• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.272-278
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• 2016

Porous pavements are recommended as a Low-Impact Development (LID) method which is a strategy to develop a water cycle as close to a natural state as possible, and to solve the urban impervious surface problems. Porous pavements can yield a solution if it provides a more permeable surface with extra space to contain extra water from building roofs. But there are few applications in Korea because of a lack of recognition and experience. Highway engineers are mainly concerned about the infiltration of water into pavement structures. They worry about the weakening of the asphalt mixture and subgrade, and freezing during the winter season due to the infiltration of water. Meanwhile, hydrological experts doubt the effects of the amount of water to control during the flooding season, and environmental experts prefer a non-point pollution treatment system established beside highway. In this study, from reviewing the history and the body of literature about porous pavements, conclusions regarding the most advanced technologies were made. First, traditional thickness designs can be used for porous pavement, no extra distresses was found by weakening and freezing during the winter season. Second, hydrological design can be made by controlling the thickness of the pavement and the outlet of water. Third, the treatment efficiency of non-point pollution of porous pavements is not worse than any other method. Importantly, it's a more eco-friendly solution because of its lower requirement for de-icing agents.

• Journal of Embryo Transfer
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• v.28 no.1
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• pp.7-12
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• 2013

Body condition score (BCS) is a useful management tool for distinguishing differences in nutritional needs of cows in the herd. Although it is not always possible to quantify the nutrient content of the feed supplied to the donor cow, the nutritional status can be determined by the BCS. The objective of this study was to evaluate in vivo embryo production, return to estrous of donor and pregnancy rate of recipients following BCS in Hanwoo superovulation. Sixty nine Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with Embryo Collection Medium. The results obtained were as follows: No differences were observed in the efficiency of superovulation rates regardless of BCS ($${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$). The mean number of total embryos was each $5.20{\pm}0.86$, $11.56{\pm}1.04$, and $6.23{\pm}1.07$. The mean number of transferable embryo from $${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$ of BCS was $2.60{\pm}0.87$, $7.94{\pm}0.89$, and $4.75{\pm}1.32$, respectively (p<0.05). Return to estrous regardless of donor BCS was no difference. The pregnancy rates of recipient were BCS $${\leq_-}2.0$$ 11.76%, 2.5 to 3.0 40.79%, and $${\geq_-}3.5$$ 11.11%, following transfer of fresh embryos produced in vivo, respectively. These results indicate that if the Hanwoo with BCS 2.5 to 3.3 are used for donor and recipient, the embryo production and the conception rate will be greater.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.1 no.1
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• pp.65-72
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• 2003

Adsorption and desorption characteristics of methyl iodide at high temperature conditions up to 25$0^{\circ}C$ by TEDA-impregnated activated carbon and silver-ion exchanged zeolite(AgX-10), which are used for radioiodine retention in nuclear facility, were experimentally evaluated. In the range of temperature from 3$0^{\circ}C$ to 25$0^{\circ}C$, the adsorption capacity of base activated carbon decreased sharply with increasing temperature but that of TEDA-impregnated activated carbon showed higher value even at high temperature ranges. Especially, the residual amount of methyl iodide after desorption on TEDA-AC represented 30% lower value than that on AgX-10. However, it can be used as an adsorbent for the removal of methyl iodide up to 15$0^{\circ}C$ if it is preventing explosion by Ignition. The breakthrough curves of methyl iodide in the fixed bed packed with AgX-10 uP to 40$0^{\circ}C$ were compared upon the effects of bed temperatures, bed depth and input concentration of methyl iodide. Removal mechanism of methyl iodide on AgX-10 was proposed, based on the analysis of by-product gas generated from adsorption reaction.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.49-61
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• 2006

This study suggests long-life asphalt pavement method which can save maintenance cost by increasing the design and performance period of pavements. The high modulus asphalt binder developed and then various physical tests are performed. Laboratory performance tests and accelerated pavement test are conducted for the high modulus and conventional mixtures. The test results show that dynamic modulus values of high modulus mixtures are higher than those of the conventional mixtures, The high modulus mixtures yield better fatigue, rutting and moisture damage performance than conventional mixtures. Structural analysis is performed and a database is built up for long life asphalt pavement design. Pavement response model is developed through a multiple regression analysis program, SPSS using the database. A design software for the long life pavements is developed based on the pavement response model and laboratory and field performance tests results. In addition, optimum pavement sections and materials are suggested. The suggested AC thickness of long life asphalt pavement is 29cm. A Life cycle cost analysis(LCCA) is conducted to check the economical efficiency of the long life pavement section. The LCCA result shows that initial construction costs of long life and conventional pavements are almost equal, but long life pavement is more profitable in terms of the LCCA.

• Proceedings of the Korean Society of Toxicology Conference
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• 2006.11a
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• pp.65-74
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• 2006

Modem drug discovery requires rapid pharmacokinetic evaluation of chemically diverse compounds for early candidate selection. This demands the development of analytical methods that offer high-throughput of samples. Naturally, liquid chromatography / tandem mass spectrometry (LC-MS/MS) is choice of the analytical method because of its superior sensitivity and selectivity. As a result of the short analysis time(typically 3-5min) by LC-MS/MS, sample preparation has become the rate- determining step in the whole analytical cycle. Consequently tremendous efforts are being made to speed up and automate this step. In a typical automated 96-well SPE(solid-phase extraction) procedure, plasma samples are transferred to the 96-well SPE plate, internal standard and aqueous buffer solutions are added and then vacuum is applied using the robotic liquid handling system. It takes only 20-90 min to process 96 samples by automated SPE and the analyst is physically occupied for only approximately 10 min. Recently, the ultra-high flow rate liquid chromatography (turbulent-flow chromatography)has sparked a huge interest for rapid and direct quantitation of drugs in plasma. There is no sample preparation except for sample aliquotting, internal standard addition and centrifugation. This type of analysis is achieved by using a small diameter column with a large particle size(30-5O ${\mu}$m) and a high flow rate, typically between 3-5 ml/min. Silica-based monolithic HPLC columns contain a novel chromatographic support in which the traditional particulate packing has been replaced with a single, continuous network (monolith) of pcrous silica. The main advantage of such a network is decreased backpressure due to macropores (2 ${\mu}$m) throughout the network. This allows high flow rates, and hence fast analyses that are unattainable with traditional particulate columns. The reduction of particle diameter in HPLC results in increased column efficiency. use of small particles (<2 urn), however, requires p.essu.es beyond the traditional 6,000 psi of conventional pumping devices. Instrumental development in recent years has resulted in pumping devices capable of handling the requirements of columns packed with small particles. The staggered parallel HPLC system consists of four fully independent binary HPLC pumps, a modified auto sampler, and a series of switching and selector valves all controlled by a single computer program. The system improves sample throughput without sacrificing chromatographic separation or data quality. Sample throughput can be increased nearly four-fold without requiring significant changes in current analytical procedures. The process of Bioanalytical Method Validation is required by the FDA to assess and verify the performance of a chronlatographic method prior to its application in sample analysis. The validation should address the selectivity, linearity, accuracy, precision and stability of the method. This presentation will provide all overview of the work required to accomplish a full validation and show how a chromatographic method is suitable for toxirokinetic sample analysis. A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method developed to quantitate drug levels in dog plasma will be used as an example of tile process.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.359-365
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• 2017

Impermeable surfaces such as transportation land uses including roads and parking lots accumulate high heavy metals and particulate matters concentration especially during dry season which worsens the river water quality and distort the water circulation system during rainfall events. Recently, the government has been promoting policies to install Low Impact Development (LID) facilities such as permeable pavements or grass blocks in parking lots or pavements. However, transition of asphalt-paved surfaces to permeable pavement generated asphalt wastes which are detrimental to the environment and has cost implications due to its removal and disposal. Therefore this study was conducted to provide a method of constructing a cost-effective permeable pavement to reduce waste generation and cost. In this study, comparative analysis of the water circulation capacity and economic efficiency of the traditional construction method and new method proposed in this study through the lab-scale experiment. The proposed method was to make holes in existing asphalt pavements, layout geotextile fabric and permeable base media such as sand before compaction. After compaction, layout grass blocks on the compacted base media then layout sand in between each grass blocks before compaction. Apparently, there was no significant difference between the traditional installation method of permeable pavement and the proposed method in this study considering surface runoff, infiltrated volume, stored volume, and rainfall-runoff delay time. The proposed method in this study generated 86% less wastes compared to the traditional installation method and has 70% cost reduction considering asphalt removal and disposal. The construction method proposed in this study yielded similar performance compared to the traditional installation method and water circulation effect, but was proven to be less complicated and economical.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.3
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• pp.161-165
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• 2009

To evaluate the efficiency of the decontamination plant for the removal of uranium compounds deposited on the internal surface of $UF_6$ cylinder for its reuse, two demonstration tests of the plant with different ratio of ${Na_2}{CO_3}$ and ${H_2}{O_2}$ were carried out, and each test had 5 steps. The main chemical form removed by the tests was to be identified as ${Na_4}{UO_2}(CO_3)_3$. More than 50% of uranium was removed by water of the first step, and at the following steps the removal amounts were exponentially decreased. On the other hand, the result shows that the injected amount of ${Na_2}{CO_3}$, compared with that of the removed uranium, was stoichiometrically excessed. This suggests that the injected amounts of ${Na_2}{CO_3}$, the generation rate of decontaminated waste, and the decontamination steps could be reduced by a process optimization of the plant.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.67-71
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• 2013

$FeCl_3$ has been used as an etchant for metal etching such as Fe, Cu, and Al. In the process of metal etching, $Fe^{3+}$ is reducted to $Fe^{2+}$ and the etching rate becomes slow and etching efficiency decreased. Waste $FeCl_3$ etchant needs to be regenerated because of its toxicity and treatment cost. In this work, HCl was initially mixed with the waste $FeCl_3$ and then, strong oxidants, such as $O_2$ and $H_2O_2$, were added into the mixed solution to regenerate the waste etchant. During successive etching and regeneration processes, oxygen-reduction potential (ORP) was continuously measured and the relationship between ORP and etching capability was investigated. Regenerated etchant using a two vol% HCl of the total etchant volume and a very small amount of $H_2O_2$ was very effective in recovering etching capability. During the etching-regeneration process, the same oxygen-reduction potential variation cannot be repeated every cycle since concentrations of $Fe^{2+}$ and $Fe^{3+}$ ions were continuously changed. It suggested that the control of etching-regeneration process based on the etching time becomes more efficient than that of the process based on oxygen reduction potential changes.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.491-495
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• 2005

Vanadium pentoxide xerogels with a doping ratio of $Al/V_2O_5$ ranging from 0.01 to 0.05 were synthesized by doping Al into $V_2O_5$ xerogel via the sol-gel process. By using the synthesized $Al_xV_2O_5$, the $Li/Al_xV_2O_5$ cells were assembled to investigate the chemical and electrochemical properties. Surface morphology of the $Al_xV_2O_5$ xerogel showed an anisotropic corrugated sheet-like matrix, and the interlayer distance was about $11.5{\AA}$. The IR spectra of the $Al_xV_2O_5$ revealed that the doped Al was coordinated to the vanadyl group in $V_2O_5$. The $Al_xV_2O_5$ xerogels showed enhanced reversibility and energy density compared with the $V_2O_5$ xerogel. The specific capacity of the $Al_{0.05}V_2O_5$ xerogel was more than 200 mAh/g at 10 mA/g discharge rate, and cycle efficiency was about 90% after the 31st cycling test between 1.9 V and 3.9 V.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.534-538
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• 2017

In this study, the molecular weight controlled pitches derived from pyrolyzed fuel oil (PFO) were prepared using solvent extraction and were carbonized. Electrochemical characteristics of lithium battery anode materials were investigated using these petroleum pitches. Three pitch samples prepared by the thermal reaction were 3903 (at $390^{\circ}C$ for 3 h), 4001 (at $400^{\circ}C$ for 1 h) and 4002 (at $400^{\circ}C$ for 2 h). The prepared hexane insoluble pitches were analysed by XRD, TGA, SEM and Gel permeation Chromatography (GPC). The electrochemical characteristics of the PFO-derived pitch as an anode material were investigated by constant current charge/discharge, cyclic voltammetry and electrochemical impedance tests. The coin cell using pitch (4001) and the electrolyte of $LiPF_6$ in organic solvents (EC : DMC = 1 : 1 vol%, VC 3 wt%) has better initial capacity (310 mAh/g) than that of other pitch coin cells. Also, this carbon anode showd a high initial efficiency of 82%, retention rate capability at 2 C/0.1 C of 90% and cycle retention of 85%. It was found that modified pitches improved the cycling and rate capacity performance.