• Korean Journal of Agricultural Science
• /
• v.45 no.2
• /
• pp.211-218
• /
• 2018

Different packaging methods and storage temperatures were tested to determine the storage stability of beef dry-aged for 21 days based on microbial, physicochemical, and sensory qualities. After completion of the dry aging, the dried surface of beef sirloin was trimmed off, and the beef was packaged using two different methods (oxygen-permeable wrap or vacuum packaging) and stored at different temperatures ($3{\pm}2^{\circ}C$ or $-23{\pm}2^{\circ}C$) for 0, 7, 14, or 21 days. Lipid oxidation and the sensory quality of the dry-aged beef were not affected by the packaging method and storage temperature during storage. No microbial growth was observed over the storage period in the vacuum-packaged dry-aged beef, regardless of the storage temperature. However, dry-aged beef in the oxygen-permeable wrap packaging showed microbial spoilage with 8.82 log CFU / g at day 7 of the refrigerated storage. The vacuum-packaged dry-aged beef showed the lowest values (p < 0.05) in $a^*$ and chroma at days 14 and 21 at $3^{\circ}C$, and days 7 and 14 at $-23^{\circ}C$, respectively. Therefore, it is recommended that dry-aged beef with wrap packaging stored in refrigerated conditions should be consumed as quickly as possible due to microbial growth. For long-term storage, dry-aged beef should be frozen because freezing can extend the color stability up to day 21 of storage without adverse effects on the hygienic or meat quality aspects of dry-aged beef.

• Journal of Environmental Health Sciences
• /
• v.30 no.3
• /
• pp.245-252
• /
• 2004

Two biofilter tests were conducted under different operating conditions. Test # 1 was performed to treat VOCs generated from a paint booth. The second test was performed to treat VOCs generated from chemical manufacturing processes. The volume of biofilter media was 4.3 $m^3$. For the test # 1, the biofilter was operated for 30 days with 99.9% reduction ratio. Range of temperature of each stage of the biofilter media was measured between $34^{\circ}C$ and $73^{\circ}C$. All the temperatures of stages reduced gradually after the initial dramatic increase. For the test # 2, the biofilter experiment was conducted for 14 days. In this case, the biofilter was installed outdoor and the experiment was performed during wintertime. Therefore, temperature management for the biofilter was needed. Seven-centimeter thick fiberglass insulation and $150^{\circ}C$ steam heating were used to overcome the outside freezing cold weather during test # 2. Temperature of stage # 5 was measured the highest and that of stage # 1 was the lowest. More acclimation time and test period was needed to determine the maximum loading rate.

• Economic and Environmental Geology
• /
• v.55 no.6
• /
• pp.727-736
• /
• 2022

Ice wedges are subsurface ice mass structures that formed mainly by freezing precipitation with airborne dust and surrounding soil particles flowed through the active layer into the cracks growing by repeating thermal contractions in the deeper permafrost layer over time. These ice masses characteristically contain high concentrations of solutes and solids. Because of their unique properties and distribution, the possibility of harnessing ice wedges as an alternative archive for reconstructing paleoclimate and paleoenvironment has been recently suggested despite limited studies. It is imperative to preserve the physicochemical properties of the ice wedge (e.g., solute concentration, mineral particles) without any potential alteration to use it as a proxy for reconstructing the paleo-information. Thawing the ice wedge samples is prerequisite for the assessment of their physicochemical properties, during which the paleo-information could be unintentionally altered by any methodological artifact. This study examined the effect of thawing conditions and procedures on the physicochemical properties of solutes and solid particles in ice wedge samples collected from Cyuie, East Siberia. Four different thawing conditions with varying temperatures (4 and 23℃) and oxygen exposures (oxic and anoxic) for the ice wedge sample treatment were examined. Ice wedge samples thawed at 4℃ under anoxic conditions, wherein biological activity and oxidation were kept to a minimum, were set as the standard thawing conditions to which the effects of temperature and oxygen were compared. The results indicate that temperature and oxygen exposure have negligible effects on the physicochemical characteristics of the solid particles. However, the chemical features of the solution (e.g., pH, electric conductivity, alkalinity, and concentration of major cations and trace elements) at 4℃ under oxic conditions were considerably altered, compared to those measured under the standard thawing conditions. This study shows that the thawing condition of ice wedge samples can affect their chemical features and thereby the geochemical information therein for the reconstruction of the paleoclimate and/or paleoenvironment.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.6
• /
• pp.173-179
• /
• 2012

The experiments, which analyze the injury symptoms and diagnose growth conditions utilizing IRVT and analyzing each parts of H. helix L., had been held under a low temperature. Greenhouse and outdoor growing Genus hedera had been prepared and compared with each Genus hedera's peak and bottom leaves' surface temperature under the experimental categories $-6^{\circ}C$ and $-12^{\circ}C$. As results, analyzing the surface thermal property of peak part leaves' of outdoor growing Genus hedera, at experimental categories $-6^{\circ}C$, $-12^{\circ}C$ were ranged from $-2^{\circ}C{\sim}-7^{\circ}C$ and $-2^{\circ}C{\sim}-15^{\circ}C$. On the other hand, the surface thermal property of bottom part leaves at experimental categories $-6^{\circ}C$, $-12^{\circ}C$ were ranged $-2^{\circ}C{\sim}-11^{\circ}C$ and $-1^{\circ}C{\sim}-12^{\circ}C$. It appears that the thermal properties of leaves' surface on $-6^{\circ}C$ peaks and $-12^{\circ}C$ bottoms were more broadband than bottoms and peaks. It means that the peaks were more sensitive than bottoms, as like $-2^{\circ}C{\sim}-15^{\circ}C$, $-1{\sim}-12^{\circ}C$. Moreover, as similar results had seen to leaves surface temperature added to cold wind conditions. How the cold wind damaged the outdoor growing Genus hedera, analyzed the surface thermal property by IRVT data under $0^{\circ}C$, $-2^{\circ}C$, $-4^{\circ}C$ condition, it resulted to $-6.2^{\circ}C$, $-6.8^{\circ}C$, $-7.5^{\circ}C$. It appeared more $3.5{\sim}6.2^{\circ}C$ low temperature than experimental setting point. In addition, each parts thurmal property of peaks and bottoms was not similar, it referred to each parts' sensitivities of low temperature were different on the peak and bottom leaves surface temperature.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.8 no.3
• /
• pp.383-387
• /
• 1998

The vacuum-Bridgman equipment for large size diameter (4 inch more over) crystal growth was organized simply and the $CaF_2$ single crystal which was grown in the conditions of growth rate of 2mm/hr, freezing temperature gradient of $12^{\circ}C$/cm, have analyzed to keep excellent properties. Using Mo thermal reflector of umbrella shape, it could be eliminated the formation of polycrystalline. The preferential growth direction was (111) and the calculated lattice parameter was $5.460 \AA$ by XRD peaks. The secondary phases, also, was not formed by means of powder-XRD analysis. The value of EPD is $1.4{\times}10^4 \textrm{cm}^{-2}$ and the optical quality, which is the transmittance is 91% up in UV region, is suitable for optical components of UV applications.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.12
• /
• pp.1716-1721
• /
• 2006

The present study was conducted to observe the effect of osmolality of glycerolated TEST-yolk glycerol extenders on post-thawing sperm kinematics of ram spermatozoa of the native Malpura breed maintained in a semi-arid tropical environment. Good quality semen obtained from adult rams was pooled, split and diluted to 1,000 million spermatozoa per ml in complete TEST-yolk-glycerol extenders of 900, 1,200, 1,500 and 1,800 mOsm/kg osmolality. Diluted semen samples were loaded in 0.25 ml straws and cooled down to $-125^{\circ}C$ freezing temperature at the rate of $-25^{\circ}C$ per minute under controlled conditions before plunging into liquid nitrogen for storage. The thawing of straws was performed at $50^{\circ}C$ in a water bath for 10 seconds and sperm kinematics of the frozen-thawed spermatozoa were assessed by a computer-assisted sperm analysis technique. Osmolality of diluent had no significant effect on post-thawing % motility, % rapid, % medium and % slow moving frozen-thawed spermatozoa but significantly (p< 0.05) affected the % linearity and % straightness. The post-thawing % motility and % rapid motile spermatozoa were highest in samples extended in diluent of 1,500 mOsm/kg osmolality and lowest in 900 mOsm/kg. The curvilinear velocity of spermatozoa was significantly (p<0.05) higher for samples extended in 1,800 mOsm/kg, compared to those in 900 and 1,200 mOsm/kg, but the effect was not significantly different to those extended in diluent of 1,500 mOsm/kg osmolality. The study indicated that ram spermatozoa could tolerate a wide osmolality range for dilution in the complete TEST-yolk-glycerol extender for their cryosurvival. The highest recovery of motile spermatozoa following thawing was achieved in samples extended in the TEST-yolk-glycerol diluent of 1,500 mOsm/kg osmolality.

• Journal of the Korean Geosynthetics Society
• /
• v.21 no.4
• /
• pp.31-40
• /
• 2022

Recently, the Arctic resource development project, where undeveloped energy resources (oil, natural gas, etc.) are deposited, is actively being promoted for the perspective of diversifying the construction market and developing future energy resources. However, the frozen ground always has problems such as sinking and frost-heaving due to extreme weather. Therefore, it is necessary to analyze the thermal characteristics of the frozen soil to secure the stability of the ground structure. In this study, a series of laboratory tests were performed to evaluated the thermal characteristics of frozen soil samples in the oil sand field in Alberta, Canada. In additon, it was compared with the results of domestic(Gangwond-do) sample performed under the same conditions. As a comparison results of the experiments, it was clarified that the different frozen water content and thermal conductivity characteristics by temperature after completion of freezing could affect the frozen soil behavior.

• Journal of the Korea Society of Computer and Information
• /
• v.29 no.3
• /
• pp.91-98
• /
• 2024

In this paper, we present a particle-grid blending framework based on a geometric approach to efficiently represent opaque ice spheres with air bubbles. The water temperature is diffused through the grid and the air bubbles represented inside the ice through the particles. To solve the problem of previous methods that generate noisy dissolved air fields, we use levelsets to lighten the algorithm, i.e., the number of active particles and the initial amount of dissolved oxygen can be used to efficiently control the termination conditions of heat diffusion. We also extend the previous dissolved air field method, which only computes near air bubbles, to transparent regions to represent realistic ice spheres, and introduce a levelset-based approach to accurately compute the orientation of particles. As a result, the method presented in this paper is about three times faster than the existing methods and shows visually improved visualization of opaque ice spheres, which can be used in the field of representing physical virtual ice forms.

• Geomechanics and Engineering
• /
• v.36 no.2
• /
• pp.145-156
• /
• 2024

The mechanical properties of the concrete-frozen soil interface play a significant role in the stability and service performance of construction projects in cold regions. Current research mainly focuses on the precast concrete-frozen soil interface, with limited consideration for the more realistic cast-in-place concrete-frozen soil interface. The two construction methods result in completely different contact surface morphologies and exhibit significant differences in mechanical properties. Therefore, this study selects silty clay as the research object and conducts direct shear tests on the concrete-frozen soil interface under conditions of initial water content ranging from 12% to 24%, normal stress from 50 kPa to 300 kPa, and freezing temperature of -3℃. The results indicate that (1) both interface shear stress-displacement curves can be divided into three stages: rapid growth of shear stress, softening of shear stress after peak, and residual stability; (2) the peak strength of both interfaces increases initially and then decreases with an increase in water content, while residual strength is relatively less affected by water content; (3) peak strength and residual strength are linearly positively correlated with normal stress, and the strength of ice bonding is less affected by normal stress; (4) the mechanical properties of the cast-in-place concrete-frozen soil interface are significantly better than those of the precast concrete-frozen soil interface. However, when the water content is high, the former's mechanical performance deteriorates much more than the latter, leading to severe strength loss. Therefore, in practical engineering, cast-in-place concrete construction is preferred in cases of higher negative temperatures and lower water content, while precast concrete construction is considered in cases of lower negative temperatures and higher water content. This study provides reference for the construction of frozen soil-structure interface in cold regions and basic data support for improving the stability and service performance of cold region engineering.

• Research in Plant Disease
• /
• v.23 no.3
• /
• pp.283-287
• /
• 2017

The twig blight of mulberry caused by Fusarium lateritium occurs mainly in Buan area, which is the main area of mulberry. The initial symptom on twigs showed dark edge blight and dark orange tiny particles on the spot, and it was withered and died. In the case of mulberry twig blight, the difference in the degree of occurrence between the years is intense, and an average of 2.7% occurred in Buan in 2013, but in 2014, it was difficult to search for the generated fields. In order to find the cause of the difference in the incidence of mulberry twig blight, we investigated and analyzed the weather conditions during cultivation and as a result, the occurrence of the disease increased under the condition that the temperature of the spring was lower and the number of days passing below the winter freezing point increased. In addition, it was analyzed that the occurrence of the next year increases when the rainfall is high and the number of sunshine is low after removing the harvested branches. Therefore, in the event that weather conditions causing twig blight diseases have elapsed, it is necessary to prevent the disease by spraying the registered applied fungicide prophylactically.