• Current Applied Physics
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• v.18 no.11
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• pp.1388-1392
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• 2018

Metal thin films are used widely to solve the vibration problem. However, damping mechanism is still not clear, which limits the further improvement of the damping properties for film and the development of multi-functional damping coating. In this paper, Damping microscopic mechanism of porous metal films was investigated at both macroscopically and microscopically mixed levels. Molecular dynamics simulation method was used to model and simulate the loading-unloading numerical experiment on the micro-pore and vacancy model to get the stress-strain curve and the microstructure diagram of different defects. And damping factor was calculated by the stress-strain curve. The results show that dislocations and new vacancies appear in the micro-pores when metal film is stretched. The energetic consumption from the motion of dislocation is the main reason for the damping properties of materials. Micro-mechanism of damping properties is discussed with the results of in-situ experiment.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.31-34
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• 2006

Laboratory experiment of polarimetric GPR measurement was conducted for the purpose of estimating subsurface inhomogeneity. Tow realization of inhomogeneous subsurface media were made by burying stone objects of different dimensions in homogeneous dry sand. Polarization ratio of cross polarization to co polarization data were examined to find their obviously distinguishable behavior.

• Journal of Pharmaceutical Investigation
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• v.26 no.4
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• pp.281-289
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• 1996

In our previous work, we have studied the effect of lactose and sodium alginate (SA) on the rate of release of 5-fluorouracil (5-FU) from ethylene-vinyl acetate (EVA) matrix. These hydrophilic additives promoted the rate of 5-FU release and the increase in rate was larger when SA was used. Both additives showed better ability to increase the rate than 5-FU itself. In this paper, we extended our study to another hydrophilic additive, Carbopol 940 (CP). Compared to SA or lactose, CP increased the rate of 5-FU release markedly. Release rate increased as the loading amount and the pH of the release medium increased. After release experiment, matrix volume increased up to 15 times of that before release experiment, depending on the amount of CP dispersed in the matrix and the pH of the release medium. On the other hand, the volume of the matrix containing lactose or SA decreased. The weight changes of the dry matrix before and after release experiment imply that CP is not released out of the matrix, to the contrary of lactose and SA. Scanning electron microscope study clearly showed that large cavities and pores are generated on the surface and the inside of the matrix. These results indicate that the mechanism by which CP increases the release rate is quite different from that of monomeric additives such as lactose or SA.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2728-2735
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• 2022

The research on the flow and heat transfer characteristics of lead bismuth(LBE) is significant for the thermal-hydraulic calculation, safety analysis and practical application of lead-based fast reactors(LFR). In this paper, a new CFD model is proposed to solve the thermal-hydraulic analysis of LBE. The model includes two parts: turbulent model and turbulent Prandtl, which are the important factors for LBE. In order to find the best model, the experiment data and design of 19-pin hexagonal rod bundle with spacer grid, undertaken at the Karlsruhe Liquid Metal Laboratory (KALLA) are used for CFD calculation. Furthermore, the turbulent model includes SST k - 𝜔 and k - 𝜀; the turbulent Prandtl includes Cheng-Tak and constant (Pr_t =1.5,2.0,2.5,3.0). Among them, the combination between SST k - 𝜔 and Cheng-Tak is more suitable for the experiment. But in the low Pe region, the deviation between the experiment data and CFD result is too much. The reason may be the inlet-effect and when Pe is in a low level, the number of molecular thermal diffusion occupies an absolute advantage, and the buoyancy will enhance. In order to test and verify versatility of the model, the NCCL performed by the Nuclear Thermal-hydraulic Laboratory (Nuthel) of Xi'an Jiao tong University is used for CFD to calculate. This paper provides two verification examples for the new universal model.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.1012-1020
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• 2013

The objective of this study was to investigate the effect of dietary supplementation with thiazolidinedione (TZD) on growth performance and meat quality of finishing pigs. In Experiment 1, 80 castrated finishing pigs (Large White${\times}$Landrace, BW = 54.34 kg) were randomly assigned to 2 treatments with 5 replicates of 8 pigs each. The experimental pigs in the 2 groups were respectively fed with a diet with or without a TZD supplementation (15 mg/kg). In Experiment 2, 80 castrated finishing pigs (Large White${\times}$Landrace, BW = 71.46 kg) were divided into 2 treatments as designed in Experiment 1, moreover, carcass evaluations were performed. The results from Experiment 1 showed that TZD supplementation could significantly decreased the average daily feed intake (ADFI) (p<0.05) during 0 to 28 d, without impairing the average daily gain (ADG) (p>0.05). In Experiment 2, the ADG was significantly increased by TZD supplementation during 14 to 28 d and 0 to 28 d (p<0.05) and the feed:gain ratio (F:G) was significantly decreased by TZD supplementation during 0 to 28 d (p<0.05). Compared with the control group, TZD group had significantly higher serum triglyceride (TG) concentration at 28h and serum high-density lipoprotein (HDL) levels at 14 d (p<0.05). Moreover, there was an apparent improvement in the marbling score (p<0.10) and intramuscular fat (IMF) content (p<0.10) of the longissimus dorsi muscle in pigs treated by TZD supplementation. Real-time RT-PCR analyses demonstrated that pigs of TZD group had higher mRNA abundance of $PPAR{\gamma}$ coactivator 1 (PGC-1) (p<0.05) and fatty acid-binding protein 3 (FABP3) (p<0.05) than pigs of control group. Taken together, these results suggested that dietary TZD supplementation could improve growth performance and increase the IMF content of finishing pigs through regulating the serum parameters and genes mRNA abundance involved in fat metabolism.

• Journal of Korea Water Resources Association
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• v.56 no.1
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• pp.23-34
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• 2023

This study analyzed the bed load transport and channel change on the vegetation zone through laboratory experiments and numerical simulations. To examine the effect of vegetation zone in the laboratory experiment, artificial vegetation zones made of acrylic sticks were installed in the experimental channel, and discharge conditions were adjusted to examine the bed load transport and channel change in the vegetation zone. Next, numerical simulations were performed by applying the same conditions as those of the laboratory experiment to the Nays2D model, a two-dimensional numerical model, and the applicability of the numerical model was examined by comparing the results with the results of the laboratory experiment. Finally, by applying a numerical model, the bed load transport and channel change according to the change in vegetation density were examined. As a result of examining the bed load transport and channel change in the vegetation zone according to the discharge condition change by applying the laboratory experiment and the numerical model, the results of the two application methods were similar. As the discharge increased, bed load from the upper stream was deposited inside the vegetation zone. On the other hand, on the other side of the vegetation zone, the flow was concentrated and erosion occurred. Also, the range of erosion increased in the downstream direction. As a result of examining the bed load transport and channel change according to the change in vegetation density, as the vegetation density increased, the bed load from the upper stream was deposited inside the vegetation zone. On the other hand, due to the increase in vegetation density, the flow was concentrated to the opposite side of the vegetation zone, erosion occurred.

• Environmental Engineering Research
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• v.14 no.3
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• pp.164-169
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• 2009

A powder form of aluminum (hydr)oxides is not suitable in wastewater treatment/filtration systems because of low hydraulic conductivity and large sludge production. In this study, aluminum (hydr)oxide-coated sand (AOCS) was used to remove phosphate from aqueous solution. The properties of AOCS were analyzed using a scanning electron microscopy (SEM) combined with an energy dispersive X-ray spectrometer (EDS) and an X-ray diffractometer (XRD). Kinetic batch, equilibrium batch, and closed-loop column experiments were performed to examine the adsorption of phosphate to AOCS. The XRD pattern indicated that the powder form of aluminum (hydr)oxides coated on AOCS was similar to a low crystalline boehmite. Kinetic batch experiments demonstrated that P adsorption to AOCS reached equilibrium after 24 h of reaction time. The kinetic sorption data were described well by the pseudo second-order kinetic sorption model, which determined the amount of P adsorbed at equilibrium ($q_e$ = 0.118 mg/g) and the pseudo second-order velocity constant (k = 0.0036 g/mg/h) at initial P concentration of 25 mg/L. The equilibrium batch data were fitted well to the Freundlich isotherm model, which quantified the distribution coefficient ($K_F$ = 0.083 L/g), and the Freundlich constant (1/n = 0.339). The closed-loop column experiments showed that the phosphate removal percent decreased from 89.1 to 41.9% with increasing initial pH from 4.82 to 9.53. The adsorption capacity determined from the closed-loop experiment was 0.239 mg/g at initial pH 7.0, which is about two times greater than that ($q_e$ = 0.118 mg/g) from the kinetic batch experiment at the same condition.

• Atmosphere
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• v.18 no.1
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• pp.55-70
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• 2008

The global time slice approach is a transient experiment using high resolution atmosphere-only model with boundary condition from the low resolution globally coupled ocean-atmosphere model. The present study employs this "time slice concept" using ECHAM4 atmosphere-only model at a horizontal resolution of T106 with the lower boundary forcing obtained from a lower-resolution (T42) greenhouse gas + aerosol forcing experiment performed using the ECHO-G/S (ECHAM4/HOPE-G) coupled model. In order to assess the impact of horizontal resolution on simulated East Asian summer monsoon climate, the differences in climate response between the time slice experiments of the present and that of IPCC SRES AR4 participating 21 models including coarser (T30) coupled model are compared. The higher resolution model from time slice experiment in the present climate show successful performance in simulating the northward migration and the location of the maximum rainfall during the rainy season over East Asia, although its rainfall amount was somewhat weak compared to the observation. Based on the present climate simulation, the possible change of East Asian summer monsoon rainfall in the future climate by the IPCC SRES A1B scenario, tends to be increased especially over the eastern part of Japan during July and September. The increase of the precipitation over this region seems to be related with the weakening of northwestern part of North Pacific High and the formation of anticyclonic flow over the south of Yangtze River in the future climate.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.84-88
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• 2002

The effect of dietary xylitol on growth performance and nitrogen retention was studied in male broiler chicks during immunological stimulation. In experiment 1, chicks (10 day of age) were fed a corn-soybean diet containing 10% glucose or 10% xylitol with identical metabolizable energy and crude protein for 14 days. In experiment 2, ten-day-old chicks were fed 10% glucose or 6% xylitol diet for 8 days. During the final 6 days of the experimental periods, a half of birds fed each diet were injected intraperitoneally with 0.5 mg/kg body weight of Escherichia coli lipopolysaccharide (LPS, 0127:B8) on days 1, 3 and 5, and with 250 mg/kg body weight of Sephadex-G50 superfine on days 2 and 4 to stimulate immune system in both experiments. Feeding of the xylitol diets partially prevented the reduction in body weight gain or feed efficiency due to LPS and Sephadex injections, but the glucose diet did not in both the experiments. LPS and Sephadex injections decreased nitrogen retention, whereas the diet containing xylitol partly in experiment 1 and almost completely in experiment 2, prevented the reduction due to immunological stimulation. These results indicate that dietary xylitol probably prevents the reduction in nitrogen retention with growth retardation due to LPS and Sephadex injection. The beneficial effect on nitrogen retention is obtained when chicks are given xylitol 2 days before stimulating the immune system.

• Tunnel and Underground Space
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• v.30 no.3
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• pp.242-255
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• 2020

The numerical simulations of Heater Experiment-D (HE-D) at the Mont Terri rock laboratory in Switzerland were performed to investigate an applicability of FLAC3D to reproduce the coupled thermo-hydro-mechanical (THM) behaviour in Opalinus Clay, as part of the DECOVLEX-2015 project Task B. To investigate the reliability of numerical simulations of the coupled behaviour using FLAC3D code, the simulation results were compared with the observations from the in-situ experiment, such as temperature at 16 sensors, pore pressure at 6 sensors, and strain at 22 measurement points. An anisotropic heat conduction model, fluid flow model, and transversely isotropic elastic model in FLAC3D successfully represented the coupled thermo-hydraulic behaviour in terms of evolution for temperature and pore pressure, however, performance of the models for mechanical behavior is not satisfactory compared with the measured strain.