• Polymer(Korea)
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• v.36 no.6
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• pp.727-732
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• 2012

Baroplastic poly(butyl acrylate) (PBA)/polystyrene (PS) blends were prepared by mixing PBA and PS emulsions synthesized by cationic and anionic surfactant, respectively. Interestingly, the heterocoagulation of nanoparticles have found to be affected strongly by emulsion concentration but the blends have been prepared with almost same compositions regardless of the amount of reactants. Utilizing this method, PBA/PS/Si hybrid nano-blends were prepared successfully via electrostatic attraction forces between PBA, PS and silica nanoparticles. The hybrid nano-blend having 2 or 5 wt% of silica was then processed to a semi-transparent film at $25^{\circ}C$ under 13.8 MPa for 10 min, which showed 3.0 MPa of tensile strength and 25 MPa of elastic modulus. Therefore, the heterocoagulation technique can be used for preparing baroplastics with uniform compositions of polymer and silica nanoparticles.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.55-64
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• 1996

In this paper, we analyze packaging data of th eprinted board assemblies (PBAs) of an ATM switching system (the first network test bed) by statistical methods and discuss the relation between devices packaging area of a PBA and power consumption by a regression nalysis method. As a result, we evaluate the maximum power consumption of the PBA. And, this paper presents a forecasting mehtod of the packagable maximum power consumption per a PBA when TTL devices are replaced by ASIC or FPGA ones in a PBA. And, we forecast the possibility of packaging ATM switch circuit packs in the near future form a statistical viewpoint. These evaluation and forecasting results can reduce much development cost and time because trial nd error will not be made using these useful data when phase II ATM switching system will be realized in the near future.

• Journal of KIISE:Databases
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• v.33 no.6
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• pp.620-630
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• 2006

Event-detection is an important application of sensor networks. Join operations can facilitate event-detection with a condition table predefined by a user. When join operations are used for event-detection, it is desirable, if possible, to do in-network join processing to reduce communication costs. In this paper, we propose an energy-efficient in-network join algorithm, called PBA. In PBA, each partition of a condition table is stored along the path from each node to the base station, and then in-network joins are performed on the path. Since each node can identify the parts to store in its storage by its level, PBA reduces the cost of disseminating a condition table considerably Moreover, while the existing method does not work well when the ratio of the size of the condition table to the density of the network is a little bit large, our proposed method PBA does not have such a restriction and works efficiently in most cases. The results of experiments show that PBA is efficient usually and especially provides significant cost reduction over existing one when a condition table is relatively large in comparison with the density of the network, or the routing tree of the network is high.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.9.1-9.5
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• 2015

Objectives Pyrethroid pesticides are among the most commonly using insecticides in South Korean households and have been the subject of considerable interest among public health professionals for their potential health effects. The objective of this study is to examine the level of urinary 3-phenoxybenzoic acid (3-PBA) among elementary students in South Korea. Methods We conducted a cross-sectional study to evaluate pyrethroid pesticide exposure levels by measuring the urinary metabolites of 3-PBA using a gas chromatographymass spectrometry method in March 2011. Study participants were 70 Asan-area and Incheon-area elementary students. Results All respondents had values above the detection limit, and the geometric means of 3-PBA in all children were $1.85{\mu}g/L$ and $1.46{\mu}g/g$ creatinine. Children with the top 10% urinary levels of 3-PBA were more likely to be girls, under nine years of age, living in a rural area, and living in a residential type apartment. Conclusions South Korean children have a higher concentration of urinary 3-PBA compared with those of other countries. Further research identifying exposure pathways and intervention efforts to reduce environmental pesticide use are needed in South Korea.

• KSBB Journal
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• v.18 no.6
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• pp.500-505
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• 2003

‘LK (lipoprotein kringle) 68’is a polypeptide of a modified ansiostatin consisting of three kringle structures that might be clinically useful as a potential cancer therapeutics. It can be produced by overexpressing it as inclusion body in recombinant E. coli. In this study, solid-phase refolding processes using packed bed adsorption (PBA) and expanded bed adsorption (EBA) column were carried out to compare their refolding yields with that of the conventional, solution-phase refolding process, For the solution-phase and the PBA-mediated processes employing Q-Sepharose, washed inclusion body was used as the starting material, whereas both washed inclusion body and E. coli homogenate were used for the EBA-mediated process employing streamline DEAE. On the final recovery LK68 per unit mass of wet cell basis, the EBA- and PBA-mediated processes showed about 2.7- and 1.5-fold higher yields, respectively, than the solution-phase refolding method. The solid-phase refolded LK68 demonstrated the same Iysine binding bioactivity and the retention time in the RP-and SEC-HPLC as those of the native protein.

• Journal of Microbiology
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• v.43 no.3
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• pp.295-300
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• 2005

In the present study, the performances of conventional purification methods, packed bed adsorption (PBA), and expanded bed adsorption (EBA) for the purification of the nucleocapsid protein (NP) of Newcastle disease virus (NDV) from Escherichia coli homogenates were evaluated. The conventional methods for the recovery of NP proteins involved multiple steps, such as centrifugation, precipitation, dialysis, and sucrose gradient ultracentrifugation. For the PBA, clarified feedstock was used for column loading, while in EBA, unclarified feedstock was used. Streamline chelating immobilized with $Ni^{2+}$ ion was used as an affinity ligand for both PBA and EBA. The final protein yield obtained in conventional and PBA methods was $1.26\%$ and $5.56\%$, respectively. It was demonstrated that EBA achieved the highest final protein yield of $9.6\%$ with a purification factor of 7. Additionally, the total processing time of the EBA process has been shortened by 8 times compared to that of the conventional method.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.360-365
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• 2007

The studies for the derivatization of 3-monochloropropane-1,2-diol (3-MCPD) were performed mainly as acylation with HFBI (heptafluorobutyrylimidazole), alkylation with PBA (phenylboric acid) and silylation with BSTFA (N,O-bis[trimethylsilyl]trifluoroacetamide). Also silylation with MTBSTFA(N-methyl-N-[tert.-butyldimethylsilyl] trifluoroacetamide) and acylation with MBTFA (N-Methyl-bis[trifluoro-acetamide]) were also considered. Except the TBDMS derivative of 3-MCPD, all the derivatives were detected well. The derivatives of 3-MCPD with HFBI, PBA and BSTFA showed below 10 ${\mu}g/kg$ which was sensitive enough to satisfy Korea maximum residue limit 0.3 mg/kg. Among the tested adsorbents, Extrelut20 and Florisil were evaluated as the proper adsorbents to eliminate the soy sauce matrix for 3-MCPD. Ethyl acetate was the most efficient eluent with good recovery rate. The desired surrogate compound and internal standard were 1,2-butanediol and 1,2-dibromo-3-chloropropane, respectively. The limit of detection for PB-MCPD and TMS-MCPD were 10.16 and 7.06 ${\mu}g/kg$ on GC/MSD, respectively. HFB-MCPD derivative showed the lowest detection limits 2.98 and 5.32 ${\mu}g/kg$ by GC/ECD and GC/MSD, respectively.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.67-74
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• 2016

The Prussian Blue Analogue(PBA) has three dimensional structure and the metal - organic framework material, and it has a variety configurations depending on the type of organic ligands. PBA has been receving an attention in the fields of biosensors, optical, catalytic, and hydrogen storage device. Also, it is an environmental friendly substance with a chemical stability. In addition, PBA is widely used in the filed of adsorption art since we can adjust the size of the fine pores. In this study, we synthesized $Mn_3[Fe(CN)_6]_2$, an organometallic framework chains by using a hydrothermal synthesis method. We used $K_4[Fe(CN)_6]$ and $MnCl_2$ as precursors. We also produced a manganese iron oxide, by baking the synthesized material. The effect of the size and shape of the particles was examined by controling pH of the precursor solution, the molar concentration of the precursor, and reaction time as the experimental variables. Synthesized absorbent was analyzed by XRD, SEM, FT-IR, UV-Vis, and TG / DTA to evaluate the adsorption properties of several dyes.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.420-423
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• 2008

This present work is to find optimum design of a NACA65 axial fan blade with weighted average surrogate model. The numerical analysis by Reynolds-average Navier-Stokes equations with shear stress turbulence(SST) is discretized by finite volume approximations and solved on hexahedral grids for flow analysis. The blade aerodynamic shape is modified by six design variables for the optimization. The blade profile as well as stacking line is modified to enhance blade total efficiency. Six design variables, airfoil maximum camber, maximum camber location, leading edge radius, trailing edge radius, lean angle at 50% span and lean angle at 100% span, are selected for blade profile to enhance the total efficiency. The PBA model which is basically weighted average of the basis surrogates is used to find the optimal design in the design space from the constructed response surface model for the objective function. By the optimization, the total efficiency is increased by 1.4%.

• Journal of Korean Society of Transportation
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• v.18 no.5
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• pp.99-107
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• 2000

Path-based assignment(PBA) is valuable to dynamic traffic control and routing in integrated ITS framework. As one of widely studied PBA a1gorithms, Gradient Projection(GP) a1gorithm typically fields rapid convergence to a neighborhood of an optimal solution. But once it comes near a solution, it tends to slow down. To overcome this problem, we develop more efficient path-based assignment algorithm by combining Conjugate Gradient method with GP algorithm. It determines more accurate moving direction near a solution in order to gain a significant advantage in speed of convergence. Also this algorithm is applied to the Sioux-Falls network and verified its efficiency. Then we demonstrate that this type of method is very useful in improving speed of convergence in the case of user equilibrium problem.