• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.2
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• pp.183-190
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• 2005

In the process of ice-slurry making, ice adhesion on cooling wall or in narrow flow Path disturbs continuous ice formation. In this study, the effect on the ice adhesion to cooling surface by some freezing experiments was investigated, quantitatively. Three types of solutions were frozen in various coating vessels with stirring. In the experiment, the ice adhesion between cooling wall and Ice-slurry was evaluated by measuring stirring power. From the result, the stirring power of slurry mixture in PTFE-coating vessel was smaller than those in PE-coating, PFA-coating and bare SUS vessel. Especially, in EG H PG 1.S/ HD 1.5 mass$\%$ solution, the stirring power in the PE-coating vessel was smaller than that in the PFA-coating or SUS vessel.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.627-634
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• 2012

This study was carried out to investigate the physical and thermal properties of ${\kappa}$-carrageenan (${\kappa}$-car) gel added whey protein isolate (WPI) as a cryoprotectant. The concentration of ${\kappa}$-carrageenan was fixed at 0.2 wt%. The mean ice crystal size of the WPI/${\kappa}$-car was decreased according to increasing whey protein isolate concentration. The temperature of gel-sol (Tg-s) and sol-gel (Ts-g) transition of WPI/${\kappa}$-car maxtrix was represented in the order of 3.0, 0.2, 5.0 and 1.0 wt%. In addition, the transition temperature of gel-sol of WPI in sucrose solution were showed in order of 1.0, 5.0, 0.2 and 3.0 wt% depending on whey protein isolate concentration. The shape of ice crystal was divided largely into two types, round and rectangular form. 1.0 wt% WPI/${\kappa}$-car matrix at pH 7 and 9 showed minute and rectangular formation of ice crystals and whey protein isolate in sucrose solution at a concentration of 1.0 wt% WPI/${\kappa}$-car matrix at pH 3 and 5 showed relatively large size and round ice crystals. The ice recrystallization characteristics and cryprotective effect of ${\kappa}$-carrageenan changed through the addition of different concentrations of whey protein isolate. It seems that the conformational changes induced interactions between whey protein isolate and ${\kappa}$-carrageenan affected ice recrystallization.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.721-727
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• 2006

This study was carried out to investigate the effect of hydrocolloids on the changes in physical properties of a model ice cream. The model ice cream contained water, sugar, skin milk powder, com oil, and 4 different hydrocolloid stabilizers (gelatin, pectin, hydroxyethylstarch, locust bean gum), was manufactured in a batch type freezer. The following physical characteristics of ice cream were examined: flow behavior, overrun, air cell size, ice crystal size, and melt resistance. With regard to flow behavior, all of aged mixes had a lower apparent viscosity relative to the mix before aging, and ice cream mix containing locust bean gum had the highest viscosity. Air cell size was observed to range from 20 to $38\;{\mu}m$, and ice cream with locust bean gum showed the largest size. There was an inverse correlation between overrun and air cell size. The ice crystal sizes of all samples ranged from 25 to $35\;{\mu}m$. Ice cream with added pectin contained the smallest ice crystal size, which was significantly difference from other stabilizers (p<0.05), and resulted in superior melt resistance with increased melting time compared to other samples.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.9
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• pp.496-504
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• 2009

In order to investigate the feasibility of a direct ice slurry transporting system for the purpose of district cooling, a case study of field application is performed. The research aims include the field measurement of ice packing factor, the performance of coldness delivery, and the branching characteristics of ice slurry. Two representative types of pipe branch are dealt with in this work. For the slurry flow with ice volume fraction of 0.16 or less, the pipe blocking due to aggregation is not observed. Based on the time-wise variation of temperature in the storage tank, a calculating method of ice packing factor is newly developed, which seems to be useful when the brine concentration is unknown. It is confirmed that the mass flow rate of ice slurry per unit cooling load is markedly reduced with increasing the ice content. The pumping power also decreases, but remains unchanged for high ice fractions. The distribution of ice particle before and after branching shows a good uniformity within the range of 5% difference, but yields a unique trend depending on the flow rate.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.5
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• pp.509-516
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• 2007

Ice load acting on a icebreaking research vessel is estimated. Existing measured ice loads are used to get the global load and the local load. The global load is for analyzing the bending behavior of the vessel during ice breaking operation mode and the local load for estimating the bow structural behavior. In the paper, the global load is predicted using the data from analysis of ship motion during ice breaking. And the local load is predicted using the data from strain gage attached to bow frames.

• 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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.5
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• pp.653-659
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• 2001

This paper is concerned with the development of a new method for making and separating ice in-water and saving floated ice by installing an evaporation panel in an ice storage tank. The new method shows very good heat transfer efficiency than that of the convectional method. It is because the evaporation panel is directly contacted with water in the storage tank. The experiments were performed by varying inlet and outlet refrigerant temperatures of its evaporator. From the experimental results, the operating characteristics of in-water harvest-type ice storage system were investigated by measuring temperature and pressure at each point of the ice storage system and power required to operating compressor respect to the changes of the inlet and outlet refrigerant temperature of evaporator. It can be think that defrost frequency decreased and heavy ice created as the refrigerant temperature of evaporator outlet and defrost setting temperature is low so gotten result can effect to release efficiency. Also, consumption power, condensing heat quantity, refrigerating capacity and performance efficiency decreased as time goes by. Therefore, these results provide the basic data for system optimization, performance improvement and the possibility of application to other fields.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.202-206
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• 2014

In this study, the bacteriological survey was examined on ice creams at manufacturing factories in Korea during the summer season of 2011. The nineteen selected among 166 samples by preliminary test were collected from 11 different manufacturing factories in four major manufacturers in May 2011. Samples from ice milk, ice creams, sherbets, and non milk fat ice creams were tested for the total aerobic bacteria, coliform bacteria, and five food borne pathogens, respectively. The results showed that the coliforms including E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Clostridium perfringens, and Listeria monocytogenes were not detected on all the ice creams. The total aerobic bacteria of the packed samples examined ranged between $2.5{\times}10^3$ and $5.5{\times}10^5cfu/g$. One ice cream, two sherbets, and four ice milk samples exceeded the acceptable limits of total aerobic bacteria according to the Korean standards for ice cream ($1.0{\times}10^5cfu/g$) and others ($5.0{\times}10^4cfu/g$). The levels of these microorganisms from ice creams were higher in three original equipment manufacturers than seven self-manufacturers. Three of ten ice creams (30.0%), three of six ice milks (50.0%), and one of two sherbets (50%) exceeded the acceptable limits of total aerobic bacteria, respectively. The personnel hygiene procedures with chocolate and vanilla chip addition from the manufacturing process were the main sources of the microbial contamination of stick-bar type ice creams when being produced in a factory. Improvement of the hazard analysis critical control points (HACCP) system should be introduced into the ice cream factory to improve the microbial quality of the ice cream products in Korea.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.23 no.5
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• pp.414-420
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• 1994

• Journal of the Society of Naval Architects of Korea
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• v.49 no.6
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• pp.478-483
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• 2012

The speed performances of ice sea trial on the Arctic(2010 & 2011) area were shown different results depend on the ice floe size. Penetration phenomena of level ice was not happened on medium ice floe and tore up by the impact force because the mass of medium ice floe is similar to the mass of Araon which is Korean ice breaking research vessel and did not shut up by the ice ridge or iceberg. The sea trial on the Amundsen sea was performed at the big floe which is classified by WMO(World Meteorological Organization). Three measurements of ice properties and five results of speed trial were obtained with different ice thicknesses and engine powers. To evaluate speed of level ice trial and model test results at the same ice thickness and engine power, the correction method of HSVA(Hamburg Ship Model Basin) was used. The thickness, snow effect, flexural strength and friction coefficient were corrected to compare the speed of sea trial. The analyzed speed at 1.03m thickness of big floe was 5.85 knots at 10MW power and it's 6.10 knots at 1.0m ice thickness and the same power. It's bigger than the results of level ice because big floe was also slightly tore up by the impact force of vessel based on the observation of recorded video.