Irreversible Forces Research Articles

Photoredox Cascade Catalysts for Solar Hydrogen Production from Sustainable Hydrogen Sources.

Visible-light-driven photocatalytic hydrogen (H2) production has been extensively studied as a clean and sustainable energy resource. Although sacrificial electron donors (SEDs) are commonly used to evaluate photocatalytic activity, their irreversible decomposition forces charge separation, which disrupts the inherent dual productivity of photocatalysis, that is, the formation of both the reduction and oxidation products. To achieve highly efficient photoinduced charge separation without SED decomposition, the layer-by-layer assembly of redox-active photosensitizing dyes and electron mediators through Zr4+-phosphonate bonds has been extensively studied as an artificial mimic of the electron transport chain in natural photosynthesis. This concept paper presents an overview of photoredox cascade catalytic (PRCC) systems comprising multiple Ru(II)-trisbipyridine-type dyes and mediator layers on Pt-loaded TiO2 nanoparticles for H2 production from redox reversible electron donors (RREDs). The PRCC structure-activity relationship for photocatalytic H2 production is briefly discussed in terms of layer thickness, surface structure and modification, and cooperativity with molecular oxidation catalysts. Finally, new insights into the design of efficient dual-production photocatalysts based on the PRCC structure are presented.

Max Weber and Walter Benjamin: Politics facing Capitalism

Abstract: The article compares the relationship between capitalism and politics in Max Weber’s and Walter Benjamin’s works. Benjamin’s text Kapitalismus als Religion references Weber’s Die protestantische Ethik und der ‘Geist’ des Kapitalismus . In recent decades, a considerable number of studies have focused on highlighting the differences and affinities between the thinking of Weber and Benjamin. In contrast, this article takes a rarely pursued approach by introducing an overarching point of reference which examines Weber’s and Benjamin’s views on politics. The article asks what potentialities politics has for Weber and Benjamin given the conditions that capitalism imposes. In order to pursue this question, we need to analyse not only Weber’s Protestant Ethic but also some earlier writings that are indicative of the relationship between capitalism and politics: Weber’s Argentinische Kolonistenwirthschaften , Die Börse. I. Zweck und äußere Organisation der Börsen , and Die Börse. II. Der Börsenverkehr ; and Benjamin’s Theologisch-politisches Fragment and Zur Kritik der Gewalt . My argument is that there is a common ground between Weber and Benjamin on politics since both contribute to the idea that the analysis of modern politics must consider the transformations in capitalism. For Weber, political action can provide meaning to the world, in a context of dispute and in a tragic plot of irreversible forces. For Benjamin, politics refers to the possibility of interrupting the course of history, characterised by the persistence of myth that must be overcome.

Globalisation must work for as many regions as possible

ABSTRACT Advanced economies have started to engage more pro-actively in designing, promoting and implementing a range of policies that aim to address the concurrence of two powerful and irreversible forces: one is the urgency of addressing societal and existential threats (including income inequality, joblessness, deindustrialisation, climate change, health and aging), and the other is the disruptive unfolding of new technologies (4.0 technologies). Responding to these challenges marks a pivotal moment for the global economy which will impact on places and with their firms, labour, citizens and the natural environment. This exchange paper advocates for a more meaningful continuum between the global, national and regional scales in a multipolar world.

Landscape-Flux Framework for Nonequilibrium Dynamics and Thermodynamics of Open Hamiltonian Systems Coupled to Multiple Heat Baths.

We establish a nonequilibrium dynamic and thermodynamic formalism in the landscape-flux framework for open Hamiltonian systems in contact with multiple heat baths governed by stochastic dynamics. To systematically characterize nonequilibrium steady states, the nonequilibrium trinity construct is developed, which consists of detailed balance breaking, nonequilibrium potential landscape, and irreversible probability flux. We demonstrate that the temperature difference of the heat baths is the physical origin of detailed balance breaking, which generates the nonequilibrium potential landscape characterizing the nonequilibrium statistics and creates the irreversible probability flux signifying time irreversibility, with the latter two aspects closely connected. It is shown that the stochastic dynamics of the system can be formulated in the landscape-flux form, where the reversible force drives the conservative Hamiltonian dynamics, the irreversible force consisting of a landscape gradient force and an irreversible flux force drives the dissipative dynamics, and the stochastic force adds random fluctuations to the dynamics. The possible connection of the nonequilibrium trinity construct to nonequilibrium phase transitions is also suggested. A set of nonequilibrium thermodynamic equations, applicable to both nonequilibrium steady states and transient relaxation processes, is constructed. We find that an additional thermodynamic quantity, named the mixing entropy production rate, enters the nonequilibrium thermodynamic equations. It arises from the interplay between detailed balance breaking and transient relaxation, and it also relies on the conservative dynamics. At the nonequilibrium steady state, the heat flow, entropy flow, and entropy production are demonstrated to be thermodynamic manifestations of the nonequilibrium trinity construct. The general nonequilibrium formalism is applied to a class of solvable systems consisting of coupled harmonic oscillators. A more specific example of two harmonic oscillators coupled to two heat baths is worked out in detail. The example may facilitate connection with experiments.

Prediction of compression force evolution over degradation for a lithium-ion battery

This study proposes a method to predict the evolution of compression force during the degradation of a lithium-ion battery under packed conditions. The total compression force comprises irreversible and reversible forces. The former is estimated using a multivariate machine learning method, whereas the latter is estimated by combining machine learning and phenomenological modeling. For predicting the irreversible force, impedance-related features are extracted and their correlations with the evolution of the irreversible force are quantitatively analyzed using Grey relational analysis. Subsequently, features with high Grey relational grades are employed as representative health indicators for multivariate inputs of Gaussian process regression. For predicting the reversible force, the force evolution during the charge/discharge period is predicted using a phenomenological force model. The equivalent stiffness used in this model is separately estimated depending on the state of charge (SOC) to account for the inherent characteristics of phase transition and different degradation behaviors. The evolution of equivalent stiffness under high SOC shows nonlinearity but weak evolution characteristics, whereas those under low and medium SOCs show linearity but strong evolution characteristics. Finally, the proposed method is used to enable control and design for two potential applications: estimations of the state of health-dependent SOC and separator compression.

CHALLENGES OF HRM IN A GLOBAL BUSINESS ENVIRONMENT: A REVIEW AND RESEARCH AGENDA

This paper explores the various challenges of HRM and its practice in a global busi-ness environment. The roles and responsibilities of HR departments are transforming as the modern business faces pressures of globalization, hyper-competition in the markets, declining margins and changing consumer demands, workforce diversity, technological advances and changes in the political and legal environment. Today, global HR management has become a front-and-center issue for a wide variety of firms. Many larger corporations, and even smaller ones doing business in key interna-tional markets, now have full-time HR managers devoted solely to assisting with the globalization process. For the HR managers to thrive and be relevant in the global context, new roles and agenda for the profession should not focus on traditional HR activities such as recruitment and selection, training and development, and compensa-tion, but on its outcomes. There is presently an increasing interaction of national eco-nomic systems all over the world through the growth in international trade, invest-ment, and capital flows. This interaction is a worldwide drive toward globalization and a globalized economic system. Globalization, an inevitable and irreversible force is a new reality in which HR practitioners, enterprises and government are always on the lookout for new processes and innovations. This globalization process, therefore, necessitates an investigation into human resource management. The paper utilizes the methods of descriptive analysis and synthesis of the scientific literature and empirical investigation. The paper sums up with requisite conclusion and recommendations that will help HR professionals contribute positively to employees’ well-being and meeting organizational targets in a global business environment

Boundary conditions derived from a microscopic theory of hydrodynamics near solids.

The theory of nonlocal isothermal hydrodynamics near a solid object derived microscopically in the study by Camargo et al. [J. Chem. Phys. 148, 064107 (2018)] is considered under the conditions that the flow fields are of macroscopic character. We show that in the limit of macroscopic flows, a simple pillbox argument implies that the reversible and irreversible forces that the solid exerts on the fluid can be represented in terms of boundary conditions. In this way, boundary conditions are derived from the underlying microscopic dynamics of the fluid-solid system. These boundary conditions are the impenetrability condition and the Navier slip boundary condition. The Green-Kubo transport coefficients associated with the irreversible forces that the solid exert on the fluid appear naturally in the slip length. The microscopic expression for the slip length thus obtained is shown to coincide with the one provided originally by Bocquet and Barrat [Phys. Rev. E 49, 3079 (1994)].

Nanoscale hydrodynamics near solids.

Density Functional Theory (DFT) is a successful and well-established theory for the study of the structure of simple and complex fluids at equilibrium. The theory has been generalized to dynamical situations when the underlying dynamics is diffusive as in, for example, colloidal systems. However, there is no such a clear foundation for Dynamic DFT (DDFT) for the case of simple fluids in contact with solid walls. In this work, we derive DDFT for simple fluids by including not only the mass density field but also the momentum density field of the fluid. The standard projection operator method based on the Kawasaki-Gunton operator is used for deriving the equations for the average value of these fields. The solid is described as featureless under the assumption that all the internal degrees of freedom of the solid relax much faster than those of the fluid (solid elasticity is irrelevant). The fluid moves according to a set of non-local hydrodynamic equations that include explicitly the forces due to the solid. These forces are of two types, reversible forces emerging from the free energy density functional, and accounting for impenetrability of the solid, and irreversible forces that involve the velocity of both the fluid and the solid. These forces are localized in the vicinity of the solid surface. The resulting hydrodynamic equations should allow one to study dynamical regimes of simple fluids in contact with solid objects in isothermal situations.

Conservation laws and path-independent integrals in mechanical-diffusion-electrochemical reaction coupling system

In this study, the conservation laws οf dissipative mechanical-diffusion-electrochemical reaction system are systematically obtained based on Noether's theorem. According to linear, irreversible thermodynamics, dissipative phenomena can be described by an irreversible force and an irreversible flow. Additionally, the Lagrange function, L and the generalized Hamilton least-action principle are proposed to be used to obtain the conservation integrals. A group of these integrals, including the J-, M-, and L-integrals, can be then obtained using the classical Noether approach for dissipative processes. The relation between the J-integral and the energy release rate is illustrated. The path-independence of the J-integral is then proven. The J-integral, derived based on Noether's theorem, is a line integral, contrary to the propositions of existing published works that describe it both as a line and an area integral. Herein, we prove that the outcomes are identical, and identify the physical meaning of the area integral, a concept that was not explained previously. To show that the J-integral can dominate the distribution of the corresponding field quantities, an example of a partial, stress-diffusion coupling process is disscussed.

Numerical simulation of the deterministic vector separation of particles flowing over slanted open cavities

Within the past decade, the separation of particles via continuous flow through microfluidic devices has been developed largely through an Edisonian approach whereby devices have been developed based on observation and intuition. This is particularly true in the development of vector chromatography at vanishingly small Reynolds number for non-Brownian particles. Note that this latter phenomenon has its origins in the irreversible forces that are at work in the device, since Stokes flow reversibility typically prohibits their function otherwise. We present a numerical simulation of the vector separation of non-Brownian particles of different sizes and deformabilities in the Stokes flow through channels whose lower surface is composed of slanted cavities. The simulations are designed to understand the physical principles behind the separation as well as to provide design criteria for devices for separating particles in a given size and flexibility range. The numerical simulations are Stokes flow boundary element simulations using techniques defined elsewhere in the literature, but including a close-range repulsive force between the particles and the slanted cavities. We demonstrate that over a range of repulsive force that is comparable to the roughness in the experimental devices, the separation data (particularly in particle size) are predicted quantitatively and are a very weak function of the range of the force. We then vary the geometric parameters of the simulated devices to demonstrate the sensitivity of the separation efficiency to these parameters, thus making design predictions as to which devices are appropriate for separating particles in different size, shape, and deformability ranges.13 MoreReceived 18 March 2016DOI:https://doi.org/10.1103/PhysRevFluids.1.084101©2016 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFluid-particle interactionsMicrofluidicsMultiphase flowsFluid Dynamics

Endwall Loss and Mixing Analysis of a High Lift Low Pressure Turbine Cascade

A high lift low pressure turbine (LPT) profile designated L2A is used as a test bed for studying the origin of endwall mixing loss and the role of vortical structures in loss development. It is shown analytically and experimentally that the mixing forces within the endwall wake can be decoupled into either mean flow or turbulent forces and can be further classified as either reversible or irreversible. Among the irreversible forces, mean flow shear is negligible compared to turbulent shear, suggesting that turbulence dissipation is the dominant cause of loss generation. As a result, the mean flow components of the vortical structures do not generate significant mixing losses. Rather than mixing effects, the mean flow of the vortices causes the suction surface boundary layer to separate inside the passage, thereby generating the large low energy regions typical of endwall flows. Losses are generated as the low energy regions mix out. This vortex separation effect is demonstrated with an experiment using a profile fence and pressure surface modification near the endwall. The findings in this paper suggest that profile modifications near the endwall that suppress flow separation may provide loss reductions additive to modifications aimed at weakening vortical structures, such as endwall contouring.

Why enumeration counts

Enumerations of informal settlements undertaken by their own community organizations have become increasingly common. These help urban poor communities to mobilize knowledge about themselves – knowledge that is valuable for their own discussions, that helps develop better relations with local governments. This commentary discusses why it is important for communities to have the right to undertake their own research, and how this can become an irreversible force for stronger negotiations with those who see them as a burden, a blight or a vote bank.

Globalization and human resource development in Nigeria

There is presently an increasing interaction of national economic systems all over the world through the growth in international trade, investment and capital flows. This interaction is a worldwide drive toward globalization and a globalized economic system. Globalization, an inevitable and irreversible force is a new reality in which individuals, enterprises and government are always on the lookout for new processes and innovations. In the creation of innovations not only technology is important, but also people, culture and communication. This globalization process therefore necessitates an investigation into human resource development. The main aim of this paper is to explore the impact of globalization on human resource development in Nigeria in two key areas namely; (a) organizational and workplace learning and (b) technology and knowledge.

Conversion of proteins into biofuels by engineering nitrogen flux

Biofuels are currently produced from carbohydrates and lipids in feedstock. Proteins, in contrast, have not been used to synthesize fuels because of the difficulties of deaminating protein hydrolysates. Here we apply metabolic engineering to generate Escherichia coli that can deaminate protein hydrolysates, enabling the cells to convert proteins to C4 and C5 alcohols at 56% of the theoretical yield. We accomplish this by introducing three exogenous transamination and deamination cycles, which provide an irreversible metabolic force that drives deamination reactions to completion. We show that Saccharomyces cerevisiae, E. coli, Bacillus subtilis and microalgae can be used as protein sources, producing up to 4,035 mg/l of alcohols from biomass containing ∼22 g/l of amino acids. These results show the feasibility of using proteins for biorefineries, for which high-protein microalgae could be used as a feedstock with a possibility of maximizing algal growth and total CO(2) fixation.

A partial equilibrium theory for liquids bonded to immobile solids

In order to obtain consistency with the force balance theory of Young and Laplace, which quantitatively predicts the height of capillary rise from the contact angles of drops on solid surfaces, Gibbs made chemical potentials in interface functions of the integral interface free energies. We cite evidence that equilibrium chemical potentials in one-component systems are identical at interfaces to equilibrium chemical potentials in bulk phases. We evaluate two postulates. (1) Partial free energies of liquids at an interface with a solid are functions of the strength and range of attractive fields outside solid phase boundaries. (2) At equilibrium, the chemical potentials in all interfaces of a one-component liquid equal the chemical potential in its interior when the liquid is bonded to one or more immiscible solids. These postulates yield equations for partial equilibrium (PE) states of drops, films, and liquids. The PE equations yield the same prediction of the height of a meniscus from the contact angle of drops as does Young-Laplace theory and also the same dependence of the volume of capillary condensate on vapor pressure as does the Kelvin equation. But our measurements of the contact angles of water on glass and Teflon and between their close-spaced surfaces contradict the YL supposition that meniscus angles are the same as angles of drops on glass and Teflon surfaces and support the PE postulate that attraction by the external fields of solids, not meniscus curvature, is responsible for capillary rise. We use published data to illustrate the validity of the PE conclusion that divergence or convergence at the saturation pressure of a parent liquid depends on whether or not the attractive field of a solid surface imparts to the liquid more than twice the energy required to create two liquid-vapor interfaces. For divergent water films on quartz, the PE equation provides a quantitative fit to experimental data for films of any thickness greater than 1.5 nm. No previous theory has accomplished that. In an appendix, we illustrate applications of PE theory to evaluating the complex interactions between inherently reversible chemical diffusion and inherently irreversible forces introduced by strains.

Agglomeration of oppositely charged particles in nonpolar liquids

We study the aggregation of insulating electrically charged spheres suspended in a nonpolar liquid. Regarding the van der Waals interaction as an irreversible sticking force, we are especially interested in the charge distribution after aggregation. Solving the special case of two oppositely charged particles exactly, it is shown that the surface charges either recombine or form a residual dipole, depending on the initial condition. The theoretical findings are compared to numerical results from Monte Carlo simulations.

The Future: Globalization and New Roles for HRD

The problem and the solution. Globalization, an inevitable and irreversible force, has significantly affected the workplace and the community, in ways both good and bad. Human resource development's (HRD's) response and impact has been minimal and at a mostly micro level. This article discusses seven key macro areas in which HRD can maximize the beneficial elements of globalization and limit its dehumanizing forces, namely, (a) political development, (b) economic development, (c) organizational and workplace learning, (d) education and vocational training, (e) global leadership development, (f) technology and knowledge, and (g) environment sustainability.

Corporate Renewal Through Cooperation and Critical Technologies

Most financial institutions, and many well-known companies, have not yet fully appreciated profound nature of technology-driven in management strategy now required for industrial competitiveness--even survival. Several basic premises are involved: * Wealth no longer will be measured primarily in terms of ownership of fured physical assets, many of which can be obsolete in a few years. * Alternatively, wealth increasingly will be measured in terms of ownership of (or timely access, through strategic alliances, to) knowledge-intensive, high-value-added, technology-driven systems that are primarily designed to increase productivity. * Current accounting methodologies, consequently, do not adequately reflect true value of either existing business operations or of new business opportunities. The profound nature of this paradigm shift mandates a process of continuous corporate renewal structured specifically to manage continuous change, and to simultaneously involve all elements of management (marketing, production, technology, legal, and financial). This is often called concurrent engineering, task force, or modified matrix management. The need for continuous corporate renewal is driven primarily by rapid emergence of advanced which have collapsed product and process half-lives often to less than five years, making equipment and facilities obsolete long before their useful lives can be reached. Other irreversible forces also are involved: * The communications revolution now allows capital and information to flow with speed of light anywhere in world, with technology rapidly following. * Any in world now can be transformed in less than a year into a state-of-the-art facility operated by $2-an-hour labor, leading to excess capacity worldwide in many industries. * Foreign nation assemble vertically integrated consortia, which, with heavy government subsidies, are designed to capture market share in existing businesses through predatory pricing. The targeting and rice paddy syndromes are zero-sum strategies that carve same pie into smaller pieces, overbuilding world capacity in businesses involved (steel, aluminum, automobiles, semiconductors, etc.) and destroying profitability for everyone. The constructive alternative is one that develops next-generation critical technologies, which will dominate 21st century and which can expand pie and raise quality of life for all nations. CTITICAL TECHNOLOGIES AND CORPORATE RENEWAL Adam Smith pointed out in 1776 that investment creates new wealth, and progress does not have to be a zero-sum game that beggats thy neighbor (1). In 21st century, profitable operation will require not only annual incremental improvements (10 percent to 20 percent per year) in existing businesses (just to maintain cash flows), but also simuEtaneozls investments in next-generation systems deliberately designed to make obsolete current operations before a competitor does, and often before their useful lives can be realized. Fortunately, an historically unprecedented opportunity now exists to implement both of these strategies. This unique situation has resulted from a trillion.dollar investment over last 40 years in U.S. academic infrastructure of universities and government laboratories. Following World War II, Vannevar Bush in his report to President Truman defined research as the endless frontier (2). Creation of National Science Foundation followed, with subsequent buildups in medical research, aerospace and high energy physics, electronics, communications, and material sciences. Today, U.S. spends over $25 billion for basic research, 10 times more than any other nation has in-place capability to match. This unique level of investment has resulted in most of Nobel Prizes, and most of seminal technical discoveries, which are basis of 20-plus critical technologies recently defined by various government agencies (3). …

Irreversible thermodynamics of thermoviscous solids with microstructures

The irreversible thermodynamics of viscous solids with microstructures is developed in a new approach. In this general theory, the ’’particle’’ in the continuous medium is a composite ’’molecule.’’ The field equations describing the motions of the mass points making up the molecule are written down in terms of an internal energy potential U and a dissipation function D. The irreversible mechanical force acting on the mass point is related to D. The conservation laws of momentum, energy, and angular momentum are derived from the spatial invariance properties of U and D, and are thus automatically satisfied. The balance of entropy is a built-in process. The cases of anisotropic liquids and liquid crystals can be developed in a similar fashion.

Information-theoretic stability and evolution criteria in irreversible thermodynamics

Generalized information gains are used to derive stability conditions, for steady states, periodic orbits and invariant sets, and general evolution criteria, both global and local with respect to the time variable, in irreversible thermodynamics. Meixner's passivity condition and the Glansdorff-Prigogine stability and evolution criteria are found to be special cases thereof. The information gain quantities include Kullback's three kinds of divergences, the first two of which are dual to each other and yield criteria which are symmetric in the average densities of the system's extensive variables and the conjugate parameters, but which are nonsymmetric in the irreversible fluxes and forces, while the third one does not involve the entropy function of the system. Furthermore, Renyi's information gain of orderα and Csiszar'sf-divergence are treated. The latter is used to construct a most general information gain quantity as a Liapunov function and evolution criterion, which, however, for local stability and evolution conditions is still equivalent to the use of the second-order variation of the entropy.