• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.457-463
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• 2013

The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of dressing. The hazard analysis examined the main materials, industrial water, microbial evaluation, and airborne microorganisms of each working area, as well as the pathogenic microbial contamination risk. The survey was conducted at SJ Company in Jincheon (Chungchengbuk-do), Korea for 30 days from April 1, 2012 to April 30, 2012. The results showed that raw material microorganisms had a total plate count in industrial water below $3.00{\times}10$ CFU/mL in working room I, working room II, the packing room, washing water, and the inspection room for five times in each place. During dressing production (including heat treatment and mixing), general bacteria were detected at an average of $3{\times}10$ CFU/mL, but yeast, mold, and pathogenic bacteria were not detected. Airborne microbiological evaluation (for total plate count, yeast, and mold) found levels below the legal limit at each working area. While workers were positive for microbes in total plate counts, coliform and Staphylococcus aureus were not detected. In conclusion, standards for hygienic management should be established to prevent and decrease hazards, such as general bacteria and pathogenic microorganisms (for example, E. coli, B. cereus, Listeria spp, Salmonella spp, Staph. aureus, Clostridium perfringens, yeast, and mold), and to found critical limits for microorganisms with an HACCP system.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.3
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• pp.139-145
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• 2011

Objectives: This investigation is purposed to evaluate the airborne asbestos concentrations in the public buildings having asbestos containing materials(ACMs) in Seoul. Methods: The Seoul Metropolitan Government carried out an asbestos survey to the city-owned public buildings to identify the level of risk exposure, classified into low, moderate and high risk. To evaluate the airborne concentration of asbestos, 11 sampling sites in ten buildings based on the survey were selected. The air samples from the eleven sites were analyzed by Phase Contrast Microscopy(PCM) and Transmission Electron Microscopy (TEM), and compared the analytical results from the both. Results: 1. The airborne fiber concentrations by PCM were less than the detection limit($7f/mm^2$) in 9(82%) out of 11 sampling sites. The highest concentration was 0.0043 f/cc, but it was below the guideline value for indoor air quality(0.01 f/cc), proposed by the Ministry of Environment, Korea. 2. In two sampling sites, having moderate risk level, the chrysotile was identified and showed it's concentrations of 0.0102 s/cc and 0.0058 s/cc, less than $5{\mu}m$ lengths. 3. The ACMs identified in the two sampling sites were a packing material(65% of chrysotile) in mechanical area and a thermal system insulation(5% of chrysotile) in a boiler room. Having more possibility of asbestos emission in the mechanical area, it would be required to set up and carry out the asbestos management plan. Conclusions: Based on the result of this study, the airborne asbestos concentrations in the public buildings with ACMs were generally lower than the guideline value for indoor air quality. There are widespread concerns about the possible health risk resulting from the presence of airborne asbestos fibers in the public buildings. Most of the previous studies about airborne asbestos analysis in Korea were performed based on PCM method that asbestos and non-asbestos fibers are counted together. In the public and commercial buildings, having ACMs, it is suggested that the asbestos be analyzed by TEM method to identify asbestos due to concerns about asbestos exposure to workers and unspecified people.

• Food Science and Preservation
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• v.15 no.6
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• pp.847-851
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• 2008

The handling and processing of agricultural products in Korea is done manually. Small plastic boxes, nets, and corrugated cardboard boxes are used as containers during harvesting, sorting and other product handling operations. However, these practices are labor-intensive, time-consuming, require various kinds of packing materials, and are expensive because of high operating costs. To overcome these problems, the use of pallet bins with pre-cooling and storage features for handling and processing bulk farm products was investigated. The airflow resistances through bulk potato, onion and mandarin stocks were measured, and the pallet bins and a pressure pre-cooling device were manufactured. The opening ratio, bed depth and airflow rate through bulk potato, onion and mandarin in the pallet bin were defined with regression equations. The cooling rates of bulk potato, onion and mandarin were 0.8C/h ($21.7{\rightarrow}0C$, 14.5 h), 0.4C/h ($15.4{\rightarrow}.0C$, 32.2 h) and 0.7C/h ($13.7{\rightarrow}C$, 18.8 h), respectively, with the pressure pre-cooling system. Temperature deviances for storage of bulk potato, onion and mandarin were 0.12C, 0.12C and 0.17C, respectively.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.1
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• pp.1-7
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• 2017

The recognition rate of RFID system is made a big difference by the selection of tag type and performance of reader, packing materials and the attachment location of tag and the recognition of angle according to the above factors. Water content is the most effective factor among the various elements that affected to the recognition of RFID as the center. Therefore, the purpose of this study was to measure the RFID recognition rate per water content, the distance recognition rate of RFID tag, the RFID tag and the recognition rate by contact area. In analysis of recognition rate according to water content, 100% of recognition was possible when food product contained 0~25% moisture. However, when water content was over than 30%, recognition rate was declined less than 95%. The recognition rate between RFID tag according to water content was higher when distance was over than 0.3 cm. In the recognition rate about the contact area of RFID tag according to water content, the recognition rate was declined when the contact area becomes wider.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.45-52
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• 2010

Two different imide oligomers(6FDA-ODA/APA and 6FDA-MDA/MA) having crosslinkable end groups were prepared by using a solution imidization method and their properties were investigated. Also, semi-interpenetrating polymer networks(semi-IPN) were prepared using the blends of imide oligomers with polyetherimide $Ultem^{(R)}$, which is used in dual-ovenable packaging materials. The characteristic properties of semi-IPN films were interpreted by using TGA, Thin Film Diffusion Analyzer, and WAXD. Molecular weights of imide oligomers were successfully controlled utilizing 2-aminophenylacetylene(APA) and maleic anhydride(MA) as an endcapping agent. Exotherm reactions by crosslinking appeared and the amount of exthotherm heat was linearly increased as the content of imide oligomers was increased. For semi-IPNs of $Ultem^{(R)}$ and imide oligomers, 5% and 10% weight loss temperatures increased as the contents of imide oligomers were increased. Diffusion coefficient and water uptake of semi-IPNs decreased as the content of imide oligomers was increased, which might be resulted from hydrophobic fluorine group and high packing density. It was concluded that relatively low thermal stability and hydrolytic stability of polyetherimide $Ultem^{(R)}$ were improved by incorporating new developed imide oligomers.

• Journal of Information Display
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• v.11 no.1
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• pp.8-11
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• 2010

In this study, a new thin films passivation technique using Zn with high electronegativity and $MgF_2$, a fluorine material with better optical transmittance than the sealing film materials that have thus far been reported was proposed. Targets with various ratios of $MgF_2$ to Zn (5:5, 4:6 and 3:7) were fabricated to control the amount of Zn in the passivation films. The Mg-Zn-F films were deposited onto the substrates and Zn was located in the gap between the lattices of $MgF_2$ without chemical metathesis in the Mg-Zn-F films. The thickness and optical transmittance of the deposited passivation films were approximately 200 nm and 80%, respectively. It was confirmed via electron dispersive spectroscopy (EDS) analysis that the Zn content of the film that was sputtered using a 4:6 ratio target was 9.84 wt%. The Zn contents of the films made from the 5:5 and 3:7 ratio targets were 2.07 and 5.01 wt%, respectively. The water vapor transmission rate (WVTR) was determined to be $38^{\circ}C$, RH 90-100%. The WVTR of the Mg-Zn-F film that was deposited with a 4:6 ratio target nearly reached the limit of the equipment, $1\times10^{-3}\;gm^2{\cdot}day$. As the Zn portion increased, the packing density also increased, and it was found that the passivation films effectively prevented the permeation by either oxygen or water vapor. To measure the characteristics of gas barrier, the film was applied to the emitting device to evaluate their lifetime. The lifetime of the applied device with passivation was increased to 25 times that of the PLED device, which was non-passivated.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.35-43
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• 2011

Permeable Reactive Barriers (PRB) method is an economical method that does not require any other methods to be operated once it is installed as it controls of groundwater flow in the barrier, which is inserted a reactive material on the way of pollutant. The major dominant element of PRB is a reactive material in the reactive wall, and such factors as purification efficiency and used time based on the chemical and physical features in between the reactant and pollutant. High purification efficiency can be expected when a rational design that is synthetically considered in features of packing density, operation period, and adsorption reactant of pollutant. A column test was conducted for an application test using CFW as its adsorption reactant in order to remove copper($Cu^{2+}$) in the PRB system. The CFW was used for the reactant and selected inflow speed, density and thickness of PRB as its necessary factors for design of PRB. As a result of the experiment, the removal efficiency decreased as operating time of PRB increased and the efficiency linearly increased upon the length. Therefore, it is confirmed that the thickness of reactive materials in PRB system can be designed using the proposed formula considering purification time and density of CFW.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.282-282
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• 2017

The many factors such as sugar content, moisture, type of bacteria which predominate, buffering capacity, packing and sealing are known to be associated with silage fermentation quality. Among the sugar content are particularly important, because effective silage ensiling relies on the fermentation of sugar content to lactic acid by lactic acid bacteria. Sugar content is also known to affect the protein utilization of rumen. This study was conducted to observe the effect of water soluble carbohydrates on fermentation characteristics and in vitro digestibility of whole crop wheat silage. This experiment was used standard cultivars (Cheongwoo, Hordeum balgare L) and solid breeding line of whole crop wheat. The materials harvested at the 30 after heading day and chopped for making silage, and using this silage carried out in vitro digestibility for 6, 12, 24 and 48 hours. For the feed value, crude protein, NDF, ADF contents showed slightly higher than the before ensiling and TDN contents were slightly lower compared to the before ensiling, but did not show the significantly different. For the sugar contents, fructose and glucose contents were decreased in the after ensiling compared to the before ensiling, there were more reduced at the containing high sugar content wheat. The pH value was lower at containing high sugar content wheat. lactic acid content was significantly higher at the containing high sugar content wheat. Therefore, there was profitable to the production of high quality wheat silage at the higher the sugar content. In in vitro digestibility test, containing high sugar content HW34line showed significantly higher dry matter digestibility at 6 and 12 hours of incubation and amount of NH3-N lower other line in all incubation time. Therefore, there was profitable to the production of high quality wheat silage at the higher the sugar content.

• Food Science and Preservation
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• v.6 no.3
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• pp.270-275
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• 1999

During the storage period of chives(Allium Tubersum fouler) at low temperature(4-5$^{\circ}C$), weight loss in chives by the packages of LDPE, p.p and HDPE film was decreased less than 1%, however that of chives unpacked was remarkably increased as time went by. Soluble solids of unpacked chives was decreased from 6.0 to 4.6 $^{\circ}$Brix after 2 weeks storage and that of LDPE film sealed was lessened to 4.9-5.9 $^{\circ}$Brix, the treatment of deaeration showed a tendency to decrease a lot to 4.5-4.7 $^{\circ}$Brix. The vitamin C content of chives unpacked was 37.1mg% at before storage, but after one week decreased very much to 15.2mg%, and that in chives packed by the different methods was visibly lessened after 2 weeks storage. the Vitamin C content in chives processed by deaeration sealing method was lessened compared to that at chives processed by sealing only. In the bag of chives packed by HDPE film had low CO$_2$ and C$_2$H$_4$ concentration and the gas concentration in the bag of chives processed by P.P. film was increased as storage period went by. Conclusively the freshness of chives packaged by LDPE and HDPE film maintained for 3 weeks, at P.P film for 2 weeks, but the marketability of chives unpacked was degraded in 3-4 days.

• Membrane Journal
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• v.22 no.5
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• pp.359-368
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• 2012

For hybrid water treatment of high turbidity water, we used the hybrid module that was composed of photocatalyst packing between tubular membrane outside and module inside. Photocatalyst was PP (polypropylene) bead coated with $TiO_2$ powder by CVD (chemical vapor deposition) process. Water back-flushing of 10 sec was performed per every period of 10 min to minimize membrane fouling for modified solution was prepared with humic acid and kaolin. Resistance of membrane fouling ($R_f$) decreased as humic acid concentration changed from 10 mg/L to 2 mg/L, and finally the highest total permeate volume ($V_T$) could be obtained at 2 mg/L, which was the same with the previous results. Then, treatment efficiencies of turbidity and humic acid were above 98.9% and 88.7%, respectively. As results of treatment portions of UF, UF + $TiO_2$, and UF + $TiO_2$ + UV processes, turbidity was treated little by photocatalyst adsorption, and photo-oxidation. However, treatment portions of humic acid by adsorption and photo-oxidation were 2.5% and 12.3%, respectively. Compared with the previous results, treatment portions of humic acid by adsorption and photo-oxidation were different depending on membrane material and pore size. As simplified the process, the membrane fouling resistance after 180 minutes' operation ($R_{f,180}$) increased and the final permeate flux decreased a little.