Graphite Electrode Modified with a New Phenothiazine Derivative and with Carbon Nanotubes for NADH Electrocatalytic Oxidation

The electrochemical behavior of a modified electrode obtained by immobilization of single-walled carbon nanotubes onto a graphite electrode modified with a new phenothiazine derivative, bis-phenothiazin-3-yl methane (BPhM), G/BPhM-CNT, has been evaluated and compared with BPhM adsorbed on graphite electrode (G/BPhM). The G/BPhM-CNT electrode presents improved performances for NADH electrocatalytic oxidation in comparison with G/BPhM electrode, expressed by: (i) a significant increase of electrocatalytic rate constant (kobs,[NADH] 0) for NADH oxidation (856.32 L mol–1 s–1 for G/BPhM-CNT and 51.63 L mol–1 s–1 for G/BPhM, in phosphate buffer, pH 7); (ii) the obtained amperometric sensors for NADH detection present increase sensitivity (S = 6.9 mA L mol–1 for G/BPhM-CNT and S = 0.55 mA L mol–1 for G/BPhM, pH 7)

Analysis of complex contagions in random multiplex networks

We study the diffusion of influence in random multiplex networks where links can be of $r$ different types, and for a given content (e.g., rumor, product, political view), each link type is associated with a content dependent parameter $c_i$ in $[0,\infty]$ that measures the relative bias type-$i$ links have in spreading this content. In this setting, we propose a linear threshold model of contagion where nodes switch state if their "perceived" proportion of active neighbors exceeds a threshold \tau. Namely, a node connected to $m_i$ active neighbors and $k_i-m_i$ inactive neighbors via type-$i$ links will turn active if $\sum{c_i m_i}/\sum{c_i k_i}$ exceeds its threshold \tau. Under this model, we obtain the condition, probability and expected size of global spreading events. Our results extend the existing work on complex contagions in several directions by i) providing solutions for coupled random networks whose vertices are neither identical nor disjoint, (ii) highlighting the effect of content on the dynamics of complex contagions, and (iii) showing that content-dependent propagation over a multiplex network leads to a subtle relation between the giant vulnerable component of the graph and the global cascade condition that is not seen in the existing models in the literature.Comment: Revised 06/08/12. 11 Pages, 3 figure

A Model for Access Negotiations in Dynamic Coalitions

The process of negotiating common access states in dynamic coalitions that comprise tens of autonomous domains sharing hundreds of resources is time-consuming and error-prone if performed without the benefit of automated tools. This process is also repetitive since, during the lifetime of a dynamic coalition, member domains must undertake the task of negotiating common access states multiple times as domains leave and new ones join the coalition. To define and verify the correctness of tools for automated negotiation, we develop a formal state-transition model of the process of negotiating a common access state. We extend an existing Role Based Access Control (RBAC) language to illustrate a wide variety of negotiation constraints and present a resolution procedure for verifying the satisfaction of such constraints in the state-transition model

Paradoxes and coping mechanisms in the servitisation journey

Servitisation is conceptualised as product manufacturers' transition towards bundling products and services to offer customers enhanced value. Scholars have raised concerns regarding the potential challenges that firms face during servitisation, often termed servitisation paradoxes. Limited studies have explored the paradoxes experienced during the servitisation journey and the associated coping mechanisms. We utilise the open-ended essay methodology to unravel various paradoxes and coping mechanisms to address the gap. We collected data in two stages—from 69 participants in the first stage and 32 in the second stage. The study's findings reveal three broad paradoxes: the paradox of organising (autonomy and control, efficiency and flexibility, formal and informal information flow, and employee and customer needs), the paradox of learning (prior knowledge and new knowledge), and the paradox of performance (short-term and long-term performance). In addition, we identify four coping practices: change management, open communication, training programmes and digitalisation. The study augments the prior literature by developing a conceptual framework that elucidates the coexistence of numerous paradoxes and coping mechanisms. © 2022 The Author

Inelastically scattering particles and wealth distribution in an open economy

Using the analogy with inelastic granular gasses we introduce a model for wealth exchange in society. The dynamics is governed by a kinetic equation, which allows for self-similar solutions. The scaling function has a power-law tail, the exponent being given by a transcendental equation. In the limit of continuous trading, closed form of the wealth distribution is calculated analytically.Comment: 8 pages 5 figure

Spatial interactions in agent-based modeling

Agent Based Modeling (ABM) has become a widespread approach to model complex interactions. In this chapter after briefly summarizing some features of ABM the different approaches in modeling spatial interactions are discussed. It is stressed that agents can interact either indirectly through a shared environment and/or directly with each other. In such an approach, higher-order variables such as commodity prices, population dynamics or even institutions, are not exogenously specified but instead are seen as the results of interactions. It is highlighted in the chapter that the understanding of patterns emerging from such spatial interaction between agents is a key problem as much as their description through analytical or simulation means. The chapter reviews different approaches for modeling agents' behavior, taking into account either explicit spatial (lattice based) structures or networks. Some emphasis is placed on recent ABM as applied to the description of the dynamics of the geographical distribution of economic activities, - out of equilibrium. The Eurace@Unibi Model, an agent-based macroeconomic model with spatial structure, is used to illustrate the potential of such an approach for spatial policy analysis.Comment: 26 pages, 5 figures, 105 references; a chapter prepared for the book "Complexity and Geographical Economics - Topics and Tools", P. Commendatore, S.S. Kayam and I. Kubin, Eds. (Springer, in press, 2014

Building International Business Theory: A Grounded Theory Approach

The field of international business (IB) is in need of more theory development (Morck & Yeung, 2007). As such, the main focus of our manuscript was to provide guidance on how to build IB specific theory using grounded theory (GT). Moreover, we contribute to future theory development by identifying areas within IB where GT can be applied and the type of research issues that can be addressed using this methodology. Finally, we make a noteworthy contribution by discussing some of GT’s caveats and limitations, particularly those relevant to IB. This effort is intended to spur further interest in the development of IB theory