We have performed density functional theory calculations to understand the initial growth of graphene by studying the adsorption of carbon atoms on the oxide substrates such as magnesium oxide. For adsorption behaviors of carbon atoms on the MgO(100) surface, their adsorption geometries and binding energies are calculated. The binding of a carbon atom is the most stable at the on-top oxygen site on MgO(100). Such strong C–O binding is analyzed by examining the projected density of states. Then, we also increase the number of carbon atoms on MgO(100) to investigate their adsorption behaviors. Due to strong binding between carbon atoms, adsorbed carbon atoms form chain-like or graphene-like structures on the surface. Combined with relatively strong C–O binding, this result may explain the graphene growth on MgO(100) observed in available experiments.

ZnO–SnO₂ branch–stem nanostructures were realized on a basis of a two-step process. In step 1, SnO₂-stem nanowires were synthesized. In step 2, ZnO-branch nanowires were successfully grown on the SnO₂-stem nanowires through a simple evaporation technique. We have pre-deposited thin Au layers on the surface of SnO₂ nanowire stems and subsequently evaporated Zn powders on the nanowires. The ZnO branches, which sprouted from the SnO₂ stems, had diameters in a range of 30–35 nm. As-synthesized branches were of single crystalline hexagonal ZnO structures. Since the branch tips were comprised of Au-containing nanoparticles, the Au-catalyzed vapor–liquid–solid growth mechanism was more likely to control the growth process of the ZnO branches. To test a potential use of ZnO–SnO₂ branch–stem nanostructures in chemical gas sensors, their sensing performances with respect to NO₂ gas were investigated, showing the promising potential in chemical gas sensors.

The recent studies carried out on the binding of small molecule to deoxyribonucleic acids suggested that the intercalation of a tricyclic heteroaromatic molecule, thionine, with natural DNAs provided thermal stabilization to the DNA complex. In the present study, we reported theoretical analysis of thionine binding with natural DNAs of varying base composition by using an amended Zimm and Bragg theory, to explain the melting behaviour and heat capacity of DNAs with and without thionine binding. We used experimental models of Paul et al. for implementing this study (Paul et al., 2010). The sharpness of transition has been examined in terms of half width and sensitivity parameter (ΔH/σ). The results of theoretical analysis concluded that the various parameters such as heat capacity curve, transition profile, half widths and sharpness of the transition are in good agreement with the experimental measurements for binding of thionine determined through DSC. The theoretical analysis proposed in this study, therefore, may be useful to understand interaction of small molecules with deoxyribonucleic acids. This approach may also be applied to design DNA binding therapeutic molecules and in the process of drug formulation and development.

Polydimethylsiloxane (PDMS) thin films were deposited on Ni particles with a mean size of ∼1 μm using chemical vapor deposition method. The thin films consisting of these PDMS-covered Ni particles showed a water contact angle higher than 160°, corresponding to the superhydrophobicity. These superhydrophobic films were found to be resistant toward acidic and basic media. The PDMS-covered Ni particles showed high affinity toward non-polar organic solvent such as toluene. Together with an external magnetic field, the PDMS-covered Ni can be used for separating water and toluene from a water/toluene heterogeneous mixture.

Real time feedback control of plasma density was developed and carried out in an inductively coupled plasma. This control method uses a floating probe as a sensor because it can measure plasma density in real time without modification of the plasma reactors and it does not perturb the plasma. The results show that through feedback control, plasma density can be maintained constant within a steady state error of less than 0.3% even if there is a sudden pressure disturbance. This feedback control method is expected to improve the repeatability and reliability of plasma reactors.

Graphene-containing carbon aerogel was prepared by a sol–gel polymerization of resorcinol-formaldehyde (RF) method using polyethyleneimine (PEI)-modified chemically exfoliated grapheme oxide, and its electrochemical performance as an electrode for supercapacitor was examined. The effect of PEI in the preparation of RFGO (resorcinol-formaldehyde and graphene oxide) solution on the physicochemical and electrochemical properties of graphene-containing carbon aerogel (CAPG) was investigated. For comparison, graphene-containing carbon aerogel was prepared using PEI-free graphene oxide (CAG). Graphene-free carbon aerogel (CA) was also prepared. CAPG showed the highest BET surface area (792 m²/g) and the largest pore volume (1.64 cm³/g) with well-developed porous structure. Various electrochemical measurements revealed that CAPG showed high specific capacitance (205 F/g), low equivalent series resistance (0.55 Ω), and superior capacitive behavior. The PEI-modified graphene oxide played an important role in enhancing physicochemical properties and supercapacitive electrochemical performance of CAPG.

In this study, we present numerical and experimental analyses of the effect of the work function of the transparent conducting oxide (TCO) on the performance of silicon heterojunction solar cells. The simulation results showed that the solar cell performance such as Vₒc and FF were strongly affected by the work function of TCO films due to band bending. The experimental analysis was carried out by preparing Zn–In–Sn–O films with varying work function by varying the composition. The compositional dependence of the work function, optical and electronic properties of Zn–In–Sn–O films was examined, and the performance of the silicon heterojunction solar cells with corresponding TCO films was analyzed. The electrical properties and work function in Zn–In–Sn–O films were significantly influenced by Zn content, and Zn–In–Sn–O film with 12.7 at.% Zn content, which had the highest work function and lowest resistivity among the studied films, resulted in the highest conversion efficiency of solar cell due to increased Vₒc and FF. It was shown that the behavior of performance parameters in silicone heterojunction solar cells closely correlated with the work function and electrical properties of TCO films.

Phosphate glasses doped with Mn⁴⁺ ion were prepared using high temperature melting method. Under 408 nm excitation, the peak wavelength and lifetime of the fluorescence are related to the Mn⁴⁺ ion concentration. With the increasing of Mn⁴⁺ ion concentration, the fluorescence wavelength varies from 605 nm to 685 nm and the lifetime increases from several microseconds to one millisecond. The fluorescence wavelength is variable and the lifetime is tunable for our materials.

This study aimed to evaluate the use of a dielectric barrier discharge (DBD) plasma system to improve the safety of pork loins. When pork loin was exposed to DBD plasma with the input gases He and He + O₂, the population of Escherichia coli was reduced by 0.26 and 0.50 log cycles following a 5-min treatment and by 0.34 and 0.55 log units following a 10-min treatment, respectively. That of Listeria monocytogenes was also reduced from 0.17 to 0.35 and 0.43 to 0.59 log cycles when the samples were exposed to DBD for 5 and 10 min using He and He + O₂, respectively. The pH and L*-values (lightness) of the samples decreased significantly with DBD plasma treatment, but a*- (redness) and b*-values (yellowness) exhibited no obvious changes. Lipid oxidation, measured by TBARS values, was greater in samples with He + O₂ than in other samples. Significant reductions in sensory quality parameters (appearance, color, odor, acceptability, etc.) were observed in DBD-treated samples. These results indicate that the DBD plasma system has potential for use in sanitizing pork loins by inactivation of foodborne pathogens, although the effect was limited. In order to meet market requirements, however, a method to overcome sensory deterioration of pork loins should be developed and applied.