A distributed command governor based on graph colorability theory

In this paper, a distributed command governor (CG) strategy is introduced that, by the use of graph colorability theory, improves the scalability property and the performance of recently introduced distributed noncooperative sequential CG strategies. The latter are characterized by the fact that only 1 agent at a decision time is allowed to update its command, whereas all the others keep applying their previously computed commands. The scalability of these early CG distributed schemes and their performance are limited because the structure of the constraints is not taken into account in their implementation. Here, by exploiting the idea that agents that are not directly coupled by the constraints can simultaneously update their control actions, the agents in the network are grouped into particular subsets (turns). At each time instant, on the basis of a round‐robin policy, all agents belonging to a turn are allowed to update simultaneously their commands, whereas agents in other turns keep applying their previous commands. Then, a turn‐based distributed CG strategy is proposed and its main properties are analyzed. Graph colorability theory is used to determine the minimal number of turns and to distribute each agent in at least a turn. A novel graph colorability problem that allows one to maximize the frequency at which agents can update their commands is proposed and discussed. A final example is presented to illustrate the effectiveness of the proposed strategy.     

Some recent advances in polyolefin functionalization

Polyolefin‐based materials are increasingly being used in many industrial applications for packaging, automotive and construction materials. The recent developments of research have been aimed at making these materials, often complex, being mixtures, block copolymers, micro‐ and nanocomposites with inorganic and organic fillers, more efficient and environmentally friendly (through recycling processes, and the use of bio‐polyolefins). In this context, functionalized polyolefins, on the one hand, play a fundamental role in improving the morphology and thus the thermal and mechanical properties of heterophase systems, and, on the other hand, provide new materials difficult to obtain by conventional synthesis in connection with the type of inserted functionality. Therefore it appears to be of interest to report and discuss here the recent results concerning the radical grafting in the melt of different functionalities onto polyolefins as well as the capability reached of modulating ad hoc the degree of grafting and the final structure/architecture of functionalized polyolefins. © 2013 Society of Chemical Industry     

The influence of process-oriented organisational design on operational performance and innovation: a quantitative analysis in the financial services industry

Market competition requires that organisations excel at both operational performance and innovation. Though process orientation is intended to benefit operations in general, the impact of specific elements remains unclear. The purpose of this study is to identify the specific organisational design components of process orientation that simultaneously influence operational performance and innovation. We survey employees in the financial services sector (N = 1069) regarding the influence of six process-oriented organisation design components on operational performance and innovation using PLS-SEM. The results indicate that organisational structure and process improvement encourage both operational performance and innovation. Personal autonomy is partially beneficial, while the others have no joint influence on operational performance and innovation. This study is first in providing evidence regarding the influence of a broad variety of organisational design components of process orientation on operational performance and innovation. The study contributes to theory on how process orientation improves operational performance and innovation. The findings can serve as a guideline for managers and organisations as to which organisational design components should be implemented to improve operations.     

Investigation of Origin of Attached Cu-Ag Droplets to Solid Particles During High-Temperature Slag/Copper/Spinel Interactions

Metallurgical and Materials Transactions B - This study investigates the origin of mechanically entrained metal droplets in liquid slag due to their interaction with solid spinel particles. Two...     

Provably-Secure Time-Bound Hierarchical Key Assignment Schemes

A time-bound hierarchical key assignment scheme is a method to assign time-dependent encryption keys to a set of classes in a partially ordered hierarchy, in such a way that each class can compute the keys of all classes lower down in the hierarchy, according to temporal constraints.     

Microstructure of Low C Steel Isothermally Transformed in the M S to M f Temperature Range

An isothermal transformation was observed when a fully austenitized lean-alloyed, low C steel was quenched to a temperature in the M _S to M _f temperature range and held at the quenching temperature. The dilatometric analysis revealed that the isothermal transformation was distinct from the bainitic transformation. Internal friction (IF) measurements and X-ray diffraction (XRD) analysis showed that the dislocation density in the isothermal transformation product was larger than in lower bainite, and lower than in athermal martensite. Microstructural analysis by transmission electron microscopy (TEM) revealed that the isothermal transformation product had a specific microstructure consisting of large lath-type constituent units with wavy boundaries, with a Nishiyama?CWassermann orientation relationship (NW OR) with respect to the parent austenite. The isothermal transformation below M _S proceeds by the thickening of athermally formed laths.     

Predicting mode-II delamination suppression in z-pinned laminates

A finite element model for predicting delamination resistance of z-pin reinforced laminates under the mode-II load condition is presented. End notched flexure specimen is simulated using a cohesive zone model. The main difference of this approach to previously published cohesive zone models is that the individual bridging force exerted by z-pin is governed by a specific traction-separation law derived from a unit-cell model of single pin failure process, which is independent of the fracture toughness of the unreinforced laminate. Therefore, two separate traction-separation laws are employed; one represents unreinforced laminate properties and the other for the enhanced delamination toughness owing to the pin bridging action. This approach can account for the so-called large scale bridging effect and avoid using concentrated pin forces in numerical models, thus removing the mesh-size dependency and permitting more accurate and reliable computational solutions.     

Adsorption of pharmaceuticals from aqueous solutions on synthetic zeolites

The objectives of this study were to measure the sorption capacity of a dilute solution of drugs in water on hydrophobic zeolites and to quantify aspects of their adsorption mechanisms for potential use in wastewater remediation. The removal of three drugs, erythromycin (ERY), carbamazepine (CBZ) and levofloxacin (FLX) from water using three organophilic zeolites (Y, mordenite (MOR), ZSM-5) was investigated. Adsorption isotherms show that these three drugs are adsorbed in remarkable amounts by Y. These data were confirmed by thermogravimetric analysis. The presence of these drugs inside the Y cage was revealed by unit cell parameter variations and structural deformations obtained by X-ray structure analyses carried out using the Rietveld method on zeolite after adsorption. Our results indicate that the adsorption properties of zeolitic materials do not only depend on micropore size and that zeolite shape selectivity also depends on structural features which are difficult to determine “a priori”. In order to test the ability of organophilic zeolites in removing drugs from wastewater, the adsorption of ERY, FLX and CBZ on zeolite Y from water samples collected at the outlet of a wastewater treatment plant located in Northern Italy was determined. These drugs were almost completely adsorbed by Y zeolite, confirming that this material is suitable for removing drugs from wastewater.