• Title/Summary/Keyword: Thermal changes

Search Result 1,963, Processing Time 0.024 seconds

Scientific Investigation for Conservation Methodology of Bracket Mural Paintings of Daeungjeon Hall in Jikjisa Temple (직지사 대웅전 포벽화 보존방안을 위한 과학적 조사)

  • Lee, Hwa Soo;Kim, Seol Hui;Han, Kyeong Soon
    • Journal of Conservation Science
    • /
    • v.34 no.2
    • /
    • pp.107-118
    • /
    • 2018
  • This report does studied for making the method of conserving bracket murals in Daeungjeon of Jikjisa Temple, through the scientific way. Results of evaluated the conservation status at the braket mural paintings, most serious damage is structural damage like cracks, breakage, and delamination. After optical investigation, a characteristic point wasn't found such as underdrawing or traces of a coat of paint. The ultrasonic examination speed by each wall painting was measured from about 195.8 m/s to 392.7 m/s, according to the location of the surface, and it was able to compare the surface properties according to the location. In Infrared-thermal image measurement shows that wall layer separation and paint layer delamination are closely detected, therefore it was able to judge of damage on the objective way. Material analysis revealed that the walls were made by sand and weathering soil. The wall layer combined sand with less than fine sand size by nearly 5:5, and the finishing layer was found to have mixed medium sand and fine sand at approximately 6:4 rates. However, In case of finishing layer, mixing ratios of sizes less than very fine sand were found to be significantly lower than wall. Therefore, it is estimated that the plysical damage such as the separation between the layers of the walls created in the braket mural paintings, is continuously caused by changes in the internal stresses and volume ratio caused by the density differences between the wall and the finishing layers.

Studies on Physicochemical and Biological Properties of Depolymerized Alginate from Sea tangle, Laminaria japonicus by Thermal Decomposition 8. Effects of Depolymerized Alginate on Serum Lipid Composition and Its Single-Dose Toxicity yin Oral Route in Rats (다시마 (Laminaria japonicus) Alginate의 가열가수분해에 따른 물리$\cdot$화학적 및 생물학적 특성에 관한 연구 8. 저분자 Alginate투여에 의한 랫드의 혈청지질의 성분 변화 및 경구급성독성 실험)

  • KIM Yuck-Yong;CHO Young-Je
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.34 no.3
    • /
    • pp.173-178
    • /
    • 2001
  • This study was performed to know the hypocholesterolemic effect of depolymerized alginate obtained by hydrolysis of alginate through a heating process at $121^{\circ}C$. The changes of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipid levels in serum, as well as the atherogenic index were elucidated in rats for 35 days. In order to evaluate single-dose toxicity of HAG-50 in rats via oral routes, induction any mortalities and abnormal signs in clinical finding, body weight, gross findings and histopathological finding, and estimation of $LD_{50}$ were elucidated. Total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipid levels in the serum significantly decreased and resulted in the decrease of atherogenic index in rats fed diets containing $5\%\;and\;10\%$ HAG-50 (p<0.01). HAG-50 did not induce any mortalities and abnormal signs in clinical findings, body weights, gross findings and histopathological findings in single-dose toxicity test via oral routes of rats, after which it was impossible to estimate $LD_{50}$ values.

  • PDF

Electrochemical Characterization of Cobalt Oxide Xerogel Electrode for Supercapacitor (수퍼커패시터용 산화코발트 건조겔전극의 전기화학적 특성)

  • Kim Han-Joo;Shin Dal-Woo;Kim Yong-Chul;Kim Seong-Ho;Park Soo-Gil
    • Journal of the Korean Electrochemical Society
    • /
    • v.3 no.3
    • /
    • pp.146-151
    • /
    • 2000
  • So fine cobalt oxide xerogel powders were prepared by using a unique solution chemistry associated with the sol-gel process. The effect of thermal treatment on the crystalinity, particle structure, and corresponding electrochemical properties of the resulting xerogel remained amorphous as $Co(OH)_2$ up to $160^{\circ}C$ With an increase in the temperature above $200^{\circ}C$, both the surface area and pore volume decreased sharply, because the amorphous $Co(OH)_2$ decomposed to form CoO that was subsequently oxidized to form crystalline Co304. In addition, the changes in the crystallinity, and particle structure all had significant but coupled effects on the electrochemical properties of the xerogels. A maximum capacitance of 192F1g was obtained for an electrode prepared with the $CoO_x$ Xerogel calcined at$150^{\circ}C$, which was consistent with the maxima exhibited in both the surface area and pore volume. This capacitance was attributed solely to a surface redox mechanism.

Processing and Storage of Spinach Products Using Cook-chill and Sous Vide Methods (Cook-Chill 및 Sous Vide 방법에 의한 시금치 식자재의 가공 및 저장)

  • 김기태;구경모;백현동;류은순;이동선
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.30 no.6
    • /
    • pp.1095-1101
    • /
    • 2001
  • Spinach was minimally processed into the unseasoned side dish to be used for Korean food service industry, using the techniques of cook-chill and sous vide. Spinach was blanched at 10$0^{\circ}C$ for 6 minutes, vacuum-packaged in the unit of 500 g by plastic film of low gas permeability, pasteurized at 9$0^{\circ}C$ and then cooled rapidly at 3$^{\circ}C$. The chilled products were then stored at 3 and 1$0^{\circ}C$ with measurement in their quality. Six log cycle (6D) inactivation of Listeria monocytogenes and 13 log (13D) thermal destruction of Streptococcus faecalis were compared as two pasteurization conditions, which corresponded to heating for 22.8 and 30.0 minutes at 9$0^{\circ}C$, respectively. Milder heat processing based on 6D process of L monocytogenes gave better quality of color, texture, ascorbic acid and chlorophyll than the conditions of 13D process of S. faecalis. Any microbial growth in total aerobic, psychrophilic and anaerobic bacteria was not observed until 8 days at 1$0^{\circ}C$ and 14 days at 3$^{\circ}C$, which might be regarded as strict guidelines of shelf life. Storage times based on the changes in physical and chemical quality were longer than those based on strict microbial quality in case of the products pasteurized by 6D process of L. monocytogenes. The seasoned vegetables prepared from sous vide processed spinach were found to be inferior in sensory quality to those from freshly blanched one.

  • PDF

Chemical Changes of the Deep Fat Frying Oils Used Commercially (일반시장에서 튀김식품에 사용된 기름의 화학적 변화)

  • Joo, Kwang-Jee;Ha, Gy-Sook
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.18 no.3
    • /
    • pp.247-254
    • /
    • 1989
  • In deep-fat frying, the fats and oils are used over and over again, and moisture and air are mixed in to the hot oil. Many reports related to these fats and oils have been established that thermal and oxidative decomposition products and polymers formed under the conditions of deep fat frying are harmful to health. This work was carried out with 3 domestic frying oils and 6 used oils commercially, and that there were difficulties in finding a good definition between fresh oil and used oil with adding unheated oil. As starting materials, commercially used soybean oil and rapeseed oil already passed over induction period in the lipids oxidation standard. From the qualitative point of view, they were inferior to domestic frying oils. Free fatty acid and peroxide value of heated oils were increased gradually by the time pass whereas iodine value were decreased. After adding unheated oil to the heated oil, these values were restored to that of initial levels. On the other hand, content of polar components in the heated oil were directly related to the heating time. This result showed that polar compounds may be a clear indicator of used oils. Fatty acid composition in the used oils, unsaturated fatty acids such as linoleic and linolenic acid decreased while saturated fatty acid content increased with heating.

  • PDF

Self-management techniques and subsequent changes in pain and function in patients with chronic low back pain (만성 요통 환자의 자가 관리 요법에 따른 통증 및 기능의 변화)

  • Choi, Jun Hyun;Kim, Eun-Shil;Yoon, Yong-Soon;Kim, Ka-Eun;Lee, Mi-Hyun;Jang, Hong-Young
    • Journal of Digital Convergence
    • /
    • v.18 no.10
    • /
    • pp.547-555
    • /
    • 2020
  • To investigate the effects of self-management programs for chronic low back pain (LBP), 63 subjects were assigned to three groups; self-exercise group (SEG), hot pack and low-frequency electrical stimulation group (HEG), and thermo-massage group (TMG). Parameters were the pain numeric rating scale (PNRS), Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire (RMDQ) and Relapse frequency (RF). PNRS, ODI and RMDQ of SEG and TMG sustained effectiveness, however, PNRS, which improved after treatment in HEG, worsened in 6 month. Between the groups, all parameters were better in SEG and TMG compare to HEG. Exercise and thermo-massage can be considered as useful self-management performed at home to prevent the relapse of chronic LBP.

Studies on the Natural Mortality of the Young Short Necked Clam, Tapes japonica-I. Seaonal Variation of the tidal Temperature, Sainity , and the Effect of Overflowing Fresh Water on the Subterranean Salinity of the Tidal Flat at Low Tide (바지락 치패의 폐사에 관한 연구-I 간척지의 간출시에 있어서의 온도, 염분변화와 유입하천수의 지하염분에 미치는 영향)

  • CHOE, Sang
    • The Korean Journal of Zoology
    • /
    • v.9 no.1
    • /
    • pp.1-6
    • /
    • 1966
  • Frequently , large masses of the young short necked clam, Tapes japonica , die at their tidal flats in summer and this phenomenon has not been explained clearly. The purpose of the present investigation is to study the thermal condition and the chlorinity level of tidal flats in which the young clam appears to be injured. A study is also mad efor the burrowing organism in the lower layer of the esturay over which the fresh water flow during the low tide. Observation are made at five places of the tidal flat near Ikawazu Fixheries Laboratory of Tokyo University during the ebb and flow tide period of the spring tide. The diurnal and monthly changes of tidal temperatures and chlorinities are measured. Results of the study are ; 1. The surface temperature of the tidal flat increases with the ebb tide, reaches the highest between 12-14PM, and gradually decreases thereafter. The temperatures of tidal flat below 5 and 10 cm increase gradually until the flow tide reaches the surface. 2. At the spring tide in summer , the diurnal change of surface of the tidal flat temperature is very extensive ; it reaches 37-39$^{\circ}C$ in August. At the depths of 5 and 10 cm the temperature remains at 33 $^{\circ}C$ and 31$^{\circ}C$ , respectively. 3. The chlorinity of the tidal flat is higher during May through June and lower July through August, and this seems to be related to the amount of rainfall. 4. The chlorinity of the surface of tidal flat increases slightly during the ebb and flow tide periods. The observed higher chlorinity of surface of the tidal flat was 18.82% Cl. 5. At near the esturay, the fresh water that overflows the tidal flat affects the chlorinity of the surface but no such influence to the depth of the flat. 6. From above observations, it is assumed that the young short necked clam in the tidal flat could be exposed to the severe change of environmental conditions. The high temperature of the tidal flat in summer and the low chlorinity of it at flood period may be considered as the change in environment.

  • PDF

Studies on the Natural Mortality of the Young Short Necked Clam, Tapes Japonica-II . Resistance to Temperature , Salinity and Exposure for the Young Short Necked Clam (바지락치패의 폐사에 관한 연구-II 바지락 치패의 온도, 염분, 노출에 대한 저항성)

  • CHOE, Sang
    • The Korean Journal of Zoology
    • /
    • v.9 no.1
    • /
    • pp.7-15
    • /
    • 1966
  • In a previous paper, the dirunal and monthly changes of the tidal flat temperature and chlorinity were observed. In this paper the resistance of the young short necked clam in various growth stages to the temperature, to the chlorinity and to the exposure were studies. The young clam used were in early (E), medium (M) and late (L) young stages whose shell lengths were 2.0-3.5mm, 9.0-11.0mm. and 14.0-16.0mm., respectively. The results were : 1. At various sea water temperatures , the chlorinity resistance of the young clam was directly proportional to the shell length. 2. When both inadequate sea water temperature and abnormal chlorinity are simultaneously applied, the resistance of these young clams was more markedly reduced than the case of applying either one of these conditions. 3. In clams of M and L, no lethal effect were observed when daily immersion of four to eight hours for a week into the sea water of any concentration of chloriity at 26-34$^{\circ}C$, whereas in E, 37-90% of mortalities were obtained by immersion of eight hours daily into both the fresh water and the sea water of higher chloriniites (more than 23.5$\textperthousand$ Cl) at the same temperature above. 4. The lower critical thermal maximum for lethal to the young clam was 38$^{\circ}C$. With four hours immersion daily at the water temperature of 38$^{\circ}C$, the mortalities of E, M and L to the lower chlorinities (less than 6.7$\textperthousand$Cl) were 100, 70-100 and 27-37% respectively ; to the higher chlorinities (more than 23.5$\textperthousand$Cl) 10-70, 10-37 and 3 % respectively ; to the normal range of chlorinities (13.4-16.8$\textperthousand$Cl) 0-13, 3 and 0 % respectively. 5. No lethal effects were observed in E and M clams immersed continuously for seven days in sea water with chlornities of 7.2 -21.7$\textperthousand$Cl at 18-24$^{\circ}C$, while notable mortalities were observed in E which had been kept at lower (less than 4.8$\textperthousand$ Cl) and higher (more than 24.1$\textperthousand$ Cl) chlorinites. 6. Although the resistance of the young clam to the chlorinity may have to be related closely to the life history of the clam prior subject to the experiment, the adapted chlorinity range was 7.2-19.3$\textperthousand$ Cl and the optimum range was 13.4-16.8$\textperthousand$Cl. 7. Remarkable lethal effects were observed for the E and M clams to the exposure temperature of 38$^{\circ}C$ whereas the L and had no such fatal results.

  • PDF

Projecting the Spatio-Temporal Change in Yield Potential of Kimchi Cabbage (Brassica campestris L. ssp. pekinensis) under Intentional Shift of Planting Date (정식일 이동에 따른 배추 잠재수량성의 시공간적 변화 전망)

  • Kim, Jin-Hee;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.18 no.4
    • /
    • pp.298-306
    • /
    • 2016
  • Planting date shift is one of the means of adapting to climate change in Kimchi Cabbage growers in major production areas in Korea. This study suggests a method to estimate the potential yield of Kimchi Cabbage based on daily temperature accumulation during the growth period from planting to maturity which is determined by a plant phenology model tuned to Kimchi Cabbage. The phenology model converts any changes in the thermal condition caused by the planting date shift into the heat unit accumulation during the growth period, which can be calculated from daily temperatures. The physiological maturity is estimated by applying this model to a variable development rate function depending either on growth or heading stage. The cabbage yield prediction model (Ahn et al., 2014) calculates the potential yield of summer cabbage by accumulating daily heat units for the growth period. We combined these two models and applied to the 1km resolution climate scenario (2000-2100) based on RCP8.5 for South Korea. Potential yields in the current normal year (2001-2010) and the future normal year (2011-2040, 2041-2070, and 2071-2100) were estimated for each grid cell with the planting dates of July 1, August 1, September 1, and October 1. Based on the results, we divided the whole South Korea into 810 watersheds, and devised a three - dimensional evaluation chart of the time - space - yield that enables the user to easily find the optimal planting date for a given watershed. This method is expected to be useful not only for exploring future new cultivation sites but also for developing cropping systems capable of adaptation to climate change without changing varieties in existing production areas.

An Experimental Study on Frost Heaving Pressure Characteristics of Frozen Soils (동결토의 동상팽창압 특성에 관한 실험적 연구)

  • 신은철;박정준
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.2
    • /
    • pp.65-74
    • /
    • 2003
  • Most of land reclamation projects are being implemented along the south and west coastal lines of the Korean Peninsula. The earth structures and in-ground LNG tank, and buildings can be constructed using artificial freezing method on the reclaimed land to control the uplift pressure caused by capillary forces. In this study, upon freezing a saturated soil in a closed-system from the top, a considerable frost heaving pressure was developed. Decomposed granite soils, silty soil, and sandy soil were used in the laboratory freeze test which is sometimes subjected to thermal gradients under closed-systems. A major concern has been the ability to predict the frost heaving pressure over the results of relatively short-term laboratory tests. The frost heaving pressure arising within the soil samples and the temperature of the samples inside were monitored with time elapse. The degree of saturation versus heaving pressure curve is presented for each soil sample and the maximum pressure is closely related to this curve. TDR apparatus was used to measure the volumetric water content by the measurement of unfrozen water contents of frozen soils. Unfrozen water increased in soils containing a high percentage of fine-grained particles. In fine-grained soils with strong attractive farces between soil grains and water molecules, additional water is attracted into the pores leading to further volume changes and ice segregation.