• Membrane and Water Treatment
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• v.3 no.3
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• pp.181-200
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• 2012

At present water crisis is not an issue of scarcity, but of access. There is a growing recognition of the need for increased access to clean water (drinkable, agricultural, industrial use). An encouraging number of innovative technologies, systems, components, processes are emerging for water-treatment, including new filtration and disinfectant technologies, and removal of organics from water. In the past decade many methods have been developed. The most important membrane-based water technologies include reverse osmosis (RO), ultrafiltration (UF), microfiltration (MF), and nanofiltration. Beside membrane based water-treatment processes, other techniques such as advanced oxidation process (AOP) have also been developed. Some unconventional water treatment technology such as magnetic treatment is also being developed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.26.2-26
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• 2001

It is known that Volterra kernel model can represent a wide variety of nonlinear chemical processes. But almost all Volterra kernel models which appeared in the literature are up to second order, because it was difficult to measure higher order Volterra kernels. Kashiwagi has recently shown a method for measuring Volterra kernels up to third order using pseudorandom M-sequence signals. In this paper, the authors verified the applicability of this method for chemical processes using polymerization reactor simulation. Also, the authors have recently proposed a practical Identification method for chemical processes, which is based on the combination of off-line nonlinear identification and on-line linear identification. This method is also applied to the identification of polymerization reactor, and we obtained ...

• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1099-1114
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• 2006

Our studies in the area of single electron transfer (SET) photochemistry have led to the discovery of efficient processes, in which regioselective formation of carbon-centered radicals takes place by nucleophile assisted desilylation of $\alpha$-trialkylsilyl substituted ether, thioether, amine and amide centered cation radicals. The rates of bimolecular desilylation of the intermediate cation radicals exceed those of other cation radical $\alpha$-fragmentation processes (e.g.,-deprotonation). This sereves as the basis for the design of highly regioselective, SET-induced photomacrocyclization reactions of polyether, polythioether, polyamide, and polypeptide linked phthalimides. Photocyclization reactions of trimethylsilyl-terminated substrates in these families are unique in that they produce polyfunctionalized macrocyclic substances in a highly efficient and regioselective manner. In addition, our studies in this area have led to important information about the factors that govern chemical and quantum efficiencies that should be applicable to a wide variety of redox processes promoted by SET from substrates containing more than one electron donor site.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.2
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• pp.246-263
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• 2011

Mankind has just begun to recognize that the most crucial factor to achieve the sustainable society in the future is green technology. Most countries support the development of green technology to prevent catastrophes from global warming, mainly in the areas of reducing carbon dioxide from the atmosphere. However, most products we consume in everyday life are produced through chemical processes, and we often oversee the fact that the huge amount of waste and energy during these chemical processes will seriously influence our goal to achieve our future society sustainable. Thus the technologies to minimize the amount of disposed waste and energy consumption during chemical processes may be more important than to reduce the greenhouse gases. In this regard this review introduces the recent status of green chemistry and future prospects in order to help our chemists and engineers establish research projects based on the green chemistry principles.

• Clean Technology
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• v.5 no.1
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• pp.62-77
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• 1999

Semiconductor industry has rapidly grown because of the need from electronic and computer industries. However the global environmental regulations for various hazardous chemical compounds, which are indispensably used in semiconductor manufacturing process, are getting stronger. The semiconductor industries should develop the cleaner technologies in order to both lead the future world market and avoid the regulations form environmentally developed countries. In this paper, cleaner technologies for semiconductor cleaning processes are surveyed, such as gas phase process, UV process, and plasma process. Advantages and disadvantages of these processes are discussed.

• Textile Coloration and Finishing
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• v.17 no.6 s.85
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• pp.20-26
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• 2005

For developing digital printing textiles, special pretreatment processes are necessary. These processes include developing formulation of coating agent and coating processes. The pretreatment were investigated with the variation concentration of anti-migration agent, fixation chemical etc.. The printing qualities according to pretreatment conditions were studied with color yield, printed capital letter sharpness and washing fastness. It was observed that the concentration of anti-migration agent, fixation agent(alkali) was closely related to printing qualities. For developing industrial technology of cellulosic digital printing textiles, optimum viscosity of pretreatment coating formulation is very important factor.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.58-63
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• 1993

Recently, a large amount of flammable or explosive materials have been handled or stored in chemical industries. H the equipments fail or the materials release in consequence of operation errors, fire and explosion could occur to them. Thus, risk assessment using quantification of risks is very important when design of processes and modifications of installed processes are performed. The purpose of this study is to develop the program for fire and explosion index in order to quantify the expected damage of fire and explosion incidents in chemical plants, to identify equipment that would be likely to contribute to the creation or escalation of an incident, to comunicate the potential fire and explosion risk to management and to account of damage cost.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.470-472
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• 1995

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.419-424
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• 2016

$H_5PMo_{10}V_2O_{40}$ ($PMo_{10}V_2$) catalyst chemically immobilized on sulfur-containing mesoporous carbon (S-MC) was prepared, and it was applied to the benzyl alcohol oxidation reaction. S-MC was synthesized by a templating method using SBA-15 and p-toluenesulfonic acid as a templating agent and a carbon precursor, respectively. S-MC was then modified to have a positive charge, and thus, to provide sites for the immobilization of $PMo_{10}V_2$. By taking advantage of the overall negative charge of $[PMo_{10}V_2O4_{40}]^{5-}$, $PMo_{10}V_2$ catalyst was immobilized on the S-MC support as a charge matching component. It was revealed that $PMo_{10}V_2$ species were finely and molecularly dispersed on the S-MC via chemical immobilization. In the vapor-phase oxidation of benzyl alcohol, $PMo_{10}V_2$/S-MC catalyst showed higher conversion of benzyl alcohol and higher yield for benzaldehyde and benzoic acid than unsupported $PMo_{10}V_2$ catalyst. The enhanced catalytic performance of $PMo_{10}V_2$/S-MC was due to fine dispersion of $PMo_{10}V_2$ species on the S-MC via chemical immobilization.

• Macromolecular Research
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• v.15 no.3
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• pp.221-224
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• 2007

A silica-magnesium bisupport (SMB) was prepared by a sol-gel method for use as a support for a metal-locene/Ziegler-Natta hybrid catalyst. The prepared $rac-Et(Ind)_2ZrCl_2/TiCl_4$/MAO(methylaluminoxane)/SMB catalyst was applied to the copolymerization of ethylene with l-hexene using a variable triethylaluminum (TEA)/transition-metal (Ti) ratio and fixed MAO/transition-metal (Zr) ratio. The effect of the Al(TEA)/Ti ratio on the physical properties and chemical composition distributions (CCDs) of the ethylene-hexene copolymers produced by the hybrid catalyst was investigated. In the ethylene-hexene copolymers, two melting temperatures attributed to the metal-locene and Ziegler-Natta catalysts were clearly observed. The number of CCD peaks was increased from six to seven and the temperature region in which the peaks for the short chain branches of the ethylene-hexene copolymer were distributed became lower as the Al(TEA)/Ti ratio was increased from 300 to 400. Furthermore, the temperature regions corresponding to the lamellas in the copolymer became lower and those corresponding to the small lamellas in the copolymer became higher as the Al(TEA)/Ti ratio was increased from 300 to 400. In the copolymer produced with Al(TEA)/Ti = 500, however, only four CCD peaks were observed and the short chain branches were poorly distributed.