• Title/Summary/Keyword: Water content changes

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Study on Changes of the Moisture Content of Sprayed Fire-Resistive Material according to Temperature Conditions (온도조건에 따른 내화뿜칠피복재의 함수율 변화 검토)

  • Lee, Gun-Cheol;Choi, Jung-Gu;Lee, Gun-Young;Kim, Dae-Hoi
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.212-213
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    • 2014
  • In case of fire spray protection sheath, fire resisting capacity is assessed for each material and installation method according to fire-resistive construction recognition. This study reviews effects of the percentage of water content that exist in fire spray protection sheath during the assess process of fire resisting capacity on fire resisting capacity, and changes of the percentage of water content according to temperature conditions. As a result of exams, as curing temperature is higher and thickness of specimen is thinner, decrease of the percentage of water content becomes significant.

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Change of Physicochemical Quality According to Its Storage Temperature in Garlic (Allium sativum L.) (마늘의 저장온도에 따른 이화학적 품질변화)

  • 장현세;홍경훈
    • Food Science and Preservation
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    • v.5 no.2
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    • pp.119-122
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    • 1998
  • This study was conducted to blow the effect of postharvest physiological changes on garlic quality according to its ecotypes and storage temperatures. The changes of water, total soluble solids, crude stein, md total fructans were measured and the rates of respiration and sprouting were analyzed during storage at 20$^{\circ}C$ and 30$^{\circ}C$. The decrease of water content and the increase of total soluble solids were reversely appeared during garlic storage. The crude protein content was gradually increased during storage but total fructan content was decrased. The respiration late was maximized at 60days after storage and the spouting rate was gradually increased. In the aspect of ecotypic characteristics, the water content, fructan content and sprouting rate were higher in 'Namdo' cultivar than those of southern type. The high storage temperature (30$^{\circ}C$) controlled spouting and loss of fructan, and it was effective to maintain the garlic quality.

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Changes of Microbiological Distribution in Food Waste for Animal Feed (동물 사료화를 위한 음식물 쓰레기의 미생물 분포 변화)

  • 김판경;박승춘;김명희;오태광;손천배
    • Journal of Veterinary Clinics
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    • v.15 no.1
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    • pp.156-161
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    • 1998
  • This study investigated the microbiological changes and distribution of bacteria producing enzyme in order to change food wastes to animal feed during 6 days at room temperature. Food wastes were divided as follows: one is untreated food wastes containing 80% water content and another wastes containing 40% water content adiusted by wheat bran. During the fermentation of food wastes, Lactobacillus sp. and Streptococcus sp. were grown the top position among investigated microorganisms in both of food wastes. Numbers of total microorganisms were much more than untreated wastes during fermentation of flood wastes with 40% water content. But, Streptococcus sp. and Enterobacteriaceae from 4 to 6 days were not detected in treated wastes with 40% water contents. This fact indicated that the adiustment of water content in food waste was effective in fermentation. However, the numbers of microorganisms producing pretense were low in both treated and untreated food wastes. These results suggested that flood wastes should be treated as food wastes with 40% water content to maintain a lot of fermentative microorganisms such as Lactobacillus sp., Streptococcus sp. and yeasts together with pretense to make final animal feed.

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Changes in Drug Elution Concentration and Physical Characteristics of Soft Contact Lenses Depending on the Initiator and Crosslinker (개시제와 교차결합제 농도의 변화에 따른 소프트콘택트렌즈의 물리적 성질과 약물용출 농도의 변화)

  • Park, Hyun-Ju;Lee, Hyun Mee
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.2
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    • pp.145-151
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    • 2014
  • Purpose: The material properties of contact lenses were measured by varying the amounts of an initiator and a cross-linking agent that are the basis for the manufacture of contact lenses, and the drug delivery effects depending on the material properties of contact lenses were compared. Methods: Contact lens samples were manufactured using HEMA by varying the concentration of the cross-linking agent and the initiator. To investigate the changes in physical characteristics depending on the material properties, the results of the experiments on the amount of drug elution, water content, refractive index, and the amount of protein adsorption were compared. Results: For the contact lenses manufactured by varying the amount of the initiator, the water content hardly changed, and the refractive index also hardly changed. The amount of drug elution was not much affected by the changes in the initiator, but the amount of elution increased as the water content increased. The amount of protein adsorption was hardly affected by the changes in the initiator, but the amount of adsorption increased as the water content decreased. Conclusions: The changes in the properties were hardly affected by the changes in the amount of the initiator, but were significantly affected by the changes in the amount of the cross-linking agent. As the amount of the cross-linking agent increased, the water content decreased, while the refractive index increased. Also, when the water content increased, the amount of drug elution increased, while the amount of protein adsorption decreased.

Changes in Leaf Water Potential, Lethal Temperature and Carbohydrate Content of Wintergreen (Pyrola japonica Klenze) during Overwintering (越冬 중 노루발의 水分포텐셜, 致死溫度 및 炭水化物量의 變化)

  • Ryu, Beungtae;Joon-Ho Kim
    • The Korean Journal of Ecology
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    • v.13 no.1
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    • pp.59-66
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    • 1990
  • Changes in water potential, lethal temperature and carbohydrate content in the leaves of wintergreen (Pyrola japonica) during overwintering were investigated. Leaf water potential was kept at -2 bars in the tender stage before October, decreased to -46 bars in the dormancy stage and increased to -2 bars again after dehardening Lethal temperatures of the leaf tissue were $-7^{\circ}C$ in the tender stage and $-7^{\circ}C$ in the dormancy stage, but did not recover up to that of the tender stage during dehardeding. Peak of soluble sugar content coincided with the nadir of the leaf water potential. There were close relationships among daily minimum air-temperature, leaf water potential and lethal temperature in changing patterns during overwintering.

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Changes in Water Content Affect the Post-Milling Quality of Paddy Rice Stored at Low Temperature

  • Kim, Young-Keun;Hong, Seong-Gi;Lee, Sun-Ho;Park, Jong-Ryul;Choe, Jung-Seob
    • Journal of Biosystems Engineering
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    • v.39 no.4
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    • pp.336-344
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    • 2014
  • Purpose: In this study, the effect of milling on paddy rice stored at low temperature, the changes in grain temperature of bulk storage bags exposed at room temperature, the post-milling water content of paddy rice, the whiteness of rice, and the rate of pest incidence were investigated and data were analyzed. Methods: Changes in temperature inside the bulk storage bags kept at low temperature and grain temperature after exposure to room temperature were measured. Experiments were conducted for identifying the reasons of post-milling quality changes in paddy rice stored at low temperature. Results: It was determined that a short-term increase of water content in paddy rice was directly related to surface condensation, and that rice should be milled at least 72 h after removal from low-temperature storage, in order to completely eliminate surface condensation of paddy rice kept in bulk storage bags. It was observed that post-milling quality of rice changed, but water content was maintained at high levels for more than 18 d in rice that was milled when condensation occurred, regardless of paper or vinyl packaging. Rice whiteness rapidly decreased in rice that was milled when condensation occurred, regardless of packaging, while rice that was milled 72 h or more after removal from low temperature storage did not show any significant changes in whiteness. No pest incidence was observed up to 12 d after removal from low temperature storage, regardless of packaging. Starting at 18 d, after removal from low temperature storage, rice that was milled when condensation occurred, was affected by pests, while 24 d after removal from low temperature storage, all portions of rice were affected by pests. Conclusions: Our results suggest that changes in post-milling quality of rice could be significantly reduced by exposing paddy rice to room temperature for at least 72 h before milling, in order to allow the increase of grain temperature and prevent surface condensation.

The changes of pectic substances of $emph{Kimchis}$ with different garlic contents during the fermentation periods (마늘첨가량을 달리한 김치의 펙틴질의 변화)

  • 유은주;신말식;전덕영;홍윤호;임현숙
    • Korean journal of food and cookery science
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    • v.4 no.1
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    • pp.59-63
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    • 1988
  • The changes of acidity, the content of alcohol-insoluble solid (AIS) and pectic substances of Kimchis which were prepared with various garlic contents and fermentation at $21^{\circ}C$ were investigated. Acidity and the content of water soluble pectin of Kimchis increased but the content of AIS and protopectin decreased during the fermentation. As the Kimchis contained high garlic contents compared with the Kimchis deleted garlic, acidity of those rapidly increased but the content of AIS of those slightly decreased with fermentation. In the case of Kimcltis contained high garlic contents, protopectin decreased and water soluble pectin increased with fermentation, but the amount of changes was small.

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Fundamental Characteristics of Mortar According to the Changes in the Solid Content Rate of the Water-Reducing Agent (감수제의 고형분율 변화에 따른 모르타르의 기초적 특성)

  • Kim, Min-Sang;Lee, Jae-Jin;Hyun, Seong-Yong;Kim, Tae-Woo;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.156-157
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    • 2017
  • It is possible in the case of the chemical admixtures for concrete currently being used in actual work sites to omit quality evaluation and replace it with the scores of the admixture manufactures; this can create a problem of decline in reliability in quality on the work site. Therefore this study sought to analyze the degree of influence changes in the solid content rate of lignin- and naphthalene-based water-reducing agents have on the fundamental characteristics of cement mortar. The results showed that in fresh mortar, the flow and amount of air decreases with decrease in the solid content ratio. In hardened mortar, the condensation strength had hardly any effect on the use of lignin-based water-reducing agent, but naphthalene-based water-reducing agent increased with the decrease in the solid content ratio.

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Changes in the Content of Individual Phenolic Compounds in Apple Slices during Cold Storage (냉장저장 중 사과슬라이스의 개별페놀성분함량과 제변화)

  • Ahn, Sun-Choung
    • Journal of the Korean Society of Food Culture
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    • v.23 no.4
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    • pp.489-498
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    • 2008
  • The objectives of this study were to provide fundamental information on how individual phenolic compounds form on the inside of apple slices during cold storage, the changes in the content of four types of phenols, ingredient variation of individual phenolic compounds and the influence of phenolic compounds on enzymatic browning. This study measured the changes in the content of soluble solids, pH and vitamin C in order to investigate the correlations between these variables. HD and FA were the main phenolic compounds found in the apple slices, and HD was the most prevalent phenol. Furthermore, comparison of the CG and EP content revealed that there were more CGs than EPs. The phenol content tended to decrease considerably in the fresh apple slices and water-dipped apple slices but only slightly in the CP from sucrose-dipped apple slices and 0.5% ascorbic acid solution-dipped apple slices. The degree of browning increased in the following order: fresh apple slices, water-dipped apple slices, 0.5% ascorbic acid solution-dipped apple slices and CP from sucrose-dipped apple slices. The vitamin C content tended to decrease in the fresh apple slices, water-dipped apple slices, 0.5% ascorbic acid solution-dipped apple slices and CP from sucrose-dipped apple slices. The pH tended to increase in all sample groups, but the pH of the water-dipped apple slices was lower than that of the comparison group. The CP from sucrose-dipped apple slices had the lowest value of pH. The change in soluble solids tended to increase in all treatment groups, but this increase was less in the CP from sucrose-dipped apple slice. Correlation analysis revealed a high degree of correlation between browning and chlorogenic acid content. The results of the present study show that, when stored in the fridge, the change in phenol ingredient content in apple slices influences the browning of the slices. The results also showed that HD and FA were the main phenolic compounds, while CG was shown to have the greatest influence on browning.

A Study on Soil-Water Characteristic Curves of Reclaimed Soil and Weathered Granite Soil (준설매립토 및 화강풍화토의 흙-수분 특성곡선에 관한 연구)

  • 신은철;이학주;김환준
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.743-750
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    • 2002
  • Unsaturated soil has a possibility to induce a negative pore water pressure. Until now, saturated soil is mainly focused on the research of soil mechanics. Recently, soil mechanics is researched on two major parts such as saturated and unsaturated soil mechanics. Negative pore water pressure has a non-linear relationship with the water content changes. Soil-water characteristic curves of soil in Korea are not determined. There is no proper characteristic value such as air-entry value and residual water content. In this study, the characteristic curves of reclaimed soil, sand, and weathered granite soil were determined by laboratory tests. Air-entry value and residual water content were determined by fitting methods. Soil-water characteristic curves were estimated based on the particle-size distribution and compared with the laboratory test results. The results of soil-water characteristic curves estimation indicated that Fredlund and Wilson's model is excellent for sand and weathered granite soil. Arya and Paris's model is excellent for reclaimed soil.

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