• Food Science of Animal Resources
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• v.34 no.6
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• pp.757-762
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• 2014

The object of this study was to investigate the difference in physical and sensory properties of various premium ice creams. The physical properties of the various ice creams were compared by manufacturing brand. The water contents of the samples differed, with BR having the highest value at 60.5%, followed by NT and CS at 57.8% and 56.9%, respectively. The higher the water content, the lower Brix and milk fat contents in all samples. The density of the samples showed almost similar values in all samples (p>0.05). The viscosity of each ice cream had no effect on the water content in any of the brands. Before melting of the ice cream, the total color difference was dependent on the lightness, especially in the vanilla ice cream, owing to the reflection of light on the surface of the ice crystals. The CS product melted the fastest. In the sensory test, CS obtained a significantly higher sweetness intensity score but a lower score for color intensity, probably due to the smaller difference in total color, by which consumers might consider the color of CS as less intense. From this study, the cold chain system for ice cream distribution might be important to decide the physical properties although the concentration of milk fat is key factor in premium ice cream.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.11
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• pp.1028-1034
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• 2004

Recently, the ice storage system using ice slurry has been used increasingly since it has been introduced where the rapid cooling load change is required. Because it overcomes a decrease of the melting performance and an increase of the thermal resistance on the ice layer in static ice thermal storage system. This study is performed to understand the effects of transporting ice slurry through horizontal, vertical and inclined tubes ($30^{\circ},\;45^{\circ}$). It used propylene glycol-water solution and ice particles (diameter of about 2 mm) in this experiment. The experiments were carried out under various conditions, with concentration of water solution ranging from 0 to $20wt\%$, and velocity of water solution at the entry ranging from 1.5 to 2.5 m/s. The results were as follows: Regarding the angle of inclined tube, the highest pressure loss was measured for vertical tube and the pressure loss for $45^{\circ},\;30^{\circ}$, horizontal straight tubes were lower successively. The lowest pressure loss in these tubes was measured at velocity of $2.0{\sim}2.5m/s$ and concentration of $10wt\%$. The outlet IPF was likewise stable in these ranges.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.1115-1117
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• 2020

환경 문제는 사람들이 직접적으로 보지 못하면 쉽게 이해하기 어렵다. 그리고 오랜 시간 동안 아주 조금씩 환경 파괴가 발생하는 경우가 많기 때문에, 실질적으로 환경 문제를 체감하는 것이 쉽지 않다. 본 연구에서는 몰입형 가상현실 시스템을 이용해서 기후변화의 원인인 지구온난화로 인해 북극과 남극의 바다 빙하가 녹고 있는 문제를 체험할 수 있도록 Melting Sea Ice 를 개발하였다. 사용자들은 몰입형 가상현실 장치를 착용하고 시간의 흐름에 따라 남극 북극 빙하가 녹은 모습과 해빙에 따른 생태 환경의 변화를 직접 돌아다니면서 관찰할 수 있다. 본 연구에서는 Melting Sea Ice 가상현실 콘텐츠를 통하여 기후 변화로 인한 환경 파괴 문제를 직관적으로 인식시키고 환경 문제를 해결하고자 하는 동기부여를 목적으로 두고 있다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.6
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• pp.434-440
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• 2007

One of the cold start problems of a FCV is the freezing of the water in the water tank when a FCV is not in operation and the surrounding temperature drops below $0^{\circ}C$. The ice in the tank should be melted as quickly as possible for a satisfactory operation of fuel cell vehicles. In this study, the melting process for the constant heat fluxes of the plate heaters was numerically calculated in the 2-D model of the tank and plate heaters. The enthalpy method and FVM code was used for this analysis. The changes of the temperature with heat fluxes and the heat transfer area could be investigated. The energy balance error was found to increase with the heat flux. From this numerical analysis, the proper heat flux value and some important design factors relating local overheating and pressurization of the water tank could be examined.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.3
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• pp.437-450
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• 1996

A set of stability equations is formulated for natural convection flows adjacent to a vertical isothermal surface melting in cold pure water. It takes account of the nonparallelism of the base flows. The melting rate is regarded as a blowing velocity at the ice surface. The numerical solutions of the linear stability equations which constitute a two-point boundary value problem are accurately obtained for various values of the density extremum parameter $R=(T_m-T_{\infty})/(T_0-T_{\infty})$ in the range $0.3{\leq}R{\leq}0.6$, by using a computer code COLNEW. The blowing effects on the base flow becomes more significant as ambient temperature ($T_{\infty}$) increases to $T_{\infty}=10^{\circ}C$. The maximum decrease of heat transfer rate is about 6.4 percent. The stability results show that the melting at surface causes the critical Grashof number $G^*$ and the maximum frequency of disturbances to decrease. In comparision with the results for the conventional parallel flow model, the nonparallel flow model has a higher critical Grashof number but has lower amplification rates of disturbances than does the parallel flow model. The spatial amplification contours exhibit that the selective frequency $B_0$ of the nonparallel flow model is higher than that of the parallel flow model and that the effects of melting are rather small. The present study also indicates that the selective frequency $B_0$ can be easily predicted by the value of the frequency parameter $B^*$ at $G^*$, which comes from the neutral stability results of the nonparallel flow model.

• Ocean and Polar Research
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• v.33 no.1
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• pp.1-11
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• 2011

This study describes measurements of fast ice recorded on May 23, 2009, in Kongsfjorden (translated as 'Kongs Fjord'), an inlet on the west coast of Spitsbergen in the Svalbard Archipelago. Seasonal fast ice is an important feature for Svalbard fjords, both in relation to their physical environment and also the local ecosystem, since it grows seaward from the coast and remains in place throughout the winter. Ice thickness, snow, ice properties, and wind speed were measured, while SAR (Synthetic Aperture Radar) data was observed simultaneously observed two times from ALOS-PALSAR (L-band). Measured ice thickness was about 25-35 cm while the thickness of ice floe broken from fast ice was measured as 10-15 cm. Average salinity was 1.9-2.0 ppt during the melting period. Polarimetric data was used to extract H/A/alpha-angle parameters of fast ice, ice floe, snow and glacier, which was classified into 18 classes based on these parameters. It was established that the area of fast ice represents surface scattering which indicates low and medium entropy surface scatters such as Bragg and random surfaces, while fast ice covered with snow belongs to a zone of low entropy surface scattering similar to snow-covered land surfaces. The results of this study will contribute to various interpretations of interrelationships between H/A/alpha parameters and the wave scattering Phenomenon of sea ice.

• Ocean and Polar Research
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• v.41 no.2
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• pp.63-77
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• 2019

In order to investigate the behavior and seasonal variability of Mn as one of the bio-essential metals in the Amundsen sea, which is known as the most biologically productive coastal area around the Antartica, seawaters were collected using a clean sampling system for 10 stations (96 ea) in 2014 (ANA04B) and for 12 stations (139 ea) in 2016 (ANA06B) surveys of RV ARAON. Dissolved and particulate Mn concentration varied in the range of 0.15-4.43 nmol/kg and <0.01 to 2.42 nM in 2014 and in the range of 0.25-4.15 nmol/kg and 0.01-2.64 nM in 2016, respectively. From the sectional distribution of dissolved and particulate Mn, it might be suggested that dissolved/particulate Mn was provided from iceberg melting and diffusion/resuspension from sediments, respectively. Although this sea is highly productive, there was little evidence regarding the biological origin of dissolved Mn, but particulate Mn only in sea ice and offshore areas could be explained as originating from organic matters, e.g. phytoplanktons. And it could be suggested that the subsurface maximum of dissolved Mn was formed by isopycnal transport of melting materials from ice wall to offshore. Compared to early (2014) summer, temperature, salinity, biomass, dissolved and particulate Mn in late (2016) summer indicated that temporal variations might be resulted from the reduction of ice melting and mCDW flow, which induced a reduction in resuspension. In addition, in the late summer, particles including biomass were reduced, which brought about a reduction in the removal rate of dissolved Mn.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.793-799
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• 2015

The market sales of premium ice cream have paralleled the growth in consumer desire for rich flavor and taste. Storage temperature is a major consideration in preserving the quality attributes of premium ice cream products for both the manufacturer and retailers during prolonged storage. We investigated the effect of storage temperature (−18℃, −30℃, −50℃, and −70℃) and storage times, up to 52 wk, on the quality attributes of premium ice cream. Quality attributes tested included ice crystal size, air cell size, melting resistance, and color. Ice crystal size increased from 40.3 µm to 100.1 µm after 52 wk of storage at −18℃. When ice cream samples were stored at −50℃ or −70℃, ice crystal size slightly increased from 40.3 µm to 57-58 µm. Initial air cell size increased from 37.1 µm to 87.7 µm after storage at −18℃ for 52 wk. However, for storage temperatures of −50℃ and −70℃, air cell size increased only slightly from 37.1 µm to 46-47 µm. Low storage temperature (−50℃ and −70℃) resulted in better melt resistance and minimized color changes in comparison to high temperature storage (−18℃ and −30℃). In our study, quality changes in premium ice cream were gradually minimized according to decrease in storage temperature up to−50℃. No significant beneficial effect of −70℃ storage was found in quality attributes. In the scope of our experiment, we recommend a storage temperature of −50℃ to preserve the quality attributes of premium ice cream.

• Journal of Nutrition and Health
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• v.38 no.8
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• pp.663-671
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• 2005

The purpose of this study was to investigate not only quality characteristics such as overrun, meltdown and sensory evaluation of oligosaccharide-supplemented soy ice cream but also physiological effects of ice cream with soy and/or oligosaccharide on blood sugar and lipid profile in streptozotocin-induced diabetic rats. Powder of parched soybean was added at $7.6\%$ replacing skimmed milk and cream, soybean oil at $7.6\%$ replacing milk oil in cream, and fructooli-gosaccharide at $9.5\%$ replacing sucrose on weight basis. Five kinds of ice cream were prepared: MMS (skimmed milk, milk oil, sucrose), MMO (skimmed milk, milk oil, oligosaccharide), SSS (soybean, soybean oil, sucrose), SSO (soybean, soybean oil, oligosaccharide), and BSO (black soybean, soybean oil, oligosaccharide). Overrun and meltdown of soy ice cream were significantly lower than those of milk ice cream. Scores of sensory evaluation especially in mouth feel and melting feel in mouth were lower in soy ice cream. Freeze-dried ice cream was supplemented to AIN93-based diets at $30\%$(w/w). Sprague-Dawley male rats with diabetes induced by injecting streptozotocin were fed experimental diets for 4 weeks. Plasma glucose level was significantly lowered in SSO group compared with MMS group. Plasma insulin levels of MMO and SSO groups were not significantly different from that of normal group, while those of MMS and SSO group were significantly lower than normal group. Plasma cholesterol was decreased in groups fed ice cream supplemented either soybean or fructooligosaccharide compared to MMS group. HDL-cholesterol level was elevated and triglyceride was decreased significantly in MMO group compared to MMS group. LDL-cholesterol levels of SSS and BSO groups and liver triglyceride level of SSO group were significantly lower compared to MMS group. In conclusion, oligosaccharide-supplemented soy ice cream lowered blood sugar, and ice cream supplemented with soybean and/or oligosaccharide improved lipid profile in diabetic rats.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.137-142
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• 2015

Antifreeze proteins and glycoproteins [AF(G)Ps] constitute a group of proteins that lower the freezing but not the melting points of aqueous solutions, enabling polar and north-temperate fish to survive in ice-laden environments. However, little is known about antifreeze activity in temperate fish; such work would extend our knowledge on the functions and evolution of AF(G)Ps. In the present study, we screened for antifreeze activity in temperate fish caught off the coast of Jumunjin ($37.89^{\circ}N$), Gangneung, Korea. Thermal hysteresis (TH) and the ability to inhibit ice recrystallization (IR) in blood, liver, and muscle samples from nine fish were examined to assess antifreeze activity. As the East Sea off the coast of Jumunjin is ice-free year round, we thought it most unlikely that the fish would express antifreeze proteins. Surprisingly, the blood of Pleurogrammus azonus and three types of tissue from Gymnocanthus herzensteini, Zoarces gilli and Kareius bicoloratus exhibited measurable TH values together with the ability to trigger characteristic morphological changes in ice crystals. Blood samples from the three species also evidenced ice recrystallization (IR) inhibition. This implies that AF(G)Ps or other antifreeze-like substances are present in temperate fish even under nonfreezing conditions. These results contribute to our understanding of the functions and origins of antifreeze activity in fish.