• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.375-380
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• 2016

The use of polyethylene film has a problem such as increasing rural environmental contamination, collection costs and farmers' workload. The objective of this study was to evaluate bio-degradable films in terms of yield of maize and soil environment. Treatments were bio-degradable film A (BDF A), bio-degradable film B (BDF B), high density polyethylene (HDPE), and non-mulched (NM) soil. Daily mean values of soil temperature (10 cm depth) under BDF A, BDF B, and HDPE were higher than in NM soil by 2.2, 2.8, $3.1^{\circ}C$ respectively. In the mulching cultivation of maize, bio-degradable film began to degrade from 50~60days after the planting. The degradation was much progressed in the harvest time and almost decomposed in the following spring. The weight of ear of maize was not shown significantly by mulching treatments. There were little changes of soil chemical properties for the bio-degradable film mulching. After using bio-degradable films, the contents of biomass-C and dehydrogenase activity increased from 92 to $137{\sim}147mg\;kg^{-1}$, and from 87 to $123{\sim}168mg\;kg^{-1}$ respectively.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.237-238
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• 2007

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.4
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• pp.145-150
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• 2007

The $SiO_2$ and $TiO_2$ thin films for the multilayer interference filter application were manufactured by electron beam process. In case of electron beam process with ion source, the anode current was controlled by gas volume ratio of $O_2$ and Ar. Substrate temperature of electron beam deposition without ion source was increased from 100 to $250^{\circ}C$ with $50^{\circ}C$ increment. The surface roughness values of $SiO_2$ thin films was most low value at $200^{\circ}C$ substrate temperature and 0.2 A anode current respectively. And the surface roughness values of $TiO_2$ thin films was most low value at room temperature and 0.2 A anode current repectively. The refractive index of $SiO_2$ and $TiO_2$ thin films to be deposited with ion source was usually lower than that of thin films without ion source.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.109-110
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• 2006

In bio applications, high temperature coefficient of resistance (TCR) at $30^{\circ}C{\sim}40^{\circ}C$ is especially important for a temperature sensor. In this work, single phase-vanadium dioxide ($VO_2$) thin films for temperature sensor were fabricated by reactive DC magnetron sputtering and post-annealing method. VOx thin films deposited by reactive sputtering in a controlled $Ar/O_2$ atmosphere can be transformed into single phase-$VO_2$ films by post-annealing in $N_2$ atmosphere. The grown $VO_2$ thin films have a moderate resistance at room temperature and very high TCR at room temperature and transition temperature, respectively 2.88%/K and 15.8%/K. A detailed structural characterization is performed by SEM, XRD and RBS. SEM morphology image indicates that grains of fabricated $VO_2$films are homogeneous and ball-like in shape. A fact that the films contain only single phase-$VO_2$ is obtained by XRD and RBS analysis. After deposition, the sensors were fabricated by micromachining technology. Silicon nitride membrane and black nickel were used for a thermal isolation structure and absorption layer. In the vicinity of room temperature, the TCR of sensors was enough high to apply for bio sensors.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1867-1870
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• 2013

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.378.2-378.2
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• 2016

Biosensors currently suffer from severe non-specific adsorption of proteins, which causes false positive errors in detection through overestimation of the affinity value. Overcoming this technical issue motivates our research. Polyethylene glycol (PEG) is well known for its ability to reduce the adsorption of biomolecules; hence, it is widely used in various areas of medicine and other biological fields. Likewise, amine functionalized surfaces are widely used for biochemical analysis, drug delivery, medical diagnostics and high throughput screening such as biochips. As a result, many coating techniques have been introduced, one of which is plasma polymerization - a powerful coating method due to its uniformity, homogeneity, mechanical and chemical stability, and excellent adhesion to any substrate. In our previous works, we successfully fabricated plasmapolymerized PEG (PP-PEG) films [1] and amine functionalized films [2] using the plasma enhanced chemical vapor deposition (PECVD) technique. In this research, an amine functionalized PP-PEG film was fabricated by using the plasma co-polymerization technique with PEG 200 and ethylenediamine (EDA) as co-precursors. A biocompatible amine functionalized film was surface characterized by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The density of the surface amine functional groups was carried out by quantitative analysis using UV-visible spectroscopy. We found through surface plasmon resonance (SPR) analysis that non-specific protein adsorption was drastically reduced on amine functionalized PP-PEG films. Our functionalized PP-PEG films show considerable potential for biotechnological applications such as biosensors.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.1
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• pp.34-41
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• 2002

CdS and $TiO_2$ nanoparticles were made by the precipitation method and sol-gel method, respectively, and they were mixed mechanically and then treated with the hydrothermal processing. CdS-$TiO_2$ composite particulate films were thus prepared by casting CdS-$TiO_2$ mixed sol onto $SnO_2$ conducting glass and a subsequent heat-treatment at $400^{\circ}C$. Again, the physico-chemical and photoelectrochemical properties of these films were controlled by the surface treatment with $TiCl_4$ aqueous solution. The photocurrents and the hydrogen production rates measured under the present experimental conditions varied in the range of $3.5{\sim}4.5mA/cm^2$ and $0.3{\sim}1.8cc/cm^2$-hr, respectively, and showed the maximum values at the $CdS/[CdS+TiO_2]$ mole ratio of 0.2. Also, the surface treatment with $TiCl_4$ aqueous solution caused a considerable improvement in the photocatalytic activity, Probably as a result of close contacts between the primary particles by the etching effect of $TiCl_4$ It was found that the photoelectrochemical performance of these particulate films could be effectively enhanced by this approach.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.789-790
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• 2005

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.231-231
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• 2012

Correct determination of the interface locations is critical for the calibration of the depth scale and measurement of layer thickness in SIMS depth profiling analysis of multilayer films. However, the interface locations are difficult to determine due to the unwanted distortion from the real ones by the several effects due to sputtering with energetic ions. In this study, the layer thicknesses of Si/Ge and Si/Ti multilayer films were measured by SIMS depth profiling analysis using the oxygen and cesium primary ion beam. The interface locations in the multilayer films could be determined by two methods. The interfaces can be determined by the 50 at% definition where the atomic fractions of the constituent layer elements drop or rise to 50 at% at the interfaces. In this method, the raw depth profiles were converted to compositional depth profiles through the two-step conversion process using the alloy reference relative sensitivity factors (AR-RSF) determined by the alloy reference films with well-known compositions determined by Rutherford backscattering spectroscopy (RBS). The interface locations of the Si/Ge and Si/Ti multilayer films were also determined from the intensities of the interfacial composited ions (SiGe+, SiTi+). The determination of the interface locations from the composited ions was found to be difficult to apply due to the small intensity and the unclear variation at the interfaces.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.71-78
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• 1996

This experiments were conducted using color films for investigation of suitable light environment on the growth of Allium senescens var. minor. The results obtained were as follows ; In characteristics of light transmittance of the color films tested, it shows that glass and transparent film passed nearly all visible rays, but the other films were reduced and filtered certain wavelength of light. On the tested films, the light transmittance amount of transparent film and green film were the greatest, 75.5% and smallest, 13.2% based on the glass 100%, respectively. The growth of Allium senescens var. minor increased at transparent, yellow and pink film, but decreased at blue and green film. It shows that the greatest chlorophyll content was founded in the blue film, 0.27mg/g, the smallest founded in the yellow film, 0.16mg/g. The content of mineral elements was founded that the green film was the highest at N, P, K, Ca, Mg, but the orange and pink film were the lowest at P, K and N, Ca, Mg, respectively.