• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.35 no.1
• /
• pp.19-26
• /
• 2003

In recent years, numerous studies have been carried out to find out the possible substitution of PE-coated paperboards used in packaging of watery or oily foods. Accordingly, this study was carried out to obtain the basic data for producing higher functional coating agents for pulp mold by evaluating various kinds of mixed coating agents. At that time, two kinds of synthetic coating agents(AKD, PYA) and three kinds of natural coating agent(CMC, corn starch, oxidized starch) were used for making the mixed coating agents respectively. Physical properties of coated paperboards were tested. Conclusions obtained from this study were as follows. Based on concentrations, the proper mixture ratios were 10:90(AKD:CMC), 10:90(AKD:corn starch), 10:90(AKD:oxidized starch), 40:60(PVA:CMC), 20:80(PVA:corn starch) and 20:80(PYA:oxidized starch). The mixed coating agent of PYA:corn starch(20:80) was the most efficient coating agent. Consequently, water and oil resistance were improved even with much addition of natural coating agents. We consider that they can be suitable for the packaging used in the storage of higher moisture vegetables and other food, and also can be suitable for oily fried food.

• Microbiology and Biotechnology Letters
• /
• v.20 no.5
• /
• pp.505-510
• /
• 1992

An endo-$\beta$-1,4-glucanase gene of Clostridium thermocellum was cloned in Escherichia coli and was considered as a novel gene by comparison with the restriction patterns of the C. thermocellum cellulase genes so far reported. The endoglucanase from recombinant E. coli was purified by column chromatography after heat treatment. The purified enzyme was a monomer having molecular weight of 40,000. The enzyme hydrolyzed CMC to glucose and cello-oligosaccharides at :naximum activities at pH 5.0 and $65^{\circ}C$. One of the endproducts, glucose, showed no inhibitory effect on the enzyme activity, while the other endproduct, cellobiose, inhibited slightly. The values of $K_{m}$ and $V_{max}$ of the enzyme for CMC were 0.39% (w/v) and 268 Ulmg protein, respectively.

• Journal of the Korean Society of Combustion
• /
• v.13 no.1
• /
• pp.31-43
• /
• 2008

Oxy-fuel flame has a significantly different structure from that of air-fuel flame because of its high temperature. This study is aimed to find out the difference of the oxy-fuel flame structure in order to understand reaction mechanism closely, which is crucial to design real-scale oxy-fuel combustion system. By examining pictures of counterflow flame and LIF images, we found that oxy-fuel flame had two-zone structure: fuel decomposition region and distributed CO oxidation region. In the oxy-fuel flame, OH radical was distributed intensely through the whole flame due to its higher flame temperature than crossover temperature. For showing those features of the oxy-fuel flame, 1 MW scale IFRF oxy-natural gas burner was simulated by conditional moment closure(CMC) model. Calculation results were compared with experimental data, and showed agreements in trend. In the simulated distributions of fuel decomposition/CO oxidation rates, CO oxidation region was also separated from fuel decomposition zone considerably, which showed the two-zone structure in the oxy-fuel flame.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.31 no.4
• /
• pp.69-75
• /
• 1999

This study was performed to investigated the application of mixed resins for corrugated container board. The corrugated container board yields a sandwich structure in which a linerboard material is glued to a corrugated medium . Now, manufacturing corrugated container boards don't provide sufficient strength, and result in box failure during shipping . Therefore improvement of box strength is necessary . In this study, we intend to improve box strength by improving corrugated medium strength with mixed resins and to find the optimum treatment condition of this resins. First, we tried to mixed resins as Starch+CMC, Starch_Irea, CMC+Urea, Second, investigated to applicability of this resins for corrugated medium , and the third, measured tensile index, burst index, and edgewise compression index on liner, medium paper, and single faced corrugated container board. In this test results, we obtained that the improvement ratios of tensile index in liner and medium paper were approximately 80-185%, 60-118% , respectively. The respecting improvement ratios of edgewise compression index of single faced corrugated container board was approximately 91-124%, relatively. In addition, we concluded that optimum condition in mixing ratio was 1 :3 with CMC + Urea and the ap[plication amounts was 9% on materials. Fro manufacture of corrugated container board, optimum condition in mixing ratio was 1 : 3 with 5% CMC +Urea , because of considering to improvement of strength on cost.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.1 s.244
• /
• pp.67-73
• /
• 2006

This investigation deals with the spin-up flows in a circular container of aspect ratio, 2.0. Shear front is generated in the transient spin-up process and propagating from the side wall to the central axis in a rotating container. Propagation of the shear front to the axis in a rotating container means the region acquires an angular momentum transfer from the solid walls. Propagating speed of the shear front depends on the apparent viscosity of polymer solution. Two kinds of polymer solutions are considered as a working fluid: one is CMC and the other is CTAB solution. CMC solution has larger apparent viscosity than that of water, and CTAB shows varying apparent viscosities depending on the applied shear rates. Transient and spatial variations of the apparent viscosities of the present polymer solutions (CTAB and CMC) cause different speeds of the propagating shear front. In practice, CMC solution that has larger values of apparent viscosity than that of water always shows rapid approach to the steady state in comparison of the behavior of the flows with water. However, for the CTAB solution, the speed of the propagating of the shear front changes with the local magnitude of its apparent viscosity. Consequently, the prediction of Wedemeyer's model quantitatively agrees with the present experimental results.

• Journal of the Korean Applied Science and Technology
• /
• v.29 no.1
• /
• pp.47-53
• /
• 2012

This study is concerned with coemulsifier which is better emulsifiable properties than emulsifier itselves' use only. It's compound was synthesized by esterification of propylene glycol and succinic acid. The structure of them was comfirmed with FT-IR and $^1H$-NMR. Surface active properties with surface tension, cmc, emulsing power were tested respectively at given conditions. Their surface tensions in the aqueous solution was decreased to 33-35 dyne/cm and their cmc was evaluated by surface tension method. And it's emulsifying power was excellent in jojoba oil. As results, the synthesized dipropylene glycol succinate is expected to apply as O/W coemulsifier.

• International Journal of Oral Biology
• /
• v.43 no.2
• /
• pp.83-91
• /
• 2018

Nonthermal atmospheric plasma has been studied for its many biomedical effects, such as tooth bleaching, wound healing, and coagulation. In this study, the effects of dentinal tubules occlusion were investigated using fluoride-carboxymethyl cellulose (F-CMC) gel, nano-sized hydroxyapatite (n-HA), and nonthermal atmospheric plasma. Human dentin specimens were divided to 5 groups (group C, HA, HAF, HAP, and HAFP). Group HA was treated with n-HA, group HAF was treated with n-HA after a F-CMC gel application, group HAP was treated with n-HA after a plasma treatment and group HAFP was treated with n-HA after a plasma and F-CMC gel treatment. The occlusion of dentinal tubules was investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS), which shows Ca/P ratio. In the EDS results, a higher Ca/P ratio was shown in the groups including n-HA than in the control group. The specimens of group HAP and HAFP had a higher Ca/P ratio in retentivity. In the SEM results, there was not a significant difference in the amount of times applied. Therefore, this study suggests F-CMC gel and n-HA treatment using nonthermal atmospheric plasma will be a new treatment method for decreasing hypersensitivity.

• Korean Journal of Veterinary Research
• /
• v.56 no.3
• /
• pp.155-160
• /
• 2016

This study was conducted to evaluate three different mixed formulations of sodium hyaluronate (SH) and carboxymethyl cellulose (CMC) using a low-humidity air flow-induced rat dry eye model and determine the most suitable mixture. The total thickness of the cornea, corneal epithelial thickness, corneal stroma thickness, damaged corneal epithelium percentage region, thickness of the bulbar conjunctiva epithelium, number of goblet cells, goblet cell occupation percentage region, and damaged bulbar conjunctiva epithelium percentage region were measured by histomorphological evaluation. After 5 h exposure to drying airflow, the thickness of the cornea and conjunctiva was decreased with desquamation of the corneal and conjunctiva epithelium. However, these dry eye symptoms were markedly inhibited by treatment with the reference and test formulations. More favorable effects on decreased thickness were detected in response to the CMC than the SH. However, SH had a greater protective effect against corneal and conjunctiva epithelial damage. The application of a mixture of 0.1% SH and 0.2% CMC showed more favorable effects on the corneal and conjunctival damage and the stabilization of the ocular surface than SH or CMC alone.

• Journal of the Korean Chemical Society
• /
• v.18 no.5
• /
• pp.354-357
• /
• 1974

The critical micelle concentration(CMC) of sucrose monostearate is determined between 20 and $40^{\circ}C$, and the effect caused by the addition of sucrose distearate on the CMC is also studied. It is found that, when both of monoester and diester are dissolved, the curve of surface tension of the solution versus the concentration shows a discontinuity at about 40 dyne $cm^{-1}$ of the surface tension. The discontinuity is interpreted as the associate formed between monoester and diester changes its surface orientation at this region.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.1
• /
• pp.85-92
• /
• 2000

This study was carried out to storage of Pleurotus ostreatus packed in various trays made by different matrials-expanded polystyrene (EPS), rice straw pulp(RP), and RP trays coated with starch, carboxyl methyl cellulose (CMC), polyacrylamide (PAM), alkylketen dimer (AKD), rosin size (RS) and polyethylene glycol (PEG) at 8~1$0^{\circ}C$ and 70~80% relative hymidity for 6 days. At 6 days storage, weight increase of RP and CMC tray was lower (p<0.05) than those of others and the weight of oyster mushroom packed in RP, CMC and AKD tray decreased lower(p<0.05) than those of others. Carbon dioxide contents in trays were increased from 0.5% to 5.5%~8.6% within 1 day storage. Oxygen contents in trays were sharply decreased from 20% to 0.8%~8.2% within 1 day storage. Lightness of oyster mushroom increased all trays. Off flavor appeared stronly in oyster mushroom packed in EPS, AKD and PEG during storage, but was not detected in mushroom packed in starch and CMC until 4 days storage.