• Title/Summary/Keyword: frozen ground

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A study of energy saving and long conservation in construction of rock store house (암반 저장창고 건설을 통한 에너지 절감과 장기보존에 대한 연구)

  • 최예환;채경희
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.210-216
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    • 1998
  • The most important thing to consider in cold store design are to save cooling energy consumption and to keep goods freshly. Specially there are many efforts to save energy with cold store in Korea. A building energy simulation program should be used to optimally select a cooling system to match the criteria of cooling rate and storage rate in a given cool crop storage building and HVAC system. The low maintenance costs, high degree of safety and environmental impacts are also favouring the underground solution. There are obviously a lot of possibility for cost-effective storage of cooled or frozen goods or liquids in ground water rock.

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Evaluation of Frost Heave Prediction and Frost Susceptibility in Sample using JGS Test Method (일본 동상성판정기준을 적용한 시료의 동상예측 및 동상성 평가)

  • Kim, Young-Chin;Hong, Seung-Seo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.926-931
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    • 2008
  • This paper show two different standardized test methods(Japanese Geotechnical Society; JGS 2003). One test is a "Test Method for Frost Heave Prediction Test, JGS 0171-2003", and the other test is a "Test Method for Frost Susceptibility, JGS 0172-2003". The purpose of this test is to obtain the freezing rate(freezing speed), frost heave ratio(heave to sample height), frost heave rate(heaving speed), and other parameters to be used for frost heave prediction and determine the frost susceptibility by freezing test with water intake. This method shall be used to predict the frost heave in frozen ground and evaluate the frost susceptibility of natural and replacement materials.

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Investigation on the Method of Evaluating the Resistance to Freezing and Thawing of Concrete Subjected Initial Frost Damage (초기동해를 받은 콘크리트의 내동해성 평가법에 대한 검토)

  • 고경택;장일영
    • Journal of the Korea Concrete Institute
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    • v.11 no.4
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    • pp.117-127
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    • 1999
  • In concrete incorporating high volume ground granulated blast-furnace slag that has frozen at early age, to evaluated the results of resistance to freezing and thawing is very difficult because the hydration of the concrete increases over the duration of rapid freezing and thawing test. Hence, the dynamic modulus of elasticity of specimens after freezing and thawing will be favorable results unless the hydration effect is taken into consideration. In this study, a method of evaluating to the resistance to freezing and thawing of concrete subjected freezing at early age, in which the effect of hydration is modified for its increase during rapid freezing and thawing test, is investigated.

Frost Heaving Pressure Characteristics of Frozen soils with Frost-Susceptibility and Degree of Saturation (흙의 동상민감성과 포화도를 고려한 동상팽창압 특성)

  • 신은철;박정준;김종인
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.329-336
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    • 2002
  • The earth structures and in-ground LNG tank, and buildings can be constructed with using artificial freezing method on the reclaimed land. In this study, upon freezing a saturated soil in a closed-system from the top, a considerable pressure was developed. The pressure is the result of the surface energy of a curved ice-water interface. The most significant of these parameters will have the greatest effect on the classification. In order to establish frost-susceptibility criteria based on frost heaving expansion pressure, more soils have to be tested. This study was initiated to investigate the soils frost heaving expansion pressure and moisture characteristics resulting from freezing and freezing-thawing cycle process. Weathered granite soils, sandy soil, sandy soil were used in the laboratory freezing test subjected to thermal gradients under closed- systems.

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Heat Transfer Equation and Finite Element Analysis Considering Frozen Ground Condition the Cyclic Loading (지반의 동결조건을 고려한 열전도 구성방정식과 유한요소해석)

  • Kim, Young-Seok;Kang, Jae-Mo;Hong, Seung-Seo;Kim, Kwang-Jin
    • Journal of the Korean Geosynthetics Society
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    • v.9 no.3
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    • pp.39-45
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    • 2010
  • When the ground temperature drops below $0^{\circ}C$, wet soils expand due to the ice formation in their porous space. This results in frost heave which causes structural stability problems. Frost heave is attributed by several factors such as physical soil properties and heat transfer including pore water phase change. Due to the complex physical phenomena, reliable and verified multi-dimensional numerical models for frost heave problems are still in a research stage. This study presents an efficient and simple method of overcoming numerical problems associated with sudden jump of heat capacity due to the phase change from water to ice in the pore space. This paper proposes heat transfer equation and finite element method when the saturated soils or porous rocks are subjected to freezing. Numerical analyses using the proposed method agree well with the known closed form solution and the laboratory test results.

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Antimicrobial Activity of Korean Leek and Its Application to Food System (부추의 항균활성 특성과 식품에의 응용)

  • 홍정화;이미형;전치수;허성호
    • Journal of Food Hygiene and Safety
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    • v.14 no.4
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    • pp.422-427
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    • 1999
  • Antimicrobial activity of Korean leek was effective on Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, E. coli O157:H7, Pseudomonas fluorescens, Pichia membranaefaciens. Extract from raw Korean leek and that from frozen one showed antimicrobial activity; in contrast, extract stored frozen condition or extract from blanched one lost antimicrobial activity. Filtration, centrifugation, and vacuum concentration did not affect antimicrobial activity of the leek, nor did the changes in storage pHs. Addition of ground leek to soy milk, soy curd, and broth for cold noodle resulted in the prolonged shelf life by significantly reducing the number of viable cells.

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Quality Characteristics of Non-cooked Meat Patties with Ground Raw Tomato During Freeze Storage (토마토가 함유된 비가열 미트패티의 냉동 저장 중 품질특성)

  • Kim, Il-Suk;Jin, Sang-Keun;Min, Hun-Sik;Yang, Mr-Ra;Nam, Young-Wook;Ko, Byung-Soon;Shon, Han-Kyu
    • Journal of Animal Science and Technology
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    • v.50 no.4
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    • pp.535-542
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    • 2008
  • The effects of tomato on the phsycochemical and sensory properties of meat patties during frozen storage were studied. Meat patties were produced with four different formulation including 0, 0.5, 1.0 and 1.5% chopped raw tomato. Meat patties made with the addition of tomato had higher(p<0.05) pH, L* and a* value than those of control sample. TBARS of all treatments were lower(p<0.05) when compared with those for control. In sensory evaluation, treatment groups resulted in slightly higher(p>0.05) score in overall acceptability. In the manufacture of functional meat patties containing tomato, further studied are needs on addition type and ratio of tomato materials during frozen storage than those of products without tomato.

Thermochemical Performance Analysis of Liquid Rocket Nozzle (액체로켓 노즐의 열화학적 성능 해석)

  • Choe,Jeong-Yeol;Choe,Hwan-Seok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.1
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    • pp.85-96
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    • 2003
  • For a design of rocket engine nozzle, chemical equilibrium analysis which shares the same numerical characteristics with frozen flow analysis can be used as an efficient design tool for predicting maximum thermodynamic performance of the nozzle. 10 this study, a chemical equilibrium flow analysis code was developed for the design of hydrocarbon fueled rocket engines. 10 oder to understand the thermochemical characteristics occurring in a nozzle through the expansion process, such as recombination of chemical components and the accompanying energy recovery, chemical equilibrium flow analysis was carried out for the KSR-III rocket engine nozzles together with frozen flow and non-equilibrium flow analyses. The performance evaluation based on the present KSR-III nozzle flow analyses has provided an understanding of the thermochemical process in the nozzle and additionally, it has confirmed that the newly designed nozzle shape modified to have a reduced exit area ratio is an adequate design for obtaining an increased ground thrust.

Evaluation on the Reliability of Frost Susceptibility Criteria (동상민감성 판정 기준 신뢰성에 관한 연구)

  • Jin, Hyunwoo;Ryu, Byunghyun;Lee, Jangguen
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.12
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    • pp.37-45
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    • 2017
  • Structural instability and damage are caused by frost heave during the winter when atmospheric temperature maintains below $0^{\circ}C$. Frost heave is the most representative engineering characteristics of frozen ground and there are various frost susceptibility criteria. Frost susceptibility criteria can be roughly divided into three categories. First, frost susceptibility is determined from particle size distribution, which is practically useful and many countries are adopting. In this paper, several particle size distributions (PSDs) are applied to the frost susceptibility criteria but PSD seems to be not enough to determine whether soils are frost susceptible. Second, it is judged from laboratory frost heave testing results. Laboratory frost heave tests were performed with newly developed thermal controlled triaxial cell and the reliability of frost susceptibility criteria is evaluated. New testing apparatus and method are suitable to meet the existing frost susceptibility criteria. Third, it is compositive frost susceptibility criteria envelope including the particle size distribution, soil classification, and frost heave test. The compositive frost susceptibility criteria envelope should be supplemented based on additional data on various soil types.

Effects of Carcass Processing Method and Curing Condition on Quality Characteristics of Ground Chicken Breasts (분쇄 계육 가슴살의 도체가공방법과 염지조건이 품질특성에 미치는 영향)

  • Choi, Ji-Hun;Kim, Il;Jeong, Jong-Youn;Lee, Eui-Soo;Choi, Yun-Sang;Kim, Cheon-Jei
    • Food Science of Animal Resources
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    • v.29 no.3
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    • pp.356-363
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    • 2009
  • This study was carried out to investigate the effect of hot boning and curing condition on the quality characteristics of ground chicken breast. Treatments were cured by four conditions follows; control (general curing method), T1 (after hot-boning and then immediately cured), T2 (after hot-boning and immediately cured, then frozen), and T3 (after hot-boning, immediately frozen, refrigerated and then cured). The pH of chicken breast in the state of pre-rigor was 6.22. The pH of cold storage or freezing chicken breast meat respectively were 5.70 or 5.61. The pH of T1 and T2 treatments were significantly higher than those of control and T3 treatment (p<0.05). After stored for 1 wk, the pH value of T1 treatment had a higher value than those of other treatments. T1 treatment had the highest water holding capacity and the lowest cooking loss among all treatments, regardless of the cooking methods. The reduction in diameter for T1 and T2 treatments was lower than those of control and T3 treatment (p<0.05). T1 treatment had the lowest fat loss and moisture loss among all treatments, and the emulsifying capacity of T1 treatment was the highest. The protein solubility of T1 treatment was significantly lower than that of T3 treatment.