• Title/Summary/Keyword: Freezing point

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STUDIES ON THE FREEZING OF YELLOW SEA BREAM (옥돔의 동결에 관한 연구 2. 동결에 의한 옥돔조직의 변화)

  • SONG Dae-Jin;KANG Yeung-Joo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.12 no.3
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    • pp.131-136
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    • 1979
  • Histological changes of yellow sea bream, Branchiostegus japonicus japonicus, were observed under microscope during freezing storage for 6 months at $65^{\circ}C$ and $-35^{\circ}C$, and the results were compared with the muscle structure of fresh muscle. The freezing storage of yellow sea bream at $-^{\circ}C$ showed more changes in muscle structure than that stored at $-35^{\circ}C$. In the view point of the changes of the muscle structure, the yellow sea bream can be stored up to 1 month at $65^{\circ}C$ and 3 months at $-35^{\circ}C$. The freezing of yellow sea bream at $-5^{\circ}C$ showed higher extracellular freezing than that at $-35^{\circ}C$.

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A Geomorphological Study on the Distribution Areas of Freezing during Summer Season in Korea (한국의 하계 동결현상 분포지에 관한 지형학적 연구)

  • Jeon, Young-Gweon
    • Journal of the Korean association of regional geographers
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    • v.7 no.1
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    • pp.97-106
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    • 2001
  • There are a few interesting areas which show freezing during summer season in Korea, three of them are especially important. They are located at Milyang(Gyungnam province), Uisung and Chungsong(Gyungbook province). They are named Eoleumgol(ice-valley) or Binghyul(ice-cave). The purpose of this study is to clarify geomorphological and geological characteristics about the distribution areas of freezing during summer season in Korea in relation to previous works, which have been studied in hydrological or micro-climatological viewpoints. The main results are summarized as follows. 1) The main geomorphological and geological characteristics in the distribution areas of freezing during summer season (1) Thick debris accumulated slope within deep valley (2) North facing slope (3) The component debris of volcanic rock such as andesite or rhyolite 2) The ice-cave as a system that give rise to freezing phenomenon in summer season is closely related to talus slope. The ice-cave has thick accumulated debris and lots of vacant spaces within the rock deposits, some of vacant spaces are very big and connected with underground water system. 3) A partly freezing within underground water system is required freezing phenomenon in summer season. Judging from this point of view, two ideas are suggested; one is the evaporation theory, another is that the frozen condition in winter remains untill late summer.

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Characteristics of Elastic Waves in Sand-Silt Mixtures due to Freezing (동결에 따른 모래-실트 혼합토의 탄성파 특성)

  • Park, Junghee;Hong, Seungseo;Kim, Youngseok;Lee, Jongsub
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.4
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    • pp.27-36
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    • 2012
  • The water in surface of the earth is frozen under freezing point. The freezing phenomenon, which causes the volume change of soils, affects on the behavior of soils and causes the significant damage on the geotechnical structures. The purpose of this study is to investigate the characteristics of elastic waves in sand-silt mixtures using small size freezing cells, which reflect the frozen ground condition due to temperature change. Experiments are carried out in a nylon cell designed to freeze soils from top to bottom. Bender elements and piezo disk elements are used as the shear and compressional wave transducers. Three pairs of bender elements and piezo disk elements are placed on three locations along the depth. The specimen, which is prepared by mixing sand and silt, is frozen in the refrigerator. The temperature of soils changes from $20^{\circ}C$ to $-10^{\circ}C$. The velocities, resonant frequencies and amplitudes of the shear and compressional waves are continuously measured. Experimental results show that the shear and compressional wave velocities and resonant frequencies increase dramatically near the freezing points. The amplitudes of shear and compressional waves show the different tendency. The dominant factors that affect on the shear wave velocity change from the effective stress to the ice bonding due to freezing. This study provides basic information about the characteristics of elastic waves due to the soil freezing.

Density Measurement Technique and Prediction Model of Fruit Juices under Freezing Point (빙점이하에서 과일쥬스의 밀도측정방법 및 예측모델)

  • Bae, Dong Ho;Choi, Yong Hee
    • Current Research on Agriculture and Life Sciences
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    • v.6
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    • pp.163-169
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    • 1988
  • This study was conducted to predict the density changes according to concentration and temperature changes under freezing point. This information is needed for the design of freezing equipment and for the efficient utilization of refrigerating system. Orange juice, Apple juice, Grape juice and Sucrose solution were used for the measurement of density in this study at the temperature range from $-5^{\circ}C$ to $-40^{\circ}C$ and at the concentration range from 10 to 40%. The unfrozen water fraction of samples was determined by Heldman's method. The density values were determined by measuring the weight of a frozen solution at each temperature with a known volume. Solutions were placed in the thick-walled aluminum tubes. When the solution was frozen the excess ice was removed with a razor until the surface of the ice was flush with the top of the aluminum tube. The tube and ice were weighted immediately. Knowing the volume, tare weight, and final weight, the density could be determined. With this procedure, the data of density and unfrozen water fraction for fruit juices and sucrose solution were collected. The density prediction models of fruit juices and sucrose solution under freezing point were established by the optimization computer program with measured experimental data.

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Study on the melting characteristics of the Fe-C eutectic temperature fixed-point (Fe-C 공정 온도 고정점의 용융 특성에 대한 연구)

  • Kim, Yong-Gyoo;Yang, In-Seok;Gam, Kee-Sool
    • Journal of Sensor Science and Technology
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    • v.15 no.4
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    • pp.257-262
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    • 2006
  • A Fe-C eutectic cell for thermocouple calibration was manufactured and tested to investigate its phase transition characteristics in the thermocouple thermometry. It was observed that the freezing plateaus were strongly affected by the freeze-inducing temperature $T_{f}$. In case of the melting process, the melting plateau was influenced by the previous thermal history. As $T_{f}$. in the previous freezing was lower, the melting plateau became lower with a temperature dependence as small as $-0.0015^{\circ}C/^{\circ}C$. Therefore, it was found that the freeze-inducing temperature should be fixed to obtain a reproducible phase transition temperature in the melting. After fixing $T_{f}$, the melting process was examined and it was found that long and flat melting plateau was obtained within a reproducibility of about ${\pm}0.01^{\circ}C$. Based on the observed results, it was recommended that Fe-C eutectic temperature be best realized for the melting process with a melt-inducing temperature of $+3^{\circ}C$ above the expected liquidus temperature after freezing at $-5^{\circ}C$ below the solidus temperature.

A Real Time Measurement of Ice Concentration of Ice Slurry in Pipe (배관내 흐르는 아이스슬러리의 실시간 얼음분율 측정)

  • Jung, Hae-Won;Peck, Jong-Hyeon;Kim, Yong-Chan;Kang, Chae-Dong;Hong, Hi-Ki
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.8
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    • pp.599-606
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    • 2007
  • An experimental study was performed to measure a ice concentration of ice slurry flowing in a pipe in a real time. In the present paper, we suggested a measuring method by a refractive index and compared it to other methods by a freezing point and a density. To measure the refractive index of the solution, ice particles in the ice slurry should be completely removed and a hydro-cyclone was introduced instead of a mesh. The measuring method through the refractive index coincided with the density method using the real-time solution density within ${\pm}5%$ error range, having the error range less than the other two methods. In the other hand, the measuring method through the density has a good resolution, but the result using the initial density of the solution was different more than 10% error from that using the real-time density. And it has an error range 1.5 times greater than the method through the refractive index.

Effect of Freeze Concentration Process on the Physicochemical Properties of Milk

  • Park, Sung-Hee;Kim, Soo-Hun;Hong, Guen-Pyo;Kwak, Hae-Soo;Min, Sang-Gi
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2005.05a
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    • pp.297-302
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    • 2005
  • Physicochemical properties were compared between freeze concentrated and vacuum evaporated milk through colour, brix, viscosity, freezing point and pH measurement. Brix and viscosity in each concentrated milk significantly increased due to solute concentration(p<0.05), and there was not much difference between freeze concentrated and evaporative one. Brix results were numerically modeled with the logarithmic regression: Y=-33.460+18.4513 ${\cdot}$ ln(X), $R^2=0.9798$ and this model was fairly fit to predict the solute concentration in the middle of freeze concentration process. Freezing point significantly decreased according to concentration increment(p<0.05) and there was not the significant difference between freeze concentrated and evaporated one. Whereas, in colour and pH value, there were some differences between freeze concentrated and evaporative milk. Vacuum evaporated milk expressed higher discoloration comparing to freeze concentrated one. In pH values, evaporated milk showed the significantly decreased results comparing to freeze concentrated sample, whereas the pH value of freeze concentrated sample expressed the similar value to the reference milk.

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Measurement and Verification of Unfrozen Water Retention Curve of Frozen Sandy Soil Based on Pore Water Salinity (간극수 염분농도에 따른 동결 사질토의 부동수분곡선 산정 및 검증 연구)

  • Kim, Hee-Won;Go, Gyu-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.39 no.11
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    • pp.53-62
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    • 2023
  • The characteristics of unfrozen water content in frozen soils significantly impact the thermal, hydraulic, and mechanical behavior of the ground. A thorough analysis of the unfrozen water content characteristics of the target subsoil material is crucial for evaluating the stability of frozen ground. This study conducted indoor experiments to measure the freezing point and unfrozen water content of sandy soil while considering pore water salinity. Utilizing the experimental data, we introduced a novel empirical model to conveniently estimate the unfrozen water retention curve. Furthermore, the validity of the unfrozen water retention curve was assessed by comparing the experimental data with the results of a simulation model that utilized the proposed empirical model as input data.

The biomechanical and biological effect of supercooling on cortical bone allograft

  • MuYoung Kim ;Hun-Young Yoon
    • Journal of Veterinary Science
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    • v.24 no.6
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    • pp.79.1-79.16
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    • 2023
  • Background: The need for a storage method capable of preserving the intrinsic properties of bones without using toxic substances has always been raised. Supercooling is a relatively recently introduced preservation method that meets this need. Supercooling refers to the phenomenon of liquid in which the temperature drops below its freezing point without solidifying or crystallizing. Objectives: The purpose of this study was to identify the preservation efficiency and applicability of the supercooling technique as a cortical bone allograft storage modality. Methods: The biomechanical effects of various storage methods, including deep freezing, cryopreservation, lyophilization, glycerol preservation, and supercooling, were evaluated with the three-point banding test, axial compression test, and electron microscopy. Additionally, cortical bone allografts were applied to the radial bone defect in New Zealand White rabbits to determine the biological effects. The degree of bone union was assessed with postoperative clinical signs, radiography, micro-computed tomography, and biomechanical analysis. Results: The biomechanical properties of cortical bone grafts preserved using glycerol and supercooling method were found to be comparable to those of normal bone while also significantly stronger than deep-frozen, cryopreserved, and lyophilized bone grafts. Preclinical research performed in rabbit radial defect models revealed that supercooled and glycerol-preserved bone allografts exhibited significantly better bone union than other groups. Conclusions: Considering the biomechanical and biological superiority, the supercooling technique could be one of the optimal preservation methods for cortical bone allografts. This study will form the basis for a novel application of supercooling as a bone material preservation technique.