• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.437-443
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• 2010

To be economically profitable, the poultry industry demands an increase in stocking density, which could adversely affect chicken welfare. The current study was performed to investigate the effect of stocking density on stress-related, heat shock protein genes (HSP70 and HSP90), 3-hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) gene and telomere length in broiler chickens. Seven-day-old broiler chickens were housed at High (0.0578 $m^2$/bird), Standard (0.077 $m^2$/bird) and Low (0.116 $m^2$/bird) stocking densities with 8 replicates each until 35 d of age. The growth performance, such as body weight gain and average daily feed intake, was found to be significantly (p<0.05) higher in the Low density group, but these parameters did not show any difference between the High and Standard groups. Other growth performance, such as feed conversion ratio and final feed intake, showed no difference among the treated groups. The expression levels of HSP70 and HMGCR were found to be elevated with the increase of stocking density. The expression level of these genes was significantly (p<0.05) higher in the High density stocked group compared with the other groups, whereas the expression levels were not significantly different between the Low and Standard groups. The expression levels of HSP90 did not show any significant changes among the treated groups. The telomeric length of the birds housed in High density was reduced significantly (p<0.05) when compared to that of the birds in Low density. These results clearly indicate that birds stocked at high density show physiological adaptive changes indicative of stress at gene transcriptional and telomere levels.

• Progress in Superconductivity and Cryogenics
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• v.5 no.2
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• pp.66-70
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• 2003

Transient magnetic diffusion process in a melt-cast Bi2Sr2CaCu20X(Bi-2212) tube was studied by experimental and numerical analyses. The transient diffusion partial differential equation is transformed into an ordinary differential equation by integral method. The penetration depth of magnetic field into a superconducting tube is obtained by solving the differential equation numerically. The results show that the penetration depth as a function of time which is somewhat different from the results by Bean's critical state model. The reason of the difference between the present results and that of Bean's model is discussed and compared in this paper. This experiment measure the magnetic flux density in the supercondutor after supply direct-current of Bi-2212 rounded by copper coil. This study was discussed of valid of a previous numerical solution which is compared by the penetrate time and the magnetic flux density difference of between the present results and the numerical solution.

• Electrical & Electronic Materials
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• v.9 no.2
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• pp.165-173
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• 1996

We prepared polythiophene and poly(3-methylthiophene) films, known as conducting polymer, by electrochemical method. Polythiophene and poly(3-methylthiophene) films were doped and undoped dopant for the studing the understanding of doping mechanism and possible application to the color change switch. We observed that the anodic, cathodic wave and absorption spectra were slightly changed during doping and undoping process in polythiophene. It shows that doping and undoping process were showed some difference by the appearance and disappearance of polaron and bi-polaron. In the relation of the peak of oxidative current density and potential sweep rate of cyclic voltammograms, the amount of dopant in polythiophene film was homogeneously increased at low scan rate. This also can be applied to the poly(3-methlythiophene).

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.567-573
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• 1997

Photoinduced electron transfer from the charge-transfer excited states of Ru(tpy)(bpy(COOH)₂)$CN^+$, Ru(tpy)(bpy(COOH)₂)$Cl^+$, Ru(tpy)(bpy(COOH)₂)H₂+O², and Ru(tpy)(bqu(COOH)₂)$Cl^+$ to the conduction band of TiO₂ has been studied through photoelectrochemical methods. Ru(tpy)(bpy(COOH)₂)$CN^+$ produced the highest current density and open-circuit photovoltage, whereas Ru(tpy)(bqy(COOH)₂)$Cl^+$ produced the lowest values. A potential barrier was employed to explain the experimental result that the rate of the electron transfer increases with increasing the energy difference between the donor and acceptor. A sensitizer with a high current density yielded a high photovoltage and a high conversion efficiency. The reduction rate of the oxidized sensitizer decreased with the increases in the reduction potential of the sensitizer, resulting in a poor stability of a photoelectrochemical cell.

• Progress in Superconductivity
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• v.1 no.1
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• pp.14-19
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• 1999

Measurements across single grain boundaries in YBCO thin films and bulk bicrystals have been used to demonstrate the influence of grain boundary structure on the critical current carried across the grain boundary. In particular, we show that one role of grain boundary structure is to change the degree of pinning along the boundary, thereby influencing the critical current. This effect can be used to explain the large difference in critical current density across grain boundaries in thin films compared to that for bulk bicrystal. These differences illustrate the distinction between the intrinsic mechanism of coupling across the grain boundary that determines the maximum possible critical current across a boundary and the measured critical current which is limited by dissipation due to the motion of vortices.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.2
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• pp.267-273
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• 2011

The purpose of this study is to examine the changes in bone mineral density in long-stay patients of a geriatric hospital in relation to physical therapy, thereby providing basic data for preventing the onset or deterioration of osteoporosis in inpatients of geriatric hospitals or relevant facilities. The subjects of this study were 133 elderly patients who had been in H geriatric hospital in Yongin-si for more than four years. Their bone mineral density T-scores at admission and those after four years were measured to compare and analyze the changes in bone mineral density in relation to physical therapy. According to the results, the decrease in T-score for the group without physical therapy was greater by .40 than that for the group with physical therapy, indicating a statistically significant difference between the two groups(p<.01). Accordingly, physical therapy proved to be effective in preventing bone mineral density loss and maintaining the current density.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.534-548
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• 1994

The purpose of this study is to observe the corrosion characteristics of seven dental amalgams (CAULK FINE CUT, CAULK SPHERICAL, OPTALLOY II, DISPERSALLOY, HI VERALOY, TYTIN, VALIANT) through the anodic polarization curve obtained by using a potentiostat. After each amalgam alloy and Hg being triturated, the triturated mass was inserted into the cylindrical metal mold, and condensed by hydrolic pressure(160 kg/$cm^2$). Each specimen was removed from the metal mold. 24 hours after condensation, specimens were polished with the emery paper and stored at room temperature for 1 week. The anodic polarization curves were employed to compare the corrosion behaviours of the amalgam in 0.9% saline solution, Fusayama's artificial saliva, and stimulated parotid saliva at $37^{\circ}C$ with 3-electrode potentiostat. After the immersion of specimen in electrolyte for 1 hour, the potential scan was begun. The potential scan range was. -1700m V ~ + 400m V(vs. S. C. E) in the working electrode and the scan rate was 50m V /sec. The results were as follows, 1. The corrosion potential, the potential of anodic current peak, and transpassive potential in the stimulated parotid saliva shifted to more anodic direction than those in saline solution, and the current density in the stimulated parotid saliva was lower than that in saline solution. Those in Fusayama's artificial saliva was similar to those in stimulated parotid saliva. 2. The anodic polarization profiles in Fusayama's artificial saliva and stimulated parotid saliva indicated a region of slow slope current density, which is extending from the corrosion potential to the potential of anodic current peak, but that in 0.9% saline solution indicated no region of slow slope. 3. The corrosion potentials for CAULK FINE CUT, CAULK SPHERICAL, and OPT ALLOY II had the similarity in 0.9% saline solution, Fusayama's artificial saliva and stimulated parotid saliva, but those for high coper amalgam and VALIANT had no similarity. 4. The current density for TYTIN amalgam in stimulated parotid saliva was the lowest among the others. 5. As for current density, there was no significant difference between palladium enriched VALINAT and other high copper amalgams.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.1-6
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• 2007

Two impedance imaging systems of multi-frequency electrical impedance tomography (MFEIT) and magnetic resonance electrical impedance tomography (MREIT) are described. MFEIT utilizes boundary measurements of current-voltage data at multiple frequencies to reconstruct cross-sectional images of a complex conductivity distribution (${\sigma}+i{\omega}{\varepsilon}$) inside the human body. The inverse problem in MFEIT is ill-posed due to the nonlinearity and low sensitivity between the boundary measurement and the complex conductivity. In MFEIT, we therefore focus on time- and frequency-difference imaging with a low spatial resolution and high temporal resolution. Multi-frequency time- and frequency-difference images in the frequency range of 10 Hz to 500 kHz are presented. In MREIT, we use an MRI scanner to measure an internal distribution of induced magnetic flux density subject to an injection current. This internal information enables us to reconstruct cross-sectional images of an internal conductivity distribution with a high spatial resolution. Conductivity image of a postmortem canine brain is presented and it shows a clear contrast between gray and white matters. Clinical applications for imaging the brain, breast, thorax, abdomen, and others are briefly discussed.

• Progress in Superconductivity
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• v.13 no.2
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• pp.90-96
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• 2011

We investigated the properties of artificial pinning centers of YBCO multilayer films in which $Y_2O_3$ and ZnO nanoparticles are uniformly introduced by using the pulsed laser deposition (PLD) technique. $Y_2O_3$ and ZnO nanoparticles were deposited on top of YBCO buffer layer and the density of nanoparticles was controlled by varying the number of nanoparticle layers. YBCO superconducting layers with total thickness of 250 nm were deposited on top of $Y_2O_3$ and ZnO nanoparticles. Based on analyses of the surface morphology, the transition temperature $T_c$, and the critical current density $J_c$, we discussed the difference between the two kinds of nanoparticles as flux pinning centers.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.2
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• pp.105-116
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• 1996

The design and analysis of the transversely fed EMC(electromagnetically coupled) microstrip dipole have been accomplished by using the integral equation and MOM(method of moment)in frequency domain in order to find the current distribution of the dipole. In this study, we proposed the possibilities for design and analysis of EMC micro-strip dipole array antenna by means of calculating the current distribution of each dipole directly using the FDTD(finite difference time domain) method. In this case, we applied the formulation which is the finite difference expression of the Maxwell's integral equation. From the current distribution of each dipole, we calculated the far field electric component and showed that the calculation process and running time was reduced with respect to the method which calculates the radiation field with surface electric and magnetic current density.