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Titanium alloys have high specific strength and corrosion resistance, which have promising applications in industry. However, the machinability of titanium alloys is limited due to their crystal lattice and physical properties. Thus, in recent years, the superplastic forming of titanium alloys has been intensively developing, in particular, forming at low temperatures and/or high strain rates. In this work, a tensile test of low-cost Ti-2Fe-0.1B alloys was carried out at a temperature of 550~750 °C and a strain rate of 1 × 10−3 s−1~1 × 10−2 s−1. The results showed that the alloy exhibited good superplasticity even at a high strain rate (1 × 10−2 s−1) and a low deformation temperature of 550 °C; the elongation of the alloy in this state reached 137.5%. The high strain rate sensitivity coefficient m (0.3) and the maximum elongation (452%) were obtained at a strain rate of 1 × 10−3 s−1 and a temperature of 750 °C. Characteristics of the microstructure showed that during superplastic deformation, the recrystallization and grain boundary sliding of the alloy phases were accelerated, which could be ascribed to the effect of the element Fe. At the same time, the TiB phase located around the primary elongated α grains could also induce dynamic recrystallization and dynamic globularization during deformation. [ABSTRACT FROM AUTHOR]

In recent decades, the effect of Fe element addition on titanium alloy has been investigated extensively due to the development of low-cost titanium alloys, as well as B microalloying, which could decrease the grain size of titanium alloys during the casting process. As a key structural material, the study of the fatigue behavior of titanium alloys is crucial and always attractive for scientists. Hence, in this paper, the low cycle fatigue (LCF) behavior and fracture characteristics of a low-cost Ti-2Fe-0.1B alloy with a lamellar structure were investigated systematically, five different strain amplitudes (Δεt/2) in the range from 0.6% to 1.4% were selected to control the LCF process. It was found that the Ti-2Fe-0.1B alloy exhibits continuous cyclic softening behavior in the cycle as a whole at Δεt/2 ≤ 1.2%, while at Δεt/2 = 1.4%, it exhibits slight cyclic hardening at the initial stage of the cycle, then shows cyclic softening. Compared with pure titanium and other typical titanium alloys, the Ti-2Fe-0.1B alloy indicated maximum fatigue life under the same strain amplitude, it can be attributed to the fine grain size result from the effect of Fe element and trace B, which could hinder the dislocation movement and crack propagation. [ABSTRACT FROM AUTHOR]

In the present study, a novel Ti-2Fe-0.1B alloy was processed using equal channel angular pressing (ECAP) via route Bc for four passes. The isochronal annealing of the ultrafine-grained (UFG) Ti-2Fe-0.1B alloy was conducted at various temperatures between 150 and 750 °C with holding times of 60 min. The isothermal annealing was performed at 350–750 °C with different holding times (15 min–150 min). The results indicated that no obvious changes in the microhardness of the UFG Ti-2Fe-0.1B alloy are observed when the annealing temperature (AT) is up to 450 °C. Compared to the UFG state, it was found that excellent strength (~768 MPa) and ductility (~16%) matching can be achieved for the UFG Ti-2Fe-0.1B alloy when annealed at 450 °C. The microstructure of the UFG Ti-2Fe-0.1B alloy before and after the various annealing treatments was characterized using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). It was found that the average grain size remained at an ultrafine level (0.91–1.03 μm) when the annealing temperature was below 450 °C. The good thermal stability of the UFG Ti-2Fe-0.1B alloy could be ascribed to the pinning of the TiB needles and the segregation of the Fe solute atoms at the grain boundaries, which is of benefit for decreasing grain boundary energy and inhibiting the mobility of grain boundaries. For the UFG Ti-2Fe-0.1B alloy, a recrystallization activation energy with an average value of ~259.44 KJ/mol was analyzed using a differential scanning calorimeter (DSC). This is much higher than the lattice self-diffusion activation energy of pure titanium. [ABSTRACT FROM AUTHOR]

The ATLAS collaboration at CERN operated a combined test beam (CTB) from May until November 2004. The prototype of ATLAS data acquisition system (DAQ) was used to integrate other subsystems into a common CTB setup. Data were collected synchronously from all the ATLAS detectors, which represented nine different detector technologies. Electronics and software of the first level trigger were used to trigger the setup. Event selection algorithms of the high level trigger were integrated with the system and were tested with real detector data. The possibility to operate a remote Event Filter farm synchronized with the ATLAS Trigger and Data Acquisition System (TDAQ) was also tested. Event data, as well as detector conditions data, were made available for offline analysis.

In the ATLAS experiment at the LHC, the output of read-out hardware specific to each subdetector will be transmitted to buffers, located on custom made PCI cards ('ROBINs'). The data consist of fragments of events accepted by the first-level trigger at a maximum rate of 100 kHz. Groups of four ROBINs will be hosted in about 150 Read-Out Subsystem (ROS) PCs. Event data are forwarded on request via Gigabit Ethernet links and switches to the second-level trigger or to the Event builder. In this paper a discussion of the functionality and real-time properties of the ROS is combined with a presentation of measurement and modelling results for a testbed with a size of about 20% of the final DAQ system. Experimental results on strategies for optimizing the system performance, such as utilization of different network architectures and network transfer protocols, are presented for the testbed, together with extrapolations to the full system. Index Terms--ATLAS, data acquisition, LHC, real-time systems, triggering.

The Online Software is the global system software of the ATLAS data acquisition (DAQ) system, responsible for the configuration, control and information sharing of the ATLAS DAQ System. A test beam facility offers the ATLAS detectors the possibility to study important performance aspects as well as to proceed on the way to the final ATLAS DAQ system. Last year, three subdetectors of ATLAS--separately and combined--were successfully using the Online Software for the control of their datataking. In this paper, we describe the different components of the Online Software together with their usage at the ATLAS test beam. Index Terms--Control systems, data acquisition, elementary particle, physics, software.

The Process Management component of the online software of the future ATLAS experiment data acquisition system is presented. The purpose of the Process Manager is to perform basic job control of the software components of the data acquisition system. It is capable of starting, stopping and monitoring the status of those components on the data acquisition processors independent of the underlying operating system. Its architecture is designed on the basis of a server client model using CORBA based communication. The server part relies on C++ software agent objects acting as an interface between the local operating system and client applications. Some of the major design challenges of the software agents were to achieve the maximum degree of autonomy possible, to create processes aware of dynamic conditions in their environment and with the ability to determine corresponding actions. Issues such as the performance of the agents in terms of time needed for process creation and destruction, the scalability of the system taking into consideration the final ATLAS configuration and minimizing the use of hardware resources were also of critical importance. Besides the details given on the architecture and the implementation, we also present scalability and performance tests results of the Process Manager system. Index Terms--Data acquisition, job control, process management, process monitoring, software agents.

Presents a study which performed quantitative x-ray diffraction measurements on a nanocrystalline copper sample made by severe plastic deformation. Experimental results; Discussion and conclusions.

The DAQ group of the future ATLAS experiment has developed a prototype system based on the Trigger/DAQ architecture described in the ATLAS Technical Proposal [1] to support studies of the full system functionality, architecture as well as available hardware and software technologies. One sub-system of this prototype is the back-end which encompasses the software needed to configure, control and monitor the DAQ, but excludes the processing and transportation of physics data. The back-end consists of a number of components including run control, configuration databases and message reporting system. The software has been developed using standard, external software technologies such as OO databases and CORBA. It has been ported to several C++ compilers and operating systems including Solaris, Linux, WNT and LynxOS. This paper gives an overview of the back-end software, its performance, scalability and current status.

We present a new giant magnetoresistance (GMR) material composed of polyaniline, polystyrene, sulfur, manganese acetylacetonate, lanthanum, and praseodymium chlorides. These compounds were mixed and processed mechanochemically to obtain thin films. External magnetic field of 6000 Oe increases conductivity of films by more than 300%. Analysis of transient current kinetics after application of constant voltage (10 V) to samples showed the existence of three types of charge carriers, which we identified as e-, H+, and Cl-. Contribution of functional groups of polyaniline and elemental sulfur S in the formation of the above charge carriers in this new GMR composite material is discussed. [ABSTRACT FROM AUTHOR]

Coordination polymers exhibiting magnetic properties can be considered as promising materials for magnetic applications. We obtained such materials by means pf mechanochemical incorporation of binuclear metal complexes Mn–O–Mn into polystyrene. Incorporation of binuclear manganese complexes was achieved by using substituted benzoquinones (organic acceptors) as intermediate ligands that react with manganese acetylacetonate and provide new coordination and stabilization of manganese in different valence states. Magnetic transitions in this system are due to reversible disproportionation process Mn3+–O–Mn3+⇔Mn2+–O–Mn4+ in the binuclear complex. The structure of the binuclear complex was obtained using ab initio calculations. [ABSTRACT FROM AUTHOR]

We report on mechanochemical synthesis and magnetic and electric properties of organic polymeric semiconductor that contains paramagnetic and ferromagnetic particles. As starting materials we used polyaniline (emeraldine base), polystyrene, FeCl3, and elemental sulfur. These components were chosen for the purpose of obtaining semiconductor polymer composite containing magnetic iron nanoparticles and having flexible thermomechanical properties. The presence of nanoparticles was evidenced by scanning electron microscopy. The value of conductivity of the Fe-doped polymer composite was increased by several orders of magnitude compared to the initial undoped polyaniline. Temperature dependence of the conductivity shows semiconductor character of the composite material. [ABSTRACT FROM AUTHOR]