• Title/Summary/Keyword: facilitated state

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Homogenized Elastic-plastic Relation based on Thermodynamics and Strain Localization Analyses for Particulate Composite (열역학 기반 내부 변수를 이용한 균질화 탄소성 구성방정식 및 입자강화 복합재에서의 소성변형집중)

  • S. J. Yun;K. K. Kim
    • Transactions of Materials Processing
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    • v.33 no.1
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    • pp.18-35
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    • 2024
  • In the present work, the evolution rules for the internal variables including continuum damage factors are obtained using the thermodynamic framework, which are in turn facilitated to derive the elastic-plastic constitutive relation for the particulate composites. Using the Mori-Tanaka scheme, the homogenization on state and internal variables such as back-stress and damage factors is carried out to procure the rate independent plasticity relations. Moreover, the degradation of mechanical properties of constituents is depicted by the distinctive damages such that the phase and interfacial damages are treated individually accordingly, whereas the kinematic hardening is depicted by combining the Armstrong-Frederick and Phillips' back-stress evolutions. On the other hand, the present constitutive relation for each phase is expressed in terms of the respective damage-free effective quantities, then, followed by transformation into the damage affected overall nominal relations using the aforementioned homogenization concentration factors. An emphasis is placed on the qualitative analyses for strain localization by observing the perturbation growth instead of the conventional bifurcation analyses. It turns out that the proposed constitutive model offers a wide range of strain localization behavior depending on the evolution of various internal variable descriptions.

At Death's Door: Alternaria Pathogenicity Mechanisms

  • Lawrence, Christopher B.;Mitchell, Thomas K.;Craven, Kelly D.;Cho, Yang-Rae;Cramer, Robert A.;Kim, Kwang-Hyung
    • The Plant Pathology Journal
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    • v.24 no.2
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    • pp.101-111
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    • 2008
  • The fungal genus Alternaria is comprised of many saprophytic and endophytic species, but is most well known as containing many notoriously destructive plant pathogens. There are over 4,000 Alternaria/host associations recorded in the USDA Fungal Host Index ranking the genus 10th among nearly 2,000 fungal genera based on the total number of host records. While few Alternaria species appear to have a sexual stage to their life cycles, the majority lack sexuality altogether. Many pathogenic species of Alternaria are prolific toxin producers, which facilitates their necrotrophic lifestyle. Necrotrophs must kill host cells prior to colonization, and thus these toxins are secreted to facilitate host cell death often by triggering genetically programmed apoptotic pathways or by directly causing cell damage resulting in necrosis. While many species of Alternaria produce toxins with rather broad host ranges, a closely-related group of agronomically important Alternaria species produce selective toxins with a very narrow range often to the cultivar level. Genes that code for and direct the biosynthesis of these host-specific toxins for the Alternaria alternata sensu lato lineages are often contained on small, mostly conditionally dispensable, chromosomes. Besides the role of toxins in Alternaria pathogenesis, relatively few genes and/or gene products have been identified that contribute to or are required for pathogenicity. Recently, the completion of the A. brassicicola genome sequencing project has facilitated the examination of a substantial subset of genes for their role in pathogenicity. In this review, we will highlight the role of toxins in Alternaria pathogenesis and the use of A. brassicicola as a model representative for basic virulence studies for the genus as a whole. The current status of these research efforts will be discussed.

Preparation of High-Purity Urokinase Using Single-Step Hydrophobic Interaction Chromatography with p-Aminobenzamidine Ligand

  • Cao, Xue-Jun;Zhou, Jian-Hua;Huang, Zhen-Hui;Wu, Xing-Yan;Hur, Byung-Ki
    • Journal of Microbiology and Biotechnology
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    • v.12 no.2
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    • pp.196-203
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    • 2002
  • A novel process for urokinase purification was studied using p-aminobenzamidine as the ligand and sepharose 4B as the matrix. The adsorption, washing, and elution conditions were optimized by an unusual method. An adsorption buffer containing 2.5 M NaCl and $1\%$ Tween 80 facilitated the adsorption of urokinase on the affinity media and prevented contaminants from binding to the p-aminobenzamidine affinity gel. It was found that $5\%$ Tween 80 removed most of the contaminants from the affinity column. A 0.2 M glycine elution buffer containing 0.5 M NaCl (pH 3.0) was found to have a strong elution ability with a high recovery and purity of urokinase. A crude urokinase material of231 IU/mg protein from human urine was purified to 124,300 IU/mg protein with a purification factor of 538 and yield of $86.7\%$. As a result, a high purity urokinase was obtained with only a single affinity chromatography step. The purification process was successfully scaled-up to a 2-1 chromatography column. The resulting urokinase eluate could be directly lyophilized, thereby complying with Chinese pharmacopoeia (1995 version) standards.

Systems Studies and Modeling of Advanced Life Support Systems

  • Kang, S.;Ting, K.C.;Both, A.J.
    • Agricultural and Biosystems Engineering
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    • v.2 no.2
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    • pp.41-49
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    • 2001
  • Advanced Life Support Systems(ALSS) are being studied to support human life during long-duration space missions. ALSS can be categorized into four subsystems: Crew, Biomass Production, Food Processing and Nutrition, Waste Processing and Resource Recovery. The System Studies and Modeling (SSM) team of New Jersey-NASA Specialized Center of Research and Training (NJ-NSCORT) has facilitated and conducted analyses of ALSS to address systems level issues. The underlying concept of the SSM work is to enable the effective utilization of information to aid in planning, analysis, design, management, and operation of ALSS and their components. Analytical tools and computer models for ALSS analyses have been developed and implemented for value-added information processing. The results of analyses heave been delivered through the internet for effective communication within the advanced life support (ALS) community. Several modeling paradigms have been explored by developing tools for use in systems analysis. they include objected-oriented approach for top-level models, procedureal approach for process-level models, and application of commercially available modeling tools such as $MATLAB^{R}$/$Simulink^{R}$. Every paradigm has its particular applicability for the purpose of modeling work. an overview is presented of the systems studies and modeling work conducted by the NJ-NSCORT SSM team in its efforts to provide systems analysis capabilities to the ALS community. The experience gained and the analytical tools developed from this work can be extended to solving problems encountered in general agriculture.

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On-Road Driving Performance Analysis of Diesel-Hybrid Bus in Daegu Metropolitan Area (대구지역 디젤하이브리드 버스의 실도로 주행 성능 분석)

  • Kim, Hyunjun;Chun, Bongsu;Han, Manbae;Han, Moonsik;Kim, Yongrae;Lee, Yonggyu;Choi, Kyonam;Jeong, Dongsoo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.2
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    • pp.27-33
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    • 2013
  • In this study we analyzed the on-road driving performance of two parallel-type diesel-hybrid buses which have been driven in Daegu metropolitan area. A real-time on-board data logger was facilitated to measure the vehicle information such as vehicle speed, idle stop, state of charge of battery, and engine operating conditions. These diesel-hybrid buses ran as a commuter at Daegu Exco area and Dalsung industrial complex. The driving pattern in Exco area comprised more frequent idle stop and relatively lower speed than at Dalsung area, where comprised no idle stop. Due to those different driving patterns, the fuel economy at Dalsung showed $3.7\;km/{\ell}$, which is about 8% higher than that of Exco. The main causes of this come from the higher portion of regenerative braking and higher speed which moves to the operating points of diesel engine with a lower fuel consumption.

Prospects For The Development Of Distance Educational Learning Technologies During The Training Of Students Of Higher Education

  • Rohach, Oksana;Pryhalinska, Tetiana;Kvasnytsya, Iryna;Pohorielov, Mykhailo;Rudnichenko, Mykola;Lastochkina, Olena
    • International Journal of Computer Science & Network Security
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    • v.22 no.9
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    • pp.353-357
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    • 2022
  • This article identifies the problems and substantiates the directions for the development of distance learning technologies in the training of personnel. An example of using digital media to create a remote access laboratory is given. The article is devoted to the definition of the main aspects of the organization of distance education. Rapid digitization, economic, political and social changes taking place in Ukraine necessitate the reform of the education system. First of all, it concerns meeting the educational needs of citizens throughout their lives, providing access to educational and professional training for all who have the necessary abilities and adequate training. The most effective solution to the above-mentioned problems is facilitated by distance learning. The article analyzes the essence and methods of distance learning organization, reveals the features of the use of electronic platforms for the organization of this form of education in different countries of the world. The positive characteristics of distance learning are identified, namely: extraterritoriality; savings on transport costs; the interest of modern youth in the use of information tools in everyday life; increase in the number of students; simplicity and accessibility of training; convenient consultation system; democratic relations between the student and the teacher; convenience for organizations in training their employees without interrupting their regular work; low level of payment for distance education compared to traditional education; individual learning pace; new teacher status. Among the negative features of online education, the author refers to the following problems: authentication of users during knowledge verification, calculation of the teacher's methodological load and copyright of educational materials; the high labor intensity of developing high-quality educational content and the high cost of distance learning equipment; the need to provide users with a personal computer and access to the Internet; the need to find and use effective motivation mechanisms for education seekers.

Concept Structures, Functional Equivalence and the East Asian Welfare State Discussion: An Application of Set Theory in Comparative Social Policy (개념구조, 기능적 등가물 그리고 동아시아복지국가론: 비교사회정책연구에서 집합이론의 활용)

  • Lee, Sophia Seung-yoon
    • 한국사회정책
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    • v.19 no.3
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    • pp.185-214
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    • 2012
  • After the introduction of the three welfare regimes by Esping-Andersen, discussion on 'other' types of welfare regimes was facilitated and the scholarly focus on East Asian economic development gradually shifted to the East Asian welfare states discussion from the late 1990s. Literature on East Asian welfare states increased our understanding on the characteristics of not only the East Asian welfare state as a whole but also of each country in the region. However, compared the attention given to developing variables and empirical studies on the East Asian welfare state, less attention has been given to the concept of East Asian welfare states. Recognizing the limitation in developing comparable variables without a concept analysis of the East Asian welfare states, this study highlights the importance of conceptualization and concept analysis in comparative social policy studies. This paper first discusses on the concepts, conceptualization and on the use of set theory in comparative social policy research. Next, the study argues the validity of 'functional equivalence' in the East Asian welfare state studies and critically reviews the existing literature. Lastly, this paper suggests how the concept of functional equivalence can be successfully employed for the East Asian welfare states studies with a concept analysis and by applying a set theory including the fuzzy set theory.

A Review of Industrially Developed Components and Operation Conditions for Anion Exchange Membrane Water Electrolysis

  • Lim, Ahyoun;Cho, Min Kyung;Lee, So Young;Kim, Hyoung-Juhn;Yoo, Sung Jong;Sung, Yung-Eun;Jang, Jong Hyun;Park, Hyun S.
    • Journal of Electrochemical Science and Technology
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    • v.8 no.4
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    • pp.265-273
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    • 2017
  • Solid-state alkaline water electrolysis is a promising method for producing hydrogen using renewable energy sources such as wind and solar power. Despite active investigations of component development for anion exchange membrane water electrolysis (AEMWE), understanding of the device performance remains insufficient for the commercialization of AEMWE. The study of assembled AEMWE devices is essential to validate the activity and stability of developed catalysts and electrolyte membranes, as well as the dependence of the performance on the device operating conditions. Herein, we review the development of catalysts and membranes reported by different AEMWE companies such as ACTA S.p.A. and Proton OnSite and device operating conditions that significantly affect the AEMWE performance. For example, $CuCoO_x$ and $LiCoO_2$ have been studied as oxygen evolution catalysts by Acta S.p.A and Proton OnSite, respectively. Anion exchange membranes based on polyethylene and polysulfone are also investigated for use as electrolyte membranes in AEMWE devices. In addition, operation factors, including temperature, electrolyte concentration and acidity, and solution feed methods, are reviewed in terms of their influence on the AEMWE performance. The reaction rate of water splitting generally increases with increase in operating temperature because of the facilitated kinetics and higher ion conductivity. The effect of solution feeding configuration on the AEMWE performance is explained, with a brief discussion on current AEMWE performance and device durability.

The Congestion Control using Selective Slope Control under Multiple Time Scale of TCP (TCP의 다중 시간 간격에서 선택적 기울기 제어를 이용한 혼잡 제어)

  • Kim, Gwang-Jun;Kang, Ki-Woong;Lim, Se-Jung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.2 no.1
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    • pp.10-18
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    • 2007
  • In this paper, we extend the multiple time scale control framework to window-based congestion control, in particular, TCP. This is performed by interfacing TCP with a large time scale control module which adjusts the aggressiveness of bandwidth consumption behavior exhibited by TCP as a function of "large time scale" network state. i.e., conformation that exceeds the horizon of the feedback loop as determined by RTT. Performance evaluation of multiple time scale TCP is facilitated by a simulation bench-mark environment which is based on physical modeling of self-similar traffic. If source traffic is not extended exceeding, when RTT is 450ms, in self similar burst environment, performance gain of TCP-SSC is up to 45% for ${\alpha}$=1.05. However, its is acquired only 20% performance gain for ${\alpha}$=1.95 relatively. Therefore we showed that by TCP-MTS at large time scale into a rate-based feedback congestion control, we are able to improve two times performance significantly.

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Antinociceptive Effect of the Intrathecal Phosphodiesterase Inhibitor, Zaprinast, in a Rat Formalin Test

  • Heo, Burn Young;Kim, Chang Mo;Jeong, Sung Tae;Kim, Seok Jai;Choi, Jeong II;Yoon, Myung Ha
    • The Korean Journal of Pain
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    • v.18 no.2
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    • pp.99-106
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    • 2005
  • Background: Cyclic guanosine monophosphate (cGMP) and opioid receptors are involved in the modulation of nociception. Although the opioid receptors agonists are active in pain, the effect of an phospodiesterase inhibitor (zaprinast) for increasing the level of cGMP has not been thoroughly investigated at the spinal level. This study examined the effects of intrathecal zaprinast and morphine in a nociceptive test and we also examined the nature of the pharmacological interaction after the coadministration of zaprinast with morphine. The role of the nitric oxide (NO)-cGMP-potassium channel pathway on the effect of zaprinast was further clarified. Methods: Catheters were inserted into the intrathecal space of male SD rats. For the induction of pain, $50{\mu}l$ of 5% formalin solution was applied to the hindpaw. Isobolographic analysis was used for the evaluation of the drug interaction between zaprinast and morphine. Furthermore, NO synthase inhibitor ($_L-NMMA$), guanylyl cyclase inhibitor (ODQ) or a potassium channel blocker (glibenclamide) were intrathecally administered to verify the involvement of the NO-cGMP- potassium channel pathway on the antinociception effect of zaprinast. Results: Both zaprinast and morphine produced an antinociceptive effect during phase 1 and phase 2 in the formalin test. Isobolographic analysis revealed a synergistic interaction after the intrathecal administration of the zaprinast-morphine mixture in both phases. Intrathecal $_L-NMMA$, ODQ and glibenclamide did not reverse the antinociception of zaprinast in either phase. Conclusions: These results suggest that zaprinast, morphine and the mixture of the two drugs are effective against acute pain and they facilitated pain state at the spinal level. Thus, the spinal combination of zaprinast with morphine may be useful for the management of pain. However, the NO-sensitive cGMP-potassium channel pathway did not contribute to the antinocieptive mechanism of zaprinast in the spinal cord.