Magneto-superconductivity of 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10

Studied 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10 (Ru-1222) compound crystallized in a tetragonal I4/mmm space group crystal structure. Thermo-gravemetric (TG) analysis of the compound showed the release of oxygen and breaking to metallic constituents in two distinct steps at around 350 and 500 0C. The DC magnetization data (M vs. T) revealed magnetic transition at 100 K followed by superconducting transition at 40 K. Low field M vs. H hysteresis loop showed a lower critical field (Hc1) value of around 25 Oe. Ferromagnetic component is evidenced at 5, 10, 20 and 40 K. Near saturation field of above 5 Tesla is observed at 5 K. Zero-field returning moment (Mr) and zero-moment coercive field (Hc) values at 5 K are 0.35mB and 250 Oe. The resistance vs. temperature (R vs. T) behaviour of the sample confirmed superconductivity at around 43 K. Superconductivity transition (Tc) is broadened under magnetic field with strong granularity like steps.Comment: 16 pages including text and six figure

Theoretical evaluation of ex-vessel monitoring for initial fuel loading of a liquid metal fast breeder reactor

Transport theory calculations were used to determine the feasibility of monitoring the fuel loading to initial criticality of the Clinch River Breeder Reactor (CRBR) with a detector in a cavity outside the reactor vessel. Such monitoring of the CRBR with an ex-vessel detector will be different from monitoring of previous LMFBRs, where in-vessel detectors were used. The feasibility of ex-vessel monitoring will depend mainly on two criteria: (1) sensitivity - will there be enough counts to obtain adequate counting statistics; and (2) interpretability - will the count rate obtained during the initial fuel loading sequence be sufficient to determine the neutron multiplication or reactivity. Satisfying these criteria will assure that the reactor can be loaded safely to initial criticality. The sensitivity criterion can be satisfied by inserting an additional neutron source (one much more intense than the inherent neutron source of the fuel subassemblies) into the core center and using ex-vessel detectors with high sensitivity, such as multiple BF/sub 3/ counters mounted in a graphite moderator block. These calculations were used to determine the intensity of the additional source required to produce adequate counting rates at the ex-vessel detectors

Development and evaluation of an in-vehicle information system

In this paper, the authors introduce an In-Vehicle Information System (IVIS) which will manage messages from a variety of Advanced Traveler Information Services (ATIS) devices which can be installed in a road vehicle. The IVIS serves as the interface between the driver and the driving information environment. Increasingly, aftermarket systems, such as routing and navigation aids, are becoming available which can be added to vehicles to aid in travel and/or the conduct of business in the vehicle. The installation of multiple devices, each with its own driver interface, increases the likelihood of driver distraction and thus the risk of an accident. The goal of this project is the development of a fully-integrated IVIS which will filter, prioritize and display highway and vehicle information safely and efficiently, while also providing an integrated driver interface to a variety of ATIS information sources. Because these devices will be integrated into IVIS as components, they are referred to in this paper as IVIS subsystems. Such a system, using modern digital technology, will tailor information both to the driver`s needs and to the driving environment. A variety of other efforts, both in the Us and abroad, either have been completed or are nearing completion, and the results of these efforts will be incorporated into this present system. IVIS must perform three high level functions (Tufano, et al, 1997). It must (1) interact with (ATIS) subsystems, (2) management information, and (3) interact with the driver. To safely develop and evaluate such a device, a platform must be devised which permits testing in an off-road setting

In-vehicle information system functions

This paper describes the functional requirement for an In-Vehicle Information System (IVIS), which will manage and display all driving-related information from many sources. There are numerous information systems currently being fielded or developed (e.g., routing and navigation, collision avoidance). However, without a logical integration of all of the possible on-board information, there is a potential for overwhelming the driver. The system described in this paper will filter and prioritize information across all sources, and present it to the driver in a timely manner, within a unified interface. To do this, IVIS will perform three general functions: (1) interact with other, on-board information subsystems and the vehicle; (2) manage the information by filtering, prioritizing, and integrating it; and (3) interact with the driver, both in terms of displaying information to the driver and allowing the driver to input requests, goals and preferences. The functional requirements described in this paper have either been derived from these three high-level functions or are directly mandated by the overriding requirements for modularity and flexibility. IVIS will have to be able to accommodate different types of information subsystems, of varying level of sophistication. The system will also have to meet the diverse needs of different types of drivers (private, commercial, transit), who may have very different levels of expertise in using information systems

Opening up the Quantum Three-Box Problem with Undetectable Measurements

One of the most striking features of quantum mechanics is the profound effect exerted by measurements alone. Sophisticated quantum control is now available in several experimental systems, exposing discrepancies between quantum and classical mechanics whenever measurement induces disturbance of the interrogated system. In practice, such discrepancies may frequently be explained as the back-action required by quantum mechanics adding quantum noise to a classical signal. Here we implement the 'three-box' quantum game of Aharonov and Vaidman in which quantum measurements add no detectable noise to a classical signal, by utilising state-of-the-art control and measurement of the nitrogen vacancy centre in diamond. Quantum and classical mechanics then make contradictory predictions for the same experimental procedure, however classical observers cannot invoke measurement-induced disturbance to explain this discrepancy. We quantify the residual disturbance of our measurements and obtain data that rule out any classical model by > 7.8 standard deviations, allowing us for the first time to exclude the property of macroscopic state-definiteness from our system. Our experiment is then equivalent to a Kochen-Spekker test of quantum non-contextuality that successfully addresses the measurement detectability loophole

Assessment of the roles of the Advanced Neutron Source Operators

The Advanced Neutron Source (ANS) is unique in the extent to which human factors engineering (HFE) principles are being applied at the conceptual design stage. initial HFE accomplishments include the development of an ANS HFE program plan, operating philosophy, and functional analysis. In FY 1994, HFE activities focused on the role of the ANS control room reactor operator (RO). An operator-centered control room model was used in conjunction with information gathered from existing ANS system design descriptions and other literature to define a list of RO responsibilities. From this list, a survey instrument was developed and administered to ANS design engineers, operations management personnel at Oak Ridge National Laboratory`s High Flux Isotope Reactor (HFIR), and HFIR ROs to detail the nature of the RO position. Initial results indicated that the RO will function as a high-level system supervisor with considerable monitoring, verification, and communication responsibilities. The relatively high level of control automation has resulted in a reshaping of the RO`s traditional safety and investment protection roles

Operator Role Definition: An Initial Step in the Human Factors Engineering Design of the Advanced Neutron Source (ANS)

The Advanced Neutron Source (ANS) is a new basic and applied research facility sponsored by the U.S. Department of Energy that is proposed for construction. It will provide neutron beams for measurements and experiments in the fields of materials science and engineering, biology, chemistry, materials analysis, and nuclear science. The facility will provide a useful neutron beam flux that is at least five times more than is available at the world`s best existing facilities. It will also provide world-class facilities for isotopes production, materials irradiation testing, materials analysis, and the production of positrons. ANS will be unique in the United States in the extent to which human factors engineering (HFE) principles will be included in its design and construction. Initial HFE accomplishments include the development of a functional analysis, an operating philosophy, and a program plan. In fiscal year 1994, HFE activities are focusing on the role of the ANS control room reactor operator (RO). An operator-centered control room model was used in conjunction with information gathered from existing ANS system design descriptions and other literature to define RO responsibilities. From this list, a survey instrument was developed and administered to ANS design engineers, operations management personnel at Oak Ridge National Laboratory`s High Flux Isotope Reactor (HFIR), and HFIR ROs to detail the nature of the RO position. Initial results indicated that the RO should function as a high-level system supervisor with considerable monitoring, verification, and communication responsibilities. The relatively high level of control automation has resulted in a reshaping of the RO`s traditional safety and investment protection roles