폴리카프로락톤(PCL)에 NaCl을 혼합한 용액을 블레이드법에 의하여 막형태로 제조한 후 NaCl을 추출하는 염출 법을 이용하여 조직공학적으로 사용할 3차원 다공망을 갖는 멤브레인 형태의 지지체를 제조하였다. 본 연구에서는 성형된 멤 브레인의 건조조건과, NaCl 입자의 크기, NaCl의 혼합량을 각각 다르게 하여 제조하였다. 별도로 제작한 고분자용액 공급장 치를 이용하여 PCL/클로로포름(CHCl3) 용액에 NaCl 입자가 균일하게 혼합된 용액을 유리판에 분주하여 필름 어플리케이터 를 사용하여 블레이드법에 의한 멤브레인을 제조하였다. 멤브레인 지지체에는 NaCl 입자에 의한 거대기공과 거대기공을 이 루는 구조벽에서는 CHCl3의 증발에 의한 미세기공이 함께 복합적으로 상호 연결되어 형성되었다.
Cu(In,Ga)Se2(CIGS) photovoltaic thin films were electrodeposited on Mo/glass substrates with an aqueous solution containing 2 mM CuCl2, 8 mM InCl3, 20 mM GaCl3 and 8mM H2SeO3 at the electrodeposition potential of -0.6 to -1.0 V(SCE) and pH of 1.8. The best chemical composition of Cu1.05In0.8Ga0.13Se2 was found to be achieved at -0.7 V(SCE). The precursor Cu-In-Ga-Se films were annealed for crystallization to chalcopyrite structure at temperatures of 100-500˚C under Ar gas atmosphere. The chemical compositions, microstructures, surface morphologies, and crystallographic structures of the annealed films were analyzed by EPMA, FE-SEM, AFM, and XRD, respectively. The precursor Cu-In-Ga-Se grains were grown sparsely on the Mo-back contact and also had very rough surfaces. However, after annealing treatment beginning at 200˚C, the empty spaces between grains were removed and the grains showed well developed columnar shapes with smooth surfaces. The precursor Cu-In-Ga-Se films were also annealed at the temperature of 500˚C for 60 min under Se gas atmosphere to suppress the Se volatilization. The Se amount on the CIGS film after selenization annealing increased above the Se amount of the electrodeposited state and the MoSe2 phase occurred, resulting from the diffusion of Se through the CIGS film and interaction with Mo back electrode. However, the selenization-annealed films showed higher crystallinity values than did the films annealed under Ar atmosphere with a chemical composition closer to that of the electrodeposited state.
Polymer gel implant for soft tissue augment is demanded biological safety properties. This study is designed process and equipment producing for obtain micro bead using the hyaluronic acid water solution. This equipment is composed of cooling pipe, air pump, dispenser and process is consecutive/simple for preservation from environmental contamination. Besides, without difficulty remove the residual agent after crosslink. We evaluate to in vitro cytotoxicity test for verification of hyaluronic acid gel obtained by this equipment and process. This product is "non cytotoxcity" from the result of evaluation cytotoxcity test.
Since the 1990s, the second generation of Zirconium alloys containing main alloy compositions of Nb, Sn and Fe have been used as a replacement of Zircaloy-4 (Zr-Sn-Fe-Cr), a first-generation Zirconium alloy, to meet severe and rigorous reactor operating conditions characterized by high-burn-up, high-power and high-pH operations. In this study, the mechanical properties and creep behaviors of Zr-Sn-Fe-Cr and Zr-Nb-Sn-Fe alloys were investigated in a temperature range of 450~500˚C and in a stress range of 80~150 MPa. The mechanical testing results indicate that the yield and tensile strengths of the Zr-Nb-Sn-Fe alloy are slightly higher compared to those of Zr-Sn-Fe-Cr. This can be explained by the second phase strengthening of the β-Nb precipitates. The creep test results indicate that the stress exponent for the steady-state creep rate decreases with the increase in the applied stress. However, the stress exponent of the Zr-Sn-Fe-Cr alloy is lower than that of the Zr-Nb-Sn-Fe alloy in a relatively high stress range, whereas the creep activation energy of the former is slightly higher than that of the latter. This can be explained by the dynamic deformation aging effect caused by the interaction of dislocations with Sn substitutional atoms. A higher Sn content leads to a lower stress exponent value and higher creep activation energy.
TiC 입자를 강화재로 한 AI금속기지 복합재료를 액상교반법으로 제조하는데 따른 제조조건과 물성특성과의 관계를 조사하였다. TiC 입자는 중량비 10%를 첨가하였으며, 젖음성을 향상시키기 위하여 1.5wt%의 Mg을 첨가하였다. TiC입자 첨가에 의하여 내마모 특성, 인장강도, 경도 등이 증가 되었으나 과도한 교반은 기계적 특성을 저하시켰다. 본 실험조건에서 교반 속도의 최적조건은 500rpm이었다. Wetting agent로서 첨가한 Mg은 기지에 고루 분산하였다.