• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.460-469
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• 2010

In spite of the global-class aquaculture and fishing technology of our country, the processing technologies are lags behind the other nations relatively. The processed marine products are mainly frozen foods, canned goods, salty food (fermented fish products), fish paste products (boiled fish paste), and we can see that the high-value dehydrated foods by drying are very few. These problems are considered to be caused directly by the lack of drying technologies. This paper is concerned to the experimental results of drying heat transfer characteristics for the green energy type vacuum dryer for the high quality sea foods production.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.268-270
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• 2007

We investigated characteristics of meat quality using by spectroscopic methods in visible region. Characteristics of beef muscle quality was measured by using spectrum analysis. We take the 3 samples of meat, and each sample has 3 measuring point. Also each measured samples has alternate thawing time(the state of frozen meat, thawing 20 minute and thawing 40 minute in the room temperature). As a results of experiments, measured intensity has changed by distributions of Myoglobin in meat muscles. And we can distinction the and characteristics of meat quality by distributions of lean meat and fat.

• Journal of Veterinary Clinics
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• v.4 no.2
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• pp.449-455
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• 1987

Quick freezing of bovine embryos was attempted after they were predehydrated at room temperature. Combined solutions of 2M glycerol or 2M ethylene glycol in the presence of either 0.5 or 1.0M sucrose in phosphated buffered saline+20% calf serum were compared. The quick freezing method in which embryos were directly transferred in liquid nitrogen vapor for 2 minutes at - l70$^{\circ}C$ before being plunged into liquid nitrogen was used. Post-thaw survival rates in 2M glycerol and 2M ethylene glycol were high with 0.5 M (55.6% and 53.3%) versus 1.0M(38.1% and 31.6%) sucrose(P < 0.05). But survival rates with 2M glycerol and 2M ethylene glycol were not significantly different. Transfer thawed embryos frozen with 2M glycerol and 2M ethylene glycol by 0.5M sucrose resulted in birthrates of 40.9% and 40.0%, respectively compared to 26.3% and 27.2%, respectively, for 1.0 M sucrose(p<0.05). This was 56.0% for fresh control.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.330-335
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• 2009

The principal objective of this study was to investigate changes in ice dendrite size during the freezing of tuna, in order to formulate a mathematical model of ice dendrite size. The tuna was frozen via a uni-directional heat transfer. Thermogram analysis allowed us to determine the position of the freezing front versus time, which is referred to as the freezing front rate. The morphology of the ice dendrites was assessed via scanning electron microscopy after freeze-drying, and the retained pore size was measured as ice dendrites. We noted that the mean size of ice dendrites increased with the distance to the cooling plate; however, it decreased with reductions in the cooling rate and the cooling temperature. In addition, shorter durations of the freeze-drying process decreased the freezing front rate, resulting in a larger size of the ice dendrite pores that operate as water vapor sublimation channels. According to our results, we could derive a linear regression as an empirical mathematical model equation between the ice dendrite size and the inverse of the freezing front rate.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.594-599
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• 1988

Methods by which liquid egg could be stored in liquid state at frozen storage temperature$(-15^{\circ}C)$ with selected cryoprotectants and enzyme treatment were investiated, and quality changes in samples during storage were examined. The concentration of cryoprotectants (45% fructose and 55% glucose) to be added to egg yolk and whole egg to store them at $-15^{\circ}C$ in unfrozen state were 45.2% and 70.3%, respectively. Changes in consistency, precipitation of protein and microstructure of egg samples during storage indicated that adding cryoprotectants to liquid egg could effectively inhibit development of gelation during storage at $-15^{\circ}C$. Treating liquid egg with 0.15% papain could inhibit gelation during storage to some extent.

• Journal of Powder Materials
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• v.27 no.3
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• pp.198-202
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• 2020

The effect of sublimable vehicles on the pore structure of Cu fabricated by freeze drying is investigated. The 5 vol% CuO-dispersed slurries with camphene and various camphor-naphthalene compositions are frozen in a Teflon mold at -25℃, followed by sublimation at room temperature. After hydrogen reduction at 300℃ and sintering at 600 ℃, the green bodies of CuO are completely converted to Cu with various pore structures. The sintered samples prepared using CuO/camphene slurries show large pores that are aligned parallel to the sublimable vehicle growth direction. In addition, a dense microstructure is observed in the bottom section of the specimen where the solidification heat was released, owing to the difference in the solidification behavior of the camphene crystals. The porous Cu shows different pore structures, such as dendritic, rod-like, and plate shaped, depending on the composition of the camphornaphthalene system. The change in pore structure is explained by the crystal growth behavior of primary camphor and eutectic and primary naphthalene.

• Journal of Powder Materials
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• v.27 no.3
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• pp.193-197
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• 2020

Porous Cu-14 wt% Co with aligned pores is produced by a freeze drying and sintering process. Unidirectional freezing of camphene slurry with CuO-Co₃O₄ powders is conducted, and pores in the frozen specimens are generated by sublimation of the camphene crystals. The dried bodies are hydrogen-reduced at 500℃ and sintered at 800℃ for 1 h. The reduction behavior of the CuO-Co₃O₄ powder mixture is analyzed using a temperature-programmed reduction method in an Ar-10% H₂ atmosphere. The sintered bodies show large and aligned parallel pores in the camphene growth direction. In addition, small pores are distributed around the internal walls of the large pores. The size and fraction of the pores decrease as the amount of solid powder added to the slurry increases. The change in pore characteristics according to the amount of the mixed powder is interpreted to be due to the rearrangement and accumulation behavior of the solid particles in the freezing process of the slurry.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.163-172
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• 2013

In this study, the cooling of rocket exhaust plume by sprayed water inside plume were investigated as varying of sprayed water mass, location, and method using computational fluid analysis. For Analyze rocket exhaust plume, a single species unreacted analysis model based on the chemically frozen analysis was used and the discrete particle model which was a kind of Euler-Lagrangian analysis model was used for simulate sprayed water inside plume. It was confirmed that the temperature of plume was reduced without cooling when water mass was two times of plume mass through analysis results.

• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.39-42
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• 2002

In the current study, characteristics of the laser-induced plasma were investigated in a gas filled chamber or in a gas jet by using a relatively low intensity laser $(I\;\leq\;5\;\times\;10^{12}\;W/cm^2)$. Temporal evolutions of the produced plasma were measured using the shadow visualization and the shock wave propagation as well as the electron density profiles in the plasma channel was measured using the Mach-Zehnder interferometry. Experimental results such as the structure of the produced plasma, shock propagation speed $(V_s)$, electron density profiles $(n_e)$, and the electron temperature $(T_e)$ are discussed in this study. Since the diagnostic laser pulse occurs over short time intervals compared to the hydrodynamic time scales of expanding plasma or a gas jet, all the transient motion occurring during the measurement is assumed to be essentially frozen. Therefore, temporally well-resolved quantitative measurements were possible in this study.

• Journal of Mechanical Science and Technology
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• v.17 no.8
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• pp.1164-1170
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• 2003

The objectives of this work here focus on the differences in responses to multiple cyclic tests of different sections along the length of the same tendon. Tendon specimens were obtained from the hindlimbs of canines and frozen to -70$^{\circ}C$. After thawing, specimens were mounted in the immersion bath at room temperature (22$^{\circ}C$) , preloaded to 0.13 N and then subjected to 3% or 4% of the initial length at a strain rate of 5%/sec. It was found that different sections of the same long tendons had different resistances to deformation. In general, the bone end sections were stiffer and carried greater loads for a given strain than the muscle end sections, and the mid-portions were the least stiff and carried the smallest loads for a given strain. The results of this study offer new information about the mechanical responses of collagenous tissues. We know more about their responses to multiple cyclic extensions and how their responses are different from the positions along the length of the tendon specimen. The nature and causes of these differences in the stiffness are not fully known. However, it is clear that differences in the mechanical response of tendons and other connective tissues are significant to musculoskeletal performance.