• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.1041-1043
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• 2000

We present the effects of temperature (between 10 K and 298 K) and of hole concentration on the frequency and intensity of characteristic phonons in polycrystalline $La_2CuO_4-related$ compounds using FT-IR spectros-copy. The influences of the concentration of carrier doped on the phonon modes are prominent in the IR spectra of $La_2CuO_4-related$ compounds. For $La_2-xSrxCuO_4({\chi}=$ 0.00, 0.03, 0.07, 0.10, and 0.15) and electrochemically (or chemically) oxidized $La_2CuO_4$, the intensities of the transverse oxygen mode around 680cm $-^1$ which cor-responds mainly to Cu-O(1) stretching vibration in the basal plane of CuO6 octahedron, are decreased and dis-appeared depending on the Sr-substitution rate and the amount of excess oxygen, while the longitudinal oxygen mode around 510 cm $-^1$ corresponding to the Cu-O(2) stretching in the basal plane of CuO6 octahedron are near-ly invariable. In particular, after two cycles of cooling-heating between 10 K and 298 K for these sample, the phonons around 680 cm $-^1$ are blue shif 13-15 cm $-^1$, while the phonons around 510 cm $-^1$ are nearly constant. The introduction of the charge carrier by doping would give rise to the small contraction of CuO6 oc-tahedron as Cu $^3+$ requires a smaller site than Cu $^2+$, which results in the shortening of the Cu-O(1) bond length and Cu-O(2) bond length with the increased La-O(2) bond length. These results in the frequency shift of the characteristic phonons. The IR spectra of $La_2Li0.5Cu0.5O_4$ which exhibits an insulator behavior despite the $Cu^3+$ of nearly 100%, corroborate our IR interpretations. The mode around 710 cm $-^1$ corresponding to Cu-O(1) stretching vibration is still strongly remained even at low temperature (10 K). Thus, we conclude that the con-duction electrons formed within $CuO_2$ planes of $La_2CuO_4-related$ superconductors screen more effectively the transverse oxygen breathing mode around 680 $cm-^1$ depending on the concentration of the doped charge carrier in $La_2CuO_4-related$ compounds, which might use as a superconductivity probe.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.510-517
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• 2014

The purpose of this study was to analyze microbial hazards for cultivation environments and personal hygiene of strawberry and tomato farms at the growth and harvesting stage. Samples were collected from thirty strawberry farms and forty tomato farms located in Korea and tested for Staphylococcus aureus and Bacillus cereus. To investigate the change in the distribution of the S. aureus and B. cereus, a total of 4,284 samples including air born, soil or medium, mulching film, harvest basket, groves and irrigation water etc. were collected from eight strawberry farms and nine tomato farms for one year. As a result, total S. aureus and B. cereus in all samples were detected. Among the total bacteria of strawberry farms, S. aureus (glove: $0{\sim}2.1Log\;CFU/100cm^2$, harvest basket: $0{\sim}3.0Log\;CFU/100cm^2$, soil or culture media: 0~4.1 Log CFU/g, mulching film: $0{\sim}3.8Log\;CFU/100cm^2$), B. cereus (glove: $0{\sim}2.8Log\;CFU/100cm^2$, harvest basket: $0{\sim}4.8Log\;CFU/100cm^2$, soil or culture media: 0~5.3 Log CFU/g, mulching film: $0{\sim}4.5Log\;CFU/100cm^2$) were detected in all samples. The total bacteria of tomato farms, S. aureus (glove: $0{\sim}4.0Log\;CFU/100cm^2$, harvest basket: $0{\sim}5.0Log\;CFU/100cm^2$, soil or culture media: 0~6.1 Log CFU/g, mulching film: $0{\sim}4.0Log\;CFU/100cm^2$), B. cereus (glove: $0{\sim}4.0Log\;CFU/100cm^2$, harvest basket: $0{\sim}4.3Log\;CFU/100cm^2$, soil or culture media: 0~5.9 Log CFU/g, mulching film: $0{\sim}4.7Log\;CFU/100cm^2$) were detected in all samples. The contamination of S. aureus and B. cereus were detected in soil, mulching film and harvest basket from planting until harvest to processing, with the highest count recorded from the soil. But S. aureus and B. cereus were not detected in irrigation water samples. The incidence of S. aureus and B. cereus in hydroponics culture farm were less than those in soil culture. The amount of S. aureus and B. cereus detected in strawberry and tomato farms were less than the minimum amount required to produce a toxin that induces food poisoning. In this way, the degree of contamination of food poisoning bacteria was lower in the production environment of the Korea strawberry and tomato, but problems can be caused by post-harvest management method. These results will be used as fundamental data to create a manual for sanitary agricultural environment management, and post-harvest management should be performed to reduce the contamination of hazardous microorganisms.

• Polymer(Korea)
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• v.38 no.4
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• pp.510-517
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• 2014

A series of polyimide (PI) was prepared by reacting 4,4'-(hexafluoroisopropylidene)-diphthalic anhydride (6FDA) as the anhydride and bis(3-aminophenyl) sulfone (APS), bis[4-(3-aminophenoxy)-phenyl] sulfone (BAPS), 2,2-bis(4-aminophenyl)-hexafluoropropane (6FPD), 2,2-bis[4-(4-aminophenoxy)-phenyl]hexafluoropropane (6FBAPP), 2,2'-bis(trifluoromethyl)benzidine (TFDB), or 1,4-phenylenediamine (PDA) as the diamine. Residual stress behaviors were detected in-situ during thermal imidization of the polyimide precursors using a thin film stress analyzer (TFSA), and interpreted with respect to their morphology. According to the molecular orientation and packing order, the residual stress varied from 23.1 to 12.5 MPa, decreased with increasing chain rigidity. The thermal properties of the PI films were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and thermomechanical analysis (TMA). Their optical properties were measured by ultraviolet-visible spectrophotometer (UV-vis), and spectrophotometry. The properties of PI films were found to be strongly dependent upon the morphological structure. However, trade-offs between residual stress and optical properties were identified.

• Food Science and Preservation
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• v.23 no.4
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• pp.510-515
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• 2016

The purpose of study was to evaluate quality, physicochemical and sensory characteristics of acorn Sulgidduk by addition of acorn powder. Acorn Sulgidduk was processed rice powder which added 0, 5, 10, 15, and 20% of acorn powder. The moisture, crude lipid, and crude ash contents of Sulgidduk added with acorn powder was increased by addition amount of acorn powder, but carbohydrate and crude protein contents were decreased. By addition amount of acorn powder, soluble protein content of Sulgidduk were increased, but reducing sugar content were decreased. The L values of Sulgidduk were decreased by addition amount of acorn powder, but increased the a and b values. The hardness, adhesiveness, cohesiveness, springness and chewiness were decreased by addition amount of acorn powder. The sensory test of Sulgidduk added 10% of acorn powder showed the best score in overall preference. Therefore, these results suggested that Sulgidduk added 10% of acorn powder could be applied for produce of acorn Sulgidduk.

• Membrane Journal
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• v.25 no.4
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• pp.352-357
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• 2015

To determine the pervaporation separation characteristics of 1-butanol/water mixtures, PEI/PDMS hollow fiber membrane module commercialized by Airrane Co. was subjected to both lab and pilot tests. The 1% 1-butanol of 1-butanol/water feed mixture was used. The flux of $133g/m^2hr$ and separation factor of 23.4 at $30^{\circ}C$ were obtained whereas the $505g/m^2hr$ and 5.1 were measured at $50^{\circ}C$. When compared with the performance of the hollow fiber PDMS membrane by Nagasep Co., the higher flux of $10{\sim}20g/m^2hr$ was obtained by the module of Airrane Co. In order to realized the durability of Airrane Co. module, the long-term test of 35 days has been conducted and as a result, the flux $510{\sim}520g/m^2hr$ and separation factor 20~25 were maintained with the initial values.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.485-498
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• 2014

In this paper, vehicle-bridge interaction analysis under a series of moving vehicles to simulate a lane load was performed to estimate impact factor of the main cable, hanger and girder for the selected suspension bridges with 404m and 1545m main span. Korea Bridge Design Code(Limit State Design) was selected for the live model in which KL-510 truck was modeled 6-d.o.f. vehicle and a lane load was simulated by a series of single-axle vehicles. For the 404m main span bridge, hinge-type and floating-type girders at the tower were considered to examine the impact factor according to the connection and supporting type of the girders. The parameters considered herein are the types of live load-a truck only and a truck plus lane load, eccentricity of moving vehicles, road surface roughness and vehicle speed. The road surface roughness was randomly generated based on ISO 8608 and it was applied to the truck only. The impact factors were also evaluated by using the influence line method that is commonly used in cable-supported bridges and compared with those from vehicle-bridge interaction analysis.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.510-519
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• 2011

Intra mode decision is a useful coding tool in Distributed Video Coding (DVC) for improving DVC coding efficiency for video sequences having fast motion. A major limitation associated with the existing intra mode decision methods, however, is that its efficiency highly depends on user-specified thresholds or modeling parameters. This paper proposes an entropy-based method to address this problem. The probabilities of intra and Wyner?Ziv (WZ) modes are determined firstly by examining correlation of pixels in spatial and temporal directions. Based on these probabilities, entropy of the intra and the WZ modes are computed. A comparison based on the entropy values decides a coding mode between intra coding and WZ coding without relying on any user-specified thresholds or modeling parameters. Experimental results show its superior rate-distortion performance of improvements of PSNR up to 2 dB against a conventional Wyner?Ziv coding without intra mode decision. Furthermore, since the proposed method does not require any thresholds or modeling parameters from users, it is very attractive for real life applications.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.510-518
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• 2016

Ethyl cellulose-g-poly(ethylene glycol) (EP) was synthesized by esterification of carboxylic acid functionalized methoxy polyethylene glycol (MPEG-COOH) with ethyl cellulose (EC) in order to develop a hydrophilic substrate for thin-film composite (TFC) membrane in a forward osmosis (FO) system. A porous EP substrate, fabricated by a non-solvent induced phase separation method, was found to be more hydrophilic than the EC substrate due to the presence of polyethylene glycol (PEG) side chains in the EP. Since the EP substrate exhibits smaller water contact angles and higher porosity, the structural parameter (S) of TFC-EP is smaller than that of TFC-EC, indicating that internal concentration polarization (ICP) within porous substrates can occur less when TFC-EP is used as a membrane. For example, the water flux value of the TFC-EP is 15.7 LMH, whereas the water flux value of the TFC-EC is only 6.6 LMH. Therefore, we strongly believe that the TFC-EP could be a promising candidate with good FO performances.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.519-523
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• 2002

Soluble polysaccharide (SP) from green layer, Enteromorpba prolifera was extracted 3 times with distilled water at 100$^{\circ}C$ for 2 hrs and fractionated with cetylpyridinium chloride (CPC) and ion exchange chromatography (DEAE Separose CL-6B). The SP amounted to $23.7\%$ of the dry seaweed weight and contained $68.8\%$ carbohydrate. It was mainly constituted of rhamnose, glucose, xylose, sulfate and uronic acid and was fractionated with CPC into three (CPC-S, CPC-PS, CPC-PP) tractions. The major acid fraction CPC-PS accounted for $10.2\%$ of the dry algal weight. CPC-PS was further fractionated on DEAE Sepharose CL-6B into Fr-1 ($8.0\%$), Fr-2 ($35.8\%$), Fr-3 ($23.7\%$) fractions. The Fr-3 fraction contained $2.2\%$ protein, $21.4\%$ sulfate, $15.3\%$ uronic acid, and $72.4\%$ polysacchnrides composed of rhamnose, xylose and glucose. The Fr-2 fraction, which was richer in uronic acid ($17.5\%$) and poorer in sulfate ($19.0\%$) and total sugar ($68.8\%$) than the Fr-3, had a sugar composition close to that of Fr-3. The average molecular weights of Fr-2 and Fr-3 were 510,000 and 830,000 daltons, respectively. Fr-3 turned out to be homogeneous by cellulose acetate electrophoresis.

• Journal of Life Science
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• v.23 no.4
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• pp.510-517
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• 2013

This study was performed to evaluate the antiobesity effect of supercritical fluid extracts (SFC) and marc methanol extracts (SFM) from Cinnamomum verum in 3T3-L1 preadipocytes. In inducing the differentiation of 3T3-L1 preadipocytes in the presence of an adipogenic cocktail, iso-butylmethylanthine (IBMX), dexamathasone, and insulin, treatment with fraction residue SFC and SFM. SFC significantly reduced the mRNA expression of the transcription factor peroxisome proliferator-activate-dreceptor-${\gamma}$ ($PPAR{\gamma}$), the sterol regulatory-element-binding protein-1c (SREBP1c), and the CCAAT enhancer-binding-protein ${\alpha}$ ($C/EBP{\alpha}$) in a concentration-dependent manner. Moreover, SFC markedly down-regulated acyl-CoA synthetase-1 (ASC1), fatty acid synthesis (FAS), fatty acid transport-1 (FATP1), fatty acid binding protein 4 (FABP4), and perilipin. These findings suggest that SFC may be a potential therapeutic adjunct for obesity by targeting the differentiation of preadipocytes, as well as their functions.