• 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.

• Polymer(Korea)
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• v.39 no.3
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• pp.441-452
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• 2015

Twin-screw kneader is an efficient polymer processing equipment. In this paper, the mixing performance of one novel intermeshing counter-rotating twin-screw kneader with different tip angles of the male rotor is simulated using the mesh superimposition technique (MST). Statistical analysis is carried out for the flow field using particle tracking technique, and distributive mixing performance is evaluated using the residence time distribution and segregation scale, while the dispersive mixing performance is estimated using the parameters such as shear rate, stretching rate and mixing index. The results show that the best distributive mixing performance is achieved when the tip angle is 0o, while the optimal dispersive mixing performance is obtained when the tip angle is 20o. The results in this paper provide a data basis for the selection of parameters and optimization of the performance for the screw rotors.

• The KSFM Journal of Fluid Machinery
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• v.19 no.1
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• pp.5-10
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• 2016

As a key component of a Francis turbine facility, the runner performance plays a vital role in the performance of the turbine. It is effective and successful to design a Francis turbine runner blade with good performance by one dimensional hydraulic design method. On the basis of one dimensional hydraulic analysis, there are a lot of parameters of the internal flow passage shapes determined by experience. Among those parameters, the effect of port area of blade on the performance of a Francis turbine is investigated in this study. A given Francis turbine model was selected for investigating the port area of blade on the performance. The result shows that the effect of port area of runner blade on the outflow angle from runner passage on the performance is quite significant. A correct exit flow angle reduces the energy loss at draft tube, which has the best efficiency of the turbine model.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.872-876
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• 2006

The objective of this study was to evaluate Biocom (a protein source containing a high level of glutamine and alanyl-glutamine) as a replacement for glutamine (Gln) in nursery pig diets. Forty-two pigs (fourteen pigs per treatment) weaned at 28 d of age were used in a 28-d performance trial using three dietary treatments: control (no Gln), control supplemented with Gln or Biocom. The control diet was composed of corn, soybean meal, whey and fish meal. Individual body weight, pen feed disappearance and diarrhea were monitored. On d 0, 2, 7 and 14 postweaning, respectively, five pigs per treatment were selected and bled from the anterior vena cava to obtain five replicate samples of blood on each dietary treatment for determination of blood biochemical index. Dietary supplementation of Gln and Biocom did not influence performance, plasma Gln and total serum protein concentration (p>0.05). However, the addition of Gln and Biocom could prevent serum urea nitrogen and serum cortisol from increasing on d 2 postweaning (p<0.05). There were no significant differences (p>0.05) in any of the examined parameters between Gln- and Biocom-supplemented diets. In conclusion, dietary Gln did not influence the performance of early-weaned piglets owing to the complex diet containing whey, but could prevent the increase of serum urea and cortisol. Biocom could be used as a replacement for free pure Gln without any negative effect on early-weaned piglets.

• Steel and Composite Structures
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• v.32 no.2
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• pp.189-198
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• 2019

This paper aims to study the mechanical performance of three-tower four-span suspension bridges with steel truss girders, including the static and dynamic characteristics of the bridge system, and more importantly, the influence of structural parameters including the side-main span ratio, sag-to-span ratio and the girder stiffness on key mechanical indices. For this purpose, the Oujiang River North Estuary Bridge which is a three-tower four-span suspension bridge with two main spans of 800m under construction in China is taken as an example in this study. This will be the first three-tower suspension bridge with steel truss girders in the world. The mechanical performance study and parametric analysis are conducted based on a validated three-dimensional spatial truss finite element model established for the Oujiang River North Estuary Bridge using MIDAS Civil. It is found that a relatively small side-main span ratio seems to be quite appropriate from the perspective of mechanical performance. And decreasing the sag-to-span ratio is an effective way to reduce the horizontal force subjected to the midtower and improve the antiskid safety of the main cable, while the vertical stiffness of the bridge will be reduced. However, the girder stiffness is shown to be of minimal significance on the mechanical performance. The findings from this paper can be used for design of three-tower suspension bridges with steel truss girders.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.355-360
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• 1995

A series of 15 reinforced concrete beams was tested to evaluate the flexural performance of the repaired RC beams. the key parameters for this study were the repair materials, polymer/cementitious materials, in addition to the strengthening material, steel plates and carbon fiber sheets. The repaired specimens failed by a typical flexural mode. showing minor interface failure. The results show that epoxy, polyester resins and latex modified cementitous mortars are effective for repairing the concrete beams. However, the flexural preformance of the strengthened beams are varied depending on the repaired materal.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.7-12
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• 1989

This paper describes the design and development of a PWM electronic controller for a high performance Pneumatic Actuation System. The task includes the design of a closed center valve circuit for minimum gas consumption, the selection of optimum values for key parameters in the PWM circuit, and the design of lag-lead compensation circuit. These were carried out through specific experiments using a prototype pneumatic actuation system. The final performance obtained with the actuation system confirmed the successful design of the developed PWM electronic controller.

• Parasites, Hosts and Diseases
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• v.54 no.3
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• pp.301-305
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• 2016

In order to determine the effect of various hosts on feeding performance of Rhipicephalus (Boophilus) microplus, we used 3 mammalian species as hosts, cattle (Qinchuan), sheep (Tan), and rabbits (Japanese white rabbit) for infesting ticks. Five hundreds of R. microplus larvae were exposed to each animal (3 animals/host species). Tick recoveries were 11.0%, 0.47%, and 5.5% from cattle, sheep, and rabbits, respectively. The averages of tick feeding periods were not significantly different on cattle, sheep, and rabbits, 28.8, 25.3, and 26.7 days, respectively. The average weights of individual engorged female from cattle, sheep, and rabbits were 312.5, 219.1, and 130.2 mg, respectively and those of egg mass weights each to 85.0, 96.6, and 17.8 mg. The highest egg hatching rate was in the ticks from cattle (96.0%), followed by those from rabbits (83.0%) and sheep (19.2%). These data suggest that rabbits could be as an alternative host to cultivate R. microplus for evaluating vaccines and chemical and biological medicines against the tick in the laboratory, although the biological parameters of ticks were less than those from cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.750-756
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• 2010

Two trials were conducted to study the effects of two Chinese herbal polysaccharides, Astragalus polysaccharides (APS) and Achyranthes bidentata polysaccharides (ABPS), and one Chinese herbal saponin, Acantbepanax senticosus saponin (ASS), on the immunity and growth performance of weaned pigs. Experiment 1 was a 14-day growth assay, in which 32 weaned pigs were randomly allocated to one of four dietary treatments: i) 0.05% talcum powder control; ii) 0.05% APS; iii) 0.05% mixture of APS and ASS in a 1:1 ratio by weight; and iv) 0.05% mixture of APS, ASS, and ABPS in a ratio of 1:1:1 by weight. Blood samples were collected on day 14 to determine plasma parameters. Feed intake, body weight gain, and feed efficiency were also determined. Experiment 2 was a 21-day immunity assay, in which 16 weaned pigs were randomly allotted to one of two dietary treatments: i) 0.05% talcum powder control; and ii) 0.05% mixture of APS and ASS in a 1:1 ratio by weight. On day 21, pigs were challenged with lipopolysaccharide (LPS) and 3 h later blood samples were collected and analyzed for lymphocyte proliferation as well as interleukin 6 (IL-6), insulin-like growth factor 1 (IGF-1), growth hormone (GH), and cortisol levels. In Experiment 1, feeding Chinese herbal polysaccharides and saponin increased growth performance of the pigs. The effects of the mixture of APS and ASS were especially notable, as there was a significant improvement in growth performance compared with the control (p<0.05). The plasma concentration of immunoglobulin G (IgG), nitric oxide (NO), and nitric oxide synthase (NOS) were increased in all treatments groups, with the mixture of APS and ASS increasing the level of IgG and NOS significantly (p<0.05), compared with the control. There was no difference in the NO level between the control and treatment groups (p>0.05). In Experiment 2, Chinese herbal polysaccharides and saponin showed immunostimulating effects. The level of cortisol, GH, and IGF-I were significantly increased (p>0.05), and the level of IL-6 showed a significant decrease (p<0.05) in the APS and ASS treatment after the LPS challenge. The mixture of APS and ASS could stimulate the blood lymphocyte proliferation significantly whether the LPS was injected or not (p<0.05). These results show that Chinese herbal extracts can improve growth performance and stimulate immunity of weaned pigs. A mixture of APS and ASS, compared with APS alone, could be a new kind of immunostimulant for weaned pigs, which could result in greater positive effects on their growth performance and immunity.

• Tunnel and Underground Space
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• v.21 no.6
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• pp.427-438
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• 2011

Segment lining is a key permanent lining structure to maintain the shield tunnel stability in shield tunnel operation. Moreover, segment lining generally accounts for the largest proportion in the shield tunnel construction costs. As a result, technical improvements to increase its economic feasibility have been actively carried out. This study aims to propose the development directions of high-performance segments from their recent cutting technologies. In addition, based on over 2,100 world-widely collected segment design data, a series of statistical analyses of segment key design parameters such as thickness, width and the number of divisions as well as segment materials were carried out to approximately estimate them in a design stage.