• Journal of the Korean Society of Tobacco Science
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• v.8 no.1
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• pp.23-31
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• 1986

The water content, physical property and sensory of cigarette brands lave been studied from the view point of the individual and inner packages. It was found that the cigarettes had absorbed the moisture from alto more than 56% of a relative humidity (RH) and lost it under RH, 56%. The critical moisture contents for the optimum quality of cigarette maintenance were 7.7% through 14.595 in the range of equilibrium relative humidity (ERH) 52.2%-63.5%. The ERH at the initial moisture content of 12.1% showed 58.8% When cigarettes were storaged in 9095 of RH and 4$0^{\circ}C$, the shelf life of the Inner package was respectively shown 18.8 days In cellophane, 33.3 days In PET(25u), 69.8 days in OPP and 73.5 days in OPP film coated with PVDC. As shown above, the longest life time was found in the OPP film coated with PVDC. In the individual packages, the shelf life of packaging materials used above was significantly short in the same conditions as of the inner packages. Each shelf life of the individual packages was same In order comparing with that of the inner Packages.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.47-52
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• 1999

Comparative effects of phosphine fumigation and gamma irradiation were evaluated on the qualities of white ginseng prepacked in a commercial laminated film in terms of water absorption, Hunter color parameters(L, a, b) and organoleptic properties(overall color/appearance, flavor) during 6 months of storage at ambient(20oC, 70% RH) and accelerated(40oC, 90% RH) conditions. Moisture content of packed white ginseng(initial 8.44%) linearly increased with storage period, thereby reaching to about 10% (r=0.9966) in ambient and more than 15%(r=0.9886) in accelerated conditions, respectively, at the 6th month of storage. The storage at severe conditions resulted in remarkable changes in Hunter's color values, decrease in whiteness(L) and increase in redness(a) and yellowness(b), while both treatments, phosphine and irradiation less than 5kGy, did not cause any significant changes in color parameters. Phosphine fumigation was shown detrimental to overall flavor of white ginseng(p<0.01), however or ganoleptic qualities of stored samples were effectively maintained by irradiation less than 5kGy(p< 0.05). As the index on the guality of white ginseng stored at severe conditions its organoleptic quality was highly correlated with moisture content(r= 0.9777) and Hunter color values(over 0.9), suggesting the critical values of 15.5% moisture and 72.56, 7.15, 21.45 in Hunter's L, a, b values, respectively.

• Macromolecular Research
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• v.14 no.5
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• pp.573-578
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• 2006

Three different, polymer-platinum conjugates (hydrogels, microparticles, and nanoparticles) were synthesized by complexation of cis-dichlorodiammineplatinum(II) (cisplatin) with partially succinylated glycol chitbsan (PSGC). Succinic anhydride was used as a linker to introduce cisplatin to glycol chitosan (GC). Succinylation of GC was investigated systematically as a function of the molar ratio of succinic anhydride to glucosamine, the methanol content in the reaction media, and the reaction temperature. By controlling the reaction conditions, water-soluble, partially water-soluble, and hydrogel-forming PSGCs were synthesized, and then conjugated with cisplatin. The complexation of cisplatin with water-soluble PSGC via a ligand exchange reaction of platinum from chloride to the carboxylates induced the formation of nano-sized aggregates in aqueous media. The hydrodynamic diameters of PSGC/cisplatin complex nano-aggregates, as determined by light scattering, were 180-300 nm and the critical aggregation concentrations (CACs), as determined by a fluorescence technique using pyrene as a probe, were $20-30{\mu}g/mL$. The conjugation of cisplatin with partially water-soluble PSGC, i.e., borderline between water-soluble and water-insoluble PSGC, produced micro-sized particles $<500{\mu}m$. Cisplatin-complexed PSGC hydrogels were prepared from water-insoluble PSGCs. All of the cisplatin-incorporated, polymer matrices released platinum in a sustained manner without any significant initial burst, suggesting that they may all be useful as slow release systems for cisplatin. The release rate of platinum increased with the morphology changes from hydrogel through microparticle to nanoparticle systems.

• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.75-83
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• 2002

This paper is to investigate the mechanical characteristics of light-weighted soils (LWS) consisting of expanded polystyrene(EPS), dredged clays and cement by using both uniaxial and triaxial compression tests. The mechanical characteristics of the compressive strength of LWS are analysed with varying initial water contents of dredged clays, EPS ratio, cement ratio, and curing stress. In the triaxial compression state, it is found that the compressive strength of LWS containing EPS is independent on the effective confined stress. As the EPS ratio decreases($A_E$<2%) and cement ratio increases($A_c$>2%), the behavior characteristics of triaxial compressive strength-strain relationship is similar to that of cemented soil which decreases rapidly in compressive strength after ultimate compressive strength. For the applications of LWS to ground improvements which require the compressive strength of up to 200kPa, the optimized EPS ratio and initial water content of dredged clay are estimated to be 3~4% and 165~175%, respectively. Also, the ultimate compressive strength under both triaxial test and uniaxial compression states are almost constant for a cement ratio of up to 2% and then critical cement ratio of this LWS shall be 2%.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.164-170
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• 1999

Cracking of rice caused by moisture migration during storage under different relative humidity conditions was investigated for the establishment of safe storage condition of rice. Rice was cracked when a large difference in equilibrium relative humidity $({\Delta}ERH)$ between the rice and the environment was present. External and internal cracks were generated as the results of moisture desorption and adsorption, respectively. The external cracks by moisture desorption generated in all directions and shaped irregularly, while the internal cracks by moisture adsorption did in radial direction and showed a typical shape. The cracking trend could be analyzed by the Weibull function, and the cracking constant increased with ${\Delta}ERH$. The frequency of cracked rice increased linearly with In $({\Delta}ERH)$. The critical crack-inducing ${\Delta}ERH$ was $11.3{\sim}16.4%$ during desorption and $10.8{\sim}17.1%$ during adsorption. A diagram for the safe storage of rice was developed with respect to the initial moisture content and the water activity of rice.

• Geomechanics and Engineering
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• v.20 no.6
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• pp.537-546
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• 2020

Oil and natural gas reserves have been recognised abundantly in clayey rich rock formations in deep costal reservoirs. It is necessary to understand the sedimentary history of those reservoir rocks to well explore these natural resources. This work designs a group of laboratory experiments to mimic the physical process of the sedimentary clay-rich rock formation. It presents characterisation results of the physical properties of the artificial clayey rocks synthesized from illite clay, quartz sand and brine water by high-pressure consolidation tests. Special focus is given on the effects of illite clay content and high-stress consolidation on the physical properties. Multi-step loaded consolidation experiments were carried out with stress up to 35 MPa on mixtures constituting of the illite clay, quartz sand and brine water with five initial illite clay contents (w=85%, 70%, 55%, 40% and 25%). Compressibility and void ratio were characterised throughout the physical compaction process of the mixtures constituting of five illite clay contents and their water permeability was measured as well. Results show that the applied stress induces a great reduction of clayey rock void ratio. Illite clay contents has a significant influence on the compressibility, void ratio and the permeability of the physically synthesized clayey rocks. There is a critical illite clay content w=70% that induces the minimum void ratio in the physically synthesised clayey rocks. The SEM study indicates, in the high-pressure synthesised clayey rocks with high illite clay contents, the illite clay minerals are located in layers and serve as the material matrix, and the quartz minerals fill in the inter-mineral pores or are embedded in the illite clay matrix. The arrangements of the minerals in microscale originate the structural anisotropy of the high-pressure synthesised clayey rock. The test findings can give an intuitive physical understanding of the deep-buried clayey rock basins in energy reservoirs.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.946-956
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• 2020

To identify the effect of sodium-alternative curing salts on the quality properties of salami through the ripening process, four salami treatments were prepared with different curing salts, T1 (-control, NaCl 1.9%), T2 (+control, NaCl 1.9%+NaNO₂ 0.01%), T3 (KCl 1.9%+NaNO₂ 0.01%), and T4 (MgCl₂ 1.9%+NaNO₂ 0.01%), under 40 days ripening conditions. Sodium-alternative salts (T3 or T4) showed characteristically different quality traits compared with T2. Especially, T3 had lower pH, water activity, volatile basic nitrogen, and lipid oxidation after 20 days of ripening period, compare with T2 or T4 (p<0.05). Sodium nitrite had critical impact on increased a* values, and T3 showed higher a* values compared with T2 or T4 (p<0.05). Sodium nitrite reduced initial growth of coliforms but sodium-alternative salts did not affect microbial growth patterns. T2-T4 containing sodium nitrite had higher content of umami nucleotide flavor compounds compared with T1, regardless of the chlorine salt species. The combined use of sodium-alternative curing salts and minimal sodium nitrite was found to be an applicable strategy on development of low sodium salami without a trade-off of the product quality.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.47-56
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• 2008

The objective of this research is to evaluate the optimum recycling methods for the sewage sludge cakes at different microwave power-settings and for different periods of time. The dehydrated sewage sludge cakes used in this study was obtained from N wastewater treatment plan in the P City. The beginning drying processes were carried out in a microwave oven with 2,450 MHz frequency and power ranges of 1kW to 4 kW. The continuous conveyer drying system was also operated with 2,450 MHz frequency and power setting, ranging from of 1 kW to 6 kW. Initial moisture content of the sewage cake is 78~80%, and the moisture content decreased rapidly up to 0.2~2(wt%) within short periods due to breaking the cell walls. This study is also conducted to evaluate the characteristics of sewage sludge cakes with respect to important physical parameters effect on the thermal kinetics for evaporation water in the sludge which are operation times, moisture contents, drying rates, input amounts, flow rates and calorific values. It takes 60 minutes and 120 minutes to reach the critical moisture contents with power setting of 4 kW for 3kg/min and 6kg/min of the flow rates respectively. It takes 120 minutes and 110 minutes to reach the critical moisture contents with flow rates of 2.5 cm/min and sludge input of 6kg/min for the power settings of 4 kW and 6 kW respectively. The most effective value of the power for drying the sludge is 4 kW. Operation with 6kg/min and 4kW on 2cm of the sludge thickness can be effectively and inexpensively to reach the critical moisture contents, when you compare 2cm of the sludge thickness with 1cm and 3cm of the sludge thickness.

• Clean Technology
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• v.12 no.3
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• pp.128-137
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• 2006

The volume change of an ionic liquid and the phase separation behavior of room temperature ionic liquid(RTIL)/organic compound mixture in supercritical carbon dioxide were measured in a high pressure view cell. 1-Butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][$BF_4$]) was used as ionic liquid(IL). and methanol and dimethyl carbonate were used as organic compound. For a fixed amount of [bmim][$PF_6$] the lower critical endpoint (LCEP) pressure, where the liquid phase is split, decreased as increasing the amount of organic compound. The LCEP pressure became higher as the water content of ionic liquid was higher. However, for water contents above a certain value, no LCEP was formed. LCEP appeared 1.0 MPa higher for a mixture with [bmim][$BF_4$] than with [bmim][$PF_6$]. There was almost no difference in the K-point pressures for different types of ionic liquid and for different amounts of organic liquid. When the concentration of ionic liquid([bmim][$PF_6$]) (IL/(IL+MeOH)) in the initial liquid mixture was larger than 5.9 mol% at the LCEP of the mixture, the volume of $L_1$ because larger than the volume of $L_2$. When it was smaller, however, the volume became smaller, too. The volume change of ionic liquid in the presence of carbon dioxide decreased as increasing the temperature, while it increased as increasing the pressure. For temperatures between 313.15 to 343.15K at 300 bar, it was about 123~125 % of the original volume.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.353-360
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• 1984

As an effort to expand the utilization of mackerel which has been thought disadvantageous to processors due to the defects in bloody dark color of meat, high content of lipid, and low stability of protein, and to develope a new type of product, so called, preservative fish meat paste, the processing method was studied in which dielectric heating was applied by means of cooking, pasteurization, dehydration, and control of water activity. The principle of this method is based on that dielectric heating can initiate a rapid dispersion or displacement of moisture in the meat tissue so that the level of water acivity can be controlled by dehydration with hot air meanwhile the product is cooked, pasteurized, and texturized. And the product is finally heated with electric heaters and vacuum sealed to stabilize water activity and storage stability. In present paper, a formula for preparing the fish meat-stach paste, the conditions of dielectric heating and dehydration, shape and size of the product, and other parameters were tested to optimize the process operation. A formula of the fish meat-starch paste to provide proper textural properties and water activity was $10\%$ starch, $1.5\%$ salt, $3\%$ soybean, $0.6\%$ MSG, $2\%$ sucrose, and $3\%$ sorbitol against the weight of fish meat. A proper shape and size of the product to avoid foaming and case hardening during heating was sliced disc of 8 cm $diameter{\times}0.8$ cm thickness or $10{\times}10$ cm square plate with 1.0 cm thickness. The disc shape was recommended because it resulted more uniform heating, minimum foaming and case hardening. And it was also advantageous that disc was simply provided when the fish meat disc was stuffed in the same, solidified in boiling water for 2 to 3 minutes, and sliced. Condition of dielectric heating was critical to decide the levels of sterility, water activity, and textural property of the product. The temperature at the center of the meat disc slices was raised up to $95^{\circ}C$ in 1.5 minutes so that continuous exposure to microwave caused expanded tissue and hardening ending up with a higher water content. Heating for 5 to 6 minutes was adequate to yield the final water activity of 0.86 to 0.83(35 to $40\%$ moisture). It is important, however, that heating had to be done periodically, for instance, in the manner of 2.0, 1.5, 1.5, and 1.0 minute to give enough time to displace or evaporate moisture from the meat tissue. The product was dehydrated for 2 to 3 minutes by hot air of $60^{\circ}C$, 3 to 5m/sec and finally exposed to electric heaters for 5 to 6 minutes until the surface was roasted deep brown. These conditions of heating and dehydration resulted in a complete reduction of total plate count from an initial count of $5.3{\times}10^6/g$ to less than $3{\times}10^2/g$. General composition of the product was $40.1\%$ moisture, $20.8\%$ protein, $17.4\%$ lipid, $16.2\%$ carbohydrate, and $5.5\%$ ash. Textural properties revealed folding test AA, hardness 42, cohesiveness 0.53, toughness 4.6, and elasticity 0.8.