• Composites Research
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• v.24 no.6
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• pp.18-24
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• 2011

The effect of surface treatments with the atmospheric pressure flame plasma (APFP) and epoxy silane (ES) is experimentally investigated to yield the best mechanical properties of silica ($V_f=40%$) reinforced elastomeric composites. The tensile strength of the composites is increased significantly with decrease the mean diameter. When the diameter is $2.2{\mu}m$, that of the composite is increased about 1.4 times compared to the matrix (2.52 MPa). Also, the tensile strength of silica reinforced composites with APFP and ES treated is increased 8.8~13.3%, 9.9~12.5%, respectively. When the diameter is $26.6{\mu}m$, the tensile modulus of the composite is increased about 2 times compared to the matrix (0.88MPa), and the tensile modulus of silica reinforced composites with APFP and ES treated is increased 15.6~22.8%, 21.1~5.8%, respectively. Conventional silane coupling agent treatment have a few disadvantages because of using organic solvents. However APFP treatment is a fast, economic and eco-friendly method to improve the mechanical properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1622-1627
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• 2007

This study was undertaken to evaluate the effects of chlorine dioxide on reducing E. coli O157:H7 and L. monocytogenes on broccoli served in foodservice institutions. Broccoli samples inoculated with $10^6$ CFU/mL of E. coli O157:H7 and L. monocytogenes were treated with chlorine dioxide. Treatments with 5, 10, and 20 ppm for 1, 5, and 10 min were not sufficient in controlling E. coli O157:H7 on broccoli. L. monocytogenes were effectively reduced by $2.19{\sim}2.48log\;CFU/g\;and\;3.31{\sim}3.87log\;CFU/g$ with 10 and 20 ppm chlorine dioxide for 1, 5, and 10 min treatment, respectively, compared with the control. E. coli O157:H7 and L. monocytogenes population were significantly negatively correlated with concentration and treatment time of chlorine dioxide. These results show that the use of chlorine dioxide was effective in sanitizing L. monocytogenes on broccoli and the level of concentration was more associated with populations of E. coli O157:H7 and L. monocytogenes than treatment time of chlorine dioxide on broccoli.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.3
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• pp.315-324
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• 2012

This paper presents a numerical investigation of the deflagration-to-detonation transition (DDT) of flame acceleration by a shock wave filled with an ethylene/air mixture as the combustible gas, considering geometrical changes by using obstacles and bent tubes. The model used consists of the reactive compressible Navier-Stokes equations and the ghost fluid method (GFM) for complex boundary treatment. Simulations with a variety of bent tubes with obstacles show the generation of hot spots through flame and strong shock-wave interactions, and restrained or accelerated flame propagation due to geometrical effects. In addition, the simulation results show that the DDT occurs with a nearly constant chemical heat-release rate of 20 MJ/($g{\bullet}s$) in our numerical setup. Furthermore, the DDT triggering time can be delayed by the absence of unreacted material together with insufficient pressures and temperatures induced by different flame shapes, although hot spots are formed in the same positions.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.240-246
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• 2012

This study evaluated the efficacy of strong acidic electrolyzed water (SAcEW), low alkaline electrolyzed water (LAlEW) and aqueous chlorine dioxide (ACD) for reducing pathogenic bacteria($Escherichia$ $coli$, $Bacillus$ $cereus$, $Salmonella$ Typhimurium, $Stapylococcus$ $aureus$) on Chinese cabbage. Artificially inoculated Chinese cabbage was immersed for 1, 5 and 10 min with TW, NaClO, EW and ACD. Generally, leaves showed more effective reduction than stems. Regarding the inhibitory effect, ACD treatment showed the highest effects rather than other treatments. When Chinese cabbage was immersed for 3 min in sterilized water, it was reduced to a minimum of 1.33 log CFU/g at LAlEW and a maximum of 4.70 log CFU/g at ACD. Compared to NaClO, ACD and LAlEW which showed a reduction of 3.2 log CFU/g ($Sal.$ Typhimurium) and 2.7 log CFU/g($B.$ $cereus$), respectively. Furthermore, the others had similar inhibitory effects compared to NaClO.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.761-771
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• 2014

The study was conducted to evaluate effects of weed managements after false seedbed on the weed control and growth of spring and fall cabbages (Brassica oleracea L.) in an organic upland in 2013. Weed managements included rake, flame, PE mulch, and none treatment. The weed occurrence was not effectively controlled by rake treatment but controlled by flame treatment in spring and fall cultivation. PE mulch plots had 30% of tip-burn in spring cultivation. Weed managements after false seedbed were similar fresh weight, leaf number, and cabbage yield to the conventional PE mulch. Head of cabbage was the lowest on the none treatment. Fall cultivation reduced the weed density and increased yield of cabbage compared to those of spring in all treatment plots. In conclusion, rake or flame treatment after false seedbed markedly decreased weed occurrence, which was expected to use for management of environmentally-friendly vegetation as a substitute of PE mulch.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.77-84
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• 2005

The considerations for reminder life of transmission line is gradually higher. It is requisite for investigation of ACSR life to test tensile load of ACSR as a fundamental data. It is vary important to analysis correlations between results of tensile load testing and elapsed years. Estimation of ACSR life can be obtained by statistics processing using mechanical experimental results. It is a general method to use regression analysis as a statistics processing technique. In this paper, we did experiment on tensile strength of ACSR by using a new and due to flame for artificial fire, and gathering due to a flame. The limit of life estimation is decided by basic line using twenty percentage reduction of rate tensile strength. This basic line is like to results of Canada Ontario Hydro-research. There are $480[mm^2]$ ACSR which are experimented on this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.402-407
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• 2012

The effects of a combined treatment of aqueous chlorine dioxide ($ClO_2$) and ultraviolet-C (UV-C) irradiation on microbial growth in celery and cherries were investigated. Celery and cherry samples were treated with 50 ppm $ClO_2$, UV-C at dose of 10 kJ/$m^2$, and a combination of $ClO_2$ and UV-C. The changes in the counts of Escherichia coli O157:H7 inoculated in the celery and cherries as well as those of total aerobic bacteria, yeast and molds in the celery and cherries were investigated after each treatment. After the combined treatment of aqueous $ClO_2$ and UV-C irradiation, the populations of E. coli O157:H7 in the inoculated celery and cherries were reduced by 2.8 and 3.0 log CFU/g, respectively, compared to those of the control. For the un-inoculated celery and cherries, the populations of total aerobic bacteria were reduced by 2.9 and 1.8 log CFU/g, respectively, compared to the control. In addition, the populations of yeast and molds were decreased by 1.8 and 1.2 log CFU/g, respectively. These results suggest that the combined treatment of 50 ppm $ClO_2$ and UV-C at a dose of 10 kJ/$m^2$ would be an effective technology for decontamination and improving the microbiological safety in celery and cherries during chilled storage.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.628-631
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• 2017

An experimental study of the combustion characteristics according to the equivalence ratio of hydrocarbon fuel/air premixture excited by ultrasonic standing wave are presented. The image of the propagating flame was acquired using a high-speed camera, and the combustion characteristics of each fuel were closely observed through image processing. it was conformed that ultrasonic standing wave has been found to stimulate the combustion reaction in the stoichiometric ratio.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.4
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• pp.1-8
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• 2016

An experimental study was performed for the combustion-field visualization of the burner which burns the liquid hydrocarbon fuel atomized by an ultrasonic oscillator. Configurations of the flame and combustion-field were caught by both high-speed camera and thermo-graphic camera, and those images were analyzed in detail through a post-processing. As a result, the combustion-field grew and reaction-temperature rose due to the strengthening of combustion reaction with the increasing flow-rate of carrier-gas. In addition, a phenomenon of flame flickering was discussed through the comparative analysis of the variational behaviors between the visible flame and IR (Infrared) flame-field.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.43-49
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• 2016

An experimental study was performed to investigate the combustion characteristics of the liquid hydrocarbon fuel atomized by an ultrasonic oscillator. Configuration of the flame was caught by the DSLR camera, and images were analyzed in detail through a post-processing. Temperature of the flame zone was measured using thermocouple. It is resulted that the flame area is proportional to the mass flow rate of carrier gas as well as the voltage applied to the ultrasonic oscillator. Temperature of the flame zone is measured and analyzed according to variation in the operating condition of the burner, too.