• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.4 no.2
• /
• pp.95-102
• /
• 2006

Alpha spectrometry was studied for the determination of $^{237}Np$ in spent nuclear fuel samples. The optimum condition for the electrodeposition of $^{237}Np$ was obtained as follows : for $1{\sim}1.5$ hour of deposition time, at the current intensity of $1.2{\sim}1.5$ A and at sodium sulfate electrolyte without organic additive. The deposition yield and its reproducibility on $^{237}Np$ was decreased as the amount of $^{237}Np$ decreased from 4.16 Bq down to 0.0264 Bq(1ng). The recovery yield of $^{237}Np$ determined by alpha spectrometry after separation in synthetic solution was $98.8{\pm}5.1%$(n=4). The contents of $^{237}Np$ in spent nuclear fuel samples were determined and the result showed an agreement within 10% of a difference between the measurement and the calculation.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.3
• /
• pp.568-577
• /
• 2015

To protect skin problems, new natural material alternative to synthetic antioxidants has been extensively selected from natural sources such as plants, animals, and microorganisms. Poncirus trifoliata of those has been widely used as treatment of allergy, chronic inflammatory diseases, and natural antioxidant. In recent days, microbial fermentation to natural products has been reported to increase feasibly their bioavailability. Accordingly, we performed the fermentation using hot water extract of Poncirus trifoliata by isolated Leuconostocs sp. strain JYK and investigated the change of antioxidative activity. Antioxidative material such as hesperidine naringine, imperatorin, and luteolin was found in hot water extract of Poncirus trifoliata. Total phenolics compounds and flavoniods in hot water extract were $71.2{\pm}4.58GAE(mg/g)$ and $25.1{\pm}4.12$ hesperidine(mg/g), respectively. After fermentation, their values were $89.2{\pm}13.47GAE(mg/g)$ and $31.0{\pm}4.06$ hesperidine(mg/g), respectively. After fermentation, ABTS[2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)] and DPPH(1,1-diphenyl-2-picrylhydrazyl) radical were highly enhanced from $70.2{\pm}9.01$ to $86.2{\pm}3.72$ and $18.7{\pm}1.81$ to $26.6{\pm}4.06$, respectively. Thus microbial fermentation offers a tool to further increase the bioactive potential of Poncirus trifoliata.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.12
• /
• pp.840-846
• /
• 2012

Global climate changes caused by $CO_2$ emissions are currently debated around the world; green sources of energy are being sought as alternatives to replace fossil fuels. The sustainable use of biogas for energy production does not contribute to $CO_2$ emission and has therefore a high potential to reduce them. Catalytic steam reforming of a model biogas ($CH_4:CO_2$ = 60%:40%) is investigated to produce $H_2$-rich synthesis gas. The biogas utilized 3D-IR matrix burner in which the surface combustion is applied. The ruthenium catalyst was used inside a reformer. Parametric screening studies were achieved as Steam/Carbon ratio, biogas component ratio, Space velocity and Reformer temperature. When the condition of Steam/Carbon ratio, $CH_4/CO_2$ ratio, Space velocity and Refomer temperature were 3.25, 60% : 40%, $14.7L/g{\cdot}hr$ and $550^{\circ}C$ respectively, the hydrogen concentration and methane conversion rate were showed maximum values. Under the condition mentioned above, $H_2$ yield, $H_2$/CO ratio, CO selectivity and energy efficiency were 0.65, 2.14, 0.59, 51.29%.

• The Korean Journal of Pesticide Science
• /
• v.14 no.3
• /
• pp.272-279
• /
• 2010

KNF-1002, a new fungicide candidate, is very effective for protecting crops against plant diseases, but its curative activity against barley powdery mildew is negligible due to its weak penetrability into plant leaf. To select the most efficient activator and, at the same time, spreade-sticker, foliar uptake and deposit of aqueous spray formulations containing non-ionic or anionic surfactants and fatty acid alkyl esters as an adjuvant were assessed by using Congo Red method. In the absence of activator, only 0.1% of the applied active ingredient was absorbed by barley leaves 24 h after spraying with an aqueous acetone containing KNF-1002 100 mg/L. But, non-ionic surfactants (500 mg/L), such as heptaethylene glycol monooctadecenyl ether (OE-7), dodecaethylene glycol monohexadecyl ether (CE-12), so facilitated KNF-1002 uptake that the uptake was increased up to 48.5%. To wheat plant, the addition of surfactants in spray solution of KNF-1002 also increased the foliar uptake and deposition of active ingredient, but its efficiency varied according to the kind of fatty alcohol moiety of polyoxyethylene surfactant. KNF-1002 formulations containing nonaethylene glycol monododecyl ether (LE-9) as an activator and spreader-sticker showed remarkable increases of fungicidal activity against barley powdery mildew.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.12
• /
• pp.2213-2220
• /
• 2017

This paper proposes an efficient approach for hardware implementation of moving object detection (MOD) processor using effective Gaussian mixture learning (EGML)-based background subtraction method. Arithmetic units used in background generation were implemented using LUT-based approximation to reduce hardware complexity. Hardware resources used for both background subtraction and Gaussian probability density calculation were shared. The MOD processor was verified by FPGA-in-the-loop simulation using MATLAB/Simulink. The MOD performance was evaluated by using six types of video defined in IEEE CDW-2014 dataset, which resulted the average of recall value of 0.7700, the average of precision value of 0.7170, and the average of F-measure value of 0.7293. The MOD processor was implemented with 882 slices and block RAM of $146{\times}36kbits$ on Virtex5 FPGA, resulting in 60% hardware reduction compared to conventional design based on EGML. It was estimated that the MOD processor could operate with 75 MHz clock, resulting in real-time processing of $800{\times}600$ video with a frame rate of 39 fps.

• Resources Recycling
• /
• v.14 no.3
• /
• pp.16-36
• /
• 2005

The quantity of passenger cars in industrial countries has been significantly increased in recent years. According to prognoses, this tendency is likely to continue in the forthcoming future. As a direct consequence, an increase of End-of Life-Vehicles (ELV) will confront us with the problem of "ELV-Recycling". In order to cope with this situation, the European regulation for the treatment of End-of-Life-Vehicles (09/2000) has been transferred to national law in Germany (ELV-Regulation from 1 July 2002). The long term aim is to reduce residues from the ELV-treatment to less than 5 wt% from 30 wt% within the next 10 years (2015). For that reason, there is a need for innovative and more efficient recycling techniques tailored to future materials in automobiles. The design process at automotive industry is continuously changing due to the strong demand on optional equipment and new technical solutions for fuel saving. Light materials, such as aluminum and plastics, consequently become more important and cause a decrease of ferrous metals. Since plastic materials are often used as compounds, a separation into initial material types by means of mechanical recycling methods is not possible. For that reason, efficient recycling can only be realized by introducing recycling-friendly car designs. In the end an integrated approach of auto makers and recycling industry is of decisive significance for the fulfillment of future regulations.

• Resources Recycling
• /
• v.19 no.5
• /
• pp.31-43
• /
• 2010

To fabricate porous SiC candle filter for filtration facility of the IGCC system, the candle type filter preforms were fabricated by ramming and vacuum extrusion process. A commercially available ${\alpha}$-SiC powders with various particle size were used as starting raw materials, and $44\;{\mu}m$ mullite, $CaCO_3$ powder were used as non-clay based inorganic sintering additive. The candle typed preforms by ramming process and vacuum extrusion were sintered at $1400^{\circ}C$ for 2h in air atmosphere. The effect of forming method and particle size of filter matrix on porosity, density, strength (flexural and compressive strength) and microstructure of the sintered porous SiC candle tilters were investigated. The sintered porous SiC filters which were fabricated by ramming process have more higher density and strength than extruded filter in same particle size of the matrix, and its maximum density and 3-point bending strength were $2.00\;g/cm^3$ and 45 MPa, respectively. Also, corrosion test of the sintered candle filter specimens by different forming method was performed at $600^{\circ}C$ for 2400h using IGCC syngas atmosphere for estimation of long-term reliability of the candle filter matrix.

• Polymer(Korea)
• /
• v.30 no.3
• /
• pp.230-237
• /
• 2006

Copolymers(HSA-98-20, HSA-98-0, HSA-98+20) which we acrylic resin containing 80% solid content were synthesized by the reaction of monomers, including methyl methacrylate, n-butyl acrylate, and 2-hydroxyethyl acrylate with a functional monomer, acetoacetoxyethyl methacrylate (AAEM), which nay give improvements in cross-linking density and physical properties of films. The physical properties of prepared acrylic resins, containing AAEM, are as follows viscosities, $1420\sim5760cps$ ; number average molecular weight, $2080\sim2300g/mol$; polydispersity index, $2.07\sim2.19$ ; and conversions, $88\sim93%$. In the next step, high-solid coatings (HSA-98-20C, HSA-98-0C, HSA-98+20C) were prepared by the curing reaction between acrylic resins containing 80% solid content and isocyanate at room temperature. Various properties were examined on the film coated with the prepared high-solid coatings. The introduction of AAEM to the coatings enhanced the abrasion resistance and solvent resistance, which indicated the possible use of high- solid coatings for top-coating materials of automobile. Since the curing by viscoelastic measurement occurred in sequence of HSA-98+20C > HSA-98-0C > HSA-98-20C, it was concluded that the curing rates became faster with incresing $T_g$ values.

• Polymer(Korea)
• /
• v.31 no.6
• /
• pp.505-511
• /
• 2007

Poly(lactide-co-glycolide)(PLGA) and hyaluronic acid (HA) has been widely used as biocompatible scaffold materials to regenerate tissue. In this present study, we fabricated microporous PLGA and HA loaded PLGA scaffolds by a emusion freeze-drying method. In order to confirm that the release profile of cytokine or water-soluble drugs, we manufactured the granulocyte macrophage colony stimulating factor(GM-CSF) loaded PLGA and HA-PLGA scaffold. All scaffolds were characterized using scanning electron microscope(SEM), mercury porosimeter and wettability measurement. Cell proliferation and viability were assessed by a 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) test. The porosity of HA-PLGA scaffold was greater than 95% with the total pore area of $261\;m^2/g$. The HA-FLGA scaffold exhibited well interconnected pores to allow greater cell adhesion and prolixferation. It was proven by higher cell viability in the HA-PLGA scaffold than PLGA alone. This may be due to the enhanced natural properties and higher water retention capacity of HA.

• Polymer(Korea)
• /
• v.36 no.3
• /
• pp.326-331
• /
• 2012

In this study, expanded poly(tetrafluoro ethylene) (ePTFE) graft was modified to be used as a hemodialysis vascular access. Biodegradable poly(D,L-lactide-$co$-glycolide) (PLGA) was coated onto the inner surface of ePTFE graft with paclitaxel, which is often used as an anti-cancer agent and for reducing neointimal hyperplasia. Surface characterization before and after PLGA coating was carried out by SEM and ATR-FTIR. Porous sturcture of ePTFE was maintained after coating of PLGA solution. The amounts of coated PLGA and paclitaxel determined by ATR-FTIR and HPLC were 1.96 and 0.263 mg/$cm^2$, respectively. Young's modulus was decreased and tensile strength was increased by PLGA coating. Released paclitaxel as a function of incubation time was monitored by HPLC. Approximately 35% of coated paclitaxel was released steadily for 4 weeks with the biodegradation of PLGA. From these results, it is expected that the effect of paclitaxel on reducing neointimal hyperplasia and stenosis is maintained for a long time.