• 제목/요약/키워드: Biological aspect

검색결과 216건 처리시간 0.03초

Stability analysis of a three-layer film casting process

  • Lee, Joo-Sung;Shin, Dong-Myeong;Jung, Hyun-Wook;Hyun, Jae-Chun
    • Korea-Australia Rheology Journal
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    • 제19권1호
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    • pp.27-33
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    • 2007
  • The co-extrusion of multi-layer films has been studied with the focus on its process stability. As in the single-layer film casting process, the productivity of the industrially important multi-layer film casting and the quality of thus produced films have often been hampered by various instabilities occurring in the process including draw resonance, a supercritical Hopfbifurcation instability, frequently encountered when the draw ratio is raised beyond a certain critical value. In this study, this draw resonance instability along with the neck-in of the film width has been investigated for a three-layer film casting using a varying width non-isothermal 1-D model of the system with Phan-Thien and Tanner (PTT) constitutive equation known for its robustness in portraying extensional deformation processes. The effects of various process conditions, e.g., the aspect ratio, the thickness ratio of the individual film layers, and cooling of the process, on the stability have been examined through the nonlinear stability analysis.

한국산 진범 종집단의 서식상황: GIS를 이용한 분석과 검증 (Distribution of Subgenus Lycoctonum in Korea: Analysis and Verification by GIS)

  • 이수랑;정종철;박종욱
    • Spatial Information Research
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    • 제15권2호
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    • pp.135-146
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    • 2007
  • 국내에 분포하는 진범아속의 식물종 개체군을 대상으로 GIS분석을 통해 서식환경을 분석 검증함으로써 이를 통해 환경변화에 취약한 고산식물종의 보전과 관리를 위한 새로운 방안을 모색하고자 본 연구를 수행하였다. 표본조사와 문헌조사를 바탕으로 작성된 진범아속의 분포도를 중심으로 현장조사에서 정확한 분포좌표와 서식환경 등의 지리적 및 생물학적 인자를 조사하여 이를 바탕으로 수치지형도를 이용하여 서식지 모형을 만들어냈다. 진범아속의 식물개체군은 해발고도 $470{\sim}1320m$ 구간이며 북향의 $15.5{\sim}36^{\circ}$ 사이의 경사지역으로 수계에서 가까운 활엽수림에 주로 분포하였다. 이를 바탕으로 GIS 프로그램을 사용하여 서울인근의 양수와 목동 두 개의 도엽에서 고도 향 경사 등의 요소의 중첩과 수계와의 거리, 토지피복분류에 따른 주변 식생 등을 조합하여 적합서식지를 확인하였고 현장 검증에서 이 적합서식지에 실제 진범아속 식물의 분포를 검증하였다. 이를 통하여 보전을 요하는 식물군의 미확인 서식지의 추측이나 대체서식지의 선정과정에 있어 GIS가 획기적으로 사용될 수 있음을 확인하였다.

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신약개발을 위한 임상연구간호사의 역할수행과 관련 요인 (Role Performance and Related Factors of Clinical Research Nurses in New Drug Development)

  • 박재은;김신미
    • Journal of Korean Biological Nursing Science
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    • 제22권3호
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    • pp.213-221
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    • 2020
  • Purpose: The purpose of this study was to explore the role performance and related factors of clinical research nurses (CRN) in the process of clinical trials of new drug development. Methods: Study participants were CRN whose affiliation was in non-capital areas and who had been working longer than three months at the time of the data collection. The data collection was conducted with a semi-structured questionnaire development by Hwang & Go, 2011 comprising 16 items of participants' characteristics and 60 items of role performance via in-person and online. Additionally, opinions which would be necessary to establish the CRN role were questioned for the future. A total of 141 questionnaires of 151 questionnaires responses were analyzed using descriptive statistics, t-test, and ANOVA for data analysis as appropriate. Results: The level of overall role performance was above average (5.61±0.90) with the highest in subject care (6.04 ± 0.96) and management and the lowest in self-development (4.39 ± 1.52). The only factor affecting overall role performance was employment status and the only sub-category affected by factors of employment status, and some general characteristics was self-development. Conclusion: From study results, it can be concluded that the CRN seem to perform their proper role. Nonetheless, self-development should be considered as critical aspect for better CRN competency, which is an important aspect toward improving the CRN role performance. Additionally, efforts to improve the level of role performance must be established through stable employment and concrete departmental placement as suggested in this study.

Effects of Three Thiazolidinediones on Metabolic Regulation and Cold-Induced Thermogenesis

  • Sohn, Jee Hyung;Kim, Jong In;Jeon, Yong Geun;Park, Jeu;Kim, Jae Bum
    • Molecules and Cells
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    • 제41권10호
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    • pp.900-908
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    • 2018
  • Insulin resistance is closely associated with metabolic diseases such as type 2 diabetes, dyslipidemia, hypertension and atherosclerosis. Thiazolidinediones (TZDs) have been developed to ameliorate insulin resistance by activation of peroxisome proliferator-activated receptor (PPAR) ${\gamma}$. Although TZDs are synthetic ligands for $PPAR{\gamma}$, metabolic outcomes of each TZD are different. Moreover, there are lack of head-to-head comparative studies among TZDs in the aspect of metabolic outcomes. In this study, we analyzed the effects of three TZDs, including lobeglitazone (Lobe), rosiglitazone (Rosi), and pioglitazone (Pio) on metabolic and thermogenic regulation. In adipocytes, Lobe more potently stimulated adipogenesis and insulin-dependent glucose uptake than Rosi and Pio. In the presence of pro-inflammatory stimuli, Lobe efficiently suppressed expressions of pro-inflammatory genes in macrophages and adipocytes. In obese and diabetic db/db mice, Lobe effectively promoted insulin-stimulated glucose uptake and suppressed pro-inflammatory responses in epididymal white adipose tissue (EAT), leading to improve glucose intolerance. Compared to other two TZDs, Lobe enhanced beige adipocyte formation and thermogenic gene expression in inguinal white adipose tissue (IAT) of lean mice, which would be attributable to cold-induced thermogenesis. Collectively, these comparison data suggest that Lobe could relieve insulin resistance and enhance thermogenesis at low-concentration conditions where Rosi and Pio are less effective.

생태학의 원리에 기초한 환경교육 방법의 모색 (Groping the Environmental Education Method based on the Ecological Principles)

  • 이창석;유영한
    • 한국환경교육학회지:환경교육
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    • 제15권2호
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    • pp.1-13
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    • 2002
  • The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

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Effects of Filler Characteristics and Processing Conditions on the Electrical, Morphological and Rheological Properties of PE and PP with Conductive Filler Composites

  • Kim, Youn-Hee;Kim, Dong-Hyun;Kim, Ji-Mun;Kim, Sung-Hyun;Kim, Woo-Nyon;Lee, Heon-Sang
    • Macromolecular Research
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    • 제17권2호
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    • pp.110-115
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    • 2009
  • The electrical, morphological and rheological properties of melt and dry mixed composites of poly ethylene (PE)/graphite (Gr), polypropylene (PP)/Gr and PP/nickel-coated carbon fiber (NCCF) were investigated as a function of filler type, filler content and processing temperature. The electrical conductivities of dry mixed PP/NCCF composites were increased with decreasing processing temperature. For the melt mixed PP/NCCF composites, the electrical conductivities were higher than those of the melt mixed PE/Gr and PP/Gr composites, which was attributed to the effect of the higher NCCF aspect ratio in allowing the composites to form a more conductive network in the polymer matrix than the graphite does. From the results of morphological studies, the fillers in the dry mixed PP/NCCF composites were more randomly dispersed compared to those in the melt mixed PP/NCCF composites. The increased electrical conductivities of the dry mixed composites were attributed to the more random dispersion of NCCF compared to that of the melt mixed PP/NCCF composites. The complex viscosities of the PP/Gr composites were higher than those of the PP/NCCF composites, which was attributed to the larger diameter of the graphite particles than that of the NCCF. Furthermore, the fiber orientation in the 'along the flow' direction during melt mixing was attributed to the decreased complex viscosities of the melt mixed PP/NCCF composites compared those of the melt mixed PP/Gr composites.

생태학의 원리에 기초한 환경교육 방법의 모색 (Groping the Environmental Education Method Based on the Ecological Principles)

  • 이창석
    • 한국환경교육학회지:환경교육
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    • 제15권1호
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    • pp.137-147
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    • 2002
  • The progress of environmental science and technology in the developed countries has been rapid in recent years. Particularly remarkable has been the advancement of various pollutant control measures, which have brought the pollution of inorganic factors such as air and water under control. In contrast, diversity of the ecosphere, of which man is a part, is being steadily Impoverished and the biological community is getting unvaryingly uniform. These phenomena were brought about by the expansion of artificial environment such as new industrial complexes, transportation facilities and urban development. Man has constructed uniform and artificial environment, believing in the premise of confrontation with nature, to such a scale that the natural environment and biological community have lost their balance. This will increasingly endanger the soundness of the biotic environment of nature, which constitutes the potential foundation both for the survival environment of man as biological entity and for the development of human civilization. In order to guarantee the soundness of man's body, intelligence and sensitivity as wholesome gene Pool on the earth and for the future of man, primarily important environmental education is the understanding of how man can everlasting exist in and with the survival environment. In view of this reality, it is vitally important to create ecologically diverse and well-balanced environment with living materials, i.e., vegetation in order to secure lasting survival environment for man. This task is urgently required in highly artificial environment where non-biological materials have forced the impoverishment of the biological community. Therefore, environmental education for the future should not be totally oriented to technology as that in the past nor it is limited to the medical aspect where well-being of human is the sole object of concern. That is to say, environmental education for the future should be one that provides knowledge that human can understand his place based on the ecological concept and thereby make him to have ethical consciousness that he can control his behavior within the reasonable level for ecological niche who he is located.

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현대(現代) 소비사회(消費社會)의 패션에 표현(表現)된 포스트모던페미니즘 (Postmodern Feminism Expressed in the Fashion of Modern Consumer Society)

  • 박미령
    • 패션비즈니스
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    • 제7권2호
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    • pp.26-36
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    • 2003
  • The purpose of this study is to examine the concept of modern consumer society and to analyze how the meaning of postmodern-feminism is consumed into what image of preference in fashion. The function of modern society has changed into the system which is centered around consumption from the one that emphasizes labor and production of mass consumption age by mass production. In this consumer society, consumption means just not to waste of production but to consume the commodity sign reflected on the desire of a moderner. In other words, it means what is consumed will be the meaning, preference, symbol, and image mood not goods itself with physical feature. Existing feminism has affected by postmodernism. Due to that, postmodern-feminism has developed, taking to pieces the paternal argument since the late 1960s. It has tried to give up hope this idea, regarding sex distinction as a socially organized category contrary to women's identity of biological aspect suppressed in the paternal system of value. Especially it has demanded only one type on sex should be translated into a distinctive quality, multiple meaning, and sex. Accordingly in modern fashion, this aspect is expressed like the followings : distinction into women's image evaded fixation, multiple meaning into image of androgyny, multiple sex into that of mixture. And this is used as the image of symbolic goods, also the purpose of brand difference.

유기농경지 농업생산경관 구성요소에 대한 전문가 인식 조사 (A Survey of Expert's Perceptions about Landscape Elements in Organic Farmland)

  • 안필균;안난희;신지훈;신재훈
    • 한국유기농업학회지
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    • 제24권4호
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    • pp.681-698
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    • 2016
  • With increasing public concern for environmentally friendly agriculture, ecological aspect of landscape management is of growing importance. AHP (Analytical Hierarchy Process) analysis were conducted based on the delphi survey of 31 experts to evaluate the relative importance and the preference of landscape elements. Landscape components of organic farmland were classified into 2 landscape fields, 5 landscape types, 14 landscape units, and 37 landscape elements. Overall relevance score for the proposed landscape components were about 5.5 on the seven point scale. While the relative importance weight of cropland landscape field was 0.71, the weight of intra-structure landscape field was 0.29. Among the cropland landscape, relatively higher weight was assigned to farming system (0.47) and margins (0.31), as compared with hydrological system (0.22). In the farming system, crop (0.40) and farm land (0.39) were the most important landscape units. In the margins, higher weight was given to Buffer zone (0.44) and Trees (0.42). Biological habitat (0.43) ranked the highest score in the hydrological system. Preferable landscape elements were glass house, companion plants, rice paddy field, diverse crop species, small pond, and small river, which are representing ecological advantage of organic farming systems. This result indicated that the landscape elements identified in the study would be suitable to evaluate ecological aspect of rural landscape in organic farmland.

공간규모별 치유농업단지 입지잠재력 평가 (Evaluation of Suitable Locations of Green Care Farm Complex According to Spatial Scale)

  • 임혜지;배승종;구희동;김대식
    • 농촌계획
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    • 제27권3호
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    • pp.93-102
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    • 2021
  • This study was attempted to provide a scientific basis for the problem of location selection by spatial scale for efficient promotion of projects related to green care farm complex. Location potential assessment system in local government scale consists of two major components from demand-side and supply-side consideration. The demand-side aspect considered the characteristics of potential users, while supply-side aspect used total 18 indices over 8 divisions under 3 fields. For the location potential assessment in district scale, total 8 indices under 3 major divisions were considered based on biological, physical, social, and economic environment. The application results of the location potential evaluation system in local government scale(excluding metropolitan cities) showed high location potential in southern Gyeonggi Province and near Busan Metropolitan City. As a result of applying the district-scale location potential evaluation system to Geumsan-gun, Geumsan-eup, Chubu-myeon, and Jewon-myeon have high potential. Further studies to improve the applicability of the developed indices are recommended by enhancing assessment indices, complementing base data, and reinforcing with spatial analysis.