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Ni alloys are used as the prominent industrial material for heat-resistance and corrosion-resistance. Out of them, Inconel has excellent properties for high-temperature heat-resistant equipment as an excellent material for equipment such as ultrahigh-temperature electric furnace and or boiler. However, Ni alloys used in various areas contain high-priced metals such as Ta, Nb, or Re and their use have been limited to industrial sector so far due to the price incompetence. In this study, the alloy Ni-28Cr-4Mo-2Ti was designed by electronic state calculation by replacing the expensive material of Ta and Nb in Inconel 625 with Ti. In order to compare the corrosion properties, they were intentionally corroded in a furnace at 500 °C for 3 months and potentiodynamic polarization method was used to check the corrosion rate. The validity of the results was also confirmed by using the values of atomic radius and electronegativity. As a result, it was confirmed that the newly designed alloy had superior corrosion resistance at higher temperature than Inconel 625.

The separation of circulating tumor cells (CTCs) from the blood of cancer patients with high sensitivity is an essential technique for selecting chemotherapeutic agents at a patient-by-patient level. Recently, various research groups have reported a nanostructure-based platform for rare cell capture due to its high surface area and 3D nanotopographic features. However, evaluation of capture sensitivity based on chemical modification of the nanostructure surface has not yet been performed. Here, we evaluated the capture sensitivity for CTCs from the blood of three patients diagnosed with stage IV metastatic breast cancer by using the following three platforms: streptavidin-conjugated silicon nanowire (STR-SiNW), poly-l-lysine-coated silicon nanowire (PLL-SiNW), and poly-l-lysine-coated glass (PLL-glass). The number of evaluated CTCs on STR-SiNW, PLL-SiNW, and PLL-glass were 16.2 ± 5.5 cells, 7.3 ± 2.9 cells, and 4.7 ± 1.5 cells, respectively, per 0.5 ml. Therefore, we suggest that the STR-SiNW platform is highly adaptable for the quantitative evaluation of CTCs from the blood of cancer patients in the clinical setting.

In this work, we found the characteristics of an antibacterial TiAgN thin film coated on the pure titanium specimen via the physical vapor deposition process (PVD). TiAgN thin films were coated using TiAg alloy targets by arc ion plating method. Changing the process parameters, the surface analysis of TiAgN thin film was observed by FE-SEM and the force of adhesion was measured with Scratch Tester. The proliferation of human gingival fibroblast (HGF) cells was examined by XTT test assay and the antibacterial properties were investigated by culturing Streptococus Mutans (KCTC 3065) using paper disk techniques. At the result of experiment, cytotoxic effects were not found and the antibacterial effects against Streptococus Mutans were appeared over 5 wt% TiAgN specimens.

The surface structure and electrical properties of titanium-doped indium oxide (ITiO) films prepared by RF magnetron sputtering were investigated. The doping concentration of TiO2 in the In2O3 target was changed from 1.0 wt.% to 10.0 wt.% with increments of 1.0 wt.%. At a Ti content of 5.0 wt.%, the optimum growth conditions were achieved. The finest value of hall mobility, carrier concentration, and resistivity of the deposited film reached 47.03 cm2Ns, 1.148 x 10(21) cm-3 and 1.14 x 10(-4) Ωcm, respectively. Then the transmittance was achieved up to 82% at 570 nm. The peaks of the XRD spectra became more intense and sharp as the Ti concentration increased up to 2.5 wt.% but a higher Ti content of 10.0 wt.% retarded a growth of In2O3 grains. The surface roughness of the films by examination of surface morphology using AFM also rose with increase of Ti doping concentration.

Nanostructured surfaces emerge as a new class of material for capture and separation of cell populations including primary immune cells and disseminating rare tumor cells, but the underlying mechanism remains elusive. Although it has been speculated that nanoscale topological structures on cell surface are involved in the cell capture process, there are no studies that systematically analyze the relation between cell surface structures and the capture efficiency. Here we report on the first mechanistic study by quantifying the morphological parameters of cell surface nanoprotrusions, including filopodia, lamellipodia, and microvilli in the early stage of cell capture (< 20 min) in correlation to the efficiency of separating primary T lymphocytes. This was conducted by using a set of nanohole arrays (NHAs) with varying hole and pitch sizes. Our results showed that the formation of filopodia (e.g., width of filopodia and the average number of the filopodial filaments per cell) depends on the feature size of the nanostructures and the cell separation efficiency is strongly correlated to the number of filopodial fibers, suggesting a possible role of early stage mechanosensing and cell spreading in determining the efficiency of cell capture. In contrast, the length of filopodial filaments was less significantly correlated to the cell capture efficiency and the nanostructure dimensions of the NHAs. This is the first mechanistic study on nanostructure-based immune cell capture and provides new insights to not only the biology of cell-nanomaterial interaction but also the design of new rare cell capture technologies with improved efficiency and specificity.

Nanoporous Ti metal film electrodes for use as photoanodes in dye-sensitized solar cells (DSSCs) were deposited directly on the nanoporous TiO2 layer using the two-step RF magnetron sputtering technique. The Ti film electrode replaces the transparent conducting oxide (TCO) layer. The effect of substrate heating during the deposition of the Ti film was studied to improve the porosity and columnar array of the film pores and the resulting cell efficiency. The porous Ti layer (-41 microm) with low sheet resistance (-1.7 omega/sq) was obtained by deposition at 250 degrees C. The porous Ti layer collects electrons from the TiO2 layer and allows the diffusion of I-/I3(-) through the holes. The DSSC efficiency (eta) using porous Ti layers with highly columnar structures was measured with the highest conversion efficiency of -5.77%; the other photovoltaic properties were ff: 0.76, V(oc): 0.72 V, and J(sc): 10.6 mA/cm2.

Transparent conductive In(2-x)Sn(x)O3 (ITO) and In(2-x)Ti(x)O3 (ITiO) films were prepared via RF magnetron sputtering on soda-lime glass substrates at 300 degrees C and investigated with respect to their photoelectric conversion performance compared with the commercial F:SnO2 (FTO) glass. The near infrared ray transmittance of ITiO was highest for wavelengths over 1000 nm compared with those of ITO and FTO. Photoelectrochemical cells (PECs) were fabricated using ITiO film, ITO film, and FTO glass. The photoelectric conversion efficiency (eta) of the PECs samples using ITiO was 5.64%, whereas 2.73% was obtained from the PEC samples with ITO, both at 100 mW/cm2 light intensity. The impedance measurement was also used to explain the electrochemical performance of the PECs with various TCO glasses.

We investigated the imidization of a polyimide (PI) and the formation of Cu nanoparticles in a PI film by curinga precursor of PI (polyamic acid (PAA) dissolved in n-methyl-2-pyrrolidinone) in a reducing atmosphere in the rapid thermal annealing (RTA) system. A Cu film was deposited onto the SiO2/Si substrate, and the PAA was spin-coated onto the Cu film. After the PAA reacted with the Cu film, soft-baking was performed to evaporate the solvent. Finally, the PAA was imidized to PI at 450 degrees C by curing in a reducing atmosphere with the RTA. Fourier transform infrared spectroscopy showed that the PAA was successfully imidized by the RTA. X-ray diffraction patterns revealed that Cu nanoparticles formed by RTA curing at 450 degrees C for 5 minutes in a reducing atmosphere, and transmission electron microscopy showed that Cu nanoparticles about 6.5 nm in size were uniformly dispersed in the PI film. Curing by RTA is an attractive method because it takes only a few minutes.

Nanoporous Ti-metal film electrode was fabricated by radio frequency (rf) magnetron sputtering technique on nanoporous TiO2 layer prepared by sol-gel combustion method and investigated with respect to its photo-anode properties of TCO-less DSCs. The porous Ti layer (approximately 1 microm) with low sheet resistance (approximately 17 Omega/sq.) can collect electrons from the TiO2 layer and allows the ionic diffusion of I(-)/I(3-) through the hole. The porous Ti layer with highly ordered columnar structure prepared by 8 mTorr sputtering shows the good impedance characteristics. The efficiency of prepared TCO-less DSCs sample is about 4.83% (ff: 0.6, Voc: 0.65 V, Jsc: 11.2 mA/cm2).

Cu and Cu2O nanoparticles were fabricated in polyimide by curing the stacked polyamic acid/Cu/polyamic acid on Si wafer and post heat treatment. Nanoparticle distribution in polyimide (a monolayer of vertically aligned nanoparticles or the randomly dispersed nanoparticles) can be controlled by changing the reactivity of Cu with PAA and curing atmosphere. About 6-7 nm sized Cu or Cu2O nanoparticles were observed in the polyimide film. The capacitance-voltage curves were measured with Al/particles in polyimide/p-Si(100) specimens at 300 K, and the capacitance hystereses were observed at different sweep voltage ranges, which indicates that Cu2O or Cu nanoparticles can be utilized in next generation flash memories.

NO and SO2 removal by dielectric barrier discharge-photocatalyst (DBD-P) hybrid process was examined for various conditions of process variables. Alumina beads were coated with TiO2 thin film by a rotating cylindrical PCVD reactor and they were packed inside the cylindrical reactor. The NO and SO2 removal efficiencies can be enhanced by using a combination of dielectric barrier discharge and photodegradation by TiO2. The stronger the applied voltage is, the higher the pulse frequency is, or the longer the gas residence time is, the higher the NO and SO2 removal efficiencies become. By applying additional photocatalytic effect, NO removal efficiency increased more significantly than SO2 removal efficiency, because SO2 removal efficiency was already high by dielectric barrier discharge only. In this study, we found that the alumina beads coated with TiO2 thin film by a rotating cylindrical PCVD reactor could be used effectively to remove NO and SO2 by DBD-P hybrid process.

We investigated the formation of CuO or Cu2O nanoparticles in the thick polyimide films by oxidizing Cu nanoparticles at various temperatures during the post heat-treatment. Cu nanoparticles of 4-5 nm in diameter were initially formed in the polyimide film by the reaction between a Cu film and a polyimide precursor, polyamic acid, and a following thermal curing in a reducing atmosphere. After the subsequent post heat-treatments in oxidizing atmospheres, X-ray diffraction patterns revealed that initial metallic Cu nanoparticles were transformed to Cu2O or CuO nanoparticles depending on the temperature during the post heat-treatment. Cu nanoparticles were oxidized to Cu2O during the post heat-treatment at low temperature while Cu nanoparticles were oxidized to CuO during the post heat-treatment at high temperature. Cross-sectional TEM studies showed that about 4.7 nm sized Cu2O nanoparticles or 4.7-5.2 nm sized CuO nanoparticles were fabricated in a thick polyimide film depending on the post heat-treatment condition. In the optical absorption measurements, the absorption peak from surface plasmon resonance of Cu nanoparticles disappeared during the post heat-treatment in an oxidizing atmosphere.

We report on the effect of surface passivation on the electrical characteristics of multi-channel ZnO nanowire field-effect transistors (FETs). Surface passivation was performed using a SiO2 layer on ZnO nanowires. Multi-channel FETs were prepared by assembling as synthesized ZnO nanowires on a SiO2/Si substrate using an alternating current (AC) dielectrophoresis (DEP) technique. We observed that surface passivation with a SiO2 layer on ZnO nanowires was significantly affected by electrical characteristics of multi-channel ZnO nanowire FETs such as the threshold voltage and transconductance.

We calculated the concentration profiles of important chemical species for TiO2 thin film growth on the glass beads in the TTIP + O2 plasmas and compared the predicted growth rates of thin films with the experimental measurements. The film thickness profile depends on the concentration profile of TiO(OC3H7)3 precursors in the gas phase because TiO(OC3H7)3 is the main precursor of the thin film. The TTIP concentration decreases with time, while the TiO(OC3H7)3 concentration increases, and they reach the steady state about 2 approximately 3 sec. The growth rate of TiO2 film predicted in this study was 9.2 nm/min and is in good agreements with the experimental result of 10.5 nm/min under the same process conditions. This study suggests that a uniform TiO2 thin film on particles can be obtained by using a rotating cylindrical PCVD reactor.

We analyzed TiO2 thin film growth on glass particles in a rotating cylindrical plasma chemical vapor deposition (PCVD) reactor and numerically investigated the effects of several process variables on the film growth. An increase in titanium tetra-isopropoxide (TTIP) or O2 partial pressure can enhance the film growth rate on the particles because the concentration of TiO(x), which is the main precursor for thin film growth, becomes higher in the reactor. As the particle diameter decreases, the TiO(x) concentration increases and the thin film on the particles grows more quickly. The neutral-radical reaction between TTIP and O radicals for TiO(x) generation in TTIP + O2 plasmas can be important to enhance the thin film growth rate on the particles. The growth rate of TiO2 film predicted in this study was 1 approximately 20 nm/min, which is in good agreement with the published experimental results. This study suggests that a uniform TiO2 thin film on particles can be obtained by using a rotating cylindrical PCVD reactor.

The computational analysis was developed to illustrate the gas temperature and velocity profiles in the oxy-methane diffusion flame reactor during the formation of TiO2 nanoparticles and the collection of the TiO2 nanoparticles by filter. The computational simulation shows that the increase in gas temperature and velocity is significantly affected by the increase in CH4 flow rate. The particle trajectory was calculated by using the model, which concerns the effects of thermophoretic force and gas velocity on the particle movement. The particles starting from different initial positions in radial direction will move in different trajectories. The particles following different trajectories have different temperature histories and also residence times in the gas phase. As the particles start at the initial position of the reactor which is further away from the central axis, they spend longer time in the gas phase and deposit on the higher position of filter. For particles starting at the initial position of the reactor which is further than 0.5 cm from the central axis, they move to deposit on the pyrex tube instead of filter. As the CH4 flow rate increases, the particles move further from the central axis, but it takes a shorter time for the particles to deposit on the filter. The particles synthesized at a higher CH4 flow rate show significantly higher temperature history than those particles synthesized at a lower CH4 flow rate. The temperature histories of particles in diffusion flame reactor can be quite important information to control the properties of TiO2 nanoparticles.

Temperature and velocity profiles were simulated by a computational fluid dynamics method for the synthesis of TiO2 nanoparticles by a diffusion flame reactor and also for the collection of the TiO2 nanoparticles by a filter. Computational grids were created by GAMBIT and all governing equations for momentum, energy and mass balances were solved by FLUENT code. The effects of O2 flow rate on the fluid dynamics and particle trajectories are illustrated. An increase in O2 flow rate reduces the flame temperature but significantly enhances the gas velocity. The particle trajectory differs according to the starting position. The effect of O2 flow rate on the particle trajectory can be seen clearly at the starting position r(0) = 0.2 cm from the central axis. The particles at higher O2 flow rate move closer to the central axis and deposit earlier on the filter than the particles at lower O2 flow rate. The particles starting at r(0) = 0.4 cm at higher O2 flow rate move further away from the central axis and deposit at a higher position on the filter. Information on gas temperature, velocity profiles and particle trajectories can be quite useful in designing a diffusion flame reactor to synthesize high-performance TiO2 nanoparticles.

Nanoparticles of Cu or Cu oxide dispersed in a polyimide (PI) film were fabricated by reaction of polyamic acid with a thin Cu film during imidization. In this paper, the thermal stability of the Cu or Cu oxide nanoparticles was investigated under various atmospheres. The PI/nanoparticle composites were heat-treated at 140 degrees C and 250 degrees C in air, N2, Ar, and 5% H2 atmospheres. Nanoparticles in the PI film were characterized by UV-VIS spectroscopy and transmission electron microscopy. The optical absorption peaks originating from Cu or Cu2O nanoparticles were changed by heat-treatment in different atmospheres. When Cu nanoparticles were oxidized by heat-treatment in air, the surface plasmon resonance (SPR) peak originating from the Cu nanoparticles disappeared. The quantum confined absorption peak of Cu2O was not affected by heat-treatment in N2 or Ar. Cu2O nanoparticles were reduced by heat-treatment at 250 degrees C in 5% H2 atmosphere and a new SPR peak appeared. Our results show that Cu nanoparticles are easily oxidized and highly dense Cu nanoparticles can be formed by reducing Cu2O nanoparticles.

We report on the dielectrophoresis (DEP) characterization of single crystalline zinc oxide (ZnO) nanowires with variations of the AC electric field and frequency. The alignment yield rate of ZnO nanowires in the gap over the 200 metal electrodes increased with increasing AC electric field and also changed by the applying frequency. Moreover, we demonstrated that the DEP prepared multi-ZnO nanowires field-effect transistors (FETs) exhibited excellent performance with a transconductance of approximately 3 muS and a high drain current of approximately 2.7 x 10(-6) A (V(DS) = 5 V, V(G) = 20 V).