• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.15-23
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• 2004

Deicer operations provide traffic safety during winter driving conditions in urban areas. Using large quantities of de-icing chemicals (i.e., $CaCl_2$ and NaCl) can cause serious environmental problems and may change behaviors of heavy metals in roadside sediments, resulting in an increase in mobilization of heavy metals due to complexation of heavy metals with chloride ions. To examine effect of de-icing salt concentration on the leaching behaviors and mobility of heavy metals (cadmium, zinc, copper, lead, arsenic, nickel, chromium, cobalt, manganese, and iron), leaching experiments were conducted on roadside sediments collected from Seoul city using de-icing salt solutions having various concentrations (0.01-5.0M). Results indicate that zinc, copper, and manganese in roadside sediments were easily mobilized, whereas chromium and cobalt remain strongly fixed. The zinc, copper and manganese concentrations measured in the leaching experiments were relatively high. De-icing salts can cause a decrease in partitioning between adsorbed (or precipitated) and dissolved metals, resulting in an increase in concentrations of dissolved metals in salt laden snowmelt. As a result, run-off water quality can be degraded. The de-icing salt applied on the road surface also lead to infiltration and contamination of heavy metal to groundwater.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.3
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• pp.152-157
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• 1999

Oil leaked from underwound storage tanks and leachate from sanitary landfills have been known as contaminant sources of the high-quality groundwater resources. The mobility of contaminants in the aquifer largely depends on the groundwater flow and the determination of associated hydraulic parameters is essential for a proper remediation of contaminated grnundwater. This study aimed at determining an optimum set of hydraulic parameters for an unconfined sandy aquifer of a laboratory scale through comparison of various methods. Results showed that the specific yield obtained from gravity drainage experiment was an average of 0.20 with minor variations in aquifer depths. and the permeabilities obtained from Dupuit approximation and slug test gave similar values of 5.33 cm/min and 5.85 cm/min but the constant head method gave 0.17 cm/min, which is much ion than the other methods. This experimental evidence reveals that the permeability of the unconfined sandy aquifer could be accurately determined by Dupuit assumption or slug tut rather than by constant head method conducted for a disturbed separate soil column.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.407-413
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• 1998

The influence of the anion composition of simulated acid rain on cation leaching of two soils with different surface charge properties was examined. Four mixtures of mole ratio of $SO_4:NO_3$(1:0, 2:1, 1:1, 0:1) with pH 2.0 simulated acid rain were applied to an Inceptisols(Gyuam series) and Andisols(Pyeongdae series). The Andisols had higher $SO_4{^{2-}}$ adsorption capacity than the Inceptisols because of its higher point of zero charge(PZC, pH 6.5) than Inceptisols(PZC pH 3.1). Cation leaching in Andisols varied directly with the $NO_3$ content of the leaching input due to higher mobility of $NO_3$ compared with $SO_4$ that was absorbed. The pH of the Andisols was higher with the addition of $Na_2SO_4$ than the addition of $NaNO_3$ indicating that this soil behaves as a base and has a high $SO_4$ adsorption capacity. The relative $NO_3{^-}/SO_4{^{2-}}$ content input had no effect on cation leaching of the Inceptisols. Amounts of leaching on the Andisols by simulated acid rain were higher than Inceptisols. This experiment explained that anion composition of acid rain plays a significant role in the cation leaching of soils which are able to adsorb $SO_4$.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.59-59
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• 2010

Graphene is a 2-D sheet of $sp^2$-bonded carbon arranged in a honeycomb lattice. This material has attracted major interest, and there are many ongoing efforts in developing graphene devices because of its high charge mobility and crystal quality. Therefore clear understanding of the substrate effect and mechanism of synthesis of graphene is important for potential applications and device fabrication of graphene. In a published paper in J. Phys. Chem. C (2008), the effect of substrate on the atomic/electronic structures of graphene is negligible for graphene made by mechanical cleavage. However, nobody shows the interaction between Ni substrate and graphene. Therefore, we have studied this interaction. In order to studying these effect between graphene and Ni substrate, We have observed graphene synthesized on Ni substrate and graphene transferred on $SiO_2$/Si substrate through Raman spectroscopy. Because Raman spectroscopy has historically been used to probe structural and electronic characteristics of graphite materials, providing useful information on the defects (D-band), in-plane vibration of sp2 carbon atoms (G-band), as well as the stacking orders (2D-band), we selected this as analysis tool. In our study, we could not observe the doping effect between graphene and Ni substrate or between graphene and $SiO_2$/Si substrate because the shift of G band in Raman spectrum was not occurred by charge transfer. We could noticed that the bonding force between graphene and Ni substrate is more strong than Van de Waals force which is the interaction between graphene and $SiO_2$/Si. Furthermore, the synthesized graphene on Ni substrate was in compressive strain. This phenomenon was observed by 2D band blue-shift in Raman spectrum. And, we consider that the graphene is incommensurate growth with Ni polycrystalline substrate.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.7-8
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• 2010

The surface conductive layer (SCL) of chemical vapor deposition (CVD) diamonds has attracting much interest. However, neither photoemission electron microscopic (PEEM) nor micro-spectroscopic (PEEMS) information is available so far. Since SCL retains in an ultra-high vacuum (UHV) condition, PEEM or PEEMS study will give an insight of SCL, which is the subject of the present study. The sample was made on a Ib-type HTHP diamond (001) substrate by non-doping CVD growthin a DC-plasma deposition chamber. The SCL properties of the sample in air were; a few tens K/Sq. in sheet resistance, ${\sim}180\;cm^2/vs$ in Hall mobility, ${\sim}2{\times}10^{12}/cm^2$ in carrier concentration. The root-square-mean surface roughness (Rq) of the sample was ~0.2nm as checked by AFM. A $2{\times}1$ LEED pattern and a sheet resistance of several hundreds K/Sq. in UHV were checked in a UHV chamber with an in-situ resist-meter [1]. The sample was then installed in a commercial PEEM/S apparatus (Omicron FOCUS IS-PEEM) which was composed of electro-static-lens optics together with an electron energy-analyzer. The presence of SCL was regularly monitored by measuring resistance between two electrodes (colloidal graphite) pasted on the two ends of sample surface. Figure 1 shows two PEEM images of a same area of the sample; a) is excited with a Hg-lamp and b) with a Xe-lamp. The maximum photon energy of the Hg-lamp is ~4.9 eV which is smaller that the band gap energy ($E_G=5.5\;eV$) of diamond and the maximum photon energy of the Xe-lamp is ~6.2 eV which is larger than $E_G$. The image that appear with the Hg-lamp can be due to photo-excitation to unoccupied states of the hydrogen-terminated negative electron affinity (NEA) diamond surface [2]. Secondary electron energy distribution of the white background of Figs.1a) and b) indeed shows that the whole surface is NEA except a large black dot on the upper center. However, Figs.1a) and 1b) show several features that are qualitatively different from each other. Some of the differences are the followings: the two main dark lines A and B in Fig.1b) are not at all obvious and the white lines B and C in Fig.1b) appear to be dark lines in Fig.1a). A PEEMS analysis of secondary electron energy distribution showed that all of the features A-D have negative electron affinity with marginal differences among them. These differences can be attributed to differences in the details of energy band bending underneath the surface present in SCL [3].

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.131-131
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• 2013

A single-layer graphene has been uniformly grown on a Cu surface at elevated temperatures by thermally processing a poly(methyl methacrylate) (PMMA) film in a rapid thermal annealing (RTA) system under vacuum. The detailed chemistry of the transition from solid-state carbon to graphene on the catalytic Cu surface was investigated by performing in-situ residual gas analysis while PMMA/Cu-foil samples being heated, in conjunction with interrupted growth studies to reconstruct ex-situ the heating process. The data clearly show that the formation of graphene occurs with hydrocarbon molecules vaporized from PMMA, such as methane and/or methyl radicals, as precursors rather than by the direct graphitization of solid-state carbon. We also found that the temperature for vaporizing hydrocarbon molecules from PMMA and the length of time the gaseous hydrocarbon atmosphere is maintained, which are dependent on both the heating temperature profile and the amount of a solid carbon feedstock are the dominant factors to determine the crystalline quality of the resulting graphene film. Under optimal growth conditions, the PMMA-derived graphene was found to have a carrier (hole) mobility as high as ~2,700 cm2V-1s-1 at room temperature, superior to common graphene converted from solid carbon.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.89-97
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• 1999

Through manifestation of the principles of commodity production spatial sharing of labour can be observed in the agriculture as well as in cattle production. Better adjustment of the production structure to the environment factors brings higher yields and more effective production. In being able to maximize the profit the entrepreneurs opt for producing output that closely matches to their featuring conditions. In contrary to the relatively high "mobility" of crop production animal husbandry and within this cattle production - as known - is strictly chained to forage production. On the basis of our economic research and as a result of multivariable analysis(factor analysis) it can be concluded that two variable groups(factors) are highly dominant in organizing profitable cattle production. First of them is the crop site factor (indicated by gold crown value), the second is the forage production feature(forage and grassland area and the yield of them). During recent years the weight of environmental factors suffered from devaluation. As a result of the central economic administration differentiating effects were suppressed and the chances of equalizing concepts strengthened. The outcome can be observed even today. In the regions, for example, being predominantly suitable for grass and forage cropping the milk and slaughter cattle production decreased. The same is ture for com and pig production regions. Unexploitment of local environmental features can be observed mainly in grassland management. Branches being potential user of grasslands hardly take them into consideration. Main method of rational use of grasslands is pasturing. Presence of pastures and the usage of them through cattle production is highly important not only for profitable production but also for maintaining ecological stability.

• Bulletin of the Korean Chemical Society
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• v.7 no.2
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• pp.137-142
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• 1986

The luminescence spectra of $Ru(bpy)_3^{2+}$ in poly(methacrylic acid) (PMA) solutions varied sensitively with pH. At pH < 5.5, the emission intensity increased with pH up to 4 times, while it decreased with pH beyond the pH. The enhanced emission intensity was accompanied by blue-shift of the emission maxima as much as 15 nm. The enhancement of emission intensity was attributed to the restricted rotational mobility of ligand of the cation bound to densely coiled PMA molecules at pH < 5.5. The sharp decrease in emission intensity with increasing pH near pH 5.6 was accounted for conformational transition of the polymer to more extended structure, which was also revealed in viscosity measurement. The enhancement of emission intensity became higher as NaCl concentration of the solution increased. The binding constant of $Ru(bpy)_3^{2+}$ with two carboxylate groups of PMA was calculated as $2{\times}10^5\;M^{-1}$ in 0.1 M NaCl at pH 5.2. The pH dependence of luminescence quenching rate of $Ru(bpy)_3^{2+}$ by $Cu^{++}$ also showed maximum near pH 5, and the rate was more than $10^3$ times higher than that in water, whereas the maximum enhancement of quenching rate (about 20 times) in poly(acrylic acid) (PAA) solution occurred at pH 4.5. On the other hand, the pH dependence for neutral water soluble nitrobenzene (NB) exhibited opposite trend to that of $Cu^{++}$. The quenching constant vs pH curve for $MV^{++}$ was composite of those for $Cu^{++}$ and NB. The anomalous high quenching rate for $Cu^{++}$ in PMA solution at pH < 5.5 was attributed to the binding of $Ru(bpy)_3^{2+}$ and $Cu^{++}$ to the same region of PMA, when it conforms densely coiled structure in the pH range. The observation of mininium quenching rate for NB near pH 5.5 indicated that the $Ru(bpy)_3^{2+}$ bound to the densely coiled PMA is not accessible by NB, which is in bulk water phase. The composite nature of the pH dependence of quenching rate for $MV^{++}$ in PMA solution was attributed to the smaller binding affinity of the cation to PMA, compared to that of $Cu^{++}$. The sharp, cooperative conformational transition with pH observed in PMA was not revealed in PAA. But, the pH dependence of quenching rates in this polymer reflected increased charge density and, thus, binding of cations to the polymer, and expansion of the polymer chain with pH.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.15-23
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• 1986

This study has been carried out to acquire some basic informations on the digestive fluid of Silkworm, Bombyx mori for developing artficial diets. Silkworms reared on mulberry leaves and artificial diet, were used in this experiments. The results obtained are as follows ; 1. The Red Fluorescent protein was precipitated in 50% acetone solution and did not dissolved in n-butanol solution, but dissolved in methanol solution. 2. Electrophoretic analysis results of mulberry leaves rearing B. mori and artificial diet rearing B. mori, which has been treated with 50% acetone solution were as follows. i) There was distinct difference at the position of high mobility ii) Red Fluorescence was observed only at the position of first band of mulberry leaves rearing B. mori. iii) No different was shown in the electrophoretic patterns of mulberry leaves rearing B. mori on 5th instar 1st-3rd day, but some difference on 5th instar 4th, 5th day. 3. The RFP is the basic protein which has PI 8-9 according to the isoelectric electrophhoresis. 4. The SDS-polyacrylamide gel electrophoresis analysis showed that the molecular weight of RFP was 27,000. 5. The Sephadex G-75 chromatographic analysis showed that there was three peaks between number 16 and 28 in the mulberry leaves rearing B. mori chromatogram, but two peaks between number 18 and 31 in the artifical diet rearing B. mori chromatogram.

• Cross-Cultural Studies
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• v.53
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• pp.193-218
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• 2018

In this essay, I examine the interactions of chronotopes in the narrative of Gangnam Blues, a film written and directed by Yu Ha and released in 2015. Bakhtin's chronotope, the connectedness of temporal and spatial relationships in literary narratives, provides the background for the representability of events and becomes the organizing center for the events. Each chronotope offers a different way of acting, interacting and understanding experience, and chronotopes can interact with each other in a single text or between the reader and the represented world. Gangnam Blues is a gangster movie, first of all, showing an individual's illusion of an unlimited possibility for achieving wealth and power. At the same time, the film describes the government's project to transform Gangam, a rural area in the south of the Han, into a new downtown and residential area for Seoul. As the world in the narrative and the world of the author or the reader are all chronotopic, we can see the interactions of chronotopes between the narrative of an individual and the historical narrative, as well as between the narrative about the beginning of Gangnam and the audience's perception of the present Gangnam. In this film, the main character's ambition is shown as part of the social desire for rapid economic achievements in the 1970s, along with high social mobility. The social desire can be explained as envy, as it is fueled by social comparisons and competitions. The main character's pursuit of money and power through the possession of Gangnam land overlaps with the envious desire for the present Gangnam shared by many. The individual's exceptional ambition and violence are not fully examined in this text. Moreover, the film's dependence on the feelings of envy to represent the individual's choice and violence can be a symptom of the lack of critical distance from social desire and envy.