• 제목/요약/키워드: Heat Stable

검색결과 1,281건 처리시간 0.029초

가스수화물 BSR을 이용한 남극반도 남쉐틀랜드 대륙주변부의 지열류량 변화 (Gas Hydrate BSR-derived Heat Flow Variations on the South Shetland Continental Margin, Antarctic Peninsula)

  • 진영근;남상헌;김예동;김규중;이주한
    • Ocean and Polar Research
    • /
    • 제25권2호
    • /
    • pp.201-211
    • /
    • 2003
  • Bottom simulating reflectors (BSR), representing the base of the gas hydrate stability field, are widespread on the South Shetland continental margin (SSM), Antarctic Peninsula. With the phase diagram fur the gas hydrate stability field, heat flow can be derived from the BSR depth beneath the seafloor determined on multichannel seismic profiles. The heat flow values in the study area range from $50mW/m^2$ to $85mW/m^2$, averaging to $65mW/m^2$. Small deviation from the average heat flow values suggests that heat flow regime of the study area is relatively stable. The landward decrease of heat flow from the South Shetland Trench to the continental shelf would be attributed to the landward thickening of the accretionary prism and the upward advection of heat associated with fluid expulsion. The continental slope 1500m to 3000m deep, where BSRs are most distinguished in the SSM, shows relatively large variation of heat flow possibly due to complex tectonic activities in the study area. The local high heat flow anomalies observed along the slope may be caused by heat transport mechanisms along a NW-SE trending large-scale fault.

Enhanced Virus Safety of a Solvent/Detergent-Treated Anti-hemophilic Factor IX Concentrate by Dry-Heat Treatment

  • Shin Jeong-Sup;Choi Yong-Woon;Sung Hark-Mo;Ryu Yeon-Woo;Kim In-Seop
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • 제11권1호
    • /
    • pp.19-25
    • /
    • 2006
  • With particular regards to the hepatitis A virus (HAV), a terminal dry-heat treatment ($100^{\circ}C$ for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor IX concentrate. The loss of factor IX activity during dry-heat treatment was of about 3%, as estimated by a clotting assay. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor IX compared with those of the factor IX before dry-heat treatment. The dry-heat-treated factor IX was stable for up to 24 months at $4^{\circ}C$, The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV and murine encephalomyocarditis virus (EMCV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Porcine parvovirus (PPV) and bovine herpes virus (BHV) were potentially sensitive to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were ${\ge}5.60$ for HAV, ${\ge}6.08$ for EMCV, 2.64 for PPV, and 3.59 for BHV. These results indicate that dry-heat treatment improves the virus safety of factor IX concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

Dry-Heat Treatment Process for Enhancing Viral Safety of an Antihemophilic Factor VIII Concentrate Prepared from Human Plasma

  • Kim, In-Seop;Choi, Yong-Woon;Kang, Yong;Sung, Hark-Mo;Shin, Jeong-Sup
    • Journal of Microbiology and Biotechnology
    • /
    • 제18권5호
    • /
    • pp.997-1003
    • /
    • 2008
  • Viral safety is a prerequisite for manufacturing clinical antihemophilic factor VIII concentrates from human plasma. With particular regard to the hepatitis A virus (HAV), a terminal dry-heat treatment ($100^{\circ}C$ for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor VIII concentrate. The loss of factor VIII activity during dry-heat treatment was of about 5%. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor VIII compared with those of the factor VIII before dry-heat treatment. The dry-heat-treated factor VIII was stable for up to 24 months at $4^{\circ}C$. The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV, murine encephalomyocarditis virus (EMCV), and human immunodeficiency virus (HIV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Bovine herpes virus (BHV) and bovine viral diarrhea virus (BVDV) were potentially sensitive to the treatment. However porcine parvovirus (PPV) was slightly resistant to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were ${\geq}5.55$ for HAV, ${\geq}5.87$ for EMCV, ${\geq}5.15$ for HIV, 6.13 for BHV, 4.46 for BVDV, and 1.90 for PPV. These results indicate that dry-heat treatment improves the virus safety of factor VIII concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid-enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

Stimulation of Dendritic Cell Maturation and Induction of Apoptosis in Leukemia Cells by a Heat-stable Extract from Azuki bean (Vigna angularis), a Promising Immunopotentiating Food and Dietary Supplement for Cancer Prevention

  • Nakaya, Kazuyasu;Nabata, Yuri;Ichiyanagi, Takashi;An, Wei Wei
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제13권2호
    • /
    • pp.607-611
    • /
    • 2012
  • Non-toxic stimulation of dendritic cells (DCs), which are central immunomodulators, may aid the prevention of cancer. Furthermore, induction of apoptosis in cancer cells by anticancer agents contributes to the induction of DC maturation. We previously reported that extracts from $Pinus$ $parviflora$ Sieb. et Zucc pine cone and $Mucuna$ seed induce differentiation of mouse bone marrow cells into mature dendritic cells and also induce apoptosis in various human cancer cell lines. In the present study, we screened 31 kinds of edible beans with biological activity similar to that of extracts from pine cone and $Mucuna$ and found that the heat-stable extract from azuki bean ($Vigna$ $angula$) stimulated differentiation of bone marrow cells into immature DCs with the greatest efficacy. The level of IL-6 produced by sequential treatment of DCs with azuki extract and lipopolysaccharide was the highest among the examined beans. Azuki extract also inhibited the growth of human leukemia U937 cells, leading to induction of apoptosis. These results suggest that azuki bean and its extract are immunopotentiating foods that can be used as a dietary supplement for cancer prevention and immunotherapy.

Investigation of allowable time-step sizes for generalized finite element analysis of the transient heat equation

  • O'Hara, P.;Duarte, C.A.;Eason, T.
    • Interaction and multiscale mechanics
    • /
    • 제3권3호
    • /
    • pp.235-255
    • /
    • 2010
  • This paper investigates the heat equation for domains subjected to an internal source with a sharp spatial gradient. The solution is first approximated using linear finite elements, and sufficiently small time-step sizes to yield stable simulations. The main area of interest is then in the ability to approximate the solution using Generalized Finite Elements, and again explore the time-step limitations required for stable simulations. Both high order elements, as well as elements with special enrichments are used to generate solutions. When compared to linear finite elements, the high order elements deliver better accuracy at a given level of mesh refinement, but do not offer an increase in critical time-step size. When special enrichment functions are used, the solution can be approximated accurately on very coarse meshes, while yielding solutions which are both accurate and computationally efficient. The major conclusion of interest is that the significantly larger element size yields larger allowable time-step sizes while still maintaining stability of the time-stepping algorithm.

Mg-Zn-(Zr) 합금의 미세조직과 결정립의 안정성 (Microstructures and Grain Stabilities of Mg-Zn-(Zr) Alloys)

  • 전중환
    • 열처리공학회지
    • /
    • 제23권6호
    • /
    • pp.309-314
    • /
    • 2010
  • Microstructures and grain growth behaviors at elevated temperatures have been investigated for extruded Mg-2%Zn and Mg-2%Zn-0.3%Zr alloys, in order to clarify the role of Zr in grain stability of Mg-Zn alloy. The grain size of Zr-free alloy increased continuously with an increase in annealing temperature, when isochronally annealed for 60 min from 573 to 723K, while the grains of the Zr-containing alloy were relatively stable up to 723 K. The activation energies for grain growth ($E_g$) between 573 and 723 K were calculated as 77.8 and 118.6 kJ/mole for the Mg-2%Zn and Mg-2%Zn-0.3%Zr alloys, respectively, which indicates that grains in the Zr-added alloy possess higher thermal stabilities at elevated temperatures. TEM observations on the annealed Mg-2%Zn and Mg-2%Zn-0.3%Zr alloys revealed that enhanced grain stability resulting from Zr addition into Mg-Zn alloy would be ascribed to the restriction of grain growth by stable Zn-Zr nano-precipitates distributed in the microstructure.

준밀폐형 2상자연순환 회로 내에서의 유동 진동에 관한 실험적 연구 (Experimental Investigation of Flow Oscillations in a Semi-closed Two-phase Natural Circulation Loop)

  • 김종문;이상용
    • 대한기계학회논문집B
    • /
    • 제22권12호
    • /
    • pp.1763-1773
    • /
    • 1998
  • In the present experimental study, the flow behavior in a semi-closed two-phase natural circulation loop was examined. Water was used as the working fluid. Heat flux, heater-inlet subcooling, and flow restrictions at the heater-inlet and at the expansion-tank-line were taken as the controlling parameters Six circulation modes were identified by changing heat flux and inlet subcooling conditions ; single-phase continuous circulation, periodic circulation (A), two-phase continuous circulation, and periodic circulations (B), (C), and (D). Among these, the single-phase and two-phase continuous-circulation modes exhibit no significant oscillations and are considered to be stable. Periodic circulation (A) is characterized by the large amplitude two-phase f10w oscillations with the temporal single-phase circulation between them, while periodic circulation (B) featured by the flow oscillations with continuous boiling inside the heater section. Periodic circulation (C) appears to be the manometric oscillation with continuous boiling. Periodic circulation (D) has the longer period than periodic circulation (B) and a substantial amount of liquid flow back and forth through the expansion-tank-line periodically ; this mode is considered the pressure drop oscillation. Parametric study shows that the increases of the inlet- and expansion-tank-line- restrictions and the decrease of inlet subcooling broaden the range of the stable two-phase(continuous circulation) mode.

Heat stress protection in Aspen sp1 transgenic Arabidopsis thaliana

  • Zhu, Bo;Xiong, Ai-Sheng;Peng, Ri-He;Xu, Jing;Zhou, Jun;Xu, Jin-Tao;Jin, Xiao-Fen;Zhang, Yang;Hou, Xi-Lin;Yao, Quan-Hong
    • BMB Reports
    • /
    • 제41권5호
    • /
    • pp.382-387
    • /
    • 2008
  • It is known that the stable protein 1 (SP1) detected in aspen plants remains soluble upon boiling and that sp1 expression in transgenic aspen is resistant to salt stress. Presently, we analyzed the effect of expression of SP1 in Arabidopsis thaliana plants and their response to high temperature stress. After $45^{\circ}C$ for 16 h, relative to wild type plants, sp1 transgenic plants exhibited stronger growth and were better in several physiological properties including chlorophyII, chlorophyII fluorescence, water content, proline content, and malondialdehyde content. These preliminarily results suggest that the over-expression of SP1 may notably enhance heat-tolerant level of transgenic A. thaliana plants.

미생물(微生物)이 생산(生産)하는 응유효소(凝乳酵素) (제10보(第10報)) -Mucor-pusillus의 고체배양(固體培養)으로부터 단리(單離)된 결정(結晶) 응유효소(凝乳酵素) Mucor-rennin의 일반적(一般的) 성질(性質)과 그의 저장성(貯藏性)- (Milk-clotting Enzyme from Microorganisms, Part 10, Studies on General Properties and storage of Mucor-rennin (Milk-clotting Enzyme) isolated from Mucor pusillus var. Lindt)

  • 유주현;전촌학조;홍윤명;유마계
    • Applied Biological Chemistry
    • /
    • 제12권
    • /
    • pp.7-11
    • /
    • 1969
  • Mucor-rennin, the crystalline milk-clotting enzyme, isolated from Mucor pusillus var. Lindt, has an acid protease activity. The optimum pH for the digestion of k-casein is 4.5, while that for hemoglobin digestion is 4.0. The skim milk solution was easily clotted acidic solution than alkalin solution, and the milk clotting activated by Ca ion. The enzyme was heat stable against heat from pH 4.0 to 6.0 but was more stable at pH 5.0. The activity of the enzyme at pH 5.0 did not decrease at 30 C for 15 days and the activity was not effected by sodium propionate and salicilic acid. Therefore, the enzyme of liguid type could store for a long time and could be transported from Erzyme production Co. to Manufacture of cheese Co. by adding the antiesptic and by adjusting pH to 5.0.

  • PDF

생물학적 처리방법에 의한 경남산 단감의 저장성 향상을 위한 기술개발 (evelopment of biological methods for improving the storage qualities of sweet persimmon harvested in Gyeongsangnam-do)

  • 조성환;김영록
    • 한국식품위생안전성학회지
    • /
    • 제10권4호
    • /
    • pp.263-270
    • /
    • 1995
  • In order to promote the prevention of microbial and enzymatic spoilage and to retain the freshiness, sweet persimmons harvested in Gyeongsangnam-do were treated with graperfruit seed extract(GFSE)-CaCO3 mixture and stored in the proper packaging conditions. A low concentration of GFSE showed effective growth inhibition of plant pathological bacteria and fungi, Enterobacter pyrinus and Fusarium sp., which were involved in the decay of fruits and vegetables. GFSE was stable to heat treatment; its antimicrobial activity was not changed by heat treatment upto 10$0^{\circ}C$. However, when the temperature was raised to 12$0^{\circ}C$, about 90% of total activity was retained within 30 min. GFSE was also highly stable to broad pH changes; its activity was not changed in the range of pH 2.0 to pH 12.0. The physiological function of cell membrane in the spores of Bacillus cereus and the hyphae of Fusarium sp. was destroyed by treating with GFSE. It was observed that treating sweet persimmons with GFSE minxture and storing them in strech-wrapped packages could prolong the greshness of sweet persimmons and reduce quality deterioration.

  • PDF