• Title/Summary/Keyword: temperature-sensitive

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The study on controling curie temperature for the temperature-sensitive Magnetic materical at colling method. (냉각방법에 의한 감온자성체의 큐리온도 조정에 관한 연구)

  • Bae, Jin-Ho;Sin, Yong-Cheol;Kim, Han-Geun
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.828-830
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    • 1988
  • This paper considered temperature-sensitive characteristics on the basis of curie tempeature and quenching method in the process of manufacturing Mn-Cu-Zn Fersite. The results are as follow. Curie tempeature drops according as the content of CuO and ZnO increases. It also decreases according as sintering temperature increases when the content of ZnO in fixed. Curie temperature drops more in quenching than in slow cooling and activation energy diminishes were too. On the basis of curie tempeature, activation energy is greater in paramagnetic region than in ferrimagnetic region. As its voltage-crrent characteristics is similar to that semiconductors, the temperature-sensitive ferrite is expeated to be appied in the area of power electronics.

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pH- and Temperature-Sensitive Bifunctional Hydrogels of N-Isopropylacrylamide and Sulfadimethoxine Monomer

  • Lee, Jin-Woo;Lee, Doo-Sung;Kim, Sung-Wan
    • Macromolecular Research
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    • v.11 no.3
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    • pp.189-193
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    • 2003
  • pH- and temperature-sensitive bifunctional hydrogels composed of N-isopropylacrylamide (NiPAAm) and a sulfadimethoxine monomer (SDM) derived from sulfadimethoxine were prepared. These hydrogels exhibit simultaneous pH- and temperature-induced volume-phase transitions. The pH-induced volume-phase transition behavior is produced by the ionization/deionization of SDM and is very sharp. In the high pH region, the ionization of SDM induces swelling of the hydrogels. In the low pH region, the deionization of SDM induces deswelling of the hydrogels. The temperature-induced volume-phase transition behavior of the bifunctional hydrogels exhibits negative thermosensitivity because of the NiPAAm component. The hydrogels swell even at low pH as the temperature decreases. The hydrogels swell at low temperature and high pH, and deswell at high temperature and low pH. The volume of the hydrogels dependl on the balance of the swelling and deswelling produced by the two competing stimuli, pH and temperature.

Construction of a Temperature Controlled Expression Ve e tor in Saccharumy ces cerevisiae (Saccharomyces cerevisiae를 이용한 온도조절형 발현 Vector의 개발)

  • 최진옥;황용일
    • Microbiology and Biotechnology Letters
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    • v.21 no.3
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    • pp.214-220
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    • 1993
  • The mating type a of yeast, Saccharomyces cerevisiae mutant with hmla2-102 and sir3-8ts was changed to type alpha by changing the growth temperature from 25C to 35C. A temperature-sensitive expression vector system was constructed using mating factor alpha1 (Mfalpha1) gene encoding alpha factor which is expressed in the type alpha cells. Vectors with different copy numbers were constructed by joining the promoter and pre or prepro-secretion single sequence of Mfalpha1 to promoterless PHO5' gene as a reporter gene.

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Climatic and Environmental Effects on Distribution of Narrow Range Plants (국지적으로 분포하는 식물에 대한 기후 및 환경변수 영향)

  • Kwon, Hyuksoo;Ryu, Jieun;Seo, Changwan;Kim, Jiyeon;Tho, Jaehwa;Suh, Minhwan;Park, Chonghwa
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.6
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    • pp.17-27
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    • 2012
  • Climate is generally accepted as one of the major determinants of plants distribution. Plants are sensitive to bioclimates, and local variations of climate determine habitats of plants. The purpose of this paper is to identify the factors affecting the distribution of narrow-range plants in South Korea using National Survey of Natural Environment data. We developed species distribution models for 6 plant species using climate, topographic and soil factors. All 6 plants were most sensitive to climatic factors but less other factors at national scale. Meliosma myriantha, Stewartia koreana and Eurya japonica, distributed at southern and coast region in Korea, were most sensitive to precipitation and temperature. Meliosma myriantha was mostly effected by annual precipitation and precipitation of driest quarter, Stewartia koreana was effected by annual precipitation and elevation, and Eurya japonica was affected by temperature seasonality and precipitation of driest quarter. On the other hand, Spiraea salicifolia, Rhododendron micranthum and Acer tegmentosum, distributed at central and northern inland in Korea, were most sensitive to temperature and elevation. Spiraea salicifolia was affected by mean temperature of coldest quarter and annual mean temperature, Rhododendron micranthum and Acer tegmentosum were affected by mean temperature of warmest quarter and elevation. We can apply this result to future plant habitat distribution under climate change.

Release of Calcein from Temperature-Sensitive Liposomes in a Poly(N-isopropylacrylamide) Hydrogel

  • Han Hee Dong;Kim Tae Woo;Shin Byung Cheol;Choi Ho Suk
    • Macromolecular Research
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    • v.13 no.1
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    • pp.54-61
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    • 2005
  • We prepared temperature-sensitive liposomes (TS-liposomes) modified with a thermo sensitive polymer, such as poly(N-isopropylacrylamide) (PNIPAAm), to increase the degree of drug release from liposomes at the hyperthermic temperature. A PNIPAAm hydrogel containing TS-Iiposomes was also prepared to obtain a hydrogel complex at body temperature. In addition, a depot system for local drug delivery using the polymer hydrogel was developed to enhance therapeutic efficacy and prevent severe side effects in the whole body. The PNIPAAm-mod­ified TS-liposome was fixed into the PNIPAAm hydrogel having a high temperature-sensitivity. The release behavior of calcein, a model drug, from TS-liposomes in the PNIPAAm hydrogel was then initiated by external hyperthermia; the results indicated that sustained release as a function of temperature and time was caused by the thermosensitivity of the liposome surface and diffusion of the drug into the PNIPAAm hydrogel. Our results indicated that TS-liposomes in a PNIPAAm hydrogel represented a plausible system for local drug delivery.

Isolation and Analysis of Temperature Sensitive Mutants in Aspergillus nidulans (Aspergillus nidulans 온도감수성 돌연변이주의 분리 및 분석)

  • 박찬규;강현삼
    • Korean Journal of Microbiology
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    • v.16 no.3
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    • pp.111-121
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    • 1978
  • About 40 temperature-sensitive mutants have been isolated as a preliminary step to study the spore germination, the cell cycle, and the control of macromolecular synthesis in Aspergillus nidulans. To obtain temperature-sensitive mutants rapidly and effectively, the selective enrichment method using antifungal antibiotic nystatin was developed. Based on the data which had applied to the concentration of auxotrophic mutants by the earlier investigators, the optimal concentration and the time of treatment at the nonpermissive temeprature were determined as 50 to 100 units per ml and 4.5 hr., respectively. Out of 41 ts mutants assigned to the strain symbol PK, thirteen that seemed to be arrested at the earlystage of spore germination were subjected to the further cytological and genetic analysis. Elght of these mutants are able to form germ tube and five not. Staining with acid fuchsin for the 5PK strains shows that one irreversible mutant, PK6 strain able to form germ tube, accumulate mitotic spindle, being arrested in mitosis. Another PK15 and PK23 strain have more than one intact nucleolus without germ tube formation at the restrictive temperature. the temperature-senstive mutation in PK12 strain, the onlystrain which is able occurred in certain gene specific for the germination of spore. All of the ts markers are recessive and complement each other in heterokaryon between two different ts markers at the restrictive temperature.

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Isolation and characterization of temperature-sensitive mutant of Saccharomycopsis lipolytica (Saccharomycopsis lipolytica의 온도감수성 변이균주의 분리 및 특성)

  • 조석금
    • Microbiology and Biotechnology Letters
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    • v.15 no.6
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    • pp.414-419
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    • 1987
  • Temperature-sensitive revertant could grow on acetic acid at 23$^{\circ}C$ but not at 33$^{\circ}C$, MX9-11RX8, isolated from mutant deficient in the activity of isocitrate lyase and its properties were investigated. The activity of isocitrate lyase and specific rate of isocitrate lyase synthesis decreased according to in-crease culture temperature from 23 to 33 $^{\circ}C$ in acetic acid as carbon source. A rapid cessation of in-crease enzyme activity observed when the temperature was shift up from 23 to 33$^{\circ}C$ but cell growth was continued. On the other hand, the revertant also exhibited temperature-sensitive in n-hexade-cane medium as carbon source, and the amount of isocitric acid was nearly equal produced to that at 23 $^{\circ}C$ when the temperature shift up from 23 to 33 $^{\circ}C$.

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Thermo-sensitive Clothing Development by Consumer Investigation and Wearing Test (소비자 조사와 착의 실험을 통한 온도감응형 기능성 의류개발을 위한 기초연구)

  • Sang, Jeong-Seon;Chung, Kyunghwa;Park, Juhyun;Oh, Kyung Wha
    • Fashion & Textile Research Journal
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    • v.19 no.1
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    • pp.90-100
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    • 2017
  • In this research, consumer awareness investigation and wearing test were carried out for obtaining useful data on the development of thermo-sensitive functional clothing material. A survey involved 216 people in Seoul and Kyeonggi-do, and 200 questionnaires data were analyzed by descriptive statistics and frequency using SPSS 17.0. Four healthy men in twenties were participated for wearing test. Subjects in normal loungewear were exposed to temperature change from the initial temperature $30^{\circ}C$ down to $5^{\circ}C$ for an hour in a climate chamber. The environmental temperature, surface temperature of garment and skin were measured. As a result, most of respondents have all season clothing products such as underwear, hosiery, and jogging suit for loungewear. Also, thermo regulator y functional clothes are frequently used as underwear and sweat shirt. The consumer awareness investigation on thermo regulatory functional clothing showed that the most important key buying factor is quick climate temperature response, easy maintenance, design and cost, in that order. Surface temperature of garment went down with the cooling down of environmental temperature. The lower environmental temperature, the greater temperature difference by body part showed. Skin temperature change by environmental temperature showed similar tendency of garment surface temperature. In comparison between garment surface and body skin, temperature difference became larger under the lower environmental temperature.

Retrieval of emissivity and land surface temperature from MODIS

  • Suh Myoung-Seok;Kang Jeon-Ho;Kim So-Hee;Kwak Chong-Heum
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.165-168
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    • 2005
  • In this study, emissivity and land surface temperature (LST) were retrieved using the previously developed algorithms and Aqua/MODIS data. And sensitivity of estimated emissivity and LST to the predefined values, such as land cover, normalized difference vegetation index (NOVI) and spectral emissivity were investigated. The methods used for emissivity and LST were vegetation cover method (VCM) and four different split-window algorithms. The spectral emissivity retrieved by VCM was not sensitive to the NOVI error but more sensitive to the land cover error. The comparison of LST showed that the LST was systematically different without regard to the land cover and season. And the LST was very sensitive to the emissivity error excepting the Uliveri et al. This preliminary result indicates that more works are needed for the retrieval of reliable LST from satellite data.

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Application of Temperature-Sensitive Mutations to Oncogene Studies in Drosophila

  • Baek, Kwang-Hyun
    • Archives of Pharmacal Research
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    • v.22 no.3
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    • pp.229-231
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    • 1999
  • Recessive oncogenes are genetic functions important in the regulation of tissue growth and differentiation. These genetic functions are defined on the basis of the phenotype expressed by homozygotes. Defining the role of these genes in normal developmental and physiological processes is important to the development of accurate models of the normal regulation of growth and differentiation. Drosophila can be a good system to investigate the neoplastic mechanism of oncogenes and provide a greater understanding in the developmental progression of both invertebrates and vertebrates and vertebrates. The lethal (2) giant larvae gene is a recessive oncogene of Drosophila and temperature sensitive mutations of this gene have been isolated. Here, the application of temperature-sensitive mutations in Drosophila oncogene studies is discussed.

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