• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.21-30
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• 2015

Ceramic foams are prepared as positive images corresponding to a plastic foam structure which exhibits high porosities (85-90%). This structure makes the ceramic foams attractive as a catalyst in a dry reforming process, because it could reduce a high pressure drop problem. This problem causes low mass and heat transfers in the process. Furthermore, the reactants would shortly contact to catalyst surface, thus low conversion could occur. Therefore, this research addressed the preparation of dry reforming catalysts using a sol-gel catalyst preparation via a polymeric sponge method. The specific objectives of this work are to investigate the effects of polymer foam structure (such as porosity, pore sizes, and cell characteristics) on a catalyst performance and to observe the influences of catalyst preparation parameters to yield a replica of the original structure of polymeric foam. To accomplish these objectives industrial waste foams, polyurethane (PU) and polyvinyl alcohol (PVA) foams, were used as a polymeric template. Results indicated that the porosity of the polyurethane and polyvinyl alcohol foams were about 99% and 97%. Their average cell sizes were approximate 200 and 50 micrometres, respectively. The cell characteristics of polymer foams exhibited the character of a high permeability material that can be able to dip with ceramic slurry, which was synthesized with various viscosities, during a catalyst preparation step. Next, morphology of ceramic foams was explored using scanning electron microscopy (SEM), and catalyst properties, such as; temperature profile of catalyst reduction, metal dispersion, and surface area, were also characterized by $H_2-TPR$ and $H_2-TPD$ techniques, and BET, respectively. From the results, it was found that metal-particle dispersion was relatively high about 5.89%, whereas the surface area of ceramic foam catalysts was $64.52m^2/g$. Finally, the catalytic behaviour toward hydrogen production through the dry reforming of methane using a fixed-bed reactor was evaluated under certain operating conditions. The approaches from this research provide a direction for further improvement of marketable environmental friendly catalyst production.

• Journal of Adhesion and Interface
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• v.16 no.2
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• pp.69-75
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• 2015

Stone board for the rock bed was needed to reduce weight using thin thickness and reinforced materials. In this work, stone/wood board for rock bed was studied. Stone and wood were attached to reduce total weight of stone for rock bed. For reinforcing wood heat treatment method was used to change surface and mechanical properties. Mechanical strength of heat treated wood increased more than neat condition. The optimum heat treatment condition was set on $100^{\circ}C$ under tensile, flexural loads whereas surface energy was also obtained by contact angle measurement. Optimum adhesive condition was to get the maximum adhesion between stone and wood. Lap shear test was performed for stone/wood board with different adhesives such as amine type epoxy, polyurethane, chloro-rubber and vinyl chloride acetate type. Fracture surface of lap shear test was shown at wood fracture part on stone using amine type epoxy adhesive. It was found that for high adhesion between stone and wood the optimum adhesive was epoxy type for the rock bed.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.553-558
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• 2003

The crystal structure of $[n-Bu_4N]_2[Mo_6O_{19}]$(TBAM) (n-Bu4N=tetrabutylammonium) has been determined by X-ray crystallography. It crystallizes in the monoclinic system, space group C2/c, with lattice parameters ${\alpha}$=16.314(5), b=17.288(5), c=17.776(4)${\AA}$ ${\beta}$=101.47(3), and Z=4. In $[Mo_6O{19}]^{2-}$ anion, Mo atoms occupy six vertices of octahedron and each Mo atom is coordinated by six oxygen atoms to adopt distorted octahedral coordination geometry. The average bond distance of Mo-Ot (terminal), Mo-Ob (bridged) and Mo-Oc (central) are 1.680 ${\AA}$, 1.931 ${\AA}$ and 2.325 ${\AA}$ respectively. In $[n-Bu_4N]^+$ cation, the N atom possesses a slightly distorted tetrahedral geometry. There are some potential extensive C-H ${\cdots}$ O hydrogen bonds in the lattice, by which connecte molecules and stabilize the crystal structure. Thermogravimetric analysis suggests that thermal decomposition of the title compound includes two transitions and it loses weight at 356.0 and 803.5 $^{\circ}$, respectively, and the residue presumable be $Mo_2O_2$. Accordingly, the title compound has high thermal stability.

• Membrane Journal
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• v.24 no.6
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• pp.463-471
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• 2014

While poly(styrene)-based anion exchange membranes have the advantage like easy and simple manufacturing process, they also possess the disadvantage of poor durability due to their brittleness. Acrylonitrile-butadiene rubber was used here as an additive to make the membranes have improved flexibility and durability. For the preparation of the anion exchange membranes, a PP mesh substrate was immersed into monomer solutions with vinylbenzyl chloride, styrene, divinylbenzene and benzoyl peroxide, then thermally polymerized & crosslinked. The prepared membranes were subsequently post-aminated using trimethylamine to result in $-N+(CH_3)_3$ group-containing composite membranes. Various contents of vinylbenzyl chloride and acrylonitrile-butadiene rubber were investigated to optimize the membrane properties and the prepared membranes were evaluated in terms of water content, ion exchange capacity and electric resistance. It was found that the optimized composite membranes showed higher IEC and lower electric resistance than a commercial anion exchange membrane(AMX) and have excellent flexibility and durability.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.3
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• pp.191-197
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• 2017

The Korea Atomic Energy Research Institute (KAERI) has developed a safeguards technology for pyroprocessing based on the Safeguards-By-Design (SBD) concept. KAERI took part in a Member-State Support Program (MSSP) to establish a pyroprocessing safeguards approach. A Reference Engineering-scale Pyroprocessing Facility (REPF) concept was designed on which KAERI developed its safeguards system. Recently the REPF is being upgraded to the REPF+, a scaled-up facility. For assessment of the nuclear-material accountancy (NMA) system, KAERI has developed a simulation program named Pyroprocessing Material Flow and MUF Uncertainty Simulation (PYMUS). The PYMUS is currently being upgraded to include a Near-Real-Time Accountancy (NRTA) statistical analysis function. The Advanced Spent Fuel Conditioning Process Safeguards Neutron Counter (ASNC) has been updated as Non-Destructive Assay (NDA) equipment for input-material accountancy, and a Hybrid Induced-fission-based Pu-Accounting Instrument (HIPAI) has been developed for the NMA of uranium/transuranic (U/TRU) ingots. Currently, performance testing of Compton-suppressed Gamma-ray measurement, Laser-Induced Breakdown Spectroscopy (LIBS), and homogenization sampling are underway. These efforts will provide an essential basis for the realization of an advanced nuclear-fuel cycle in the ROK.

• Quality Improvement in Health Care
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• v.9 no.2
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• pp.176-197
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• 2002

Backgound : This study is to suggest the standardized format of the clinical sheets and the standardized items of every clinical sheet. The standardization of the medical records will increase the faithfullnes of the contents in them and it will contribute to construct the good health information system. Method : From Jan. 1st. 2001 to March 31st 2001, we gathered as many paper clinical sheets as possible by every class of institutions to review the faithfulness of the clinical contents in them. Clinical sheets of 9 tertiary care hospitals, 6 general hospitals and 56 clinics were gathered. Two experienced medical record administrators reviewed them. The review focus was to check whether the items recommend by the hospital standardization review criteria and hospital service evaluation organization were appeared in the clinical sheets and whether the contents of every item were written. Results : Tertiary care hospitals; In case of administrative data, the contents were filled well if the items were fixed. The clinical data like C.C, history,physical examiniation were filled well, but if the items were not fixed, some items were omitted. The result is that more items are to be filled if they are fixed. General hospitals Administrative data were filled more than 50%. Final diagnosis was filled about 66.7%.But other clinical data were not filled well and not many clinical related items were appeared in the sheets.In the legal point of view, the reason for visiting hosptals or the right diagnosis, patient condition at discharge could not be confirmed well.In surgery cases, surgical procedures could not be confirmed well as many surgical related information(surgery time, fluids and blood, number of sponges, biopsy, etc) were omitted. Clinics More than 70% administrative data were filled and fixed as items. Among the clinical related data, laboratory result was the most credible data. But without the right diagnosis, drug orders were given and doctors' written signatures were not appeared over 96.4%. So the clinical sheets cannot be used as a legal document. Conculusion : There was a tendency that the contents were filled well if the items were fixed in the documents, We also suggest a clinical check list to review the completeness and faithfulness of the clinical sheets. If many hospitals use the suggested clincal check list and if they make the necessary items fixed in the clinical sheets, the quality of the medical record will increase dramatically.

• Microbiology and Biotechnology Letters
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• v.45 no.1
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• pp.71-80
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• 2017

Tea is the most popular beverage in the world. The three main types are green, black, and post-fermented. Post-fermented teas are produced by the microbial fermentation of sun-dried green tea leaves (Camellia sinensis). In this study, the composition of the bacterial communities involved in the production of traditional oriental post-fermented teas (Korean algacha, dancha, and Chinese pu-erh) were investigated using 16S rRNA gene analysis. The dominant microorganisms present in the post-fermented teas included the ${\alpha}$-proteobacteria Rhodobacteraceae and Sphingomonas, and the ${\gamma}$-proteobacteria Pantoea. Cluster analysis confirmed that the microbial populations present in both Korean and Chinese post-fermented teas grouped into the same class. Interestingly, the dominant microorganism present in the Korean post-fermented teas was a bacterium, while for the Chinese post-fermented tea, it was a fungus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.509-514
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• 1994

A processing method for fermented paste of favorable flavor and texture using pen shell by-product was investigated. The pen shell by-product was homogenized with the addition of water and hydrolyzed with $5\%$ of Protin P(105 PU/g) at $55^{\circ}C$ for 1 hour. Flavor of the hydrolysate could be improved by thermal treatment at $100^{\circ}C$ for 40 minutes with $10\%$ of invert sugar. $2\%$ of agar-agar and $6\%$ of starch added to hydrolysate emulsified by $8\%$ of polyglycerol condensed ricinoleate(PGDR) were significantly effective for the improvement of rheological properties such as hardness, springiness and chewiness of the fermented paste. $15\%$ of table salt was finally added to the product of fermented pen shell paste. The contents of moisture, protein, lipid, carbohydrate and salinity of the product were $62.7\%,\;3.2\%,\;4.4\%,\;10.6\%\;and\;15.6\%$, respectively. The major free amino acids were glutamic acid, arginine, aspartic acid, leucine, lysine, glycine and alanine. The product was stable for the storage of 60 days at $23{\pm}3^{\circ}C$ on bacterial growth.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.2
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• pp.89-96
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• 2009

As increasing the number of digital control devices installed on aircrafts and their transmission speed, various digital data buses have been introduced to provide reliable and high-speed characteristics. These characteristics of avionics data bus are highly related on the fault-tolerant performance which can make minimize jitter and loss during data transfer. In this paper, we concerned about a new traffic shaping scheme for increasing the reliability of Avionics Full Duplex Switched Ethernet (AFDX) systems based on ARINC 664 standard. We note that the conventional AFDX with a single regulator per virtual link system may produce aggregated traffics as the number of virtual links increasing. The aggregated traffic results in large jitters among frames. To remedy for the jitter and loss of data, we propose a dual regulator scheme for the AFDX system. The purpose of the additional regulator is to additionally regulate aggregated traffics from a number of per virtual link regulators. Using NS-2 simulator, we show that the proposed scheme provides a better performance than the single regulator one. It is worthwhile note that the proposed AFDX with Dual Regulator scheme can be employed to not only aircraft networks but other QoS sensitive networks for robot and industrial control systems.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.625-633
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• 2014

Mark III CCS plate is considered in this paper to perform its strength assessment. Mark III CCS plate is designed and constructed by stacking various non-metallic engineering materials such as plywood, triplex and reinforced PU foam that are supported by series of mastic upon inner steel hull structure. From the viewpoint of structural analysis, this plated structure is treated as a laminated anisotropic structure. Commercially available general purpose finite element analysis programs such as MSC PATRAN and MARC are used to develop the finite element (FE) model of the Mark III CCS plate. Because of the characteristics of LNG cargo that the Mark III CCS plate deals with, it is subjected to a wide range of temperature variations, i.e. about $-163^{\circ}C$ to $20^{\circ}C$. Different material properties of the Mark III CCS plate at these temperature levels are considered in the FE model. Using the developed FE model, strength assessment procedure is developed incorporating various anisotropic failure criteria such as Hashin, Hill, Hoffman, Maximum stress and Tsai-Wu. The strength assessment is performed within the initial failure state of the Mark III CCS plate and, as a result, failure details such as failure locations and loads are identified.