• Journal of Powder Materials
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• v.9 no.1
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• pp.25-31
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• 2002

The efects of mechanical aloying conditions and the type of reducing agent on the solid state reductionof haematite $Fe_2O_3$ have been investigated at room temperature. Aluminium titanium zinc and copper were used as reducing agent. Nanocomposites of metal-oxide in which oxide particles with nano size were dispersed in Fe matrix were obtained by mechanical alloying of $Fe_2O_3$ with aluminium and titanium respectively However the reduction of $Fe_2O_3$ by coppe was not occurred Composite materials of iron with $Al_2O_3$ and $TiO_2$ were obtained from the system of $Fe_2O_3-Al$ and $Fe_2O_3-Ti$ after ball milling for 20 hrs and 30 hrs respectively. And the system of $Fe_2O_3-Zn$ resulted in the formationof FeO with ZnO after ball milling of 120 hrs. The final grain sizes of iron estimated by X-ray diffraction line-width measurement were in the ranges of 24~33 nm.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E4
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• pp.157-168
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• 2003

This study evaluated the technical feasibility of the application of titanium oxide (TiO$_2$) photocatalysis for the removal of VOCs in low ppb concentrations commonly associated with non -occupational indoor air quality issues. A series of experiments were conducted to evaluate four parameters (relative humidity (RH), hydraulic diameter (HD), photocatalytic oxidation (PCO) reactor material (RM), and inlet port size (IPS) of PCO reactor) for the PCO destruction efficiencies of the selected target VOCs. None of the target VOCs presented significant dependency on the RH, which is inconsistent with a few previous studies. However, it is noted that the three parameters (HD, RM and IPS) should be considered for better VOCs removal efficiencies for the application of TiO$_2$ photocatalytic technology for cleansing non -occupational indoor air. The PCO destruction of VOCs at concentrations associated with non-occupational indoor air quality issues can be up to nearly 100％. The amount of CO generated during PCO would be negligible in comparison to the indoor CO levels. These results can make the PCO reactor an important tool in the effort to improve non-occupational indoor air quality.

• Journal of the Korean Vacuum Society
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• v.11 no.3
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• pp.141-150
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• 2002

Titanium oxide thin films were deposited by DC reactive magnetron sputtering(RMS) with Ar ion-beam assistance using end-Hall ion source at low oxygen partial pressure and long target-to-substrate distance. The optical and structural properties of deposited films were investigated by the measurement of measured transmittance and reflectance, atomic force microscope(AFM), and X-ray diffraction(XRD). The results show that the Ax ion-beam assisted RMS for titanium oxide thin films induces the higher packing density, lower absorption, and smoother surface than the conventional RMS, suggesting that it can be employed in deposition of optical dielectric coatings.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.69-77
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• 2013

The purpose of this study is to improve the properties of epoxy resin using the big-sized titanium oxide nanoparticles. The effects of particle weight fraction and shape of sample on the thermal and mechanical properties in titanium oxide reinforced epoxy resin has been investigated. In addition, the effect of particle dispersion situation on the mechanical properties of nanocomposites has been studied. As a result, the Tg was almost same regardless of the content of nanoparticles. Storage modulus increased up to the content of 3wt% particles and then decreased. Tensile strength and modulus of film-shaped sample with 1wt% was higher than the one of pure epoxy, while other composites were not. The tensile strength of dogbone-shaped sample with 1wt% was only higher than the one of pure epoxy, while other composites were lower than the one of pure epoxy. Tensile modulus of dogbone-shaped samples increased with the content of particles.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.3
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• pp.119-123
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• 2005

Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. Li$_{4}$Ti$_{5}$O$_{12}$ based spinel-framework structures are of great interest material for lithium-ion batteries. We describe here Li$_{4}$Ti$_{5}$O$_{12}$ a zero-strain insertion material was prepared by novel sol-gel method and by high energy ball milling (HEBM) of precursor to from nanocrystalline phases. According to the X-ray diffraction and scanning electron microscopy analysis, uniformly distributed Li$_{4}$ Ti$_{5}$O$_{12}$ particles with grain sizes of 100nm were synthesized. Lithium cells, consisting of Li$_{4}$ Ti$_{5}$O$_{12}$ anode and lithium cathode showed the 173 mAh/g in the range of 1.0 $\~$ 3.0 V. Furthermore, the crystalline structure of Li$_{4}$ Ti$_{5}$O$_{12}$ didn't transform during the lithium intercalation and deintercalation process.

• International Journal of Ocean System Engineering
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• v.3 no.2
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• pp.102-110
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• 2013

The purpose of this study was to improve the properties of epoxy resin using titanium oxide nanoparticles. The effects of particle weight fraction, dispersion agent, and curing agents with different molecular weights on the thermal and mechanical properties of titanium-oxide-reinforced epoxy resin were investigated. In addition, the effect of the particle dispersion condition on the mechanical properties of nanocomposites was studied. As a result, it was found that the glass transition temperature of film-shaped nanocomposites decreased with an in-crease in the nanoparticle content. Because nanoparticles interrupted the cross linkage between the epoxy resin and the amine curing agent, the cross-link density of the epoxy became lower and led to a decrease in $T_g$ in the nanocompo-sites. The tensile strength and modulus in film-shaped nanocomposites also increased with the particles content. But in the case of dog-bone-shaped nanocomposites, the values were not similar to the trend for the film-shaped nanocompo-sites. This was probably a result of the different nanoparticles dispersions in the epoxy resins resulting from the respective-thicknesses of the film and dog-bone-shaped samples.

• Journal of Powder Materials
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• v.29 no.4
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• pp.297-302
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• 2022

This study compares the characteristics of a compact TiO₂ (c-TiO₂) powdery film, which is used as the electron transport layer (ETL) of perovskite solar cells, based on the manufacturing method. Additionally, its efficiency is measured by applying it to a carbon electrode solar cell. Spin-coating and spray methods are compared, and spray-based c-TiO₂ exhibits superior optical properties. Furthermore, surface analysis by scanning electron microscopy (SEM) and atomic force microscopy (AFM) exhibits the excellent surface properties of spray-based TiO₂. The photoelectric conversion efficiency (PCE) is 14.31% when applied to planar perovskite solar cells based on metal electrodes. Finally, carbon nanotube (CNT) film electrode-based solar cells exhibits a 76% PCE compared with that of metal electrode-based solar cells, providing the possibility of commercialization.

• Journal of Periodontal and Implant Science
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• v.41 no.5
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• pp.227-233
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• 2011

Purpose: The aim of this study was to compare osteoblast behavior on zirconia and titanium under conditions cultured with bone morphogenetic protein-2. Methods: MC3T3-E1 cells were cultured on sandblasted zirconia and sandblasted/etched titanium discs. At 24 hours after seeding MC3T3-E1, the demineralized bone matrix (DBM) gel alone and the DBM gel with bone morphogenetic protein-2 (BMP-2) were added to the culture medium. The surface topography was examined by confocal laser scanning microscopy. Cellular proliferation was measured at 1, 4, and 7 days after gel loading. Alkaline phosphatase activity was measured at 7 days after gel loading. The mRNA expression of ALPase, bone sialoprotein, type I collagen, runt-related transcription factor 2 (Runx-2), osteocalcin, and osterix were evaluated by real-time polymerase chain reaction at 4 days and 7 days. Results: At 1, 4, and 7 days after loading the DBM gel alone and the DBM gel with BMP-2, cellular proliferation on the zirconia and titanium discs was similar and that of the groups cultured with the DBM gel alone and the DBM gel with BMP-2 was not significantly different, except for titanium with BMP-2 gel. ALPase activity was higher in the cells cultured with BMP-2 than in the other groups, but there was no difference between the zirconia and titanium. In ALPase, bone sialoprotein, osteocalcin, Runx-2 and osterix gene expression, that of cells on zirconia or titanium with BMP-2 gel was much more highly increased than titanium without gel at day 7. The gene expression level of cells cultured on zirconia with BMP-2 was higher than that on titanium with BMP-2 at day 7. Conclusions: The data in this study demonstrate that the osteoblastic cell attachment and proliferation of zirconia were comparable to those of titanium. With the stimulation of BMP-2, zirconia has a more pronounced effect on the proliferation and differentiation of the osteoblastic cells compared with titanium.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.445-449
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• 2020

Non-volatile memory is approaching its fundamental limits with the Si₃N₄ storage layer, necessitating the use of alternative materials to achieve a higher programming/erasing speed, larger storage window, and better data retention at lower operating voltage. This limitation has restricted the development of the charge-trap memory, but can be addressed by using high-k dielectrics. The paper reviews the doping of nitrogen, titanium, and yttrium on high-k dielectrics as a storage layer by comparing MONOS devices with different storage layers. The results show that nitrogen doping increases the storage window of the Gd₂O₃ storage layer and improves its charge retention. Titanium doping can increase the charge capture rate of HfO₂ storage layer. Yttrium doping increases the storage window of the BaTiO₃ storage layer and improves its fatigue characteristics. Parameters such as the dielectric constant, leakage current, and speed of the memory device can be controlled by maintaining a suitable amount of external impurities in the device.

• Journal of dental hygiene science
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• v.9 no.2
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• pp.153-160
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• 2009

The purposed of this study was to investigate the effect of Gold bonding agent as intermediate layer between metal substrate and ceramic coating. Gold bonding agent used to seal off any surface porosity, to mask the greyish color of the metal, and to provide an underlying bright golden hue to the ceramic coverage. The adhesion between metal substrate and ceramic is related to diffusion of oxygen during ceramic firing. The oxide layer produced on non-precious alloy anti titanium was considered to have a potentially adverse effect on metal-ceramic bonding. The oxidation characteristics of titanium and non-precious alloys are the main problem. Every group were divided into test and control groups. Control groups are carried out process of degassing for product oxide layer. Au coating was applied on each Ni-Cr, Co-Cr alloys and cp-Ti specimens with difference surface condition or degassing. Specimens surfaces and cutting plane was characterized by SEM/EDS. Results suggested that Au coating is effective barriers to protect metal oxidation during ceramic firing.