Networks of nanoscale objects are the subject of increasing interest as resistive switching systems for the fabrication of neuromorphic computing architectures. Nanostructured films of bare gold ...clusters produced in gas phase with thickness well beyond the electrical percolation threshold, show a non-ohmic electrical behavior and resistive switching, resulting in groups of current spikes with irregular temporal organization. Here we report the systematic characterization of the temporal correlations between single spikes and spiking rate power spectrum of nanostructured Au two-terminal devices consisting of a cluster-assembled film deposited between two planar electrodes. By varying the nanostructured film thickness we fabricated two different classes of devices with high and low initial resistance respectively. We show that the switching dynamics can be described by a power law distribution in low resistance devices whereas a bi-exponential behavior is observed in the high resistance ones. The measured resistance of cluster-assembled films shows a 1 f scaling behavior in the range of analyzed frequencies. Our results suggest the possibility of using cluster-assembled Au films as components for neuromorphic systems where a certain degree of stochasticity is required.
Mineral dust aerosol (dust) is widely recognized as a fundamental component of the climate system and is closely coupled with glacial-interglacial climate oscillations of the Quaternary period. ...However, the direct impact of dust on the energy balance of the Earth system remains poorly quantified, mainly because of uncertainties in dust radiative properties, which vary greatly over space and time. Here we provide the first direct measurements of the aerosol optical thickness of dust particles windblown to central East Antarctica (Dome C) during the last glacial maximum (LGM) and the Holocene. By applying the Single Particle Extinction and Scattering (SPES) technique and imposing preferential orientation to particles, we derive information on shape from samples of a few thousands of particles. These results highlight that clear shape variations occurring within a few years are hidden to routine measurement techniques. With this novel measurement method the optical properties of airborne dust can be directly measured from ice core samples, and can be used as input into climate model simulations. Based on simulations with an Earth System Model we suggest an effect of particle non-sphericity on dust aerosol optical depth (AOD) of about 30% compared to spheres, and differences in the order of ~10% when considering different combinations of particles shapes.
This is a short review of the detectors based on the superheated liquid techniques, including continuously sensitive bubble chambers, superheated droplet detectors (SDD) and Geysers.
The MOSCAB experiment (Materia OSCura A Bolle) uses the “geyser technique”, a variant of the superheated liquid technique of extreme simplicity. Operating principles of the new dark matter detector ...and technical solutions of the device are reported in detail. First results obtained in a series of test runs taken in laboratory demonstrate that we have successfully built and tested a geyser-concept bubble chamber that can be used in particle physics, especially in dark matter searches, and that we are ready to move underground for extensive data taking.
The Advanced GAmma Tracking Array (AGATA) multidetector spectrometer will provide precise information for the study of the properties of the exotic nuclear matter (very unbalanced proton (Z) and ...neutron (N) numbers) along proton- and neutron-drip lines and of super-heavy nuclei. This is done using the latest technology of particle accelerators. The AGATA spectrometer consists of 180 high-purity germanium detectors. Each detector is segmented into 38 segments. The very harsh project requirements are to measure gamma-ray energies with very high resolution (<inline-formula> <tex-math notation="LaTeX"> < 1\times 10^{-3} </tex-math></inline-formula>) at a high detector counting rate (50 K events/s/crystal). This results in a very high data transfer rate per crystal (5-8 Gb/s). The 38 segments are sampled at 100 MHz with 14 bits of resolution. The samples are continuously transferred to the control and processing (CAP) module, which reduces the data rate from 64 to 5 Gb/s. The CAP module also adds continuous monitoring data, which results in total outgoing data rate of 10 Gb/s. The serial transfer acquisition and readout over Ethernet (STARE) module is designed to fit between the CAP module and the computer farm. It will package the data from the CAP module and transmit it to the server farm using a 10-Gb/s user datagram protocol (UDP) connection with a delivery insurance mechanism implemented to ensure that all data are transferred.
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