• Title/Summary/Keyword: homogeneous system

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A Study on Flammability and Mechanical Properties of HDPE/EPDM/Boron Carbide/Triphenyl Phosphate Blends with Compatibilizer (HDPE/EPDM/Boron Carbide/Triphenyl Phosphate 블렌드의 상용화제 첨가에 따른 난연성 및 기계적 물성 연구)

  • Shin, Bum-Sik;Jung, Seung-Tae;Jeun, Joon-Pyo;Kim, Hyun-Bin;Oh, Seung-Hwan;Kang, Phil-Hyun
    • Polymer(Korea)
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    • v.36 no.5
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    • pp.549-554
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    • 2012
  • It was known that triphenyl phosphate wasn't homogeneously dispersed in HDPE/EPDM/boron carbide blends, which caused the decrease in mechanical properties. HDPE, EPDM, boron carbide, and triphenyl phosphate were blended with PE-g-MAH(polyethylene-graft-maleic anhydride) as a compatiblizer for improving the miscibility of triphenyl phosphate. Tensile strength of HDPE/EPDM/boron carbide blends decreased with increasing the contents of triphenyl phosphate for flammability. However, the mechanical properties of HDPE/EPDM/boron carbide/triphenyl phosphate blends increased by the addition of compatiblizer because triphenyl phosphate was homogeneously mixed in the blend system. The homogeneous dispersibility of triphenyl phosphate was confirmed by using scanning electron microscopy (SEM). Increased thermal stability and flammability derived from high miscibility of triphenyl phosphate were confirmed by the results of thermogravimetric analysis (TGA) and limiting oxygen index (LOI). A self-extinguishing HDPE/EPDM/boron carbide/triphenyl phosphate blend was successfully fabricated with more than 21% LOI.

Layout Principles of Renaissance Classicism Architectural Style and Its Application on Modern Fashion Design - Focused on Classic Style Fashion after the Year 1999 - (르네상스 고전주의 건축양식의 조형원리와 현대패션디자인에의 적용 - 1999년 이후 클래식 스타일 패션을 중심으로 -)

  • Lee, Shin-Young
    • The Research Journal of the Costume Culture
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    • v.18 no.2
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    • pp.261-276
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    • 2010
  • The analysis of an art trend in the principle dimension starts by observing the object of work in the perspective of formative composition and recognizing it as a universal system. It can be said that it is consistent with an interpretation method for a form theory of formal history by Heinrich W$\ddot{o}$lfflin, a leading form critic in art criticism. Hence, the purpose of this study was to find out what are the formative principles in Renaissance Classicism as a design principle to be applicable to modern fashion by reviewing the formative characteristics of Renaissance Classicism Architecture with which W$\ddot{o}$lfflin directly dealt. As for the theoretical literature review, I used W$\ddot{o}$lfflin's theoretical framework and looked at the Renaissance Classicism Architecture that he studied and examined the possibility of utilizing his theory as a layout principle and the characteristics. As for analysis of design cases, I applied the aforementioned architecture layout principle to modern fashion and conducted case study analysis to delve into distinctive layout principles found in fashion. The study showed that the Renaissance Classicism Architectural Style is marked by linearity, planarity, closing and multiple unity: linearity was expressed in the observation form in fixed frontal view and an emphasis on a tangible silhouette homeogenous and definite line structures; planarity was achieved in the form of paralleled layers of frontal view element, planarity style, and identical and proportional repetition of various sizes.; closing signified the pursuit of complete and clear regularity, and architecture developed in a constructive phase through organizational inevitability and absolute invariability.; multiple unity was expressed in self-completedness and independent parallel of discrete forms and harmony of emphasized individual elements in a totality. Applying these layout characteristics of the Renaissance Classicism Architectural style and to see their individual expressive features, I found out that in adopting layout principles of the Renaissance Classicism Architecture to modern fashion, it turned out to be an emphasis of individual silhouettes, a flattened space, completed objects, organic harmony among independent parts: the emphasis of individual silhouettes was expressed in individual definitiveness of formative lines of clothes in accordance with body joints and an emphasis on formative lines of clothes; the flattened space was marked by single layer structure, planarity of elements of clothes, and listing arrangement by appropriate proportion.; the completedness of the objects was expressed by the stationary state where overall image is fixed, the construction of homogeneous and complete space, and absolute inevitability of internal layout in proportion; lastly, organic harmony of independent parts was stressed in independent completedness of each detail, and organic harmony of the whole. The expressive features would lead to a unique expression style of linear emphasis, proportion, constructive forms, and two-dimensional arrangement. The meaning of this study is follows: The characteristics of art school of thought are given shape by appling & analysing the architectural layout principles of historical art school of thought to modern fashion in the view point of formal construction dimension. The applied possibility of historical art school of thought as the source of inspiration about the fashion design is extended.

Site Investigation for Pilot Scale $CO_2$ Sequestration by Magnetotelluric Surveys in Uiseong, Korea (이산화탄소 지중저장 Pilot 부지 선정을 위한 의성지역 MT 탐사)

  • Lee, Tae-Jong;Han, Nu-Ree;Ko, Kwang-Beom;Hwang, Se-Ho;Park, Kwon-Gyu;Kim, Hyung-Chan;Park, Yong-Chan
    • Geophysics and Geophysical Exploration
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    • v.12 no.4
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    • pp.299-308
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    • 2009
  • A magentotelluric (MT) survey at the Uiseong area has been performed for the site investigation of pilot scale $CO_2$ sequestration. The purpose of the MT survey is to delineate deeply extended fracture systems that can act as a leakage path of injected $CO_2$ Plume. Since the target area is extremely noisy in electromagentic sense, low frequency data below 1 Hz cannot be used for inversion. Two- and three-dimensional interpretation of the MT data showed a very clear conductive anomaly, which has the direction of $N55\sim65^{\circ}W$ and is extended roughly down to 1.6 km. It have the same direction with the strike-slip faults, the Gaeum and Geumcheon Faults. On the contrary, the eastern part of the survey area shows relatively homogeneous to the depth of 2 km though some small fractures at shallow depths can be found. Test drilling and high-definition borehole surveys should be followed at the eastern part of the survey area and hydraulic fracturing is required for injection of $CO_2$, because mean porosity of the sedimetary rock in the area is only 1.47%.

Dynamic Optimization of a Reactive Distillation Column Producing Methyl Acetate (메틸 아세테이트 생산을 위한 반응증류 공정의 동적 최적화)

  • Kim, Jiyong;Kim, Junghwan;Moon, Il
    • Korean Chemical Engineering Research
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    • v.46 no.4
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    • pp.739-746
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    • 2008
  • The aim of this study is finding the optimal design parameters and the optimal operation variables of a reactive distillation column. Different from steady state optimization, dynamic optimization makes it possible considering operation ability as well as design problems at process design step. For performing dynamic optimization, dynamic simulation should be done first. If dynamic simulation is already finished, dynamic optimization can be performed with less effort than that of dynamic simulation.Reactive distillation systems involving reaction and separation in a single unit have the potential to reduce capital and operating costs, particularly when reaction have conversion constraint or when azeotropes exist making conventional separation difficult and expensive. This study here present work on the continuous distillation process, the homogeneous catalyzed esterification of methanol and acetic acid, the synthesis of methyl acetate. Based on an equilibrium stage model of a reactive distillation column a dynamic optimization problem was formulated and solved. And the results were verified by performing dynamic simulation and showing the variation of conversion and purity as the variation of the operation variables. As the results of dynamic optimization, this study found optimal feed ratio, reflux ratio and reboiler duty of this system. And as this study applied it to dynamic simulations the dynamic characteristics of a reactive distillation column are showed under optimal operating condition.

Structural and Piezoelectric Properties of MnO2-Doped PZT-PSN Ceramics for Ultrasonic Vibrator (초음파 진동자용 MnO2가 Doping된 PZT-PSN 세라믹스의 구조 및 압전 특성)

  • Cha, Yoo-Jeong;Kim, Chang-Il;Kim, Kyoung-Jun;Jeong, Young-Hun;Lee, Young-Jin;Lee, Hai-Gun;Paik, Jong-Hoo
    • Korean Journal of Materials Research
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    • v.19 no.4
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    • pp.198-202
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    • 2009
  • For use in ultrasonic actuators, we investigated the structural and piezoelectric properties of $(1\;-\;x)Pb(Zr_{0.515}Ti_{0.485})O_3$ - $xPb(Sb_{1/2}Nb_{1/2})O_3$ + 0.5 wt% $MnO_2$ [(1 - x)PZT - xPSN + $MnO_2$] ceramics with a variation of x (x = 0.02, 0.04, 0.06, 0.08). All the ceramics, which were sintered at $1250^{\circ}C$ for 2 h, showed a typical perovskite structure, implying that they were well synthesized. A homogeneous micro structure was also developed for the specimens, and their average grain size was slightly decreased to $1.3{\mu}m$ by increasing x to 0.8. Moreover, a second phase with a pyrochlore structure appeared when x was above 0.06, which resulted in the deterioration of their piezoelectric properties. However, the 0.96PZT-0.04PSN+$MnO_2$ ceramics, which corresponds with a morphotropic phase boundary (MPB) composition in the (1 - x)PZT - xPSN + $MnO_2$ system, exhibited good piezoelectric properties: a piezoelectric constant ($d_{33}$) of 325 pC/N, an electromechanical coupling factor ($k_p$) of 70.8%, and a mechanical quality factor ($Q_m$) of 1779. The specimens with a relatively high curie temperature ($T_c$) of $305^{\circ}C$ also showed a significantly high dielectric constant (${\varepsilon}_r$) value of 1109. Therefore, the 0.96PZT - 0.04PSN + $MnO_2$ ceramics are suitable for use in ultrasonic vibrators.

An Application of Artificial Intelligence System for Accuracy Improvement in Classification of Remotely Sensed Images (원격탐사 영상의 분류정확도 향상을 위한 인공지능형 시스템의 적용)

  • 양인태;한성만;박재국
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.1
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    • pp.21-31
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    • 2002
  • This study applied each Neural Networks theory and Fuzzy Set theory to improve accuracy in remotely sensed images. Remotely sensed data have been used to map land cover. The accuracy is dependent on a range of factors related to the data set and methods used. Thus, the accuracy of maps derived from conventional supervised image classification techniques is a function of factors related to the training, allocation, and testing stages of the classification. Conventional image classification techniques assume that all the pixels within the image are pure. That is, that they represent an area of homogeneous cover of a single land-cover class. But, this assumption is often untenable with pixels of mixed land-cover composition abundant in an image. Mixed pixels are a major problem in land-cover mapping applications. For each pixel, the strengths of class membership derived in the classification may be related to its land-cover composition. Fuzzy classification techniques are the concept of a pixel having a degree of membership to all classes is fundamental to fuzzy-sets-based techniques. A major problem with the fuzzy-sets and probabilistic methods is that they are slow and computational demanding. For analyzing large data sets and rapid processing, alterative techniques are required. One particularly attractive approach is the use of artificial neural networks. These are non-parametric techniques which have been shown to generally be capable of classifying data as or more accurately than conventional classifiers. An artificial neural networks, once trained, may classify data extremely rapidly as the classification process may be reduced to the solution of a large number of extremely simple calculations which may be performed in parallel.

Synthesis of Cyclododecatriene from 1,3-Butadiene by Trimerization over Amine-Titanium Complex Catalyst (아민-티타늄착체 촉매상에서 1,3-부타디엔의 삼량화반응에 의한 싸이클로도데카트리엔의 합성)

  • Park, Da Min;Kim, Gye-Ryeong;Lee, Ju Hyun;Cho, Deuk Hee;Kim, Geon-Joong
    • Korean Chemical Engineering Research
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    • v.51 no.3
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    • pp.394-402
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    • 2013
  • The new complex catalysts were synthesized by the reaction of titanium compounds (titanium chloride or titanium butoxide) and diamines in this work, and they showed very high catalytic activities for the cyclododecatriene (CDT) synthesis from 1,3-butadiene through trimerization. CDT synthetic reaction was performed in an autoclave reactor, and the effects of reaction temperature, type of catalyst, catalyst amount added into the system, the mole ratio of Al/Ti and immobilization method were investigated on the yield of product CDT. The titanium complex catalyst combined to diamine with 1:1 ratio showed high selectivity to CDT more than 90%. The ratio of TTT-CDT/TTC-CDT isomers in the product revealed as different values, depending on the type of diamine combined to titanium and Ti/diamine ratios. Those homogeneous complexes could be used as a heterogenized catalyst after anchoring on the supports, and the immobilized titanium catalyst retained the catalytic activities for several times in the recycled reactions without leaching. The carbon support containing titanium has exhibited superior activity to the silica support. Especially, when the titanium complex was anchored on the support which was fabricated by the hydrolysis of tripropylaminosilane itself, the resulting titanium catalyst showed the highest BD conversion and CDT selectivity.

A Study on the Subjectivity with Curriculum in Food·Cooking Area Based on NCS -Focusing on Graduates of Hotel Cooking Department in Incheon Region- (NCS기반 음식·조리분야 교육과정의 주관적 인식에 관한 연구 -인천지역 호텔조리학과 졸업생을 중심으로-)

  • Kim, Chan-Woo;Kim, Dong-Soo
    • The Journal of the Korea Contents Association
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    • v.17 no.9
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    • pp.192-202
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    • 2017
  • This study analyzed the influence relations of the subjectivity of satisfaction with curriculum in food cooking area based on NCS by applying Q methodology, targeting graduates of hotel cooking department in college. This paper largely suggests two research questions like following. Research Question 1: What are the acceptance types of satisfaction with curriculum in food cooking area based on NCS? Research Question 2: What are the homogeneous characteristics and implications of each type? In the results of typological analysis based on such research questions, total four types were drawn like following: Type1(N=7): Basic Practical Classes Pursuit-type, Type2(N=5): Domestic Employment Preference-type, Type3(N=5): Famous Chef Inviting Class Pursuit-type, and Type4(N=3): Tailor-Made Lessons Pursuit-type. Each type showed its own distinctive characteristics. In this study, the graduates' perception in a specific cooking department would be used as a basis for follow-up researches. In the future, it would be necessary to have researches to establish the customized-curriculum system such as planning/operating student-centered teaching/learning guidelines and also conducting mentoring programs. Also, it is expected to have continuous follow-up researches to complement the limitations of this study.

Plankton Community in Weir Section of the Nakdong River and Its Relation with Selected Environmental Factors (낙동강 보 구간의 플랑크톤 군집조성과 환경요인에 의한 영향 분석)

  • Seo, Dong-Il;Nam, Gui-Sook;Lee, Sang-Hyup;Lee, Eui-Haeng;Kim, Mirinae;Choi, Jong-Yun;Kim, Jeong-Hui;Chang, Kwang-Hyeon
    • Korean Journal of Environmental Biology
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    • v.31 no.4
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    • pp.362-369
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    • 2013
  • Phytoplankton and zooplankton communities were investigated from 8 weir sites of the Nakdong River system to provide basic information on plankton community after weir construction and to estimate its effects on major water quality parameters. The relationship between plankton community structure and environmental factors was analysed with CCA (Canonical Correspondence Analysis). The results suggested that discharge and total phosphorus and nitrogen concentrations are important factors determining the phytoplankton species composition. For zooplankton community, the difference in discharge between September and October induced different distribution pattern of zooplankton community with more homogeneous distribution with extreme dominance of rotifers during the high discharge season. Chlorophyll a concentration representing phytoplankton biomass has been suggested as the main environmental factor affecting zooplankton community followed by COD and total nitrogen concentration.

A Study on Interdependence of Private Security and Techniques of CPTED (민간경비와 환경설계를 통한 범죄예방(CPTED) 기법의 상호의존성에 관한 연구)

  • Lee, Jung-Duk;Lim, You-Seok
    • Korean Security Journal
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    • no.29
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    • pp.223-249
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    • 2011
  • In modern society, citizens' quality of life aspects of safety and crime prevention activities are actively considering the incidence of crime prevention in advance. It also can be quite important elicit the interest of who community members through effective crime prevention strategies. For crime prevention policies and techniques over time as more scientific and advanced methods are made. Today, A typical crime prevention strategies is private security zones and Crime Prevention Through Environmental Design (CPTED) is a corresponding to the new strategy. CPTED is a diversification can be called a crime prevention approach that emphasizes the principle of natural surveillance, access control, territoriality, activity support, maintenance and management. The defensible space of the space area related to crime prevention setting the activities of private security and CPTED determine. Also, the reality of crime prevention and protection should be considered space. The emphasis on proactive prevention of crime in modern society for the prevention of crime how to approach differing perspectives and disparate aspects of private security and CPTED. Technical and professional areas that overlap to some extent in a homogeneous aspect. Ultimately, CPTED is a crime prevention through space and environmental approach for crime. In addition, Ultimate goal of convergence, crime prevention, with the same or higher is required to study for the area after looking for the characteristics and limitations of private security and CPTED.

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