• Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.1-11
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• 2022

Catfish is one of the most important freshwater fish farming commodities in Indonesia. Higher catfish production can be achieved by cultivating transgenic catfish carrying the growth hormone (GH) gene of African catfish (Clarias gariepinus GH, CgGH). This research focuses on analysis of the presence of the CgGH gene in transgenic G₁, G₂, and G₃ mutiara catfish broodstock, as an indication of stable CgGH inheritance. CgGH gene was isolated using the RNeasy mini kit and RT-PCR. RT-PCR revealed amplicons measuring approximately 600 bp in transgenic G₀, G₁, G₂, and G₃ mutiara catfish. The CgGH consensus sequence similarities ranged from 93.76% to 97.06%, with four functional domain sites (somatotropin-1, somatotropin-2, four α-helix, N-glycosylation, four cysteine residues) of fish GH proteins. The functional domains of fish GH proteins are conserved in G₁, G₂, and G₃ and indicate stable exogenous GH inheritance to produce transgenic catfish strains in each generation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.5
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• pp.298-302
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• 2016

In this work, $LiMn_2O_4$ and $LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ cathode materials are mixed by some specific ratios to enhance the practical capacity, energy density and cycle performance of battery. At present, the most used cathode material in lithium ion batteries for EVs is spinel structure-type $LiMn_2O_4$. $LiMn_2O_4$ has advantages of high average voltage, excellent safety, environmental friendliness, and low cost. However, due to the low rechargeable capacity (120 mAh/g), it can not meet the requirement of high energy density for the EVs, resulting in limiting its development. The battery of $LiMn_2O_4-LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ (50:50 wt%) mixed cathode delivers a energy density of 483.5 mWh/g at a current rate of 1.0 C. The accumulated capacity from $1^{st}$ to 150th cycles was 18.1 Ah/g when the battery is cycled at a current rate of 1.0 C in voltage range of 3.2~4.3 V.

• Journal of Life Science
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• v.26 no.2
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• pp.190-197
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• 2016

Aflatoxin M₁ can be produced in cow’s milk when cows eat contaminated produce. Milk is a major source of food for infants and for children who have a weak level of immunity, and the detection of Aflatoxin M₁ for risk assessment is necessary in order to reduce the amount of it in milk. In this study, the Aflatoxin M₁ level was monitored for one year in raw milk samples obtained from Chungnam Province, Korea. The milk samples were divided into three categories: 1. milk samples from a standard general farm, 2. milk samples from a HACCP controlled farm, and 3. milk samples from the supply of Aflatoxin M₁ reduced fodder. The average concentrations of Aflatoxin M₁ in milk were 0.023±0.005 ug/l for the standard general farm, 0.017±0.004 ug/l for the HACCP controlled farm, and 0.013±0.003 ug/l for the supply of Aflatoxin M₁ reduction fodder. Milk collected from the supply of Aflatoxin M₁ reduction fodder had the lowest level of Aflatoxin M₁. However, when efficiency and economic aspects are considered the most effective way of reducting Aflatoxin M₁, could be taking milk from the HACCP controlled farm and implementing good feed management. Institutional support from the government, careful management of dairy farming, and a strict farm sanitation program are required in order to lower the level of Aflatoxin M₁ in milk.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1065-1068
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• 2008

• Journal of the Chungcheong Mathematical Society
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• v.33 no.2
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• pp.227-236
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• 2020

A set {a₁, a₂,_…, a_m} of positive integers is called Diophantine m-tuple if a_ia_j+1 is a perfect square for all 1 ≤ i < j ≤ m. In this paper, we find the structure of torsion group of elliptic curve E_k constructed by Diophantine triple, and find all integer points on E_k under assumption that rank(E_k(ℚ)) = 1.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.3
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• pp.227-231
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• 2008

In this study, in order to improve the electrical properties of low temperature sintering piezoelectric ceramics, $[0.05Pb(Zn_{1/2}W_{1/2})-0.07Pb(Mn_{1/3}Nb_{2/3})-0.088Pb(Zr_{0.48}Ti_{0.52})]O_3$(abbreviated as PZW-PMN-PZT) ceramic systems were fabricated using $Bi_2O_3$, CuO and $Li_2CO_3$ as sintering aids and then their piezoelectric and dielectric properties were investigated according to the amount of $Li_2CO_3$ and post-annealing process. Post-annealing process enhanced all physical properties except for mechanical quality factor (Qm). 0.2 wt% $Li_2CO_3$ added and post-annealed specimen showed the excellent values suitable for low loss piezoelectric actuator application as follow: the density = 7.86 $g/cm^3$ electromechanical coupling factor (kp) = 0.575, piezoelectric constant $d_{33}$ = 370 pC/N, dielectric constant ($\varepsilon_r$) = 1546, and mechanical quality factor (Qm) = 1161, respectively.

• Journal of IKEEE
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• v.25 no.3
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• pp.501-505
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• 2021

In this study, we fabricated amorphous indium-tin-gallium-zinc-oxide thin-film transistors (a-ITGZO TFTs) with gate dielectrics of HfO₂ and the mixed layers of HfO₂ and Al₂O₃, and investigated the effect of gate dielectric on electrical characteristics of a-ITGZO TFTs. When only HfO₂ was used as the gate dielectric, the mobility and subthreshold swing (SS) were 32.3 cm²/Vs and 206 mV/dec. For the a-ITGZO TFTs with gate dielectric made of HfO₂ and Al₂O (2:1, 1:1), the mobilities and SS were 26.4 cm²/Vs (2:1), 16.8 cm²/Vs(1:1), 160 mV/dec (2:1) and 173 mV/dec (1:1). On the other hand, the hysteresis window shown in transfer curves of the a-ITGZO TFTs was lessened from 0.60 to 0.09 V by the increase of Al₂O₃ ratio in gate dielectric, indicating that the interface trap density between the gate dielectric and channel layer decreases due to Al₂O₃.

• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.757-761
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• 2019

The catalytic yields of POM to hydrogen over M(1)-Ni(5)/AlCeO₃ (M = La, Ce, Y) were investigated using a fixed bed flow reactor under atmosphere. The crystal phase behavior of reduced La(1)-Ni(5)/AlCeO₃ catalysts before and after the reaction were studied via XRD analysis. FESEM and EDS analyses were further performed to show the uniformed distribution of La, Ni, and Ce metal particles on the catalyst surface. XPS results showed O^2-, O₂^2- species and metal ions such as Ce³⁺, Ce⁴⁺, La³⁺ and Ni²⁺ etc. were on the catalyst surface. When 1 wt% of La was added to Ni(5)/AlCeO₃ catalyst, Ni2p_3/2 and Ce3d_5/2 increased 52.7 and 6.3%, respectively. The yield of hydrogen on the La(1)-Ni(5)/AlCeO₃ catalyst was 89.1%, which was much better than that of M(1)-Ni(5)/AlCeO₃ (M = Ce, Y). As Ce⁴⁺ ions of CeO₂ produced by the reaction of AlCeO₃ with oxygen were substitute to La³⁺, it made oxygen vacancies in the lattice and further improved the hydrogen yield by increasing the dispersion of Ni atoms with strong metal-support interaction (SMSI) effect.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4642-4646
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• 2023

The Tb³⁺ or Eu³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor were fabricated by funace at 1500 ℃ for 12 h using a solid state reaction. The XRD (X-ray diffraction_Panalytical X'Pert Pro) and FE-SEM (field emission scanning electron microscope) are measured to confirm the crystalline structure and surface morphology of the phosphor. The Tb³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor emits the lights in 470~650 nm wavelength range due to transitions from ⁵D₄ to ⁷F_j. Therefore, it shows the green region in the CIE chromaticity diagram under both UV and X-rays excitations. The Eu³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor emits the lights in 550~750 nm wavelength range because of ⁵D_i to ⁷F_j. The emission is confirmed to be in the red region using the CIE chromaticity diagram. The Tb³⁺ or Eu³⁺-doped Lu₂Gd₁Ga₂Al₃O₁₂ phosphor shows the characteristic f-f transition with a long decay time, which is about several milliseconds. They have the high efficiency of light emission for X-ray because of their high effective Z number (Z_eff = 58.5) and density. Therefore, they are very much promising phosphors for X-ray imaging application in medical fields.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.238-245
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• 2023

0.75(Bi_1/2Na_1/2)TiO₃-0.25SrTiO₃ (BNT-25ST) ceramics with high densities were successfully prepared at a sintering temperature of 1,000℃ by adding a mixture of 1 mol% CuO and 0.5 mol% Na₂CO₃ or 0.5 mol% CuO and 0.25 mol% Na₂CO₃. Double polarization-electric field (P-E) hysteresis curves and sprout-shaped bipolar strain-electric field (S-E) hysteresis curves with small negative strains were observed in the pristine and CuO-added BNT-25ST ceramics whereas the Na₂CO₃-added sample showed similar P-E and S-E curves to a typical ferroelectric. The pristine BNT-25ST ceramics showed an extremely large strain and a large-signal piezoelectric strain constant (d₃₃^*): 0.287 % at 80 kV/cm and 850 pm/V at 20 kV/cm. Similar values, 0.248 % at 80 kV/cm and 655 pm/V at 20 kV/cm, were obtained in the CuO-added sample. However, the pristine and CuO-added samples showed large hysteresis in unipolar S-E curves at an electric field of less than 20 kV/cm. The Na₂CO₃-added sample showed smaller values of the strain and d₃₃^* but displayed a linear change and small hysteresis in the unipolar S-E curve. The co-added sample with CuO and Na₂CO₃ displayed intermediate P-E and S-E hysteresis curves.