Survey on communication architectures for wind energy integration with the smart grid

Communication systems are needed to integrate generated power from wind farms with the electrical grid. This paper provides a comprehensive review of available communication technologies, protocols and objectives related to wind energy and electrical grid integration. This paper summarizes the communication system solutions for wind generation. A major obstacle is an absence of unified communication architectures and standards.     

On the origin of decay of spin current with temperature in organic spintronic devices

This article addresses the most challenging question facing the organic spintronics community today – what causes the universal loss of Giant Magnetoresistance (GMR) signal in organic spin valve devices made with different spin-polarized electrodes and organic semiconductor spacers? Careful analysis of our own and other experimental results available in literature indicate that transition of transport from polaron tunneling limit (suggested by the variable range hopping model) to thermally activated hopping limit (in the temperature range of 40–58 K) marks the most significant decrease of spin relaxation in organic semiconductors. With increasing occupancy of the available hopping sites by the thermally activated carriers, chances of spin flip inside the organic semiconductors increases significantly causing fast spin relaxation in the spin-valves.     

Electrode Dependence of Tunneling Electroresistance and Switching Stability in Organic Ferroelectric P(VDF‐TrFE)‐Based Tunnel Junctions

Ferroelectric tunnel junctions (FTJs) are promising candidates for nonvolatile memories and memristor‐based computing circuits. Thus far, most research has focused on FTJs with a perovskite oxide ferroelectric tunnel barrier. As the need for high‐temperature epitaxial film growth challenges the technological application of such inorganic junctions, more easily processable organic ferroelectrics can serve as alternative if large tunneling electroresistance (TER) and good switching durability would persist. This study reports on the performance of FTJs with a spin‐coated ferroelectric P(VDF‐TrFE) copolymer tunnel barrier. The use of three different bottom electrodes, indium tin oxide (ITO), La_0.67Sr_0.33MnO₃, (LSMO), and Nb‐doped SrTiO₃ (STO) are compared and it is shown that the polarity and magnitude of the TER effect depend on their conductivity. The largest TER of up to 10⁷% at room temperature is measured on FTJs with a semiconducting Nb‐doped STO electrode. This large switching effect is attributed to the formation of an extra barrier over the space charge region in the substrate. The organic FTJs exhibit good resistance retention and switching endurance up to 380 K, which is just below the ferroelectric Curie temperature of the P(VDF‐TrFE) barrier.     

Fortress Abstractions in X10 Framework

International Journal of Parallel Programming - Fortress provides a nice set of abstractions used widely in scientific computing. The use of such abstractions enhances the productivity of...     

Comparative Study of Persistent Photo-Induced Magnetization in Low and Intermediate Bandwidth Manganite Thin Films

This article presents a comparative study of persistent photo-induced magnetization in intermediate and low bandwidth perovskite manganite thin films, and analyzes the possible mechanisms for the observed differences in light of their structural and magnetic properties. Intermediate bandwidth manganite La_0.9Ca_0.1MnO₃ (LCMO) and low bandwidth manganite Pr_0.9Ca_0.1MnO₃ (PCMO), both show persistent change in magnetization under light. However, under illumination, while LCMO shows increased ferromagnetic (FM) interaction both in low and saturation field regime, PCMO shows increased FM interaction at low fields and decreased FM behavior near saturation fields. Also relaxation of photo-induced magnetization shows stretched exponential nature in LCMO compared to much faster relaxation, beyond detection limit in PCMO. Comparison between these two systems will provide important insight of the underlying physics of persistent photo-induced magnetization of perovskites manganites and will consequently facilitate their application in magneto-optical devices, photodiodes and photovoltaics.     

Monitoring quality attributes for high-shear wet granulation with audible acoustic emissions

Continuing development of process analytical technology (PAT) tools is needed in the pharmaceutical industry to provide more flexible processing and achieve products of consistent quality. For high-shear wet granulation, audible acoustic emissions (AAEs) have shown potential as a PAT tool for monitoring changes in physical properties related to product quality. This article develops the relationship between AAEs and two critical quality attributes, size and density, and investigates the potential for monitoring product quality online. Condenser microphones were placed inside the air exhaust of a PMA-10 high-shear granulator to collect AAEs for a design of experiment (DOE) where particle size and density were varied by changing the grade of Avicel in the formulation. The results showed increases in particle size and density affect the observed decreases in the AAEs at granulation end-point and during over wetting. In addition, the changes in size and density could be represented by different combinations of 10 Hz frequency groups and the trends in the multivariate scores support online monitoring.     

Photoinduced Colossal Magnetoresistance under Substantially Reduced Magnetic Field

The colossal magnetoresistive insulator to metal switching of almost nine orders of magnitude under the significantly reduced magnetic field is achieved by illumination for the low bandwidth manganite thin films. Similarly, by changing the measuring bias voltage through the sample the required magnetic field for insulator–metal transition can be further fine‐tuned. By applying a magnetic field of suitable strength, the samples can also be tuned to be extra sensitive to the illumination having colossal effect on the resistivity at low temperatures. This kind of utilizing of multiple external stimulants, which together change the properties of the material, could have significant impact on the new generation of phase‐change memories working under affordable conditions.     

Analysis of Water Quantity and Quality Trade-Offs to Inform Selective Harvesting of Inflows in Complex Water Resource Systems

Water Resources Management - Challenges faced by water resource systems are multi-faceted. The problem can be even more pronounced in a dry continent like Australia where the water resources can...