Production of a superconducting Bi-Pb-Sr-Ca-Cu oxide wire using a hot-extrusion process

A Bi_1.84Pb_0.34Sr₂Ca₂Cu₃O_y sample, sheathed with Ag, was hot-extruded into a wire with a high reduction ratio of 91 % in area. The c axis of the extruded oxide was normal to the extrusion direction. Subsequent swaging and rolling at room temperature and annealing for 200 h at 1113 K in air resulted in a high-T_c superconducting composite tape exhibiting a J_c value of 5900 A/cm² at 77 K in zero applied field. The hot-extrusion process is useful as the first deformation process to produce the superconducting oxide tape with a favorable orientation structure.     

MORT WorkSheet or how to make MORT analysis easy

The article is devoted to incident investigation, specifically to one of its aspects: the satisfactory identification of root causes. Management Oversight and Risk Tree (MORT) technique is exploited as a tool that helps to fulfill the task. However, since the application of traditional MORT diagrams was not considered satisfactory, a new software tool MORT WorkSheet was developed to make the MORT analysis easier. The article explains what led to the development of the software tool, how the tool works, and what results it is able to provide. An incident example is used in the article that illustrates how the new tool is applied during the investigation and how the results of its application look. Final comparison shows how different the obtained results may be with support of the MORT WorkSheet from the results of conventional incident investigation.     

Using quantum interferometers to make measurements at the Heisenberg limit

In recent work we proposed a quantum interferometer and showed how it could be used to significantly enhance the resolution that could be achieved in measurement schemes. In this paper, we outline a detailed scheme on how these quantum interferometers could be implemented. We also analyze the effects of dissipation and of imperfect detectors and show that this scheme is remarkably robust to both. This suggests that quantum interferometers may provide a promising route for implementing sub-shot-noise limited measurements in the laboratory.     

Using big data to make better decisions in the digital economy

The question this special issue would like to address is how to harvest big data to help decision-makers to deliver better fact-based decisions aimed at improving performance or to create better strategy? This special issue focuses on the big data applications in supporting operations decisions, including advanced research on decision models and tools for the digital economy. Responds to this special issue was great and we have included many high-quality papers. We are pleased to present 13 of the best papers. The techniques presented include data mining, simulation and expert system with applications span across online reviews, food retail chain to e-health.     

Using saponified olive oil to make cost effective calcium carbonate particles superhydrophobic

The main goal of this paper is to show that superhydrophobic particles of calcium carbonate can be synthesized at low cost from harmless biocompatible natural products like baking soda (NaHCO₃) and olive oil. Calcium carbonate particles were prepared by precipitating solutions containing CO₃^2? and Ca²⁺ ions at two different temperatures 30 °C and 80 °C. These particles were transformed into hydrophobic ones using soap made from olive oil from the region of Kabylie (Algeria). The olive oil was first saponified. Adjusted amounts of this soap were added to the sodium carbonate solution before the precipitation reaction. Several techniques were used to analyze the products of the reaction. Typical polymorphs of CaCO₃ (calcite, aragonite and vaterite) were identified by quantitative analysis of X-ray powder diffraction patterns, giving their crystallite size and atomic fractions. Scanning electron microscopy was used to probe the morphology of the CaCO₃ particles. FT-IR measurements indicated the presence of aliphatic chains in the hydrophobic particles, thereby proving that the calcium carbonate particles were functionalized by soap. The particles which formed were found to be superhydrophobic with a contact angle of up to 175°. Evidence of the efficiency of these particles in oil spill recovery is given.     

Properties of nanostructured oxide formed during oxidation of a zirconium wire by supercritical water

Synthesis of ZrO₂ during oxidation of a zirconium wire by supercritical water at P = 25 MPa and T = 500 or 525°C has been investigated. It is established that an inhomogeneous nanostructured ZrO₂ layer is formed as a result of oxidation. Rate of 〈Zr〉 oxidation, oxide porosity and morphology, and average size and structure of crystallites are determined. The thermal conductivity of the synthesized ZrO₂ layer in supercritical water and in nitrogen is determined by pulsed electric heating of a partially oxidized wire. The low values of thermal conductivity (about 0.2 W/(m K)) correspond to a layered structure of porous material, with layers orientated parallel to the oxidized-metal surface.     

Using magnetic field pulses with a slow sweep rate to produce uniform current distribution in multifilamentary superconducting wire

A detailed discussion is presented on the change in current distribution which takes place in a twisted multifilamentary superconducting wire induced by successive magnetic field pulses with a slow sweep-rate. The number of the field pulses required for a localized current-distribution to become uniform is estimated. Some modification of existing theories is necessary to describe the phenomenon. The results obtained are confirmed by systematic measurements of the net flux penetration into the wire during each cycle of field pulses.     

Development of an analytical method to break logical loops at the system level

Logical loops or circular logics are interpreted as circular supporting relations among systems or their fault trees. The logical loops are located in the merged fault tree that is created by combining the system fault trees. The inconsistent manual breaking of the logical loops could be one of the major sources of the uncertainty in the fault tree analysis. This paper presents an analytical method to break the logical loops at the system level. The analytical solution at the system level is obtained in a mathematical way without an actual manipulation of the fault tree. Then, the actual manipulation of the fault tree in the analytical solution is performed and the resultant broken fault tree is solved by the fault tree quantifier.The analytical solution is consistent regardless of the knowledge, experiences, skills, and practices of the reliability specialist. The analytical solution of this method is easy to understand or trace how to break the logical loops. Reliability analysts and concerned people can communicate how to break the logical loops with the help of the mathematical expression of the analytical solution.     

Reflection and transmission properties of a wire grid embedded in a SNG or SZ medium

The reflection and transmission properties of a wire grid embedded in lossless Single Negative (SNG) or Single Zero (SZ) medium have been analytically studied. The wires of the grid are taken to be lossless as well as lossy. It is shown that a lossy grid has approximately identical reflection characteristics for the Transverse Magnetic incident wave with Epsilon Negative and Mu Negative background medium. The lossy grid with Epsilon Zero background medium acts as a perfect reflector for the normally incident wave. Likewise, it is further studied that a lossy wire grid embedded in Mu Zero medium can be cloaked for the incoming normally incident wave.     

How to make an autonomous robot as a partner with humans: design approach versus emergent approach

In this paper, we discuss what factors are important to realize an autonomous robot as a partner with humans. We believe that it is important to interact with people without boring them, using verbal and non-verbal communication channels. We have already developed autonomous robots such as AIBO and QRIO, whose behaviours are manually programmed and designed. We realized, however, that this design approach has limitations; therefore we propose a new approach, intelligence dynamics, where interacting in a real-world environment using embodiment is considered very important. There are pioneering works related to this approach from brain science, cognitive science, robotics and artificial intelligence. We assert that it is important to study the emergence of entire sets of autonomous behaviours and present our approach towards this goal.     

Using nano-QSAR to predict the cytotoxicity of metal oxide nanoparticles

It is expected that the number and variety of engineered nanoparticles will increase rapidly over the next few years, and there is a need for new methods to quickly test the potential toxicity of these materials. Because experimental evaluation of the safety of chemicals is expensive and time-consuming, computational methods have been found to be efficient alternatives for predicting the potential toxicity and environmental impact of new nanomaterials before mass production. Here, we show that the quantitative structure-activity relationship (QSAR) method commonly used to predict the physicochemical properties of chemical compounds can be applied to predict the toxicity of various metal oxides. Based on experimental testing, we have developed a model to describe the cytotoxicity of 17 different types of metal oxide nanoparticles to bacteria Escherichia coli. The model reliably predicts the toxicity of all considered compounds, and the methodology is expected to provide guidance for the future design of safe nanomaterials.     

The Decision to Stay or Resign Following an Acquisition by a Chinese or Indian Company

This paper analyses the challenges created by the liability of foreignness and the associated country-of-origin bias and their effect on Western managers’ decisions about whether to leave following their company’s acquisition by an emerging-economy multinational. Using a manipulated scenario-based survey conducted with American, French and German managers, the results show that managers are more likely to resign if their company is acquired by a company from an emerging economy (specifically, China or India) than by a company from their home or another Western, developed country. Furthermore, the results do not support previous research findings that show the role of prior alliance between the acquirer and its target, previous experience with successful acquisitions, previous experience with the local market and minimal post-acquisition integration to be forces helping to counterbalance the adverse effects of the liability of foreignness, country-of-origin bias and the ‘emergingness’ nature of foreign acquirers.     

Torsional impact of a layer or a cylinder bonded to an elastic half-space

In this paper two torsional impact problems are considered. The first problem deals with the solution of a layer bonded to an elastic half-space when the layer is driven by the torsional impact over a bonded rigid circular disc. In the second problem sudden torsion by a rigid disc attached over the plane face of a circular cylinder is considered and the rest of the plane surface of the cylinder is stress free. The cylinder is bonded to the half-space, making use of Laplace and Hankel transforms the solution of each problem is reduced into Fredholm integral equations of the second kind. A numerical Laplace inversion technique is then used to recover the time depencence of the solution. The numerical values for the applied torque at the surface of rigid disc are calculated for each problem and then are displayed graphically.     

Remagnetization of a circularly anisotropic amorphous wire in an alternating magnetic field

Remagnetization of an amorphous ferromagnetic wire with circular anisotropy in an alternating longitudinal magnetic field was theoretically studied within the framework of a quasistationary approximation. A frequency spectrum of the emf generated in a probing coil wound on the wire was determined, and analytical expressions describing the dependence of the emf amplitude on the alternating magnetic field amplitude H ₀ and the constant magnetic bias field value H _e were derived. The results can be applied to the development of weak magnetic field sensors.