• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.77.2-77.2
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• 2019

NGC 4522 is one of the best-known examples among the Virgo galaxies undergoing active ram pressure stripping. There have been a number of detailed observational and theoretical studies on this galaxy to constrain its stripping and star formation history. However, the impact of ram pressure on the multi-phased ISM, in particular molecular gas which plays an important role in star formation, is still not fully understood. NGC 4522, as a system where the extra-planar molecular gas is identified, is an ideal case to probe in depth how ram pressure affects molecular gas properties. Aiming to get more theoretical insights on the detailed stripping process of multi-phased ISM and its consequences, we have conducted simulations using the TIGRESS which could reproduce the realistic ISM under comparable conditions as NGC 4522. In this work, we compare the fraction of gas mass to stellar mass, star formation rates and gas depletion time scales of NGC 4522 with those measured from the simulations, not only inside the disk but also in the extra-planar space.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.933-937
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• 2012

In the present study, we evaluate the sensitivity and optimal stripping voltammetry (SV) conditions of copper (Cu), which is one of the main trace heavy metals inducing the environmental contamination, using carbon nanotube (CNT) electrode. In addition, the reaction mechanism of stripping reaction of Cu is investigated. The electrochemical analyses such as squarewave stripping voltammetry (SWSV) and linear scan voltammetry (LSV) are used for the evaluations. As a result of that, the best SWSV conditions like squarewave amplitude of 15 mV, frequency of 60 Hz, deposition potential of -1.0V vs. Ag/AgCl and deposition time of 200s are determined with the measured Cu sensitivity of $1.824{\mu}A/{\mu}M$. As a driving force affecting the stripping reaction of Cu, surface reaction is more dominant one than diffusion. These results are compared with other reference results and it is confirmed that our suggested CNT electrode gives rise to better Cu sensitivity result than other references.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.9
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• pp.513-520
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• 2016

It is well known that volatile compounds including disinfection by-products as well as emissive dissolved gas in water can be removed effectively by air stripping. The micro-bubbles of flotation unit are so tiny as microns while the diameter of fine bubbles applied to air stripping is ranged from hundreds to thousands of micrometer. Therefore, the micro-bubbles in flotation can supply very wide specific surface area to transfer volatile matters through gas-liquid boundary. In addition, long emission time also can be gained to emit the volatile compound owing to the slow rise velocity of micro-bubbles in the flotation tank. There was a significant difference of the THMs species removal efficiency between air stripping and flotation experiments in this study. Moreover, the results of comparative experiments on the removal characteristics of THMs between air stripping and flotation revealed that the mass transfer coefficient, $K_La$ showed obvious differences. To overcome the limit of low removal efficiency of dissolved volatile compounds such as THMs in flotation process, the operation range of bubble volume concentration is required to higher than the operation condition of conventional particle separation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.99-104
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• 2007

The skin barrier function is one of the vital functions. Horny layer and epidermis among various skin layers play an important role in protecting body from environmental insults. Stratum corneum is completely formed by differentiation processes from the basal layer and newly formed corneocytes push the older ones from skin surface. In this study we investigated changes of various parameters - capacitance, transepidermal water loss (TEWL), pH and amount of removed corneocytes - according to the stratum corneum's depth. We removed the stratum corneum using tape stripping technique. We found that uppermost stratum corneum play an important role in skin surface moisturization and lower stratum corneum in protecting transepidermal water loss. In addition, skin pH is more acidic than surface pH. In the stratum corneum, skin pH is mote acidic in the deeper layer. Furthermore amount of removed corneocyte is also decreased according to depth because of stronger cell-cell union strength. From these results we suggest that stratum corneum has different characteristics depending on their position.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3501-3504
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• 2011

• Electrical & Electronic Materials
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• v.9 no.9
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• pp.918-924
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• 1996

A downstream oxygen plasma is generated by capacitively coupled RF power and applied to photoresist stripping. Stripping rate (ashing rate) is measured in terms of RF power, chamber pressure, oxygen flow rate and temperature. Ashing reaction is thermally activated and depends on oxygen radical density. The ashing process is optimized to have the high ashing rate, good uniformity and minimal plasma damage using a statistical method.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.61.2-61.2
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• 2011

HI gas disks are known to be the largest ISM reservoir in most late type galaxies. When the HI properties of galaxies such as total mass, density, and distribution change, the galaxies may evolve quite differently. In this talk, I will present two groups of galaxies, one undergoing HI stripping and one accreting more gas. I will discuss causes of gas stripping and accretion, and possible consequences in galaxy evolution.

• Journal of Korean Society on Water Environment
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• v.20 no.1
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• pp.86-92
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• 2004

Lab-scale experiments have been carried out to investigate ammonia stripping with a modified spray tower for removing ammonia nitrogen from swine wastewater. The operating conditions such as initial pH, temperature, air flow, hole size of distributor determining the diameter of water drops, and influent solids concentration were closely examined focusing on removal efficiency of ammonia. As a result of the experiment, in order to achieve high rate of ammonia removal by the air stripping system, the air flow rate must be supplied at high rate with sufficiently high initial pH, temperature. The optimum operating condition to meet the residual ammonia concentration of 300 mg/L was the initial pH of 11.0 at $35^{\circ}C$ with the air flow rate of 20 L/min. It also showed that the smaller hole size is, the higher removal rate of ammonia is expected. However, when used a small sized distributor (2 mm), the flooding problem at the upper column occurred due to clogging of the hole. With regard to the influent solids concentration, it was showed that the lower concentration of solids, the higher removal rate of ammonia. The removal of particulate materials in influent led to improve the removal efficiency of ammonia, rather than to control the operating condition including initial pH, temperature, and air flow. The empirical correlation between KLa and operating parameters would be driven as, $K_{La}=(0.0003T-0.0047){\cdot}G^{0.3926}{\cdot}L^{-0.5169}{\cdot}C^{-0. 1849}$. The calculated $K_{La}$ from proposed formula can be used effectively to estimate the optimum reaction time and to calculate the volume of modified spray tower system.

• International Journal of Highway Engineering
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• v.3 no.4 s.10
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• pp.105-116
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• 2001

This study was performed to evaluate the characteristics of waste foundry sand (WFS) and the asphalt mixture made of a foundry waste sand. To estimate the applicability of WFS, chemical and physical properties were measured by XRF(X-ray fluorescent), and SEM(Scanning electronic microfilm). To improve the stripping resistance of WFS asphalt mixture, anti-stripping agents (a hydrated lime and a liquid anti-stripping agent) were used. To improve tensile properties and durability of WFS asphalt concrete mixture, LDPE(low-density polyethylene) was used as an asphalt modifier Marshall mix design, indirect tensile strength, tensile strength ratio(TSR) after freezing and thawing, moisture susceptibility and wheel tracking tests were carried out to evaluate performance of WFS asphalt concrete. Comparing with conventional asphalt concrete, WFS asphalt concretes showed similar or the better qualify in mechanical properties, and satisfied all specification limits. Therefore, it Is concluded that waste foundry sand can be recycled as an asphalt pavement material.

• Toxicological Research
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• v.24 no.3
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• pp.227-233
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• 2008

To detect lead ions using electrochemical voltammetric analysis, Infrared Photo-Diode Electrode(IPDE) was applied via cyclic and square wave stripping voltammetry. Lead ions were deposited at 0.5 V(versus Ag/AgCl) accumulation potential. Instrumental measurements systems were made based on a simple and compact detection system. The stripping voltammetric and cyclic voltammetric optimal parameters were searched. The results yielded a cyclic range of $40{\sim}240mgl^{-1}$ Pb(II) and a square wave stripping working range of $0.5{\sim}5.00mgl^{-1}$ Pb(II). The relative standard deviation at 2 and 4 $mgl^{-1}$ Pb(II) was 0.04% and 0.02%(n=15), respectively, using the stripping voltammetric conditions. The detection limit was found to be 0.05 $mgl^{-1}$ with a 40 sec preconcentration time. Analytical interference ions were also evaluated. The proposed method was applied to determine lead ions in various samples.