The Elastic and Inelastic Scattering (EIS) beamline at the free-electron laser FERMI is presented. It consists of two separate end-stations: EIS-TIMEX, dedicated to ultrafast time-resolved studies of matter under extreme and metastable conditions, and EIS-TIMER, dedicated to time-resolved spectroscopy of mesoscopic dynamics in condensed matter. The scientific objectives are discussed and the instrument layout illustrated, together with the results from first exemplifying experiments.

In the past few years, we have been witnessing an increased interest for studying materials properties under non-equilibrium conditions. Several well established spectroscopies for experiments in the energy domain have been successfully adapted to the time domain with sub-picosecond time resolution. Here we show the realization of high resolution resonant inelastic X-ray scattering (RIXS) with a stable ultrashort X-ray source such as an externally seeded free electron laser (FEL). We have designed and constructed a RIXS experimental endstation that allowed us to successfully measure the d-d excitations in KCoF3 single crystals at the cobalt M2,3-edge at FERMI FEL (Elettra-Sincrotrone Trieste, Italy). The FEL-RIXS spectra show an excellent agreement with the ones obtained from the same samples at the MERIXS endstation of the MERLIN beamline at the Advanced Light Source storage ring (Berkeley, USA). We established experimental protocols for performing time resolved RIXS experiments at a FEL source to avoid X ray-induced sample damage, while retaining comparable acquisition time to the synchrotron based measurements. Finally, we measured and modelled the influence of the FEL mixed electromagnetic modes, also present in externally seeded FELs, and the beam transport with ~120 meV experimental resolution achieved in the presented RIXS setup.

Group communication is one of the main paradigms for implementing replication middleware. The high run-time costs of group communication may constitute a major performance bottleneck for modern enterprise applications. In this paper we investigate the applicability of message packing, a technique originally proposed by Friedman and Van Renesse in 1997 for improving the performance of group communication, to modern hardware and group communication toolkits. Most importantly, we extend this technique with a policy for varying the packing degree automatically, based on dynamic estimates of the optimal packing degree. The resulting system is adaptive in that it allows exploiting message packing efficiently in a dynamic and potentially unknown run-time environment. Several case studies are analyzed.

SUMMARYWe propose a service replication framework for unreliable networks. The service exhibits the same consistency guarantees about the order of execution of operation requests as its non-replicated implementation. Such guarantees are preserved in spite of server replica failure or network failure (either between server replicas or between a client and a server replica), and irrespective of when the failure occurs. Moreover, the service guarantees that in the case when a client sends an 'update' request multiple times, there is no risk that the request be executed multiple times. No hypotheses about the timing retransmission policy of clients are made, e.g. the very same request might even arrive at different server replicas simultaneously. All of these features make the proposed framework particularly suitable for interaction between remote programs, a scenario that is gaining increasing importance. We discuss a prototype implementation of our replication framework based on Tomcat, a very popular Java-based Web server. The prototype comes into two flavors: replication of HTTP client session data and replication of a counter accessed as a Web service.

Cyberinfrastructures that are being built in the United States and in Europe have the goal of enabling large-scale distributed science and engineering collaborations. However, there is still the need for effective groupware tools that will enable distributed and heterogeneous teams of people to effectively collaborate within these global scenarios. This chapter presents a Web-based groupware tool that is being developed in the context of the GRIDCC European project, whose purpose is to extend current cyberinfrastructures to enable shared access to and control of distributed instrumentation. We discuss the challenges in developing groupware solutions for different social and organizational contexts, and present the main features of a prototype we have designed