LD, and the ND transport (20%, 9%, and 2%, respectively). The HT transport showed the lowest pH and greatest L^* value under the given weather conditions. Pigs transported under the HTHD and LTLD conditions had the greatest rates of PSE pork (40% and 20%, respectively). Pigs exposed to HD transport had the shortest laying time and the highest overplap behavior. The LDLT transport pigs had a shorter laying time than the LDNT and LDHT transport pigs. In conclusion, too high or too low density transport is generally not excellent for meat quality or animal welfare, however it is preferable to transport at a slightly low density at high temperature and at a slightly high density at low temperature.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1214-1225
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• 2023

We investigated the effect of energy levels on growth performance, carcass characteristics, and fatty acid composition of Holstein steers at different slaughter ages. Forty Holstein steers with an average body weight (BW) of 234.21 ± 7.42 kg and 7.78 ± 0.22 months were randomly allocated to two experimental groups; a 22-month-old experimental group and a 24-month-old experimental group. Total digestible nutrients (TDN) for each group were set to 70% (T1) and 72% (T2) during fattening phase and 74% (T3) and 76% (T4) for the finishing phase, respectively. No difference was observed in the final BW between the experimental groups during the fattening phase. However, in the finishing phase, the final BW of T4 (820.31 kg) group was significantly higher than that of T1 (745.57 kg; p < 0.05). The average daily gain (ADG) of T2 group in the finishing phase and overall period were 1.27 kg and 1.26 kg, respectively, which were significantly higher than those of T1 (1.11 kg and 1.12 kg; p < 0.05). The feed conversion ratio (FCR) and TDN conversion ratio of T2 group in the finishing phase also decreased by 10.23% and 7.73%, respectively, compared to those of T1. The cold carcass weight of T4 group was significantly higher (p < 0.05) than that of T1, whereas back fat thickness, longissimus area, and marbling score were not significantly different among groups. No differences were observed in physicochemical characteristics of the carcass including moisture, crude protein, and crude fat content among groups. However, the composition of fatty acids differed significantly between the groups. The content of C18:0 was significantly lower (p < 0.05) in T4 than in T1 group, and the content of C18:2 was higher in T4 than in T1 and T3 (p < 0.05). Therefore, feeding Holstein steers at a high-energy feeding level during the fattening and finishing phases improves ADG and reduces the slaughter age from 24 months to 22 months.

• Composites Research
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• v.36 no.5
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• pp.289-296
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• 2023

In this study, we investigated the electromagnetic properties and microwave absorption characteristics of M-type hexagonal ferrites, which are known as millimeter-wave absorbing materials, according to their calcination temperature. The M-type ferrites synthesized using a molten salt-based sol-gel method exhibited a single-phase M-type crystal structure at calcination temperatures above 850℃. The synthesized particle size increased as well with the calcination temperature. Saturation magnetization increased gradually with increasing calcination temperature, but coercivity reached a maximum at 1050℃ and then rapidly decreased. After preparing a thermoplastic polyurethane (TPU) composite containing 70 wt% of M-type ferrites, we measured the complex permittivity and permeability in the Q-band (33-50 GHz) and V-band (50-75 GHz) frequency ranges, where ferromagnetic resonance occurred. Strong magnetic loss from ferromagnetic resonance occurred in the 50 GHz band for all composite samples. Based on the measured results, we calculated the reflection loss of the TPU/M-type ferrite composite. By calculating the reflection loss of the M-type ferrite composite, the M-type ferrite calcined at 1250℃ showed excellent electromagnetic wave absorption performance of more than -20 dB at 52 GHz with a thickness of about 0.5 mm.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1011-1017
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• 2023

In this study, the harmless crack size (a_hml) by double shot peening (DSP) using shot balls with different diameters was evaluated on carburized, quenched-tempered SCM822H steel. The minimum crack size (a_NDI) detectable by non-destructive inspection was also evaluated. The relationship between the crack size (a_25,50) that reduces the fatigue limit by 25% and 50% and a_hml was evaluated. The residual stress of DSP was greater in SP_(0.6+0.08) than SP_(0.8+0.08) and appeared deeper in the depth direction. In addition, the hardness below the surface appeared larger. The fatigue limit of DSP increased 2.07 times and 1.95 times compared to non-SP. All a_hml of the DSP specimen was determined at the depth (a). The compressive residual stress distribution affects a_hml, and the a_hml of SP_(0.6+0.08), which has a large compressive residual stress and a high fatigue limit, appeared large. a_hml of SP_(0.6+0.08) introduced deeper than the residual stress of SP_(0.8+0.08) is larger in the range of As=1.0-0.3. Since the residual stress in the thickness direction has a greater effect on a_hml than the residual stress at the surface, it is necessary to introduce it more deeply. The relation of a_hml, a_25,50, and a_NDI were evaluated in the point for safety and reliability.