Unconventional method used in synthesis of polyphosphoesters

Polyphosphonates, polyphosphates, polyarylazophosphonates and polyarylazophosphates were synthesized by a new alternative to the classical phase transfer catalysis, respectively, the modified inverse phase transfer catalysis (IPTC) polycondensation of various phenylphosphonic (phosphoric) dichlorides (phenylphosphonic dichloride, phenylphosphoric dichloride, p-chlorophenylphosphoric dichloride) with bisphenols: bisphenol A, tetrabromobisphenol A, bis-(4-hydroxyphenyl)methane (bisphenol F), 4,4′-dihydroxyazobenzene. The polymers were characterized by infrared spectroscopy and magnetic resonance (¹H-NMR, ³¹P-NMR, ¹³C-NMR) spectroscopy. Yields in the range of 63.5–85% and molecular weights (M _w) of ~2,000–8,200 g mol^?1 were obtained. Polyphosphonates were stable up 210–270 °C and polyphosphates up 190–220 °C in air atmosphere. For a correct estimation of the thermal behavior of similar compounds, a kinetic analysis using a modified version of Non Parametric Kinetic method for representative polyphosphonate and polyphosphate was realized. The studies made on the hydrolytic degradation of the synthesized polyphosphates show that the most stable polymer under alkali-catalyzed degradation is the polyphosphate obtained by IPTC of phenylphosphoric dichloride and bisphenol A.     

In-situ fabrication of polyacrylate-silver nanocomposite through photoinduced tandem reactions involving eosin dye

A silver-acrylate nanocomposite was prepared using a novel one-pot strategy involving eosin dye as visible sensitizer and an amine derivative as radicals' source. The mechanism highlighted by steady state photolysis and time-resolved absorption spectroscopy lies on the initial formation of a strong ion-pair complex between eosin and Ag⁺. Upon visible irradiation, the excited triplet state of the metal complex efficiently abstracts a hydrogen atom from the amine and produces an α-aminoalkyl radical. In acrylate monomer matrix, such a strong reactive species initiates a free radical photopolymerization and also provides the reduction of the silver cation. Through this ‘in-situ’ fabrication method, the kinetics formation of the nanocomposite and its detailed structural analysis are characterized by UV-visible, real-time FTIR absorption spectroscopy and by transmission electron microscopy.     

Application of SMA Composites in the Collectors of the Railway Pantograph for the Italian High-Speed Train

In high-speed train operation the flexural modes of the collector play a significant role in the vibrations for the frequencies over 40-50 Hz. In a previous work it has been established that a possible way to increase the modal damping of these flexural modes, without deep modification of the collector structure, is to increase the specific damping of the lateral horns, usually made of glass fiber polymer. Ni-Ti alloy yarns can be used as “smart fibers” embedded in this conventional material in order to make new horns with increased damping capacity, with a configuration of laminated composite material. The first step of the work herein presented consists in setting, through a proper thermal treatment, martensitic structure within the pantograph working temperature range, in order to obtain damping capabilities at low amplitude strain in the range 10^?4-10^?3. Afterwards a series of dynamic tests aimed at identifying the damping capacity of the NiTi wires has been undertaken. A finite element (FE) model of the SMA composites horn has been finally validated, comparing the results of dynamic numerical analysis with the results of measurements.     

Event-Based Interaction Management for Composite E-Services in eFlow

The Web is rapidly becoming the platform through which many companies deliver e-services to businesses and individual customers. E-Services are typically delivered in their primitive forms, called basic services. However, today's business environment creates the opportunity for providing value-added, integrated services, delivered by composing existing e-services, possibly offered by different providers.In order to enable organizations to pursue this business opportunity we have developed eFlow, a model and architecture that support the specification, enactment, and management of composite e-services, modeled as processes that are enacted by a process engine. In this paper we focus on one of the most important and innovative aspects of eFlow: that of the integration between service composition and event management. In particular, we extend classic service composition model by allowing composite services to publish and receive events. This capability enables composite services to dynamically exchange data with other applications (in the form of event parameters), to synchronize service invocations with the occurrence of (external or internal) events, and to handle exceptions occurring during service execution. One of our main objectives has been that of defining a model that is easy to understand and easy to use. Indeed, all types of events are handled in the same fashion from the user perspective, and high-level constructs are provided to handle critical events such as those related to time management. Finally, we show how the proposed approach can be implemented by integrating existing technologies.     

Service Mosaic: A Model-Driven Framework for Web Services Life-Cycle Management

Although Web services provide abstractions for simplifying integration at lower levels of the interaction stacks, they don't yet help simplify integration at higher abstraction levels such as business-level interaction protocols. Using a model-driven framework for Web services life-cycle management, the authors help facilitate the scalable development and maintenance of service-oriented applications by analyzing and managing Web service business protocols. Instead of using simple black and white measures,they identify different classes of protocol compatibility and replaceability. They implemented this framework in a prototype platform called Service Mosaic.     

Managing Workflow Authorization Constraints through Active Database Technology

The execution of workflow processes requires authorizations for enforcing the assignment of tasks to agents, either human or automated, according to the security policy of the organization. This paper presents a workflow authorization framework based on roles and organizational levels, and on authorization constraints. To facilitate the assignment of tasks to agents, roles and organizational levels are organized into hierarchies. Authorization constraints are introduced to specify instance-dependent, time-dependent, and history-dependent authorizations. Authorization constraints are specified in terms of active rules, used also for authorization management. The Workflow Management System determines authorized agents on the basis of the contents of an authorization base maintained through the active rules defined in the system.     

Modeling and Managing Interactions among Business Processes

Most workflow management systems (WfMSs) only support the separate andindependent execution of business processes. However, processes often needto interact with each other, in order to synchronize the execution of theiractivities, to exchange process data, to request execution of services, orto notify progresses in process execution. Recent market trends also raisethe need for cooperation and interaction between processes executed in differentorganizations, posing additional challenges. In fact, in order to reduce costsand provide better services, companies are pushed to increase cooperation and toform virtual enterprises, where business processes span across organizationalboundaries and are composed of cooperating workflows executed in differentorganizations. Workflow interaction in a cross-organizational environment iscomplicated by the heterogeneity of workflow management platforms on top ofwhich workflows are defined and executed and by the different and possiblycompeting business policies and business goals that drive process executionin each organization.In this paper we propose a model and system that enable interactionbetween workflows executed in the same or in different organizations. Weextend traditional workflow models by allowing workflows to publish andsubscribe to events, and by enabling the definition of points in the processexecution where events should be sent or received. Event notifications aremanaged by a suitable event service that is capable of filtering andcorrelating events, and of dispatching them to the appropriate targetworkflow instances. The extended model can be easily mapped onto anyworkflow model, since event specific constructs can be specified by means ofordinary workflow activities, for which we provide the implementation. Inaddition, the event service is easily portable to different platforms, anddoes not require integration with the WfMS that supports the cooperatingworkflows. Therefore, the proposed approach is applicable in virtually anyenvironment and is independent on the specific platform adopted     

Use of chitosan complex with aminophosphonic groups and cobalt for the removal of Sr2+ ions

We briefly describe the adsorbent performance of the chitosan complex with aminophosphonic groups and cobalt in the removal process of Sr²⁺ ions from aqueous solutions. The strontium adsorption was studied as a function of pH, contact time, and initial strontium concentration. Adsorption isotherms such as Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin were used to analyze the equilibrium data at different concentrations. The kinetics of the Sr²⁺ sorption was analyzed using the pseudo-first-order and pseudo-second-order kinetic models. The results clearly indicate that the chitosan complex with aminophosphonic groups and cobalt is an efficient adsorbent with respect to its capacity to absorb Sr²⁺ ions from aqueous solutions.