Fiber-optic interferometric strain gauge producing asymmetricfringes by using nonlinear feedback

Source wavelength modulation by feedback of the interference signal of an unbalanced fiber-optic Michelson interferometer to the driver of the semiconductor laser source gives rise to sawtooth shaped fringes under fiber strain. The dependence of the theoretically predicted fringe asymmetry on feedback gain is verified experimentally. Elimination of the fringe counting directional ambiguity via differentiation of the asymmetric closed loop interference signal is demonstrated for the first time     

Multistable fiber-optic Michelson interferometer with electroopticfeedback exhibiting 95 stable states

The multistable behavior of a fiber-optic Michelson interferometer with electrooptic feedback using a piezoelectric phase modulator is investigated. A linear stability analysis of the third-order differential equation used to describe the system reveals the number of stable states increases with the ratio τ/T of the system time constant (τ) and the feedback delay time (T). In laboratory investigations 95 stable states were achieved with τ/T>50     

Unambiguous sawtooth fringe counting for an active homodynedemodulated interferometric strain gauge

Source wavelength modulation by feedback of the interference signal of an unbalanced fiber-optic Michelson interferometer to the driver of the semiconductor laser source gives rise to sawtooth-shaped fringe's under fiber strain. The fringe asymmetry is utilized for elimination of the fringe counting directional ambiguity via differentiation of the closed-loop interference signal. Initial results of quantitative strain measurements agree reasonably well with the readout of a resistive strain gauge as well as with the theoretically predicted sensitivity     

Scopus scientific mapping production in industry 4.0 (2011–2018): a bibliometric analysis

Research in industry 4.0 is growing, driven by the innovations in production systems on a continuous basis. In this study, we identified the evolution of themes inherent in the industry 4.0 using a bibliometric software, namely SciMAT (Science Mapping Analysis Software Tool). The analyses included 1882 documents, 4231 keywords, and the relevant information was extracted based on frequency of co-occurrence of keywords. The clusters were plotted in two-dimensional strategic diagrams and analysed using the bibliometric indicators such as the number of publications, number of associated documents, and h-index. The results revealed that 2017 had the largest number of publications. Expert authors in the field and the periodicals that published the most were identified. The science mapping presented 31 clusters in which the most representative motor themes were CPS (Cyber-Physical System), IoT (Internet of Things), and Big Data. In addition, it was possible to identify fields with high investment of efforts by the scientific community such as the union between lean production and industry 4.0, production-centered CPS (CPPS), IoT (Industrial Internet of Things - IIoT), among others. The overlapping map showed an increase in the number of keywords from 338 to 1231 over the period of data. The map of scientific developments supported by an exhaustive research, it was possible to show the state of the art, the main challenges and perspectives for future research in the field of industry 4.0 such as Technology, Collaboration/Integration, Management and Implementation.     

System improvements and new experiments in the Advanced Test Reactor, Idaho National Engineering and Environmental Laboratory

The Test Reactor Area (TRA) located at the US Department of Energy's Idaho National Engineering and Environmental Laboratory (INEEL) was a cornerstone in the development of nuclear technologies during the last half of the 20th century. The INEEL's Advanced Test Reactor (ATR), the third generation of test reactors at the TRA, has base programs planned for the first half of the 21st century. As the role of nuclear technologies unfolds in the coming decades, past and future testing at the ATR will continue to contribute to technical, operational, and public issues facing the industry. System improvements have been completed or planned that will support operation of the ATR for many more decades. Optimal use of the past and future experience base will provide opportunities for continual improvement in reactor operations and performance. New programs at the ATR support plant aging studies for several international sponsors, disposition of excess weapons grade plutonium in MOX fuel, development of proliferation resistant fuels, and increased isotope production.