• Clean Technology
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• v.23 no.2
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• pp.163-171
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• 2017

Currently, researches on recycling and reuse of waste energetic materials have recently gained a great attention from advanced countries due to ever tightening environmental regulations. In this study, as a part of a recycling technology, the experiments and dynamic simulation of simulated moving bed (SMB) process were performed to efficiently separate TNT and RDX from their mixture, which are main components of ammunition. In order to determine the operation zone of SMB process, the retention times of TNT and RDX were measured using HPLC at different flow rates and the adsorption equilibrium of each component was obtained by using a moment method. According to the adsorption equilibrium and the triangle theory of SMB process, four operation points were determined and separation experiments were carried out by the SMB process using the solvent consisting of acetonitrile and water. Two different mixing ratios (6:4 and 1:1) of acetonitrile and water were chosen for the experiment due to the great impact of mixing ratio of the solvent on separation. The performance of SMB process was evaluated by purity, recovery, productivity and solvent consumption. Pure TNT and RDX were successfully obtained from the SMB process and the dynamic simulation for the SMB process agreed well with the experimental results. Therefore, the dynamic model could be applied for predicting the dynamic behavior of the SMB process and designing a large scale SMB process.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.148-148
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• 2013

스퍼터 이온펌프(Sputter Ion Pump)는 주로 화학흡착으로 동작하며 기계적 진동이 없고, 기름 등의 오염 물질을 배출하지 않으며, 수명이 길어 초고청정 진공이 요구되는 표면실험장치, 표면분석계, 입자가속기 등에서 널리 사용 되고 있다. 일정한 지름을 갖는 다수의 원통 양극과 그 양단에 두개의 음극판을 배치시킨 후, 양극과 음극 사이에 수 kV의 전압을 걸고 원통의 축방향으로 자장을 인가하면 페닝 방전이 발생한다. 냉음극에서 방출된 전자는 양극으로 비행하면서 가스를 이온화한다. 이온분자는 가스흡수성 게터재료로 된 음극에 충돌하여 스퍼터링을 일으키며 게터막를 주변에 증착시킨다. 이온 및 중성 가스는 게터 고체막 속에 주입 포획되는 형태로 배기된다. 스퍼터 이온펌프는 $10^{-5}$ Pa 부근에서 최대 배기속도를 가지며, 압력이 낮아질 수록, 특히 $10^{-10}$ Pa영역 이하에서는 그 배기속도가 급격히 저하되며, $10^{-10}$ Pa영역에서는 배기능력을 거의 상실한다. 따라서 스퍼터 이온펌프 단독으로 진공시스템을 배기할 때 도달압력은 $10^{-9}$ Pa 영역에 머무르게 되며, $10^{-10}$ Pa 이하의 극고진공을 얻기 위해서는, $10^{-8}$ Pa 이하의 압력에서 배기 속도가 압력과 무관한 흡착펌프(getter pump)와 이온펌프를 조합하여 사용한다. 본 실험에서는 $600^{\circ}C$ 이상의 온도로 진공로에서 탈개스시킨 진공용기를 배기속도 450, 60, 30, 20, 5, 3 l/s의 6종류의 이온펌프와 배기속도 400 l/s, 100 l/s의 non-evaporable getter (NEG) 펌프를 조합시켜 배기하여 그 배기 특성을 비교하였다. 도달 압력은 이온펌프의 배기속도가 클수록 낮아지는 경향을 보여주었다. 450 l/s 이온펌프와 400 l/s NEG를 조합하여 배기시킬 때 도달 압력은 ~$2{\times}10^{-10}$ Pa을 기록하여 가장 낮았으며, 3 l/s 이온펌프와 400 l/s NEG를 조합하였을 때는 $ 2{\sim}3{\times}10^{-8}$ Pa을 기록하였다. 450 l/s 이온펌프와 400 l/s NEG를 조합한 경우 잔류가스의 대부분이 수소였으나, 3 l/s 이온펌프와 400 l/s NEG의 조합한 경우에는 메탄의 잔류량이 수소 보다 많았다. 이 결과는 메탄을 배기하지 못하는 NEG의 배기 특성을 보완하기 위해서는 일정 배기속도 이상의 이온 펌프가 필요함을 보여준다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.600-601
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• 2021

식품제조 현장에서 유연포장을 수행하기 위해, 로봇이 다양한 제품들을 파지하거나 이송하는 작업이 필수적이다. 본 논문에서는 전통장류 식품제조에서 다양한 종류와 무게를 조합하는 혼합포장을 위해 전통장류 물체 영역 인식과 종류 인식을 수행한다. 이를 위하여, 대표적인 전통장류에 대해 종류를 분류하고, RGB-D 데이터를 입력으로 물체 영역과 종류 인식을 수행하는 딥러닝 네트워크를 학습한다. 실험 결과를 통해, 물체 영역의 중심점을 기반으로 흡착 기반 파지점을 선정할 수 있음을 확인한다.

• Journal of the Korean Chemical Society
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• v.31 no.4
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• pp.308-314
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• 1987

The adsorption behavior of some chelating agents on the Amberlite XAD-7 resin was studied to obtain the optimum conditions for the preparation of chelating agent-XAD-7 resins. The chosen chelating agents are cupferron (CP), diphenylcarbazone (DPC), salicylaldoxime (SAO), thiosalicylic acid (TSA), and dimethylglyoxime (DMG), which have been well known chelating agents to Cu(Ⅱ) and Ni (Ⅱ) ions. Among the chelating agent-XAD-7 resins, SAO-XAD-7 and DMG-XAD-7 resins were evaluated as appropriate impregnated resins by investigating their stabilities in the wide pH range and high abilities to adsorb Cu(Ⅱ) and Ni(Ⅱ) ions. The selective adsorption of Cu(Ⅱ) from Ni(Ⅱ) was possible by changing pH condition by SAO-XAD-7 resin. The adsorption capacities of SAO-XAD-7 and DMG-XAD-7 for Cu(Ⅱ) were $7{\times}10^{-3}mmol$ Cu(Ⅱ) per gram of resin and $2{\times}10^{-3}mmol$ Cu(Ⅱ) per gram of resin, respectively. The quantitative recovery of Cu(Ⅱ) adsorbed by the resin was demonstrated. The adsorption behavior of Cu(Ⅱ) and Ni(Ⅱ) by the single and mixed bed of chelating agent-XAD-7 resin was discussed.

• Resources Recycling
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• v.15 no.2 s.70
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• pp.50-57
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• 2006

Production of activated carbon from woody fish parking cases has been studied using waste sulfuric acid as an activating agent for the purpose or promoted recycling of woody fishing port wastes. The adsorption capacity of produced activated carbon was observed to increase with activation temperature and reached its maximum at ca. $650^{\circ}C$ under the experimental conditions. However, the adsorption capacity of activated carbon became deteriorated above this temperature due to the thermal degeneration of its structure. Optimal activation time was found to be about 120 minutes and 1:3 weight ratio of raw material and activating agent was appropriate for increased adsorption capacity of activated carbon under the conditions of $550^{\circ}C$ and 60 minutes of activation time. Regarding the effect of the concentration of activating agent on activation, ca. 1.2 M of sulfuric acid was observed to be proper for an optimal activation or raw material. Comparison of the activation power of sulfuric acid with nitric acid showed that sulfuric acid was superior to nitric acid, however, with regard to the yield of activated carbon there was no significant difference between the two activating agents. The degree of dispersion of carbon particles was shown to be relatively high in neutral condition and the produced activated carbon was considered to be effectively employed for the treatment of metal ions in wastewater due to its negative surface charge in aqueous condition.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.6
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• pp.423-430
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• 2013

In this research, a paramteric study to account for the effect of interfacial strength and nanotube agglomeration on the elastoplastic behavior of carbon nanotube reinforced polypropylene composites is performed. At first, the elastoplastic behavior of nanocomposites is predicted from molecular dynamics(MD) simulations. By combining the MD simulation results with the nonlinear micromechanics model based on the Mori-Tanaka model, a two-step domain decomposition method is applied to inversely identify the elastoplastic behavior of adsorption interphase zone inside nanocomposites. In nonlinear micromechanics model, the secant moduli method combined with field fluctuation method is used to predict the elastoplastic behavior of nanocomposites. To account for the imperfect material interface between nanotube and matrix polymer, displacement discontinuity condition is applied to the micromechanics model. Using the elastoplastic behavior of the adsorption interphase zone obtained from the present study, stress-strain relation of nanocomposites at various interfacial bonding condition and local nanotube agglomeration is predicted from nonlinear micromechanics model with and without the adsorption interphase zone. As a result, it has been found that local nanotube agglomeration is the most important design factor to maximize reinforcing effect of nanotube in elastic and plastic behavior.

• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.49-56
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• 2000

This study was designed to investigate the adsorption of heavy metal ions by untreated bark according to the treatment conditions of aqueous solution. The effect of temperature and pH of aqueous solution, particle size of bark, addition of light metal ions on the adsorption was examined, and the competition in adsorption among heavy metal ions was also evaluated. te The adsorption ratio of $Cu^{2+}$ and $Zn^{2+}$ increased with increasing themperature of solution from $-5^{\circ}C$ to $10^{\circ}C$ however, it was relatively constant at temperatures between $10^{\circ}C$ and $55^{\circ}C$. The adsorption ratio of $Cr^{6+}$ increased continuously with increasing the temperature of solution. The maximum adsorption ratio of $Cu^{2+}$, $Zn^{2+}$, and $Pb^{2+}$ was noted at pHs ranged 6 to 7; however, the adsorption ratio declined sharply on either sides of the optimum. The adsorption ratio of $Cr^{6+}$ decreased continuously with increasing the pH of solution. The adsorption ratio increased as decreasing the particle size of bark, and there was little differences in adsorption tendency between pine and oak bark. By the addition of $Ca^{2+}$ or $Mg^{2+}$(10~25 ppm), the adsorption ratio of $Cu^{2+}$ and $Zn^{2+}$ increased. An increase of the adsorption ratio was higher in oak bark than in pine bark. However, the adsorption ratio of $Pb^{2+}$ and $Cr^{6+}$ was not affected by the addition of light metal ions. As the mixed solution of 2 or 3 kinds of heavy metal ions($Cu^{2+}$, $Zn^{2+}$, $Pb^{2+}$) was treated with the untreated bark, the adsorption of $Zn^{2+}$ decreased considerably because of the competitive adsorption among heavy metal ions. Also the adsorption of $Cu^{2+}$ was more and less reduced. However the adsorption of $Pb^{2+}$ was not affected by the presence of other heavy metal ions.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1765-1775
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• 2000

The removal of radioactive organic iodide generated from high temperature process in nuclear facility was generally performed by silver ion-exchanged synthetic zeolite (AgX). The purpose of this study is to obtain fundamental data for the substitution of natural zeolite(NZ) in stead of synthetic zeolite as supporter for the removal of methyl iodide in high temperature conditions. Therefore, NZ was modified with NaCl, $NaNO_3$ solution, and the analysis of the physical or surface characteristics through XRD, SEM-EDAX, and BET analysis was performed. In order to obtain the optimal surface-modification condition of NZ, adsorption capacities at $150^{\circ}C$ on surface-modified silver ion-exchanged NZ prepared with the variation of solution concentration were evaluated. The optimal condition of surface modification is that concentration of $NaNO_3$ and $AgNO_3$ are 1N and 1.2N, respectively(namely Ag-SMNZ). The adsorption isotherm of methyl iodide on Ag-SMNZ in a range of $100^{\circ}C$ to $300^{\circ}C$ was obtained, which is similar to that of 13X, and the maximum adsorption amount of Ag-SMNZ reached approximately 50% that of AgX. It would be evaluated that the adsorption capacity at $150{\sim}200^{\circ}C$ is relatively higher than other temperature, and the chemisorption between silver and iodide is attributed to a strong binding even after desorption test.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.89-96
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• 2002

The adsorption characteristics of sodium chloride into Ca-alginate beads have been investigated and the result were as follows: Sodium chloride uptake by Ca-alginate beads increased with time. The highest uptake volume of sodium chloride was 4.2g after 10 minutes. The uptake volume by Fe, Ca, Ba, and Sr-alginate beads was 5.6g, 4.2g, 4.2g and 4.0g, respectively but in case of Fe-alginate beads, the induced hydrogel beads were very fragile and the strength of Fe-alginate beads were weaker than Ca- and Ba-alginate beads. Mg-alginate bead was not formed and Ca-, Ba- and Sr-alginate beads had a similar uptake volume about 4.2g, respectively. The uptake volume of sodium chloride by CaCl$_2$concentration(0.1M. 0.2M and 1M), curing solution, was 4.8, 4.2g and 4.1g, respectively. The uptake volume by sodium alginate concentration(0.6%, 1% and 2%) was 2.8g, 4.0g, and 4.4g, respectively and Ca-alginate bead size was not effected in uptake sodium chloride. The uptake rate on initial sodium chloride concentration(4%, 8%, 12% and 16%) was 30%, 28%, 27% and 25%, respectively. The uptake rate on basic pH(10.0) was higher than when compared to other neutral pH(6.8) and acidic pH(4.0). The initial uptake velocity of sodium chloride from immobilization beads with salt resistant bacteria was lower than that of non-immobilization beads. The uptake rate of sodium chloride was decreased according to elongation of curing time. Reusability of Ca-alginate beads was possible but according to reutilization, the salt uptake volume of beads was also decreased. The uptake volume of sodium chloride from Doengjang by Ca-alginate beads on time course(3, 6, 12, and 24 hour) was revealed 5g, 6g, 7g and 7g, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.399-399
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• 2010

Polyethylene glycol(PEG)은 강력한 단백질 및 세포흡착 억제력을 가지고 있어 다양한 생물학적 연구에 사용되고 있으나, 기판과의 결합력이 무척 약해 기판 위에 박막을 형성하기가 매우 어렵다는 문제점이 있다. 이번 연구에서는 capacitively-coupled plasma chemical vapor deposition(CCP-CVD)를 이용하여 PEG를 유리 기판 위에 플라즈마 중합하여 plasma-polymerized PEG(PP-PEG) 기판을 만들었다. PP-PEG 박막은 FT-IR, XPS, ToF-SIMS 분석을 통하여 PEG와 매우 유사한 화학적 조성을 가지고 있음을 확인할 수 있었다. 또한 PP-PEG 기판은 photolithography 방법을 이용하여 표면에 photoresist를 패턴한 뒤 아민작용기를 가지는 plasma-polymerized ethylenediamine (PPEDA)를 증착하여 표면이 amine/PEG로 패턴화된 박막 기판을 만들었다. 패턴된 기판에 단백질 및 세포를 고정화하였을 때, 아민 작용기가 노출된 부분에만 고정화가 나타나고 PP-PEG 영역에는 단백질 및 세포의 흡착이 효율적으로 억제되는 것을 형광측정 및 ToF-SIMS chemical imaging 방법을 이용하여 확인하였다. 이러한 바이오칩 제작기술은 단백질 및 세포 칩을 포함한 여러 분야에서 폭넓게 응용될 수 있을 것으로 기대된다.