Nonlinear dynamic response of electro-thermo-mechanically loaded piezoelectric cylindrical shell reinforced with BNNTs

International Nuclear Information System (INIS)

Yang, J H; Yang, J; Kitipornchai, S

2012-01-01

This paper presents an investigation on the nonlinear dynamic response of piezoelectric cylindrical shells reinforced with boron nitride nanotubes (BNNTs) under a combined axisymmetric electro-thermo-mechanical loading. By employing the classical Donnell shell theory, the von Kármán–Donnell kinematic relationship, and a piezo-elastic constitutive law including thermal effects, the nonlinear governing equations of motion of the shell are derived through the Reissner variational principle. The finite difference method and a time-integration scheme are used to obtain the nonlinear dynamic response of the BNNT-reinforced piezoelectric shell. A parametric study is conducted, showing the effects of geometrically nonlinear deformation, applied voltage, temperature change, mechanical load, BNNT volume fraction and boundary conditions on the nonlinear dynamic response. (paper)

Discovering governing equations from data by sparse identification of nonlinear dynamical systems.

Science.gov (United States)

Brunton, Steven L; Proctor, Joshua L; Kutz, J Nathan

2016-04-12

Extracting governing equations from data is a central challenge in many diverse areas of science and engineering. Data are abundant whereas models often remain elusive, as in climate science, neuroscience, ecology, finance, and epidemiology, to name only a few examples. In this work, we combine sparsity-promoting techniques and machine learning with nonlinear dynamical systems to discover governing equations from noisy measurement data. The only assumption about the structure of the model is that there are only a few important terms that govern the dynamics, so that the equations are sparse in the space of possible functions; this assumption holds for many physical systems in an appropriate basis. In particular, we use sparse regression to determine the fewest terms in the dynamic governing equations required to accurately represent the data. This results in parsimonious models that balance accuracy with model complexity to avoid overfitting. We demonstrate the algorithm on a wide range of problems, from simple canonical systems, including linear and nonlinear oscillators and the chaotic Lorenz system, to the fluid vortex shedding behind an obstacle. The fluid example illustrates the ability of this method to discover the underlying dynamics of a system that took experts in the community nearly 30 years to resolve. We also show that this method generalizes to parameterized systems and systems that are time-varying or have external forcing.

Discovering governing equations from data by sparse identification of nonlinear dynamics

Science.gov (United States)

Brunton, Steven

The ability to discover physical laws and governing equations from data is one of humankind's greatest intellectual achievements. A quantitative understanding of dynamic constraints and balances in nature has facilitated rapid development of knowledge and enabled advanced technology, including aircraft, combustion engines, satellites, and electrical power. There are many more critical data-driven problems, such as understanding cognition from neural recordings, inferring patterns in climate, determining stability of financial markets, predicting and suppressing the spread of disease, and controlling turbulence for greener transportation and energy. With abundant data and elusive laws, data-driven discovery of dynamics will continue to play an increasingly important role in these efforts. This work develops a general framework to discover the governing equations underlying a dynamical system simply from data measurements, leveraging advances in sparsity-promoting techniques and machine learning. The resulting models are parsimonious, balancing model complexity with descriptive ability while avoiding overfitting. The only assumption about the structure of the model is that there are only a few important terms that govern the dynamics, so that the equations are sparse in the space of possible functions. This perspective, combining dynamical systems with machine learning and sparse sensing, is explored with the overarching goal of real-time closed-loop feedback control of complex systems. This is joint work with Joshua L. Proctor and J. Nathan Kutz. Video Abstract: https://www.youtube.com/watch?v=gSCa78TIldg

Nonlinear dynamic mechanism of vocal tremor from voice analysis and model simulations

Science.gov (United States)

Zhang, Yu; Jiang, Jack J.

2008-09-01

Nonlinear dynamic analysis and model simulations are used to study the nonlinear dynamic characteristics of vocal folds with vocal tremor, which can typically be characterized by low-frequency modulation and aperiodicity. Tremor voices from patients with disorders such as paresis, Parkinson's disease, hyperfunction, and adductor spasmodic dysphonia show low-dimensional characteristics, differing from random noise. Correlation dimension analysis statistically distinguishes tremor voices from normal voices. Furthermore, a nonlinear tremor model is proposed to study the vibrations of the vocal folds with vocal tremor. Fractal dimensions and positive Lyapunov exponents demonstrate the evidence of chaos in the tremor model, where amplitude and frequency play important roles in governing vocal fold dynamics. Nonlinear dynamic voice analysis and vocal fold modeling may provide a useful set of tools for understanding the dynamic mechanism of vocal tremor in patients with laryngeal diseases.

Nonbinding Legal Instruments in Governance for Global Health: Lessons from the Global AIDS Reporting Mechanism.

Science.gov (United States)

Taylor, Allyn; Alfvén, Tobias; Hougendobler, Daniel; Buse, Kent

2014-01-01

Recent debate over World Health Organization reform has included unprecedented attention to international lawmaking as a future priority function of the Organization. However, the debate is largely focused on the codification of new binding legal instruments. Drawing upon lessons from the success of the Global AIDS Reporting Mechanism, established pursuant to the United Nations' Declaration of Commitment on HIV/AIDS, we argue that effective global health governance requires consideration of a broad range of instruments, both binding and nonbinding. A detailed examination of the Global AIDS Reporting Mechanism reveals that the choice of the nonbinding format makes an important contribution to its effectiveness. For instance, the flexibility and adaptability of the nonbinding format have allowed the global community to: (1) undertake commitments in a timely manner; (2) adapt and experiment in the face of a dynamic pandemic; and (3) grant civil society an unparalleled role in monitoring and reporting on state implementation of global commitments. UNAIDS' institutional support has also played a vital role in ensuring the continuing effectiveness of the Global AIDS Reporting Mechanism. Overall, the experience of the Global AIDS Reporting Mechanism evidences that, at times, nimbler nonbinding instruments can offer benefits over slower, more rigid binding legal approaches to governance, but depend critically, like all instruments, on the perceived legitimacy thereof. © 2014 American Society of Law, Medicine & Ethics, Inc.

EXTERNAL CORPORATE GOVERNANCE MECHANISMS: MERGERS AND ACQUISITIONS ON THE BRAZILIAN MARKET

Directory of Open Access Journals (Sweden)

Mario Augusto Parente Monteiro

2014-08-01

Full Text Available The research aims to answer the following question: What is the effectiveness of mergers and acquisitions in the Brazilian market as external corporate governance mechanism? The main objective of the study is to verify if mergers and acquisitions operations in Brazilian market may act as an external mechanism of corporate governance, replacing managers and, as a consequence of changes in management, improving financial performance. The study is exploratory, qualitative in its approach, supported by documentary research on secondary data concerning an intentional sample of Brazilian companies aiming to identify the effect of M&A operations on the corporate governance structure of the acquired firm and on its financial results. Data obtained on the website of the Brazilian Securities and Exchange Commission (CVM, related to Brazilian M&A operations in the period 2005-2010, were analyzed. Although M&A operations in Brazil were found to have disciplinary nature in our sample of firms in the studied period, our results are inconclusive regarding the effectiveness of these transactions and external governance mechanisms.

The Value Generating Mechanisms of Open Government Data

DEFF Research Database (Denmark)

Jetzek, Thorhildur

2013-01-01

social progress, to an interconnected, networked world of shared resources and co-creation. One of the trends driving this change is open government data. This paper presents a framework of four value generating mechanisms from use of OGD. The framework makes it easier to compare and communicate......Recent trends towards openness and technical connectivity have offered the ability to drive massive social and economic change; however they demand a redefinition of relationships. We have observed a move from a polarized world where companies operate in economic markets while governments drive...

Nonlinear modeling and dynamic analysis of hydro-turbine governing system in the process of load rejection transient

International Nuclear Information System (INIS)

Zhang, Hao; Chen, Diyi; Xu, Beibei; Wang, Feifei

2015-01-01

Graphical abstract: Nonlinear dynamic transfer coefficients are introduced to the hydro-turbine governing system. In the process of load reject ion transient, the nonlinear dynamical behaviors of the system are studied in detail. - Highlights: • A novel mathematical model of a hydro-turbine governing system is established. • The process of load rejection transient is considered. • Nonlinear dynamic transfer coefficients are introduced to the system. • The bifurcation diagram with the variable t has better engineering significance. • The nonlinear dynamical behaviors of the system are studied in detail. - Abstract: This article pays attention to the mathematical modeling of a hydro-turbine governing system in the process of load rejection transient. As a pioneer work, the nonlinear dynamic transfer coefficients are introduced in a penstock system. Considering a generator system, a turbine system and a governor system, we present a novel nonlinear dynamical model of a hydro-turbine governing system. Fortunately, for the unchanged of PID parameters, we acquire the stable regions of the governing system in the process of load rejection transient by numerical simulations. Moreover, the nonlinear dynamic behaviors of the governing system are illustrated by bifurcation diagrams, Poincare maps, time waveforms and phase orbits. More importantly, these methods and analytic results will present theoretical groundwork for allowing a hydropower station in the process of load rejection transient

Governing parameters and dynamics of turbulent spray atomization from modern GDI injectors

International Nuclear Information System (INIS)

Moon, Seoksu; Li, Tianyun; Sato, Kiyotaka; Yokohata, Hideaki

2017-01-01

Understanding the governing parameters and dynamics of turbulent spray atomization is essential for the advancement of fuel injection technologies, but no concrete understandings have been derived previously. The current study investigates the governing parameters and dynamics of turbulent spray atomization by experimental observations of near-nozzle spray phenomena using an X-ray imaging technique. The effects of critical injection parameters such as fuel property, injection pressure and ambient density on near-nozzle liquid feature size and velocity distributions were extensively studied using three injection nozzles having different levels of initial flow turbulence and dispersion. Based on the results, the governing parameters and dynamics of turbulent spray atomization and the issues on the advanced fuel injection control of modern engines were thoroughly discussed. The results showed that fuel and injection pressure effects on spray atomization became insignificant from a critical Weber number which decreased upon the increase in initial flow turbulence and dispersion. The increase in ambient density increased the resultant droplet size at downstream due to the faster deceleration of spray which brought the atomization termination location closer to the nozzle exit. The spray atomization was terminated at the location of ca. 72% exit velocity regardless of the injection condition. - Highlights: • Governing parameters and dynamics of turbulent spray atomization are investigated. • Fuel and injection pressure effects on atomization are saturated from critical We. • High ambient density increases drop sizes due to faster termination of atomization. • Atomization terminates when the spray velocity decays to ca. 72% of exit velocity. • Strategies for improvement of current injection technologies are discussed.

Mechanisms of dynamic deformation and dynamic failure in aluminum nitride

International Nuclear Information System (INIS)

Hu Guangli; Chen, C.Q.; Ramesh, K.T.; McCauley, J.W.

2012-01-01

Uniaxial quasi-static, uniaxial dynamic and confined dynamic compression experiments have been performed to characterize the failure and deformation mechanisms of a sintered polycrystalline aluminum nitride using a servohydraulic machine and a modified Kolsky bar. Scanning electron microscopy and transmission electron microscopy (TEM) are used to identify the fracture and deformation mechanisms under high rate and high pressure loading conditions. These results show that the fracture mechanisms are strong functions of confining stress and strain rate, with transgranular fracture becoming more common at high strain rates. Dynamic fracture mechanics and micromechanical models are used to analyze the observed fracture mechanisms. TEM characterization of fragments from the confined dynamic experiments shows that at higher pressures dislocation motion becomes a common dominant deformation mechanism in AlN. Prismatic slip is dominant, and pronounced microcrack–dislocation interactions are observed, suggesting that the dislocation plasticity affects the macroscopic fracture behavior in this material under high confining stresses.

Contribution to and Use of Online Knowledge Repositories: The Role of Governance Mechanisms

Science.gov (United States)

Kayhan, Varol O.

2010-01-01

Drawing upon the concept of governance, this dissertation refers to the two most commonly employed mechanisms that ensure high quality knowledge in electronic repositories as expert-governance and community-governance. In three related but distinct essays, the dissertation examines the governance concept, and investigates contributing knowledge to…

Self-trapping mechanisms in the dynamics of three coupled Bose-Einstein condensates

International Nuclear Information System (INIS)

Franzosi, Roberto; Penna, Vittorio

2002-01-01

We formulate the dynamics of three coupled Bose-Einstein condensates within a semiclassical scenario based on the standard boson coherent states. We compare such a picture with that of K. Nemoto et al. [Phys. Rev. A 63, 013604 (2001)] and show how our approach entails a simple formulation of the dimeric regime therein studied. This allows us to recognize the parameters that govern the bifurcation mechanism causing self-trapping, and paves the way to the construction of analytic solutions

Research on the Governance Mechanism of Aviation Complex Product Manufacturing Supply Chain Based on Dynamic Game Theory

Directory of Open Access Journals (Sweden)

Wang Nan

2016-01-01

Full Text Available In the manufacturing process of aeronautical complex products, for the following problems: develop long production cycle, a large number of ancillary products, a plurality of participating units, etc, and the status of the frequency of quality problems, using single-phase static game model in the case of asymmetric information, study on Supplier Quality insufficient investment, which resulting in opportunistic behaviour reasons. And using KMRW dynamic game model, we quantitative analysis the mechanism and crucial role of reputation mechanisms to ensure aeronautical complex product manufacturing supply chain and effective operation.

Nonlinear Dynamics of a PI Hydroturbine Governing System with Double Delays

OpenAIRE

Luo, Hongwei; Zhang, Jiangang; Du, Wenju; Lu, Jiarong; An, Xinlei

2017-01-01

A PI hydroturbine governing system with saturation and double delays is generated in small perturbation. The nonlinear dynamic behavior of the system is investigated. More precisely, at first, we analyze the stability and Hopf bifurcation of the PI hydroturbine governing system with double delays under the four different cases. Corresponding stability theorem and Hopf bifurcation theorem of the system are obtained at equilibrium points. And then the stability of periodic solution and the dire...

The Conformational Dynamics of Cas9 Governing DNA Cleavage Are Revealed by Single-Molecule FRET

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Mengyi Yang

2018-01-01

Full Text Available Summary: Off-target binding and cleavage by Cas9 pose major challenges in its application. How the conformational dynamics of Cas9 govern its nuclease activity under on- and off-target conditions remains largely unknown. Here, using intra-molecular single-molecule fluorescence resonance energy transfer measurements, we revealed that Cas9 in apo, sgRNA-bound, and dsDNA/sgRNA-bound forms spontaneously transits among three major conformational states, mainly reflecting significant conformational mobility of the catalytic HNH domain. We also uncovered surprising long-range allosteric communication between the HNH domain and the RNA/DNA heteroduplex at the PAM-distal end to ensure correct positioning of the catalytic site, which demonstrated that a unique proofreading mechanism served as the last checkpoint before DNA cleavage. Several Cas9 residues were likely to mediate the allosteric communication and proofreading step. Modulating interactions between Cas9 and heteroduplex at the PAM-distal end by introducing mutations on these sites provides an alternative route to improve and optimize the CRISPR/Cas9 toolbox. : Yang et al. revealed significant conformational dynamics of Cas9 at global and local scales using single-molecule FRET. They uncovered surprising long-range allosteric communication between the HNH nuclease domain and the RNA/DNA heteroduplex at the PAM-distal end that serves as a proofreading checkpoint to govern the nuclease activity and specificity of Cas9. Keywords: CRISPR, Cas9, single-molecule, FRET, conformational dynamics, proofreading, off-target, allosteric communication, genome editing

Dynamical systems in classical mechanics

CERN Document Server

Kozlov, V V

1995-01-01

This book shows that the phenomenon of integrability is related not only to Hamiltonian systems, but also to a wider variety of systems having invariant measures that often arise in nonholonomic mechanics. Each paper presents unique ideas and original approaches to various mathematical problems related to integrability, stability, and chaos in classical dynamics. Topics include… the inverse Lyapunov theorem on stability of equilibria geometrical aspects of Hamiltonian mechanics from a hydrodynamic perspective current unsolved problems in the dynamical systems approach to classical mechanics

Control mechanisms in corporate governance

Directory of Open Access Journals (Sweden)

Jovanović-Zattila Milena

2016-01-01

Full Text Available The structure of corporate governance is determined by the distribution of rights and responsibilities among different actors in the company structure. Organizationally complex structure of corporate entities, established as a reflection of composite forms of business corporations, give rise to the conflict of interest between the owners, the board of directors and managers, which is generally known as the principal-agency problem. Given the fact that operations of modern companies include interaction with a large number of stakeholders, matters of ethics and accountability to the owners, employees, creditors and the state are the basic postulates which have been subject to re-examination lately. The reasons for reassessing these issues are to be sought in numerous abuses by companies, which are on the other hand highly active in their effors to protect themselves from similar abuses (mainy cyber crime. In order to respond to new challenges and requirements, which include providing for the interests of both shareholders and stakeholders, corporate management is required to establish an adequate system of internal control covering all company activities. Contemporary trends in the development of internal audit, as a mechanism of good corporate governance, are reflected in providing advice in respect of anticipated future risks and risk management.

Dynamically Assisted Schwinger Mechanism

International Nuclear Information System (INIS)

Schuetzhold, Ralf; Gies, Holger; Dunne, Gerald

2008-01-01

We study electron-positron pair creation from the Dirac vacuum induced by a strong and slowly varying electric field (Schwinger effect) which is superimposed by a weak and rapidly changing electromagnetic field (dynamical pair creation). In the subcritical regime where both mechanisms separately are strongly suppressed, their combined impact yields a pair creation rate which is dramatically enhanced. Intuitively speaking, the strong electric field lowers the threshold for dynamical particle creation--or, alternatively, the fast electromagnetic field generates additional seeds for the Schwinger mechanism. These findings could be relevant for planned ultrahigh intensity lasers

Corporate Governance in Banks and its Impact on Risk and Performance: Review of Literature on the Selected Governance Mechanisms

Directory of Open Access Journals (Sweden)

Himaj Shkendije

2014-09-01

Full Text Available Corporate governance is viewed as an important, essential, and most significant factor for well-functioning of firms. Recent academic work and policy analyses have given insight into the governance problems in banks exposed to the financial crisis and suggest possible solutions. This paper begins by explaining the importance of corporate governance and its impact on risk taking and bank performance based on the theoretical background relevant to the corporate governance of banks. I combine the literature that looks at three areas of governance: ownership structure; board structure; and risk management, with the literature on risk-taking and performance effects in order to better assess the weight of the impact that these governance mechanisms have on both performance and risk. The paper concludes by highlighting the areas where further research is needed.

Prolonged Intracellular Na+ Dynamics Govern Electrical Activity in Accessory Olfactory Bulb Mitral Cells.

Directory of Open Access Journals (Sweden)

Asaph Zylbertal

2015-12-01

Full Text Available Persistent activity has been reported in many brain areas and is hypothesized to mediate working memory and emotional brain states and to rely upon network or biophysical feedback. Here, we demonstrate a novel mechanism by which persistent neuronal activity can be generated without feedback, relying instead on the slow removal of Na+ from neurons following bursts of activity. We show that mitral cells in the accessory olfactory bulb (AOB, which plays a major role in mammalian social behavior, may respond to a brief sensory stimulation with persistent firing. By combining electrical recordings, Ca2+ and Na+ imaging, and realistic computational modeling, we explored the mechanisms underlying the persistent activity in AOB mitral cells. We found that the exceptionally slow inward current that underlies this activity is governed by prolonged dynamics of intracellular Na+ ([Na+]i, which affects neuronal electrical activity via several pathways. Specifically, elevated dendritic [Na+]i reverses the Na+-Ca2+ exchanger activity, thus modifying the [Ca2+]i set-point. This process, which relies on ubiquitous membrane mechanisms, is likely to play a role in other neuronal types in various brain regions.

What governs governance, and how does it evolve? The sociology of governance-in-action.

Science.gov (United States)

Fox, Nick J; Ward, Katie J

2008-09-01

Governance addresses a wide range of issues including social, economic and political continuity, security and integrity, individual and collective safety and the liberty and rights to self-actualization of citizens. Questions to be answered include how governance can be achieved and sustained within a social context imbued with cultural values and in which power is distributed unevenly and dynamically, and how governance impacts on individuals and institutions. Drawing on Gramscian notions of hegemony and consent, and recent political science literatures on regulation and meta-regulation, this paper develops a sociological model of governance that emphasizes a dynamic and responsive governance in action. Empirical data from a study of pharmaceutical governance is used to show how multiple institutions and actors are involved in sustaining effective governance. The model addresses issues of how governance is sustained in the face of change, why governance of practices varies from setting to setting, and how governance is achieved without legislation.

Mechanical and dynamic mechanical behaviour of novel glass ...

Indian Academy of Sciences (India)

M Rajesh

the intra-ply woven fabric hybridization enhances impact and damping properties of the composite ... Keywords. Intra-ply hybrid; natural fibre; mechanical properties; dynamic mechanical analysis; vibration; .... analysis test is conducted in nitrogen environment over a ..... Mnson J A and Jolliet O 2001 Life cycle assessment of.

First-Principles Quantum Dynamics of Singlet Fission: Coherent versus Thermally Activated Mechanisms Governed by Molecular π Stacking

Science.gov (United States)

Tamura, Hiroyuki; Huix-Rotllant, Miquel; Burghardt, Irene; Olivier, Yoann; Beljonne, David

2015-09-01

Singlet excitons in π -stacked molecular crystals can split into two triplet excitons in a process called singlet fission that opens a route to carrier multiplication in photovoltaics. To resolve controversies about the mechanism of singlet fission, we have developed a first principles nonadiabatic quantum dynamical model that reveals the critical role of molecular stacking symmetry and provides a unified picture of coherent versus thermally activated singlet fission mechanisms in different acenes. The slip-stacked equilibrium packing structure of pentacene derivatives is found to enhance ultrafast singlet fission mediated by a coherent superexchange mechanism via higher-lying charge transfer states. By contrast, the electronic couplings for singlet fission strictly vanish at the C2 h symmetric equilibrium π stacking of rubrene. In this case, singlet fission is driven by excitations of symmetry-breaking intermolecular vibrations, rationalizing the experimentally observed temperature dependence. Design rules for optimal singlet fission materials therefore need to account for the interplay of molecular π -stacking symmetry and phonon-induced coherent or thermally activated mechanisms.

Linking governance mechanisms to health outcomes: a review of the literature in low- and middle-income countries.

Science.gov (United States)

Ciccone, Dana Karen; Vian, Taryn; Maurer, Lydia; Bradley, Elizabeth H

2014-09-01

We conducted a synthesis of peer-reviewed literature to shed light on links between governance mechanisms and health outcomes in low- and middle-income countries. Our review yielded 30 studies, highlighting four key governance mechanisms by which governance may influence health outcomes in these settings: Health system decentralization that enables responsiveness to local needs and values; health policymaking that aligns and empowers diverse stakeholders; enhanced community engagement; and strengthened social capital. Most, but not all, studies found a positive association between governance and health. Additionally, the nature of the association between governance mechanisms and health differed across studies. In some studies (N = 9), the governance effect was direct and positive, while in others (N = 5), the effect was indirect or modified by contextual factors. In still other studies (N = 4), governance was found to have a moderating effect, indicating that governance mechanisms influenced other system processes or structures that improved health. The remaining studies reported mixed findings about the association between governance and health (N = 6), no association between governance and health (N = 4), or had inconclusive results (N = 2). Further exploration is needed to fully understand the relationship between governance and health and to inform the design and delivery of evidence-based, effective governance interventions around the world. Copyright © 2014 Elsevier Ltd. All rights reserved.

Diffusive, Displacive Deformations and Local Phase Transformation Govern the Mechanics of Layered Crystals: The Case Study of Tobermorite.

Science.gov (United States)

Tao, Lei; Shahsavari, Rouzbeh

2017-07-19

Understanding the deformation mechanisms underlying the mechanical behavior of materials is the key to fundamental and engineering advances in materials' performance. Herein, we focus on crystalline calcium-silicate-hydrates (C-S-H) as a model system with applications in cementitious materials, bone-tissue engineering, drug delivery and refractory materials, and use molecular dynamics simulation to investigate its loading geometry dependent mechanical properties. By comparing various conventional (e.g. shear, compression and tension) and nano-indentation loading geometries, our findings demonstrate that the former loading leads to size-independent mechanical properties while the latter results in size-dependent mechanical properties at the nanometer scales. We found three key mechanisms govern the deformation and thus mechanics of the layered C-S-H: diffusive-controlled and displacive-controlled deformation mechanisms, and strain gradient with local phase transformations. Together, these elaborately classified mechanisms provide deep fundamental understanding and new insights on the relationship between the macro-scale mechanical properties and underlying molecular deformations, providing new opportunities to control and tune the mechanics of layered crystals and other complex materials such as glassy C-S-H, natural composite structures, and manmade laminated structures.

Dynamics analysis of the fast-slow hydro-turbine governing system with different time-scale coupling

Science.gov (United States)

Zhang, Hao; Chen, Diyi; Wu, Changzhi; Wang, Xiangyu

2018-01-01

Multi-time scales modeling of hydro-turbine governing system is crucial in precise modeling of hydropower plant and provides support for the stability analysis of the system. Considering the inertia and response time of the hydraulic servo system, the hydro-turbine governing system is transformed into the fast-slow hydro-turbine governing system. The effects of the time-scale on the dynamical behavior of the system are analyzed and the fast-slow dynamical behaviors of the system are investigated with different time-scale. Furthermore, the theoretical analysis of the stable regions is presented. The influences of the time-scale on the stable region are analyzed by simulation. The simulation results prove the correctness of the theoretical analysis. More importantly, the methods and results of this paper provide a perspective to multi-time scales modeling of hydro-turbine governing system and contribute to the optimization analysis and control of the system.

Cold pressure welding - the mechanisms governing bonding

DEFF Research Database (Denmark)

Bay, Niels

1979-01-01

Investigations of the bonding surface in scanning electron microscope after fracture confirm the mechanisms of bond formation in cold pressure welding to be: fracture of work-hardened surface layer, surface expansion increasing the area of virgin surface, extrusion of virgin material through cracks...... of the original surface layer, and establishment of real contact and bonding between virgin material. This implies that normal pressure as well as surface expansion are basic parameters governing the bond strength. Experimental investigations of pressure welding Al-Al under plane strain compression in a specially...

Peri-dynamics

International Nuclear Information System (INIS)

Littlewood, D.

2015-01-01

Peri-dynamics, a nonlocal extension of continuum mechanics, is a natural framework for capturing constitutive response and modelling pervasive material failure and fracture. Unlike classical approaches incorporating partial derivatives, the peri-dynamic governing equations utilise integral expressions that remain valid in the presence of discontinuities such as cracks. The mathematical theory of peri-dynamics unifies the mechanics of continuous media, cracks, and discrete particles. The result is a consistent framework for capturing a wide range of constitutive responses, including inelasticity, in combination with robust material failure laws. Peri-dynamics has been implemented in a number of computational simulation codes, including the open source code Peridigm and the Sierra/SolidMechanics analysis code at Sandia National Laboratories. (author)

Uncovering governance mechanisms surrounding harbour porpoise conservation in the Danish Skagerrak Sea

DEFF Research Database (Denmark)

Sørensen, Thomas Kirk; Kindt-Larsen, Lotte

2016-01-01

mainly by the economy and the varying perceptions of the bycatch issue, with great differences between government, NGO's and fishers. Interviews with fishers and fishing effort data reveal intra-sectoral conflicts pertaining to the incompatibility of active trawling and passive gillnetting in the areas......The harbour porpoise (Phocoena phocoena) is the focus of a range of conservation efforts and policies, including the Habitats Directive, aimed at reducing the bycatch of non-target species in gillnet fisheries. This paper describes the governance process and analyses the governance mechanisms...

Direct observation of TALE protein dynamics reveals a two-state search mechanism.

Science.gov (United States)

Cuculis, Luke; Abil, Zhanar; Zhao, Huimin; Schroeder, Charles M

2015-06-01

Transcription activator-like effector (TALE) proteins are a class of programmable DNA-binding proteins for which the fundamental mechanisms governing the search process are not fully understood. Here we use single-molecule techniques to directly observe TALE search dynamics along DNA templates. We find that TALE proteins are capable of rapid diffusion along DNA using a combination of sliding and hopping behaviour, which suggests that the TALE search process is governed in part by facilitated diffusion. We also observe that TALE proteins exhibit two distinct modes of action during the search process-a search state and a recognition state-facilitated by different subdomains in monomeric TALE proteins. Using TALE truncation mutants, we further demonstrate that the N-terminal region of TALEs is required for the initial non-specific binding and subsequent rapid search along DNA, whereas the central repeat domain is required for transitioning into the site-specific recognition state.

Mekanisme Corporate Governance dan Kecurangan Laporan Keuangan [Mechanisms of Corporate Governance and Financial Statement Fraud

Directory of Open Access Journals (Sweden)

Fitri Ismiyanti

2015-09-01

Full Text Available The purpose of this research is to examine factors that may affect fraud on financial statements that could encourage the emergence of corruption by management. This research uses banks as an industry sample because the banking industry is highly regulated and should report their financial statement to a central bank. Meanwhile, banks still frequently have fraudulent financial statements. Good corporate governance mechanisms indicated that banks have the capability to detect fraud in financial statements. This research focuses on testing factors that may affect the financial statements fraud which lead to the corruption of management. The data used in this research is financial statement data. Corporate governance mechanisms tested in this study are the number of commissioners, percentage of independent directors, number of commissioners meeting, percentage of largest share ownership, managerial ownership, long tenure of commissioners, and type of auditor. This research found that the number of commissioners and managerial ownership affects management's fraud, while the number of independent directors, the number of commissioners meeting, a long tenure managing director, large share ownership, and the type of auditor has no effect on fraud.

Dynamics of ligand exchange mechanism at Cu(II) in water: an ab initio quantum mechanical charge field molecular dynamics study with extended quantum mechanical region.

Science.gov (United States)

Moin, Syed Tarique; Hofer, Thomas S; Weiss, Alexander K H; Rode, Bernd M

2013-07-07

Ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) were successfully applied to Cu(II) embedded in water to elucidate structure and to understand dynamics of ligand exchange mechanism. From the simulation studies, it was found that using an extended large quantum mechanical region including two shells of hydration is required for a better description of the dynamics of exchanging water molecules. The structural features characterized by radial distribution function, angular distribution function and other analytical parameters were consistent with experimental data. The major outcome of this study was the dynamics of exchange mechanism and reactions in the first hydration shell that could not be studied so far. The dynamical data such as mean residence time of the first shell water molecules and other relevant data from the simulations are close to the results determined experimentally. Another major characteristic of hydrated Cu(II) is the Jahn-Teller distortion which was also successfully reproduced, leading to the final conclusion that the dominating aqua complex is a 6-coordinated species. The ab initio QMCF-MD formalism proved again its capabilities of unraveling even ambiguous properties of hydrated species that are far difficult to explore by any conventional quantum mechanics/molecular mechanics (QM/MM) approach or experiment.

Dynamics of ligand exchange mechanism at Cu(II) in water: An ab initio quantum mechanical charge field molecular dynamics study with extended quantum mechanical region

International Nuclear Information System (INIS)

Moin, Syed Tarique; Hofer, Thomas S.; Weiss, Alexander K. H.; Rode, Bernd M.

2013-01-01

Ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) were successfully applied to Cu(II) embedded in water to elucidate structure and to understand dynamics of ligand exchange mechanism. From the simulation studies, it was found that using an extended large quantum mechanical region including two shells of hydration is required for a better description of the dynamics of exchanging water molecules. The structural features characterized by radial distribution function, angular distribution function and other analytical parameters were consistent with experimental data. The major outcome of this study was the dynamics of exchange mechanism and reactions in the first hydration shell that could not be studied so far. The dynamical data such as mean residence time of the first shell water molecules and other relevant data from the simulations are close to the results determined experimentally. Another major characteristic of hydrated Cu(II) is the Jahn-Teller distortion which was also successfully reproduced, leading to the final conclusion that the dominating aqua complex is a 6-coordinated species. The ab initio QMCF-MD formalism proved again its capabilities of unraveling even ambiguous properties of hydrated species that are far difficult to explore by any conventional quantum mechanics/molecular mechanics (QM/MM) approach or experiment

Interaction effects between internal governance mechanisms on the components of initial returns during the IPO

Directory of Open Access Journals (Sweden)

Mediha Mezhoud

2012-12-01

Full Text Available Our work provides an analysis of the interaction effects between internal governance mechanisms on the components of initial returns during the listing period. The application of multivariate regressions on a sample of 110 IPO French companies during 2005-2010, has allowed us to conclude that the different interactions between these mechanisms significantly influence the level of under / overpricing. Indeed, the positive relationship between internal governance mechanisms and overpricing reflects a substitutability relationship. In contrast, the complementarity effect comes from the negative relationship characterizing the combination of governance mechanisms and the underpricing. Thus, the interactions effects between institutional ownership, board structure and under / overpricing are not conforming to the existence of a complementarity or substitutability relationship between these variables given the absence of a significant combination between these variables

Dynamics of mechanical systems with variable mass

CERN Document Server

Belyaev, Alexander

2014-01-01

The book presents up-to-date and unifying formulations for treating dynamics of different types of mechanical systems with variable mass. The starting point is overview of the continuum mechanics relations of balance and jump for open systems from which extended Lagrange and Hamiltonian formulations are derived. Corresponding approaches are stated at the level of analytical mechanics with emphasis on systems with a position-dependent mass and at the level of structural mechanics. Special emphasis is laid upon axially moving structures like belts and chains, and on pipes with an axial flow of fluid. Constitutive relations in the dynamics of systems with variable mass are studied with particular reference to modeling of multi-component mixtures. The dynamics of machines with a variable mass are treated in detail and conservation laws and the stability of motion will be analyzed. Novel finite element formulations for open systems in coupled fluid and structural dynamics are presented.

Transforming Government Service

DEFF Research Database (Denmark)

Pedersen, Keld

2017-01-01

The Danish government has defined an ambitious e-government strategy aiming to increase both citizen centricity and the efficiency of government service production and delivery. This research uses dynamic capability theory to compare a highly successful and a less successful e-government program...... both aiming at realizing this strategy by reengineering back office processes and implement one-stop shopping. The research contributes to the e-government literature by identifying key differences between the two cases in terms of dynamic capabilities, by identifying the importance...

Numerical methods in dynamic fracture mechanics

International Nuclear Information System (INIS)

Beskos, D.E.

1987-01-01

A review of numerical methods for the solution of dynamic problems of fracture mechanics is presented. Finite difference, finite element and boundary element methods as applied to linear elastic or viscoelastic and non-linear elastoplastic or elastoviscoplastic dynamic fracture mechanics problems are described and critically evaluated. Both cases of stationary cracks and rapidly propagating cracks of simple I, II, III or mixed modes are considered. Harmonically varying with time or general transient dynamic disturbances in the form of external loading or incident waves are taken into account. Determination of the dynamic stress intensity factor for stationary cracks or moving cracks with known velocity history as well as determination of the crack-tip propagation history for given dynamic fracture toughness versus crack velocity relation are described and illustrated by means of certain representative examples. Finally, a brief assessment of the present state of knowledge is made and research needs are identified

Structural fluctuation governed dynamic diradical character in pentacene.

Science.gov (United States)

Yang, Hongfang; Chen, Mengzhen; Song, Xinyu; Bu, Yuxiang

2015-06-07

We unravel intriguing dynamical diradical behavior governed by structural fluctuation in pentacene using ab initio molecular dynamics simulation. In contrast to static equilibrium configuration of pentacene with a closed-shell ground state without diradical character, due to structural fluctuation, some of its dynamical snapshot configurations exhibit an open-shell broken-symmetry singlet ground state with diradical character, and such diradical character presents irregular pulsing behavior in time evolution. Not all structural changes can lead to diradical character, only those involving the shortening of cross-linking C-C bonds and variations of the C-C bonds in polyacetylene chains are the main contributors. This scenario about diradicalization is distinctly different from that in long acenes. The essence is that structural distortion cooperatively raises the HOMO and lowers the LUMO, efficiently reducing the HOMO-LUMO and singlet-triplet energy gaps, which facilitate the formation of a broken-symmetry open-shell singlet state. The irregular pulsing behavior originates from the mixing of normal vibrations in pentacene. This fascinating behavior suggests the potential application of pentacene as a suitable building block in the design of new electronic devices due to its magnetism-controllability through energy induction. This work provides new insight into inherent electronic property fluctuation in acenes.

Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties

International Nuclear Information System (INIS)

Strikman, Mark; Weiss, Christian

2009-01-01

We summarize our understanding of the dynamical mechanisms governing rapidity gap survival in central exclusive diffraction, pp -> p + H + p (H = high-mass system), and discuss the uncertainties in present estimates of the survival probability. The main suppression of diffractive scattering is due to inelastic soft spectator interactions at small pp impact parameters and can be described in a mean-field approximation (independent hard and soft interactions). Moderate extra suppression results from fluctuations of the partonic configurations of the colliding protons. At LHC energies absorptive interactions of hard spectator partons associated with the gg -> H process reach the black-disk regime and cause substantial additional suppression, pushing the survival probability below 0.01.

Family controlled firm, governance mechanisms and corporate performance: Evidence from Indonesia

Directory of Open Access Journals (Sweden)

Eko Suyono

2016-07-01

Full Text Available This study investigates, firstly, the influence of family-controlled firm on corporate performance, and secondly, the influences of corporate governance mechanisms including control variable on corporate performance in the companies listed on the Indonesian Stock Exchange. By using five years (2009-2013 company data, this study used Ordinary Least Square (OLS regression to test the hypotheses. The results based on OLS, indicate that family controlled firms tend to have better performance than non Family controlled firms. Moreover, in regard to the link between governance variables and corporate performance, only managerial ownership exhibits a positive relation with corporate performance, for both proxies, i.e. Tobins Q and ROA. Yet, the rests of governance variables (i.e. institutional ownership, audit committee, board of directors and independent board of commissioners do not confirm the relationship with corporate performance. These findings have significant policy implications for the government, regulatory bodies, companies and other stakeholders including the investors in Indonesia to shape and implement an optimal governance system that can improve corporate performance.

Dimensionless study on dynamics of pressure controlled mechanical ventilation system

International Nuclear Information System (INIS)

Shi, Yan; Niu, Jinglong; Cai, Maolin; Xu, Weiqing

2015-01-01

Dynamics of mechanical ventilation system can be referred in pulmonary diagnostics and treatments. In this paper, to conveniently grasp the essential characteristics of mechanical ventilation system, a dimensionless model of mechanical ventilation system is presented. For the validation of the mathematical model, a prototype mechanical ventilation system of a lung simulator is proposed. Through the simulation and experimental studies on the dimensionless dynamics of the mechanical ventilation system, firstly, the mathematical model is proved to be authentic and reliable. Secondly, the dimensionless dynamics of the mechanical ventilation system are obtained. Last, the influences of key parameters on the dimensionless dynamics of the mechanical ventilation system are illustrated. The study provides a novel method to study the dynamic of mechanical ventilation system, which can be referred in the respiratory diagnostics and treatment.

Dimensionless study on dynamics of pressure controlled mechanical ventilation system

Energy Technology Data Exchange (ETDEWEB)

Shi, Yan; Niu, Jinglong; Cai, Maolin; Xu, Weiqing [Beihang University, Beijing (Korea, Republic of)

2015-02-15

Dynamics of mechanical ventilation system can be referred in pulmonary diagnostics and treatments. In this paper, to conveniently grasp the essential characteristics of mechanical ventilation system, a dimensionless model of mechanical ventilation system is presented. For the validation of the mathematical model, a prototype mechanical ventilation system of a lung simulator is proposed. Through the simulation and experimental studies on the dimensionless dynamics of the mechanical ventilation system, firstly, the mathematical model is proved to be authentic and reliable. Secondly, the dimensionless dynamics of the mechanical ventilation system are obtained. Last, the influences of key parameters on the dimensionless dynamics of the mechanical ventilation system are illustrated. The study provides a novel method to study the dynamic of mechanical ventilation system, which can be referred in the respiratory diagnostics and treatment.

Zeno dynamics in quantum statistical mechanics

International Nuclear Information System (INIS)

Schmidt, Andreas U

2003-01-01

We study the quantum Zeno effect in quantum statistical mechanics within the operator algebraic framework. We formulate a condition for the appearance of the effect in W*-dynamical systems, in terms of the short-time behaviour of the dynamics. Examples of quantum spin systems show that this condition can be effectively applied to quantum statistical mechanical models. Furthermore, we derive an explicit form of the Zeno generator, and use it to construct Gibbs equilibrium states for the Zeno dynamics. As a concrete example, we consider the X-Y model, for which we show that a frequent measurement at a microscopic level, e.g. a single lattice site, can produce a macroscopic effect in changing the global equilibrium

Nonlinear Dynamic Phenomena in Mechanics

CERN Document Server

Warminski, Jerzy; Cartmell, Matthew P

2012-01-01

Nonlinear phenomena should play a crucial role in the design and control of engineering systems and structures as they can drastically change the prevailing dynamical responses. This book covers theoretical and applications-based problems of nonlinear dynamics concerned with both discrete and continuous systems of interest in civil and mechanical engineering. They include pendulum-like systems, slender footbridges, shape memory alloys, sagged elastic cables and non-smooth problems. Pendulums can be used as a dynamic absorber mounted in high buildings, bridges or chimneys. Geometrical nonlinear

Governance mechanisms for healthcare apps

DEFF Research Database (Denmark)

Manikas, Konstantinos; Hansen, Klaus Marius; Kyng, Morten

2014-01-01

The introduction of the `app store' concept has challenged the way software is distributed and marketed: developers have easier access to customers, while customers have easy access to innovative applications. Apps today are increasingly focusing on more "mission-critical" areas like healthcare...... with the Apple AppStore counting more than 40,000 apps under the category "health & fitness". This rapid development of healthcare apps increases the necessity of governance as, currently, healthcare apps are not thoroughly governed. The U.S. Food and Drug Administration and the European Commission only have...... policies for apps that are medical devices.In this paper, we approach the problem of how to govern healthcare and medical apps by addressing the risks the use of these apps pose, while at the same time inviting for development of new apps. To do so we (i) analyze four cases of healthcare app governance...

Promoting the Sustainable Building Market: an Evolution Analysis and System Dynamics Simulation on Behaviors of Real Estate Developers and Government

Directory of Open Access Journals (Sweden)

Xiuli Xie

2014-05-01

Full Text Available Purpose: The Chinese government takes measures to promote the development of green building (GB. But until 2013, there are only few green buildings in China. The real estate developers are skeptical in entering GB market, which requires theories to explain developers and government’s behaviors.Design/methodology/approach: In this study, we attempt Evolutionary game theory and System dynamics (SD into the analysis. A system dynamics model is built for studying evolutionary games between the government and developers in greening building decision making.Findings and Originality/value: The results of mixed-strategy stability analysis and SD simulation show that evolutionary equilibrium does not exist with a static government incentive. Therefore, a dynamical incentive is suggested in the SD model for promoting the green building market. The symmetric game and asymmetric game between two developers show, if the primary proportion who choose GB strategy is lower, all the group in game may finally evolve to GB strategy. In this case and in this time, the government should take measures to encourage developers to enter into the GB market. If the proportion who choose GB strategy is high enough, the government should gradually cancel or reduce those incentive measure.Research limitations/implications: an Evolution Analysis and System Dynamics Simulation on Behaviors of Real Estate Developers and Government could give some advice for the government to promote the green building market.

Nonlinear structural mechanics theory, dynamical phenomena and modeling

CERN Document Server

Lacarbonara, Walter

2013-01-01

Nonlinear Structural Mechanics: Theory, Dynamical Phenomena and Modeling offers a concise, coherent presentation of the theoretical framework of nonlinear structural mechanics, computational methods, applications, parametric investigations of nonlinear phenomena and their mechanical interpretation towards design. The theoretical and computational tools that enable the formulation, solution, and interpretation of nonlinear structures are presented in a systematic fashion so as to gradually attain an increasing level of complexity of structural behaviors, under the prevailing assumptions on the geometry of deformation, the constitutive aspects and the loading scenarios. Readers will find a treatment of the foundations of nonlinear structural mechanics towards advanced reduced models, unified with modern computational tools in the framework of the prominent nonlinear structural dynamic phenomena while tackling both the mathematical and applied sciences. Nonlinear Structural Mechanics: Theory, Dynamical Phenomena...

Modulation of neuronal dynamic range using two different adaptation mechanisms

Directory of Open Access Journals (Sweden)

Lei Wang

2017-01-01

Full Text Available The capability of neurons to discriminate between intensity of external stimulus is measured by its dynamic range. A larger dynamic range indicates a greater probability of neuronal survival. In this study, the potential roles of adaptation mechanisms (ion currents in modulating neuronal dynamic range were numerically investigated. Based on the adaptive exponential integrate-and-fire model, which includes two different adaptation mechanisms, i.e. subthreshold and suprathreshold (spike-triggered adaptation, our results reveal that the two adaptation mechanisms exhibit rather different roles in regulating neuronal dynamic range. Specifically, subthreshold adaptation acts as a negative factor that observably decreases the neuronal dynamic range, while suprathreshold adaptation has little influence on the neuronal dynamic range. Moreover, when stochastic noise was introduced into the adaptation mechanisms, the dynamic range was apparently enhanced, regardless of what state the neuron was in, e.g. adaptive or non-adaptive. Our model results suggested that the neuronal dynamic range can be differentially modulated by different adaptation mechanisms. Additionally, noise was a non-ignorable factor, which could effectively modulate the neuronal dynamic range.

Quantum mechanics and dynamics in phase space

International Nuclear Information System (INIS)

Zlatev, I.S.

1979-01-01

Attention is paid to formal similarity of quantum mechanics and classical statistical physics. It is supposed that quantum mechanics can be reformulated by means of the quasiprobabilistic distributions (QPD). The procedure of finding a possible dynamics of representative points in a phase space is described. This procedure would lead to an equation of the Liouville type for the given QPD. It is shown that there is always a dynamics for which the phase volume is preserved and there is another dynamics for which the equations of motion are ''canonical''. It follows from the paper that in terms of the QPD the quantum mechanics is analogous to the classical statistical mechanics and it can be interpreted as statistics of phase points, their motion obeying the canonical equations. The difference consists in the fact that in the classical statistical physics constructed is statistics of points in a phase space which depict real, existing, observable states of the system under consideration. In the quantum mechanics constructed is statistics of points in a phase space which correspond to the ''substrate'' of quantum-mechanical objects which have no any physical sense and cannot be observed separately

Project governance: selected South African government experiments

Directory of Open Access Journals (Sweden)

G. van der Walt

2008-07-01

Full Text Available Some form of accountability and power structure binds all organisations. Such structures are typically referred to as the “governance” structure of the organisation. In organisations that have relatively mature project applications and methodologies in place, governance mechanisms are established on more permanent bases. With its focus on performance, results and outcomes, project governance establishes decision-making structures, as well as accountability and responsibility mechanisms in public institutions to oversee projects. As government institutions increasingly place emphasis on project applications for policy implementation and service delivery initiatives, mechanisms or structures should be established to facilitate clear interfaces between the permanent organisation and the temporary project organisation. Such mechanisms or structures should enhance the governance of projects, that is, the strategic alignment of projects, the decentralisation of decision- making powers, rapid resource allocation, and the participation of external stakeholders. The purpose of this article is to explore the concept “project governance”, and to highlight examples of project governance as applied in selected government departments in provincial and national spheres. This would enable the establishment of best practice examples and assist to develop benchmarks for effective project applications for service delivery improvement.

Corporate governance, accountability and mechanisms of accountability : an overview

OpenAIRE

Brennan, Niamh; Solomon, J. (Jill)

2008-01-01

Purpose – This paper reviews traditional corporate governance and accountability research, to suggest opportunities for future research in this field. The first part adopts an analytical frame of reference based on theory, accountability mechanisms, methodology, business sector/context, globalisation and time horizon. The second part of the paper locates the seven papers in the special issue in a framework of analysis showing how each one contributes to the field. The paper presents a frame o...

Network governance and capacity of local governments to deliver LED in Uganda

Directory of Open Access Journals (Sweden)

Rose B Namara

2016-02-01

Full Text Available This paper discusses network governance and its contribution to the capacity of local governments (LGs to deliver local economic development (LED in Uganda. Although a formal LED policy was only established in Uganda in February 2014, there have been LED-inspired practices in the past decade. Various scholars and practitioners have observed that the autonomy and capacity of LGs to deliver LED is limited, but have been hopeful that new governance strategies like network governance would increase the capacities of LGs. However, neither network governance arrangements among LGs, nor their potential to improve governance capacity, have been documented. In a case study of Kyenjojo District, this paper finds that existing network governance arrangements have been fundamental in improving financial autonomy at this LG, delivering some income to invest in LED activities, although no evidence was found of reduced transaction costs in transforming local economies. The study further reveals that network governance arrangements have not led to the development of specialised skills in regulation or law enforcement, and capacity gaps are evident amongst staff and members in understanding the private sector and how it works. On a positive note, there is clear evidence of attempts by the LG to be innovative. Based on these findings, this study recommends that LGs need to consider a multi-pronged or multi-network governance approach to LED, which in turn will require a refocusing of governance mechanisms to become more dynamic and responsive, and offer incentives to the various actors in the development sector.

Governance mechanisms, investment opportunity set and SMEs cash holdings

OpenAIRE

Belghitar, Yacine; Khan, James

2013-01-01

This study analyses the effect of firm characteristics and governance mechanisms on cash holdings for a sample of UK SMEs. The results show that UK SMEs with greater cash flow volatility and institutional investors hold more cash; whereas levered and dividend paying SMEs with non-executive ownership hold less cash. We also find that ownership structure is significant only in explaining the cash holdings for firms with high growth investment opportunities, and leverage is only significant in e...

Dynamic mechanical behaviors of Fangshan marble

Directory of Open Access Journals (Sweden)

Wei Yao

2017-10-01

Full Text Available Dynamic strength parameters are extensively used in mining engineering and rock mechanics. However, there are no widely accepted dynamic failure models for rocks. In this study, the dynamic punching shear strength, uniaxial compressive strength (UCS and tensile strength of fine-grained Fangshan marble (FM are first measured by using a split Hopkinson pressure bar (SHPB system. The pulse-shaping technique is then implemented to maintain the dynamic force balance in SHPB tests. Experimental results show that the dynamic punching shear strength, UCS and tensile strength increase with the loading rate. A recently developed dynamic Mohr-Coulomb theory is then used to interpret the testing data. In this model, the angle of internal friction ϕ is assumed to be independent of loading rate and is obtained using the static strength values. According to the dynamic Mohr-Coulomb theory, the dynamic UCS and the dynamic tensile strength are predicted from the dynamic punching shear strength. Furthermore, based on this dynamic theory, the dynamic UCS is predicted from the dynamic tensile strength. The consistency between the predicted and measured dynamic strengths demonstrates that the dynamic Mohr-Coulomb theory is applicable to FM.

GOVERNANCE FROM BELOW A Theory of Local Government With Two Empirical Tests

OpenAIRE

Jean-Paul Faguet

2005-01-01

I examine decentralization through the lens of the local dynamics that it unleashes. The national effects of decentralization are simply the sum of its local-level effects. Hence to understand decentralization we must first understand how local government works. This paper proposes a theory of local government as the confluence of two quasi-markets and one organizational dynamic. Good government results when these three elements - political, economic and civil - are in rough balance, and acto...

Dynamic relationships between oil revenue, government spending and economic growth in Oman

Directory of Open Access Journals (Sweden)

Ahmad Hassan Ahmad

2015-07-01

Full Text Available This paper investigates the short-run and long-run relationships between three main macroeconomic variables in Oman using the Johansen multivariate co-integration techniques as well as the stationary VAR for the period between 1971 and 2013. The results indicate that there is a long-run relationship between these three macroeconomic variables; the real GDP, the real government expenditure and the real oil revenues. The estimated coefficients for the real oil revenues and the real government expenditure are correctly signed and statistically significant at 5% level. Both variables depict positive relationship with GDP which are 0.672 and 0.872 respectively. The impulse response functions and the variance decomposition from the stationary VAR show that these variables are very important to the short-run dynamics of the Omani economy. Overall, government expenditure appears to be the main source for economic growth in long-run, and in short run variations in government expenditure are generally derived by oil revenue shocks. Therefore, the volatility in oil revenue requires public expenditure management reforms and the need to diversify income sources in order to enhance economic stability and growth.

Mechanical Cushion Design Influence on Cylinder Dynamics

DEFF Research Database (Denmark)

Borghi, Massimo; Milani, Massimo; Conrad, Finn

2005-01-01

The paper deals with the simulation and the experimental verification of the dynamic behaviour of a linear actuator equipped with different configurations of mechanical cushion. A numerical model, developed and tailored to describe the influence of different modulation of the discharged flow....... experimental comparison, involving the piston velocity and the cylinder chambers pressure. After, with the aim of highlighting the effect of mechanical cushions design on a two effect linear actuator dynamic performances, the characteristics modulation of four alternative cushioning systems are determined...

The Influence of Corporate Governance Mechanism on the Relationship between Related Party Transactions and Earnings Management

Directory of Open Access Journals (Sweden)

Aria Farah Mita

2014-04-01

Full Text Available The objective of this study is to investigate the relationship between related party transactions (RPT and earnings management. This study argues there is a different influence between RPT a priori likely to result in expropriation and RPT a priori not likely to result in expropriation. RPT a priori likely to result in expropriation creates an incentive to management or controlling shareholder to overstate income to cover or mask their expropriation. This study uses non-absolute discretionary accruals based on Kazsnik model to proxy earnings management. Corporate governance mechanism should reduce the incentive to overstate income in a company that involves in RPT a priori likely to result in expropriation. The results of this study show that the earnings management (income increasing is affected by the existence of RPT a priori likely to result in expropriation and corporate governance mechanism, but it is not affected by the size/value of the transactions. As expected, companies involving in RPT a priori likely to result in expropriation with weak corporate governance mechanism, tend to manage earnings that increase income. We find that strong corporate governance mechanism decreases the discretionary accruals in companies which have RPT a priori likely to result in expropriation.

Controlling Hydrogel Mechanics via Bio-Inspired Polymer-Nanoparticle Bond Dynamics.

Science.gov (United States)

Li, Qiaochu; Barrett, Devin G; Messersmith, Phillip B; Holten-Andersen, Niels

2016-01-26

Interactions between polymer molecules and inorganic nanoparticles can play a dominant role in nanocomposite material mechanics, yet control of such interfacial interaction dynamics remains a significant challenge particularly in water. This study presents insights on how to engineer hydrogel material mechanics via nanoparticle interface-controlled cross-link dynamics. Inspired by the adhesive chemistry in mussel threads, we have incorporated iron oxide nanoparticles (Fe3O4 NPs) into a catechol-modified polymer network to obtain hydrogels cross-linked via reversible metal-coordination bonds at Fe3O4 NP surfaces. Unique material mechanics result from the supra-molecular cross-link structure dynamics in the gels; in contrast to the previously reported fluid-like dynamics of transient catechol-Fe(3+) cross-links, the catechol-Fe3O4 NP structures provide solid-like yet reversible hydrogel mechanics. The structurally controlled hierarchical mechanics presented here suggest how to develop hydrogels with remote-controlled self-healing dynamics.

Rigid body dynamics of mechanisms

CERN Document Server

Hahn, Hubert

2003-01-01

The second volume of Rigid Body Dynamics of Mechanisms covers applications via a systematic method for deriving model equations of planar and spatial mechanisms. The necessary theoretical foundations have been laid in the first volume that introduces the theoretical mechanical aspects of mechatronic systems. Here the focus is on the application of the modeling methodology to various examples of rigid-body mechanisms, simple planar ones as well as more challenging spatial problems. A rich variety of joint models, active constraints, plus active and passive force elements is treated. The book is intended for self-study by working engineers and students concerned with the control of mechanical systems, i.e. robotics, mechatronics, vehicles, and machine tools. The examples included are a likely source from which to choose models for university lectures.

'Good Governance' dan 'Governability'

Directory of Open Access Journals (Sweden)

- Pratikno

2005-03-01

Full Text Available The article endeavors to trace the outset of governance concept, its dominant meanings and discourse, and its implication towards governability. The central role of government in the governing processes has predominantly been adopted. The concept of governance was emerged precisely in the context of the failure of government as key player in regulation, economic redistribution and political participation. Governance is therefore aimed to emphasize pattern of governing which are based both on democratic mechanism and sound development management. However, practices of such good governance concept –which are mainly adopted and promoted by donor states and agencies– tend to degrade state and/or government authority and legitimacy. Traditional function of the state as sole facilitator of equal societal, political and legal membership among citizens has been diminished. The logic of fair competition has been substituted almost completely by the logic of free competition in nearly all sectors of public life. The concept and practices of good governance have resulted in decayed state authority and failed state which in turn created a condition for "ungovernability". By promoting democratic and humane governance, the article accordingly encourages discourse to reinstall and bring the idea of accountable state back in.

Adaptive governance of the Baltic Sea - lessons from elsewhere

Directory of Open Access Journals (Sweden)

Matilda Valman

2015-03-01

Full Text Available Governance of marine resources is increasingly characterized by integrated, cross sectoral and ecosystem based approaches. Such approaches require that existing governing bodies have an ability to adapt to ecosystem dynamics, while also providing transparent and legitimate outcomes. Here, we investigate how the Baltic Marine Environment Protection Commission (HELCOM, the international governing body for the Baltic Sea, could improve its prospects for working with the ecosystem approach, drawing from the literature on adaptive governance. We construct an ideal type of adaptive governance to which we compare the way in which HELCOM is operating and relate these dynamics to two other international marine environment governance organizations, the Coral Triangle Initiative on Coral Reefs, Fisheries and Food Security (CTI-CFF and the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR. We conclude that HELCOM deviates from an ideal type of adaptive governance in several ways but also that the other two case studies provide empirical support for potential ways in which HELCOM could improve its adaptive capacity. Key aspects where HELCOM could improve include increasing stakeholder participation – both in information sharing and decision making. Further, HELCOM need to develop evaluation mechanisms, secure compliance to improve adaptive capacity and organizational effectiveness, which entails the development of structures for conflict resolution. Finally, HELCOM need to increase communication and harmonization between different levels of authority.

Nonlinear Dynamics of a PI Hydroturbine Governing System with Double Delays

Directory of Open Access Journals (Sweden)

Hongwei Luo

2017-01-01

Full Text Available A PI hydroturbine governing system with saturation and double delays is generated in small perturbation. The nonlinear dynamic behavior of the system is investigated. More precisely, at first, we analyze the stability and Hopf bifurcation of the PI hydroturbine governing system with double delays under the four different cases. Corresponding stability theorem and Hopf bifurcation theorem of the system are obtained at equilibrium points. And then the stability of periodic solution and the direction of the Hopf bifurcation are illustrated by using the normal form method and center manifold theorem. We find out that the stability and direction of the Hopf bifurcation are determined by three parameters. The results have great realistic significance to guarantee the power system frequency stability and improve the stability of the hydropower system. At last, some numerical examples are given to verify the correctness of the theoretical results.

Gaps in governance: protective mechanisms used by nurse leaders when policy and practice are misaligned.

Science.gov (United States)

Knight, Kaye M; Kenny, Amanda; Endacott, Ruth

2015-04-09

Due to large geographical distances, the telephone is central to enabling rural Australian communities to access care from their local health service. While there is a history of rural nurses providing care via the telephone, it has been a highly controversial practice that is not routinely documented and little is known about how the practice is governed. The lack of knowledge regarding governance extends to the role of Directors of Nursing as clinical leaders charged with the responsibility of ensuring practice safety, quality, regulation and risk management. The purpose of this study was to identify clinical governance processes related to managing telephone presentations, and to explore Directors of Nursing perceptions of processes and clinical practices related to the management of telephone presentations to health services in rural Victoria, Australia. Qualitative documentary analysis and semi structured interviews were used in the study to examine the content of health service policies and explore the perceptions of Directors of Nursing in eight rural health services regarding policy content and enactment when people telephone rural health services for care. Participants were purposively selected for their knowledge and leadership role in governance processes and clinical practice. Data from the interviews were analysed using framework analysis. The process of analysis resulted in the identification of five themes. The majority of policies reviewed provided little guidance for managing telephone presentations. The Directors of Nursing perceived policy content and enactment to be largely inadequate. When organisational structures failed to provide appropriate governance for the context, the Directors of Nursing engaged in protective mechanisms to support rural nurses who manage telephone presentations. Rural Directors of Nursing employed intuitive behaviours to protect rural nurses practicing within a clinical governance context that is inadequate for the

Energy Efficiency Governance

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The purpose of this report is to help EE practitioners, government officials and stakeholders to establish the most effective EE governance structures, given their specific country context. It also aims to provide readers with relevant and accessible information to support the development of comprehensive and effective governance mechanisms. The International Energy Agency (IEA) conducted a global review of many elements of EE governance,including legal frameworks, institutional frameworks, funding mechanisms, co-ordination mechanisms and accountability arrangements, such as evaluation and oversight. The research tools included a survey of over 500 EE experts in 110 countries, follow-up interviews of over 120 experts in 27 countries and extensive desk study and literature searches on good EE governance.

Cognitive mechanisms for explaining dynamics of aesthetic appreciation

Science.gov (United States)

Carbon, Claus-Christian

2011-01-01

For many domains aesthetic appreciation has proven to be highly reliable. Evaluations of facial attractiveness, for instance, show high internal consistencies and impressively high inter-rater reliabilities, even across cultures. This indicates general mechanisms underlying such evaluations. It is, however, also obvious that our taste for specific objects is not always stable—in some realms such stability is hardly conceivable at all since aesthetic domains such as fashion, design, or art are inherently very dynamic. Gaining insights into the cognitive mechanisms that trigger and enable corresponding changes of aesthetic appreciation is of particular interest for psychologists as this will probably reveal essential mechanisms of aesthetic evaluations per se. The present paper develops a two-step model, dynamically adapting itself, which accounts for typical dynamics of aesthetic appreciation found in different research areas such as art history, philosophy, and psychology. The first step assumes singular creative sources creating and establishing innovative material towards which, in a second step, people adapt by integrating it into their visual habits. This inherently leads to dynamic changes of the beholders— aesthetic appreciation. PMID:23145254

Dynamic Analysis of Hammer Mechanism "Twin Hammer" of Impact Wrench

Science.gov (United States)

Konečný, M.; Slavík, J.

This paper describes function of the hammer mechanism "Twin hammer" the impact wrench, calculation of dynamic forces exerted on the mechanism and determining the contact pressures between the parts of the mechanism. The modelling of parts was performed in system Pro ENGINEER—standard. The simulation and finding dynamic forces was performed in advanced module Pro ENGINEER—mechanism design and finding contacts pressures in modul Pro ENGENEER—mechanica.

Governance Challenges in Telecoupled Food Systems

Science.gov (United States)

Eakin, H.; Mahanti, A.; Rueda, X.

2015-12-01

Distal connections increasingly influence food systems' governance: social actors in one geographic context produce intended and unintended consequences in distant locations, coupling the dynamics of socio-ecological systems. While these linkages are not new, economic globalization, urbanization and the dynamics of consumer preferences have accentuated these 'telecoupled' relationships in food systems. Telecoupling refers to the unexpected causal interactions among human-environment systems that were otherwise not linked. This paper presents a framework for evaluating telecoupling processes and outcomes in food systems, focusing on how the disparate scales of drivers and outcomes, diverse values of actors involved, and spatial and social distance combine to challenge socio-ecological system governance. We draw from two examples of food systems (coffee and maize) to argue that telecoupling, as a challenge for food systems, emerges when the institutions and mechanisms of governance acting over one system do not account for the consequences and interactions involving a different system. Telecoupling can stimulate new forms of governance, such as the development of codes of conduct and certification schemes, with positive impacts on food and livelihood security. Our cases suggest that the emergence of new governance arrangements is at least partially contingent on the prior existence of alternative social networks, which cultivate shared values, meanings and goals in food systems, as well as the capacity of affected actors to mobilize political influence and demonstrate plausible causal links. In the absence of such networks and associated capacities, the prior governance arrangements, although poorly adjusted to the new circumstances, are likely to persist, reinforcing existing power relations and the probability of undesirable social and ecological outcomes.

Environmental/dynamic mechanical equipment qualification and dynamic electrical equipment qualification program (EDQP)

International Nuclear Information System (INIS)

Hunter, J.A.

1984-01-01

Equipment qualification research is being conducted to investigate acceptable criteria, requirements, and methodologies for the dynamic (including seismic) and environmental qualification of mechanical equipment and for the dynamic (including seismic) qualification of electrical equipment. The program is organized into three elements: (1) General Research, (2) Environmental Research, and (3) Dynamic Research. This paper presents the highlights of the results to date in these three elements of the program

Dynamic mechanical properties of buffer material

International Nuclear Information System (INIS)

Takaji, Kazuhiko; Taniguchi, Wataru

1999-11-01

The buffer material is expected to maintain its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. over a long period of time. Natural clay is mentioned as a material that can relatively satisfy above. Among the kinds of natural clay, bentonite when compacted is superior because (i) it has exceptionally low water permeability and properties to control the movement of water in buffer, (ii) it fills void spaces in the buffer and fractures in the host rock as it swells upon water uptake, (iii) it has the ability to exchange cations and to adsorb cationic radioelements. In order to confirm these functions for the purpose of safety assessment, it is necessary to evaluate buffer properties through laboratory tests and engineering-scale tests, and to make assessments based on the ranges in the data obtained. This report describes the procedures, test conditions, results and examinations on the buffer material of dynamic triaxial tests, measurement of elastic wave velocity and liquefaction tests that aim at getting hold of dynamic mechanical properties. We can get hold of dependency on the shearing strain of the shearing modulus and hysteresis damping constant, the application for the mechanical model etc. by dynamic triaxial tests, the acceptability of maximum shearing modulus obtained from dynamic triaxial tests etc. by measurement of elastic wave velocity and dynamic strength caused by cyclic stress etc. by liquefaction tests. (author)

Corporate Governance at the Nacional Telecommunications Agency (ANATEL as a mechanism to improve the Agency’s Management

Directory of Open Access Journals (Sweden)

Fábio de Paula e Souza

2016-04-01

Full Text Available In the current scenario facing the country's government crisis of confidence, transparency and relationship with society, corporate governance is an important tool to monitor and improve the management, governance and corporate social responsibility in public organizations. The application of this mechanism in the National Telecommunications Agency (ANATEL has great impact to the economy and technological development of the country, capturing investments in the telecommunications sector, generating confidence to investors and stimulating competition between companies, which can offer products with best quality and services at affordable prices for consumers in Brazil. This paper investigates and analyzes by the theory of regulation, guides and reports, corporate governance as a mechanism to improve the management in ANATEL, using references, legislation and other documents in order to examine the transparency, fairness, accountability (providing accounts and corporate social responsibility in the Agency.

A comparative study on dynamic mechanical performance of concrete and rock

Directory of Open Access Journals (Sweden)

Xia Zhengbing

2015-10-01

Full Text Available of underground cavities and field-leveling excavation. Dynamic mechanical performance of rocks has been gradually attached importance both in China and abroad. Concrete and rock are two kinds of the most frequently used engineering materials and also frequently used as experimental objects currently. To compare dynamic mechanical performance of these two materials, this study performed dynamic compression test with five different strain rates on concrete and rock using Split Hopkinson Pressure Bar (SHPB to obtain basic dynamic mechanical parameters of them and then summarized the relationship of dynamic compressive strength, peak strain and strain rate of two materials. Moreover, specific energy absorption is introduced to confirm dynamic damage mechanisms of concrete and rock materials. This work can not only help to improve working efficiency to the largest extent but also ensure the smooth development of engineering, providing rich theoretical guidance for development of related engineering in the future

Governance mechanisms in transnational business relationships

OpenAIRE

Homburg, Christian; Kiedaisch, Ingo; Cannon, Joseph P.

1999-01-01

Empirical research on buyer-supplier relationships has almost exclusively examined domestic (both firms from the same country) exchange. The growing importance of international marketing and global sourcing suggest a need to understand relationships across national boundaries -- transnational business relationships. Drawing on theories of governance, the authors hypothesize differences in governance between domestic and transnational business relationships. They examine the use...

Dynamic Matching Markets and the Deferred Acceptance Mechanism

DEFF Research Database (Denmark)

Kennes, John; Monte, Daniel; Tumennasan, Norovsambuu

In many dynamic matching markets, priorities depend on previous allocations. In such environments, agents on the proposing side can manipulate the period-by-period deferred acceptance (DA) mechanism. We show that the fraction of agents with incentives to manipulate the DA mechanism approaches zero...... as the market size increases. In addition, we provide a novel al- gorithm to calculate the percentage of markets that can be manipulated. Based on randomly generated data, we find that the DA becomes approximately non-manipulable when the schools capacity reaches 20. Our theoretical and simulation results...... together justify the implementation of the period-by-period DA mechanism in dynamic markets....

Mechanisms of e-government activity in the Republic of Moldova compared to the decision-making framework of EU internationalization

Directory of Open Access Journals (Sweden)

Victoria GOREA

2016-06-01

Full Text Available The performances of the macrosystem e-Government denotes the macro and microenvironments of decision moving through the implementation and application of a variety of mechanisms and tools, which being diversified contribute to fortifying the common public opinion. The cyber administration develops the most important mechanisms to reinforce the uniformity of the microenvironment e-Government. The Republic of Moldova is a component and participative part of the evolutionary decisional microsystem of e-Government similar to the directives of the macrosystem vectors.

Gas Bubble Dynamics under Mechanical Vibrations

Science.gov (United States)

Mohagheghian, Shahrouz; Elbing, Brian

2017-11-01

The scientific community has a limited understanding of the bubble dynamics under mechanical oscillations due to over simplification of Navier-Stockes equation by neglecting the shear stress tensor and not accounting for body forces when calculating the acoustic radiation force. The current work experimental investigates bubble dynamics under mechanical vibration and resulting acoustic field by measuring the bubble size and velocity using high-speed imaging. The experimental setup consists of a custom-designed shaker table, cast acrylic bubble column, compressed air injection manifold and an optical imaging system. The mechanical vibrations resulted in accelerations between 0.25 to 10 times gravitational acceleration corresponding to frequency and amplitude range of 8 - 22Hz and 1 - 10mm respectively. Throughout testing the void fraction was limited to <5%. The bubble size is larger than resonance size and smaller than acoustic wavelength. The amplitude of acoustic pressure wave was estimated using the definition of Bjerknes force in combination with Rayleigh-Plesset equation. Physical behavior of the system was capture and classified. Bubble size, velocity as well as size and spatial distribution will be presented.

System dynamics for mechanical engineers

CERN Document Server

Davies, Matthew

2015-01-01

This textbook is ideal for mechanical engineering students preparing to enter the workforce during a time of rapidly accelerating technology, where they will be challenged to join interdisciplinary teams. It explains system dynamics using analogies familiar to the mechanical engineer while introducing new content in an intuitive fashion. The fundamentals provided in this book prepare the mechanical engineer to adapt to continuous technological advances with topics outside traditional mechanical engineering curricula by preparing them to apply basic principles and established approaches to new problems. This book also: ·         Reinforces the connection between the subject matter and engineering reality ·         Includes an instructor pack with the online publication that describes in-class experiments with minimal preparation requirements ·         Provides content dedicated to the modeling of modern interdisciplinary technological subjects, including opto-mechanical systems, high...

The Competing Dynamics and Relationships in Corporate and Local Government Agency Constructions of Place

Directory of Open Access Journals (Sweden)

Natalie Russell

2014-05-01

Full Text Available This paper explores the dynamics of how private sector business entities and local government bodies perceive and interact with the identity of the locality in which they operate. It identifies tensions and differences in, and consequences of, the dynamics and relationships between how private sector business entities view constructions of ‘place’ and how government and publicly-funded place-marketing organisations portray and promote localities. These issues are examined through the phenomenon, brand and slogan of ‘visit, live, invest’ which is gaining credence in the United Kingdom and elsewhere in the world. The paper develops data using in-depth interviews and a small-scale survey set within an overall interpretivistic case study approach. The data and the case-study demonstrate that, despite the rebranding of the local government agencies as a place-marketing organisation committed to the new ‘live, visit, invest’ initiative and brand agenda, there is an ongoing ‘cultural hangover’ from previous place promotion policies. There are also serious impacts and consequences for relationships between the public and private sectors and with other stakeholders. The prevailing image of UKTown (real name anonymised by business leaders is one that sees this town fundamentally as a historic, traditional and conservative town. This image has been the product of many years of older style promotion in this vein. While such an image may suggest pleasant aspects of the living environment, it has little to do with corporate image, values and concerns and many private sector business entities do not identity with it. In several instances it is even considered by certain business sectors to be ‘detrimental’ to the need for a dynamic business environment and the forms of relationships and activities these necessitate. The paper indicates a number of strategic moves that could be adopted in order to improve this predicament.

Hydrologic variability governs population dynamics of a vulnerable amphibian in an arid environment.

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Erin R Zylstra

Full Text Available Dynamics of many amphibian populations are governed by the distribution and availability of water. Therefore, understanding the hydrological mechanisms that explain spatial and temporal variation in occupancy and abundance will improve our ability to conserve and recover populations of vulnerable amphibians. We used 16 years of survey data from intermittent mountain streams in the Sonoran Desert to evaluate how availability of surface water affected survival and adult recruitment of a threatened amphibian, the lowland leopard frog (Lithobates yavapaiensis. Across the entire study period, monthly survival of adults ranged from 0.72 to 0.99 during summer and 0.59 to 0.94 during winter and increased with availability of surface water (Z = 7.66; P < 0.01. Recruitment of frogs into the adult age class occurred primarily during winter and ranged from 1.9 to 3.8 individuals/season/pool; like survival, recruitment increased with availability of surface water (Z = 3.67; P < 0.01. Although abundance of frogs varied across seasons and years, we found no evidence of a systematic trend during the 16-year study period. Given the strong influence of surface water on population dynamics of leopard frogs, conservation of many riparian obligates in this and similar arid regions likely depends critically on minimizing threats to structures and ecosystem processes that maintain surface waters. Understanding the influence of surface-water availability on riparian organisms is particularly important because climate change is likely to decrease precipitation and increase ambient temperatures in desert riparian systems, both of which have the potential to alter fundamentally the hydrology of these systems.

Coupling functions: Universal insights into dynamical interaction mechanisms

Science.gov (United States)

Stankovski, Tomislav; Pereira, Tiago; McClintock, Peter V. E.; Stefanovska, Aneta

2017-10-01

The dynamical systems found in nature are rarely isolated. Instead they interact and influence each other. The coupling functions that connect them contain detailed information about the functional mechanisms underlying the interactions and prescribe the physical rule specifying how an interaction occurs. A coherent and comprehensive review is presented encompassing the rapid progress made recently in the analysis, understanding, and applications of coupling functions. The basic concepts and characteristics of coupling functions are presented through demonstrative examples of different domains, revealing the mechanisms and emphasizing their multivariate nature. The theory of coupling functions is discussed through gradually increasing complexity from strong and weak interactions to globally coupled systems and networks. A variety of methods that have been developed for the detection and reconstruction of coupling functions from measured data is described. These methods are based on different statistical techniques for dynamical inference. Stemming from physics, such methods are being applied in diverse areas of science and technology, including chemistry, biology, physiology, neuroscience, social sciences, mechanics, and secure communications. This breadth of application illustrates the universality of coupling functions for studying the interaction mechanisms of coupled dynamical systems.

Mechanics and dynamics of triglyceride-phospholipid model membranes

DEFF Research Database (Denmark)

Pakkanen, Kirsi I.; Duelund, Lars; Qvortrup, Klaus

2011-01-01

We demonstrate here that triolein alters the mechanical properties of phospholipid membranes and induces extraordinary conformational dynamics. Triolein containing membranes exhibit fluctuations up to size range of 100µm and with the help of these are e.g. able to squeeze through narrow passages...... with larger lamellar distances observed in the TOPOPC membranes. These findings suggest repulsion between adjacent membranes. We provide a comprehensive discussion on the possible explanations for the observed mechanics and dynamics in the TOPOPC system and on their potential cellular implications....

Dynamic Support of Government in Online Shopping

OpenAIRE

Hai, Le Chi; Alam Kazmi, Syed Hasnain

2015-01-01

Advancements in online shopping for consumers requires consistent government support policies and the introduction of substantial government laws and regulations. In order to establish innovative developments in online shopping market environment that makes online shopping faster and stable, the government perspective is vital with the Technology Acceptance Model (TAM) for research and development in online shopping behavior for consumer’s confidence and their purchase intention. The proposed...

Mechanics of couple-stress fluid coatings

Science.gov (United States)

Waxman, A. M.

1982-01-01

The formal development of a theory of viscoelastic surface fluids with bending resistance - their kinematics, dynamics, and rheology are discussed. It is relevant to the mechanics of fluid drops and jets coated by a thin layer of immiscible fluid with rather general rheology. This approach unifies the hydrodynamics of two-dimensional fluids with the mechanics of an elastic shell in the spirit of a Cosserat continuum. There are three distinct facets to the formulation of surface continuum mechanics. Outlined are the important ideas and results associated with each: the kinematics of evolving surface geometries, the conservation laws governing the mechanics of surface continua, and the rheological equations of state governing the surface stress and moment tensors.

Investigating the Relationship between Governance Mechanisms and the Disclosure of IT Control Weaknesses

Science.gov (United States)

Hamdan, Basil

2012-01-01

The current research is concerned with exploring the quality of information technology (IT) control over financial reporting systems as reported under Section 404 of the Sarbanes-Oxley Act of 2002. More specifically, this dissertation examines the association between organizational governance mechanisms and the occurrence and subsequent disclosure…

Patching security governance : an empirical view of emergent governance mechanisms for cybersecurity

NARCIS (Netherlands)

van Eeten, M.J.G.

2017-01-01

Purpose: The issue of cybersecurity has been cast as the focal point of a fight between two conflicting governance models: the nation-state model of national security and the global governance model of multi-stakeholder collaboration, as seen in forums like IGF, IETF, ICANN, etc. There is a

Internal corporate governance mechanisms and audit report lag: A study of Malaysian listed companies

Directory of Open Access Journals (Sweden)

Ummi Junaidda Binti Hashim

2012-11-01

Full Text Available This study attempts to investigate the link between corporate governance mechanisms and audit report lag for companies listed on Bursa Malaysia from 2007 to 2009. The 288 companies listed on Bursa Malaysia have been randomly selected. The corporate governance mechanisms examined include the board of directors and audit committee. It shows that there are significant negative relationships between board diligence, audit committee independence and expertise. The higher the number of meetings being held indicates that the board is discharging their role towards the company. The results show that audit committee independence and audit committee expertise could assist in reducing audit report lag among companies in Malaysia. Its provide some evidence supporting the resource based theory, whereby characteristics of the audit committee, such as the resources and capabilities, could improve companies’ performance as well as corporate reporting.However, it could not provide any evidence concerning the link between board independence, board expertise, CEO duality and audit committee diligence on audit report lag. This study provides comprehensive examination of ARL on Malaysian listed companies for three years period. It is consider the initial study to provide a thorough examination of the association between corporate governance characteristics and ARL.

Relationship between Marketing Strategies and Governance Mechanisms: A Study in Exploration Chain Beef Cattle

Directory of Open Access Journals (Sweden)

Filipe Quevedo-Silva

2015-09-01

Full Text Available The relationship between actors has been unspoilt by marketing through the bias of Transaction Costs Economics. Some authors suggest that a marketing strategy can directly impact the transactional characteristics and hence the governance mechanisms chosen to coordinate transactions. Studies suggest that future work in the field of marketing include, among other factors, aspects related to the relationship between the actors. In this context, this article aims to analyze how marketing strategies can affect the choice of governance mechanisms. The study object is the chain of beef, view their representation to the national economy. To this end, we conducted a qualitative study using semi-structured interviews with various actors in the chain. It was possible to verify the existence of the relationship between marketing strategy and governance structure. In one of the cases, product differentiation, translated into more specific assets, led the producer to perform a relational contract with the fridge and to distribute your product, make an integration with retailers, through the opening of a boutique of meat. Factor that was not observed in transactions involving producers on products without distinction, for which the transactions via spot market are prevalent.  

Dynamic mechanical analysis of carbon nanotube-reinforced nanocomposites.

Science.gov (United States)

Her, Shiuh-Chuan; Lin, Kuan-Yu

2017-06-16

To predict the mechanical properties of multiwalled carbon nanotube (MWCNT)-reinforced polymers, it is necessary to understand the role of the nanotube-polymer interface with regard to load transfer and the formation of the interphase region. The main objective of this study was to explore and attempt to clarify the reinforcement mechanisms of MWCNTs in epoxy matrix. Nanocomposites were fabricated by adding different amounts of MWCNTs to epoxy resin. Tensile test and dynamic mechanical analysis (DMA) were conducted to investigate the effect of MWCNT contents on the mechanical properties and thermal stability of nanocomposites. Compared with the neat epoxy, nanocomposite reinforced with 1 wt% of MWCNTs exhibited an increase of 152% and 54% in Young's modulus and tensile strength, respectively. Dynamic mechanical analysis demonstrates that both the storage modulus and glass transition temperature tend to increase with the addition of MWCNTs. Scanning electron microscopy (SEM) observations reveal that uniform dispersion and strong interfacial adhesion between the MWCNTs and epoxy are achieved, resulting in the improvement of mechanical properties and thermal stability as compared with neat epoxy.

Investigation of the energy transport mechanism in the TCA tokamak by studying the plasma dynamical response

International Nuclear Information System (INIS)

Dudok de Wit, Th.; Duval, B.P.; Joye, B.; Lister, J.B.; Moret, J.M.

1989-01-01

The energy transport mechanisms that govern the electron temperature behaviour of a tokamak remain very badly understood and up to now no proper model has been proposed that can explain experimental observations such as profile consistency or the influence of the density profile. One approach to this problem, extensively used on TCA, is to study the dynamical response of the plasma due to externally imposed modifications of parameters which have an influence on the plasma energy content. The temporal evolution of the electron temperature will closely depend on the type and the characteristics of the implied mechanisms. Thus a detailed measurement of the dynamical response would reveal experimentally the dominant properties that would have to be taken into account in the elaboration of a model of the transport processes. Most of the results presented here were obtained by analysing the electron temperature response inferred from soft X-ray emissivity during modification of the plasma density due to either gas puffing, laser impurity ablation or alfven wave heating on TCA (a = 0.18 m, R = 0.61 m, B Φ = 1.52 T). 4 refs., 3 figs

The Generative Mechanisms of Open Government Data

DEFF Research Database (Denmark)

Jetzek, Thorhildur; Avital, Michel; Bjørn-Andersen, Niels

2013-01-01

The exponentially growing production of data enables global connectivity as well as increased openness and sharing, which turn into a powerful force that is changing the global economy and society. Governments around the world have become active participants in this evolution by opening up...... their data for access and re-use by public and private agents alike. The recent phenomenon of Open Government Data (OGD) has spread around the world, driven by the proposition that opening government data has the ability to generate both economic and social value. However, a review of the academic research...

Characterisation of Dynamic Mechanical Properties of Resistance Welding Machines

DEFF Research Database (Denmark)

Wu, Pei; Zhang, Wenqi; Bay, Niels

2005-01-01

characterizing the dynamic mechanical characteristics of resistance welding machines is suggested, and a test set-up is designed determining the basic, independent machine parameters required in the model. The model is verified by performing a series of mechanical tests as well as real projection welds.......The dynamic mechanical properties of a resistance welding machine have significant influence on weld quality, which must be considered when simulating the welding process numerically. However, due to the complexity of the machine structure and the mutual coupling of components of the machine system......, it is very difficult to measure or calculate the basic, independent machine parameters required in a mathematical model of the machine dynamics, and no test method has so far been presented in literature, which can be applied directly in an industrial environment. In this paper, a mathematical model...

Differential effects of plural ownership and governance mechanisms in limiting shirkers and free riders

OpenAIRE

Silkoset, Ragnhild; Nygaard, Arne; Kidwell, Roland E.

2016-01-01

Using evidence from paired franchisor-franchisee dyads, this study identifies how plural formed ownership mechanisms curb the risk of shirking and free riding in franchise systems. These risks have damaging effects on the invested capital of franchisee entrepreneurs. Although shirking and free riding produce a major source of uncertainty for the franchisee entrepreneur it can be limited by plural formed governance dimensions. These mechanisms have different effects based on unit status,...

Molecular dynamics and Monte Carlo calculations in statistical mechanics

International Nuclear Information System (INIS)

Wood, W.W.; Erpenbeck, J.J.

1976-01-01

Monte Carlo and molecular dynamics calculations on statistical mechanical systems is reviewed giving some of the more significant recent developments. It is noted that the term molecular dynamics refers to the time-averaging technique for hard-core and square-well interactions and for continuous force-law interactions. Ergodic questions, methodology, quantum mechanical, Lorentz, and one-dimensional, hard-core, and square and triangular-well systems, short-range soft potentials, and other systems are included. 268 references

Mechanical Cushion Design Influence on Cylinder Dynamics

DEFF Research Database (Denmark)

Borghi, Massimo; Milani, Massimo; Conrad, Finn

2005-01-01

. experimental comparison, involving the piston velocity and the cylinder chambers pressure. After, with the aim of highlighting the effect of mechanical cushions design on a two effect linear actuator dynamic performances, the characteristics modulation of four alternative cushioning systems are determined......The paper deals with the simulation and the experimental verification of the dynamic behaviour of a linear actuator equipped with different configurations of mechanical cushion. A numerical model, developed and tailored to describe the influence of different modulation of the discharged flow......-rate (and of the correspondent discharging orifice design) on the cushioning characteristics variation is firstly introduced. Then, with respect to the case of the cylindrical cushioning engagement, both the reliability and the limits of the numerical approach are highlighted through a numerical vs...

Dynamic processes of domain switching in lead zirconate titanate under cyclic mechanical loading by in situ neutron diffraction

International Nuclear Information System (INIS)

Pojprapai, Soodkhet; Luo, Zhenhua; Clausen, Bjorn; Vogel, Sven C.; Brown, Donald W.; Russel, Jennifer; Hoffman, Mark

2010-01-01

The performance of ferroelectric ceramics is governed by the ability of domains to switch. A decrease in the switching ability can lead to degradation of the materials and failure of ferroelectric devices. In this work the dynamic properties of domain reorientation are studied. In situ time-of-flight neutron diffraction is used to probe the evolution of ferroelastic domain texture under mechanical cyclic loading in bulk lead zirconate titanate ceramics. The high sensitivity of neutron diffraction to lattice strain is exploited to precisely analyze the change of domain texture and strain through a full-pattern Rietveld method. These results are then used to construct a viscoelastic model, which explains the correlation between macroscopic phenomena (i.e. creep and recovered deformation) and microscopic dynamic behavior (i.e. ferroelastic switching, lattice strain).

Public-private interactions in global food safety governance.

Science.gov (United States)

Lin, Ching-Fu

2014-01-01

In response to an apparent decline in global food safety, numerous public and private regulatory initiatives have emerged to restore public confidence. This trend has been particularly marked by the growing influence of private regulators such as multinational food companies, supermarket chains and non-governmental organizations (NGOs), who employ private standards, certification protocols, third-party auditing, and transnational contracting practices. This paper explores how the structure and processes of private food safety governance interact with traditional public governance regimes, focusing on Global Good Agricultural Practices (GlobalGAP) as a primary example of the former. Due to the inefficiency and ineffectiveness of public regulation in the face of global problems, private governance in food safety has gradually replaced states' command-and-control regulation with more flexible, market-oriented mechanisms. The paper concludes by emphasizing the importance of constructive regime interaction instead of institutional boundary building to global food safety governance. Public and private ordering must each play a role as integral parts of a larger, dynamic and evolving governance complex.

Governing Forest Landscape Restoration: Cases from Indonesia

Directory of Open Access Journals (Sweden)

Cora van Oosten

2014-05-01

Full Text Available Forest landscape restoration includes both the planning and implementation of measures to restore degraded forests within the perspective of the wider landscape. Governing forest landscape restoration requires fundamental considerations about the conceptualisation of forested landscapes and the types of restoration measures to be taken, and about who should be engaged in the governance process. A variety of governance approaches to forest landscape restoration exist, differing in both the nature of the object to be governed and the mode of governance. This paper analyses the nature and governance of restoration in three cases of forest landscape restoration in Indonesia. In each of these cases, both the original aim for restoration and the initiators of the process differ. The cases also differ in how deeply embedded they are in formal spatial planning mechanisms at the various political scales. Nonetheless, the cases show similar trends. All cases show a dynamic process of mobilising the landscape’s stakeholders, plus a flexible process of crafting institutional space for conflict management, negotiation and decision making at the landscape level. As a result, the landscape focus changed over time from reserved forests to forested mosaic lands. The cases illustrate that the governance of forest landscape restoration should not be based on strict design criteria, but rather on a flexible governance approach that stimulates the creation of novel public-private institutional arrangements at the landscape level.

The Conformational Dynamics of Cas9 Governing DNA Cleavage Are Revealed by Single-Molecule FRET.

Science.gov (United States)

Yang, Mengyi; Peng, Sijia; Sun, Ruirui; Lin, Jingdi; Wang, Nan; Chen, Chunlai

2018-01-09

Off-target binding and cleavage by Cas9 pose major challenges in its application. How the conformational dynamics of Cas9 govern its nuclease activity under on- and off-target conditions remains largely unknown. Here, using intra-molecular single-molecule fluorescence resonance energy transfer measurements, we revealed that Cas9 in apo, sgRNA-bound, and dsDNA/sgRNA-bound forms spontaneously transits among three major conformational states, mainly reflecting significant conformational mobility of the catalytic HNH domain. We also uncovered surprising long-range allosteric communication between the HNH domain and the RNA/DNA heteroduplex at the PAM-distal end to ensure correct positioning of the catalytic site, which demonstrated that a unique proofreading mechanism served as the last checkpoint before DNA cleavage. Several Cas9 residues were likely to mediate the allosteric communication and proofreading step. Modulating interactions between Cas9 and heteroduplex at the PAM-distal end by introducing mutations on these sites provides an alternative route to improve and optimize the CRISPR/Cas9 toolbox. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Dynamic mechanical properties of toughened polyamide composites

International Nuclear Information System (INIS)

Alsewailem, Fares D.

2008-01-01

The effect of incorporating thermoplastic rubber on the dynamic mechanical properties, storage and loss moduli, of virgin and recycled glass-fiber-reinforced polyamide 66 has been investigated in this study. Styrene-Ethylene-Styrene and Ethylene-Propylene grafted with maleic anhydride were used as elastomers for toughening. Dynamic mechanical properties of the composites were examined by the rotational rhometry. Shear storage and loss moduli of recycled and virgin materials were measured against frequency. Also the variation of storage modulus of the virgin composites was measured against temperatures by conducting a series of torsion tests. Both dynamic storage and loss moduli of the composites were found to increase with increasing glass fiber and rubber contents. Recycled composites had lower values of dynamic modulus compared that of virgin composites; however by proper combining of fiber and rubber into the recycled material, its modulus fairly matches that of the virgin material. Addition of rubber to virgin composites causes a reduction in G' as temperature increases. Rubber, which acts as a stress concentrator, had a major effect on minimizing the overall modulus of the composites. The in G' versus temperature has been observed for all composites: however the temperature at which the transition G' occurs decreases with increasing rubber content. (author)

Water Governance and Adaptation to Disturbances in Irrigated Semi-Arid Agricultural Systems

Science.gov (United States)

Evans, T. P.; McCord, P. F.; McBride, L.; Gower, D.; Caylor, K. K.

2013-12-01

Climate and other physical drivers of environmental systems are modifying the global availability of water for irrigation. At the same time population growth is placing an increased demand on water resources as local municipalities promote agricultural production as a mechanism to support human welfare and development. Substantial has research focused on household-level agricultural decision-making and adaptation. But equally important are institutional dynamics, or the rules implemented to allocate water resources across different user groups. Previous work has identified design principles for common-pool resource systems that tend to lead to sustained governance regimes. Likewise, past research has addressed the issue of "institutional fit", or locally adapted governance arrangements characterized through governance structure. However, much of the complexity behind institutional dynamics and adaptive capacity lies in the translation of data to information to knowledge, and how this sequence contributes to effective cross-scale water management and decision-making - an arena that has arguably received less attention in the water management literature. We investigate the interplay between governance regimes, data/information and institutional dynamics in irrigation systems in semi-arid regions of Kenya. In particular, we articulate the role of knowledge and data in institutional dynamics at multiple levels of analysis. How do users at different decision-making levels incorporate social and hydrological information in water governance? What data is needed to develop the information and knowledge users need for effective management? While governance structure is certainly a critical component of water management systems - we emphasize the interplay between the data-information-knowledge sequence and institutional dynamics. We present findings from household and manager-level surveys examining irrigation practices and the institutions designed to equitably allocate

Accelerating the transition towards sustainability dynamics into supply chain relationship management and governance structures

DEFF Research Database (Denmark)

Govindan, Kannan; Seuring, Stefan; Zhu, Qinghua

2016-01-01

successful futures by maintaining a healthy balance among economic, environmental, and social resources/dimensions. Consequently, some organizations have begun to integrate these dimensions in recent years. Researchers and practitioners are also working to accelerate the transition for more equitable......, sustainable, post-fossil carbon societies by working with all relevant stakeholders. This Special Volume of Journal of Cleaner Production is focused upon on diverse types of supply chain relationships, governance mechanisms, and innovations, which can foster effective and efficient sustainable supply chain...... management. This volume is comprised of twenty-seven articles and a book review. Fifteen of the articles address the supply chain relationships domain, while five focus primarily upon governance, five upon innovation, and two on relationships and governance. However, there is a huge potential to further...

Synchronization and chaotic dynamics of coupled mechanical metronomes

Science.gov (United States)

Ulrichs, Henning; Mann, Andreas; Parlitz, Ulrich

2009-12-01

Synchronization scenarios of coupled mechanical metronomes are studied by means of numerical simulations showing the onset of synchronization for two, three, and 100 globally coupled metronomes in terms of Arnol'd tongues in parameter space and a Kuramoto transition as a function of coupling strength. Furthermore, we study the dynamics of metronomes where overturning is possible. In this case hyperchaotic dynamics associated with some diffusion process in configuration space is observed, indicating the potential complexity of metronome dynamics.

A qrr noncoding RNA deploys four different regulatory mechanisms to optimize quorum-sensing dynamics.

Science.gov (United States)

Feng, Lihui; Rutherford, Steven T; Papenfort, Kai; Bagert, John D; van Kessel, Julia C; Tirrell, David A; Wingreen, Ned S; Bassler, Bonnie L

2015-01-15

Quorum sensing is a cell-cell communication process that bacteria use to transition between individual and social lifestyles. In vibrios, homologous small RNAs called the Qrr sRNAs function at the center of quorum-sensing pathways. The Qrr sRNAs regulate multiple mRNA targets including those encoding the quorum-sensing regulatory components luxR, luxO, luxM, and aphA. We show that a representative Qrr, Qrr3, uses four distinct mechanisms to control its particular targets: the Qrr3 sRNA represses luxR through catalytic degradation, represses luxM through coupled degradation, represses luxO through sequestration, and activates aphA by revealing the ribosome binding site while the sRNA itself is degraded. Qrr3 forms different base-pairing interactions with each mRNA target, and the particular pairing strategy determines which regulatory mechanism occurs. Combined mathematical modeling and experiments show that the specific Qrr regulatory mechanism employed governs the potency, dynamics, and competition of target mRNA regulation, which in turn, defines the overall quorum-sensing response. Copyright © 2015 Elsevier Inc. All rights reserved.

Nambu mechanics for stochastic magnetization dynamics

Energy Technology Data Exchange (ETDEWEB)

Thibaudeau, Pascal, E-mail: pascal.thibaudeau@cea.fr [CEA DAM/Le Ripault, BP 16, F-37260 Monts (France); Nussle, Thomas, E-mail: thomas.nussle@cea.fr [CEA DAM/Le Ripault, BP 16, F-37260 Monts (France); CNRS-Laboratoire de Mathématiques et Physique Théorique (UMR 7350), Fédération de Recherche “Denis Poisson” (FR2964), Département de Physique, Université de Tours, Parc de Grandmont, F-37200 Tours (France); Nicolis, Stam, E-mail: stam.nicolis@lmpt.univ-tours.fr [CNRS-Laboratoire de Mathématiques et Physique Théorique (UMR 7350), Fédération de Recherche “Denis Poisson” (FR2964), Département de Physique, Université de Tours, Parc de Grandmont, F-37200 Tours (France)

2017-06-15

Highlights: • The LLG equation can be formulated in the framework of dissipative Nambu mechanics. • A master equation is derived for the spin dynamics for additive/multiplicative noises. • The derived stochastic equations are compared to moment equations obtained by closures. - Abstract: The Landau–Lifshitz–Gilbert (LLG) equation describes the dynamics of a damped magnetization vector that can be understood as a generalization of Larmor spin precession. The LLG equation cannot be deduced from the Hamiltonian framework, by introducing a coupling to a usual bath, but requires the introduction of additional constraints. It is shown that these constraints can be formulated elegantly and consistently in the framework of dissipative Nambu mechanics. This has many consequences for both the variational principle and for topological aspects of hidden symmetries that control conserved quantities. We particularly study how the damping terms of dissipative Nambu mechanics affect the consistent interaction of magnetic systems with stochastic reservoirs and derive a master equation for the magnetization. The proposals are supported by numerical studies using symplectic integrators that preserve the topological structure of Nambu equations. These results are compared to computations performed by direct sampling of the stochastic equations and by using closure assumptions for the moment equations, deduced from the master equation.

Dynamic balancing of mechanisms and synthesizing of parallel robots

CERN Document Server

Wei, Bin

2016-01-01

This book covers the state-of-the-art technologies in dynamic balancing of mechanisms with minimum increase of mass and inertia. The synthesis of parallel robots based on the Decomposition and Integration concept is also covered in detail. The latest advances are described, including different balancing principles, design of reactionless mechanisms with minimum increase of mass and inertia, and synthesizing parallel robots. This is an ideal book for mechanical engineering students and researchers who are interested in the dynamic balancing of mechanisms and synthesizing of parallel robots. This book also: ·       Broadens reader understanding of the synthesis of parallel robots based on the Decomposition and Integration concept ·       Reinforces basic principles with detailed coverage of different balancing principles, including input torque balancing mechanisms ·       Reviews exhaustively the key recent research into the design of reactionless mechanisms with minimum increase of mass a...

Emerging Dynamic Design Techniques for Mechanical and ...

Indian Academy of Sciences (India)

Emerging Dynamic Design Techniques for Mechanical ... through this school to bring about an awareness of the state-of-art of the software and ... those mentioned above, cannot be ensured on the basis of approaches involving numerical.

Study on dynamic lifting characteristics of control rod drive mechanism

International Nuclear Information System (INIS)

Shen Xiaoyao

2012-01-01

Based on the equations of the electric circuit and the magnetic circuit and analysis of the dynamic lifting process for the control rod drive mechanism (CRDM), coupled magnetic-electric-mechanical equations both for the static status and the dynamic status are derived. The analytical method is utilized to obtain the current and the time when the lift starts. The numerical simulation method of dynamic analysis recommended by ASME Code is utilized to simulate the dynamic lifting process of CRDM, and the dynamic features of the system with different design gaps are studied. Conclusions are drawn as: (1) the lifting-start time increases with the design gap, and the time for the lifting process is longer with larger gaps; (2) the lifting velocity increases with time; (3) the lifting acceleration increases with time, and with smaller gaps, the impact acceleration is larger. (author)

Testing the effectiveness of network governance mechanisms to foster ambidexterity of agricultural innovation networks in East and Central Africa

NARCIS (Netherlands)

Pérez Perdomo, Silvia Andrea; Farrow, Andrew; Trienekens, Jacques H.; Omta, Onno S.W.F.; Velde, van der Gerben

2017-01-01

We tested three innovation network governance mechanisms for exploring and exploiting innovation opportunities. We analysed household-level panel data from agricultural innovation networks in Uganda, the Democratic Republic of the Congo and Rwanda. We found that first-order governed networks

Dynamic Mechanical Compression of Chondrocytes for Tissue Engineering: A Critical Review

Directory of Open Access Journals (Sweden)

Devon E. Anderson

2017-12-01

Full Text Available Articular cartilage functions to transmit and translate loads. In a classical structure–function relationship, the tissue resides in a dynamic mechanical environment that drives the formation of a highly organized tissue architecture suited to its biomechanical role. The dynamic mechanical environment includes multiaxial compressive and shear strains as well as hydrostatic and osmotic pressures. As the mechanical environment is known to modulate cell fate and influence tissue development toward a defined architecture in situ, dynamic mechanical loading has been hypothesized to induce the structure–function relationship during attempts at in vitro regeneration of articular cartilage. Researchers have designed increasingly sophisticated bioreactors with dynamic mechanical regimes, but the response of chondrocytes to dynamic compression and shear loading remains poorly characterized due to wide variation in study design, system variables, and outcome measurements. We assessed the literature pertaining to the use of dynamic compressive bioreactors for in vitro generation of cartilaginous tissue from primary and expanded chondrocytes. We used specific search terms to identify relevant publications from the PubMed database and manually sorted the data. It was very challenging to find consensus between studies because of species, age, cell source, and culture differences, coupled with the many loading regimes and the types of analyses used. Early studies that evaluated the response of primary bovine chondrocytes within hydrogels, and that employed dynamic single-axis compression with physiologic loading parameters, reported consistently favorable responses at the tissue level, with upregulation of biochemical synthesis and biomechanical properties. However, they rarely assessed the cellular response with gene expression or mechanotransduction pathway analyses. Later studies that employed increasingly sophisticated biomaterial-based systems, cells

Dynamic Mechanical Compression of Chondrocytes for Tissue Engineering: A Critical Review.

Science.gov (United States)

Anderson, Devon E; Johnstone, Brian

2017-01-01

Articular cartilage functions to transmit and translate loads. In a classical structure-function relationship, the tissue resides in a dynamic mechanical environment that drives the formation of a highly organized tissue architecture suited to its biomechanical role. The dynamic mechanical environment includes multiaxial compressive and shear strains as well as hydrostatic and osmotic pressures. As the mechanical environment is known to modulate cell fate and influence tissue development toward a defined architecture in situ , dynamic mechanical loading has been hypothesized to induce the structure-function relationship during attempts at in vitro regeneration of articular cartilage. Researchers have designed increasingly sophisticated bioreactors with dynamic mechanical regimes, but the response of chondrocytes to dynamic compression and shear loading remains poorly characterized due to wide variation in study design, system variables, and outcome measurements. We assessed the literature pertaining to the use of dynamic compressive bioreactors for in vitro generation of cartilaginous tissue from primary and expanded chondrocytes. We used specific search terms to identify relevant publications from the PubMed database and manually sorted the data. It was very challenging to find consensus between studies because of species, age, cell source, and culture differences, coupled with the many loading regimes and the types of analyses used. Early studies that evaluated the response of primary bovine chondrocytes within hydrogels, and that employed dynamic single-axis compression with physiologic loading parameters, reported consistently favorable responses at the tissue level, with upregulation of biochemical synthesis and biomechanical properties. However, they rarely assessed the cellular response with gene expression or mechanotransduction pathway analyses. Later studies that employed increasingly sophisticated biomaterial-based systems, cells derived from different

Features wear nodes mechanization wing aircraft operating under dynamic loads

Directory of Open Access Journals (Sweden)

А.М. Хімко

2009-03-01

Full Text Available  The conducted researches of titanic alloy ВТ-22 at dynamic loading with cycled sliding and dynamic loading in conditions of rolling with slipping. It is established that roller jamming in the carriage increases wear of rod of mechanization of a wing to twenty times. The optimum covering for strengthening wearied sites and restoration of working surfaces of wing’s mechanization rod is defined.

Real-time electricity pricing mechanism in China based on system dynamics

International Nuclear Information System (INIS)

He, Yongxiu; Zhang, Jixiang

2015-01-01

Highlights: • The system dynamics is used to research the real-time electricity pricing mechanism. • Four kinds of the real-time electricity pricing models are carried out and simulated. • It analysed the electricity price, the user satisfaction and the social benefits under the different models. • Market pricing is the trend of the real-time electricity pricing mechanism. • Initial development path of the real-time price mechanism for China is designed between 2015 and 2030. - Abstract: As an important means of demand-side response, the reasonable formulation of the electricity price mechanism will have an important impact on the balance between the supply and demand of electric power. With the introduction of Chinese intelligence apparatus and the rapid development of smart grids, real-time electricity pricing, as the frontier electricity pricing mechanism in the smart grid, will have great significance on the promotion of energy conservation and the improvement of the total social surplus. From the perspective of system dynamics, this paper studies different real-time electricity pricing mechanisms based on load structure, cost structure and bidding and analyses the situation of user satisfaction and the total social surplus under different pricing mechanisms. Finally, through the comparative analysis of examples under different real-time pricing scenarios, this paper aims to explore and design the future dynamic real-time electricity pricing mechanism in China, predicts the dynamic real-time pricing level and provides a reference for real-time electricity price promotion in the future

Soft tissue deformation modelling through neural dynamics-based reaction-diffusion mechanics.

Science.gov (United States)

Zhang, Jinao; Zhong, Yongmin; Gu, Chengfan

2018-05-30

Soft tissue deformation modelling forms the basis of development of surgical simulation, surgical planning and robotic-assisted minimally invasive surgery. This paper presents a new methodology for modelling of soft tissue deformation based on reaction-diffusion mechanics via neural dynamics. The potential energy stored in soft tissues due to a mechanical load to deform tissues away from their rest state is treated as the equivalent transmembrane potential energy, and it is distributed in the tissue masses in the manner of reaction-diffusion propagation of nonlinear electrical waves. The reaction-diffusion propagation of mechanical potential energy and nonrigid mechanics of motion are combined to model soft tissue deformation and its dynamics, both of which are further formulated as the dynamics of cellular neural networks to achieve real-time computational performance. The proposed methodology is implemented with a haptic device for interactive soft tissue deformation with force feedback. Experimental results demonstrate that the proposed methodology exhibits nonlinear force-displacement relationship for nonlinear soft tissue deformation. Homogeneous, anisotropic and heterogeneous soft tissue material properties can be modelled through the inherent physical properties of mass points. Graphical abstract Soft tissue deformation modelling with haptic feedback via neural dynamics-based reaction-diffusion mechanics.

The 2017 Nonlinear Mechanics and Dynamics Research Institute.

Energy Technology Data Exchange (ETDEWEB)

Kuether, Robert J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allensworth, Brooke Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Peebles, Diane E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-02-01

The 2017 Nonlinear Mechanics and Dynamics (NOMAD) Research Institute was successfully held from June 19 to July 28, 2017. NOMAD seeks to bring together participants with diverse tec hnical backgrounds to work in small teams to utilize an interactive approach to cultivate new ideas and approaches in engineering . NOMAD provides an opportunity for researchers - especially early career researchers - to develop lasting collaborations that go beyond what can be established from the limited interactions at their institutions or at annual conferences. A total of 17 students from around the world came to Albuquerque, New Mexico to participate in the six - week long program held at the University of New Mexico campus. The students collaborated on one of six research projects that were developed by various mentors from Sandia National Laboratories, academia, and other government laboratories. In addition to the research activities, the students atte nded weekly technical seminars, toured the National Museum of Nuclear Science & History, and socialized at various off - hour events including an Albuquerque Isotopes baseball game. At the end of the summer, the students gave a final technical presentation o n their research findings that was broadcast via Skype. Many of the research discoveries made at NOMAD are published as proceedings at t echnical conference s and have direct alignment with the critical mission work performed at Sandia.

Integrating adaptive governance and participatory multicriteria methods: a framework for climate adaptation governance

NARCIS (Netherlands)

Munaretto, S.; Siciliano, G.; Turvani, M.

2014-01-01

Climate adaptation is a dynamic social and institutional process where the governance dimension is receiving growing attention. Adaptive governance is an approach that promises to reduce uncertainty by improving the knowledge base for decision making. As uncertainty is an inherent feature of climate

THE EFFECT OF CORPORATE GOVERNANCE MECHANISM, OWNERSHIP STRUCTURE, AND EXTERNAL AUDITOR TOWARD CORPORATE SOCIAL RESPONSIBILITY DISCLOSURE WITH EARNING MANAGEMENT AS MODERATING VARIABLE

Directory of Open Access Journals (Sweden)

Suwana M.A.J.

2017-08-01

Full Text Available The purpose of this study is to examine the moderating effect of earning management on corporate governance mechanism, ownership structure, and external auditor toward corporate social responsibility disclosure. This study finds that the increase of ownership structure (foreign ownership and institutional ownership will increase corporate social responsibility disclosure. However corporate governance mechanism and external auditor is not affecting corporate social responsibility disclosure. Furthermore, this study provides additional empirical evidence for agency theory especially agency cost, that corporate governance mechanism, ownership structure, and Big Four audit firm do not have an effective role as agency cost to prevent or decrease earning management practice.

Hydration Control of the Mechanical and Dynamical Properties of Cellulose

Energy Technology Data Exchange (ETDEWEB)

Petridis, Loukas; O’Neill, Hugh M.; Johnsen, Mariah [Ripon College, Ripon, Wisconsin 54971, United States; Fan, Bingxin [Department; Schulz, Roland [Department; Mamontov, Eugene; Maranas, Janna [Department; Langan, Paul [Department; Smith, Jeremy C. [Department

2014-10-13

The mechanical and dynamical properties of cellulose, the most abundant biomolecule on earth, are essential for its function in plant cell walls and advanced biomaterials. Cellulose is almost always found in a hydrated state, and it is therefore important to understand how hydration influences its dynamics and mechanics. Here, the nanosecond-time scale dynamics of cellulose is characterized using dynamic neutron scattering experiments and molecular dynamics (MD) simulation. The experiments reveal that hydrated samples exhibit a higher average mean-square displacement above ~240 K. The MD simulation reveals that the fluctuations of the surface hydroxymethyl atoms determine the experimental temperature and hydration dependence. The increase in the conformational disorder of the surface hydroxymethyl groups with temperature follows the cellulose persistence length, suggesting a coupling between structural and mechanical properties of the biopolymer. In the MD simulation, 20% hydrated cellulose is more rigid than the dry form, due to more closely packed cellulose chains and water molecules bridging cellulose monomers with hydrogen bonds. This finding may have implications for understanding the origin of strength and rigidity of secondary plant cell walls. The detailed characterization obtained here describes how hydration-dependent increased fluctuations and hydroxymethyl disorder at the cellulose surface lead to enhancement of the rigidity of this important biomolecule.

Making partner relationship management systems work: The role of partnership governance mechanisms

OpenAIRE

Storey, C.; Kocabasoglu-Hillmer, C.

2013-01-01

While the adoption of Partner Relationship Management (PRM) systems by suppliers to manage and monitor its network of partners (i.e. resellers) has been on the rise, the performance improvements have not been consistently realized. Governance theory suggests this may be due to how the PRM system builds on the mechanisms employed by the supplier to oversee their partners. This study investigates how the two capabilities of PRM systems (relationship and fulfillment capabilities) and two partner...

Dynamic compressive mechanical response of a soft polymer material

NARCIS (Netherlands)

Fan, J.T.; Weerheijm, J.; Sluys, L.J.

2015-01-01

The dynamic mechanical behaviour of a soft polymer material (Clear Flex 75) was studied using a split Hopkinson pressure bar (SHPB) apparatus. Mechanical properties have been determined at moderate to high strain rates. Real time deformation and fracture were recorded using a high-speed camera.

Classical mechanics systems of particles and Hamiltonian dynamics

CERN Document Server

Greiner, Walter

2010-01-01

This textbook Classical Mechanics provides a complete survey on all aspects of classical mechanics in theoretical physics. An enormous number of worked examples and problems show students how to apply the abstract principles to realistic problems. The textbook covers Newtonian mechanics in rotating coordinate systems, mechanics of systems of point particles, vibrating systems and mechanics of rigid bodies. It thoroughly introduces and explains the Lagrange and Hamilton equations and the Hamilton-Jacobi theory. A large section on nonlinear dynamics and chaotic behavior of systems takes Classical Mechanics to newest development in physics. The new edition is completely revised and updated. New exercises and new sections in canonical transformation and Hamiltonian theory have been added.

Transformative environmental governance

Science.gov (United States)

Chaffin, Brian C.; Garmestani, Ahjond S.; Gunderson, Lance H.; Harm Benson, Melinda; Angeler, David G.; Arnold, Craig Anthony (Tony); Cosens, Barbara; Kundis Craig, Robin; Ruhl, J.B.; Allen, Craig R.

2016-01-01

Transformative governance is an approach to environmental governance that has the capacity to respond to, manage, and trigger regime shifts in coupled social-ecological systems (SESs) at multiple scales. The goal of transformative governance is to actively shift degraded SESs to alternative, more desirable, or more functional regimes by altering the structures and processes that define the system. Transformative governance is rooted in ecological theories to explain cross-scale dynamics in complex systems, as well as social theories of change, innovation, and technological transformation. Similar to adaptive governance, transformative governance involves a broad set of governance components, but requires additional capacity to foster new social-ecological regimes including increased risk tolerance, significant systemic investment, and restructured economies and power relations. Transformative governance has the potential to actively respond to regime shifts triggered by climate change, and thus future research should focus on identifying system drivers and leading indicators associated with social-ecological thresholds.

Dynamic response analysis as a tool for investigating transport mechanisms

International Nuclear Information System (INIS)

Dudok de Wit, Th.; Joye, B.; Lister, J.B.; Moret, J.M.

1990-01-01

Dynamic response analysis provides an attractive method for studying transport mechanisms in tokamak plasmas. The analysis of the radial response has already been widely used for heat and particle transport studies. The frequency dependence of the dynamic response, which is often omitted, reveals further properties of the dominant transport mechanisms. Extended measurements of the soft X-ray emission were carried out on the TCA tokamak in order to determine the underlying transport processes. (author) 5 refs., 2 figs

Dynamic Search and Working Memory in Social Recall

Science.gov (United States)

Hills, Thomas T.; Pachur, Thorsten

2012-01-01

What are the mechanisms underlying search in social memory (e.g., remembering the people one knows)? Do the search mechanisms involve dynamic local-to-global transitions similar to semantic search, and are these transitions governed by the general control of attention, associated with working memory span? To find out, we asked participants to…

Pitfall in quantum mechanical/molecular mechanical molecular dynamics simulation of small solutes in solution.

Science.gov (United States)

Hu, Hao; Liu, Haiyan

2013-05-30

Developments in computing hardware and algorithms have made direct molecular dynamics simulation with the combined quantum mechanical/molecular mechanical methods affordable for small solute molecules in solution, in which much improved accuracy can be obtained via the quantum mechanical treatment of the solute molecule and even sometimes water molecules in the first solvation shell. However, unlike the conventional molecular mechanical simulations of large molecules, e.g., proteins, in solutions, special care must be taken in the technical details of the simulation, including the thermostat of the solute/solvent system, so that the conformational space of the solute molecules can be properly sampled. We show here that the common setup for classical molecular mechanical molecular dynamics simulations, such as the Berendsen or single Nose-Hoover thermostat, and/or rigid water models could lead to pathological sampling of the solutes' conformation. In the extreme example of a methanol molecule in aqueous solution, improper and sluggish setups could generate two peaks in the distribution of the O-H bond length. We discuss the factors responsible for this somewhat unexpected result and evoke a simple and ancient technical fix-up to resolve this problem.

Design and Dynamic Modeling of Flexible Rehabilitation Mechanical Glove

Science.gov (United States)

Lin, M. X.; Ma, G. Y.; Liu, F. Q.; Sun, Q. S.; Song, A. Q.

2018-03-01

Rehabilitation gloves are equipment that helps rehabilitation doctors perform finger rehabilitation training, which can greatly reduce the labour intensity of rehabilitation doctors and make more people receive finger rehabilitation training. In the light of the defects of the existing rehabilitation gloves such as complicated structure and stiff movement, a rehabilitation mechanical glove is designed, which provides driving force by using the air cylinder and adopts a rope-spring mechanism to ensure the flexibility of the movement. In order to fit the size of different hands, the bandage ring which can adjust size is used to make the mechanism fixed. In the interest of solve the complex problem of dynamic equation, dynamic simulation is carried out by using Adams to obtain the motion curve, which is easy to optimize the structure of ring position.

A screw-based dynamic balancing approach, applied to a 5-bar mechanism

NARCIS (Netherlands)

de Jong, Jan Johannes; van Dijk, Johannes; Herder, Justus Laurens; Lenarcic, Jadran; Merlet, Jean-Pierre

2016-01-01

Dynamic balancing aims to reduce or eliminate the shaking base reaction forces and moments of mechanisms, in order to minimize vibration and wear. The derivation of the dynamic balance conditions requires significant algebraic effort, even for simple mechanisms. In this study, a screw-based

Mathematica for Theoretical Physics Classical Mechanics and Nonlinear Dynamics

CERN Document Server

Baumann, Gerd

2005-01-01

Mathematica for Theoretical Physics: Classical Mechanics and Nonlinear Dynamics This second edition of Baumann's Mathematica® in Theoretical Physics shows readers how to solve physical problems and deal with their underlying theoretical concepts while using Mathematica® to derive numeric and symbolic solutions. Each example and calculation can be evaluated by the reader, and the reader can change the example calculations and adopt the given code to related or similar problems. The second edition has been completely revised and expanded into two volumes: The first volume covers classical mechanics and nonlinear dynamics. Both topics are the basis of a regular mechanics course. The second volume covers electrodynamics, quantum mechanics, relativity, and fractals and fractional calculus. New examples have been added and the representation has been reworked to provide a more interactive problem-solving presentation. This book can be used as a textbook or as a reference work, by students and researchers alike. A...

Dynamic balancing of planar mechanisms using toric geometry

OpenAIRE

Moore, Brian; Schicho, Josef; Gosselin, Clement M.

2007-01-01

In this paper, a new method to determine the complete set of dynamically balanced planar four-bar mechanims is presented. Using complex variables to model the kinematics of the mechanism, the dynamic balancing constraints are written as algebraic equations over complex variables and joint angular velocities. After elimination of the joint angular velocity variables, the problem is formulated as a problem of factorization of Laurent polynomials. Using toric polynomial division, necessary and s...

Vibrational mechanics nonlinear dynamic effects, general approach, applications

CERN Document Server

Blekhman, Iliya I

2000-01-01

This important book deals with vibrational mechanics - the new, intensively developing section of nonlinear dynamics and the theory of nonlinear oscillations. It offers a general approach to the study of the effect of vibration on nonlinear mechanical systems.The book presents the mathematical apparatus of vibrational mechanics which is used to describe such nonlinear effects as the disappearance and appearance under vibration of stable positions of equilibrium and motions (i.e. attractors), the change of the rheological properties of the media, self-synchronization, self-balancing, the vibrat

Nonsmooth mechanics models, dynamics and control

CERN Document Server

Brogliato, Bernard

2016-01-01

Now in its third edition, this standard reference is a comprehensive treatment of nonsmooth mechanical systems refocused to give more prominence to control and modelling. It covers Lagrangian and Newton–Euler systems, detailing mathematical tools such as convex analysis and complementarity theory. The ways in which nonsmooth mechanics influence and are influenced by well-posedness analysis, numerical analysis and simulation, modelling and control are explained. Contact/impact laws, stability theory and trajectory-tracking control are given in-depth exposition connected by a framework formed from complementarity systems and measure-differential inclusions. Links are established with electrical circuits with set-valued nonsmooth elements and with other nonsmooth dynamical systems like impulsive and piecewise linear systems. Nonsmooth Mechanics (third edition) has been substantially rewritten, edited and updated to account for the significant body of results that have emerged in the twenty-first century—incl...

Effect of corporate governance mechanisms on the relationship between legal origins and cost of debt

DEFF Research Database (Denmark)

Farooq, Omar; Derrabi, Mohamed

2012-01-01

How do differences in country-level governance and enforcement mechanisms affect firms? Using a large dataset from the MENA region, we document that differences in legal traditions translate into differences in cost of debt. Our results show that firms headquartered in the common law countries ha...

Energy methods in dynamics

CERN Document Server

Le, Khanh Chau

2012-01-01

The above examples should make clear the necessity of understanding the mechanism of vibrations and waves in order to control them in an optimal way. However vibrations and waves are governed by differential equations which require, as a rule, rather complicated mathematical methods for their analysis. The aim of this textbook is to help students acquire both a good grasp of the first principles from which the governing equations can be derived, and the adequate mathematical methods for their solving. Its distinctive features, as seen from the title, lie in the systematic and intensive use of Hamilton's variational principle and its generalizations for deriving the governing equations of conservative and dissipative mechanical systems, and also in providing the direct variational-asymptotic analysis, whenever available, of the energy and dissipation for the solution of these equations. It will be demonstrated that many well-known methods in dynamics like those of Lindstedt-Poincare, Bogoliubov-Mitropolsky, Ko...

Mechanisms of shock-induced dynamic friction

International Nuclear Information System (INIS)

Winter, R E; Ball, G J; Keightley, P T

2006-01-01

The mechanism of shock-induced dynamic friction has been explored through an integrated programme of experiments and numerical simulations. A novel experimental technique has been developed for observing the sub-surface deformation in aluminium when sliding against a steel anvil at high velocity and pressure. The experimental observations suggest that slight differences in conditions at the interface between the metals affect frictional behaviour even at the very high-velocity, high-pressure regime studied here. However, a clear finding from the experimental work is the presence of two distinct modes of deformation termed deep and shallow. The deep deformation is observed in a region of the aluminium specimen where the interfacial velocity is relatively low and the shallow deformation is observed in a region where the interfacial velocity is higher. A 1D numerical treatment is presented which predicts the existence of two mechanisms for dynamic friction termed 'asymptotic melting' and 'slide-then-lock'. In both modes there is a warm-up phase in which the interface temperature is increased by frictional heating. For high initial sliding velocity, this is followed by the onset of the asymptotic melting state, in which the temperature is almost constant and melting is approached asymptotically. This mechanism produces low late-time frictional stress and shallow deformation. For lower initial sliding velocity, the warm-up terminates in a violent work hardening event that locks the interface and launches a strong plastic shear wave into the weaker material. This slide-then-lock mechanism is characterized by sustained high frictional stress and deep plastic deformation. These predicted mechanisms offer a plausible and consistent explanation for the abrupt transitions in the depth of sub-surface deformation observed in the experiments. A key conclusion arising from the current work is that the frictional stress does not vary smoothly with pressure or sliding velocity

Interlocking Friction Governs the Mechanical Fracture of Bilayer MoS2.

Science.gov (United States)

Jung, Gang Seob; Wang, Shanshan; Qin, Zhao; Martin-Martinez, Francisco J; Warner, Jamie H; Buehler, Markus J

2018-04-24

A molybdenum disulfide (MoS 2 ) layered system is a two-dimensional (2D) material, which is expected to provide the next generation of electronic devices together with graphene and other 2D materials. Due to its significance for future electronics applications, gaining a deep insight into the fundamental mechanisms upon MoS 2 fracture is crucial to prevent mechanical failure toward reliable applications. Here, we report direct experimental observation and atomic modeling of the complex failure behaviors of bilayer MoS 2 originating from highly variable interlayer frictions, elucidated with in situ transmission electron microscopy and large-scale reactive molecular dynamics simulations. Our results provide a systematic understanding of the effects that different stacking and loading conditions have on the failure mechanisms and crack-tip behaviors in the bilayer MoS 2 systems. Our findings unveil essential properties in fracture of this 2D material and provide mechanistic insight into its mechanical failure.

The use of meta-governance mechanisms to fight social segregation in Copenhagen

DEFF Research Database (Denmark)

Engberg, Lars A.

In 2011 Copenhagen City Council adopted a citywide Policy for Disadvantaged Areas in Copenhagen to combat geographically specific vicious circles of social deprivation and physical deterioration in the city. The policy was a result of an inter-departmental learning process, designed to come up wi...... study five years after adaptation of PDAC. The paper investigates how practices of joint leadership and meta-governance across city departments and between city officials and local stakeholders have been institutionalized as coordination mechanisms as a result of the new policy....

Dynamic Mechanical Properties of PMN/CNFs/EP Composites

International Nuclear Information System (INIS)

Shi Minxian; Huang Zhixiong; Qin Yan

2011-01-01

In this research, piezoelectric ceramic PMN(lead magnesium niobate-lead zirconate-lead titanate)/carbon nano-fibers(CNFs)/epoxy resin(EP) ccomposites were prepared and the dynamic mechanical properties and damping mechanism of PMN/CNFs/EP composites were investigated. The addition of CNFs into PMN/EP composite results in decrease of volume resistivity of the composite. When the concentration of CNFs is 0.6% weight of epoxy resin the volume resistivity of PMN/CNFs/EP composite is about 10 8 Ω·m. Dynamic mechanical analysis indicates that the loss factor, loss area, and damping temperature range of PMN/CNFs/EP composites increase with the CNFs content increasing till to 0.6% of weight of epoxy resin. When the CNFs content is more than 0.6% the damping properties of composites decrease oppositely. In PMN/CNFs/EP composites, the CNFs content 0.6% and the volume resistivity of PMN/CNFs/EP composites about 10 8 Ω·m just satisfy the practicing condition of piezo-damping, so the composites show optimal damping property.

Dynamical mechanism of symmetry breaking and particle mass generation in gauge field theories

International Nuclear Information System (INIS)

Miranskij, V.A.; Fomin, P.I.

1985-01-01

The dynamics of the spotaneous symmetry breaking and the particle mass generation in gauge theories with no fundamental scalar fields is considered. The emphasis is on the consideration of the symmetry breaking mechanism connected with the dynamics of the supercritical Coulomb-like forces caused by the gauge boson exchange between fermions. This mechanism is applied to different gauge theories, in particular, to the description of the spontaneous chira symmetry breaking in quantum chromodynamics. The mass relations for pseudoscalar meson nonet are obtained and it is shown that this mechanism resuls in the dynamical realisation of the hypothesis of the partial conservation of the axial-vector currents. The qualitative description of scalar mesons is given. The nature of the ultraviolet divergencies in quantum electrodynamics (QED) is investigated from the viewpoint of the dynamics of the fermion mass generation. The mechanism of the appearance of the additional (in comparison with perturbation theory) ultraviolet divergencies in QED with large bare coupling constant is indicated. The physical phenomenon underlying this mechanism is identified as the field theory analogue of the quantum mechanical ''fall into the centre'' (collapse) phenomenon. The similr phenomenon is shown to take place in some two-dimensional quantum field models. The dynamics of the bifermion condensates formation in tumblin gauge theories is briefly discussed

Epigenetic dynamics across the cell cycle

DEFF Research Database (Denmark)

Kheir, Tony Bou; Lund, Anders H.

2010-01-01

Progression of the mammalian cell cycle depends on correct timing and co-ordination of a series of events, which are managed by the cellular transcriptional machinery and epigenetic mechanisms governing genome accessibility. Epigenetic chromatin modifications are dynamic across the cell cycle...... a correct inheritance of epigenetic chromatin modifications to daughter cells. In this chapter, we summarize the current knowledge on the dynamics of epigenetic chromatin modifications during progression of the cell cycle....

Wigner's dynamical transition state theory in phase space : classical and quantum

NARCIS (Netherlands)

Waalkens, Holger; Schubert, Roman; Wiggins, Stephen

We develop Wigner's approach to a dynamical transition state theory in phase space in both the classical and quantum mechanical settings. The key to our development is the construction of a normal form for describing the dynamics in the neighbourhood of a specific type of saddle point that governs

DECREASING OF MECHANISMS DYNAMIC LOADING AT THE TRANSIENT STATE

Directory of Open Access Journals (Sweden)

V. S. Loveikin

2015-11-01

Full Text Available Purpose. It is necessary to select modes of motion to reduce the dynamic loads in the mechanisms. This choice should be made on optimization basis. The purpose of research is to study methods of synthesis regimes of mechanisms and machines motion that provide optimal modes of movement for terminal and integral criteria. Methodology. For research the one-mass dynamic model of the mechanism has been used. As optimization criteria the terminal and comprehensive integral criteria were used. The stated optimization problem has been solved using dynamic programming and variational calculation. The direct variation method, which allowed finding only approximate solution of the original problem of optimal control, has been used as well. Findings. The ways of ensuring the absolute minimum of terminal criterion have been set for each method of problem solving. The stated characteristics show softness changes of kinematic functions during braking of mechanism. They point to the absolute minimum of adopted terminal criterion in the calculation. Originality. It is necessary to introduce new variables in the system equations during the solving of optimal control problems using dynamic programming to achieve an absolute minimum of terminal criteria. In general, to achieve a minimum of n-order terminal criterion an optimization problem should find relatively (n+1-th order function. When optimization problems is solving by variational calculation in order to ensure a minimization of n-th order terminal criterion by selecting the appropriate boundary conditions, it is necessary to solve the Euler-Poisson 2(n+1-th order equation (subject to symmetric setting boundary conditions. It is a necessary condition for an extremum of the functional with the (n+1-th order integrant. Practical value. Minimizing of adopted terminal criterion in the calculation allows eliminate the brunt in kinematic gearing of mechanisms, which increases their operational life. In addition

Cross-Scale and Cross-Level Dynamics: Governance and Capacity for Resilience in a Social-Ecological System in Taiwan

Directory of Open Access Journals (Sweden)

Hsing-Sheng Tai

2015-02-01

Full Text Available Resilience thinking has strongly influenced how people understand and pursue sustainability of linked social-ecological systems. Resilience thinking highlights the need to build capacity and manage general system properties in a complex, constantly changing world. I modified an analytical framework to address associations among cross-scale and cross-level dynamics, attributes of governance, and capacity to enhance resilience. The Danungdafu Forestation Area represents one of Taiwan’s most controvisal cases concerning land use, indigenous rights, and environmental issues. Analysis of this Taiwanese experience from a social-ecological perspective can show how current capacities for managing resilience are related to critical governance attributes. Analysis helped identify fundamental flaws in current governance and key issues needing to be addressed. The Danungdafu Forestation Area should transition towards a governance regime that is more participatory, deliberative, multi-layered, accountable, just, and networked. This can be done by developing an intermediate level institution that coordinates the cross-scale and cross-level interactions that better fit this social-ecological system.

Integrating adaptive governance and participatory multicriteria methods: a framework for climate adaptation governance

Directory of Open Access Journals (Sweden)

Stefania Munaretto

2014-06-01

Full Text Available Climate adaptation is a dynamic social and institutional process where the governance dimension is receiving growing attention. Adaptive governance is an approach that promises to reduce uncertainty by improving the knowledge base for decision making. As uncertainty is an inherent feature of climate adaptation, adaptive governance seems to be a promising approach for improving climate adaptation governance. However, the adaptive governance literature has so far paid little attention to decision-making tools and methods, and the literature on the governance of adaptation is in its infancy in this regard. We argue that climate adaptation governance would benefit from systematic and yet flexible decision-making tools and methods such as participatory multicriteria methods for the evaluation of adaptation options, and that these methods can be linked to key adaptive governance principles. Moving from these premises, we propose a framework that integrates key adaptive governance features into participatory multicriteria methods for the governance of climate adaptation.

Corporate Governance in Publicly Traded Canadian Companies

OpenAIRE

Hu, Jie; Wang, Chong

2011-01-01

We investigate the effectiveness of corporate governance practices in this paper, focusing on the corporate governance practices implemented by TSX listed companies in Canada. We analyze the determinants of the effectiveness of corporate governance practices and test whether corporate governance mechanisms relate to quality of accounting earnings and company performance. We obtain mixed results from regression analyses indicating that corporate governance mechanisms are not significantly rela...

Air rudder mechanism dynamics considering two elements:Joint clearance and link flexibility

Energy Technology Data Exchange (ETDEWEB)

Li, Yuntao; Quan, Qiquan; Li, He; Tang, Dewei; Li, Zhonghong; Fan, Wenyang; Deng, Zongquan [Harbin Institute of Technology, Harbin (China)

2017-07-15

Both the impact phenomenon in the clearance revolute joint and the link deformation will influence the dynamics of the air rudder transmission mechanism, which could reduce the flight quality of an aircraft. Given the effect of the two elements, a feasible simulation method with two improvements of previous methods is proposed to analyze the dynamic characteristics of the mechanism. In previous studies, the parameters of the contact force model in multi-body dynamics software were generally determined by experience, which may cause uncertainty in the calculation precision of the contact force. Furthermore, it is difficult to solve for the elastic link deformation in the practical mechanism using the available analytical methods due to the complicated section of the link. In this paper, a Continuous contact force (CCF) model was proposed and embedded in the ADAMS by developing a routine of the CCF model. Then, the flexible model was obtained by ANSYS to obtain the elastic link deformation. The experimental results indicate that the proposed simulation method can be effectively applied to predict the dynamic behavior of the mechanism.

Visualization in mechanics: the dynamics of an unbalanced roller

Science.gov (United States)

Cumber, Peter S.

2017-04-01

It is well known that mechanical engineering students often find mechanics a difficult area to grasp. This article describes a system of equations describing the motion of a balanced and an unbalanced roller constrained by a pivot arm. A wide range of dynamics can be simulated with the model. The equations of motion are embedded in a graphical user interface for its numerical solution in MATLAB. This allows a student's focus to be on the influence of different parameters on the system dynamics. The simulation tool can be used as a dynamics demonstrator in a lecture or as an educational tool driven by the imagination of the student. By way of demonstration the simulation tool has been applied to a range of roller-pivot arm configurations. In addition, approximations to the equations of motion are explored and a second-order model is shown to be accurate for a limited range of parameters.

Deformation mechanisms in nanotwinned copper by molecular dynamics simulation

Energy Technology Data Exchange (ETDEWEB)

Zhao, Xing [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083 (China); Lu, Cheng, E-mail: chenglu@uow.edu.au [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Tieu, Anh Kiet; Pei, Linqing; Zhang, Liang; Su, Lihong [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Zhan, Lihua [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083 (China)

2017-02-27

Nanotwinned materials exhibit simultaneous ultrahigh strength and high ductility which is attributed to the interactions between dislocations and twin boundaries but the specific deformation mechanisms are rarely seen in experiments at the atomic level. Here we use large scale molecular dynamics simulations to explore this intricate interplay during the plastic deformation of nanotwinned Cu. We demonstrate that the dominant deformation mechanism transits dynamically from slip transfer to twin boundary migration to slip-twin interactions as the twin boundary orientation changes from horizontal to slant, and then to a vertical direction. Building on the fundamental physics of dislocation processes from computer simulations and combining the available experimental investigations, we unravel the underlying deformation mechanisms for nanotwinned Cu, incorporating all three distinct dislocation processes. Our results give insights into systematically engineering the nanoscale twins to fabricate nanotwinned metals or alloys that have high strength and considerable ductility.

Water, Resilience and the Law: From General Concepts and Governance Design Principles to Actionable Mechanisms

Science.gov (United States)

Hill Clarvis, M.; Allan, A.; Hannah, D. M.

2013-12-01

Climate change has significant ramifications for water law and governance, yet, there is strong evidence that legal regulations have often failed to protect environments or promote sustainable development. Scholars have increasingly suggested that the preservation and restoration paradigms of legislation and regulation are no longer adequate for climate change related challenges in complex and cross-scale social-ecological systems. This is namely due to past assumptions of stationarity, uniformitarianism and the perception of ecosystem change as predictable and reversible. This paper reviews the literature on law and resilience and then presents and discusses a set of practical examples of legal mechanisms from the water resources management sector, identified according to a set of guiding principles from the literature on adaptive capacity, adaptive governance as well as adaptive and integrated water resources management. It then assesses the aptness of these different measures according to scientific evidence of increased uncertainty and changing ecological baselines. A review of the best practice examples demonstrates that there are a number of best practice examples attempting to integrate adaptive elements of flexibility, iterativity, connectivity and subsidiarity into a variety of legislative mechanisms, suggesting that there is not as significant a tension between resilience and the law as many scholars have suggested. However, while many of the mechanisms may indeed be suitable for addressing challenges relating to current levels of change and uncertainty, analysis across a broader range of uncertainty highlights challenges relating to more irreversible changes associated with greater levels of warming. Furthermore the paper identifies a set of pre-requisites that are fundamental to the successful implementation of such mechanisms, namely monitoring and data sharing, financial and technical capacity, particularly in nations that are most at risk with the

Circuit Mechanisms Governing Local vs. Global Motion Processing in Mouse Visual Cortex

DEFF Research Database (Denmark)

Rasmussen, Rune; Yonehara, Keisuke

2017-01-01

components represented by component direction-selective (CDS) cells. However, how PDS and CDS cells develop their distinct response properties is still unresolved. The visual cortex of the mouse is an attractive model for experimentally solving this issue due to the large molecular and genetic toolbox...... literature on global motion processing based on works in primates and mice. Lastly, we propose what types of experiments could illuminate what circuit mechanisms are governing cortical global visual motion processing. We propose that PDS cells in mouse visual cortex appear as the perfect arena...

Governance: Blending Bureaucratic Rules with Day to Day Operational Realities Comment on "Governance, Government, and the Search for New Provider Models".

Science.gov (United States)

Chinitz, David P

2016-05-31

Richard Saltman and Antonio Duran take up the challenging issue of governance in their article "Governance, Government and the Search for New Provider Models," and use two case studies of health policy changes in Sweden and Spain to shed light on the subject. In this commentary, I seek to link their conceptualization of governance, especially its interrelated roles at the macro, meso, and micro levels of health systems, with the case studies on which they report. While the case studies focus on the shifts in governance between the macro and meso levels and their impacts on achievement of desired policy outcomes, they also highlight the need to better integrate the dynamics of day to day operations within micro organizations into the overall governance picture. © 2016 by Kerman University of Medical Sciences.

Broken dynamical symmetries in quantum mechanics and phase transition phenomena

International Nuclear Information System (INIS)

Guenther, N.J.

1979-12-01

This thesis describes applications of dynamical symmetries to problems in quantum mechanics and many-body physics where the latter is formulated as a Euclidean scalar field theory in d-space dimensions. By invoking the concept of a dynamical symmetry group a unified understanding of apparently disparate results is achieved. (author)

The formulation of dynamical contact problems with friction in the case of systems of rigid bodies and general discrete mechanical systems—Painlevé and Kane paradoxes revisited

Science.gov (United States)

Charles, Alexandre; Ballard, Patrick

2016-08-01

The dynamics of mechanical systems with a finite number of degrees of freedom (discrete mechanical systems) is governed by the Lagrange equation which is a second-order differential equation on a Riemannian manifold (the configuration manifold). The handling of perfect (frictionless) unilateral constraints in this framework (that of Lagrange's analytical dynamics) was undertaken by Schatzman and Moreau at the beginning of the 1980s. A mathematically sound and consistent evolution problem was obtained, paving the road for many subsequent theoretical investigations. In this general evolution problem, the only reaction force which is involved is a generalized reaction force, consistently with the virtual power philosophy of Lagrange. Surprisingly, such a general formulation was never derived in the case of frictional unilateral multibody dynamics. Instead, the paradigm of the Coulomb law applying to reaction forces in the real world is generally invoked. So far, this paradigm has only enabled to obtain a consistent evolution problem in only some very few specific examples and to suggest numerical algorithms to produce computational examples (numerical modeling). In particular, it is not clear what is the evolution problem underlying the computational examples. Moreover, some of the few specific cases in which this paradigm enables to write down a precise evolution problem are known to show paradoxes: the Painlevé paradox (indeterminacy) and the Kane paradox (increase in kinetic energy due to friction). In this paper, we follow Lagrange's philosophy and formulate the frictional unilateral multibody dynamics in terms of the generalized reaction force and not in terms of the real-world reaction force. A general evolution problem that governs the dynamics is obtained for the first time. We prove that all the solutions are dissipative; that is, this new formulation is free of Kane paradox. We also prove that some indeterminacy of the Painlevé paradox is fixed in this

Multiphase Flow Dynamics 2 Mechanical Interactions

CERN Document Server

Kolev, Nikolay Ivanov

2012-01-01

Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. .In its fourth extended edition the successful monograph package “Multiphase Flow Daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present second volume the methods for describing the mechanical interactions in multiphase dynamics are provided. This fourth edition includes various updates, extensions, improvements and corrections.   "The literature in the field of multiphase flows is numerous. Therefore, it i...

The importance and role of the corporate governance mechanism in increasing the level of management efficiency

Directory of Open Access Journals (Sweden)

Đorđević Slaviša

2012-01-01

Full Text Available There is inherent conflict of interests between owners and managers. They try to solve it in different ways. In this paper we have tried to briefly introduce the most important internal mechanisms of corporate governance (monitoring by the board of directors, incentive system for managers, internal audit and the importance of institutional investors. The financial scandals that included the world-famous corporations as well as current world economic crisis suggests that the protection of owners should continue to work to improve existing or new solutions that will improve the level of corporate governance.

Dynamic contact angle of water-based titanium oxide nanofluid

Science.gov (United States)

2013-01-01

This paper presents an investigation into spreading dynamics and dynamic contact angle of TiO2-deionized water nanofluids. Two mechanisms of energy dissipation, (1) contact line friction and (2) wedge film viscosity, govern the dynamics of contact line motion. The primary stage of spreading has the contact line friction as the dominant dissipative mechanism. At the secondary stage of spreading, the wedge film viscosity is the dominant dissipative mechanism. A theoretical model based on combination of molecular kinetic theory and hydrodynamic theory which incorporates non-Newtonian viscosity of solutions is used. The model agreement with experimental data is reasonable. Complex interparticle interactions, local pinning of the contact line, and variations in solid–liquid interfacial tension are attributed to errors. PMID:23759071

Socio-ecological dynamics and challenges to the governance of Neglected Tropical Disease control.

Science.gov (United States)

Michael, Edwin; Madon, Shirin

2017-02-06

The current global attempts to control the so-called "Neglected Tropical Diseases (NTDs)" have the potential to significantly reduce the morbidity suffered by some of the world's poorest communities. However, the governance of these control programmes is driven by a managerial rationality that assumes predictability of proposed interventions, and which thus primarily seeks to improve the cost-effectiveness of implementation by measuring performance in terms of pre-determined outputs. Here, we argue that this approach has reinforced the narrow normal-science model for controlling parasitic diseases, and in doing so fails to address the complex dynamics, uncertainty and socio-ecological context-specificity that invariably underlie parasite transmission. We suggest that a new governance approach is required that draws on a combination of non-equilibrium thinking about the operation of complex, adaptive, systems from the natural sciences and constructivist social science perspectives that view the accumulation of scientific knowledge as contingent on historical interests and norms, if more effective control approaches sufficiently sensitive to local disease contexts are to be devised, applied and managed. At the core of this approach is an emphasis on the need for a process that assists with the inclusion of diverse perspectives, social learning and deliberation, and a reflexive approach to addressing system complexity and incertitude, while balancing this flexibility with stability-focused structures. We derive and discuss a possible governance framework and outline an organizational structure that could be used to effectively deal with the complexity of accomplishing global NTD control. We also point to examples of complexity-based management structures that have been used in parasite control previously, which could serve as practical templates for developing similar governance structures to better manage global NTD control. Our results hold important wider

Dynamical mechanism of atrial fibrillation: A topological approach

Science.gov (United States)

Marcotte, Christopher D.; Grigoriev, Roman O.

2017-09-01

While spiral wave breakup has been implicated in the emergence of atrial fibrillation, its role in maintaining this complex type of cardiac arrhythmia is less clear. We used the Karma model of cardiac excitation to investigate the dynamical mechanisms that sustain atrial fibrillation once it has been established. The results of our numerical study show that spatiotemporally chaotic dynamics in this regime can be described as a dynamical equilibrium between topologically distinct types of transitions that increase or decrease the number of wavelets, in general agreement with the multiple wavelets' hypothesis. Surprisingly, we found that the process of continuous excitation waves breaking up into discontinuous pieces plays no role whatsoever in maintaining spatiotemporal complexity. Instead, this complexity is maintained as a dynamical balance between wave coalescence—a unique, previously unidentified, topological process that increases the number of wavelets—and wave collapse—a different topological process that decreases their number.

Governance: Blending Bureaucratic Rules with Day to Day Operational Realities; Comment on “Governance, Government, and the Search for New Provider Models”

Directory of Open Access Journals (Sweden)

David P Chinitz

2016-09-01

Full Text Available Richard Saltman and Antonio Duran take up the challenging issue of governance in their article “Governance, Government and the Search for New Provider Models,” and use two case studies of health policy changes in Sweden and Spain to shed light on the subject. In this commentary, I seek to link their conceptualization of governance, especially its interrelated roles at the macro, meso, and micro levels of health systems, with the case studies on which they report. While the case studies focus on the shifts in governance between the macro and meso levels and their impacts on achievement of desired policy outcomes, they also highlight the need to better integrate the dynamics of day to day operations within micro organizations into the overall governance picture.

Dynamical mechanisms for sensitive response of aperiodic firing cells to external stimulation

International Nuclear Information System (INIS)

Xie Yong; Xu Jianxue; Hu Sanjue; Kang Yanmei; Yang Hongjun; Duan Yubin

2004-01-01

An interesting phenomenon that aperiodic firing neurons have a higher sensitivity to drugs than periodic firing neurons have been reported for the chronically compressed dorsal root ganglion neurons in rats. In this study, the dynamical mechanisms for such a phenomenon are uncovered from the viewpoint of dynamical systems theory. We use the Rose-Hindmarsh neuron model to illustrate our opinions. Periodic orbit theory is introduced to characterize the dynamical behavior of aperiodic firing neurons. It is considered that bifurcations, crises and sensitive dependence of chaotic motions on control parameters can be the underlying mechanisms. And then, a similar analysis is applied to the modified Chay model describing the firing behavior of pancreatic beta cells. The same dynamical mechanisms can be obtained underlying that aperiodic firing cells are more sensitive to external stimulation than periodic firing ones. As a result, we conjecture that sensitive response of aperiodic firing cells to external stimulation is a universal property of excitable cells

Conformation analysis of trehalose. Molecular dynamics simulation and molecular mechanics

International Nuclear Information System (INIS)

Donnamaira, M.C.; Howard, E.I.; Grigera, J.R.

1992-09-01

Conformational analysis of the disaccharide trehalose is done by molecular dynamics and molecular mechanics. In spite of the different force fields used in each case, comparison between the molecular dynamics trajectories of the torsional angles of glycosidic linkage and energy conformational map shows a good agreement between both methods. By molecular dynamics it is observed a moderate mobility of the glycosidic linkage. The demands of computer time is comparable in both cases. (author). 6 refs, 4 figs

An Analysis of Change Mechanisms in Government Budgets on Science and Technology

Science.gov (United States)

Jung, C.

2012-12-01

Recent studies on policy changes have shown that there are limitations of incrementalism and that there no longer exists a general theory that can explain policy change. A number of studies have been conducted to examine policy changes in terms of drastic changes in budgets or policy agenda. According to the Punctuated Equilibrium Theory (PET), policy change is punctuated by long periods of stability, and large, but rare, changes due to shifts in society or the government. Although the reasons for these drastic changes are interpreted mainly from external events, the exact mechanisms of these changes are still not known. In this study, we assume that the punctuated budget changes are a result of not only external events but also the bureaucratic power of government departments. We attempt to identify the regularity of budget change pattern due to these internal characteristics (bureaucratic power). In order to understand budget changes caused by external events, especially for science and technology, the ARIMA-Intervention analysis was implemented. The results showed that the ARIMA-Intervention analysis explained the abrupt change in budget well. This means that a change in budget cannot be explained as incrementalism. Also, we analyzed the budget change kurtosis of government department along with various policy and organization types. Normally, a high kurtosis means there is a high probability of a punctuated equilibrium. The results show that science and technology agency as well as productive, delivery, and transfer agencies have a relatively high kurtosis.;

Dynamic load-balancing-extended gradient mechanism: Graphic representation

International Nuclear Information System (INIS)

Muniz, Francisco J.

2017-01-01

Load-balancing methods are quite well described in the open literature (hundreds of articles can be found about this subject). In particularly, about the Dynamic Load-balancing mechanism Extended Gradient (EG), several articles of the author are available. Even though, there are some overlap, each one of them is focused on a particular aspect of the mechanism, in a complementary way. In this article, a graphic representation of the Extended Gradient mechanism is done: this representation way had not yet been explored. However, for an in-depth knowledge of the Extended Gradient mechanism, at least, some other articles should to be read. In the CDTN, Clusters are used, mainly, in deterministic methods (CFD) and non-deterministic methods (Monte Carlo). (author)

Dynamic load-balancing-extended gradient mechanism: Graphic representation

Energy Technology Data Exchange (ETDEWEB)

Muniz, Francisco J., E-mail: muniz@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Load-balancing methods are quite well described in the open literature (hundreds of articles can be found about this subject). In particularly, about the Dynamic Load-balancing mechanism Extended Gradient (EG), several articles of the author are available. Even though, there are some overlap, each one of them is focused on a particular aspect of the mechanism, in a complementary way. In this article, a graphic representation of the Extended Gradient mechanism is done: this representation way had not yet been explored. However, for an in-depth knowledge of the Extended Gradient mechanism, at least, some other articles should to be read. In the CDTN, Clusters are used, mainly, in deterministic methods (CFD) and non-deterministic methods (Monte Carlo). (author)

The physics of quantum mechanics

CERN Document Server

Binney, James

2014-01-01

The Physics of Quantum Mechanics aims to give students a good understanding of how quantum mechanics describes the material world. It shows that the theory follows naturally from the use of probability amplitudes to derive probabilities. It stresses that stationary states are unphysical mathematical abstractions that enable us to solve the theory's governing equation, the time-dependent Schroedinger equation. Every opportunity is taken to illustrate the emergence of the familiarclassical, dynamical world through the quantum interference of stationary states. The text stresses the continuity be

Hamiltonian mechanics limits microscopic engines

Science.gov (United States)

Anglin, James; Gilz, Lukas; Thesing, Eike

2015-05-01

We propose a definition of fully microscopic engines (micro-engines) in terms of pure mechanics, without reference to thermodynamics, equilibrium, or cycles imposed by external control, and without invoking ergodic theory. This definition is pragmatically based on the observation that what makes engines useful is energy transport across a large ratio of dynamical time scales. We then prove that classical and quantum mechanics set non-trivial limits-of different kinds-on how much of the energy that a micro-engine extracts from its fuel can be converted into work. Our results are not merely formal; they imply manageable design constraints on micro-engines. They also suggest the novel possibility that thermodynamics does not emerge from mechanics in macroscopic regimes, but rather represents the macroscopic limit of a generalized theory, valid on all scales, which governs the important phenomenon of energy transport across large time scale ratios. We propose experimental realizations of the dynamical mechanisms we identify, with trapped ions and in Bose-Einstein condensates (``motorized bright solitons'').

The Role of Corporate Governance in Firm Performance

OpenAIRE

Naimah Zahroh; Hamidah

2017-01-01

The objective of this study is to examine the role of corporate governance to increase firm performance. The measure of corporate governance are corporate governance mechanism and Corporate Governance Perception Index (CGPI). Samples are companies that followed CGPI award at 2005-2014. The examination of the relationship of corporate governance and firm performance is conducted by regression of corporate governance mechanism variables and control variables to profitability. Corporate governan...

Damping capacity and dynamic mechanical characteristics of the plasma-sprayed coatings

International Nuclear Information System (INIS)

Yu Liming; Ma Yue; Zhou Chungen; Xu Huibin

2005-01-01

The damping properties and dynamic mechanical performance of NiCrAlY coating, FeCrMo ferromagnetic coating, AlCuFeCr quasicrystalline coating and nanostructured ZrO 2 ceramic coating, which were prepared by plasma-spray method, were investigated. The measuring results of the dynamic mechanical thermal analyzer (DMTA) and the flexural resonance testing method show that the damping capacity (Q -1 ) of the coated sample has a notable improvement compared to the substrate, while the dynamic modulus has a dramatic decrease. The resonance frequency of the coated cantilever beam structure shifted to high-frequency, and the resonance amplitude, especially high mode resonance, was dramatically attenuated. The internal friction peaks were observed in the Q -1 -temperature spectrogram and a normal amplitude effects were shown in the coated samples damping characteristics. The damping mechanism based on the interaction between substrate and coating layer, and the microstructure of the coated sample were also discussed in this paper

Quantum dynamics in regions of quaternionic curvature

International Nuclear Information System (INIS)

Brumby, S.P.; Joshi, G.

1994-01-01

The complex unit appearing in the equations of quantum mechanics is generalised to a quaternionic structure on spacetime, leading to the consideration of complex quantum mechanical particles whose dynamical behaviour is governed by inhomogeneous Dirac and Schroedinger equations. Mixing of hyper-complex components of wavefunctions occurs through their interaction with potentials dissipative into the extra quaternionic degrees of freedom. An interferometric experiment is analysed to illustrate the effect. 11 refs

The mechanisms of corporate governance in the United States: an assessment

Directory of Open Access Journals (Sweden)

Aldrighi Dante Mendes

2003-01-01

Full Text Available This paper aims at evaluating the mechanisms of corporate governance currently at work in the United States. Section 1 turns its focus to the reasons accounting for the still relative scarceness of large shareholders in American publicly held companies. The analysis thereafter concentrates on assessing the efficacy of each of the pillars purportedly buttressing the American system of corporate control. The paper argues that the evidence provided by the existing corporate governance literature supports the following propositions: 1 the legal and regulatory framework actually restrains the scope for expropriating minority shareholders, though at the cost of inhibiting institutional investor activism; 2 as a rule, the board of directors do not comply with their mandatory duty of overseeing management, although some progress has recently been made, with directors in several companies becoming less submissive to chief executive officers; 3 the market for corporate control encounters a great number of difficulties (ranging from legal hurdles to high transaction costs and to serious free-riding problems, which are sufficient to cast a cloud on its reliability as a means of repressing managerial inefficiencies and rent-seeking; 4 competition in the product and capital markets is likely to produce effects only in the long-run.

Dynamic Relationships in E-Government Initiatives

DEFF Research Database (Denmark)

Mûller, Sune Dueholm; Kræmmergaard, Pernille; Reinwald, Anja Kaldahl

2012-01-01

– depending on the level of involvement (arm’s-length versus embedded) and the envisioned role of IT (management versus leadership). The model is a powerful vehicle for understanding and possibly changing the relationships depending on the needs and visions of the organization wanting to increase its e-government...

Floating clamping mechanism of PT fuel injector and its dynamic characteristics analysis

Science.gov (United States)

Wang, Xinqing; Liang, Sheng; Xia, Tian; Wang, Dong; Qian, Shuhua

2012-05-01

PT fuel injector is one of the most important parts of modern diesel engine. To satisfy the requirements of the rapid and accurate test of PT fuel injector, the self-adaptive floating clamping mechanism was developed and used in the relevant bench. Its dynamic characteristics directly influence the test efficiency and accuracy. However, due to its special structure and complex oil pressure signal, related documents for evaluating dynamic characteristics of this mechanism are lack and some dynamic characteristics of this mechanism can't be extracted and recognized effectively by traditional methods. Aiming at the problem above-mentioned, a new method based on Hilbert-Huang transform (HHT) is presented. Firstly, combining with the actual working process, the dynamic liquid pressure signal of the mechanism is acquired. By analyzing the pressure fluctuation during the whole working process in time domain, oil leakage and hydraulic shock in the clamping chamber are discovered. Secondly, owing to the nonlinearity and nonstationarity of pressure signal, empirical mode decomposition is used, and the signal is decomposed and reconstructed into forced vibration, free vibration and noise. By analyzing forced vibration in the time domain, machining error and installation error of cam are revealed. Finally, free vibration component is analyzed in time-frequency domain with HHT, the traits of free vibration in the time-frequency domain are revealed. Compared with traditional methods, Hilbert spectrum has higher time-frequency resolutions and higher credibility. The improved mechanism based on the above analyses can guarantee the test accuracy of injector injection. This new method based on the analyses of the pressure signal and combined with HHT can provide scientific basis for evaluation, design improvement of the mechanism, and give references for dynamic characteristics analysis of the hydraulic system in the interrelated fields.

On the dynamic mechanical property and deformation mechanism of as-extruded Mg-Sn-Ca alloys under tension

International Nuclear Information System (INIS)

Huang, Qiuyan; Pan, Hucheng; Tang, Aitao; Ren, Yuping; Song, Bo; Qin, Gaowu; Zhang, Mingxing; Pan, Fusheng

2016-01-01

To further understand the deformation mechanism of magnesium alloys and expand their applications under dynamic conditions, the newly developed Mg-2Sn-1Ca alloy (TX21) is selected as the representative sample and tested under wide loading rate ranging from quasi-static to dynamic level (10"−"3–500/s). Both ultimate tensile strength and elongation of the as-extruded TX21 alloys increase with strain rate. Although twinning is accompanied due to the enhanced activity at higher strain rate, the preferential activation of dislocations is readily clarified and confirmed as the dominant deformation modes. Active interactions of pyramidal dislocations result in the higher strain hardening ability and could be correlated to the obviously positive strain-rate sensitivity for mechanical properties. Moreover, it is observed that the larger grain size and higher content of solute atoms dissolved in matrix would lead to the more active dislocations and twinning formations. The present results would provide insight into further understanding the deformation mechanism under dynamic rate loading and designing Mg alloy suitable for impact conditions.

On the dynamic mechanical property and deformation mechanism of as-extruded Mg-Sn-Ca alloys under tension

Energy Technology Data Exchange (ETDEWEB)

Huang, Qiuyan [National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Pan, Hucheng [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Tang, Aitao, E-mail: tat@cqu.edu.cn [National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Ren, Yuping [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Song, Bo [Faculty of Materials and Energy, Southwest University, Chongqing 400715 (China); Qin, Gaowu, E-mail: qingw@smm.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819 (China); Zhang, Mingxing [School of Mechanical and Mining Engineering, University of Queensland, St Lucia, QLD 4072 (Australia); Pan, Fusheng [National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China)

2016-05-10

To further understand the deformation mechanism of magnesium alloys and expand their applications under dynamic conditions, the newly developed Mg-2Sn-1Ca alloy (TX21) is selected as the representative sample and tested under wide loading rate ranging from quasi-static to dynamic level (10{sup −3}–500/s). Both ultimate tensile strength and elongation of the as-extruded TX21 alloys increase with strain rate. Although twinning is accompanied due to the enhanced activity at higher strain rate, the preferential activation of dislocations is readily clarified and confirmed as the dominant deformation modes. Active interactions of pyramidal dislocations result in the higher strain hardening ability and could be correlated to the obviously positive strain-rate sensitivity for mechanical properties. Moreover, it is observed that the larger grain size and higher content of solute atoms dissolved in matrix would lead to the more active dislocations and twinning formations. The present results would provide insight into further understanding the deformation mechanism under dynamic rate loading and designing Mg alloy suitable for impact conditions.

Deformation mechanisms of bent Si nanowires governed by the sign and magnitude of strain

Energy Technology Data Exchange (ETDEWEB)

Wang, Lihua, E-mail: wlh@bjut.edu.cn, E-mail: xdhan@bjut.edu.cn, E-mail: j.zou@uq.edu.au [Beijing Key Lab of Microstructure and Property of Advanced Material, Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124 (China); Materials Engineering, The University of Queensland, Brisbane, QLD 4072 (Australia); Kong, Deli; Xin, Tianjiao; Shu, Xinyu; Zheng, Kun; Xiao, Lirong; Sha, Xuechao; Lu, Yan; Han, Xiaodong, E-mail: wlh@bjut.edu.cn, E-mail: xdhan@bjut.edu.cn, E-mail: j.zou@uq.edu.au [Beijing Key Lab of Microstructure and Property of Advanced Material, Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124 (China); Zhang, Ze [Department of Materials Science, Zhejiang University, Hangzhou 310008 (China); Zou, Jin, E-mail: wlh@bjut.edu.cn, E-mail: xdhan@bjut.edu.cn, E-mail: j.zou@uq.edu.au [Materials Engineering, The University of Queensland, Brisbane, QLD 4072 (Australia); Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, QLD 4072 (Australia)

2016-04-11

In this study, the deformation mechanisms of bent Si nanowires are investigated at the atomic scale with bending strain up to 12.8%. The sign and magnitude of the applied strain are found to govern their deformation mechanisms, in which the dislocation types (full or partial dislocations) can be affected by the sign (tensile or compressive) and magnitude of the applied strain. In the early stages of bending, plastic deformation is controlled by 60° full dislocations. As the bending increases, Lomer dislocations can be frequently observed. When the strain increases to a significant level, 90° partial dislocations induced from the tensile surfaces of the bent nanowires are observed. This study provides a deeper understanding of the effect of the sign and magnitude of the bending strain on the deformation mechanisms in bent Si nanowires.

Uncertainty propagation through dynamic models of assemblies of mechanical structures

International Nuclear Information System (INIS)

Daouk, Sami

2016-01-01

When studying the behaviour of mechanical systems, mathematical models and structural parameters are usually considered deterministic. Return on experience shows however that these elements are uncertain in most cases, due to natural variability or lack of knowledge. Therefore, quantifying the quality and reliability of the numerical model of an industrial assembly remains a major question in low-frequency dynamics. The purpose of this thesis is to improve the vibratory design of bolted assemblies through setting up a dynamic connector model that takes account of different types and sources of uncertainty on stiffness parameters, in a simple, efficient and exploitable in industrial context. This work has been carried out in the framework of the SICODYN project, led by EDF R and D, that aims to characterise and quantify, numerically and experimentally, the uncertainties in the dynamic behaviour of bolted industrial assemblies. Comparative studies of several numerical methods of uncertainty propagation demonstrate the advantage of using the Lack-Of-Knowledge theory. An experimental characterisation of uncertainties in bolted structures is performed on a dynamic test rig and on an industrial assembly. The propagation of many small and large uncertainties through different dynamic models of mechanical assemblies leads to the assessment of the efficiency of the Lack-Of-Knowledge theory and its applicability in an industrial environment. (author)

Comparative analysis for low-mass and low-inertia dynamic balancing of mechanisms

NARCIS (Netherlands)

van der Wijk, V.; Demeulenaere, B.; Gosselin, C.M.; Herder, Justus Laurens

2012-01-01

Dynamic balance is an important feature of high speed mechanisms and robotics that need to minimize vibrations of the base. The main disadvantage of dynamic balancing, however, is that it is accompanied with a considerable increase in mass and inertia. Aiming at low-mass and low-inertia dynamic

Simulating molecular mechanisms of the MDM2-mediated regulatory interactions: a conformational selection model of the MDM2 lid dynamics.

Directory of Open Access Journals (Sweden)

Gennady M Verkhivker

Full Text Available Diversity and complexity of MDM2 mechanisms govern its principal function as the cellular antagonist of the p53 tumor suppressor. Structural and biophysical studies have demonstrated that MDM2 binding could be regulated by the dynamics of a pseudo-substrate lid motif. However, these experiments and subsequent computational studies have produced conflicting mechanistic models of MDM2 function and dynamics. We propose a unifying conformational selection model that can reconcile experimental findings and reveal a fundamental role of the lid as a dynamic regulator of MDM2-mediated binding. In this work, structure, dynamics and energetics of apo-MDM2 are studied as a function of posttranslational modifications and length of the lid. We found that the dynamic equilibrium between "closed" and "semi-closed" lid forms may be a fundamental characteristic of MDM2 regulatory interactions, which can be modulated by phosphorylation, phosphomimetic mutation as well as by the lid size. Our results revealed that these factors may regulate p53-MDM2 binding by fine-tuning the thermodynamic equilibrium between preexisting conformational states of apo-MDM2. In agreement with NMR studies, the effect of phosphorylation on MDM2 interactions was more pronounced with the truncated lid variant that favored the thermodynamically dominant closed form. The phosphomimetic mutation S17D may alter the lid dynamics by shifting the thermodynamic equilibrium towards the ensemble of "semi-closed" conformations. The dominant "semi-closed" lid form and weakened dependence on the phosphorylation seen in simulations with the complete lid can provide a rationale for binding of small p53-based mimetics and inhibitors without a direct competition with the lid dynamics. The results suggested that a conformational selection model of preexisting MDM2 states may provide a robust theoretical framework for understanding MDM2 dynamics. Probing biological functions and mechanisms of MDM2

A Practical Quantum Mechanics Molecular Mechanics Method for the Dynamical Study of Reactions in Biomolecules.

Science.gov (United States)

Mendieta-Moreno, Jesús I; Marcos-Alcalde, Iñigo; Trabada, Daniel G; Gómez-Puertas, Paulino; Ortega, José; Mendieta, Jesús

2015-01-01

Quantum mechanics/molecular mechanics (QM/MM) methods are excellent tools for the modeling of biomolecular reactions. Recently, we have implemented a new QM/MM method (Fireball/Amber), which combines an efficient density functional theory method (Fireball) and a well-recognized molecular dynamics package (Amber), offering an excellent balance between accuracy and sampling capabilities. Here, we present a detailed explanation of the Fireball method and Fireball/Amber implementation. We also discuss how this tool can be used to analyze reactions in biomolecules using steered molecular dynamics simulations. The potential of this approach is shown by the analysis of a reaction catalyzed by the enzyme triose-phosphate isomerase (TIM). The conformational space and energetic landscape for this reaction are analyzed without a priori assumptions about the protonation states of the different residues during the reaction. The results offer a detailed description of the reaction and reveal some new features of the catalytic mechanism. In particular, we find a new reaction mechanism that is characterized by the intramolecular proton transfer from O1 to O2 and the simultaneous proton transfer from Glu 165 to C2. Copyright © 2015 Elsevier Inc. All rights reserved.

Corporate governance and liquidity

DEFF Research Database (Denmark)

Farooq, Omar; Derrabi, Mohamed; Naciri, Monir

2012-01-01

This paper examines the impact of corporate governance mechanisms on liquidity in the MENA region, i.e. Morocco, Egypt, Saudi Arabia, United Arab Emirates, Jordan, Kuwait, and Bahrain. Using turnover as a proxy for liquidity, we document significant difference in liquidity between the pre......- and the post-crisis periods in the MENA region. In addition, our results show that bulk of this reduction in turnover can be explained due to weaknesses of corporate governance mechanisms. For example, that dividend payout ratio and choice of auditors – proxies for agency problems – can explain the entire...... difference in liquidity between the two periods. Furthermore, our results indicate that more than 50% of this difference between the two periods can be explained by operational and informational complexity of a firm – proxy for transparency. We argue that poor corporate governance mechanisms increase...

Competition between Bending and Internal Pressure Governs the Mechanics of Fluid Nanovesicles.

Science.gov (United States)

Vorselen, Daan; MacKintosh, Fred C; Roos, Wouter H; Wuite, Gijs J L

2017-03-28

Nanovesicles (∼100 nm) are ubiquitous in cell biology and an important vector for drug delivery. Mechanical properties of vesicles are known to influence cellular uptake, but the mechanism by which deformation dynamics affect internalization is poorly understood. This is partly due to the fact that experimental studies of the mechanics of such vesicles remain challenging, particularly at the nanometer scale where appropriate theoretical models have also been lacking. Here, we probe the mechanical properties of nanoscale liposomes using atomic force microscopy (AFM) indentation. The mechanical response of the nanovesicles shows initial linear behavior and subsequent flattening corresponding to inward tether formation. We derive a quantitative model, including the competing effects of internal pressure and membrane bending, that corresponds well to these experimental observations. Our results are consistent with a bending modulus of the lipid bilayer of ∼14k b T. Surprisingly, we find that vesicle stiffness is pressure dominated for adherent vesicles under physiological conditions. Our experimental method and quantitative theory represents a robust approach to study the mechanics of nanoscale vesicles, which are abundant in biology, as well as being of interest for the rational design of liposomal vectors for drug delivery.

Mechanical properties of irradiated materials

International Nuclear Information System (INIS)

Robertson, I.M.; Robach, J.; Wirth, B.

2001-01-01

The effect of irradiation on the mechanical properties of metals is considered with particular attention being paid to the development of defect-free channels following uniaxial tensile loading. The in situ transmission electron microscope deformation technique is coupled with dislocation dynamic computer simulations to reveal the fundamental processes governing the elimination of defects by glissile dislocations. The observations of preliminary experiments are reported.(author)

Mechanism for Corrective Action on Budget Imbalances

Directory of Open Access Journals (Sweden)

Ion Lucian CATRINA

2014-02-01

Full Text Available The European Fiscal Compact sets the obligation for the signatory states to establish an automatic mechanism for taking corrective action on budget imbalances. Nevertheless, the European Treaty says nothing about the tools that should be used in order to reach the desired equilibrium of budgets, but only that it should aim at correcting deviations from the medium-term objective or the adjustment path, including their cumulated impact on government debt dynamics. This paper is aiming at showing that each member state has to build the correction mechanism according to the impact of the chosen tools on economic growth and on general government revenues. We will also emphasize that the correction mechanism should be built not only exacerbating the corrective action through spending/ tax based adjustments, but on a high quality package of economic policies as well.

Synoptic-scale analysis of mechanisms driving surface chlorophyll dynamics in the North Atlantic

Directory of Open Access Journals (Sweden)

A. S. A. Ferreira

2015-06-01

Full Text Available Several hypotheses have been proposed for the onset of the spring phytoplankton bloom in the North Atlantic. Our main objective is to examine which bottom-up processes can best predict the annual increase in surface phytoplankton concentration in the North Atlantic by applying novel phenology algorithms to ocean colour data. We construct indicator fields and time series which, in various combinations, provide models consistent with the principle dynamics previously proposed. Using a multimodel inference approach, we investigate the evidence supporting these models and how it varies in space. We show that, in terms of bottom-up processes alone, there is a dominant physical mechanism, namely mixed-layer shoaling, that best predicts the interannual variation in the initial increase in surface chlorophyll across large sectors of the North Atlantic. We further show that different regions are governed by different physical phenomena and that wind-driven mixing is a common component, with either heat flux or light as triggers. We believe these findings to be relevant to the ongoing discussion on North Atlantic bloom onset.

Mechanical Spectroscopy: Some Applications On Structural Changes And Relaxation Dynamics In Soft Matter

Directory of Open Access Journals (Sweden)

Wu Xuebang

2015-09-01

Full Text Available The general trend in soft matter is to study systems of increasing complexity covering a wide range in time and frequency. Mechanical spectroscopy is a powerful tool for understanding the structure and relaxation dynamics of these materials over a large temperature range and frequency scale. In this work, we collect a few recent applications using low-frequency mechanical spectroscopy for elucidating the structural changes and relaxation dynamics in soft matter, largely based on the author’s group. We illustrate the potential of mechanical spectroscopy with three kinds of soft materials: colloids, polymers and granular systems. Examples include structural changes in colloids, segmental relaxations in amorphous polymers, and resonant dissipation of grain chains in three-dimensional media. The present work shows that mechanical spectroscopy has been applied as a necessary and complementary tool to study the dynamics of such complex systems.

Test methods for the dynamic mechanical properties of polymeric materials. Final report

Energy Technology Data Exchange (ETDEWEB)

Baker, G.K.

1980-06-01

Various test geometries and procedures for the dynamic mechanical analysis of polymers employing a mechanical spectrometer have been evaluated. The methods and materials included in this work are forced torsional pendulum testing of Kevlar/epoxy laminates and rigid urethane foams, oscillatory parallel plate testing to determine the kinetics of the cure of VCE with Hylene MP, oscillatory compressive testing of B-3223 cellular silicone, and oscillatory tensile testing of Silastic E and single Kevlar filaments. Fundamental dynamic mechanical properties, including the storage and loss moduli and loss tangent of the materials tested, were determined as a function of temperature and sometimes of frequency.

Fractional quantum mechanics on networks: Long-range dynamics and quantum transport.

Science.gov (United States)

Riascos, A P; Mateos, José L

2015-11-01

In this paper we study the quantum transport on networks with a temporal evolution governed by the fractional Schrödinger equation. We generalize the dynamics based on continuous-time quantum walks, with transitions to nearest neighbors on the network, to the fractional case that allows long-range displacements. By using the fractional Laplacian matrix of a network, we establish a formalism that combines a long-range dynamics with the quantum superposition of states; this general approach applies to any type of connected undirected networks, including regular, random, and complex networks, and can be implemented from the spectral properties of the Laplacian matrix. We study the fractional dynamics and its capacity to explore the network by means of the transition probability, the average probability of return, and global quantities that characterize the efficiency of this quantum process. As a particular case, we explore analytically these quantities for circulant networks such as rings, interacting cycles, and complete graphs.

Director remuneration, corporate governance and performance: A comparison between government linked companies vs non government linked companies

Directory of Open Access Journals (Sweden)

Nazrul Hisyam Ab Razak

2014-07-01

Full Text Available This study has examined the relationship between director’s remuneration, corporate governance structure and performance of a sample of 150 companies listed on the Bursa Malaysia from year 2008 until 2013. The sample was selected to provide matched-pair of government linked companies (GLCs and non-government linked companies (non-GLCs, as it was anticipated that these group would have different governance structure, the key difference being government ownership. The result holds even when we control for company specific characteristic such as corporate governance, company size, leverage, director’s remuneration, board size and auditors. This study uses panel based regression model to examine the impact of government control mechanism on company performance using two important measurers. These are accounting based measure proxies by ROA and non-accounting based measures by Tobin’s Q. Statistically significant relationships were found across the groupings and for different performance measures. Findings appear to suggest that there is a significant impact of government ownership on company performance after controlling for company specific characteristics.

A variational approach to nonsmooth dynamics applications in unilateral mechanics and electronics

CERN Document Server

Adly, Samir

2017-01-01

This brief examines mathematical models in nonsmooth mechanics and nonregular electrical circuits, including evolution variational inequalities, complementarity systems, differential inclusions, second-order dynamics, Lur'e systems and Moreau's sweeping process. The field of nonsmooth dynamics is of great interest to mathematicians, mechanicians, automatic controllers and engineers. The present volume acknowledges this transversality and provides a multidisciplinary view as it outlines fundamental results in nonsmooth dynamics and explains how to use them to study various problems in engineering. In particular, the author explores the question of how to redefine the notion of dynamical systems in light of modern variational and nonsmooth analysis. With the aim of bridging between the communities of applied mathematicians, engineers and researchers in control theory and nonlinear systems, this brief outlines both relevant mathematical proofs and models in unilateral mechanics and electronics.

The Role of Corporate Governance in Firm Performance

Directory of Open Access Journals (Sweden)

Naimah Zahroh

2017-01-01

Full Text Available The objective of this study is to examine the role of corporate governance to increase firm performance. The measure of corporate governance are corporate governance mechanism and Corporate Governance Perception Index (CGPI. Samples are companies that followed CGPI award at 2005-2014. The examination of the relationship of corporate governance and firm performance is conducted by regression of corporate governance mechanism variables and control variables to profitability. Corporate governance mechanisms are board size, board independence, outside directors, audit committee size, audit committee meeting, audit quality, and CGPI. Control variables are leverage and firm size. The results of this study indicate that board independence negatively influence profitability, audit committee meeting positively influence profitability, audit quality positively influence profitability, CGPI positively influence profitability, leverage negatively influence profitability, and firm size negatively influence profitability.

Dynamic simulation of road vehicle door window regulator mechanism of cross arm type

Science.gov (United States)

Miklos, I. Zs; Miklos, C.; Alic, C.

2017-01-01

The paper presents issues related to the dynamic simulation of a motor-drive operating mechanism of cross arm type, for the manipulation of road vehicle door windows, using Autodesk Inventor Professional software. The dynamic simulation of the mechanism involves a 3D modelling, kinematic coupling, drive motion parameters and external loads, as well as the graphically view of the kinematic and kinetostatic results for the various elements and kinematic couplings of the mechanism, under real operating conditions. Also, based on the results, the analysis of the mechanism components has been carried out using the finite element method.

Measuring Clearance Mechanics Based on Dynamic Leg Length

Science.gov (United States)

Khamis, Sam; Danino, Barry; Hayek, Shlomo; Carmeli, Eli

2018-01-01

The aim of this study was to quantify clearance mechanics during gait. Seventeen children diagnosed with hemiplegic cerebral palsy underwent a three-dimensional gait analysis evaluation. Dynamic leg lengths were measured from the hip joint center to the heel, to the ankle joint center and to the forefoot throughout the gait cycle. Significant…

Dynamic model of Stirling engine crank mechanism with connected electric generator

Directory of Open Access Journals (Sweden)

Vlach R.

2009-06-01

Full Text Available This paper treats of a numerical dynamic model of Stirling engine crank mechanism. The model is included in the complex model of combined heat and power unit. The unit is composed of the Stirling engine and of attached three-phase synchronous generator. This generator should start the Stirling engine in motor mode as well. It is necessary to combine the crank shaft dynamic model and the complete thermal model of Stirling engine for simulations and analyses of engine run. Our aim is to create a dynamics model which takes into account the parameters of crankshaft, piston rods, pistons, and attached generator. For unit working, the electro-mechanical behaviour of generator is also important. That is why we experimentally verified the parameters of generator. The measured characteristics are used in a complex model of heat and power unit. Moreover, it is also possible to determine the Stirling engine torque by the help of these electro-mechanical characteristics. These values can be used e. g. for determination of optimal engine working point or for unit control.

Positive Nonlinear Dynamical Group Uniting Quantum Mechanics and Thermodynamics

OpenAIRE

Beretta, Gian Paolo

2006-01-01

We discuss and motivate the form of the generator of a nonlinear quantum dynamical group 'designed' so as to accomplish a unification of quantum mechanics (QM) and thermodynamics. We call this nonrelativistic theory Quantum Thermodynamics (QT). Its conceptual foundations differ from those of (von Neumann) quantum statistical mechanics (QSM) and (Jaynes) quantum information theory (QIT), but for thermodynamic equilibrium (TE) states it reduces to the same mathematics, and for zero entropy stat...

Security and Peace Mechanisms for Good Governance in Nigeria ...

African Journals Online (AJOL)

In Nigeria, governments at all levels have intensified efforts to address issues bordering on insecurity with a view to building security and peace for good governance. It is however, disheartening that despite various security measures put in place to tackle the problem, Nigeria is yet to be free from recurrent cases of armed ...

Dynamics of polymeric liquids. Vol. 1, 2nd Ed.: Fluid mechanics

International Nuclear Information System (INIS)

Bird, R.B.; Armstrong, R.C.; Hassager, O.

1987-01-01

This book examines Newtonian liquids and polymer fluid mechanics. It begins with a review of the main ideas of fluid dynamics as well as key points of Newtonian fluids. Major revisions include extensive updating of all material and a greater emphasis on fluid dynamics problem solving. It presents summaries of experiments describing the difference between polymeric and simple fluids. In addition, it traces, roughly in historical order, various methods for solving polymer fluid dynamics problems

Governance and management dynamics of landscape restoration at multiple scales: Learning from successful environmental managers in Sweden.

Science.gov (United States)

Dawson, Lucas; Elbakidze, Marine; Angelstam, Per; Gordon, Johanna

2017-07-15

Due to a long history of intensive land and water use, habitat networks for biodiversity conservation are generally degraded in Sweden. Landscape restoration (LR) is an important strategy for achieving representative and functional green infrastructures. However, outcomes of LR efforts are poorly studied, particularly the dynamics of LR governance and management. We apply systems thinking methods to a series of LR case studies to analyse the causal structures underlying LR governance and management in Sweden. We show that these structures appear to comprise of an interlinked system of at least three sets of drivers and four core processes. This system exhibits many characteristics of a transformative change towards an integrated, adaptive approach to governance and management. Key challenges for Swedish LR projects relate to institutional and regulatory flexibility, the timely availability of sufficient funds, and the management of learning and knowledge production processes. In response, successful project leaders develop several key strategies to manage complexity and risk, and enhance perceptions of the attractiveness of LR projects. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effects of oil shocks on government expenditures and government revenues nexus in Iran (as a developing oil-export based economy)

NARCIS (Netherlands)

S.F. Dizaji (Sajjad Faraji)

2012-01-01

textabstractThe main purpose of this study is to investigate the dynamic relationship between government revenues and government expenditures in Iran as a developing oil export based economy. Moreover, I want to know how government expenditures and revenues respond to oil price (revenue) shocks. I

Dynamical mechanism of the liquid film motor

Science.gov (United States)

Liu, Zhong-Qiang; Li, Ying-Jun; Zhang, Guang-Cai; Jiang, Su-Rong

2011-02-01

The paper presents a simple dynamical model to systemically explain the rotation mechanism of the liquid film motor reported by experiments. The field-induced-plasticity effect of the liquid film is introduced into our model, in which the liquid film in crossed electric fields is considered as a Bingham plastic fluid with equivalent electric dipole moment. Several analytic results involving the torque of rotation, the scaling relation of the threshold fields, and the dynamics equation of a square film and its solution are obtained. We find that the rotation of the liquid film motor originates from the continuous competition between the destruction and the reestablishment of the polarization equilibrium maintained by the external electric field, which is free from the boundary effects. Most experimental phenomena observed in direct current electric fields are interpreted well.

An Investigation of the Impact of Corporate Governance Mechanisms on Level of Corporate Risk Disclosure: Evidence from Kuwait

Directory of Open Access Journals (Sweden)

Bader Al-Shammari

2014-06-01

Full Text Available This study investigated the association between corporate governance mechanisms and corporate risk disclosure (CRD in the annual reports for a sample of 109 Kuwaiti listed non-financial companies in 2012. The study used a manual content analysis to measure risk disclosure by counting the number of risk-related sentences in annual reports. A multiple regression analysis was used to test the impact of board size, non-executive directors, percentage of family members on board, role duality, and audit committee on CRD. The quantity of risk disclosures in the Kuwaiti companies' annual reports was very limited. The results showed that the larger board size has a positive impact on CRD. However, the findings also indicated the existence of role duality lead to lower risk disclosure. Other corporate governance mechanisms did not explain variation in CRD.

A concept of dynamic permission mechanism on android

Science.gov (United States)

Aron, Lukas; Hanacek, Petr

2016-02-01

This paper discuss the main security topic in mobile security area and this topic is protect user against the leakage of data. This work primarily contains the proposal of concept of dynamic permission mechanism for Android operating system. This mechanism deals with assignment or enforcement permissions to the application according to files that the application works with. Application has set of permissions that can use, but if the user opens confident files the application permissions should change its permission set and there should not be possible leakage of this secret data. The permissions set should be stricter according to opened confidential file or more open (without restriction) if the file is not secret file. The concept proposes the solution for protecting this data leakage. Idea covers rule that user should be avoided of change this permissions himself, but this behavior should be dynamic, automatic and independent. This proposal is mainly aimed to Android operating system, but the concept can be applied to other mobile platforms with some implementation changes.

Pengaruh Corporate Governance terhadap Efektifitas Mekanisme Pengurang Masalah Agensi

Directory of Open Access Journals (Sweden)

Zaenal Arifin

2009-03-01

Full Text Available The main objective of this research is to investigate whether there are a significant influence between corporate governance and effectiveness of agency-problem-reducing mechanism. The corporate governance is concern on all stakeholder interest while the agency variables are concern only on one of the most important stakeholders’ that is the stockholders. In theory, there should be a significant relationship between the corporate governance and the effectiveness of agency-problem-reducing mechanism. Using all manufacturing companies listed in Jakarta Stock Exchange during 2001 - 2004, this research found that corporate governance influence the effectiveness of debt mechanism in reducing agency problem. The other mechanism, dividend and independent board of director, do not effective to reduce agency problem and the corporate governance does not influence the effectiveness of these two mechanisms. Key words: agency problem, corporate governance, dividend, debt, independent Board of director

Governing Forest Ecosystem Services for Sustainable Environmental Governance: A Review

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Shankar Adhikari

2018-05-01

Full Text Available Governing forest ecosystem services as a forest socio-ecological system is an evolving concept in the face of different environmental and social challenges. Therefore, different modes of ecosystem governance such as hierarchical, scientific–technical, and adaptive–collaborative governance have been developed. Although each form of governance offers important features, no one form on its own is sufficient to attain sustainable environmental governance (SEG. Thus, the blending of important features of each mode of governance could contribute to SEG, through a combination of both hierarchical and collaborative governance systems supported by scientifically and technically aided knowledge. This should be further reinforced by the broad engagement of stakeholders to ensure the improved well-being of both ecosystems and humans. Some form of governance and forest management measures, including sustainable forest management, forest certification, and payment for ecosystem services mechanisms, are also contributing to that end. While issues around commodification and putting a price on nature are still contested due to the complex relationship between different services, if these limitations are taken into account, the governance of forest ecosystem services will serve as a means of effective environmental governance and the sustainable management of forest resources. Therefore, forest ecosystem services governance has a promising future for SEG, provided limitations are tackled with due care in future governance endeavors.

A Multiscale Model for Virus Capsid Dynamics

Directory of Open Access Journals (Sweden)

Changjun Chen

2010-01-01

Full Text Available Viruses are infectious agents that can cause epidemics and pandemics. The understanding of virus formation, evolution, stability, and interaction with host cells is of great importance to the scientific community and public health. Typically, a virus complex in association with its aquatic environment poses a fabulous challenge to theoretical description and prediction. In this work, we propose a differential geometry-based multiscale paradigm to model complex biomolecule systems. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum domain of the fluid mechanical description of the aquatic environment from the microscopic discrete domain of the atomistic description of the biomolecule. A multiscale action functional is constructed as a unified framework to derive the governing equations for the dynamics of different scales. We show that the classical Navier-Stokes equation for the fluid dynamics and Newton's equation for the molecular dynamics can be derived from the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows.

A multiscale model for virus capsid dynamics.

Science.gov (United States)

Chen, Changjun; Saxena, Rishu; Wei, Guo-Wei

2010-01-01

Viruses are infectious agents that can cause epidemics and pandemics. The understanding of virus formation, evolution, stability, and interaction with host cells is of great importance to the scientific community and public health. Typically, a virus complex in association with its aquatic environment poses a fabulous challenge to theoretical description and prediction. In this work, we propose a differential geometry-based multiscale paradigm to model complex biomolecule systems. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum domain of the fluid mechanical description of the aquatic environment from the microscopic discrete domain of the atomistic description of the biomolecule. A multiscale action functional is constructed as a unified framework to derive the governing equations for the dynamics of different scales. We show that the classical Navier-Stokes equation for the fluid dynamics and Newton's equation for the molecular dynamics can be derived from the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows.

How mechanical context and feedback jointly determine the use of mechanical variables in length perception by dynamic touch

NARCIS (Netherlands)

Menger, Rudmer; Withagen, Rob

Earlier studies have revealed that both mechanical context and feedback determine what mechanical invariant is used to perceive length by dynamic touch. In the present article, the authors examined how these two factors jointly constrain the informational variable that is relied upon. Participants

How mechanical context and feedback jointly determine the use of mechanical variables in length perception by dynamic touch

NARCIS (Netherlands)

Menger, Rudmer; Withagen, Rob

2009-01-01

Earlier studies have revealed that both mechanical context and feedback determine what mechanical invariant is used to perceive length by dynamic touch. In the present article, the authors examined how these two factors jointly constrain the informational variable that is relied upon. Participants

Dynamic Mechanical Behaviors of 6082-T6 Aluminum Alloy

Directory of Open Access Journals (Sweden)

Peng Yibo

2013-01-01

Full Text Available The structural components of high speed trains are usually made of aluminum alloys, for example, 6082. The dynamic mechanical behavior of the material is one of key factors considered in structural design and safety assessment. In this paper, dynamic mechanical experiments were conducted with strain rate ranging from 0.001 s−1 to 100 s−1 using Instron tensile testing machine. The true stress-strain curves were fitted based on experimental data. Johnson-Cook model of 6082-T6 aluminum alloy was built to investigate the effect of strain and strain rate on flow stress. It has shown that the flow stress was sensitive to the strain rate. Yield strength and tensile strength increased with a high strain rate, which showed strain rate effect to some extent. Fracture analysis was carried out by using Backscattered Electron imaging (BSE. As strain rate increased, more precipitates were generated in fracture.

Bulk-mediated surface diffusion: non-Markovian desorption dynamics

International Nuclear Information System (INIS)

Revelli, Jorge A; Budde, Carlos E; Prato, Domingo; Wio, Horacio S

2005-01-01

Here we analyse the dynamics of adsorbed molecules within the bulk-mediated surface diffusion framework, when the particle's desorption mechanism is characterized by a non-Markovian process, while the particle's adsorption as well as its motion in the bulk is governed by Markovian dynamics. We study the diffusion of particles in both semi-infinite and finite cubic lattices, analysing the conditional probability to find the system on the reference absorptive plane as well as the surface dispersion as functions of time. The results are compared with known Markovian cases showing the differences that can be exploited to distinguish between Markovian and non-Markovian desorption mechanisms in experimental situations

Experimental research on dynamic mechanical properties of PZT ceramic under hydrostatic pressure

International Nuclear Information System (INIS)

Wang, S.; Liu, K.X.

2011-01-01

Highlights: → We developed an experimental device to examine dynamic mechanical properties of PZT. → Ductile behavior of PZT was seen when hydrostatic pressure was involved. → Compressive strength was shown sensitive to hydrostatic pressure and strain-rate. → A failure criterion was suggested to explain the failure behavior of PZT. - Abstract: An experimental technique for initially applied hydrostatic pressure in specimens subjected to axial impact has been developed to study the dynamic mechanical properties of materials. The technique was employed for the purpose of examining the dynamic mechanical properties of lead zirconate titanate (PZT) at zero to 15 MPa hydrostatic pressures. Experimental results unambiguously exhibit the ductile behavior of PZT when hydrostatic pressure is involved. The compressive strength is demonstrated sensitive to the initial hydrostatic pressure and the strain-rate. The fracture modes are analyzed by means of scanning electron microscopy (SEM). Moreover, a failure criterion based on Mohr-Coulomb failure theory is suggested to explain the brittle and ductile failure of PZT.

Forms of global governence

Directory of Open Access Journals (Sweden)

Maxim V. Kharkevich

2014-01-01

Full Text Available Global governance as a concept defines the meaning of contemporary world politics both as a discipline and as reality. Interdependent and globalized world requires governance, and a global government has not been formed yet. The theoretical possibility of global governance without global government is proved and justified. The purpose of this article is to analytically identify possible forms of global governance. Three such forms of global governance are identified: hierarchical, market and network. In a hierarchy the governance is due to the asymmetry of power between the parties. Market control happens via anonymous pricing mechanism. Network, in contrast to the market is characterized by a closer value link between the actors, but unlike the hierarchical relationship actors are free to leave the network. Global governance takes three forms and is being implemented by different actors. To determine the most efficient form of global governance is impossible. Efficiency depends on the match between a form and an object of government. It should be noted that meta governance is likely to remain a monopoly of institutionally strong states in global governance.

Dynamic behavior of the mechanical systems from the structure of a hybrid automobile

Science.gov (United States)

Dinel, Popa; Irina, Tudor; Nicolae-Doru, Stănescu

2017-10-01

In introduction are presented solutions of planetary mechanisms that can be used in the construction of the hybrid automobiles where the thermal and electrical sources must be coupled. The systems have in their composition a planetary mechanism with two degrees of mobility at which are coupled a thermal engine, two revertible electrical machines, a gear transmission with four gears and a differential mechanism which transmits the motion at the driving wheels. For the study of the dynamical behavior, with numerical results, one designs such mechanisms, models the elements with solids in AutoCAD, and obtains the mechanical properties of the elements. Further on, we present and solve the equations of motion of a hybrid automotive for which one knows the dynamical parameters.

Evaluation of glass transition temperature and dynamic mechanical properties of autopolymerized hard direct denture reline resins.

Science.gov (United States)

Takase, Kazuma; Watanabe, Ikuya; Kurogi, Tadafumi; Murata, Hiroshi

2015-01-01

This study assessed methods for evaluation of glass transition temperature (Tg) of autopolymerized hard direct denture reline resins using dynamic mechanical analysis and differential scanning calorimetry in addition to the dynamic mechanical properties. The Tg values of 3 different reline resins were determined using a dynamic viscoelastometer and differential scanning calorimeter, and rheological parameters were also determined. Although all materials exhibited higher storage modulus and loss modulus values, and a lower loss tangent at 37˚C with a higher frequency, the frequency dependence was not large. Tg values obtained by dynamic mechanical analysis were higher than those by differential scanning calorimetry and higher frequency led to higher Tg, while more stable Tg values were also obtained by that method. These results suggest that dynamic mechanical analysis is more advantageous for characterization of autopolymerized hard direct denture reline resins than differential scanning calorimetry.

Electron beam crosslinked gels-Preparation, characterization and their effect on the mechanical, dynamic mechanical and rheological properties of rubbers

Energy Technology Data Exchange (ETDEWEB)

Mitra, Suman; Chattopadhyay, Santanu [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Sabharwal, Sunil [Radiation Technology Development Section, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.i [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

2010-03-15

Electron beam (EB) crosslinked natural rubber (NR) gels were prepared by curing NR latex with EB irradiation over a range of doses from 2.5 to 20 kGy using butyl acrylate as sensitizer. The NR gels were systematically characterized by solvent swelling, dynamic light scattering, mechanical and dynamic mechanical properties. These gels were introduced in virgin NR and styrene butadiene rubber (SBR) matrices at 2, 4, 8 and 16 phr concentration. Addition of the gels improved the mechanical and dynamic mechanical properties of NR and SBR considerably. For example, 16 phr of 20 kGy EB-irradiated gel-filled NR showed a tensile strength of 3.53 MPa compared to 1.85 MPa of virgin NR. Introduction of gels in NR shifted the glass transition temperature to a higher temperature. A similar effect was observed in the case of NR gel-filled SBR systems. Morphology of the gel-filled systems was studied with atomic force microscopy. The NR gels also improved the processability of the virgin rubbers greatly. Both the shear viscosity and the die swell values of EB-irradiated gel-filled NR and SBR were lower than their virgin counterparts as investigated by capillary rheometer.

Electron beam crosslinked gels-Preparation, characterization and their effect on the mechanical, dynamic mechanical and rheological properties of rubbers

International Nuclear Information System (INIS)

Mitra, Suman; Chattopadhyay, Santanu; Sabharwal, Sunil; Bhowmick, Anil K.

2010-01-01

Electron beam (EB) crosslinked natural rubber (NR) gels were prepared by curing NR latex with EB irradiation over a range of doses from 2.5 to 20 kGy using butyl acrylate as sensitizer. The NR gels were systematically characterized by solvent swelling, dynamic light scattering, mechanical and dynamic mechanical properties. These gels were introduced in virgin NR and styrene butadiene rubber (SBR) matrices at 2, 4, 8 and 16 phr concentration. Addition of the gels improved the mechanical and dynamic mechanical properties of NR and SBR considerably. For example, 16 phr of 20 kGy EB-irradiated gel-filled NR showed a tensile strength of 3.53 MPa compared to 1.85 MPa of virgin NR. Introduction of gels in NR shifted the glass transition temperature to a higher temperature. A similar effect was observed in the case of NR gel-filled SBR systems. Morphology of the gel-filled systems was studied with atomic force microscopy. The NR gels also improved the processability of the virgin rubbers greatly. Both the shear viscosity and the die swell values of EB-irradiated gel-filled NR and SBR were lower than their virgin counterparts as investigated by capillary rheometer.

How Do Corporate Governance Mechanisms Affect A Firm’s Potential For Bankruptcy?

Directory of Open Access Journals (Sweden)

Rhesa Theodorus Hanani

2015-03-01

Full Text Available The purpose of this thesis is to understand the effects of corporate governance mechanisms on the potential for bankruptcy. This study is done by utilizing the linear regression fixed effect vector decomposition model on 30 listed firms from the consumer goods sector of Indonesia Stock Exchange during the 2010-2012 periods. The results of the study indicate that: the board of commissioners’ independence and size of the commissioners’ board pose a significant positive effect on the potential for bankruptcy; the presence of an audit committee and the presence of a nomination and remuneration committee pose a significant negative effect and institutional ownership and managerial ownership do not significantly affect the potential for bankruptcy.

Comparison of phase space dynamics of Kopenhagen and causal interpretations of quantum mechanics

Energy Technology Data Exchange (ETDEWEB)

Tempel, Christoph; Schleich, Wolfgang P. [Institut fuer Quantenphysik, Universitaet Ulm, D-89069 Ulm (Germany)

2013-07-01

Recent publications pursue the attempt to reconstruct Bohm trajectories experimentally utilizing the technique of weak measurements. We study the phase space dynamics of a specific double slit setup in terms of the Bohm de-Broglie formulation of quantum mechanics. We want to compare the results of those Bohmian phase space dynamics to the usual quantum mechanical phase space formulation with the Wigner function as a quasi probability density.

THE MANAGEMENT SUBSIDIARIES: CORPORATE GOVERNANCE MECHANISMS IN GROUP OF COMPANIES

Directory of Open Access Journals (Sweden)

A. K. Tatulyan

2016-01-01

control of subsidiaries, and the effectiveness of corporate governance mechanisms in group of companies.

MATHEMATICAL MODEL FOR ESTIMATION OF MECHANICAL SYSTEM CONDITION IN DYNAMICS

Directory of Open Access Journals (Sweden)

D. N. Mironov

2011-01-01

Full Text Available The paper considers an estimation of a complicated mechanical system condition in dynamics with due account of material degradation and accumulation of micro-damages. An element of continuous medium has been simulated and described with the help of a discrete element. The paper contains description of a model for determination of mechanical system longevity in accordance with number of cycles and operational period.

The governance of clean energy in India: The clean development mechanism (CDM) and domestic energy politics

International Nuclear Information System (INIS)

Phillips, Jon; Newell, Peter

2013-01-01

This paper explores the ways in which clean energy is being governed in India. It does so in order to improve our understanding of the potential and limitations of carbon finance in supporting lower carbon energy transitions, and to strengthen our appreciation of the role of politics in enabling or frustrating such endeavors. In particular we emphasize the importance of politics and the nature of India's political economy in understanding the development of energy sources and technologies defined as ‘clean’ both by the United Nations Clean Development Mechanism (CDM) and leading international actors. By considering the broad range of institutions that exert formal and informal political influence over how the benefits and costs of the CDM are distributed, the paper highlights shortcomings in the narrow way in which CDM governance has been conceptualized to date. This approach goes beyond analysis of technocratic aspects of governance – often reduced to a set of institutional design issues – in order to appreciate the political nature of the trade-offs that characterize debates about India's energy future and the relations of power which will determine how, and on whose terms, they are resolved. - Highlights: • Clean energy governance in practice is shaped by political power and influence. • Governance of clean energy requires strong institutions from local to global levels. • Un-governed areas of energy policy are often as revealing of the exercise of power as areas where there explicit policy is in place. • Climate and carbon finance interventions need to better understand the landscape of political power which characterises India’s energy sector

The mental health care model in Brazil: analyses of the funding, governance processes, and mechanisms of assessment

Directory of Open Access Journals (Sweden)

Thiago Lavras Trapé

Full Text Available ABSTRACT OBJECTIVE This study aims to analyze the current status of the mental health care model of the Brazilian Unified Health System, according to its funding, governance processes, and mechanisms of assessment. METHODS We have carried out a documentary analysis of the ordinances, technical reports, conference reports, normative resolutions, and decrees from 2009 to 2014. RESULTS This is a time of consolidation of the psychosocial model, with expansion of the health care network and inversion of the funding for community services with a strong emphasis on the area of crack cocaine and other drugs. Mental health is an underfunded area within the chronically underfunded Brazilian Unified Health System. The governance model constrains the progress of essential services, which creates the need for the incorporation of a process of regionalization of the management. The mechanisms of assessment are not incorporated into the health policy in the bureaucratic field. CONCLUSIONS There is a need to expand the global funding of the area of health, specifically mental health, which has been shown to be a successful policy. The current focus of the policy seems to be archaic in relation to the precepts of the psychosocial model. Mechanisms of assessment need to be expanded.

Dynamic mechanical analysis of compatibilizer effect on the mechanical properties of wood flour/high-density polyethylene composites

Science.gov (United States)

Mehdi Behzad; Medhi Tajvidi; Ghanbar Ehrahimi; Robert H. Falk

2004-01-01

In this study, effect of MAPE (maleic anhydride polyethylene) as the compatibilizer on the mechanical properties of wood-flour polyethylene composites has been investigated by using Dynamic Mechanical Analysis (DMA). Composites were made at 25% and 50% by weight fiber contents and 1% and 2% compatibilizer respectively. Controls were also made at the same fiber contents...

Characterization of Bitumen Micro-Mechanical Behaviors Using AFM, Phase Dynamics Theory and MD Simulation

Directory of Open Access Journals (Sweden)

Yue Hou

2017-02-01

Full Text Available Fundamental understanding of micro-mechanical behaviors in bitumen, including phase separation, micro-friction, micro-abrasion, etc., can help the pavement engineers better understand the bitumen mechanical performances at macroscale. Recent researches show that the microstructure evolution in bitumen will directly affect its surface structure and micro-mechanical performance. In this study, the bitumen microstructure and micro-mechanical behaviors are studied using Atomic Force Microscopy (AFM experiments, Phase Dynamics Theory and Molecular Dynamics (MD Simulation. The AFM experiment results show that different phase-structure will occur at the surface of the bitumen samples under certain thermodynamic conditions at microscale. The phenomenon can be explained using the phase dynamics theory, where the effects of stability parameter and temperature on bitumen microstructure and micro-mechanical behavior are studied combined with MD Simulation. Simulation results show that the saturates phase, in contrast to the naphthene aromatics phase, plays a major role in bitumen micro-mechanical behavior. A high stress zone occurs at the interface between the saturates phase and the naphthene aromatics phase, which may form discontinuities that further affect the bitumen frictional performance.

Characterization of Bitumen Micro-Mechanical Behaviors Using AFM, Phase Dynamics Theory and MD Simulation.

Science.gov (United States)

Hou, Yue; Wang, Linbing; Wang, Dawei; Guo, Meng; Liu, Pengfei; Yu, Jianxin

2017-02-21

Fundamental understanding of micro-mechanical behaviors in bitumen, including phase separation, micro-friction, micro-abrasion, etc., can help the pavement engineers better understand the bitumen mechanical performances at macroscale. Recent researches show that the microstructure evolution in bitumen will directly affect its surface structure and micro-mechanical performance. In this study, the bitumen microstructure and micro-mechanical behaviors are studied using Atomic Force Microscopy (AFM) experiments, Phase Dynamics Theory and Molecular Dynamics (MD) Simulation. The AFM experiment results show that different phase-structure will occur at the surface of the bitumen samples under certain thermodynamic conditions at microscale. The phenomenon can be explained using the phase dynamics theory, where the effects of stability parameter and temperature on bitumen microstructure and micro-mechanical behavior are studied combined with MD Simulation. Simulation results show that the saturates phase, in contrast to the naphthene aromatics phase, plays a major role in bitumen micro-mechanical behavior. A high stress zone occurs at the interface between the saturates phase and the naphthene aromatics phase, which may form discontinuities that further affect the bitumen frictional performance.

Kinematics and dynamics analysis of a quadruped walking robot with parallel leg mechanism

Science.gov (United States)

Wang, Hongbo; Sang, Lingfeng; Hu, Xing; Zhang, Dianfan; Yu, Hongnian

2013-09-01

It is desired to require a walking robot for the elderly and the disabled to have large capacity, high stiffness, stability, etc. However, the existing walking robots cannot achieve these requirements because of the weight-payload ratio and simple function. Therefore, Improvement of enhancing capacity and functions of the walking robot is an important research issue. According to walking requirements and combining modularization and reconfigurable ideas, a quadruped/biped reconfigurable walking robot with parallel leg mechanism is proposed. The proposed robot can be used for both a biped and a quadruped walking robot. The kinematics and performance analysis of a 3-UPU parallel mechanism which is the basic leg mechanism of a quadruped walking robot are conducted and the structural parameters are optimized. The results show that performance of the walking robot is optimal when the circumradius R, r of the upper and lower platform of leg mechanism are 161.7 mm, 57.7 mm, respectively. Based on the optimal results, the kinematics and dynamics of the quadruped walking robot in the static walking mode are derived with the application of parallel mechanism and influence coefficient theory, and the optimal coordination distribution of the dynamic load for the quadruped walking robot with over-determinate inputs is analyzed, which solves dynamic load coupling caused by the branches’ constraint of the robot in the walk process. Besides laying a theoretical foundation for development of the prototype, the kinematics and dynamics studies on the quadruped walking robot also boost the theoretical research of the quadruped walking and the practical applications of parallel mechanism.

Governing the Nexus for Sustainability

Directory of Open Access Journals (Sweden)

Marx Sina

2015-01-01

Full Text Available This report summarizes the challenges of and requirements for effective governance of the water, energy and food nexus. With global dynamics such as climate change, urbanization and changing consumption patterns, governing resources in a coherent manner becomes both more complex and more relevant for sustainable development. Governance challenges include nexus economics (costs and benefits of different approaches to resource management, institutional design (like questions of how decision-making should be best distributed and good governance (how to make sure that nexus governance adheres to certain agreed upon principles and values. In terms of economics, a balance between sector specific actions and nexus governance is required. For effective decision-making it is important that power among different institutions is both distributed and coordinated. Good nexus governance requires targets that can be monitored to make sure that basic principles are followed and to examine whether progress toward sustainable development is being made.

Molecular Dynamics Simulations with Quantum Mechanics/Molecular Mechanics and Adaptive Neural Networks.

Science.gov (United States)

Shen, Lin; Yang, Weitao

2018-03-13

Direct molecular dynamics (MD) simulation with ab initio quantum mechanical and molecular mechanical (QM/MM) methods is very powerful for studying the mechanism of chemical reactions in a complex environment but also very time-consuming. The computational cost of QM/MM calculations during MD simulations can be reduced significantly using semiempirical QM/MM methods with lower accuracy. To achieve higher accuracy at the ab initio QM/MM level, a correction on the existing semiempirical QM/MM model is an attractive idea. Recently, we reported a neural network (NN) method as QM/MM-NN to predict the potential energy difference between semiempirical and ab initio QM/MM approaches. The high-level results can be obtained using neural network based on semiempirical QM/MM MD simulations, but the lack of direct MD samplings at the ab initio QM/MM level is still a deficiency that limits the applications of QM/MM-NN. In the present paper, we developed a dynamic scheme of QM/MM-NN for direct MD simulations on the NN-predicted potential energy surface to approximate ab initio QM/MM MD. Since some configurations excluded from the database for NN training were encountered during simulations, which may cause some difficulties on MD samplings, an adaptive procedure inspired by the selection scheme reported by Behler [ Behler Int. J. Quantum Chem. 2015 , 115 , 1032 ; Behler Angew. Chem., Int. Ed. 2017 , 56 , 12828 ] was employed with some adaptions to update NN and carry out MD iteratively. We further applied the adaptive QM/MM-NN MD method to the free energy calculation and transition path optimization on chemical reactions in water. The results at the ab initio QM/MM level can be well reproduced using this method after 2-4 iteration cycles. The saving in computational cost is about 2 orders of magnitude. It demonstrates that the QM/MM-NN with direct MD simulations has great potentials not only for the calculation of thermodynamic properties but also for the characterization of

Flavor cosmology. Dynamical Yukawas in the Froggatt-Nielsen mechanism

Energy Technology Data Exchange (ETDEWEB)

Baldes, Iason; Konstandin, Thomas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Servant, Geraldine [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2016-12-02

Can the cosmological dynamics responsible for settling down the present values of the Cabibbo-Kobayashi-Maskawa matrix be related to electroweak symmetry breaking? If the Standard Model Yukawa couplings varied in the early universe and started with order one values before electroweak symmetry breaking, the CP violation associated with the CKM matrix could be the origin of the matter-antimatter asymmetry. The large effective Yukawa couplings which lead to the enhanced CP violation can also help in achieving a strong first-order electroweak phase transition. We study in detail the feasibility of this idea by implementing dynamical Yukawa couplings in the context of the Froggatt-Nielsen mechanism. We discuss two main realizations of such a mechanism, related phenomenology, cosmological and collider bounds, and provide an estimate of the baryonic yield. A generic prediction is that this scenario always features a new scalar field below the electroweak scale. We point out ways to get around this conclusion.

Flavor cosmology: dynamical yukawas in the Froggatt-Nielsen mechanism

Energy Technology Data Exchange (ETDEWEB)

Baldes, Iason; Konstandin, Thomas [DESY,Notkestraße 85, Hamburg, D-22607 (Germany); Servant, Géraldine [DESY,Notkestraße 85, Hamburg, D-22607 (Germany); II. Institute for Theoretical Physics, University of Hamburg,Luruper Chaussee 149, Hamburg, D-22761 (Germany)

2016-12-15

Can the cosmological dynamics responsible for settling down the present values of the Cabibbo-Kobayashi-Maskawa matrix be related to electroweak symmetry breaking? If the Standard Model Yukawa couplings varied in the early universe and started with order one values before electroweak symmetry breaking, the CP violation associated with the CKM matrix could be the origin of the matter-antimatter asymmetry. The large effective Yukawa couplings which lead to the enhanced CP violation can also help in achieving a strong first-order electroweak phase transition. We study in detail the feasibility of this idea by implementing dynamical Yukawa couplings in the context of the Froggatt-Nielsen mechanism. We discuss two main realizations of such a mechanism, related phenomenology, cosmological and collider bounds, and provide an estimate of the baryonic yield. A generic prediction is that this scenario always features a new scalar field below the electroweak scale. We point out ways to get around this conclusion.

Linking Governance to Sustainable Management Outcomes: Applying Dynamic Indicator Profiles to River Basin Organization Case Studies around the World.

Science.gov (United States)

Wei, Y.; Bouckaert, F. W.

2017-12-01

Institutional best practice for integrated river basin management advocates the river basin organisation (RBO) model as pivotal to achieve sustainable management outcomes and stakeholder engagement. The model has been widely practiced in transboundary settings and is increasingly adopted at national scales, though its effectiveness remains poorly studied. A meta-analysis of four river basins has been conducted to assess governance models and linking it to evaluation of biophysical management outcomes. The analysis is based on a Theory of Change framework, and includes functional dynamic governance indicator profiles, coupled to sustainable ecosystem management outcome profiles. The governance and outcome profiles, informed by context specific indicators, demand that targets for setting objectives are required in multiple dimensions, and trajectory outlines are a useful tool to track progress along the journey mapped out by the Theory of Change framework. Priorities, trade-offs and objectives vary in each basin, but the diagnostics tool allows comparison between basins in their capacity to reach targets through successive evaluations. The distance between capacity and target scores determines how program planning should be prioritized and resources allocated for implementation; this is a dynamic process requiring regular evaluations and adaptive management. The findings of this study provide a conceptual framework for combining dimensions of integrated water management principles that bridge tensions between (i) stakeholder engagement and participatory management (bottom-up approach) using localized knowledge and (ii) decision-making, control-and-command, system-scale, accountable and equitable management (top-down approach).The notion of adaptive management is broadened to include whole-of-program learnings, rather than single hypothesis based learning adjustments. This triple loop learning combines exploitative methods refinement with explorative evaluation of

Injurious mechanical ventilation in the normal lung causes a progressive pathologic change in dynamic alveolar mechanics

OpenAIRE

Pavone, Lucio A; Albert, Scott; Carney, David; Gatto, Louis A; Halter, Jeffrey M; Nieman, Gary F

2007-01-01

Introduction Acute respiratory distress syndrome causes a heterogeneous lung injury, and without protective mechanical ventilation a secondary ventilator-induced lung injury can occur. To ventilate noncompliant lung regions, high inflation pressures are required to 'pop open' the injured alveoli. The temporal impact, however, of these elevated pressures on normal alveolar mechanics (that is, the dynamic change in alveolar size and shape during ventilation) is unknown. In the present study we ...

China's Insurance Regulatory Reform, Corporate Governance Behavior and Insurers' Governance Effectiveness.

Science.gov (United States)

Li, Huicong; Zhang, Hongliang; Tsai, Sang-Bing; Qiu, Aichao

2017-10-17

External regulation is an important mechanism to improve corporate behavior in emerging markets. China's insurance governance regulation, which began to supervise and guide insurance corporate governance behavior in 2006, has experienced a complex process of reform. This study tested our hypotheses with a sample of 85 firms during 2010-2011, which was obtained by providing a questionnaire to all of China's shareholding insurance companies. The empirical study results generally show that China's insurance governance effectiveness has significantly improved through strict regulation. Insurance corporate governance can improve business acumen and risk-control ability, but no significant evidence was found to prove its influence on profitability, as a result of focusing less attention on governance than on management. State ownership is associated with higher corporate governance effectiveness than non-state ownership. Listed companies tend to outperform non-listed firms, and life insurance corporate governance is more effective than that of property insurers. This study not only contributes to the comprehensive understanding of corporate governance effectiveness but also to the literature by highlighting the effect of corporate governance regulation in China's insurance industry and other emerging economies of the financial sector.

Dynamic Mechanical and Thermal Properties of Bagasse/Glass Fiber/Polypropylene Hybrid Composites

Directory of Open Access Journals (Sweden)

Mehdi Roohani

2016-06-01

Full Text Available This work aims to evaluate the thermal and dynamic mechanical properties of bagasse/glass fiber/polypropylene hybrid composites. Composites were prepared by the melt compounding method and their properties were characterized by differential scanning calorimetry (DSC and dynamic mechanical analysis (DMA. DSC results found that with incorporation of bagasse and glass fiber the melting temperature (Tm and the crystallisation temperature (Tc shift to higher temperatures and the degree of crystallinity (Xc increase. These findings suggest that the fibers played the role of a nucleating agent in composites. Dynamic mechanical analysis indicated that by the incorporation of bagasse and glass fiber into polypropylene, the storage modulus ( and the loss modulus ( increase whereas the mechanical loss factor (tanδ decrease. To assess the effect of reinforcement with increasing temperature, the effectiveness coefficient C was calculated at different temperature ranges and revealed that, at the elevated temperatures, improvement of mechanical properties due to the presence of fibers was more noticeable. The fiber-matrix adhesion efficiency determined by calculating of adhesion factor A in terms of the relative damping of the composite (tan δc and the polymer (tan δpand volume fraction of the fibers (Фf. Calculated adhesion factor A values indicated that by adding glass fiber to bagasse/polypropylene system, the fiber-matrix adhesion improve. Hybrid composite containing 25% bagasse and 15% glass fiber showed better fiber-matrix adhesion.

A Dynamic Market Mechanism for Markets with Shiftable Demand Response

DEFF Research Database (Denmark)

Hansen, Jacob; Knudsen, Jesper Viese; Kiani, Arman

2014-01-01

renewables, this mechanism accommodates both consumers with a shiftable Demand Response and an adjustable Demand Response. The overall market mechanism is evaluated in a Day Ahead Market and is shown in a numerical example to result in a reduction of the cost of electricity for the consumer, as well......In this paper, we propose a dynamic market mechanism that converges to the desired market equilibrium. Both locational marginal prices and the schedules for generation and consumption are determined through a negotiation process between the key market players. In addition to incorporating...

Geometry and topology in hamiltonian dynamics and statistical mechanics

CERN Document Server

Pettini, Marco

2007-01-01

Explores the foundations of hamiltonian dynamical systems and statistical mechanics, in particular phase transitions, from the point of view of geometry and topology. This book provides an overview of the research in the area. Using geometrical thinking to solve fundamental problems in these areas could be highly productive

Energy Efficiency Governance: Handbook

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

This handbook has been written to assist EE practitioners, government officials and stakeholders to establish effective EE governance structures for their country. The handbook provides readers with relevant information in an accessible format that will help develop comprehensive and effective governance mechanisms. For each of the specific topics dealt with (see Figure 1 in the Handbook), the IEA offers guidelines for addressing issues, or directs readers to examples of how such issues have been dealt with by specific countries.

Influence of surface wettability on transport mechanisms governing water droplet evaporation.

Science.gov (United States)

Pan, Zhenhai; Weibel, Justin A; Garimella, Suresh V

2014-08-19

Prediction and manipulation of the evaporation of small droplets is a fundamental problem with importance in a variety of microfluidic, microfabrication, and biomedical applications. A vapor-diffusion-based model has been widely employed to predict the interfacial evaporation rate; however, its scope of applicability is limited due to incorporation of a number of simplifying assumptions of the physical behavior. Two key transport mechanisms besides vapor diffusion-evaporative cooling and natural convection in the surrounding gas-are investigated here as a function of the substrate wettability using an augmented droplet evaporation model. Three regimes are distinguished by the instantaneous contact angle (CA). In Regime I (CA ≲ 60°), the flat droplet shape results in a small thermal resistance between the liquid-vapor interface and substrate, which mitigates the effect of evaporative cooling; upward gas-phase natural convection enhances evaporation. In Regime II (60 ≲ CA ≲ 90°), evaporative cooling at the interface suppresses evaporation with increasing contact angle and counterbalances the gas-phase convection enhancement. Because effects of the evaporative cooling and gas-phase convection mechanisms largely neutralize each other, the vapor-diffusion-based model can predict the overall evaporation rates in this regime. In Regime III (CA ≳ 90°), evaporative cooling suppresses the evaporation rate significantly and reverses entirely the direction of natural convection induced by vapor concentration gradients in the gas phase. Delineation of these counteracting mechanisms reconciles previous debate (founded on single-surface experiments or models that consider only a subset of the governing transport mechanisms) regarding the applicability of the classic vapor-diffusion model. The vapor diffusion-based model cannot predict the local evaporation flux along the interface for high contact angle (CA ≥ 90°) when evaporative cooling is strong and the

Dynamics of technology shifts in the household sector-implications for clean development mechanism

International Nuclear Information System (INIS)

Reddy, B. Sudhakara; Balachandra, P.

2006-01-01

The present paper attempts to analyse the dynamics of energy end-use technology shifts in the household sector in India. The technology shifts can be categorized as naturally occurring shifts (with increasing household incomes and availability of energy carriers) and policy-induced shifts (by creating a favourable environment). Initially, the households energy usage patterns, types of energy carriers and the technologies in use are analysed using the data from the National Sample Survey (1999-2000). The energy consumption is disaggregated according to end-use activity and by income groups for rural as well as urban households. It is observed that large variations in energy use exist across different sections of households-urban/rural, low/high-income groups, etc. Further, the paper provides a methodological framework for the diffusion of energy-efficient technologies, and the implications of such diffusions for the Clean Development Mechanism (CDM). It analyses the reasons for the gap between possible and practical implementation of energy-efficient measures, study the reasons for households not using the cost-effective technologies available to them, the benefits of innovation of energy efficiency, and the required policies and specific proposals for government intervention to achieve the potential for the CDM

'Governance' sebagai Pengelolaan Konflik

Directory of Open Access Journals (Sweden)

Riza Noer Arfani

2005-03-01

Full Text Available The article explores the notion of understanding governance as part of conflict management, or vice versa, of undustanding conflict management aspects as benefiting from governance concepts and practices. Governance, with its much broader meaning than government, suggests diverse relevant and significant clues, hints and ideas in the context of conflict management endeavors. one of which is the idea to involve larger audiences and stakeholders –beyond the conventional institutions such as governmental bodies– in policy making processes and public discourses. Such comprehension and appreciation of governance concepts and practices is certainly parallel with the conflict management philosophies, concepis and practices which based on and oriented toward integrative, non-formal and non-litigative mechanisms.

Dynamical phase transitions in quantum mechanics

International Nuclear Information System (INIS)

Rotter, Ingrid

2012-01-01

1936 Niels Bohr: In the atom and in the nucleus we have indeed to do with two extreme cases of mechanical many-body problems for which a procedure of approximation resting on a combination of one-body problems, so effective in the former case, loses any validity in the latter where we, from the very beginning, have to do with essential collective aspects of the interplay between the constituent particles. 1963: Maria Goeppert-Mayer and J. Hans D. Jensen received the Nobel Prize in Physics for their discoveries concerning nuclear shell structure. State of the art 2011: - The nucleus is an open quantum system described by a non-Hermitian Hamilton operator with complex eigenvalues. The eigenvalues may cross in the complex plane ('exceptional points'), the phases of the eigenfunctions are not rigid in approaching the crossing points and the widths bifurcate. By this, a dynamical phase transition occurs in the many-level system. The dynamical phase transition starts at a critical value of the level density. Hence the properties of he low-lying nuclear states (described well by the shell model) and those of highly excited nuclear states (described by random ensembles) differ fundamentally from one another. The statement of Niels Bohr for compound nucleus states at high level density is not in contradiction to the shell-model description of nuclear (and atomic) states at low level density. Dynamical phase transitions are observed experimentally in different systems, including PT-symmetric ones, by varying one or more parameters

Emergence of the second law out of reversible dynamics

NARCIS (Netherlands)

Willigenburg, van L.G.; Koning, de W.L.

2009-01-01

Abstract If one demystifies entropy the second law of thermodynamics comes out as an emergent property entirely based on the simple dynamic mechanical laws that govern the motion and energies of system parts on a micro-scale. The emergence of the second law is illustrated in this paper through the

Information governance in dynamic networked business process management

NARCIS (Netherlands)

Rasouli, M.; Eshuis, H.; Grefen, P.W.P.J.; Trienekens, J.J.M.; Kusters, R.J.

2016-01-01

Competition in today’s globalized markets forces organizations to collaborate within dynamic business networks to provide mass-customized integrated solutions for customers. The collaboration within dynamic business networks necessitates forming dynamic networked business processes (DNBPs).

Self-Sustaining Dynamical Nuclear Polarization Oscillations in Quantum Dots

DEFF Research Database (Denmark)

Rudner, Mark Spencer; Levitov, Leonid

2013-01-01

Early experiments on spin-blockaded double quantum dots revealed robust, large-amplitude current oscillations in the presence of a static (dc) source-drain bias. Despite experimental evidence implicating dynamical nuclear polarization, the mechanism has remained a mystery. Here we introduce......) and nuclear spin diffusion, which governs dynamics of the spatial profile of nuclear polarization. The proposed framework naturally explains the differences in phenomenology between vertical and lateral quantum dot structures as well as the extremely long oscillation periods....

Molecular Mechanisms That Underlie the Dynamic Adaptation of Innate Monocyte Memory to Varying Stimulant Strength of TLR Ligands.

Science.gov (United States)

Yuan, Ruoxi; Geng, Shuo; Li, Liwu

2016-01-01

In adaptation to rising stimulant strength, innate monocytes can be dynamically programed to preferentially express either pro- or anti-inflammatory mediators. Such dynamic innate adaptation or programing may bear profound relevance in host health and disease. However, molecular mechanisms that govern innate adaptation to varying strength of stimulants are not well understood. Using lipopolysaccharide (LPS), the model stimulant of toll-like-receptor 4 (TLR4), we reported that the expressions of pro-inflammatory mediators are preferentially sustained in monocytes adapted by lower doses of LPS, and suppressed/tolerized in monocytes adapted by higher doses of LPS. Mechanistically, monocytes adapted by super-low dose LPS exhibited higher levels of transcription factor, interferon regulatory factor 5 (IRF5), and reduced levels of transcriptional modulator B lymphocyte-induced maturation protein-1 (Blimp-1). Intriguingly, the inflammatory monocyte adaptation by super-low dose LPS is dependent upon TRAM/TRIF but not MyD88. Similar to LPS, we also observed biphasic inflammatory adaptation and tolerance in monocytes challenged with varying dosages of TLR7 agonist. In sharp contrast, rising doses of TLR3 agonist preferentially caused inflammatory adaptation without inducing tolerance. At the molecular level, the differential regulation of IRF5 and Blimp-1 coincides with unique monocyte adaptation dynamics by TLR4/7 and TLR3 agonists. Our study provides novel clue toward the understanding of monocyte adaptation and memory toward distinct TLR ligands.

Molecular mechanisms that underlie the dynamic adaptation of innate monocyte memory to varying stimulant strength of TLR ligands

Directory of Open Access Journals (Sweden)

Ruoxi Yuan

2016-11-01

Full Text Available In adaptation to rising stimulant strength, innate monocytes can be dynamically programmed to preferentially express either pro- or anti-inflammatory mediators. Such dynamic innate adaptation or programming may bear profound relevance in host health and disease. However, molecular mechanisms that govern innate adaptation to varying strength of stimulants are not well understood. Using lipopolysaccharide (LPS, the model stimulant of Toll-Like-Receptor 4 (TLR4, we reported that the expressions of pro-inflammatory mediators are preferentially sustained in monocytes adapted by lower doses of LPS, and suppressed/tolerized in monocytes adapted by higher doses of LPS. Mechanistically, monocytes adapted by super-low dose LPS exhibited higher levels of transcription factor IRF5 and reduced levels of transcriptional modulator BLIMP-1. Intriguingly, the inflammatory monocyte adaptation by super-low dose LPS is dependent upon TRAM/TRIF but not MyD88. Similar to LPS, we also observed biphasic inflammatory adaptation and tolerance in monocytes challenged with varying dosages of TLR7 agonist. In sharp contrast, rising doses of TLR3 agonist preferentially caused inflammatory adaptation without inducing tolerance. At the molecular level, the differential regulation of IRF5 and Blimp-1 coincides with unique monocyte adaptation dynamics by TLR4/7 and TLR3 agonists. Our study provides novel clue toward the understanding of monocyte adaptation and memory toward distinct TLR ligands.

On a possible mechanism of the brain for responding to dynamical features extracted from input signals

International Nuclear Information System (INIS)

Liu Zengrong; Chen Guanrong

2003-01-01

Based on the general theory of nonlinear dynamical systems, a possible mechanism for responding to some dynamical features extracted from input signals in brain activities is described and discussed. This mechanism is first converted to a nonlinear dynamical configuration--a generalized synchronization of complex dynamical systems. Then, some general conditions for achieving such synchronizations are derived. It is shown that dynamical systems have potentials of producing different responses for different features extracted from various input signals, which may be used to describe brain activities. For illustration, some numerical examples are given with simulation figures

Stochastic dynamics of penetrable rods in one dimension: Entangled dynamics and transport properties

Energy Technology Data Exchange (ETDEWEB)

Craven, Galen T.; Popov, Alexander V.; Hernandez, Rigoberto, E-mail: hernandez@chemistry.gatech.edu [Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400 (United States)

2015-04-21

The dynamical properties of a system of soft rods governed by stochastic hard collisions (SHCs) have been determined over a varying range of softness using molecular dynamics simulations in one dimension and analytic theory. The SHC model allows for interpenetration of the system’s constituent particles in the simulations, generating overlapping clustering behavior analogous to the spatial structures observed in systems governed by deterministic bounded potentials. Through variation of an assigned softness parameter δ, the limiting ranges of intermolecular softness are bridged, connecting the limiting ensemble behavior from hard to ideal (completely soft). Various dynamical and structural observables are measured from simulation and compared to developed theoretical values. The spatial properties are found to be well predicted by theories developed for the deterministic penetrable-sphere model with a transformation from energetic to probabilistic arguments. While the overlapping spatial structures are complex, the dynamical properties can be adequately approximated through a theory built on impulsive interactions with Enskog corrections. Our theory suggests that as the softness of interaction is varied toward the ideal limit, correlated collision processes are less important to the energy transfer mechanism, and Markovian processes dominate the evolution of the configuration space ensemble. For interaction softness close to hard limit, collision processes are highly correlated and overlapping spatial configurations give rise to entanglement of single-particle trajectories.

Dynamic compressive properties and failure mechanism of glass fiber reinforced silica hydrogel

International Nuclear Information System (INIS)

Yang Jie; Li Shukui; Yan Lili; Huo Dongmei; Wang Fuchi

2010-01-01

The dynamic compressive properties of glass fiber reinforced silica (GFRS) hydrogel were investigated using a spilt Hopkinson pressure bar. Failure mechanism of GFRS hydrogel was studied by scanning electron microscopy (SEM). Result showed that dynamic compressive stresses were much higher than the quasi-static compressive stresses at the same strain. The dynamic compressive strength was directly proportional to the strain rate with same sample dimensions. The dynamic compressive strength was directly proportional to the sample basal area at same strain rate. Dynamic compressive failure strain was small. At high strain rates, glass fibers broke down and separated from the matrix, pores shrank rapidly. Failure resulted from the increase of lateral tensile stress in hydrogel under dynamic compression.

Dynamics of tunneling ionization using Bohmian mechanics

Science.gov (United States)

Douguet, Nicolas; Bartschat, Klaus

2018-01-01

Recent attoclock experiments and theoretical studies regarding the strong-field ionization of atoms by few-cycle infrared pulses revealed features that have attracted much attention. Here we investigate tunneling ionization and the dynamics of the electron probability using Bohmian mechanics. We consider a one-dimensional problem to illustrate the underlying mechanisms of the ionization process. It is revealed that in the major part of the below-the-barrier ionization regime, in an intense and short infrared pulse, the electron does not tunnel through the entire barrier, but rather starts already from the classically forbidden region. Moreover, we highlight the correspondence between the probability of locating the electron at a particular initial position and its asymptotic momentum. Bohmian mechanics also provides a natural definition of mean tunneling time and exit position, taking account of the time dependence of the barrier. Finally, we find that the electron can exit the barrier with significant kinetic energy, thereby corroborating the results of a recent study [N. Camus et al., Phys. Rev. Lett. 119, 023201 (2017), 10.1103/PhysRevLett.119.023201].

Governing IT outsourcing relationships

CERN Document Server

Kuhlmann, Daniel

2012-01-01

Hauptbeschreibung The dynamics of the relationship between service recipient and service provider in IS outsourcing relationships recently gained increased attention as relationships are believed to have a considerable influence on IS outsourcing success. This study adds to this growing field of interest by developing an IS outsourcing relationship framework in the form of a process model. Three rather disjointed areas of research, namely contractual governance, relational norms, and control, have been set in a common context by interrelating them as the three main governance modes

Spinorial space-time and the origin of Quantum Mechanics. The dynamical role of the physical vacuum

International Nuclear Information System (INIS)

Gonzalez-Mestres, Luis

2016-01-01

nonzero values simultaneously in a whole time interval. Then, continuous motion can be precluded at very small spacetime scales. If discrete motion is required at such scales, the situation will possibly be close to that generating the Feynman path integral. More generally, Quantum Mechanics can naturally emerge from the spinorial space-time and from other unconventional spacetime structures in a fundamental preon dynamics governing the properties of vacuum. In such scenarios, the application of Gödel - Cohen mathematics to quantum-mechanical calculations can possibly yield substantially different results from those recently obtained using the standard quantum approach without any preonic underlying structure. This is also a crucial open question for Quantum Mechanics and Particle Physics. This paper is dedicated to the memory of Bernard d’Espagnat

Comprehensive Study on Thermal and Dynamic Mechanical Behavior of PET/PEN Blends

Directory of Open Access Journals (Sweden)

Hossien Ali Khonakdar

2013-10-01

Full Text Available The effects of interchange reactions on the crystallization, melting, and dynamic mechanical thermal behavior of poly(ethylene terephthalate/poly(ethylene naphthalate (PET/PEN blends prepared by melt mixing have been investigated. The occurrence of interchange reactions has been verified by proton nuclear magnetic resonance (1H NMR. Differential scanning calorimetry (DSC and dynamic mechanical analysis (DMA were used to study the effect of transesterification reaction on crystallinity, melting and dynamic mechanical properties of the blends. It was found that by extension of transesterification, the miscibility of the blend increased. Time and temperature of mixing were most important parameters affecting the transesterification level. On blending, the melt crystallinity of poly(ethylene terephthalate was reduced and in contrast that of poly(ethylene naphthalate was increased; where melt crystallization temperatures of both phases were depressed. A single composition-dependent glass transition peak, which was indicative of miscibility, was detected in second heating thermograms of the blends. It was observed that cold crystallization of poly(ethylene terephthalate phase decreases while that of poly(ethylene naphthalate was suppressed on blending. It was found that each phase crystallized individually and a melting point depression which was an indication of compatibility was evident at the same time. Dynamic mechanical analysis confirmed the proton nuclear magnetic resonance and differential scanning calorimetry results. The secondary viscoelastic transitions of each phase in blend samples were also probed. Increment of peak area in the loss factor has implied the miscibility of blend due to formation of poly(ethylene terephthalate/poly(ethylene naphthalate random copolymer.

Institutional change and corporate governance reform

Directory of Open Access Journals (Sweden)

Harilaos Mertzanis

2011-04-01

Full Text Available The global financial crisis has posed challenges to financial institutions governance. Meeting these challenges requires an understanding of governance dynamics in relation to institutions’ performance within a changing environment. The nature and scope of institutional response to a changing environment depends upon inherited governance structures, including socioeconomic conventions and rules of behavior at the macro level and time, expertise and common commitment of directors at the micro level. Innovation and learning-by-doing in governance can be an effective reform strategy. Innovation in governance may include the establishment of new norms of economic behavior and the transformation of decision-making process and the reallocation of responsibilities to directors and senior management. This may also inform regulatory approaches in strengthening financial institutions governance, based on improved disclosure, independent and competent boards

A dynamic allocation mechanism of delivering capacity in coupled networks

International Nuclear Information System (INIS)

Du, Wen-Bo; Zhou, Xing-Lian; Zhu, Yan-Bo; Zheng, Zheng

2015-01-01

Traffic process is ubiquitous in many critical infrastructures. In this paper, we introduce a mechanism to dynamically allocate the delivering capacity into the data-packet traffic model on the coupled Internet autonomous-system-level network of South Korea and Japan, and focus on its effect on the transport efficiency. In this mechanism, the total delivering capacity is constant and the lowest-load node will give one unit delivering capacity to the highest-load node at each time step. It is found that the delivering capacity of busy nodes and non-busy nodes can be well balanced and the effective betweenness of busy nodes with interconnections is significantly reduced. Consequently, the transport efficiency such as average traveling time and packet arrival rate is remarkably improved. Our work may shed some light on the traffic dynamics in coupled networks.

Implikasi Corporate Governance terhadap Kinerja Family Business di Indonesia

Directory of Open Access Journals (Sweden)

Iskandar Itan

2017-02-01

Full Text Available Penelitian ini melihat hubungan antara corporate governance quality dan kinerja pada perusahaan keluarga di Indonesia. Penelitian ini dilakukan pada 126 perusahaan yang terdaftar di Bursa Efek Indonesia untuk periode 2008 sampai 2012 dengan menggunakan analisis regresi berganda. Dalam penelitian ini, corporate governance quality di proksikan dengan corporate governance process dan corporate governance mechanism, sedangkan kinerja perusahaan diukur dengan ROA dan Tobin’s Q. Corporate governace process terdiri dari variabel hak-hak pemegang saham, perlakuan yang adil terhadap pemegang saham, peran pemangku kepentingan, pengungkapan dan transparansi, dan tanggung jawab dewan. Sedangkan variabel corporate governance mechanism adalah ukuran dewan direksi, komisaris independen, kepemilikan manajerial, dan kepemilikan asing. Hasil analisis menunjukkan bahwa variabel hak-hak pemegang saham, perlakuan yang adil terhadap pemegang saham, ukuran dewan direksi, kepemilikan manajerial, dan kepemilikan asing mempunyai pengaruh signifikan terhadap kinerja perusahaan yang diukur dengan ROA. Sementara itu, variabel pengungkapan dan transparansi, tanggung jawab dewan, dan ukuran dewan direksi berpengaruh terhadap Tobin’s Q.Kata kunci:  Mekanisme corporate governance; corporate governance process kinerja perusahaanThis paper explores the relationship between corporate governance quality and firm performance of family business in Indonesia. This study covers the period of 2008 to 2012 and 126 listed family companies from Indonesia Stock Exchange are included has been examined by using multiple regression analysis. In this study, corporate governance quality is proxied by corporate governance process and corporate governance mechanism, while performance is measured by return on assets (ROA and Tobin‘s Q. Measures of corporate governance process employed are rights of shareholders, equitable treatment of shareholders, role of stakeholders, disclosure and

A dynamical approach toward understanding mechanisms of team science: change, kinship, tension, and heritage in a transdisciplinary team.

Science.gov (United States)

Lotrecchiano, Gaetano R

2013-08-01

Since the concept of team science gained recognition among biomedical researchers, social scientists have been challenged with investigating evidence of team mechanisms and functional dynamics within transdisciplinary teams. Identification of these mechanisms has lacked substantial research using grounded theory models to adequately describe their dynamical qualities. Research trends continue to favor the measurement of teams by isolating occurrences of production over relational mechanistic team tendencies. This study uses a social constructionist-grounded multilevel mixed methods approach to identify social dynamics and mechanisms within a transdisciplinary team. A National Institutes of Health-funded research team served as a sample. Data from observations, interviews, and focus groups were qualitatively coded to generate micro/meso level analyses. Social mechanisms operative within this biomedical scientific team were identified. Dynamics that support such mechanisms were documented and explored. Through theoretical and emergent coding, four social mechanisms dominated in the analysis-change, kinship, tension, and heritage. Each contains relational social dynamics. This micro/meso level study suggests such mechanisms and dynamics are key features of team science and as such can inform problems of integration, praxis, and engagement in teams. © 2013 Wiley Periodicals, Inc.

Dynamics and mechanisms of chemotherapy-induced ovarian follicular depletion in women of fertile age

DEFF Research Database (Denmark)

Rosendahl, Mikkel; Andersen, Claus Yding; la Cour Freiesleben, Nina

2010-01-01

To study ovarian follicular dynamics during chemotherapy to understand the mechanisms behind chemotherapy-induced ovarian follicular depletion and to evaluate whether pretreatment levels of ovarian reserve markers were predictive of the posttreatment levels.......To study ovarian follicular dynamics during chemotherapy to understand the mechanisms behind chemotherapy-induced ovarian follicular depletion and to evaluate whether pretreatment levels of ovarian reserve markers were predictive of the posttreatment levels....

Chemical dynamics in the gas phase: Time-dependent quantum mechanics of chemical reactions

Energy Technology Data Exchange (ETDEWEB)

Gray, S.K. [Argonne National Laboratory, IL (United States)

1993-12-01

A major goal of this research is to obtain an understanding of the molecular reaction dynamics of three and four atom chemical reactions using numerically accurate quantum dynamics. This work involves: (i) the development and/or improvement of accurate quantum mechanical methods for the calculation and analysis of the properties of chemical reactions (e.g., rate constants and product distributions), and (ii) the determination of accurate dynamical results for selected chemical systems, which allow one to compare directly with experiment, determine the reliability of the underlying potential energy surfaces, and test the validity of approximate theories. This research emphasizes the use of recently developed time-dependent quantum mechanical methods, i.e. wave packet methods.

Poverty, governance and economic growth

Directory of Open Access Journals (Sweden)

Kefi Mohamed Karim

2013-07-01

Full Text Available The objective of this paper is to study the effect of governance and povrety on economic growth of a set of eight developing countries during the period 2000-2009, using a dynamic and static panel data model and a simultaneous equations model. The key findings generated from these three empirical tests stipulate a negative effect of governance on povrety and a positive effect of political instability and corruption on poverty

Study on the dynamic recrystallization model and mechanism of nuclear grade 316LN austenitic stainless steel

International Nuclear Information System (INIS)

Wang, Shenglong; Zhang, Mingxian; Wu, Huanchun; Yang, Bin

2016-01-01

In this study, the dynamic recrystallization behaviors of a nuclear grade 316LN austenitic stainless steel were researched through hot compression experiment performed on a Gleeble-1500 simulator at temperatures of 900–1250 °C and strain rates of 0.01–1 s −1 . By multiple linear regressions of the flow stress-strain data, the dynamic recrystallization mathematical models of this steel as functions of strain rate, strain and temperature were developed. Then these models were verified in a real experiment. Furthermore, the dynamic recrystallization mechanism of the steel was determined. The results indicated that the subgrains in this steel are formed through dislocations polygonization and then grow up through subgrain boundaries migration towards high density dislocation areas and subgrain coalescence mechanism. Dynamic recrystallization nucleation performs in grain boundary bulging mechanism and subgrain growth mechanism. The nuclei grow up through high angle grain boundaries migration. - Highlights: •Establish the DRX mathematical models of nuclear grade 316LN stainless steel •Determine the DRX mechanism of this steel •Subgrains are formed through dislocations polygonization. •Subgrains grow up through subgrain boundaries migration and coalescence mechanism. •DRX nucleation performs in grain boundary bulging mechanism and subgrain growth mechanism.

The effect of governance mechanisms on food safety in the supply chain: Evidence from the Lebanese dairy sector.

Science.gov (United States)

Abebe, Gumataw K; Chalak, Ali; Abiad, Mohamad G

2017-07-01

Food safety is a key public health issue worldwide. This study aims to characterise existing governance mechanisms - governance structures (GSs) and food safety management systems (FSMSs) - and analyse the alignment thereof in detecting food safety hazards, based on empirical evidence from Lebanon. Firm-to-firm and public baseline are the dominant FSMSs applied in a large-scale, while chain-wide FSMSs are observed only in a small-scale. Most transactions involving farmers are relational and market-based in contrast to (large-scale) processors, which opt for hierarchical GSs. Large-scale processors use a combination of FSMSs and GSs to minimise food safety hazards albeit potential increase in coordination costs; this is an important feature of modern food supply chains. The econometric analysis reveals contract period, on-farm inspection and experience having significant effects in minimising food safety hazards. However, the potential to implement farm-level FSMS is influenced by formality of the contract, herd size, trading partner choice, and experience. Public baseline FSMSs appear effective in controlling food safety hazards; however, this may not be viable due to the scarcity of public resources. We suggest public policies to focus on long-lasting governance mechanisms by introducing incentive schemes and farm-level FSMSs by providing loans and education to farmers. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Evaluating the reliability of multi-body mechanisms: A method considering the uncertainties of dynamic performance

International Nuclear Information System (INIS)

Wu, Jianing; Yan, Shaoze; Zuo, Ming J.

2016-01-01

Mechanism reliability is defined as the ability of a certain mechanism to maintain output accuracy under specified conditions. Mechanism reliability is generally assessed by the classical direct probability method (DPM) derived from the first order second moment (FOSM) method. The DPM relies strongly on the analytical form of the dynamic solution so it is not applicable to multi-body mechanisms that have only numerical solutions. In this paper, an indirect probability model (IPM) is proposed for mechanism reliability evaluation of multi-body mechanisms. IPM combines the dynamic equation, degradation function and Kaplan–Meier estimator to evaluate mechanism reliability comprehensively. Furthermore, to reduce the amount of computation in practical applications, the IPM is simplified into the indirect probability step model (IPSM). A case study of a crank–slider mechanism with clearance is investigated. Results show that relative errors between the theoretical and experimental results of mechanism reliability are less than 5%, demonstrating the effectiveness of the proposed method. - Highlights: • An indirect probability model (IPM) is proposed for mechanism reliability evaluation. • The dynamic equation, degradation function and Kaplan–Meier estimator are used. • Then the simplified form of indirect probability model is proposed. • The experimental results agree well with the predicted results.

Governing development of regions- case of Slovakia

OpenAIRE

Rudolf Bauer; Jana Knezova; Andrej Steiner

2014-01-01

Dynamism of development and competiveness of regions, as spatially and administratively defined units, depend not only on their natural, economic, social, and territorial potential but also on quality of regional development governance. At the time of creation of the regional level of territorial management in Slovakia there was expected that by introducing this new governance level the regional governments would become strong players in the field of regional development policy and provide su...

A dynamic systems model of basic developmental mechanisms : Piaget, Vygotsky, and beyond

NARCIS (Netherlands)

van Geert, P

1998-01-01

A dynamic systems model is proposed on the basis of a general developmental mechanism adopted from the theories of J. Piaget and L. S. Vygotsky, more particularly a mechanism based on the concepts assimilation versus accommodation and actual development versus zone of proximal development. In the

Mechanical properties of dynamic diffusion bonded joints in a mild alloy steel

International Nuclear Information System (INIS)

Gomez de Salazar, J. M.; Urena, A.; Menendez, M.

2001-01-01

Mechanical properties in Dynamic Diffusion Bonded (DDB) in a A.S.T.M. 1045 steel (=.45%C) joints were studied. The thermomechanical cycle added to the process, favours both the initial deformation stage and probably the diffusion mechanisms which participate in bond formation. (Author) 11 refs

China’s Insurance Regulatory Reform, Corporate Governance Behavior and Insurers’ Governance Effectiveness

Science.gov (United States)

Zhang, Hongliang; Qiu, Aichao

2017-01-01

External regulation is an important mechanism to improve corporate behavior in emerging markets. China’s insurance governance regulation, which began to supervise and guide insurance corporate governance behavior in 2006, has experienced a complex process of reform. This study tested our hypotheses with a sample of 85 firms during 2010–2011, which was obtained by providing a questionnaire to all of China’s shareholding insurance companies. The empirical study results generally show that China’s insurance governance effectiveness has significantly improved through strict regulation. Insurance corporate governance can improve business acumen and risk-control ability, but no significant evidence was found to prove its influence on profitability, as a result of focusing less attention on governance than on management. State ownership is associated with higher corporate governance effectiveness than non-state ownership. Listed companies tend to outperform non-listed firms, and life insurance corporate governance is more effective than that of property insurers. This study not only contributes to the comprehensive understanding of corporate governance effectiveness but also to the literature by highlighting the effect of corporate governance regulation in China’s insurance industry and other emerging economies of the financial sector. PMID:29039781

China’s Insurance Regulatory Reform, Corporate Governance Behavior and Insurers’ Governance Effectiveness

Directory of Open Access Journals (Sweden)

Huicong Li

2017-10-01

Full Text Available External regulation is an important mechanism to improve corporate behavior in emerging markets. China’s insurance governance regulation, which began to supervise and guide insurance corporate governance behavior in 2006, has experienced a complex process of reform. This study tested our hypotheses with a sample of 85 firms during 2010–2011, which was obtained by providing a questionnaire to all of China’s shareholding insurance companies. The empirical study results generally show that China’s insurance governance effectiveness has significantly improved through strict regulation. Insurance corporate governance can improve business acumen and risk-control ability, but no significant evidence was found to prove its influence on profitability, as a result of focusing less attention on governance than on management. State ownership is associated with higher corporate governance effectiveness than non-state ownership. Listed companies tend to outperform non-listed firms, and life insurance corporate governance is more effective than that of property insurers. This study not only contributes to the comprehensive understanding of corporate governance effectiveness but also to the literature by highlighting the effect of corporate governance regulation in China’s insurance industry and other emerging economies of the financial sector.

Respiratory mechanics and fluid dynamics after lung resection surgery.

Science.gov (United States)

Miserocchi, Giuseppe; Beretta, Egidio; Rivolta, Ilaria

2010-08-01

Thoracic surgery that requires resection of a portion of lung or of a whole lung profoundly alters the mechanical and fluid dynamic setting of the lung-chest wall coupling, as well as the water balance in the pleural space and in the remaining lung. The most frequent postoperative complications are of a respiratory nature, and their incidence increases the more the preoperative respiratory condition seems compromised. There is an obvious need to identify risk factors concerning mainly the respiratory function, without neglecting the importance of other comorbidities, such as coronary disease. At present, however, a satisfactory predictor of postoperative cardiopulmonary complications is lacking; postoperative morbidity and mortality have remained unchanged in the last 10 years. The aim of this review is to provide a pathophysiologic interpretation of the main respiratory complications of a respiratory nature by relying on new concepts relating to lung fluid dynamics and mechanics. New parameters are proposed to improve evaluation of respiratory function from pre- to the early postoperative period when most of the complications occur. Published by Elsevier Inc.

Characterization of Thin Film Polymers Through Dynamic Mechanical Analysis and Permeation

Science.gov (United States)

Herring, Helen

2003-01-01

Thin polymer films are being considered, as candidate materials to augment the permeation resistance of cryogenic hydrogen fuel tanks such as would be required for future reusable launch vehicles. To evaluate performance of candidate films after environmental exposure, an experimental study was performed to measure the thermal/mechanical and permeation performance of six, commercial-grade materials. Dynamic storage modulus, as measured by Dynamic Mechanical Analysis, was found over a range of temperatures. Permeability, as measured by helium gas diffusion, was found at room temperature. Test data was correlated with respect to film type and pre-test exposure to moisture, elevated temperature, and cryogenic temperature. Results indicated that the six films were comparable in performance and their resistance to environmental degradation.

Fluid mechanics and heat transfer advances in nonlinear dynamics modeling

CERN Document Server

Asli, Kaveh Hariri

2015-01-01

This valuable new book focuses on new methods and techniques in fluid mechanics and heat transfer in mechanical engineering. The book includes the research of the authors on the development of optimal mathematical models and also uses modern computer technology and mathematical methods for the analysis of nonlinear dynamic processes. It covers technologies applicable to both fluid mechanics and heat transfer problems, which include a combination of physical, mechanical, and thermal techniques. The authors develop a new method for the calculation of mathematical models by computer technology, using parametric modeling techniques and multiple analyses for mechanical system. The information in this book is intended to help reduce the risk of system damage or failure. Included are sidebar discussions, which contain information and facts about each subject area that help to emphasize important points to remember.

The Independent and Shared Mechanisms of Intrinsic Brain Dynamics: Insights From Bistable Perception

Directory of Open Access Journals (Sweden)

Teng Cao

2018-04-01

Full Text Available In bistable perception, constant input leads to alternating perception. The dynamics of the changing perception reflects the intrinsic dynamic properties of the “unconscious inferential” process in the brain. Under the same condition, individuals differ in how fast they experience the perceptual alternation. In this study, testing many forms of bistable perception in a large number of observers, we investigated the key question of whether there is a general and common mechanism or multiple and independent mechanisms that control the dynamics of the inferential brain. Bistable phenomena tested include binocular rivalry, vase-face, Necker cube, moving plaid, motion induced blindness, biological motion, spinning dancer, rotating cylinder, Lissajous-figure, rolling wheel, and translating diamond. Switching dynamics for each bistable percept was measured in 100 observers. Results show that the switching rates of subsets of bistable percept are highly correlated. The clustering of dynamic properties of some bistable phenomena but not an overall general control of switching dynamics implies that the brain’s inferential processes are both shared and independent – faster in constructing 3D structure from motion does not mean faster in integrating components into an objects.

Social media & the Government: living happily ever after?

NARCIS (Netherlands)

Reint-Jan Renes; Danielle van Wallinga

2013-01-01

Social media play an important role in the rapidly changing dynamics of government organizations and their interaction with the public. Governments are facing changing demands at organizational level due to the exponential growth of connections, networks involved in social issues and collaboration

Mechanical Models of the Dynamics of Vitreous Substitutes

Directory of Open Access Journals (Sweden)

Krystyna Isakova

2014-01-01

Full Text Available We discuss some aspects of the fluid dynamics of vitreous substitutes in the vitreous chamber, focussing on the flow induced by rotations of the eye bulb. We use simple, yet not trivial, theoretical models to highlight mechanical concepts that are relevant to understand the dynamics of vitreous substitutes and also to identify ideal properties for vitreous replacement fluids. We first recall results by previous authors, showing that the maximum shear stress on the retina grows with increasing viscosity of the fluid up to a saturation value. We then investigate how the wall shear stress changes if a thin layer of aqueous humour is present in the vitreous chamber, separating the retina from the vitreous replacement fluid. The theoretical predictions show that the existence of a thin layer of aqueous is sufficient to substantially decrease the shear stress on the retina. We finally discuss a theoretical model that predicts the stability conditions of the interface between the aqueous and a vitreous substitute. We discuss the implications of this model to understand the mechanisms leading to the formation of emulsion in the vitreous chamber, showing that instability of the interface is possible in a range of parameters relevant for the human eye.

THE IMPACT OF IFRS NORMS ON INTERNAL GOVERNANCE MECHANISMS WITH REGARD TO SOCIO-ECONOMIC CONTEXT

Directory of Open Access Journals (Sweden)

Soumaya HERGLI

2016-11-01

Full Text Available The purpose of this paper is to examine the effect of International Financial Reporting Standards IFRS adoption on internal governance mechanisms with regard to socio-economic context. Empirical investigation was conducted to assess whether a company and an individual specifications can be presented as part of a general pattern. The results confirm that IFRS framework has introduced a new design of the accounting formalism facing a more complex activity leading to enlargement the discretionary space. Socio-economic factors explain perfectly the corporate governance behaviors and confirmed that the less powerful members of our firms sample expect and accept that power is distributed unequally, the leaders prefer to act as individuals rather than as members of groups, the management positions are generally held by men than by women, these members are threatened by ambiguous or unknown situations and finally, managers stand for the fostering in a society of pragmatic virtues oriented to future rewards, in particular perseverance, thrift and adapting to changing circumstances.

LITERATURE REVIEW ON CORPORATE GOVERNANCE - FIRM PERFORMANCE RELATIONSHIP

Directory of Open Access Journals (Sweden)

Pintea Mirela-Oana

2015-07-01

Full Text Available In the matter of corporate governance reforms, an important aspect is whether the implementation of corporate governance principles and codes has a positive impact on firm performance. The literature testing the relationship between different corporate governance mechanisms and firm performance is extensive. Over time, a lot of corporate governances mechanisms were studied in relation to firm performance and the most used are: CEO duality, board size, proportion of non- executive directors, board committees, ownership structure and concentration, managers’ compensation and incentives schemes. With time, different authors began to use more comprehensive measures for corporate governance rather than a single variable or a single governance mechanism, the so called corporate governance indexes. Regarding performance there are three main approaches to firm performance in social science research: research based on market prices, accounting ratios and total factor profitability.The most used performance measures are: Tobin’s Q, return on equity, return on asset and economic value added. In our paper, we present the studies undertaken since the 1990’s regarding the relationship between different mechanisms of corporate governance and firm performance and between corporate governance index and performance for both developed and developing countries around the world. Regarding the working tools used in this theoretical research we can mention the longitudinal method, by presenting the evolution in time of empirical studies on the research topic and the comparative method used in presenting the resulys of different studies mentioned in our paper. The results of the studies are inconclusive, some studies founded a strog positive relation, others founded a negative correlation between corporate governance and firm performance, while a third category of studies didn’t found any relationship at all. We used participative observation method by issuing

Disciplining governance in Africa : a comparison of the World Bank’s Country Policy and Institutional Assessment and the African Union’s African Peer Review Mechanism

NARCIS (Netherlands)

S. Kassa (Saba)

2017-01-01

markdownabstractThis study examines the promotion of governance in the African Continent. It compares the Country Policy and Institutional Assessment (CPIA) of the World Bank to the African Peer Review Mechanism (APRM) of the African Union. These governance assessments represent differing

A Novel Method of Mechanical Oxidation of CNT for Polymer Nanocomposite Application: Evaluation of Mechanical, Dynamic Mechanical, and Rheological Properties

Directory of Open Access Journals (Sweden)

Priyanka Pandey

2014-01-01

Full Text Available A new approach of oxidation of carbon nanotubes has been used to oxidize the CNTs. A comparative aspect of the mechanical oxidation and acid oxidation process has been established. FTIR analysis and titration method have shown the higher feasibility of the mechanical oxidation method to oxidize the CNTs. Comparatively less damage to the CNTs has been observed in case of mechanically oxidized as compared to acid oxidized CNTs. The mechanical properties of the nanocomposites reinforced with the acid oxidized CNT (ACNT and mechanically oxidized CNTs (McCNT were analyzed and relatively higher properties in the nanocomposites reinforced with McCNT were noticed. The less degree of entanglement in the McCNTs was noticed as compared to ACNTs. The dynamic mechanical analysis of the nanocomposites revealed much improved load transfer capability in the McCNT reinforced composites. Further, the rheological properties of the nanocomposites revealed the higher performance of McCNT reinforced composites.

Testing and Modeling of Mechanical Characteristics of Resistance Welding Machines

DEFF Research Database (Denmark)

Wu, Pei; Zhang, Wenqi; Bay, Niels

2003-01-01

for both upper and lower electrode systems. This has laid a foundation for modeling the welding process and selecting the welding parameters considering the machine factors. The method is straightforward and easy to be applied in industry since the whole procedure is based on tests with no requirements......The dynamic mechanical response of resistance welding machine is very important to the weld quality in resistance welding especially in projection welding when collapse or deformation of work piece occurs. It is mainly governed by the mechanical parameters of machine. In this paper, a mathematical...... model for characterizing the dynamic mechanical responses of machine and a special test set-up called breaking test set-up are developed. Based on the model and the test results, the mechanical parameters of machine are determined, including the equivalent mass, damping coefficient, and stiffness...

Mechanism governing heme synthesis reveals a GATA factor/heme circuit that controls differentiation.

Science.gov (United States)

Tanimura, Nobuyuki; Miller, Eli; Igarashi, Kazuhiko; Yang, David; Burstyn, Judith N; Dewey, Colin N; Bresnick, Emery H

2016-02-01

Metal ion-containing macromolecules have fundamental roles in essentially all biological processes throughout the evolutionary tree. For example, iron-containing heme is a cofactor in enzyme catalysis and electron transfer and an essential hemoglobin constituent. To meet the intense demand for hemoglobin assembly in red blood cells, the cell type-specific factor GATA-1 activates transcription of Alas2, encoding the rate-limiting enzyme in heme biosynthesis, 5-aminolevulinic acid synthase-2 (ALAS-2). Using genetic editing to unravel mechanisms governing heme biosynthesis, we discovered a GATA factor- and heme-dependent circuit that establishes the erythroid cell transcriptome. CRISPR/Cas9-mediated ablation of two Alas2 intronic cis elements strongly reduces GATA-1-induced Alas2 transcription, heme biosynthesis, and surprisingly, GATA-1 regulation of other vital constituents of the erythroid cell transcriptome. Bypassing ALAS-2 function in Alas2 cis element-mutant cells by providing its catalytic product 5-aminolevulinic acid rescues heme biosynthesis and the GATA-1-dependent genetic network. Heme amplifies GATA-1 function by downregulating the heme-sensing transcriptional repressor Bach1 and via a Bach1-insensitive mechanism. Through this dual mechanism, heme and a master regulator collaborate to orchestrate a cell type-specific transcriptional program that promotes cellular differentiation. © 2015 The Authors.

Governance or Governing – the Missing Link?

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Luminiţa Maria Crăciun

2010-07-01

Full Text Available Governance and governing are two distinct concepts, but they intertwine. “Good governing” exercises good influence on development. “Good governance” supposes first a relationship of power focused on a series of reforms structured at three levels: the political – administrative level, the economic level, and the level of civil society. As this dimension is difficult to measure, the qualitative evaluation of the governing act raised the interest of the World Bank researchers, who elaborated and monitored the dynamics of a set of indicators, which includes six major dimensions of the governing. A retrospective concerning the image of governing in Romania during the period from 1996 to 2005 suggests a modest increase of the score: from -0.138 (1996 to 0.008 (2002; that was partially achieved based on the voice and responsibility index and on the political stability index, not on those that measure more directly the administrative performance or the integrity of the governing act. For a comparative study, we chose seven countries for the purposes of analysis (two new European Union member states: Romania and Bulgaria; two older member countries of the European Union: Slovenia and Latvia; three non-member states: Moldova, Ukraine, and Georgia, which reveal the quality of the governing from a comparative perspective. Corruption control completes the image created by the analyzed indicators. The mere formal accomplishment of commitments made in the pre-accession activity, doubled by recent internal evolutions, bring doubts about the credibility of the anticorruption reforms, as Romania continues to be considered the country with the highest CPI in the European Union. The pessimism of public opinion and the fact that only 34% of the Romanian people consider that the level of corruption will decrease in the following three years constitutes an alarm signal addressed to the governance, in view of the real reformation of the administration system

The Adoption of Internal Audit as a Governance Control Mechanism in Australian Public Universities--Views from the CEOs

Science.gov (United States)

Christopher, Joe

2012-01-01

This study draws on the multi-theoretical approach to governance and the views of university chief executive officers (CEOs) to examine the extent to which internal auditing as a control mechanism is adopted in Australian public universities under an environment of change management. The findings highlight negative consequences of change and their…

The interplay of structural and relational governance in innovation alliances

NARCIS (Netherlands)

Garbade, P.J.P.; Omta, S.W.F.; Fortuin, F.T.J.M.

2016-01-01

The present paper aims to extend the discussion in the governance literature about whether structural and relational governance mechanisms complement or substitute each other in innovation alliances. Where structural governance mechanisms refer to the division of tasks within the alliance and to

Quantitative Study on the Dynamic Mechanism of Smart Low-Carbon City Development in China

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Bo Pang

2016-05-01

Full Text Available With the development of new generation technology and the low-carbon economy, the smart low-carbon city has become one of the academic hotspots. Many studies on it have begun; however, the dynamic mechanism is rarely involved. Therefore, this paper uses the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS method to creatively take a quantitative study on a Chinese smart low-carbon city’s dynamic mechanism. The results show that: (1 the three main dynamics of smart low-carbon city development in China are institutional and cultural conditions, facilities and functions conditions and economy and industry conditions, but the overall utility is relatively low; (2 the level of the dynamic operation mechanism of the Chinese smart low-carbon city is distinct between regions, indicating a diminishing spatial law from east to west and differences within regions; (3 the imbalance of the comprehensive dynamic mechanism and the operation status between smart low-carbon cities is prominent, showing a decreasing urban scale law of from big to small and differences within each scale, and a descending administration hierarchy law from high to low and differences within each class; (4 seven basic development patterns can be obtained, and most of the cities belong to the external strong/internal weak mode, which basically matches with its development realities. Finally, general policy recommendations and countermeasures of optimization and improvement are proposed.

Dynamic mechanical oscillations during metamorphosis of the monarch butterfly

Science.gov (United States)

Pelling, Andrew E; Wilkinson, Paul R; Stringer, Richard; Gimzewski, James K

2008-01-01

The mechanical oscillation of the heart is fundamental during insect metamorphosis, but it is unclear how morphological changes affect its mechanical dynamics. Here, the micromechanical heartbeat with the monarch chrysalis (Danaus plexippus) during metamorphosis is compared with the structural changes observed through in vivo magnetic resonance imaging (MRI). We employ a novel ultra-sensitive detection approach, optical beam deflection, in order to measure the microscale motions of the pupae during the course of metamorphosis. We observed very distinct mechanical contractions occurring at regular intervals, which we ascribe to the mechanical function of the heart organ. Motion was observed to occur in approximately 15 min bursts of activity with frequencies in the 0.4–1.0 Hz range separated by periods of quiescence during the first 83 per cent of development. In the final stages, the beating was found to be uninterrupted until the adult monarch butterfly emerged. Distinct stages of development were characterized by changes in frequency, amplitude, mechanical quality factor and de/repolarization times of the mechanical pulsing. The MRI revealed that the heart organ remains functionally intact throughout metamorphosis but undergoes morphological changes that are reflected in the mechanical oscillation. PMID:18682363

Corporate Governance, Sustainability and Capital Markets Orientation

OpenAIRE

Daniela M. Salvioni; Francesca Gennari

2014-01-01

Generally accepted principles of effective corporate governance have taken hold in the context of different models of governance, whose implementation is also linked to the share structure of the companies and to the dynamics of risk’s capital markets. Global companies need a global approach in the acquisition of consensus and financial resources, first of all through a correct development of the corporate governance activities and promoting a market-driven management inspired by long-term su...

Dynamic Characteristics of a Hydraulic Amplification Mechanism for Large Displacement Actuators Systems

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Xavier Arouette

2010-03-01

Full Text Available We have developed a hydraulic displacement amplification mechanism (HDAM and studied its dynamic response when combined with a piezoelectric actuator. The HDAM consists of an incompressible fluid sealed in a microcavity by two largely deformable polydimethylsiloxane (PDMS membranes. The geometry with input and output surfaces having different cross-sectional areas creates amplification. By combining the HDAM with micro-actuators, we can amplify the input displacement generated by the actuators, which is useful for applications requiring large deformation, such as tactile displays. We achieved a mechanism offering up to 18-fold displacement amplification for static actuation and 12-fold for 55 Hz dynamic actuation.

Governance Change and Institutional Adaptation: A Case Study from Harenna Forest, Ethiopia

Science.gov (United States)

Wakjira, Dereje T.; Fischer, Anke; Pinard, Michelle A.

2013-04-01

Many common pool resources have traditionally been managed through intricate local governance arrangements. Over time, such arrangements are confronted with manifold political, social, economic and ecological changes. However, the ways in which local governance arrangements react to such changes are poorly understood. Using the theoretical concept of institutional adaptation, we analyse the history of Harenna forest, Ethiopia, to examine processes of institutional change over the last 150 years. We find that the traditional institutions that governed Harenna's resources persisted, in essence, over time. However, these institutions were modified repeatedly to address changes caused by varying formal, supra-regional governance regimes, the development of markets for forest products, increasing population pressure and changes in formal property rights. A key mechanism for adaptation was combining elements from both informal and formal institutions, which allowed traditional rules to persist in the guise of more formal arrangements. Our findings also highlight several constraints of institutional adaptation. For example, by abolishing fora for collective decision-making, regime changes limited adaptive capacity. To conclude, we argue that such insights into traditional resource governance and its adaptability and dynamics over time are essential to develop sustainable approaches to participatory forest management for the future, both in Harenna and more generally.

Placing Teachers in Global Governance Agendas

Science.gov (United States)

Robertson, Susan L.

2012-01-01

This article examines the focus on teacher policies and practices by a range of global actors and explores their meaning for the governance of teachers. Through a historical and contemporary reading, I argue that an important shift in the locus of power to govern has taken place. I show how the mechanisms of global governance of teachers are being…

Dynamics and control of mechanical systems in offshore engineering

CERN Document Server

He, Wei; How, Bernard Voon Ee; Choo, Yoo Sang

2014-01-01

Dynamics and Control of Mechanical Systems in Offshore Engineering is a comprehensive treatment of marine mechanical systems (MMS) involved in processes of great importance such as oil drilling and mineral recovery. Ranging from nonlinear dynamic modeling and stability analysis of flexible riser systems, through advanced control design for an installation system with a single rigid payload attached by thrusters, to robust adaptive control for mooring systems, it is an authoritative reference on the dynamics and control of MMS. Readers will gain not only a complete picture of MMS at the system level, but also a better understanding of the technical considerations involved and solutions to problems that commonly arise from dealing with them. The text provides:                                                                                                                                 ...

The electricity generation adequacy problem: Assessing dynamic effects of capacity remuneration mechanisms

International Nuclear Information System (INIS)

Hary, Nicolas; Rious, Vincent; Saguan, Marcelo

2016-01-01

Following liberalization reforms, the ability of power markets to provide satisfactory incentives for capacity investments has become a major concern. In particular, current energy markets can exhibit a phenomenon of investment cycles, which generate phases of under and over-capacity, and hence additional costs and risks for generation adequacy. To cope with these issues, new mechanisms, called capacity remuneration mechanisms (CRM), have been (or will be) implemented. This paper assesses the dynamic effects of two CRMs, the capacity market and the strategic reserve mechanism, and studies to what extent they can reduce the investment cycles. Generation costs and shortage costs of both mechanisms are also compared to conclude on their effectivity and economic efficiency. A simulation model, based on system dynamics, is developed to study the functioning of both CRMs and the related investment decisions. The results highlight the benefits of deploying CRMs to solve the adequacy issue: shortages are strongly reduced compared to an energy-only market. Besides, the capacity market appears to be more beneficial, since it experiences fewer shortages and generation costs are lower. These comparisons can be used by policy makers (in particular in Europe, where these two CRMs are mainly debated) to determine which CRM to adopt. - Highlights: •A study of the dynamic effects of CRMs on generation investments is provided. •Capacity market and strategic reserve mechanism are compared. •Both CRMs reduce the cyclical tendencies prone to appear in energy-only market. •The capacity market experiences fewer shortages and generation costs are lower.

Conservation and aid: designing more effective investments in natural resource governance reform.

Science.gov (United States)

Nelson, Fred

2009-10-01

Biodiversity conservation outcomes are closely related to the rules and institutions governing resource use. Creating local incentives for conservation through more secure resource tenure is central to conservation outcomes on private and communal lands, where the preponderance of biodiversity occurs. Conservation efforts in sub-Saharan Africa are therefore centrally concerned with governance dynamics and institutional reform processes, such as the decentralization of property rights, and how best to achieve such reforms. Traditional mechanisms for financing conservation efforts in Africa rely heavily on funds channeled through multilateral and bilateral aid agencies. The history of development aid highlights a range of constraints these aid agencies face in terms of working toward more effective resource governance arrangements and promoting reforms. Government aid agencies possess incentives for promoting large-scale and short-term projects that maximize expenditure volumes and tend to define issues in technical rather than political terms. The history of development aid suggests that these and other characteristics of aid agencies impedes their ability to influence governance reform processes and that aid funding may discourage the adoption of reforms. Greater emphasis in African conservation financing needs to be placed on flexible, small-scale investments aligned to local interests and constituencies that prioritize innovation, learning, and experimentation. Additionally, more research is required that explores the linkages between conservation funding, donor decision-making processes, and governance reforms.

Investigation of deformation mechanisms of staggered nanocomposites using molecular dynamics

Science.gov (United States)

Mathiazhagan, S.; Anup, S.

2016-08-01

Biological materials with nanostructure of regularly or stair-wise staggered arrangements of hard platelets reinforced in a soft protein matrix have superior mechanical properties. Applications of these nanostructures to ceramic matrix composites could enhance their toughness. Using molecular dynamics simulations, mechanical behaviour of the bio-inspired nanocomposites is studied. Regularly staggered model shows better flow behaviour compared to stair-wise staggered model due to the symmetrical crack propagation along the interface. Though higher stiffness and strength are obtained for stair-wise staggered models, rapid crack propagation reduces the toughness. Arresting this crack propagation could lead to superior mechanical properties in stair-wise staggered models.

Practice and effectiveness of internal corporate governance mechanisms in Saudi Arabia Stock Market: A review of empirical evidence

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Marai Awidat

2017-01-01

Full Text Available The aim of this paper is to shed light on the Saudi corporate governance code, its practices and effectiveness. To do so, the paper conducted a detailed review of the articles of the code related to internal corporate governance mechanisms and the previous studies regarding its effectiveness in Saudi stock market context. The main finding is that the provisions of Saudi corporate governance code are adequate. Annual reports (2009-2014 show an increase in the level of the compliance by listed companies, indicating that the code is achieving its aims. However, the empirical evidence seems to suggest that the code has an insignificant impact on company's performance and mitigating earnings management. The main reasons behind that are the following: the code is still in its early stages, there is weak legal enforcement, and there are also some social, cultural, and economic factors. Therefore, the code needs more time for good practice and improvement to achieve its purposes.

Effect of thermally reduced graphene oxide on dynamic mechanical properties of carbon fiber/epoxy composite

Science.gov (United States)

Adak, Nitai Chandra; Chhetri, Suman; Murmu, Naresh Chandra; Samanta, Pranab; Kuila, Tapas

2018-03-01

The Carbon fiber (CF)/epoxy composites are being used in the automotive and aerospace industries owing to their high specific mechanical strength to weight ratio compared to the other conventional metal and alloys. However, the low interfacial adhesion between fiber and polymer matrix results the inter-laminar fracture of the composites. Effects of different carbonaceous nanomaterials i.e., carbon nanotubes (CNT), graphene nanosheets (GNPs), graphene oxide (GO) etc. on the static mechanical properties of the composites were investigated in detail. Only a few works focused on the improvement of the dynamic mechanical of the CF/epoxy composites. Herein, the effect of thermally reduced grapheme oxide (TRGO) on the dynamic mechanical properties of the CF/epoxy composites was investigated. At first, GO was synthesized using modified Hummers method and then reduced the synthesized GO inside a vacuum oven at 800 °C for 5 min. The prepared TRGO was dispersed in the epoxy resin to modify the epoxy matrix. Then, a number of TRGO/CF/epoxy laminates were manufactured incorporating different wt% of TRGO by vacuum assisted resin transfer molding (VARTM) technique. The developed laminates were cured at room temperature for 24 h and then post cured at 120 °C for 2 h. The dynamic mechanical analyzer (DMA 8000 Perkin Elmer) was used to examine the dynamic mechanical properties of the TRGO/CF/epoxy composites according to ASTM D7028. The dimension of the specimen was 44×10×2.4 mm3 for the DMA test. This test was carried out under flexural loading mode (duel cantilever) at a frequency of 1 Hz and amplitude of 50 μm. The temperature was ramped from 30 to 200 °C with a heating rate of 5 °C min-1. The dynamic mechanical analysis of the 0.2 wt% TRGO incorporated CF/epoxy composites showed ~ 96% enhancement in storage modulus and ~ 12 °C increments in glass transition temperature (Tg) compared to the base CF/epoxy composites. The fiber-matrix interaction was studied by Cole

A Model for Determining Optimal Governance Structure in DoD Acquisition Projects in a Performance-Based Environment

Science.gov (United States)

2010-04-30

combating market dynamism (Aldrich, 1979; Child, 1972), which is a result of evolving technology, shifting prices, or variance in product availability...primary determinant of behavior (Baron & Hannan, 1994). Concepts such as trust play a prominent role in network explanations (Achrol & Kotler , 1999). 4...and that governance relies on combinations of market , social, and/or authority-based mechanisms more than any one of these exclusively. • In a

Dynamic Mechanical and Nanofibrous Topological Combinatory Cues Designed for Periodontal Ligament Engineering.

Science.gov (United States)

Kim, Joong-Hyun; Kang, Min Sil; Eltohamy, Mohamed; Kim, Tae-Hyun; Kim, Hae-Won

2016-01-01

Complete reconstruction of damaged periodontal pockets, particularly regeneration of periodontal ligament (PDL) has been a significant challenge in dentistry. Tissue engineering approach utilizing PDL stem cells and scaffolding matrices offers great opportunity to this, and applying physical and mechanical cues mimicking native tissue conditions are of special importance. Here we approach to regenerate periodontal tissues by engineering PDL cells supported on a nanofibrous scaffold under a mechanical-stressed condition. PDL stem cells isolated from rats were seeded on an electrospun polycaprolactone/gelatin directionally-oriented nanofiber membrane and dynamic mechanical stress was applied to the cell/nanofiber construct, providing nanotopological and mechanical combined cues. Cells recognized the nanofiber orientation, aligning in parallel, and the mechanical stress increased the cell alignment. Importantly, the cells cultured on the oriented nanofiber combined with the mechanical stress produced significantly stimulated PDL specific markers, including periostin and tenascin with simultaneous down-regulation of osteogenesis, demonstrating the roles of topological and mechanical cues in altering phenotypic change in PDL cells. Tissue compatibility of the tissue-engineered constructs was confirmed in rat subcutaneous sites. Furthermore, in vivo regeneration of PDL and alveolar bone tissues was examined under the rat premaxillary periodontal defect models. The cell/nanofiber constructs engineered under mechanical stress showed sound integration into tissue defects and the regenerated bone volume and area were significantly improved. This study provides an effective tissue engineering approach for periodontal regeneration-culturing PDL stem cells with combinatory cues of oriented nanotopology and dynamic mechanical stretch.

Thermo-dynamical contours of electronic-vibrational spectra simulated using the statistical quantum-mechanical methods

DEFF Research Database (Denmark)

Pomogaev, Vladimir; Pomogaeva, Anna; Avramov, Pavel

2011-01-01

Three polycyclic organic molecules in various solvents focused on thermo-dynamical aspects were theoretically investigated using the recently developed statistical quantum mechanical/classical molecular dynamics method for simulating electronic-vibrational spectra. The absorption bands of estradiol...

Leveraging non-binding instruments for global health governance: reflections from the Global AIDS Reporting Mechanism for WHO reform.

Science.gov (United States)

Taylor, A L; Alfven, T; Hougendobler, D; Tanaka, S; Buse, K

2014-02-01

As countries contend with an increasingly complex global environment with direct implications for population health, the international community is seeking novel mechanisms to incentivize coordinated national and international action towards shared health goals. Binding legal instruments have garnered increasing attention since the World Health Organization adopted its first convention in 2003. This paper seeks to expand the discourse on future global health lawmaking by exploring the potential value of non-binding instruments in global health governance, drawing on the case of the 2001 United Nations General Assembly Special Session Declaration of Commitment on HIV/AIDS. In other realms of international concern ranging from the environment to human rights to arms control, non-binding instruments are increasingly used as effective instruments of international cooperation. The experience of the Global AIDS Reporting Mechanism, established pursuant to the Declaration, evidences that, at times, non-binding legal instruments can offer benefits over slower, more rigid binding legal approaches to governance. The global AIDS response has demonstrated that the use of a non-binding instrument can be remarkably effective in galvanizing increasingly deep commitments, action, reporting compliance and ultimately accountability for results. Based on this case, the authors argued that non-binding instruments deserve serious consideration by the international community for the future of global health governance, including in the context of WHO reform. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Mechanisms of private meta-governance: an analysis of global private governance for sustainable development

NARCIS (Netherlands)

Glasbergen, P.

2011-01-01

One of the main characteristics of global governance for sustainable development is its fragmentation. Next to public regulations, there are often many private regulations in force on the same issue, which are induced by collaborations between businesses and NGOs. Traditionally, it is assumed that

The missing link in nanomaterials governance: industrial dynamics and downstream policies

OpenAIRE

Rafols, Ismael; van Zwanenberg, Patrick; Morgan, Molly; Nightingale, Paul; Smith, Adrian

2009-01-01

In this article we explore the analytical and policy implications of widening the governance of nanomaterials from the focus on risk regulation to a broader focus on the governance of innovation. To do this, we have analysed the impact of industrial activities on nanotechnology governance, while previous studies have concentrated on risk appraisal, public perceptions, public engagement, regulatory frameworks and related policies. We argue that the specific characteristics of the industrial dy...

Coupling Langevin Dynamics With Continuum Mechanics: Exposing the Role of Sarcomere Stretch Activation Mechanisms to Cardiac Function

Directory of Open Access Journals (Sweden)

Takumi Washio

2018-04-01

Full Text Available High-performance computing approaches that combine molecular-scale and macroscale continuum mechanics have long been anticipated in various fields. Such approaches may enrich our understanding of the links between microscale molecular mechanisms and macroscopic properties in the continuum. However, there have been few successful examples to date owing to various difficulties associated with overcoming the large spatial (from 1 nm to 10 cm and temporal (from 1 ns to 1 ms gaps between the two scales. In this paper, we propose an efficient parallel scheme to couple a microscopic model using Langevin dynamics for a protein motor with a finite element continuum model of a beating heart. The proposed scheme allows us to use a macroscale time step that is an order of magnitude longer than the microscale time step of the Langevin model, without loss of stability or accuracy. This reduces the overhead required by the imbalanced loads of the microscale computations and the communication required when switching between scales. An example of the Langevin dynamics model that demonstrates the usefulness of the coupling approach is the molecular mechanism of the actomyosin system, in which the stretch-activation phenomenon can be successfully reproduced. This microscopic Langevin model is coupled with a macroscopic finite element ventricle model. In the numerical simulations, the Langevin dynamics model reveals that a single sarcomere can undergo spontaneous oscillation (15 Hz accompanied by quick lengthening due to cooperative movements of the myosin molecules pulling on the common Z-line. Also, the coupled simulations using the ventricle model show that the stretch-activation mechanism contributes to the synchronization of the quick lengthening of the sarcomeres at the end of the systolic phase. By comparing the simulation results given by the molecular model with and without the stretch-activation mechanism, we see that this synchronization contributes to

A Dynamic Pricing Reverse Auction-Based Resource Allocation Mechanism in Cloud Workflow Systems

Directory of Open Access Journals (Sweden)

Xuejun Li

2016-01-01

Full Text Available Market-oriented reverse auction is an efficient and cost-effective method for resource allocation in cloud workflow systems since it can dynamically allocate resources depending on the supply-demand relationship of the cloud market. However, during the auction the price of cloud resource is usually fixed, and the current resource allocation mechanisms cannot adapt to the changeable market properly which results in the low efficiency of resource utilization. To address such a problem, a dynamic pricing reverse auction-based resource allocation mechanism is proposed. During the auction, resource providers can change prices according to the trading situation so that our novel mechanism can increase the chances of making a deal and improve efficiency of resource utilization. In addition, resource providers can improve their competitiveness in the market by lowering prices, and thus users can obtain cheaper resources in shorter time which would decrease monetary cost and completion time for workflow execution. Experiments with different situations and problem sizes are conducted for dynamic pricing-based allocation mechanism (DPAM on resource utilization and the measurement of Time⁎Cost (TC. The results show that our DPAM can outperform its representative in resource utilization, monetary cost, and completion time and also obtain the optimal price reduction rates.

On the mechanical vibrator-earth contact geometry and its dynamics

NARCIS (Netherlands)

Noorlandt, R.P.; Drijkoningen, G.G.

2016-01-01

The geometry of the contact between a vibrator and the earth underneath influences the dynamics of the vibrator. Although a vibrator might appear to be well-coupled with the earth on a macroscale, perfect coupling certainly does not occur on the microscale. With the aid of contact mechanical

The computer code EURDYN - 1 M (release 1) for transient dynamic fluid-structure interaction. Pt.1: governing equations and finite element modelling

International Nuclear Information System (INIS)

Donea, J.; Fasoli-Stella, P.; Giuliani, S.; Halleux, J.P.; Jones, A.V.

1980-01-01

This report describes the governing equations and the finite element modelling used in the computer code EURDYN - 1 M. The code is a non-linear transient dynamic program for the analysis of coupled fluid-structure systems; It is designed for safety studies on LMFBR components (primary containment and fuel subassemblies)

Experimental studies of the dynamic mechanical response of a single polymer chain

DEFF Research Database (Denmark)

Thormann, Esben; Evans, Drew R.; Craig, Vincent S. J.

2006-01-01

The high-frequency and low-amplitude dynamic mechanical response from a single poly(vinyl alcohol) chain was investigated. Modification of a commercial atomic force microscope enabled high-frequency and low-amplitude periodic deformations of polymer chains during extension to be performed...... mechanical response from poly(vinyl alcohol) does not differ from its static response. This result is not unexpected as poly(vinyl alcohol) is a highly flexible polymer with intramolecular relaxation processes taking place on a short time scale. The choice of a polymer with a fast relaxation allows its...... static properties to be recovered from the dynamic measurements and enables the method suggested in this paper for decoupling the polymer response from the hydrodynamic response to be validated....

Dynamics of a Circular Mindlin Plate under Mechanical Loading and Elevated Temperature

Directory of Open Access Journals (Sweden)

Warminska Anna

2016-01-01

Full Text Available Dynamics of a nonlinear circular Midlin plate is studied in the paper. The mathematical model represented by partial differential equations includes nonlinear geometrical terms resulted from large displacements. The plate is subjected to mechanical and thermal loadings. The dynamics of a coupled thermo-mechanical problem is reduced from partial to ordinary differential equations. Considering the first mode reduction and uniformly distributed temperature just a single nonlinear differential equation is obtained. The bifurcation analysis shows that elevated temperature shifts the rezonanse curve and new solutions arise. Depending on initial conditions this may lead to buckling phenomenon and then relatively small oscillations around this state, symmetric periodic oscillations of large amplitude, or irregular oscillations.

Coupling of lipid membrane elasticity and in-plane dynamics

Science.gov (United States)

Tsang, Kuan-Yu; Lai, Yei-Chen; Chiang, Yun-Wei; Chen, Yi-Fan

2017-07-01

Biomembranes exhibit liquid and solid features concomitantly with their in-plane fluidity and elasticity tightly regulated by cells. Here, we present experimental evidence supporting the existence of the dynamics-elasticity correlations for lipid membranes and propose a mechanism involving molecular packing densities to explain them. This paper thereby unifies, at the molecular level, the aspects of the continuum mechanics long used to model the two membrane features. This ultimately may elucidate the universal physical principles governing the cellular phenomena involving biomembranes.

Timing Embryo Segmentation: Dynamics and Regulatory Mechanisms of the Vertebrate Segmentation Clock

Science.gov (United States)

Resende, Tatiana P.; Andrade, Raquel P.; Palmeirim, Isabel

2014-01-01

All vertebrate species present a segmented body, easily observed in the vertebrate column and its associated components, which provides a high degree of motility to the adult body and efficient protection of the internal organs. The sequential formation of the segmented precursors of the vertebral column during embryonic development, the somites, is governed by an oscillating genetic network, the somitogenesis molecular clock. Herein, we provide an overview of the molecular clock operating during somite formation and its underlying molecular regulatory mechanisms. Human congenital vertebral malformations have been associated with perturbations in these oscillatory mechanisms. Thus, a better comprehension of the molecular mechanisms regulating somite formation is required in order to fully understand the origin of human skeletal malformations. PMID:24895605

Multifractal spectrum analysis of nonlinear dynamical mechanisms in China’s agricultural futures markets

Science.gov (United States)

Chen, Shu-Peng; He, Ling-Yun

2010-04-01

Based on Partition Function and Multifractal Spectrum Analysis, we investigated the nonlinear dynamical mechanisms in China’s agricultural futures markets, namely, Dalian Commodity Exchange (DCE for short) and Zhengzhou Commodity Exchange (ZCE for short), where nearly all agricultural futures contracts are traded in the two markets. Firstly, we found nontrivial multifractal spectra, which are the empirical evidence of the existence of multifractal features, in 4 representative futures markets in China, that is, Hard Winter wheat (HW for short) and Strong Gluten wheat (SG for short) futures markets from ZCE and Soy Meal (SM for short) futures and Soy Bean No.1 (SB for short) futures markets from DCE. Secondly, by shuffling the original time series, we destroyed the underlying nonlinear temporal correlation; thus, we identified that long-range correlation mechanism constitutes major contributions in the formation in the multifractals of the markets. Thirdly, by tracking the evolution of left- and right-half spectra, we found that there exist critical points, between which there are different behaviors, in the left-half spectra for large price fluctuations; but for the right-hand spectra for small price fluctuations, the width of those increases slowly as the delay t increases in the long run. Finally, the dynamics of large fluctuations is significantly different from that of the small ones, which implies that there exist different underlying mechanisms in the formation of multifractality in the markets. Our main contributions focus on that we not only provided empirical evidence of the existence of multifractal features in China agricultural commodity futures markets; but also we pioneered in investigating the sources of the multifractality in China’s agricultural futures markets in current literature; furthermore, we investigated the nonlinear dynamical mechanisms based on spectrum analysis, which offers us insights into the underlying dynamical mechanisms in

Dynamics and genetic fuzzy neural network vibration control design of a smart flexible four-bar linkage mechanism

International Nuclear Information System (INIS)

Rong Bao; Rui Xiaoting; Tao Ling

2012-01-01

In this paper, a dynamic modeling method and an active vibration control scheme for a smart flexible four-bar linkage mechanism featuring piezoelectric actuators and strain gauge sensors are presented. The dynamics of this smart mechanism is described by the Discrete Time Transfer Matrix Method of Multibody System (MS-DTTMM). Then a nonlinear fuzzy neural network control is employed to suppress the vibration of this smart mechanism. For improving the dynamic performance of the fuzzy neural network, a genetic algorithm based on the MS-DTTMM is designed offline to tune the initial parameters of the fuzzy neural network. The MS-DTTMM avoids the global dynamics equations of the system, which results in the matrices involved are always very small, so the computational efficiency of the dynamic analysis and control system optimization can be greatly improved. Formulations of the method as well as a numerical simulation are given to demonstrate the proposed dynamic method and control scheme.

Tracking the mechanical dynamics of human embryonic stem cell chromatin

Directory of Open Access Journals (Sweden)

Hinde Elizabeth

2012-12-01

Full Text Available Abstract Background A plastic chromatin structure has emerged as fundamental to the self-renewal and pluripotent capacity of embryonic stem (ES cells. Direct measurement of chromatin dynamics in vivo is, however, challenging as high spatiotemporal resolution is required. Here, we present a new tracking-based method which can detect high frequency chromatin movement and quantify the mechanical dynamics of chromatin in live cells. Results We use this method to study how the mechanical properties of chromatin movement in human embryonic stem cells (hESCs are modulated spatiotemporally during differentiation into cardiomyocytes (CM. Notably, we find that pluripotency is associated with a highly discrete, energy-dependent frequency of chromatin movement that we refer to as a ‘breathing’ state. We find that this ‘breathing’ state is strictly dependent on the metabolic state of the cell and is progressively silenced during differentiation. Conclusions We thus propose that the measured chromatin high frequency movements in hESCs may represent a hallmark of pluripotency and serve as a mechanism to maintain the genome in a transcriptionally accessible state. This is a result that could not have been observed without the high spatial and temporal resolution provided by this novel tracking method.

MARKET-BASED MECHANISM IN PUBLIC SERVICE DELIVERY IN LOCAL GOVERNMENT IN POLAND – A BRIEF OVERVIEW

Directory of Open Access Journals (Sweden)

Dawid Sześciło

2013-12-01

Full Text Available The reintroduction of local self-government at the level of communes (gminy in 1990 opened the way for an in-depth reform of the local governance framework in Poland. This included not only the legal, organizational and fiscal autonomisation of local communities, but also went in line with general trends concerning the transformation of the public sector. Therefore, among the core elements of the transformation we may identify the extensive privatization of the public service provision schemes. In Poland, this process was not based on the theoretical background of New Public Management, as was the case in a number of Western countries. Instead, it was natural consequence of the rebirth of a market economy with a limited public sector and the intense development of the private market. Those trends were, however, compatible with the NPM programme. The expansion of market-based mechanisms in public service delivery is one of its pillars. This article provides a historical overview of the development of market-based arrangements in public service provision at the most basic level of Polish local government. It is focused mainly on a legal framework, but also includes some observations on the practical side of this process.

Long-term dynamic loading improves the mechanical properties of chondrogenic mesenchymal stem cell-laden hydrogel

Directory of Open Access Journals (Sweden)

AH Huang

2010-02-01

Full Text Available Mesenchymal stem cells (MSCs are an attractive cell source for cartilage tissue engineering given their ability to undergo chondrogenesis in 3D culture systems. Mechanical forces play an important role in regulating both cartilage development and MSC chondrogenic gene expression, however, mechanical stimulation has yet to enhance the mechanical properties of engineered constructs. In this study, we applied long-term dynamic compression to MSC-seeded constructs and assessed whether varying pre-culture duration, loading regimens and inclusion of TGF-beta3 during loading would influence functional outcomes and these phenotypic transitions. Loading initiated before chondrogenesis decreased functional maturation, although chondrogenic gene expression increased. In contrast, loading initiated after chondrogenesis and matrix elaboration further improved the mechanical properties of MSC-based constructs, but only when TGF-beta3 levels were maintained and under specific loading parameters. Although matrix quantity was not affected by dynamic compression, matrix distribution, assessed histologically and by FT-IRIS analysis, was significantly improved on the micro- (pericellular and macro- (construct expanse scales. Further, whole genome expression profiling revealed marked shifts in the molecular topography with dynamic loading. These results demonstrate, for the first time, that dynamic compressive loading initiated after a sufficient period of chondro-induction and with sustained TGF-beta exposure enhances matrix distribution and the mechanical properties of MSC-seeded constructs.

Cure behavior, compression set and dynamic mechanical properties of EPDM/NBR blend vulcanizates

Energy Technology Data Exchange (ETDEWEB)

Park, C.Y. [Pukyong National Univeristy, Pusan (Korea)

2001-03-01

The ethylene propylene diene terpolymer (EPDM) blends with acrylonitrile butadiene rubber (NBR) were prepared by mechanical mixing method. Mooney viscosity, cure behaviors, compression set and dynamic mechanical properties were subsequently examined. Dynamic characteristics of the entire blends determined from a Rheovibron generally showed two glass transitions (T{sub g}'s), -43 deg. C and -4 deg. C for NBR and EPDM, respectively. The tan {delta} peak monotonically shifted toward the higher temperature with increasing NBR content. It was also found that the optimum cure time was significantly decreased with loading of NBR. (author). 13 refs., 4 tabs., 9 figs.

Dynamic Response and Failure Mechanism of Brittle Rocks Under Combined Compression-Shear Loading Experiments

Science.gov (United States)

Xu, Yuan; Dai, Feng

2018-03-01

A novel method is developed for characterizing the mechanical response and failure mechanism of brittle rocks under dynamic compression-shear loading: an inclined cylinder specimen using a modified split Hopkinson pressure bar (SHPB) system. With the specimen axis inclining to the loading direction of SHPB, a shear component can be introduced into the specimen. Both static and dynamic experiments are conducted on sandstone specimens. Given carefully pulse shaping, the dynamic equilibrium of the inclined specimens can be satisfied, and thus the quasi-static data reduction is employed. The normal and shear stress-strain relationships of specimens are subsequently established. The progressive failure process of the specimen illustrated via high-speed photographs manifests a mixed failure mode accommodating both the shear-dominated failure and the localized tensile damage. The elastic and shear moduli exhibit certain loading-path dependence under quasi-static loading but loading-path insensitivity under high loading rates. Loading rate dependence is evidently demonstrated through the failure characteristics involving fragmentation, compression and shear strength and failure surfaces based on Drucker-Prager criterion. Our proposed method is convenient and reliable to study the dynamic response and failure mechanism of rocks under combined compression-shear loading.

Dynamic simulation of a beta-type Stirling engine with cam-drive mechanism via the combination of the thermodynamic and dynamic models

Energy Technology Data Exchange (ETDEWEB)

Cheng, Chin-Hsiang; Yu, Ying-Ju [Department of Aeronautics and Astronautics, National Cheng Kung University, No. 1, Ta-Shieh Road, Tainan, Taiwan (China)

2011-02-15

Dynamic simulation of a beta-type Stirling engine with cam-drive mechanism used in concentrating solar power system has been performed. A dynamic model of the mechanism is developed and then incorporated with the thermodynamic model so as to predict the transient behavior of the engine in the hot-start period. In this study, the engine is started from an initial rotational speed. The torques exerted by the flywheel of the engine at any time instant can be calculated by the dynamic model as long as the gas pressures in the chambers, the mass inertia, the friction force, and the external load have been evaluated. The instantaneous rotation speed of the engine is then determined by integration of the equation of rotational motion with respect to time, which in return affects the instantaneous variations in pressure and other thermodynamic properties of the gas inside the chambers. Therefore, the transient variations in gas properties inside the engine chambers and the dynamic behavior of the engine mechanism should be handled simultaneously via the coupling of the thermodynamic and dynamic models. An extensive parametric study of the effects of different operating and geometrical parameters has been performed, and results regarding the effects of mass moment of inertia of the flywheel, initial rotational speed, initial charged pressure, heat source temperature, phase angle, gap size, displacer length, and piston stroke on the engine transient behavior are investigated. (author)

IT Business Cases in Local Government

DEFF Research Database (Denmark)

Nielsen, Peter Axel; Persson, John Stouby

2012-01-01

Effective management of value creation with information technology (IT) is increasingly important for local governments (e.g., municipalities). The business case is a tool that has increased popularity in both the public and private sector to support the management of value creation with IT....... However, experiences from local government reveal difficulties in developing effective IT business cases beyond simple cost savings. Based on collaborative action research with Danish municipalities we present insights on contemporary IT business case practices. Based on these insights we formulate...... lessons for business case practices in local government that we have incorporated into a business case method; that has subsequently been evaluated by IT managers in local government. These lessons have been synthesized into the four principles: minimal contents, benefits ownership, dynamic utility...

Maritime governance speed, flow, form process

CERN Document Server

Roe, Michael

2016-01-01

This book provides an original analysis of the problems facing global governance and in particular that of one of the most globalised of all industries – shipping. Central to all global trade and its dramatic growth, shipping faces difficulties of governance stemming from its every globalised nature. The current characteristics of global governance – nation-state fixation, anachronistic institutions, inadequate stakeholder involvement and an over-domination of owner interests are dwarfed by the problems of stasis and fixation which means that policies to address problems of safety, the environment and security are inadequate. This book provides a full and wide ranging discussion of how governance can be animated in a global context so that the dynamism of the maritime industry and its problems can be prevented, regulated and understood. Its unique approach to governance makes it essential reading for all maritime policy-makers and those analysing maritime issues, alongside those with an interest in govern...

Exploration of government policy structure which support and block energy transition process in indonesia using system dynamics model

Science.gov (United States)

Destyanto, A. R.; Silalahi, T. D.; Hidayatno, A.

2017-11-01

System dynamic modeling is widely used to predict and simulate the energy system in several countries. One of the applications of system dynamics is to evaluate national energy policy alternatives, and energy efficiency analysis. Using system dynamic modeling, this research aims to evaluate the energy transition policy that has been implemented in Indonesia on the past conversion program of kerosene to LPG for household cook fuel consumption, which considered as successful energy transition program implemented since 2007. This research is important since Indonesia considered not yet succeeded to execute another energy transition program on conversion program of oil fuel to gas fuel for transportation that has started since 1989. The aim of this research is to explore which policy intervention that has significant contribution to support or even block the conversion program. Findings in this simulation show that policy intervention to withdraw the kerosene supply and government push to increase production capacity of the support equipment industries (gas stove, regulator, and LPG Cylinder) is the main influence on the success of the program conversion program.

Hubungan antara Corporate Governance dan Variabel Pengurang Masalah Agensi

Directory of Open Access Journals (Sweden)

Zaenal Arifin

2009-08-01

Full Text Available The main objective of this research is to investigate whether there are a significant relationship be¬tween corporate governance and agency-problem-reducing variables. The corporate governance is concern on all stakeholders’ interest while the agency variables are concern on one of the most important stakeholders’ that is the stockholders-interest. Theoretically, there should be a significant relationship between the corporate govern¬ance and the agency-problem-reducing variables. Using 52 Indonesian listed companies in 2001 that had been investigated by Indonesian Institute for Corporate Governance (IICG for the companies’ practice of corporate governance and presented on SWA Magazine, this research found that no relationship between the corporate governance and the agency-problem-reducing variables. There are some possible explanations for this finding. First, reducing agency problems does not perceived (by investor affecting the companies’ practice of corporate governance. Second, the bonding mechanisms to reduce the free cash flows by increasing the dividend payment or increasing the debt and monitoring by the independent board of directors are not an effective mechanism to re¬duce agency problems. So these mechanisms do not correlate to the companies’ practice of corporate govern¬ance. Third, the score of corporate governance released by IICG are not valid. Further investigations are needed to find the true explanation.Key words: Corporate Governance, Masalah Agensi

European Level Test of Romanian Enterprise Governance

Directory of Open Access Journals (Sweden)

Niculae Feleaga

2006-04-01

Full Text Available The corporate governance is a central and dynamic aspect of the businesses. The term governance comes from the latin “gubernare”, meaning to guide and supposes that the corporate governance imply equally both the leadership function and that of control. As is known there are more ways of defining the enterprise governance starting from the simple stones, which focus on the enterprise and its shareholders, to the most complex ones incorporating individual or departamental responsability to implement a given function of the companies and which implies many other groups of persons. Responsability is the consequence of the law and reglementation application or contract agreements.

European Level Test of Romanian Enterprise Governance

Directory of Open Access Journals (Sweden)

Niculae Feleaga

2006-02-01

Full Text Available The corporate governance is a central and dynamic aspect of the businesses. The term governance comes from the latin “gubernare”, meaning to guide and supposes that the corporate governance imply equally both the leadership function and that of control. As is known there are more ways of defining the enterprise governance starting from the simple stones, which focus on the enterprise and its shareholders, to the most complex ones incorporating individual or departamental responsability to implement a given function of the companies and which implies many other groups of persons. Responsability is the consequence of the law and reglementation application or contract agreements.

Co-Evolutionary Mechanisms of Emotional Bursts in Online Social Dynamics and Networks

Directory of Open Access Journals (Sweden)

Bosiljka Tadić

2013-11-01

Full Text Available Collective emotional behavior of users is frequently observed on various Web portals; however, its complexity and the role of emotions in the acting mechanisms are still not thoroughly understood. In this work, using the empirical data and agent-based modeling, a parallel analysis is performed of two archetypal systems—Blogs and Internet-Relayed-Chats—both of which maintain self-organized dynamics but not the same communication rules and time scales. The emphasis is on quantifying the collective emotions by means of fractal analysis of the underlying processes as well as topology of social networks, which arise and co-evolve in these stochastic processes. The results reveal that two distinct mechanisms, which are based on different use of emotions (an emotion is characterized by two components, arousal and valence, are intrinsically associated with two classes of emergent social graphs. Their hallmarks are the evolution of communities in accordance with the excess of the negative emotions on popular Blogs, on one side, and smooth spreading of the Bot’s emotional impact over the entire hierarchical network of chats, on the other. Another emphasis of this work is on the understanding of nonextensivity of the emotion dynamics; it was found that, in its own way, each mechanism leads to a reduced phase space of the emotion components when the collective dynamics takes place. That a non-additive entropy describes emotion dynamics, is further confirmed by computing the q-generalized Kolmogorov-Sinai entropy rate in the empirical data of chats as well as in the simulations of interacting emotional agents and Bots.

Integrating climate change into governance at the municipal scale

DEFF Research Database (Denmark)

Wejs, Anja

2014-01-01

traditions and perceptions. This article examines dif- ferent approaches to CC governance and the institutional dynamics that occur in the integration process within eight Danish municipalities in the initial phase of integrating CC. The results show three different governance approaches related to climate...

Ideas and institutions in global governance - the case of microcredit

DEFF Research Database (Denmark)

Aagaard, Peter

There is a growing demand for effective strategic problem solving in relation to a wide array of global policy problems such as AIDS, poverty, global warming, etc. This makes the introduction of new policy ideas for institutional change increasingly important in global governance. But researchers...... need a new approach in order to better grasp the complexity in global problem solving. We need to know more about how ideas emerge, spread and transform in a complex, networked global environment. New literature on institutional dynamics can inform the literature on global governance networks......, especially when it comes to the meta-governance of global networks. Based on a case study of microcredit and its emergence as a policy idea in development policy, the paper will illustrate the use of institutional dynamic conceptualisation in global governance....

Government control or low carbon lifestyle? – Analysis and application of a novel selective-constrained energy-saving and emission-reduction dynamic evolution system

International Nuclear Information System (INIS)

Fang, Guochang; Tian, Lixin; Fu, Min; Sun, Mei

2014-01-01

This paper explores a novel selective-constrained energy-saving and emission-reduction (ESER) dynamic evolution system, analyzing the impact of cost of conserved energy (CCE), government control, low carbon lifestyle and investment in new technology of ESER on energy intensity and economic growth. Based on artificial neural network, the quantitative coefficients of the actual system are identified. Taking the real situation in China for instance, an empirical study is undertaken by adjusting the parameters of the actual system. The dynamic evolution behavior of energy intensity and economic growth in reality are observed, with the results in perfect agreement with actual situation. The research shows that the introduction of CCE into ESER system will have certain restrictive effect on energy intensity in the earlier period. However, with the further development of the actual system, carbon emissions could be better controlled and energy intensity would decline. In the long run, the impacts of CCE on economic growth are positive. Government control and low carbon lifestyle play a decisive role in controlling ESER system and declining energy intensity. But the influence of government control on economic growth should be considered at the same time and the controlling effect of low carbon lifestyle on energy intensity should be strengthened gradually, while the investment in new technology of ESER can be neglected. Two different cases of ESER are proposed after a comprehensive analysis. The relations between variables and constraint conditions in the ESER system are harmonized remarkably. A better solution to carry out ESER is put forward at last, with numerical simulations being carried out to demonstrate the results. - Highlights: • Use of nonlinear dynamical method to model the selective-constrained ESER system. • Monotonic evolution curves of energy intensity and economic growth are obtained. • Detailed analysis of the game between government control and low

Chaotic population dynamics and biology of the top-predator

International Nuclear Information System (INIS)

Rai, Vikas; Upadhyay, Ranjit Kumar

2004-01-01

We study how the dynamics of a food chain depends on the biology of the top-predator. We consider two model food chains with specialist and generalist top-predators. Both types of food chains display same type of chaotic behavior, short-term recurrent chaos; but the generating mechanisms are drastically different. Food chains with specialist top-predators are dictated by exogenous stochastic factors. On the contrary, the dynamics of those with the generalist top-predator is governed by deterministic changes in system parameters. The study also suggests that robust chaos would be a rarity

Graphene Statistical Mechanics

Science.gov (United States)

Bowick, Mark; Kosmrlj, Andrej; Nelson, David; Sknepnek, Rastko

2015-03-01

Graphene provides an ideal system to test the statistical mechanics of thermally fluctuating elastic membranes. The high Young's modulus of graphene means that thermal fluctuations over even small length scales significantly stiffen the renormalized bending rigidity. We study the effect of thermal fluctuations on graphene ribbons of width W and length L, pinned at one end, via coarse-grained Molecular Dynamics simulations and compare with analytic predictions of the scaling of width-averaged root-mean-squared height fluctuations as a function of distance along the ribbon. Scaling collapse as a function of W and L also allows us to extract the scaling exponent eta governing the long-wavelength stiffening of the bending rigidity. A full understanding of the geometry-dependent mechanical properties of graphene, including arrays of cuts, may allow the design of a variety of modular elements with desired mechanical properties starting from pure graphene alone. Supported by NSF grant DMR-1435794

Static and Dynamic Amplification Using Strong Mechanical Coupling

KAUST Repository

Ilyas, Saad

2016-07-28

Amplifying the signal-to-noise ratio of resonant sensors is vital toward the effort to miniaturize devices into the sub-micro and nano regimes. In this paper, we demonstrate theoretically and experimentally, amplification through mechanically coupled microbeams. The device is composed of two identical clamped-clamped beams, made of polyimide, connected at their middle through a third beam, which acts as a mechanical coupler. Each of the clamped-clamped microbeams and the coupler are designed to be actuated separately, hence providing various possibilities of actuation and sensing. The coupled resonator is driven into resonance near its first resonance mode and its dynamic behavior is explored via frequency sweeps. The results show significant amplification in the resonator amplitude when the signal is measured at the midpoint of the coupler compared with the response of the individual uncoupled beams. The static pull-in characteristics of the resonator are also studied. It is shown that the compliant mechanical coupler can serve as a low-power radio frequency switch actuated at low voltage loads. [2016-0100

The dynamic and quasi-static mechanical response of three aluminum armor alloys: 5059, 5083 and 7039

Energy Technology Data Exchange (ETDEWEB)

Perez-Bergquist, Sara J., E-mail: sara.perezbergquist@gmail.com [Materials Science and Technology Division, Los Alamos National Laboratory, NM 87545 (United States); Gray, G.T.; Cerreta, Ellen K.; Trujillo, Carl P.; Perez-Bergquist, Alex [Materials Science and Technology Division, Los Alamos National Laboratory, NM 87545 (United States)

2011-11-15

Highlights: {yields} Aluminum alloys for use in armor applications. {yields} Mechanical response in dynamic and quasi-static regimes with temperature dependence. {yields} Shear localization with evidence of early stages of dynamic recrystallization. - Abstract: The mechanical response and microstructural evolution of aluminum alloys 5083, 5059 and 7039 was examined in compression and shear in both the quasi-static (0.001 s{sup -1}) and dynamic ({approx}2000 s{sup -1}) strain rate regimes. Electron Back Scattered Diffraction was utilized for detailed post-mortem analysis of the specimens following loading. The mechanical responses in shear were found to be strain-rate sensitive. At the slowest strain rates, all of the alloys had relatively large volumes of highly deformed material with 5083 and 5059 having the largest shear affected volumes. The dynamic strain rate test samples all formed highly compact shear localized volumes across the sheared zone with 7039 consistently displaying the narrowest shear regions. The morphology of these shear bands, along with the limited hardening during deformation, indicate a mechanism change at the higher strain rates. Higher resolution orientation image mapping has shown that between the three alloys there are varying degrees of crystallographic order within the shear bands. Transmission electron microscopy revealed various stages of dynamic recrystallization were present suggesting that while low strain rate deformation is controlled by dislocation multiplication and glide, high strain and strain-rate deformation is influenced in part due to mechanical recrystallization.

Study of the dynamics of the lower hybrid wave during current drive in tokamaks and of the Weyl-Wigner in quantum mechanics

International Nuclear Information System (INIS)

Bizarro, J.P.

1993-10-01

A comprehensive and detailed investigation is presented on the dynamics of the lower hybrid wave during current drive in tokamaks in situations where toroidally induced ray stochasticity is important and on the Weyl-Wigner formalism for rotation angle and angular momentum variables in quantum mechanics. It is shown that ray-tracing and Fokker-Planck codes are reliable tools for modelling the physics of lower-hybrid current drive provided a large number of rays is used when stochastic effects are important, and, in particular, that such codes are capable of reproducing the experimentally observed features of the hard X-ray emission. The balance between the wave damping and the stochastic divergence of nearby ray trajectories appears to be of great importance in governing the dynamics of the launched power spectrum and in establishing the characteristics of the deposition patterns. The implications of rotational periodicity and of angular momentum quantization for the Weyl-Wigner formalism are analyzed. Particular attention is paid to discreteness and its consequences: importance of evenness and oddness, use of two difference operators instead of one differential operator. 24 refs

Unpacking the mechanisms of the EU ‘throughput’ governance legitimacy

DEFF Research Database (Denmark)

Chatzopoulou, Sevasti

2015-01-01

The proliferation of EU agencies, referred to as agencification phenomenon, constitutes a significant EU institutional innovation. Agencification aimed to provide information, promote efficiency, decrease politicization and generate standards based on specialised technical knowledge. However...... this article claims that in order to assess the overall legitimacy of the EU regulatory governance through agencies, the ‘throughput’ criterion needs to be considered. Although important, the ‘input’ (politics) and ‘output’ (policy) criteria fail to capture what happens within the actual governance (process...

Keeping Government Secrecy Safe: Beyond Whack-a-Mole

NARCIS (Netherlands)

Curtin, D.M.

2011-01-01

The concept of secrecy as a mechanism for not providing government information, on the one hand, and the commitment to openness of government, on the other, reflect certain historical understandings of the relationship between a government, citizens, officials and information. Within democratic

A primer of analytical mechanics

CERN Document Server

Strocchi, Franco

2018-01-01

This book presents the basic elements of Analytical Mechanics, starting from the physical motivations that favor it with respect to the Newtonian Mechanics in Cartesian coordinates. Rather than presenting Analytical Mechanics mainly as a formal development of Newtonian Mechanics, it highlights its effectiveness due to the following five important achievements: 1) the most economical description of time evolution in terms of the minimal set of coordinates, so that there are no constraint forces in their evolution equations; 2) the form invariance of the evolution equations, which automatically solves the problem of fictitious forces; 3) only one scalar function encodes the formulation of the dynamics, rather than the full set of vectors which describe the forces in Cartesian Newtonian Mechanics; 4) in the Hamiltonian formulation, the corresponding evolution equations are of first order in time and are fully governed by the Hamiltonian function (usually corresponding to the energy); 5) the emergence of the Hami...

The Earth at a glance 2009: the sustainable development governance

International Nuclear Information System (INIS)

Jacquet, P.; Pachauri, R.; Tubiana, L.

2009-01-01

How to implement the sustainable development? More than 15 years after the Rio conference, the question is still pending, renewed by the intense mobilization of non-governmental actors, organizations, companies, or local communities. Observing the inadequacy of the present day governance system is not sufficient and it is advisable to identify among the numerous dynamics in progress, the beginnings of a new governance. The sustainable development governance is the theme of the 2009 issue of 'the Earth at a glance' book with the ambition to contribute to the reflexion about the present day governance system and its desirable evolutions. Content: the 2008 events status and the schedule of the main 2009 meetings; the 2009 world sustainable development governance: a system to the sustainable development test, dynamics of a changing world, sustainably managing complexity; the sustainable development benchmarks: maps, tables, chronologies, economic, social and environmental syntheses for an original mapping of sustainable development in the world. (J.S.)

The association of hospital governance with innovation in Taiwan.

Science.gov (United States)

Yang, Chen-Wei; Yan, Yu-Hua; Fang, Shih-Chieh; Inamdar, Syeda Noorein; Lin, Hsien-Cheng

2018-01-01

Hospitals in Taiwan are facing major changes and innovation is increasingly becoming a critical factor for remaining competitive. One determinant that can have a significant impact on innovation is hospital governance. However, there is limited prior research on the relationship between hospital governance and innovation. The purpose of this study is to propose a conceptual framework to hypothesize the relationship between governance mechanisms and innovation and to empirically test the hypotheses in hospital organizations. We examine the relationship between governance mechanisms and innovation using data on 102 hospitals in Taiwan from the Taiwan Joint Commission on Hospital Accreditation and Quality Improvement. We model governance mechanisms using board structure, information transparency and strategic decision-making processes. For our modeling and data analysis we use measurement and structural models. We find that in hospital governance, information transparency and strategic decision making did impact innovation. However, governance structure did not. To facilitate innovation, hospital boards can increase information transparency and improve the decision-making process when considering strategic investments in innovative initiatives. To remain competitive, hospital boards need to develop and monitor indices that measure hospital innovation to ensure ongoing progress. Copyright © 2017 John Wiley & Sons, Ltd.

Separating grain boundary migration mechanisms in molecular dynamics simulations

International Nuclear Information System (INIS)

Ulomek, Felix; Mohles, Volker

2016-01-01

In molecular dynamics (MD) simulations of grain boundary (GB) migration it is quite common to find a temperature dependence of GB mobility that deviates strongly from an Arrhenius-type dependence. This usually indicates that more than one mechanism is actually active. With the goal to separate different GB migration mechanisms we investigate a Σ7 <111> 38.2° GB by MD using an EAM potential for aluminium. To drive the GB with a well-known and adjustable force, the energy conserving orientational driving force (ECO DF) is used that had been introduced recently. The magnitude of the DF and the temperature are varied. This yielded a high and a low temperature range for the GB velocity, with a transition temperature that depends on the magnitude of the DF. A method is introduced which allows both a visual and a statistical characterization of GB motion on a per atom basis. These analyses reveal that two mechanisms are active in this GB, a shuffling mechanism and its initiation. These mechanisms operate in a sequential, coupled manner. Based on this, a simple model is introduced that describes all simulated GB velocities (and hence the mobility) very well, including the transition between the dominating mechanisms.

Dynamics in a nonlinear Keynesian good market model

International Nuclear Information System (INIS)

Naimzada, Ahmad; Pireddu, Marina

2014-01-01

In this paper, we show how a rich variety of dynamical behaviors can emerge in the standard Keynesian income-expenditure model when a nonlinearity is introduced, both in the cases with and without endogenous government spending. A specific sigmoidal functional form is used for the adjustment mechanism of income with respect to the excess demand, in order to bound the income variation. With the aid of analytical and numerical tools, we investigate the stability conditions, bifurcations, as well as periodic and chaotic dynamics. Globally, we study multistability phenomena, i.e., the coexistence of different kinds of attractors

Adaptive governance of riverine and wetland ecosystem goods and services

Science.gov (United States)

Adaptive governance and adaptive management have developed over the past quarter century in response to institutional and organizational failures, and unforeseen changes in natural resource dynamics. Adaptive governance provides a context for managing known and unknown consequenc...

Dynamics in microbial communities: Unraveling mechanisms to identify principles

Energy Technology Data Exchange (ETDEWEB)

Konopka, Allan; Lindemann, Stephen R.; Fredrickson, Jim K.

2015-07-01

Diversity begets higher order properties such as functional stability and robustness in microbial communities, but principles that inform conceptual (and eventually predictive) models of community dynamics are lacking. Recent work has shown that selection as well as dispersal and drift shape communities, but the mechanistic bases for assembly of communities and the forces that maintain their function in the face of environmental perturbation are not well understood. Conceptually, some interactions among community members could generate endogenous dynamics in composition, even in the absence of environmental changes. These endogenous dynamics are further perturbed by exogenous forcing factors to produce a richer network of community interactions, and it is this “system” that is the basis for higher order community properties. Elucidation of principles that follow from this conceptual model requires identifying the mechanisms that (a) optimize diversity within a community and (b) impart community stability. The network of interactions between organisms can be an important element by providing a buffer against disturbance beyond the effect of functional redundancy, as alternative pathways with different combinations of microbes can be recruited to fulfill specific functions.

Dynamic analysis on market structure of China's coal industry

International Nuclear Information System (INIS)

Yang, Qing; Zhang, Lei; Wang, Xin

2017-01-01

According to industrial organization theory, market structure is a crucial factor to market performance. Based on the VAR model and the data from 1994 to 2014, we revealed the dynamic response route of the market structure to these factors and the change process of contribution rate of these factors to the market structure. It shows that market structure is inertial adjustment; technology advance and industry policy have continuous effects on improvement of market concentration ratio; market size and production scale have sustained negative effects on market concentration ratio; fixed capital has barrier effect, which is mainly the entry barrier effect at the beginning, and then the exit barrier effect continues to play a leading role. Therefore, the government has no need to introduce special policies to encourage merger or expansion on the capacity as enterprises would do it spontaneously; it is necessary to make market access system stricter, to improve exit compensation mechanism and to promote technological innovation; all these policies need dynamic adjustment based on the stages of economic cycle. - Highlights: • The adjustment mechanism of China's coal market structure is revealed. • Technology and industry policy are significant factors to optimize the market structure. • The government need not introduce special policy to encourage merger. • The market access system should be stricter. • Policies strength should be dynamically adjusted based on the economic cycle.

Dynamical chaos: systems of classical mechanics

International Nuclear Information System (INIS)

Loskutov, A Yu

2007-01-01

This article is a methodological manual for those who are interested in chaotic dynamics. An exposition is given on the foundations of the theory of deterministic chaos that originates in classical mechanics systems. Fundamental results obtained in this area are presented, such as elements of the theory of nonlinear resonance and the Kolmogorov-Arnol'd-Moser theory, the Poincare-Birkhoff fixed-point theorem, and the Mel'nikov method. Particular attention is given to the analysis of the phenomena underlying the self-similarity and nature of chaos: splitting of separatrices and homoclinic and heteroclinic tangles. Important properties of chaotic systems - unpredictability, irreversibility, and decay of temporal correlations - are described. Models of classical statistical mechanics with chaotic properties, which have become popular in recent years - billiards with oscillating boundaries - are considered. It is shown that if a billiard has the property of well-developed chaos, then perturbations of its boundaries result in Fermi acceleration. But in nearly-integrable billiard systems, excitations of the boundaries lead to a new phenomenon in the ensemble of particles, separation of particles in accordance their velocities. If the initial velocity of the particles exceeds a certain critical value characteristic of the given billiard geometry, the particles accelerate; otherwise, they decelerate. (methodological notes)

Polycentrism in Global Health Governance Scholarship

Science.gov (United States)

Tosun, Jale

2018-01-01

Drawing on an in-depth analysis of eight global health networks, a recent essay in this journal argued that global health networks face four challenges to their effectiveness: problem definition, positioning, coalition-building, and governance. While sharing the argument of the essay concerned, in this commentary, we argue that these analytical concepts can be used to explicate a concept that has implicitly been used in global health governance scholarship for quite a few years. While already prominent in the discussion of climate change governance, for instance, global health governance scholarship could make progress by looking at global health governance as being polycentric. Concisely, polycentric forms of governance mix scales, mechanisms, and actors. Drawing on the essay, we propose a polycentric approach to the study of global health governance that incorporates coalitionbuilding tactics, internal governance and global political priority as explanatory factors. PMID:29325406

The melting of stable glasses is governed by nucleation-and-growth dynamics

International Nuclear Information System (INIS)

Jack, Robert L.; Berthier, Ludovic

2016-01-01

We discuss the microscopic mechanisms by which low-temperature amorphous states, such as ultrastable glasses, transform into equilibrium fluids, after a sudden temperature increase. Experiments suggest that this process is similar to the melting of crystals, thus differing from the behaviour found in ordinary glasses. We rationalize these observations using the physical idea that the transformation process takes place close to a “hidden” equilibrium first-order phase transition, which is observed in systems of coupled replicas. We illustrate our views using simulation results for a simple two-dimensional plaquette spin model, which is known to exhibit a range of glassy behaviour. Our results suggest that nucleation-and-growth dynamics, as found near ordinary first-order transitions, is also the correct theoretical framework to analyse the melting of ultrastable glasses. Our approach provides a unified understanding of multiple experimental observations, such as propagating melting fronts, large kinetic stability ratios, and “giant” dynamic length scales. We also provide a comprehensive discussion of available theoretical pictures proposed in the context of ultrastable glass melting.

Structure and dynamics of hydrated Fe(II) and Fe(III) ions. Quantum mechanical and molecular mechanical simulations

International Nuclear Information System (INIS)

Remsungnen, T.

2002-11-01

Classical molecular dynamics (MD) and combined em ab initio quantum mechanical/molecular mechanical molecular dynamics (QM/MM-MD) simulations have been performed to investigate structural, dynamical and energetical properties of Fe(II), and Fe(III) transition metal ions in aqueous solution. In the QM/MM-MD simulations the ion and its first hydration sphere were treated at the Hartree-Fock ab initio quantum mechanical level, while ab initio generated pair plus three-body potentials were employed for the remaining system. For the classical MD simulation the pair plus three-body potential were employed for all ion-water interactions. The coordination number of the first hydration shell is 100 % of 6 in both cases. The number of waters in the second hydration shell obtained from classical simulations are 13.4 and 15.1 for Fe(II) and Fe(III), respectively, while QM/MM-MD gives the values of 12.4 and 13.4 for Fe(II) and Fe(III). The energies of hydration obtained from MD and QM/MM-MD for Fe(II) are 520 and 500 kcal/mol, and for Fe(III) 1160 and 1100 kcal/mol respectively. The mean residence times of water in the second shell obtained from QM/MM-MD are 24 and 48 ps for Fe(II) and Fe(III), respectively. In contrast to the data obtained from classical MD simulation, the QM/MM-MD values are all in good agreement with the experimental data available. These investigations and results clearly indicate that many-body effects are essential for the proper description of all properties of the aqueous solution of both Fe(II) and Fe(III) ions. (author)

Dynamic coarse-graining fills the gap between atomistic simulations and experimental investigations of mechanical unfolding

Science.gov (United States)

Knoch, Fabian; Schäfer, Ken; Diezemann, Gregor; Speck, Thomas

2018-01-01

We present a dynamic coarse-graining technique that allows one to simulate the mechanical unfolding of biomolecules or molecular complexes on experimentally relevant time scales. It is based on Markov state models (MSMs), which we construct from molecular dynamics simulations using the pulling coordinate as an order parameter. We obtain a sequence of MSMs as a function of the discretized pulling coordinate, and the pulling process is modeled by switching among the MSMs according to the protocol applied to unfold the complex. This way we cover seven orders of magnitude in pulling speed. In the region of rapid pulling, we additionally perform steered molecular dynamics simulations and find excellent agreement between the results of the fully atomistic and the dynamically coarse-grained simulations. Our technique allows the determination of the rates of mechanical unfolding in a dynamical range from approximately 10-8/ns to 1/ns thus reaching experimentally accessible time regimes without abandoning atomistic resolution.

Modern trends in international researches in the sphere of electronic governance (in the case of publications of the international journal Electronic Government)

OpenAIRE

V. M. Dreshpak

2017-01-01

Current trends of studying the problems of electronic government by world scientific community have been revealed in the article using the analysis of publications in the international journal Electronic Government. It has been noted that the peculiarity of modern research in the sphere of electronic government is that this sphere is changing constantly and dynamically under the influence of many factors and is being modernized together with the development of information and communication te...

Dynamic mechanical assessment of muscle hyperalgesia in humans: The dynamic algometer

Science.gov (United States)

Finocchietti, Sara; Graven-Nielsen, Thomas; Arendt-Nielsen, Lars

2015-01-01

BACKGROUND: Musculoskeletal pain is often associated with a nonhomogeneous distribution of mechanical hyperalgesia. Consequently, new methods able to detect this distribution are needed. OBJECTIVE: To develop and test a new method for assessing muscle hyperalgesia with high temporal and spatial resolution that provides complementary information compared with information obtained by traditional static pressure algometry. METHODS: The dynamic pressure algometer was tested bilaterally on the tibialis anterior muscle in 15 healthy subjects and compared with static pressure algometry. The device consisted of a wheel that was rolled over the muscle tissue with a fixed velocity and different predefined forces. The pain threshold force was determined and pain intensity to a fixed-force stimulation was continuously rated on a visual analogue scale while the wheel was rolling over the muscle. The pressure pain sensitivity was evaluated before, during, and after muscle pain and hyperalgesia induced unilaterally by either injection of hypertonic saline (0.5 mL, 6%) into the tibialis anterior or eccentric exercise evoking delayed-onset muscle soreness (DOMS). RESULTS: The intraclass correlation coefficient was >0.88 for the dynamic thresholds; thus, the method was reliable. Compared with baseline, both techniques detected hyperalgesia at the saline injection site and during DOMS (Palgometer also detected the widespread, patchy distribution of sensitive loci during DOMS, which was difficult to evaluate using static pressure algometry. DISCUSSION AND CONCLUSION: The present study showed that dynamic pressure algometry is a reliable tool for evaluating muscle hyperalgesia (threshold and pain rating) with high temporal and spatial resolution. It can be applied as a simple clinical bed-side test and as a quantitative tool in pharmacological profiling studies. PMID:25664539

Role of Mitochondrial Dynamics in Neuronal Development: Mechanism for Wolfram Syndrome.

Science.gov (United States)

Cagalinec, Michal; Liiv, Mailis; Hodurova, Zuzana; Hickey, Miriam Ann; Vaarmann, Annika; Mandel, Merle; Zeb, Akbar; Choubey, Vinay; Kuum, Malle; Safiulina, Dzhamilja; Vasar, Eero; Veksler, Vladimir; Kaasik, Allen

2016-07-01

Deficiency of the protein Wolfram syndrome 1 (WFS1) is associated with multiple neurological and psychiatric abnormalities similar to those observed in pathologies showing alterations in mitochondrial dynamics. The aim of this study was to examine the hypothesis that WFS1 deficiency affects neuronal function via mitochondrial abnormalities. We show that down-regulation of WFS1 in neurons leads to dramatic changes in mitochondrial dynamics (inhibited mitochondrial fusion, altered mitochondrial trafficking, and augmented mitophagy), delaying neuronal development. WFS1 deficiency induces endoplasmic reticulum (ER) stress, leading to inositol 1,4,5-trisphosphate receptor (IP3R) dysfunction and disturbed cytosolic Ca2+ homeostasis, which, in turn, alters mitochondrial dynamics. Importantly, ER stress, impaired Ca2+ homeostasis, altered mitochondrial dynamics, and delayed neuronal development are causatively related events because interventions at all these levels improved the downstream processes. Our data shed light on the mechanisms of neuronal abnormalities in Wolfram syndrome and point out potential therapeutic targets. This work may have broader implications for understanding the role of mitochondrial dynamics in neuropsychiatric diseases.

Role of Mitochondrial Dynamics in Neuronal Development: Mechanism for Wolfram Syndrome.

Directory of Open Access Journals (Sweden)

Michal Cagalinec

2016-07-01

Full Text Available Deficiency of the protein Wolfram syndrome 1 (WFS1 is associated with multiple neurological and psychiatric abnormalities similar to those observed in pathologies showing alterations in mitochondrial dynamics. The aim of this study was to examine the hypothesis that WFS1 deficiency affects neuronal function via mitochondrial abnormalities. We show that down-regulation of WFS1 in neurons leads to dramatic changes in mitochondrial dynamics (inhibited mitochondrial fusion, altered mitochondrial trafficking, and augmented mitophagy, delaying neuronal development. WFS1 deficiency induces endoplasmic reticulum (ER stress, leading to inositol 1,4,5-trisphosphate receptor (IP3R dysfunction and disturbed cytosolic Ca2+ homeostasis, which, in turn, alters mitochondrial dynamics. Importantly, ER stress, impaired Ca2+ homeostasis, altered mitochondrial dynamics, and delayed neuronal development are causatively related events because interventions at all these levels improved the downstream processes. Our data shed light on the mechanisms of neuronal abnormalities in Wolfram syndrome and point out potential therapeutic targets. This work may have broader implications for understanding the role of mitochondrial dynamics in neuropsychiatric diseases.

Governing Individual Knowledge Sharing Behavior

DEFF Research Database (Denmark)

Minbaeva, Dana; Pedersen, Torben

2010-01-01

The emerging Knowledge Governance Approach asserts the need to build microfoundations grounded in individual action. Toward this goal, using the Theory of Planned Behavior, we aim to explain individual knowledge sharing behavior as being determined by the intention to share knowledge and its...... antecedents: attitude toward knowledge sharing, subjective norms, and perceived behavioral control. In addition, we consider managerial interventions (governance mechanisms) that managers can employ to influence the identified antecedents and thereby govern individual knowledge sharing behavior. We test...... a positive effect on subjective norms and perceived behavioral control, respectively....

Adaptive approaches to biosecurity governance.

Science.gov (United States)

Cook, David C; Liu, Shuang; Murphy, Brendan; Lonsdale, W Mark

2010-09-01

This article discusses institutional changes that may facilitate an adaptive approach to biosecurity risk management where governance is viewed as a multidisciplinary, interactive experiment acknowledging uncertainty. Using the principles of adaptive governance, evolved from institutional theory, we explore how the concepts of lateral information flows, incentive alignment, and policy experimentation might shape Australia's invasive species defense mechanisms. We suggest design principles for biosecurity policies emphasizing overlapping complementary response capabilities and the sharing of invasive species risks via a polycentric system of governance. © 2010 Society for Risk Analysis

Enterprise investment, local government intervention and coal overcapacity: The case of China

International Nuclear Information System (INIS)

Zhang, Yanfang; Zhang, Ming; Liu, Yue; Nie, Rui

2017-01-01

Long-term management of China's coal overcapacity depends on the targeted policy guidance on industry production capacity expansion in the overcapacity formation process. In this study, coal enterprise and local government are treated as game participants, and a three-stage dynamic game model has been developed to depict the boosting effect of the game behavior of coal enterprise's and local government's capacity investments in different markets of supply and demand. The results are shown in the following: (1) local government has been the 'behind-the-scenes' operator of over-investment and redundant construction, and its excessive interventions in coal industry investment have been the primary cause of overcapacity formation; (2) when the market is in short supply, coal enterprise's optimal behavior is to continuously increase the rate of investment growth until it reaches the threshold to obtain the maximum excess profits, ultimately leading to overinvestment in the industry; and (3) the key factors affecting the game abilities of coal enterprise and local government are the market's self-regulation and the central government's supervision intensity. Although the Chinese government, a highly vertically oriented bureaucratic structure, is implementing a mandatory de-capacity policy to alleviate the intensity of excessive coal capacity, it is not a long-term regularization on the supply-side reform. - Highlights: • The formation of China's coal overcapacity is studied from capacity investors. • A three-stage game is developed to depict the boosting effect of coal overcapacity. • Local government has been the 'behind-the-scenes' operators of coal overcapacity. • Coal enterprise's optimal strategy is reaching an investment-max with undersupply. • Chinese government should rely more on market mechanisms instead of intervention.

Evaluation of ethanol aged PVDF: diffusion, crystallinity and dynamic mechanical thermal properties

International Nuclear Information System (INIS)

Silva, Agmar J.J.; Costa, Marysilvia F.

2015-01-01

This work discuss firstly the effect of the ethanol fuel absorption by PVDF at 60°C through mass variation tests. A Fickian character was observed for the ethanol absorption kinetics of the aged PVDF at 60°C. In the second step, the dynamic mechanical thermal properties (E’, E’, E” and tan δ) of the PVDF were evaluated through dynamic mechanical thermal analysis (DMTA). The chemical structure of the materials was analyzed by X-ray diffraction analysis (XRD), and significant changes in the degree of crystallinity were verified after the aging. However, DMTA results showed a reduction in the storage modulus (E') of the aged PVDF, which was associated to diffusion of ethanol and swelling of the PVDF, which generated a prevailing plasticizing effect and led to reduction of its structural stiffness. (author)

Towards a fluid and multiscalar governance of extractive resources ...

African Journals Online (AJOL)

Political geographies of oil investigate extractive value chains with an emphasis on governance and scales, analysing the role that territories and especially spatial networks play in these dynamics. While underlining the limits and gaps of territorial governance, as it is nowadays theorized and used in the academic literature, ...

'Pop-Up' Governance: developing internal governance frameworks for consortia: the example of UK10K.

Science.gov (United States)

Kaye, Jane; Muddyman, Dawn; Smee, Carol; Kennedy, Karen; Bell, Jessica

2015-01-01

Innovations in information technologies have facilitated the development of new styles of research networks and forms of governance. This is evident in genomics where increasingly, research is carried out by large, interdisciplinary consortia focussing on a specific research endeavour. The UK10K project is an example of a human genomics consortium funded to provide insights into the genomics of rare conditions, and establish a community resource from generated sequence data. To achieve its objectives according to the agreed timetable, the UK10K project established an internal governance system to expedite the research and to deal with the complex issues that arose. The project's governance structure exemplifies a new form of network governance called 'pop-up' governance. 'Pop-up' because: it was put together quickly, existed for a specific period, was designed for a specific purpose, and was dismantled easily on project completion. In this paper, we use UK10K to describe how 'pop-up' governance works on the ground and how relational, hierarchical and contractual governance mechanisms are used in this new form of network governance.

Assessment of deep dynamic mechanical sensitivity in individuals with tension-type headache: The dynamic pressure algometry.

Science.gov (United States)

Palacios-Ceña, M; Wang, K; Castaldo, M; Guerrero-Peral, Á; Caminero, A B; Fernández-de-Las-Peñas, C; Arendt-Nielsen, L

2017-09-01

To explore the validity of dynamic pressure algometry for evaluating deep dynamic mechanical sensitivity by assessing its association with headache features and widespread pressure sensitivity in tension-type headache (TTH). One hundred and eighty-eight subjects with TTH (70% women) participated. Deep dynamic sensitivity was assessed with a dynamic pressure algometry set (Aalborg University, Denmark © ) consisting of 11 different rollers including fixed levels from 500 g to 5300 g. Each roller was moved at a speed of 0.5 cm/s over a 60-mm horizontal line covering the temporalis muscle. Dynamic pain threshold (DPT-level of the first painful roller) was determined and pain intensity during DPT was rated on a numerical pain rate scale (NPRS, 0-10). Headache clinical features were collected on a headache diary. As gold standard, static pressure pain thresholds (PPT) were assessed over temporalis, C5/C6 joint, second metacarpal, and tibialis anterior muscle. Side-to-side consistency between DPT (r = 0.843, p  r > 0.656, all p headaches supporting that deep dynamic pressure sensitivity within the trigeminal area is consistent with widespread pressure sensitivity. Assessing deep static and dynamic somatic tissue pain sensitivity may provide new opportunities for differentiated diagnostics and possibly a new tool for assessing treatment effects. The current study found that dynamic pressure algometry in the temporalis muscle was associated with widespread pressure pain sensitivity in individuals with tension-type headache. The association was independent of the frequency of headaches. Assessing deep static and dynamic somatic tissue pain sensitivity may provide new opportunities for differentiated diagnostics and possibly a tool for assessing treatment effects. © 2017 European Pain Federation - EFIC®.

Geometry, mechanics, and dynamics the legacy of Jerry Marsden

CERN Document Server

Holm, Darryl; Patrick, George; Ratiu, Tudor

2015-01-01

This book illustrates the broad range of Jerry Marsden’s mathematical legacy in areas of geometry, mechanics, and dynamics, from very pure mathematics to very applied, but always with a geometric perspective. Each contribution develops its material from the viewpoint of geometric mechanics beginning at the very foundations, introducing readers to modern issues via illustrations in a wide range of topics. The twenty refereed papers contained in this volume are based on lectures and research performed during the month of July 2012 at the Fields Institute for Research in Mathematical Sciences, in a program in honor of Marsden's legacy. The unified treatment of the wide breadth of topics treated in this book will be of interest to both experts and novices in geometric mechanics. Experts will recognize applications of their own familiar concepts and methods in a wide variety of fields, some of which they may never have approached from a geometric viewpoint. Novices may choose topics that interest them among the ...

Dynamic Modeling and Control of Electromechanical Coupling for Mechanical Elastic Energy Storage System

Directory of Open Access Journals (Sweden)

Yang Yu

2013-01-01

Full Text Available The structural scheme of mechanical elastic energy storage (MEES system served by permanent magnet synchronous motor (PMSM and bidirectional converters is designed. The aim of the research is to model and control the complex electromechanical system. The mechanical device of the complex system is considered as a node in generalized coordinate system, the terse nonlinear dynamic model of electromechanical coupling for the electromechanical system is constructed through Lagrange-Maxwell energy method, and the detailed deduction of the mathematical model is presented in the paper. The theory of direct feedback linearization (DFL is applied to decouple the nonlinear dynamic model and convert the developed model from nonlinear to linear. The optimal control theory is utilized to accomplish speed tracking control for the linearized system. The simulation results in three different cases show that the proposed nonlinear dynamic model of MEES system is correct; the designed algorithm has a better control performance in contrast with the conventional PI control.

The Dynamics of Decentralization Arrangements in Indonesia Constitutional System

Directory of Open Access Journals (Sweden)

Haposan Siallagan

2016-06-01

Full Text Available Local autonomy has long been implemented in Indonesia and has been experiencing a number of phases within governmental system. This writing is intended to fathom the dynamics of decentralization arrangement indeed. The discussion it-self shows that according to the substances in a number of decentralization policy which had/has been issued, the dynamics of local autonomy arrangements (as regulated in many decentralization policies are inclining to be captured in a broad meaning, which is frequently known as a broadest local autonomy. Through local autonomy mechanism, local governments are given a flexibility in order to manage and administer their own domestic household. In order to maximize the implementation of widest local autonomy, local government has to be pushed to be well prepared in handling many local governmental tasks. Such preparations are related to human resources capacity, the competences in running the tasks, and financial management capacity.

Particle spin dynamics as the grassmann variant of classical mechanics

International Nuclear Information System (INIS)

Berezin, F.A.; Marinov, M.S.

1976-01-01

A generalization of the calssical mechanics is presented. The dynamical variables are assumed to be elements of an algebra with anticommuting generators (The Grassmann algebra). The action functional and the Poisson brackets are defined. The equations of motion are deduced from the variational principle. The dynamics is described also by means of the Liouville equation for the phase-space distribution. The canonical quantization lead phase-space path integral approach to the quantum theory is also formulated. The theory is applied to describe the particle spin. Classical description of the spin precession and of the spin-orbital forces is given. The phase-space distribution and the interaction with an external field are also considered

Re-Inventing Shared Governance: Implications for Organisational Culture and Institutional Leadership

Science.gov (United States)

Stensaker, Bjorn; Vabo, Agnete

2013-01-01

Shared governance has been a key historical characteristic of higher education although this form of governance has come under increased pressure in recent decades. It is often argued that shared governance is less relevant for tackling the challenges related to a more dynamic environment of the sector. This paper discusses underlying premises for…

Routes to chaos in continuous mechanical systems: Part 2. Modelling transitions from regular to chaotic dynamics

International Nuclear Information System (INIS)

Krysko, A.V.; Awrejcewicz, J.; Papkova, I.V.; Krysko, V.A.

2012-01-01

In second part of the paper both classical and novel scenarios of transition from regular to chaotic dynamics of dissipative continuous mechanical systems are studied. A detailed analysis allowed us to detect the already known classical scenarios of transition from periodic to chaotic dynamics, and in particular the Feigenbaum scenario. The Feigenbaum constant was computed for all continuous mechanical objects studied in the first part of the paper. In addition, we illustrate and discuss different and novel scenarios of transition of the analysed systems from regular to chaotic dynamics, and we show that the type of scenario depends essentially on excitation parameters.

CORPORATE GOVERNANCE IN INDIA: AN ANALYSIS

Directory of Open Access Journals (Sweden)

Meghna Thapar

2017-03-01

Full Text Available Corporate governance is a process, relation and mechanism set up for the corporations and firms based on certain guidelines and principles by which a company is controlled and directed. The principles provided in the system ensure that the company is governed in a way that it is able to set and achieve its goals and objectives in the context of the social, regulatory and market environment, and is able to maximize profits and also benefit those whose interest is involved in it, in the long run. The division and distribution of rights and responsibilities among different participants in the corporation (such as the board of directors, managers, shareholders, creditors, auditors, regulators, and other stakeholders and inclusion of the rules and procedures for making decisions in corporate affairs are identified with the help of Corporate Governance mechanism and guidelines. The need to make corporate governance in India transparent was felt after the high profile corporate governance failure scams like the stock market scam, the UTI scam, Ketan Parikh scam, Satyam scam, which were severely criticized by the shareholders. Thus, Corporate Governance is not just company administration but more than that and includes monitoring the actions, policies, practices, and decisions of corporations, their agents, and affected stakeholders thereby ensuring fair, efficient and transparent functioning of the corporate management system. By this paper, the authors intend to examine the concept of corporate governance in India with regard to the provisions of corporate governance under the Companies Act 2013. The paper will highlight the importance and need of corporate governance in India. We will also discuss the important case laws which contributed immensely in the emergence of corporate governance in India.

Dynamics of mathematical models in biology bringing mathematics to life

CERN Document Server

Zazzu, Valeria; Guarracino, Mario

2016-01-01

This volume focuses on contributions from both the mathematics and life science community surrounding the concepts of time and dynamicity of nature, two significant elements which are often overlooked in modeling process to avoid exponential computations. The book is divided into three distinct parts: dynamics of genomes and genetic variation, dynamics of motifs, and dynamics of biological networks. Chapters included in dynamics of genomes and genetic variation analyze the molecular mechanisms and evolutionary processes that shape the structure and function of genomes and those that govern genome dynamics. The dynamics of motifs portion of the volume provides an overview of current methods for motif searching in DNA, RNA and proteins, a key process to discover emergent properties of cells, tissues, and organisms. The part devoted to the dynamics of biological networks covers networks aptly discusses networks in complex biological functions and activities that interpret processes in cells. Moreover, chapters i...

Coexistence of contrasting principles in corporate governance: Two tales of Japanese firms

Directory of Open Access Journals (Sweden)

Taeyoung Yoo

2015-09-01

Full Text Available The underlying logic that shapes the coexistence of contrasting mechanisms in a firm’s governance system remains unclear. We examine the logic that promotes a hybrid form of corporate governance in functional terms. The empirical analysis of Japanese firms shows that a firm’s reliance on capital markets for resource acquisition facilitates its adoption of shareholder-oriented mechanisms, such as committee systems. In contrast, corporate performance is still influenced by some of Japanese society’s characteristic governance mechanisms, such as bank ownership. This finding illustrates that contrasting governance mechanisms coexist in a given system owing to their respective or interacting contributions to corporate performance.

Corporate governance : What’s special about banks?

NARCIS (Netherlands)

Laeven, L.

2013-01-01

This review surveys the literature on the corporate governance of banks. Traditional corporate governance mechanisms, such as concentrated ownership and takeover threats, in principle, also apply to banks. However, banks have special traits and are heavily regulated, preventing natural forms of

Interdisciplinary Research to Elucidate Mechanisms Governing Silver Nanoparticle Fate and Transport in Porous Media

Science.gov (United States)

Pennell, K. D.; Mittleman, A.; Taghavy, A.; Fortner, J.; Lantagne, D.; Abriola, L. M.

2015-12-01

Interdisciplinary Research to Elucidate Mechanisms Governing Silver Nanoparticle Fate and Transport in Porous Media Anjuliee M. Mittelman, Amir Taghavy, Yonggang Wang, John D. Fortner, Daniele S. Lantagne, Linda M. Abriola and Kurt D. Pennell* Detailed knowledge of the processes governing nanoparticle transport and reactivity in porous media is essential for accurate predictions of environmental fate, water and wastewater treatment system performance, and assessment of potential risks to ecosystems and water supplies. To address these issues, an interdisciplinary research team combined experimental and mathematical modeling studies to investigate the mobility, dissolution, and aging of silver nanoparticles (nAg) in representative aquifer materials and ceramic filters. Results of one-dimensional column studies, conducted with water-saturated sands maintained at pH 4 or 7 and three levels of dissolved oxygen (DO), revealed that fraction of silver mass eluted as Ag+ increased with increasing DO level, and that the dissolution of attached nAg decreased over time as a result of surface oxidation. A hybrid Eulerain-Lagragian nanoparticle transport model, which incorporates DO-dependent dissolution kinetics and particle aging, was able to accurately simulate nAg mobility and Ag+ release measured in the column experiments. Model sensitivity analysis indicated that as the flow velocity and particle size decrease, nAg dissolution and Ag+ transport processes increasingly govern silver mobility. Consistent results were obtained in studies of ceramic water filters treated with nAg, where silver elution was shown to be governed by nAg dissolution to form Ag+ and subsequent cation exchange reactions. Recent studies explored the effects of surface coating aging on nAg aggregation, mobility and dissolution. Following ultraviolet light, nAg retention in water saturated sand increased by 25-50%, while up to 50% of the applied mass eluted as Ag+ compared to less than 1% for un-aged n

Adapting adaptation: the English eco-town initiative as governance process

Directory of Open Access Journals (Sweden)

Daniel Tomozeiu

2014-06-01

Full Text Available Climate change adaptation and mitigation have become key policy drivers in the UK under its Climate Change Act of 2008. At the same time, urbanization has been high on the agenda, given the pressing need for substantial additional housing, particularly in southeast England. These twin policy objectives were brought together in the UK government's 'eco-town' initiative for England launched in 2007, which has since resulted in four eco-town projects currently under development. We critically analyze the eco-town initiative's policy evolution and early planning phase from a multilevel governance perspective by focusing on the following two interrelated aspects: (1 the evolving governance structures and resulting dynamics arising from the development of the eco-town initiative at UK governmental level, and the subsequent partial devolution to local stakeholders, including local authorities and nongovernmental actors, under the new 'localism' agenda; and (2 the effect of these governance dynamics on the conceptual and practical approach to adaptation through the emerging eco-town projects. As such, we problematize the impact of multilevel governance relations, and competing governance strategies and leadership, on shaping eco-town and related adaptation strategies and practice.

Basic Coandă MAV Fluid Dynamics and Flight Mechanics

Science.gov (United States)

Djojodihardjo, H.; Ahmed, RI

2017-04-01

Capitalizing on the basic fundamental principles, the Fluid Dynamics and Flight Mechanics of a semi-spherical Coandă MAV configurations are revisited and analyzed as a baseline. A mathematical model for a spherical Coandă MAV in hover and translatory motion is developed and analyzed from first physical principles. To gain further insight into the prevailing flow field around a Coandă MAV, as well as to verify the theoretical prediction presented in the work, a computational fluid dynamic CFD simulations for a Coandă MAV generic model are elaborated. The mathematical model and derived performance measures are shown to be capable in describing the physical phenomena of the flow field of the semi-spherical Coandă MAV. The relationships between the relevant parameters of the mathematical model of the Coandă MAV to the forces acting on it are elaborated subsequently.

Trends in nanoscale mechanics mechanics of carbon nanotubes, graphene, nanocomposites and molecular dynamics

CERN Document Server

2014-01-01

This book contains a collection of the state-of-the-art reviews written by the leading researchers in the areas of nanoscale mechanics, molecular dynamics, nanoscale modeling of nanocomposites and mechanics of carbon nanotubes. No other book has reviews of the recent discoveries such as a nanoscale analog of the Pauli’s principle, i.e., effect of the spatial exclusion of electrons or the SEE effect, a new Registry Matrix Analysis for the nanoscale interfacial sliding and new data on the effective viscosity of interfacial electrons in nanoscale stiction at the interfaces. This volume is also an exceptional resource on the well tested nanoscale modeling of carbon nanotubes and nanocomposites, new nanoscale effects, unique evaluations of the effective thickness of carbon nanotubes under different loads, new data on which size of carbon nanotubes is safer and many other topics. Extensive bibliography concerning all these topics is included along with the lucid short reviews. Numerous illustrations are provided...

Governance mechanisms and the institutional design of the Health Secretariat in the Municipality of Rio de Janeiro (RJ), Brazil.

Science.gov (United States)

Ribeiro, José Mendes; Alcoforado, Flávio

2016-05-01

In this article, we outline the discussions about the mechanisms of governance and public administration taking into account the main political and economic schools of thought which affect the decisions taken by elected and public bodies. We discuss the pendulum-style approach of the reforms and the degree of minimization of the Weberian thesis on rational bureaucracy. Taking into account conceptual aspects and the trajectory of the debate on a new form of public governance and the 1995 State of Brazil reforms, we analyzed the institutional design of the Municipal Health Secretariat in Rio de Janeiro after the reforms were adopted, based on a social organizational model. We also took into account regulatory capacity and the sustainability of the governmental schools.

Dynamic analysis of six-bar mechanical press for deep drawing

Science.gov (United States)

Mitsi, S.; Tsiafis, I.; Bouzakis, K. D.

2017-02-01

This paper analyzes the dynamical behavior of a six-bar linkage used in mechanical presses for metal forming such as deep drawing. In the under study mechanism, a four-bar linkage is connected to a slider through an articulated binary link. The motion of the six-bar linkage is studied by kinematic analysis developing an analytical method. Furthermore, using an iterative method and d’ Alembert’s principle, the joint forces and drive moment are evaluated considering joint frictions. The simulation results obtained with a MATLAB program are validated by comparing the theoretical values of the input moment with the ones obtained from the conservation of energy law.

Corporate Governance in the Swedish Banking Sector

OpenAIRE

Palmberg, Johanna

2010-01-01

This paper studies the corporate governance structure among Swedish banks. Who controls the Swedish banks and what characteristics does the Swedish banking sector have? Issues related to corporate governance such as ownership structure, board of directors and control-enhancing mechanisms will be studied. The Swedish banking law, how Swedish banks handled the financial crises and government measures to deal with the financial crisis is also analyzed.

OPTIMALISASI BANK SYARI’AH MENUJU GOOD CORPORATE GOVERNANCE

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Fahrur Ulum Fahrur Ulum

2013-08-01

Full Text Available Abstract: Syarî’ah banking must be optimized earnestly to fulfill the stakeholders interest. The effective implementation of cooporate governance would realize the goal of fairness, accountability, and transparancy.  There are several prior focus of this system manager: basic concept and problems of cooperate governance in syarî’ah banking, the pillars of implementation, and the mechanism.  As a result, to create an effective  cooperate governance of syariah banking, the following aspects must be urgently required: a contract clarity, market discipline, moral dimension, socio-political atmosphere,  law enforcement, and institution. Board of directors, senior management, stockholders, and depositors have important roles to establish the  harmony of syariah banking development. The stakeholders  are directly connected to the mechanism of cooperate governance of syariah banking. Key Words: corporate governance, bank syari’ah, stakeholders, dan mudlârabah

Performance evaluation on air pollution reducing facilities and mechanism research on the third-party governance on environmental pollution

Science.gov (United States)

Bingsheng, Xu; Ling, Lin; Jin, Huang; Geng, Wang; Jianhua, Chen; Shuo, Yang; Huiting, Guo

2017-11-01

The paper focuses on developing the operational efficiency of air pollution reducing facilities and the treatment effect of the third-party governance on environmental pollution. Comprehensive analysis method and influence factor analysis are employed to build an evaluation index system by means of discussing major pollution control factors derived from the performance of pollution control equipment operation, environmental protection, technological economy, recourse consumption and manufacturing management. Based on the pattern of environmental pollution control offered by the third-party company, the static games model is further established between the government and the pollution emission firm by considering the whole process of the pollution abatement including investment, construction and operation of the treatment project, which focuses on establishing the policy condition and consequence by discussing the cost and benefit in a short and a long time, respectively. The research results can improve the market access requests of the pollution control equipment and normalize the environmental protection service offered by the third-party company. Moreover, the establishment of the evaluation index system for pollution control equipment and the evaluation mechanism for the third-party governance on environmental pollution has guiding significance on leading environmental protection industry and promoting market-oriented development

CIEMAT results in the frame of the european project Mechanisms governing the behaviour and transport of transuranics (analogues) and other radionuclides in marine ecosystems

International Nuclear Information System (INIS)

Gasco, C.; Anton, M.P.

1996-01-01

This report summarises the objectives and more relevant conclusions obtained by CIEMAT in the frame of the project Mechanisms governing the behaviour and transport of transuranics (analogues) and other radionuclides in marine ecosystems. The overall objective of this project was to identify the basic mechanisms and define the key parameters governing the physico-chemical speciation, vertical and horizontal mobility, biological magnification, incorporation to seabed sediments and ultimate fate of transuranium and other long-lived radionuclides in the marine environment, with a view to providing high-quality data of a universal character for use in the development and validation of predictive models based on fundamental mechanisms rather than the simpler box-model approach. This research was carried out in different European marine ecosystems: those directly affected by controlled releases from Nuclear Industries and/or accidents and those characterized by being preferent radionuclides accumulation sites (submarine canyons, estuaries, etc.). (Author)

GOVERNING BOARD OF THE PENSION FUND

CERN Document Server

2001-01-01

The Governing Board of the Pension Fund held its ninety-ninth meeting on 6 March. On that occasion, it examined the assets-liabilities management report presented by Professor Guus E. Boender and Mr H. Steehouwer of the firm ORTEC of Rotterdam. The first part of the presentation of the report consisted of a general introduction to the principles of an assets-liabilities management study, its mechanisms and its goals. Professor Boender particularly underlined the importance of such studies which are based on a probabilistic approach to determine the trend in the long-term financial position of a pension fund in a dynamic context. For bodies responsible for ensuring that the prerequisites for a balanced pension fund exist, the assets-liabilities management study provides the opportunity, on the basis of a large number of financial scenarios, to assess the risks of insufficient asset cover to meet a pension fund's long-term commitments and to identify measures for remedying it. The second part of the presentatio...

Responsibility with accountability: A FAIR governance framework for performance accountability of local governments

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Anwar Shah

2014-12-01

Full Text Available This paper focuses on the role of local governments in bringing about fair, accountable, incoorruptible and responsive (FAIR governance. Local governments around the world have done important innovations to earn the trust of their residents and their comparative performance is of great interest yet a comprehensive framework to provide such benchmarking is not available. This paper attempts to fill this void, by developing a general framework for performance accountability of local governments and by relating real world practices to aspects of this framework. The proposed rating framework requires several types of assessments: (a their compliance with due process and law; (b monitoring of fiscal health for sustainability; (c monitoring of service delivery ; and (d citizens’ satisfaction with local services. The approach yields key indicators useful for benchmarking performance that can be used in selfevaluation and improvement of performance. t From an analysis of practices in local government performance monitoring and evaluation, the paper concludes that ad hoc ad-on self standing monitoring and evaluation systems are more costly and less useful than built-in tools and mechanisms for government transparency, self–evaluation and citizen based accountability such as local government output budgeting and output based fiscal transfers to finance local services.

Dynamic Self-Healing Mechanism for Transactional Business Process

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Yuhai Zhao

2015-01-01

Full Text Available It is clear that transactional behavior consistency is a prerequisite and basis for construction of a reliable services-based business application. However, in previous works, maintaining transactional consistency during exception handling was ignored. Maintaining transactional consistency requires functionality for rolling back some operations and revoking uploaded data. Replacing only the failed service will eventually lead to overall business application failure. In this study, we take fully into account the behavioral consistency of transactional services and propose two effective self-healing mechanisms for service-based applications. If a service enters into potential failure condition, a rescheduling mechanism is triggered to maintain consistent transactional behavior and to ensure reliable execution; if a service fails during execution, the compensation operation is triggered and the system will take action to ensure transactional behavior consistency. Meanwhile, cost-benefit analysis with compensation support is proposed to minimize the dynamic reselection cost. Finally, the experimental analysis shows that the proposed strategies can effectively guarantee the reliability of Web-based applications system.

Rethinking Local Governance: Hierarchies and Networks in Mexican Cities

OpenAIRE

Francisco Porras

2007-01-01

In recent years, the literature of governance has  gained relevance in public administration studies.  One of its main contributions has been to propose  that the use of networks in policy processes, instead of hierarchies, has modified our understanding of contemporary government. Governance  literature has been produced mainly in AngloSaxon countries; nevertheless, this article argues  that it has some value as a tool to explain present  dynamisms in Mexican municipalities. Local  networks ...

Corporate Governance & Auditor Choice in Malaysia

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Wan Nasrudin Wan Asma

2017-01-01

Full Text Available The aim of this paper is to investigate the determinants of firm’s auditor choice in Malaysia in respect of their corporate governance mechanisms. A logit regression model was developed to test the impact of firms’ internal corporate governance mechanism on auditor choice decisions made by public listed companies listed on main board of Bursa Malaysia from year 2006 to 2015. Five variables are used to proxy for firm’s internal corporate mechanism which are the ownership concentration, the duality of CEO and chairman of BOD, the size of audit committee, the size of BOD and the number of independent directors on the board. All auditors in Malaysia were classified into Big Four and non-Big Four, assuming Big Four auditors can provide higher quality audit services. The final result show that firms with less concentrated ownership, with larger size of audit committee, larger size of the BOD, with lower proportion of independent directors on the board, or in which CEO and BOD’s chairman are not the same person are more likely to hire a high-quality auditor. Hence, it suggests that when benefits from lowering capital raising costs are trivial, firms with good corporate governance mechanism are prone to choose a high-quality auditor.

FINANCING DECISION AND CORPORATE GOVERNANCE

OpenAIRE

ANDREI STANCULESCU; DAN NICOLAE IVANESCU; PETRE BREZEANU

2011-01-01

This paper sustains the existence of a biunivocal link between a company’s financing decision and the corporate governance. On the one hand, the financing decision has an impact on corporate performance, which has been confirmed. According to the agency theory, the financing decision will contribute to solving interest conflicts between shareholders and managers. On the other hand, the corporate governance mechanism provides the proper contractual framework for attracting financing resources....

Molecular dynamics simulation of nanocrystalline nickel: structure and mechanical properties

Energy Technology Data Exchange (ETDEWEB)

Swygenhoven, H. van [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Caro, A. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche

1997-09-01

Molecular dynamics computer simulations of low temperature elastic and plastic deformation of Ni nanophase samples (3-7 nm) are performed. The samples are polycrystals nucleated from different seeds, with random locations and orientations. Bulk and Young`s modulus, onset of plastic deformation and mechanism responsible for the plastic behaviour are studied and compared with the behaviour of coarse grained samples. (author) 1 fig., 3 refs.

Molecular dynamics simulation of nanocrystalline nickel: structure and mechanical properties

International Nuclear Information System (INIS)

Swygenhoven, H. van; Caro, A.

1997-01-01

Molecular dynamics computer simulations of low temperature elastic and plastic deformation of Ni nanophase samples (3-7 nm) are performed. The samples are polycrystals nucleated from different seeds, with random locations and orientations. Bulk and Young's modulus, onset of plastic deformation and mechanism responsible for the plastic behaviour are studied and compared with the behaviour of coarse grained samples. (author) 1 fig., 3 refs

THE GLOBAL GOVERNANCE PROBLEM AND THE ROLE OF THE INTERNATIONAL MONETARY FUND

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Sidorova E. A.

2015-06-01

Full Text Available Currently, globalization begins to permeate more and more areas of human activity, therefore it is important question of the complex mechanisms and principles of global governance formation.The article analyzes the essence, subjects and mechanisms for the implementation of the global economic governance. Moreover, it investigates the role and current state of the International Monetary Fund (IMF in the global economy. In conclusion, it clarifies the relationship of the IMF and processes of global governance. Research has shown that it is necessary to create within the IMF more representative, economically and politically balanced system of global governance of the world monetary and financial relations as part of the emerging mechanisms of global economic governance. This article extends the knowledge about the features of the IMF in the forming global governance.

MULTI PERIOD SHOCKS ROLES ON GOVERNMENT SPENDING IN INDONESIA

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Jaka Sriyana

2011-09-01

Full Text Available This paper proposes an alternative dynamic model of government spending in Indonesia. The model is based on short term disequilibrium assumption, in which multi period of shocks variables may play an important role. This research applies a loss function approach and uses optimum shock variables as the determinant for government spending during 1970-2010. The result shows that real GDP, population, and multi period shock of government spending are statistically significant. It provides evidence of the impact of multi period shocks to the realization of government spending. It implies that government faces a serious disequilibrium in determining their spending both in short and long terms.Keywords: Fiscal, government spending, deficit budget, shockJEL classification numbers: H53, H62, C22

Hydrodynamic relaxations in dissipative particle dynamics

Science.gov (United States)

Hansen, J. S.; Greenfield, Michael L.; Dyre, Jeppe C.

2018-01-01

This paper studies the dynamics of relaxation phenomena in the standard dissipative particle dynamics (DPD) model [R. D. Groot and P. B. Warren, J. Chem. Phys. 107, 4423 (1997)]. Using fluctuating hydrodynamics as the framework of the investigation, we focus on the collective transverse and longitudinal dynamics. It is shown that classical hydrodynamic theory predicts the transverse dynamics at relatively low temperatures very well when compared to simulation data; however, the theory predictions are, on the same length scale, less accurate for higher temperatures. The agreement with hydrodynamics depends on the definition of the viscosity, and here we find that the transverse dynamics are independent of the dissipative and random shear force contributions to the stress. For high temperatures, the spectrum for the longitudinal dynamics is dominated by the Brillouin peak for large length scales and the relaxation is therefore governed by sound wave propagation and is athermal. This contrasts the results at lower temperatures and small length scale, where the thermal process is clearly present in the spectra. The DPD model, at least qualitatively, re-captures the underlying hydrodynamical mechanisms, and quantitative agreement is excellent at intermediate temperatures for the transverse dynamics.

Corporate Governance, between Classicism and Modernism

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Niculae Feleaga

2006-07-01

Full Text Available Corporate governance represents a complex concept, being an assembly of mechanisms used to set order into company leaders’ decisions. The rules of corporate governance are the ones keeping the score between the economic entity’s leaders and the third parties who invest their resources in the business. The corporate governance issue did not appear by hazard, but it resulted from the necessity to reconcile many business interests within a company (sometimes contradictory issues, especially the ones between the shareholders and the business leaders. The Anglo-Saxon view, in which the business power is given to the Equity items, is traditionally opposing the European (continental vision, where focus is being made on the Stakeholders’ interests. Within a world dominated by globalization issues, and where the financial markets evolve on an exponential curve, the two above mentioned corporate governance models ought to interact one with another in a constructive manner. Even if the corporate governance concept has developed recently, mainly during the last 25 years, its origins are rooted way back into the world history. Corporate governance is organically linked to the capitalist society and economy. After the 11 September attacks, many of the contemporary authors had the tendency to declare this date as the beginning of the XXIst century. If the ‘Twin Towers’ had hosted companies like: Tyco, Enron, Xerox, Wordcom and many other Stock Exchange-quoted businesses, it is likely that the financial crisis from 2000-2002 would have been differently perceived, and corporate governance had developed slightly different evolutionary mechanisms. A scientific article, based on the comparison between the classical and modern corporate governance experiences, would therefore suit the Romanian business environment.

Corporate Governance, between Classicism and Modernism

Directory of Open Access Journals (Sweden)

Cristina Vasile

2006-09-01

Full Text Available Corporate governance represents a complex concept, being an assembly of mechanisms used to set order into company leaders’ decisions. The rules of corporate governance are the ones keeping the score between the economic entity’s leaders and the third parties who invest their resources in the business. The corporate governance issue did not appear by hazard, but it resulted from the necessity to reconcile many business interests within a company (sometimes contradictory issues, especially the ones between the shareholders and the business leaders. The Anglo-Saxon view, in which the business power is given to the Equity items, is traditionally opposing the European (continental vision, where focus is being made on the Stakeholders’ interests. Within a world dominated by globalization issues, and where the financial markets evolve on an exponential curve, the two above mentioned corporate governance models ought to interact one with another in a constructive manner. Even if the corporate governance concept has developed recently, mainly during the last 25 years, its origins are rooted way back into the world history. Corporate governance is organically linked to the capitalist society and economy. After the 11 September attacks, many of the contemporary authors had the tendency to declare this date as the beginning of the XXIst century. If the ‘Twin Towers’ had hosted companies like: Tyco, Enron, Xerox, Wordcom and many other Stock Exchange-quoted businesses, it is likely that the financial crisis from 2000-2002 would have been differently perceived, and corporate governance had developed slightly different evolutionary mechanisms. A scientific article, based on the comparison between the classical and modern corporate governance experiences, would therefore suit the Romanian business environment.

Understanding global health governance as a complex adaptive system.

Science.gov (United States)

Hill, Peter S

2011-01-01

The transition from international to global health reflects the rapid growth in the numbers and nature of stakeholders in health, as well as the constant change embodied in the process of globalisation itself. This paper argues that global health governance shares the characteristics of complex adaptive systems, with its multiple and diverse players, and their polyvalent and constantly evolving relationships, and rich and dynamic interactions. The sheer quantum of initiatives, the multiple networks through which stakeholders (re)configure their influence, the range of contexts in which development for health is played out - all compound the complexity of this system. This paper maps out the characteristics of complex adaptive systems as they apply to global health governance, linking them to developments in the past two decades, and the multiple responses to these changes. Examining global health governance through the frame of complexity theory offers insight into the current dynamics of governance, and while providing a framework for making meaning of the whole, opens up ways of accessing this complexity through local points of engagement.

A dynamical mechanism for the hairpin diagram

International Nuclear Information System (INIS)

Chang Chaohsi; Guo Xinheng; Li Xueqian.

1989-09-01

Based on the non-valence quark-antiquark and gluon constituent structure of mesons we give a reasonable dynamical mechanism which can induce the hairpin diagram without violating the well-observed OZI rule. We calculate the hairpin amplitudes of D deg. → K-bar deg.η and K-bar deg.η' normalized by D deg. → K-bar deg.π deg. and have found that the hairpin diagram can give rise to substantial contribution to the decays where a meson with a SU(3) flavor singlet component is involved in the final state. In this scenario, we also obtain the branching ratio of D deg. → K-bar deg. φ as 0.55% in comparison with the experimental data of 0.83%. (autor). 33 refs, 3 figs

Practical application of corporate governance principles in a developing country: A case study

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Wanjiru Gachie

2017-03-01

Full Text Available The importance of examining corporate governance in organisations cannot be overemphasised. Corporate governance failure which has resulted from weak corporate governance systems has highlighted the need for research aimed at contributing to the improvement and reform of corporate governance at business, national and international level. A review of corporate governance mechanisms and their practical application in two retail companies in South Africa was undertaken. The research question that informed the study was: What is the nature of corporate governance mechanisms in the South African retail sector? The research design entailed analysis of secondary data, namely Annual Reports and other pertinent documents, and document analysis was used to show what is accessible to the ordinary share/stake-holder and what is not. Data analysis was conducted both qualitatively and quantitatively. With regard to corporate governance mechanisms, the results and discussion show that the two companies have not yet complied with the King II and III codes. Recommended strategies to strengthen corporate governance mechanisms in the South African retail sector should include a commitment to risk disclosure and revamping of the corporate governance structure of the ‘whole’ system.

PENGARUH INTERDEPENDENSI MEKANISME CORPORATE GOVERNANCE TERHADAP KINERJA PERBANKAN

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Ali Muktiyanto

2011-12-01

Full Text Available This study aims to examine the effect of interdependence mechanisms of corporate governance on company performance (Agrawal and Knoeber 1996. These mechanisms are: managerial ownership, institutional ownership, independent commissioner, board size, debt policy, dividend policy, market concentration, and market share with the control variables are growth, size, and firm ages. Test results on 349 firm-years using OLS regression for each mechanism and 2SLS regression for simultaneous testing indicate the presence of interdependence between the mechanisms. both parsial and simultanously; managerial ownership and dividend policy does not significantly influence on the banking efficiency. Significant positive effect of the board size and institutional ownership when tested by OLS did not recur when tested simultaneously using 2SLS. Instead, the independent commissioner when tested by 2SLS have significant negative effect but using OLS no significant effect. There are three variables of corporate governance mechanisms have consistent effect on the banking efficiency; debt policy has significant negative effect, while the market concentration and market share have significant positive effect. Different results between the tests using OLS and 2SLS emphasize the interdependence of these mechanisms is also shown that application of the policy of corporate governance mechanisms should be done carefully so that the expected performance can be achieved.

Predictive Modeling of Mechanical Properties of Welded Joints Based on Dynamic Fuzzy RBF Neural Network

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ZHANG Yongzhi

2016-10-01

Full Text Available A dynamic fuzzy RBF neural network model was built to predict the mechanical properties of welded joints, and the purpose of the model was to overcome the shortcomings of static neural networks including structural identification, dynamic sample training and learning algorithm. The structure and parameters of the model are no longer head of default, dynamic adaptive adjustment in the training, suitable for dynamic sample data for learning, learning algorithm introduces hierarchical learning and fuzzy rule pruning strategy, to accelerate the training speed of model and make the model more compact. Simulation of the model was carried out by using three kinds of thickness and different process TC4 titanium alloy TIG welding test data. The results show that the model has higher prediction accuracy, which is suitable for predicting the mechanical properties of welded joints, and has opened up a new way for the on-line control of the welding process.

The PTFE-nanocomposites mechanical properties for transport systems dynamic sealing devices elements

Science.gov (United States)

Mashkov, Y. K.; Egorova, V. A.; Chemisenko, O. V.; Maliy, O. V.

2017-06-01

The mechanical properties study results of polymer nanocomposites based on polytetrafluoroethylene with modifiers in the form of micro- and nanoscale cryptocrystalline graphite and silicon dioxide powders are determined. The nanocomposites mechanical properties determined values provide high sealing degree of transport systems dynamic sealing devices elements. When the temperature changes from cryogenic to high positive then the elastic modulus, tensile strength decrease significantly and nonlinearly, the latter limits the composite usage in heavily loaded tribosystems operating at elevated temperatures.

Neocortical dynamics at multiple scales: EEG standing waves, statistical mechanics, and physical analogs.

Science.gov (United States)

Ingber, Lester; Nunez, Paul L

2011-02-01

The dynamic behavior of scalp potentials (EEG) is apparently due to some combination of global and local processes with important top-down and bottom-up interactions across spatial scales. In treating global mechanisms, we stress the importance of myelinated axon propagation delays and periodic boundary conditions in the cortical-white matter system, which is topologically close to a spherical shell. By contrast, the proposed local mechanisms are multiscale interactions between cortical columns via short-ranged non-myelinated fibers. A mechanical model consisting of a stretched string with attached nonlinear springs demonstrates the general idea. The string produces standing waves analogous to large-scale coherent EEG observed in some brain states. The attached springs are analogous to the smaller (mesoscopic) scale columnar dynamics. Generally, we expect string displacement and EEG at all scales to result from both global and local phenomena. A statistical mechanics of neocortical interactions (SMNI) calculates oscillatory behavior consistent with typical EEG, within columns, between neighboring columns via short-ranged non-myelinated fibers, across cortical regions via myelinated fibers, and also derives a string equation consistent with the global EEG model. Copyright © 2010 Elsevier Inc. All rights reserved.

Industry Evidence on the Effects of Government Spending

OpenAIRE

Christopher J. Nekarda; Valerie A. Ramey

2010-01-01

This paper investigates industry-level effects of government purchases in order to shed light on the transmission mechanism for government spending on the aggregate economy. We begin by highlighting the different theoretical predictions concerning the effects of government spending on industry labor market equilibrium. We then create a panel data set that matches output and labor variables to shifts in industry-specific government demand. The empirical results indicate that increases in gover...

Understanding the differing governance of EU emissions trading and renewable: feedback mechanisms and policy entrepreneurs

Energy Technology Data Exchange (ETDEWEB)

Boasson, Elin Lerum; Wettestad, Joergen

2010-04-15

This paper presents a comparative study of two central EU climate policies: the revised Emissions Trading System (ETS), and the revised Renewable Energy Directive (RES). Both were originally developed in the early 2000s and revised policies were adopted in December 2008. While the ETS from 2013 on will have a quite centralized and market-streamlined design, the revised RES stands forward as a more decentralized and technology-focused policy. Differing institutional feed-back mechanisms and related roles of policy entrepreneurs can shed considerable light on these policy differences. Due to member states' cautiousness and contrary to the preferences of the Commission, the initial ETS was designed as a rather decentralized and 'politicized' market system, creating a malfunctioning institutional dynamic. In the revision process, the Commission skillfully highlighted this ineffective dynamic to win support for a much more centralized and market-streamlined approach. In the case of RES, national technology-specific support schemes and the strong links between the renewable industry and member states promoted the converse outcome: decentralization and technology development. Members of the European Parliament utilized these mechanisms through policy networking, while the Commission successfully used developments within the global climate regime to induce some degree of centralization. (Author)

Project governance: "Schools of thought"

Directory of Open Access Journals (Sweden)

Michiel Christiaan Bekker

2014-02-01

Full Text Available The terminology, definition and context of project governance have become a focal subject for research and discussions in project management literature. This article reviews literature on the subject of project governance and categorise the arguments into three schools of thought namely the single-firm school, multi-firm school and large capital school. The single-firm school is concerned with governance principles related to internal organisational projects and practice these principles at a technical level. The multi-firm school address the governance principles concerned with two of more organisations participating on a contractual basis on the same project and focus their governance efforts at the technical and strategic level. The large capital school consider projects as temporary organisations, forming their own entity and establishing governance principles at an institutional level. From these schools of thought it can be concluded that the definition of project governance is dependent on the type of project and hierarchical positioning in the organisation. It is also evident that further research is required to incorporate other governance variables and mechanisms such as transaction theory, social networks and agency theory. The development of project governance frameworks should also consider the complexity of projects spanning across international companies, across country borders and incorporating different value systems, legal systems, corporate governance guidelines, religions and business practices.

Computational modeling of lava domes using particle dynamics to investigate the effect of conduit flow mechanics on flow patterns

Science.gov (United States)

Husain, Taha Murtuza

Large (1--4 x 106 m3) to major (> 4 x 106 m3) dome collapses for andesitic lava domes such as Soufriere Hills Volcano, Montserrat are observed for elevated magma discharge rates (6--13 m3/s). The gas rich magma pulses lead to pressure build up in the lava dome that result in structural failure of the over steepened canyon-like walls which may lead to rockfall or pyroclastic flow. This indicates that dome collapse intimately related to magma extrusion rate. Variation in magma extrusion rate for open-system magma chambers is observed to follow alternating periods of high and low activity. Periodic behavior of magma exhibits a rich diversity in the nature of its eruptive history due to variation in magma chamber size, total crystal content, linear crystal growth rate and magma replenishment rate. Distinguished patterns of growth were observed at different magma flow rates ranging from endogenous to exogenous dome growth for magma with varying strengths. Determining the key parameters that control the transition in flow pattern of the magma during its lava dome building eruption is the main focus. This dissertation examines the mechanical effects on the morphology of the evolving lava dome on the extrusion of magma from a central vent using a 2D particle dynamics model. The particle dynamics model is coupled with a conduit flow model that incorporates the kinetics of crystallization and rheological stiffening to investigate important mechanisms during lava dome building eruptions. Chapter I of this dissertation explores lava dome growth and failure mechanics using a two-dimensional particle-dynamics model. The model follows the evolution of fractured lava, with solidification driven by degassing induced crystallization of magma. The particle-dynamics model emulates the natural development of dome growth and rearrangement of the lava dome which is difficult in mesh-based analyses due to mesh entanglement effects. The deformable talus evolves naturally as a frictional

Comparative Corporate Governance of Non-Profit Organizations

DEFF Research Database (Denmark)

Thomsen, Steen

2014-01-01

Based on the impressive work of Hopt and von Hippel (2010), I review the comparative corporate governance of non-profit organizations and propose topics for future research. There is evidence of agency problems in non-profit as well as for-profit organizations, but the governance mechanisms...

Improving Shareholder Value through Corporate Governance Mechanism in Malaysian Listed Companies

OpenAIRE

Ibrahim, Mohammed Yussoff; Ahmad, Ayoib Che; Khan, Muhammad Anees

2016-01-01

This paper proposes to investigate the postulations of renowned agency theory and shareholder value (SHV) in relation to Corporate Governance (CG) attributes. Shareholder value is of a great concern to the shareholders of firms. Shareholder value have been investigated by numerous studies of corporate governance but with inconsistent empirical evidence. This study will focus on investigating the impact of CG attributes on Shareholder value measured by Tobin’s Q or return on both equity and as...

Multivariable Dynamic Ankle Mechanical Impedance With Active Muscles

Science.gov (United States)

Lee, Hyunglae; Krebs, Hermano Igo; Hogan, Neville

2015-01-01

Multivariable dynamic ankle mechanical impedance in two coupled degrees-of-freedom (DOFs) was quantified when muscles were active. Measurements were performed at five different target activation levels of tibialis anterior and soleus, from 10% to 30% of maximum voluntary contraction (MVC) with increments of 5% MVC. Interestingly, several ankle behaviors characterized in our previous study of the relaxed ankle were observed with muscles active: ankle mechanical impedance in joint coordinates showed responses largely consistent with a second-order system consisting of inertia, viscosity, and stiffness; stiffness was greater in the sagittal plane than in the frontal plane at all activation conditions for all subjects; and the coupling between dorsiflexion–plantarflexion and inversion–eversion was small—the two DOF measurements were well explained by a strictly diagonal impedance matrix. In general, ankle stiffness increased linearly with muscle activation in all directions in the 2-D space formed by the sagittal and frontal planes, but more in the sagittal than in the frontal plane, resulting in an accentuated “peanut shape.” This characterization of young healthy subjects’ ankle mechanical impedance with active muscles will serve as a baseline to investigate pathophysiological ankle behaviors of biomechanically and/or neurologically impaired patients. PMID:25203497

New governance in education and dynamics for improvement: pressure versus commitment

OpenAIRE

Antonio Bolívar

2015-01-01

The article defends the thesis that, in the second modernity, we are facing new post-bureaucratic ways of education governance to achieve improvements. The so-called "educational restructuring" assumes, in fact, a new "governance" of education, which includes - among others - deregulation, commercialization and introduction of management principles of business scope. Are analyzed two routes of developing to generate improvement: one that favors competition, using commercial image as regulatin...

Switching among graphic patterns is governed by oscillatory coordination dynamics: Implications for understanding handwriting.

Directory of Open Access Journals (Sweden)

Pier-Giorgio eZanone

2013-09-01

Full Text Available Revisiting an original idea by Hollerbach (1981, previous work has established that the production of graphic shapes, assumed to be the blueprint for handwriting, is governed by the dynamics of orthogonal non-linear coupled oscillators. Such dynamics determines few stable coordination patterns, giving rise to a limited set of preferred graphic shapes, namely, four lines and four ellipsoids independent of orientation. The present study investigates the rules of switching among such graphic coordination patterns. Seven participants were required to voluntarily switch within twelve pairs of shapes presented on a graphic tablet. In line with previous theoretical and experimental work on bimanual coordination, results corroborated our hypothesis that the relative stability of the produced coordination patterns determines the time needed for switching: the transition to a more stable pattern was shorter, and inversely. Moreover, switching between patterns with the same orientation but different eccentricities was faster than with a change in orientation. Nonetheless, the switching time covaried strictly with the change in relative phase effected by the transition between two shapes, whether this implied a change in eccentricity or in orientation. These findings suggest a new operational definition of what the (motor units or strokes of handwriting are and shed a novel light on how co-articulation and recruitment of degrees of freedom may occur in graphic skills. They also yield some leads for understanding the acquisition and the neural underpinnings of handwriting.

Social innovations in local government : The case of local development agent

NARCIS (Netherlands)

Junjan, Veronica; Balogh, Marton

2013-01-01

Background: There is an increased attention in the administrative reform literature accorded to the mechanisms governing the processes of institutionalisation of changes and of diffusion of innovations in local governments. Objectives: Current paper investigates mechanisms that influence the process

Territorial Governance. A Comparative Research of Local Agro-Food Systems in Mexico

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Gerardo Torres-Salcido

2018-01-01

Full Text Available The article attempts to provide a theoretical discussion on territorial governance by presenting both the neo-institutionalist position and the De Sousa Santos’ alternative models, with a view of highlighting the dimensions that can be relevant to understanding the territorial dynamics of Local Agro-food Systems (LAFS. The paper aims to build up a system of indicators, structured in four dimensions, concerning the territorial governance of LAFS: (i multi-level coordination; (ii democratic participation and accountability; (iii cooperation among producers and other stakeholders and (iv relationships with the environment. We verify, as a hypothesis, that the typology of markets to which the identity-based products are directed plays a decisive role in the way that processes of territorial governance of LAFS are constructed. The results of an empirical research, developed in four LAFS in Mexico, are presented: prickly pear cactus in Morelos, blackberry in Michoacán, cuitlacoche (corn smut in Tlaxcala and coffee in Veracruz. Two types of territorial governance of LAFS may be distinguished: those that can be strengthened by the geographical and organisational proximity of the markets and the action of local stakeholders and governments—prickly pear cactus and cuitlacoche—versus those which are devoted to export and are conducted by large companies in which marketing networks involve certification mechanisms and a large number of institutions—coffee and blackberry.

Governance of public health: Norway in a Nordic context.