• Food Engineering Progress
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• v.22 no.4
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• pp.328-336
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• 2018

The aim of this study was to investigate the effect of pretreatments on quality of frozen peach. Pretreatments including steam blanching, water blanching, high pressure, and osmotic dehydration were applied to two varieties (Daeokgye and Hwangdo). Pretreated peaches were frozen and thawed at $-20^{\circ}C$ and $5^{\circ}C$, respectively. Steam blanching and osmotic dehydration with ascorbic acid reduced ${\Delta}E$ values without change of pH and acidity. Osmotic dehydration with sucrose decreased drip loss and increased brix. Freezing/thawing resulted in an increase of maximum force, while maximum force decreased with increasing time of steam and water blanching. Furthermore, osmotic dehydration with calcium chloride increased maximum force. High pressure decreased maximum force of Daeokgye and increased that of Hwangdo compared with non-treatment. Total polyphenol content, DPPH radical scavenging activity, and ABTS radical scavenging activity were improved by pretreatment including steam blanching, blanching, and osmotic dehydration with ascorbic acid.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.47-52
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• 2008

Deicer has been generally used for prevention of a road freezing in winter, and the usage amount is increasing every year. However, deicer may induce the decrease of bond strength, surface scaling, and environmental pollution. In this study, the field test was performed to investigate the deterioration of concrete road structures used for 17 years. And, the corrosion resistance characteristics were compared for the existing deicer and eco-friendly deicer. According to the field test results, the penetration depth of limit chloride amount was about 40mm, and the average concentration of chloride was $3.45kg/m^3$ at the surface of structures. On the contrary, the carbonation depth was slight. The penetration depth of eco-friendly deicer was less than the existing deicer, and the corrosion resistance of eco-friendly deicer was higher.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.161-169
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• 2014

We present the results of an experimental physical weathering study that focuses on fresh and slightly weathered gneiss samples from the Wonju area of Korea. The study investigated changes in the physico-mechanical properties of these samples during accelerated laboratory-based weathering, including analyses of microfracture formation. The deteriorated samples used in the study were subjected to 100-150 freeze-thaw cycles, with index properties and microfracture geometries measured between each cycle. Each complete freeze-thaw cycle lasted 24 hours, and consisted of 2 hours of saturation in a vacuum chamber, 8 hours of freezing at $-21^{\circ}C{\pm}1^{\circ}C$, and 14 hours of thawing at room temperature. Specific gravity and seismic velocity values were negatively correlated with the number of freeze-thaw cycles, whereas absorption values tended to increase. The amount of deterioration of the rock samples was dependent on the degree of weathering of the rock prior to the start of the analysis. Absorption, specific gravity, and seismic velocity values can be used to infer the amount of physical weathering experienced by a gneiss in the study area. The sizes and density of microfracture in the rock specimens varied with the number of freeze-thaw cycles. We found that box fractal dimensions can be used to quantify the formation and propagation of microfracture in the samples. In addition, these box fractal dimensions can be used as a weathering index for the mid-and long-term prediction of rock weathering. The present results indicate that accelerated-weathering analysis can provide a detailed overview of the weathering characteristics of deteriorated rocks.

• Journal of Powder Materials
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• v.19 no.6
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• pp.446-450
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• 2012

In order to fabricate the porous Mo with controlled pore characteristics, unique processing by using $MoO_3$ powder as the source and camphene as the sublimable material is introduced. Camphene-based 15 vol% $MoO_3$ slurries, prepared by milling at $50^{\circ}C$ with a small amount of dispersant, were frozen at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $750^{\circ}C$, and sintered at $1000-1100^{\circ}C$ for 1 h. After heat treatment in hydrogen atmosphere, $MoO_3$ powders were completely converted to metallic W without any reaction phases. The sintered samples showed large pores with the size of about $150{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal wall of large pores and near bottom part of specimen had relatively small pores due to the difference in the camphene growth rate during freezing process. The size of small pores was decreased with increase in sintering temperature, while that of large pores was unchanged. The results are strongly suggested that the porous metal with required pore characteristics can be successfully fabricated by freeze-drying process using metal oxide powders.

• Journal of the Korean association of regional geographers
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• v.9 no.4
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• pp.534-545
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• 2003

The main purpose of this paper is to describe the granitic regolith and frost creep phenomena in Daegwanryung area in order to demonstrate the relationship of the weathered materials and the surrounding surface, in order to point out that the characteristics of this particular complex of granitic regolith most closely resemble those of soil frost creep phenomena formed elsewhere under periglacial conditions. For this study, the writer has clarified their structure and its associated milieux, with a group of methods and techniques, field survey, micro-morphological analysis, granulometry of weathered materials etc. Such facies of granitic regolith in situ with silty heterometric materials and micas are prone to be deformed by cryo-suction as well as deep freezing. It was probably formed by cryogenic activity, or frost creep in the periglacial climate of a very cold and humid condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.125-132
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• 2012

Urea-SCR system, which converts nitrogen oxides to nitrogen and water in the presence of a reducing agent, usually AdBlue urea solution, is known as one of the powerful NOx reduction systems for mobile as well as stationary applications. For its consistent and reliable operation in mobile applications, such various problems as transient injection, ammonia slip, and freezing in cold weather have to be resolved. In this work, therefore, numerical study on three-dimensional unsteady heating problems were analyzed to understand the melting and heat transfer characteristics such as urea liquid volume fraction, temperature profiles and generated natural convection behavior in urea solution by using the commercial software Fluent 6.3. After validating by comparing numerical and experimental data with pure gallium melting phenomena, numerical experiment for urea melting is conducted with three different coolant heating models named CH1, 2, and 3, respectively. Finally, it can be found that the CH3 model, in which more coolant is concentrated on the lower part of the urea tank, has relatively better melting capability than others in terms of urea quantity of $1{\ell}$ for start-up schedule.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1095-1104
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• 2014

This paper presents the results of experimental work on both strength characteristics and durability of concrete or mortar having 50% ground granulate blastfurnace slag(GBS) with different fineness levels (4,450, 6,000 and $8,000cm^2/g$). Compressive and split tensile strength test results indicated that the concrete with a higher fineness level of GBS exhibited a better strength development due to the acceleration of latent hydraulic property at the later curing stage compared with ordinary portland cement concrete. Meanwhile, it was found that a higher fineness level of GBS showed some negative effects on the resistance against freezing-thawing action. However, incorporation of GBS to concrete, irrespective of fineness levels, significantly enhanced the chloride ions penetration resistance. The resistance against sulfate attack of mortar with GBS was greatly dependent on the attacking sources from sulfate environments.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.23-35
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• 2004

The weathering characteristics of periodically submerged sedimentary rocks in the Sayeon dam, Ulsan was examined by field work, electron probe micro-analysis, X-ray diffraction, and X-ray fluorescence spectrometry. Analysis of fracture zone and exfoliation showed the submerged sedimentary rocks have undergone severe mechanical weathering. Mechanical weathering in the water-rock interface accelerated chemical weathering, such as dissolution and alteration of the most of minerals except for quartz in the weathering zone. The dissolution of carbonates specially calcite, is remarkable creating the cavities, whereas formation of minerals including clay minerals is not active. The sedimentary rocks have been periodically submerged for a certain period of time, and have repeated freezing and thawing. This mechanical weathering favored infiltration, which accelerated mineral dissolution. The high content of easily soluble carbonate of the sedimentary rocks is likely the major cause of intense chemical weathering. The dissolved elements within the infiltrated water interrupted the occurrence of clay and weathering minerals, and expend fractures by infiltrated water accelerated weathering process.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.13 no.2
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• pp.149-158
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• 2002

This research was conducted to investigate changes in quality characteristics of gamma-irradiated porks during storage at different temperature and periods. In The proximate composition of pork was not significantly changed by irradiation dose and storage period. The SDS electrophoresis patterns were not significantly different between nonirradiated and irradiated samples. All samples stored in at 5$^{\circ}C$ showed a prominent breakdown of molecular weights ranging from 97,000 to 116,000 Daltons after 8 weeks' storage. In heme pigment(myoglobin) content, metmyoglobin content of chicken stored at 5$^{\circ}C$ was not affected by gamma irradiation but slightly increased with the increase in storage period. All samples stored at -2$0^{\circ}C$ were not different in heme pigment content between nonirradiated and irradiated samples and slightly decreased as the freezing storage period increased. About textural property, hardness of all samples appears to be increased slightly by gamma irradiation. However, the extent of increase was so little that it could be ignored.

• Journal of Acupuncture Research
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• v.23 no.6
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• pp.153-164
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• 2006

Introduction : The Aim of the Study Is to Investigate the Characteristics of Yangdorak m the Patients with Idiopathic Parkinson's Disease. Methods : Subjects Were Voluntarily Recruited by Newspapers And Internet. All the Subjects Were Confirmed as Idiopathic Parkinson's Disease by a Neurologist. The Patient's Symptoms Were Assessed by Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn-Yahr (H-Y) Stage, Schwab & England Activity of Daily Living And Freezing of Gait Questionnaire(FOGQ). Sasang Constitution Was Differentiated by QSCCII. Yangdorak Was Measured after 15 minutes' Bed Rest Results : The Results Were as Follows; 1. The Average Value of Yangdorak m 50 Patients with Parkinson's Disease Was $39.01{\pm}17.97$. 2. The Mean Values of Fl, F2, F3, F4, F5 and F6 were under 40. 3. The Number of Pyesaek Was Significantly Increased According to H-Y Stage. 4. The Yangdorak Value Had No Significant Correlation between UPDRS, H-Y Stage and Duration. 5. There Was No Significant Difference in the Value of Yangdorak among Sasang Constitutions. Conclusion : This Study Suggests that Yangdorak Can Be Used as a Assistant Tool to Investigate the Patients of Parkinson's Disease. Further Study on the Yangdorak And Parkinson's Disease Is Recommended.