•THz radiation from CFMS/HM bilayers shows tunability by magnetic field and temperature.•Difference of THz transients from CFMS/Pt and CFMS/Ta points to role of the interface.•The efficiency of THz ...emission from the spintronic emitters is affected by several parameters.•Including strength of SOC, spin diffusion length, thickness of layers and interface transmission.
We generated pulses of electromagnetic radiation with a frequency content up to three terahertz (THz) by optical excitation of Co2Fe0.4Mn0.6Si Heusler alloy/heavy metal bilayers (CFMS/HM) using fs-laser pulses. We attribute the generation process to the conversion of a spin current, generated by the illumination with a fs-laser pulse, to a charge current via the inverse spin Hall effect. We compared the THz emission efficiency in CFMS/Pt and CFMS/Ta bilayers due to their high spin–orbit coupling of Pt and Ta. Surprisingly, our data reveal that CFMS/Pt shows substantially larger THz amplitudes compared to CFMS/Ta. Both bilayers exhibit a tunability of the THz amplitude by external magnetic field both at 300 K and 100 K. Ferromagnetic resonance measurements demonstrate that CFMS/Ta has a high effective spin mixing conductance, describing the efficiency of interfacial spin transport. We observe that the efficiency of the THz radiation cannot be solely described by the spin–orbit coupling strength and the spin diffusion length in the HM material plays an important role.
► A contribution to estimate wind farm aggregated power output distributions is presented. ► The consideration of independence of wind speed at different locations is avoided. ► Correlation between ...wind speeds at different locations is taken into account. ► Kernel estimators are used. ► The case study includes results under different assumptions with regards to correlation.
In this contribution we present an approach to the estimation of aggregated power output distribution from wind farms, with a focus on the alternative simulating model of correlated wind speeds and kernel estimators which overcomes some disadvantages of related ones. The case study shows the application of the approach under assumptions concerning relationships between wind speeds at different generation sites.
We present an overview of the state-of-the-art of NbN superconducting single-photon detectors (SSPDs). Our devices exhibit quantum efficiency (QE) of up to 30% in near-infrared wavelength and 0.4% at ...5 mum, with a dark-count rate that can be as low as 10 -4 s -1 . The SSPD structures integrated with lambda/4 microcavities achieve a QE of 60% at telecommunication, 1550-nm wavelength. We have also developed a new generation of SSPDs that possess the QE of large-active-area devices, but, simultaneously, are characterized by low kinetic inductance that allows achieving short response times and the GHz-counting rate with picosecond timing jitter. The improvements presented in the SSPD development, such as fiber-coupled SSPDs, make our detectors most attractive for high-speed quantum communications and quantum computing.
Food composition databases prepared for nutrition labelling have some important differences to other food composition databases. Nutrient values must be expressed in accordance with legal ...requirements for nutrition labelling in the country where it will be used. The database should include all the nutrients that must be declared in labels and contain data for ingredients (including additives) used in manufacturing. Data should be as current as possible and it may be necessary to update the databases before release. Information on typical measures, indicative weight changes during processing and retention factors (if including vitamins and minerals) will be required, as will explanatory material appropriate to the audience. Challenge areas for use of a labelling database include foods prepared by soaking or packing in salt or by deep frying, and estimation of vitamin levels. Limited Australian and New Zealand research suggests that label and analytical data for proximate nutrients, fatty acids and sodium agree in around 60% of cases or more; for added micronutrients, no more than 50% of values agree. However there is no research available to show whether labels prepared from a labelling database are more or less accurate than labels prepared using analysis. The Australian experience shows that it is possible to develop a labelling database suitable for many, but not all, foods and nutrients, but there is a lack of information to assess the quality of the data produced.
During the last decade, research on nanowires as superconducting single-photon detectors (SNSPDs or SSPDs) has gained interest due to many experiments demonstrating their fascinating potentialities ...in several fields. The search for more appealing materials for SNSPDs is presently a hot topic. Several superconductors have been proposed as possible alternatives to NbN, which is presently the racehorse. Examples are WSi and MoSi, which have advantages such as amorphous morphology and narrow-gap and low quasi-particle diffusivity, which permits extending the application in the mid- and far-IR ranges. A strategy based on material hybridization of superconductors with ferromagnets can open a new direction in the development of SNSPD. We present results concerning the hybrid superconducting/ferromagnetic (S/F) single nanowires for SNSPDs. Experiments under laser illumination show a single-photon response of S/F-based nanowires. The ferromagnetic overlayer has the beneficial effect of an increase of the superconducting critical current density and a decrease of dark counts. We compare dark counts in hybrid S/F with pure S nanowires. The experimental results are explained in terms of the existing models based on the presence of magnetic vortices.
Traumatic brain injuries (TBIs) are common with an estimated 27.1 million cases per year. Approximately 80% of TBIs are categorized as mild TBI (mTBI) based on initial symptom presentation. While in ...most individuals, symptoms resolve within days to weeks, in some, symptoms become chronic. Advanced neuroimaging has the potential to characterize brain morphometric, microstructural, biochemical, and metabolic abnormalities following mTBI. However, translational studies are needed for the interpretation of neuroimaging findings in humans with respect to the underlying pathophysiological processes, and, ultimately, for developing novel and more targeted treatment options. In this review, we introduce the most commonly used animal models for the study of mTBI. We then summarize the neuroimaging findings in humans and animals after mTBI and, wherever applicable, the translational aspects of studies available today. Finally, we highlight the importance of translational approaches and outline future perspectives in the field of translational neuroimaging in mTBI.
We have fabricated and characterized ultrafast metal-semiconductor-metal (MSM) photodetectors with recessed electrodes, based on low-temperature-grown GaAs. The new recessed-electrode MSM geometry ...led to an improved electric-field distribution inside the photodetector structure and resulted in a 25% breakdown voltage and sensitivity increase with simultaneous four-fold reduction of capacitance, as compared to the identical MSM devices with planar electrodes. Time-resolved studies performed using 100-fs-duration laser pulses showed that recessed-electrode MSMs exhibited 1.0-ps-wide photoresponse transients with no slow after-pulse tails and their photoresponse time was 0.9 ps. The improved transient photoresponse parameters are the main advantages of the recessed-electrode geometry.
We demonstrate low-temperature (LT)-grown GaAs photodetectors transferred on flexible polyethylene terephthalate (PET) plastic substrates. The LT-GaAs layer was patterned into 20×20 μm 2 chips, which ...after placing on the PET substrates were integrated with coplanar strip transmission lines. The devices exhibit low dark currents (/spl les/2×10/sup -8/ A), subpicosecond photoresponse time, and signal amplitudes up to /spl sim/0.9 V at the bias voltage of /spl les/80 V and under laser beam excitation power of /spl les/8 mW at 810-nm wavelength. At the highest bias (/spl sim/80 V) level, an increase of the response time (up to 1.3 ps) was observed and attributed to the influence of heating effects due to low thermal conductivity of PET. Our LT-GaAs-on-PET photodetectors withstand hundredfold mechanical bending of the substrate and are intended for applications in hybrid optoelectronic circuits fabricated on noncrystalline substrates, in terahertz imaging, and in biology-related current-excitation tests.
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