• Title/Summary/Keyword: Thermal effect

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Experimental Study on the Thermodynamic Characteristics of Commercial Small-size Moxa Combustion (상용 소형 쑥뜸의 열역학적 특성에 대한 실험적 연구)

  • Lee Geon-Mok;Hwang Yoo-Jin;Lee Gun-Hyee
    • Journal of Acupuncture Research
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    • v.18 no.6
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    • pp.171-187
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    • 2001
  • Objective : Moxibustion has been proved efficacious for many diseases, but isn't widespread in the clinics due to a danger of skin burning, the smoke produced while burning a moxa combustion and so on. Therefore, another type of moxa that can be resolved these troubles is required. To improve the effect of moxibustion and develop the new thermal stimulating treatment, the performance of commercial moxibustion widely used are studied systematically and found out quantitatively. Methods : We have selected two types (small-size moxa A(sMA), small-size moxa B (sMB)) among small-size moxaes used widely in the clinic. We examined combustion time, various temperatures, temperature gradient in each period during a combustion of moxa. Results : 1. The combustion time in the preheating period appeared somewhat longer in sMA than in sMB. 2, The combustion time in the heating period appeared longer in sMA by 26% than in sMB. 3. The average temperature in the heating period was $37.6{\sim}37.8^{\circ}C\;in\;sMA\;and\;36.2{\sim}36.8^{\circ}C$ in sMB and the maximum temperature measured at a center of contact surface in sMA was $48.6^{\circ}C$, higher by over $2.8^{\circ}C$ than that of sMB moxibustion. 4. The average ascending temperature gradient in the heating period was $0.08{\sim}0.1^{\circ}C/sec$ in both moxaes, and the average ascending temperature gradient of heating period in sMB appeared larger. The maximum ascending temperature gradient appeared higher in sMB, and the time reaching maximum ascending temperature gradient appeared much earlier in sMA than in sMB. 5. The combustion time in the retaining period was around 100 sec in sMA and around 275 sec in sMB. 6. The average temperature in the retaining period was $42.2{\sim}46.0^{\circ}C\;in\;sMA\;and\;39.3{\sim}41.4^{\circ}C/sec$ in sMB. The minimum temperature in the retaining period was over $38.80^{\circ}C$ in sMA but just $34.7^{\circ}C$ in sMB. 7. The average descending temperature gradient in sMA was $-0.050{\sim}0.067^{\circ}C/sec$ and in sMB was $-0.030{\sim}0.037^{\circ}C/sec$ 8. The combustion time in the cooling period appeared longer over two times in sMA than in sMB, and the time which the cooling period (minimum temperature) finished at appeared later in sMB by 55 sec. 9. We classified the combustion process that the measured temperature rose over body heat($37^{\circ}C$) into the effective combustion period. The effective combustion time was 233.3 sec in sMA and 300.4 sec in sMB respectively, and was longer by about 29% in sMB. The average temperature and maximum temperature in the effective combustion time appeared higher in sMA. The time taken until the maximum temperature was reached was 225.1 sec in sMA and 244.5 sec in sMB, faster by about 20 sec in sMA. The maximum ascending temperature gradient during the effective combustion period appeared larger about 1.4 times in sMB, but the time when the maximum ascending temperature gradient happened was faster in sMA. Conclusion : It appears that sMB, compared with sMA, is proper if necessary to apply the long time and weak stimulus, because of the gentle stimulus during the relatively longer time. In contrast, sMA that the symmetrical combustion happened is proper if necessary to apply the short time and strong stimulus.

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Effect of Hypothermia on the Prevention of Ventilator-Induced Lung Injury in Rats (백서에서 저체온 전처치가 환기기유발폐손상 억제에 미치는 효과)

  • Lim, Chae-Man;Hong, Sang-Bum;Koh, Youn-Suck;Shim, Tae-Sun;Lee, Sang-Do;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.5
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    • pp.540-548
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    • 2001
  • Backgrounds : Because ventilator-induced lung injury is partly dependent on the intensity of vascular flow, we hypothesized that hypothermia may attenuate the degree of such an injury through a reduced cardiac output. Methods : Twenty-seven male Sprague-Dawley rats were randomly assigned to normothermia ($37{\pm}1^{\circ}C$)-injurious ventilation (NT-V) group (n=10), hypothermia ($27{\pm}1^{\circ}C$)-injurious ventilation (HT-V) group (n=10), or nonventilated control group (n=7). The two thermal groups were subjected to injurious mechanical ventilation for 20 min with peak airway pressure 30 cm $H_2O$ at zero positive end-expiratory pressure, which was translated to tidal volume $54{\pm}6\;ml$ in the NT-V group and $53{\pm}4\;ml$ in the HT-V group (p>0.05). Results : Pressure-volume (P-V) curve after the injurious ventilation was almost identical to the baseline P-V curve in the HT-V group, whereas it was shifted rightward in the NT-V group. On gross inspection, the lungs of the HT-V group appeared smaller in size, and showed less hemorrhage especially at the dependent regions, than the lungs of the NT-V group. [Wet lung weight (g)/body weight (kg)] ($1.6{\pm}0.1$ vs $2.4{\pm}1.2$ ; p=0.014) and [wet lung weight/dry lung weight] ($5.0{\pm}0.1$ vs $6.1{\pm}0.8$ ; p=0.046) of the HT-V group were both lower than those of the NT-V group, while not different from those of the control group($1.4{\pm}0.4$, $4.8{\pm}0.4$, respectively). Protein concentration of the BAL fluid of the HT-V group was lower than that of the NT-V group($1,374{\pm}726\;ug/ml$ vs $3,471{\pm}1,985\;ug/ml$;p=0.003). Lactic dehydrogenase level of the BAL fluid of the HT-V group was lower than that of the NT-V group ($0.18{\pm}0.10\;unit/ml$ vs $0.43{\pm}0.22\;unit/ml$;p=0.046). Conclusions : Hypothermia attenuated pulmonary hemorrhage, permeability pulmonary edema, and alveolar cellular injuries associated with injurious mechanical ventilation, and preserved normal P-V characteristics of the lung in rats.

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Effect of Temperature on Development and Life Table Parameters of Tetranychus urticae Koch (Acari: Tetranychide) Reared on Eggplants (가지에서 온도별 점박이응애 발육특성 및 생명표 통계량)

  • Kim, Ju;Lee, Sang-Koo;Kim, Jeong-Man;Kwon, Young-Rip;Kim, Tae-Heung;Kim, Ji-Soo
    • Korean journal of applied entomology
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    • v.47 no.2
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    • pp.163-168
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    • 2008
  • Temperature dependent development of Tetranychus. urticae Koch was studied on the leaf of eggplant at 17, 22, 27, 32 and $37^{\circ}C$. T. urticae showed a minimum mortality at $27^{\circ}C$ and it increased at higher or lower temperatures than $27^{\circ}C$. The hatchability was low at 17 and $37^{\circ}C$. The duration of development decreased with increasing temperatures i.e., 5.3d at $37^{\circ}C$ and 25.8d at $17^{\circ}C$. Linear regression analysis of temperature vs. rate of development yielded the higher $r^2{\geq}0.88$ resulting in a good fit of the estimated line in the range of $17{\sim}37^{\circ}C$. Developmental zero temperature was $12.5^{\circ}C$ for the entire immature stage of female and $12.8^{\circ}C$ for that of male. Thermal constants were 80.5 and 74.7 degree days for those of female and male, respectively. Adult life span and oviposition period decreased with increasing temperatures. The number of eggs laid per female peaked at 141.0 eggs at $27^{\circ}C$, while that was a minimum 78.0 eggs at $37^{\circ}C$. Rate of hatchability, ratio of female, and $R_o$ were increased up to $27^{\circ}C$, and than declined thereafter. Intrinsic rate of natural increase (Rm) increased with rising temperatures and showed a maximum 0.5652 at $37^{\circ}C$. Also, ${\lambda}$ increased with increasing temperature. Doubling time (Dt) and generation time (T) decreased with increasing temperature.

Possibility of Soil Solarization in Korea (한국(韓國)에 있어서 태양열(太陽熱)을 이용(利用)한 토양소독(土壤消毒)의 가능성(可能性))

  • Ki, Kye-Un;Kim, Ki-Chung
    • Korean journal of applied entomology
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    • v.24 no.2 s.63
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    • pp.107-114
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    • 1985
  • This experiment was performed to see the possibility if soil-borne disease in green house can be controlled by soil solarization in Korea. Thermal death profiles of propagules of some soil-borne fungi, Fusarium oxysporum f. lycopersici, Fusarium oxysporum f. niveum, Rhizoctonia salani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Pythium debaryanum, were obtained under the conditions in water-suspension and in soil. Except Pythium debaryanum, all the fungal units in water-suspension that were colonized on barley grains lost a viability within 7 days in water bath at $45^{\circ}C$. When the soil in test tubes in which barley grains infected with the fungi were also buried all the fungi tested including Pythium debaryanum were completely killed within 7 days in water bath at $45^{\circ}C$. From July to August in Korea, soil temperature at depth of 5cm and 15cm within tunnel in plastic house reached $38^{\circ}C\;to\;57^{\circ}C$ and $40^{\circ}C\;to\;47^{\circ}\C$, in 1982 and 1983 respectively. Even at 15cm depth, soil temperature were kept over $43^{\circ}C$ for 12 hours a day. Adiabatic material set under ground or under mulching with the transparent polyethylene-film on the soil surface had a boostering effect for higher soil-temperature and longer duration. Fungi buried in adiabatic block of the soil in plastic house were completely killed at 15cm depth 14 days after, and at 20cm depth 21 days after soil solarization. The exposure of the pathogens to fluctuating temperature was much more effective than to constant. From the above results, soil-borne diseases may be effectively controlled by soil solarization in the closed plastic house in hot summer season in Korea.

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Gas Permeation Properties of Sulfonated 6FDA-Based Polyimide Membranes Exchanged with Metal Ions (금속이온이 치환된 설폰화된 6FDA계 폴리이미드 막의 기체 투과 특성)

  • Im, Hyeon-Soo;Lee, Byung-Seong;Lee, Bo-Sung;Yoon, Seok-Won;Koh, Hyung-Chul;Lee, Choong-Sub;Ha, Seong-Yong;Cheong, Seong-Ihl;Rhim, Ji-Won
    • Polymer(Korea)
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    • v.33 no.6
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    • pp.555-560
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    • 2009
  • Sulfonic acid of the sulfonated 6FDA-based polyimides were exchanged with the monovalent ($Li^+$, $Na^+$, $K^+$) and divalent ($Mg^{2+}$, $Ca^{2+}$, $Ba^{2+}$) ions. The effect of metal cations exchanged sulfonated polyimides was investigated in terms of gas permeability and selectivity for $CO_2$, $O_2$ and $N_2$ gases. Thermogravimetric analysis showed that thermal stability of sulfonated polyimide was improved by exchanged metal cations. The permeabilities of monovalent cation-exchanged, sulfonated polyimide were reduced as the ion radius reduced [$Li^+$(0.059 nm)>$Na^+$(0.102 nm)>$K^+$(0.138 nm)], and those of divalent cations exchanged were determined by the ionic radii and electrostatic crosslinking between the polymer and metal cations, whereas the selectivities of all the metal cation-exchanged, sulfonated polyimides for $CO_2/N_2$ and $O_2/N_2$, were higher than those of sulfonated polyimide membranes. The sulfonated polyimide exchanged with the potassium cation showed the $O_2$ permeability of 89.98 Barrer [$1\times10^{-10}\;cm^3$(STP) $cm/cm^2{\cdot}s{\cdot}cmHg$] and the sulfonated polyimide exchanged with the lithium cation showed the $O_2/N_2$ selectivity of 12.9.

Design of Thermo-optic Switch with Low Power Consumption by Electrode Optimization (전극 구조의 최적화를 통한 저전력 열광학 스위치 설계)

  • Choi, Chul-Hyun;Kong, Chang-Kyeng;Lee, Min-Woo;Sung, Jun-Ho;Lee, Seung-Gol;Park, Se-Geun;Lee, El-Hang;O, Beom-Hoan
    • Korean Journal of Optics and Photonics
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    • v.20 no.5
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    • pp.266-271
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    • 2009
  • We designed a thermo-optic switch based on a directional coupler with not only a high extinction ratio but also significantly low power consumption. The switch operates by using the thermo-optic effect of the polymer which the refractive index changes by heating the electrode. If the electrode is not powered (OFF), the input light will be coupled completely to the other waveguide. When the electrode is powered at a certain level (ON), input light launched into the input waveguide will remain in that waveguide due to the lower index adjusted in the other waveguide. The switch based on the directional coupler was designed using the generalized extinction ratio curve and the lateral shift of the input waveguide. The coupling length is 1,610 ${\mu}m$ and the extinction ratios are -28 and -30 dB for ON and OFF states, respectively. The electrode structures were optimized by thermal analysis. The transported heat into the waveguide is increased, as the electrode width (w) is increased and the center distance between the electrode and the waveguide (d) is decreased. Also, because the heat generated in the electrode affects the other waveguide, the temperature difference between two waveguides is varied as the given w and d. There are specific conditions which have the maximum of the temperature difference. That of the temperature difference is increased as the width and the temperature of the electrode are increased. Especially, when the switch is designed using the condition with the maximum of the temperature difference for switching, the temperature of the electrode can be decreased. We expect this condition will be the novel method for the reduction of the power consumption in a thermo-optic switch.

Effect of Leaf Aqueous Extracts from Some Gymnosperm Plant on the Seed Germination, Seedling Growth and Transplant of Hibiscus syriacus Varieties (수종 나자식물의 잎 수용 추출액이 무궁화의 품종별 종자발아와 유식물 및 초기생장에 미치는 영향)

  • 배병호;김용옥
    • The Korean Journal of Ecology
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    • v.26 no.1
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    • pp.39-47
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    • 2003
  • The leaf aqueous extracts from five gymnosperms plant were investigated for allelopathy with five Hibiscus syriacus varieties. The leaf aqueous extract of Pinus rigida had the highest total phenolic compound of 2.21mg/L, whereas the soil under Pinus koraiensis canopy had the highest total phenolic compound of 1.38mg/L. Fourteen phenolic compounds were isolated from five gymnosperm plants by HPLC. Among them, phenolic compounds were the highest in P. rigida (320.56 g/mg) with the primary compound 5-sulfosalicylic acid (312.55 g/mg). The correlation between leaf total phenolic compound and pH was not significant, while the total phenolic compound of the leaf extract changed soil pH. The relative seed germination of H. syriacus varieties showed 25% was threshold concentration. The germination rates of varieties were similar to the control group or showed slight stimulation to treatment of P. koraiensis extract. H. syriacus Cambanha was similar to the control group or showed stimulation in all treated groups. H. syriacus Seohohyang showed stimulation in both root and shoot growth compared to the control group. In other varieties except Seohohyang, shoot growth was similar to the control group, while root growth was stimulated in all treated groups. The extracts of tested gymnosperms showed significantly more stimulation to transplanted Seohohyang seedlings, whereas others were similar to control or inhibited in the greenhouse. The dry weight of Seohohyang was greater in all treated groups than the control group, while other varieties were inhibited. All gymnosperm extracts stimulated the chlorophyll contents of Seohohyang and H. syriacus Koyoro but other varieties were not significantly affected. Accordingly, it is suggested that Seohohyang seems the most desirable when planted within these five gymnosperms.

Geochemistry and Petrogenesis of Adakitic Granitoids from Bognae Area in the Southwestern Part of the Yeongnam Massif, Korea (영남육괴 남서부 복내지역에 분포하는 아다카이트질 화강암체의 성인 및 지화학적 특성)

  • Wee, Soo-Meen;Park, Jae-Yong
    • Journal of the Korean earth science society
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    • v.30 no.4
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    • pp.427-443
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    • 2009
  • Cretaceous intrusive and extrusive rocks in the southwestern part of the Yeongnam Massif are possibly the result of intensive magmatism which occurred in response to subduction of the Pacific plate beneath the northeast portion of the Eurasian plate. Geochemical and petrological study on the granitic rocks were carried out in order to constrain the petrogenesis of the granitic magma and to establish the paleotectonic environment of the area. Whole rock chemical data of the granitic rocks from the study area indicate that all the rocks have characteristics of calc-alkaline series in the subalkaline field. The overall geochemical features show systematic variations in each granitic body, but the source materials of each granitic body are thought to have been different in their chemical composition. The granodiorites distributed around Donggyori in the Bognae area (DGd) are different from other granitic rocks within the study area in the contents and differentiation trends of $Al_2O_3$ and MgO as well as in the contents of the trace elements such as Ba, Sr, Pb, Ni, Cr and Y DGd have geochemical features similar to slab-derived adakites such as high $Al_2O_3$, Sr contents and high Sr/Y, La/Yb ratios, but low Y and Yb contents. The major and trace element contents of the DGd fall well within the adakitic field, whereas other Cretaceous granites in the study area are plotted in the island arc ADR area in Sr/Y vs. Y diagram. On the ANK vs. A/CNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type and volcanic arc granite (VAG). Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of Pacific plate. The geochemical and tectonic features reveal that adakite-like signatures of the DGd were generated by the interaction of mantle peridotite and subducted slab-derived adakitic melts (caused by the thermal effect of ridge subduction), and which slightly modified by crustal contamination during emplacement.

Mock-up Test of Temperature Crack Reduction Method Application by Setting Time Control of Mat Foundation Mass Concrete (응결시간조정에 의한 매트기초 매스 콘크리트의 온도균열저감 공법적용의 Mock-up Test)

  • Han, Cheon-Goo;Lee, Jae-Sam;Noh, Sang-Kyun
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.55-61
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    • 2009
  • Recently, the number of high-rise buildings being built in Korea by major construction companies for residential and commercial use has been increasing. When constructing a high-rise building, it is necessary to apply massive amounts of concrete to form a mat foundation that can withstand the huge load of the upper structure. However, it is of increasing concern that due to limitations in terms of the amount of placing equipment, available job-sites and systems for mass concrete placement in the construction field, it is not always possible to place a great quantity of concrete simultaneously in a large-scale mat foundation, and for this reason consistency between placement lift cannot be secured. In addition, a mat foundation Is likely to crack due to the stress caused by differences inhydration heat generation time. To derive a solution for these problems, this study provides test results of a hydration heat crack reduction method by applying placement lift change and setting time control with a super retarding agent for mass concrete in a large-scale mat foundation. Mock-up specimens with different mixtures and placement liftswere prepared at the job-site of a newly-constructed high-rise building. The test results show that slump flow of concrete before and after adding the super retarding agent somewhat Increases as the target retarding time gets longer, while the air content shows no great difference. The setting time was observed to be retarded as the target retarding time gets longer. As the target retarding time gets longer, compressive strength appears to be decreased at an early stage, but as time goes by, compressive strength gets higher, and the compressive strength at 28 days becomes equal or higher to that of plain concrete without a super retarding agent. For the effect of placement lift change and super retarding agent on the reduction of hydration heat, the application of 2 and 4 placement lifts and a super retarding agent makes it possible to secure consistency and reduce temperature difference between placement lifts, while also extending the time to reach peak temperature. This implies that the possibility of thermal crack induced by hydration heat is reduced. The best results are shown in the case of applying 4 placement lifts.

Effect of Reaction Factors on the Properties of Complex Oxide Powder Produced by Spray Roasting Process (분무배소법에 의해 생성되는 복합산화물 분말들의 특성에 미치는 반응인자들의 영향)

  • 유재근;이성수;박희범;안주삼;남용현;손진군
    • Resources Recycling
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    • v.9 no.4
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    • pp.16-27
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    • 2000
  • In order to produce raw material powder of advanced magnetic material by spray roasting process, newly modified spray roasting system was developed in this work. In this spray roasting system, raw material solution was effectively atomized and sprayed into the reaction furnace. Also, uniform temperature distribution inside reaction furnace made thermal decomposition process fully completed, and produced powder was effectively collected in cyclone and bag filter. This system equipped with apparatus which can purify hazard produced gas. In this study complex acid solution was prepared by dissolution of mill scale and ferro-Mn into the acid solution, and the pH of this complex acid solution was controlled about to 4. It was conformed that mill scale and ferro-Mn containing a lot of impurities such as $SiO_2$, P and Al could be used as raw material by reducing the impurities content of complex acid solution below 20 ppm. Complex oxide powder of Fe-Mn system was produced by spraying purified complex acid solution into the spray roaster through nozzle, and the variations of produced powder characters were studied by changing he reaction conditions such as reaction temperature, the injection velocity of solution and air, nozzle tip size and concentration of solution. The morphology of produced powder had spherical shape under the most experimental conditions, and concentration of solution. The morphology of produced powder has spherical shape under the most experimental conditions, and the composition and the particle size distribution were almost uniform, which tells the excellence of this spray roasting system. The grain size of most produced powder was below 100 nm. From the above results, it will be possible to produce ultra fine oxide powder from the chloride of Fe, Mn, Ni, Cu and rare earth by using this spray roasting system, and also to produce ultra fine pure metal powder by changing reaction atmosphere.

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