• Title/Summary/Keyword: Release Times

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A Study on the Heat Release Rate of EPS Sandwich Panel Core (EPS 샌드위치 패널 심재의 열방출율에 관한 연구)

  • Park, Hyung-Ju;Cho, Myung-Ho
    • Fire Science and Engineering
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    • v.22 no.5
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    • pp.72-78
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    • 2008
  • The mass loss rate and heat release rate of EPS sandwich panel cores were analysed using variable external irradiation level. The experimental materials were exposed to incident heat fluxes form 20 to 50 kW/$m^2$. For the measurement of mass loss rate and heat release rate, the size of specimen was $100mm{\times}100mm{\times}50mm$ and the samples were 3 different kinds. The combustion heat were carried out from the Oxygen bomb calorimeter and the mass loss rate and heat release rate were carried out from the Mass loss calorimeter according to ISO 5660-1. As the results of this study, the mass loss rate of Type A, B, and C were 2.7 g/$m^2s$, 2.8 g/$m^2s$, and 2.3 g/$m^2s$ and the heat release rate of Type A, B, and C were 58.23 kW/$m^2$, 47.19 kW/$m^2$, and 50.06 kW/$m^2$ respectively at the heat flux of 50 kW/$m^2$. In conclusion, when the heat release characteristics applied to a classification system of Canada, Type A and C can be classified grade C-3, and Type C can be classified grade C-2 from all data of this study.

EFFECTS OF PANAX GINSENG SAPONINS ON CHEMICAL MEDIATOR RELEASE FROM AIRWAY SMOOTH MUSCLE IN ACTIVELY SENSITIZED GUINEA PIG

  • Ro Jai Youl;Yoon Suk Jong;Lee Jong Wha;Kim Kyung Hwan
    • Proceedings of the Ginseng society Conference
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    • 1993.09a
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    • pp.84-93
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    • 1993
  • It has been reported that ginseng is effective in the central nervous system, immune system, and the strong inflammatory responses. However, there has been no research report yet about the effect of ginseng on allergic hypersensitivity reactivity. To confirm the ginseng effects on the release of mediators(histamine. leukotrienes etc.) which cause the hypersensitivity reactivity and inflammatory response, we used actively sensitized guinea pig airway tissues by utilizing the superfusion technique. In this procedure. the contractile response and mediators released after antigen stimulation of sensitized tissues, and IgG and IgE antibody products were measured in sera of immunized animals. Then the results of the controll group were compared to those of ginseng pretreatment groups. In the total saponin(TS) and panaxatriol(PT) pretreatment, histamine release decreased by $20\%$ in the tracheal tissues after active sensitization by ovalbumin(OVA, 10mg/kg), but in the lung parenchyma, histamine release decreased by $40\%.$ Panaxadiol(PD) significantly decreased histamine release by $40\%$ in the both tissues after active sensitization. TS, PT and PD of ginseng poorly blocked leukotrienes (LTs) and prostagrandin $D_2(PGD_2)$ release(less than $10\%$). Ginseng TS and PT had no effect on the serum IgG antibody production by ovalbumin, whereas PD significantly increased serum IgG antibody contents(approximately by 2 times). However, $IgG_1$ antibody products in the serum of guinea pig actively sensitized with ovalbumin after PD pretreatment were decreased, compared to that with ovalbumin alone. IgE antibody production by passive cutaneous anaphylaxis(PCA) titer in the TS pretreatment increased 3 times more than in the absence of TS(PCA titer by PT was not detected). These studies show that some ginseng saponins can in part act to inhibit mediator release in antigen - induced airway smooth muscle by inducing the IgG antibody production which has been changed in the specificity.

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Influence of $\omega$-Conotoxin GVIA, Nifedipine and Cilnidipine on Catecholamine Release in the Rat Adrenal Medulla

  • Yu, Byung-Sik;Kim, Byeong-Cheol;Lim, Dong-Yoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.11 no.1
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    • pp.21-30
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    • 2007
  • The present study was designed to establish comparatively the inhibitory effects of cilnidipine(CNP), nifedipine(NIF), and $\omega$-conotoxin GVIA(CTX) on the release of CA evoked by cholinergic stimulation and membrane depolarization from the isolated perfused model of the rat adrenal medulla. CNP(3 ${\mu}M$), NIF(3 ${\mu}M$), and CTX(3 ${\mu}M$) perfused into an adrenal vein for 60 min produced greatly inhibition in CA secretory responses evoked by ACh($5.32{\times}10^{-3}M$), DMPP($10^{-4}M$ for 2 min), McN-A-343($10^{-4}M$ for 2 min), high $K^+(5.6{\times}10^{-2}M)$, Bay-K-8644($10^{-5}M$), and cyclopiazonic acid($10^{-5}M$), respectively. For the CA release evoked by ACh and Bay-K-8644, the following rank order of potency was obtained: CNP>NIF>CTX. The rank order for the CA release evoked by McN-A-343 and cyclopiazonic acid was CNP>NIF>CTX. Also, the rank orders for high $K^+$ and for DMPP were NIF>CTX>CNP and NIF>CNP>CTX, respectively. Taken together, these results demonstrate that all voltage-dependent $Ca^{2+}$ channels(VDCCs) blockers of cilnidipine, nifedipine, and $\omega$-conotoxin GVIA inhibit greatly the CA release evoked by stimulation of cholinergic(both nicotinic and muscarinic) receptors and the membrane depolarization without affecting the basal release from the isolated perfused rat adrenal gland. It seems likely that the inhibitory effects of cilnidipine, nifedipine, and $\omega$-conotoxin GVIA are mediated by the blockade of both L- and N-type, L-type only, and N-type only VDCCs located on the rat adrenomedullary chromaffin cells, respectively, which are relevant to $Ca^{2+}$ mobilization. It is also suggested that N-type VDCCs play an important role in the rat adrenomedullary CA secretion, in addition to L-type VDCCs.

Ethylene Release of Panax ginseng in Relation to Plant Part and Various Conditions (고려인삼의 식물부위 및 여러 조건과 관련한 에틸렌가스 방출)

  • Park, Hoon;Lee, Myong-Gu;Lee, Chong-Wha
    • Journal of Ginseng Research
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    • v.14 no.2
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    • pp.122-125
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    • 1990
  • Ethylene was released from leaf and fruit but root of Panax ginseng. Root callus showed higher ethylene release (ER) than fruit ER increased with leaf senesence. Fruit during ripening showed decreasing ER in the order of green stage, early stage of reddening and fully ripened stage. between leaves from the plant with fruits in different stages of ripening showed similar trend of fruit in ER but it was about 10 times higher in leaves than in fruits. Leaves of P. quinquefolius showed about 200 times higher ER than that of P ginseng on 22 July Fruits from the plant treated with ethephon showed higher ER after 109 days. Forty-five day-old seedlings grown with various growth regulators showed a significant decrease of stem length and significant increase of ER only in Uniconazole (0.1 ppm) and H-9 (0.0, 5 ppm) solution.

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Preparation of Albumin Microcapsule Containing Beads and Sulfamethoxydiazine by Simple Coacervation (Simple Coacervation에 의한 Beads 및 Sulfamethoxydiazine의 Albumin Microcapsule의 조제에 관한 연구)

  • 구영순;김신옥
    • YAKHAK HOEJI
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    • v.31 no.3
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    • pp.182-188
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    • 1987
  • Simple coacervation of bovine serum albumin was studied to prepare biodegradable microacapsule. Albumin microcapsules were prepared by using acrylonitrilestyrene polymer (M-80) resin beads and sulfamethoxydiazine as the core materials. The albumin to beads ratio was found to be 1:2.3 and the albumin to sulfamethoxydiazine ratio to be 1:2.9. The 50% release times (T$_{50%}$) of sulfamethoxydiazine and microencapsulated sulfamethoxydiazine were 6 min. and 73 min., respectively. The surface appearance of the microcapsule collected after release experiment was not different from those of the original microcapsule. In addition to slowing release of drug the microencapsulation process masked characteristic bitter taste of sulfamethoxydiazine.

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The Study on Compartment Fire Experiment According to Fire Load (화재하중에 따른 구획화재 실험 연구)

  • Kweon, Oh-Sang;Kim, Heung-Youl
    • Fire Science and Engineering
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    • v.31 no.6
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    • pp.16-22
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    • 2017
  • In Korea, performance-based fire safety designs are being discussed to deal with the various risks of fire in complex and diverse types of structure. However, performance-based fire safety designs are not actively employed because it is difficult to estimate the fire characteristics related to the various factors in buildings. In this study, real scale fire tests were conducted based on fire severity levels and fire loads provided in He New Zealand Building Code, in order to use the results as guidelines and fundamental data for performance-based designs. In the real scale fire tests conducted in a 10MW full-scale calorimeter, wood cribs were placed in a $2.4(L){\times}3.6(W){\times}2.4(H)m$ mock-up of a compartment which had one $0.8(L){\times}2.0(H)$ opening for different fire loads and heating was continued until all of the wood cribs were burned down. The heat release rate started to increase rapidly 90 seconds after the wood cribs caught fire. In the test with a fire load level 1, the maximum heat release rate of 4743.4 kW was reached at 244 second. In the test with fire load level 2, a maximum heat release rate of 5050.9 kW was reached at 497 second. In the test with fire load level 3, a maximum heat release rate of 4446.9 kW was reached at 677 second.

Release Profile and Antimicrobial Activity of Nisin Control-released from Agar Gel Foods

  • Zong, Yicheng;Han, Jung Hoon;Oh, Yeong Ji;Min, Sea C.
    • Food Engineering Progress
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    • v.21 no.1
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    • pp.36-41
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    • 2017
  • The release profiles of nisin from nisin-incorporating gel foods and the antimicrobial activities of the gels on the growth of Brochothrix thermosphacta in an aqueous system containing the gels have been investigated. A linear regression model was applied to determine the diffusion coefficient (D) for the diffusion of nisin in the gel. The antimicrobial activities of nisin released from 1, 2 and 3% (w/v) agar gels on the growth of B. thermosphacta in a broth medium with and without nisin were investigated. The D decreased from $1.2{\times}10^{-2}$ to $8.2{\times}10^{-3}$ and $6.4{\times}10^{-3}cm^2/s$ as the agar concentration in the gel increased from 1 to 2 and 3% (w/v), demonstrating the diffusion rate in the gels can be controlled by the agar concentration in gel. The agar gel incorporating nisin inhibited the B. thermosphacta growth in the broth medium by prolonging the lag phase. The growth inhibition was enhanced by the addition of nisin in the medium. The results of this study exhibited that the gel food is a feasible nisin delivery system with a controlled release achieved by the adjustment of agar concentration in the system, demonstrating the potential of nisin-incorporating gel for preserving particulate-containing drinks.

The Optimal Release Time in Cost Model Using PCLS Model

  • Song, Kwang Yoon;Chang, In Hong;Choi, Min Su;Lee, Da Hye
    • Journal of Integrative Natural Science
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    • v.9 no.3
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    • pp.206-214
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    • 2016
  • The basic goal of software development is to produce high quality software at low cost. Therefore, when to stop software testing and release the software product is a significant point in the software development. The software cost model is an effective tool used to help software developers control costs and determine the release time. In this paper, we discuss the cost model to apply all 6 models with consideration of time to remove errors, cost of removing each error and risk cost due to software failure. We show the impact of cost coefficients and parameter values on the expected total cost by changing the values and comparing the optimal release times.

Microplastic release from damaged commercial teabags

  • Kim, Sion;Jo, Eun Ha;Choi, Soohoon
    • Membrane and Water Treatment
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    • v.13 no.1
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    • pp.21-28
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    • 2022
  • The use of plastics in our everyday lives have been drastically increased during the last few decades. However with the usage of commercial plastic products there is a possibility of microplastic consumption, due to the fragmentation of the products. Additionally, the potential for microplastic ingestion may also be increased by using damaged products. Hence, the current study was conducted to understand the potential release of micro/nano plastics and organic matter from damaged teabags. To check the leakage tendency, the amount of damage to the tea bags from 1-10 cm were tested along with temperatures of 25-70℃, and exposure times from 5 min to 1 hr was tested. Release of fibrous micro/nanoplastics, and organic leachate from the damaged teabags were observed to understand the outflow conditions. Results showed that with the increased degree of damage, temperature, and exposure time increased the release of fiberous matter, where the increase of temperature, and exposure time increased organic leachate. Additional analysis confirmed the leachate of nylon polymers into the heated water.

Laplace Transforms of First Exit Times for Compound Poisson Dams

  • Lee, Ji-Yeon
    • 한국데이터정보과학회:학술대회논문집
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    • 2005.10a
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    • pp.171-176
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    • 2005
  • An infinite dam with compound Poisson inputs and a state-dependent release rate is considered. We build the Kolmogorov's backward differential equation and solve it to obtain the Laplace transforms of the first exit times for this dam.

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