Evolution of solar granulation fields from THEMIS-IPM time series

The temporal evolution of solar granulation has been investigated using a time series of high spatial and spectral resolution images acquired at the THEMIS solar telescope (Observatorio del Teide, Tenerife) using the IPM observing mode. In order to investigate different physical properties of solar granulation (associated horizontal velocity fields, lifetimes, intensity and geometry evolution), we identify and track solar granules automatically. We discuss the obtained results and compare them with results reported inthe literature. In order to overcome problems of atmospheric distortions, we also implement a FORTRAN95 code for the application of the Phase Diversity technique that is planned to be used at the THEMIS telescope

Kinematics and Magnetic Properties of a Light Bridge in a Decaying Sunspot

We present the results obtained by analyzing high spatial and spectral resolution data of the solar photosphere acquired by the CRisp Imaging SpectroPolarimeter at the Swedish Solar Telescope on 6 August 2011, relevant to a large sunspot with a light bridge (LB) observed in NOAA AR 11263. These data are complemented by simultaneous Hinode Spectropolarimeter (SP) observation in the Fe I 630.15 nm and 630.25 nm lines. The continuum intensity map shows a discontinuity of the radial distribution of the penumbral filaments in correspondence with the LB, which shows a dark lane (about 0.3" wide and about 8.0" long) along its main axis. The available data were inverted with the Stokes Inversion based on Response functions (SIR) code and physical parameters maps were obtained. The line-of-sight (LOS) velocity of the plasma along the LB derived from the Doppler effect shows motions towards and away from the observer up to 0.6 km/s, which are lower in value than the LOS velocities observed in the neighbouring penumbral filaments. The noteworthy result is that we find motions toward the observer up to 0.6 km/s in the dark lane where the LB is located between two umbral cores, while the LOS velocity motion toward the observer is strongly reduced where the LB is located between an umbral core at one side and penumbral filaments on the other side. Statistically, the LOS velocities correspond to upflows/downflows andcomparing these results with Hinode/SP data, we conclude that the surrounding magnetic field configuration (whether more or less inclined) could have a role in maintaining the conditions for the process of plasma piling up along the dark lane. The results obtained from our study support and confirm outcomes of recent magnetohydro-dynamic simulations showing upflows along the main axis of a LBs

UMTS rapid response real-time seismic networks: implementation and strategies at INGV

The benefits of portable real-time seismic networks are several and well known. During the management of a temporary experiment from the real-time data it is possible to detect and fix rapidly problems with power supply, time synchronization, disk failures and, most important, seismic signal quality degradation due to unexpected noise sources or sensor alignment/tampering. This usually minimizes field maintenance trips and maximizes both the quantity and the quality of the acquired data. When the area of the temporary experiment is not well monitored by the local permanent network, the real-time data from the temporary experiment can be fed to the permanent network monitoring system improving greatly both the real-time hypocentral locations and the final revised bulletin. All these benefits apply also in case of seismic crises when rapid deployment stations can significantly contribute to the aftershock analysis. Nowadays data transmission using meshed radio networks or satellite systems is not a big technological problem for a permanent seismic network where each site is optimized for the device power consumption and is usually installed by properly specialized technicians that can configure transmission devices and align antennas. This is not usually practical for temporary networks and especially for rapid response networks where the installation time is the main concern. These difficulties are substantially lowered using the now widespread UMTS technology for data transmission. A small (but sometimes power hungry) properly configured device with an omnidirectional antenna must be added to the station assembly. All setups are usually configured before deployment and this allows for an easy installation also by untrained personnel. We describe here the implementation of a UMTS based portable seismic network for both temporary experiments and rapid response applications developed at INGV. The first field experimentation of this approach dates back to the 2009 L’Aquila aftershock sequence and since then it has been customized and refined to overcome most reliability and security issues using an industry standard VPN architecture that allows to avoid UMTS provider firewall problems and does not expose to the Internet the usually weak and attack prone data acquisition ports. With this approach all the devices are protected inside a local network and the only exposed port is the VPN server one. This solution improves both the security and the bandwidth available to data transmission. While most of the experimentation has been carried out using the RefTek units of the INGV Mobile Network this solution applies equally well to most seismic data loggers available on the market. Overall the UMTS data transmission has been used in most temporary seismic experiments and in all seismic emergencies happened in Italy since 2010 and has proved to be a very cost effective approach with real-time data acquisition rates usually greater than 97% and all the benefits that result from the fast integration of the temporary data in the National Network monitoring system and in the EIDA data bank

UMTS rapid response real-time seismic networks: implementation and strategies at INGV

<abstract> <p>Universal Mobile Telecommunications System (UMTS) and its evolutions are nowadays the most affordable and widespread data communication infrastructure available almost world wide. Moreover the always growing cellular phone market is pushing the development of new devices with higher performances and lower power consumption. All these characteristics make UMTS really useful for the implementation of an â easy to deployâ temporary real-time seismic station. Despite these remarkable features, there are many drawbacks that must be properly taken in account to effectively transmit the seismic data: Internet security, signal and service availability, power consumption. <list list-type="bullet"><list-item> <p>Internet security: exposing seismological data services and seismic stations to the Internet is dangerous, attack prone and can lead to downtimes in the services, so we setup a dedicated Virtual Private Network (VPN) service to protect all the connected devices.</p></list-item><list-item> <p>Signal and service availability: while for temporary experiment a carefull planning and an accurate site selection can minimize the problem, this is not always the case with rapid response networks. Moreover, as with any other leased line, the availability of the UMTS service during a seismic crisis is basically unpredictable. Nowadays in Italy during a major national emergency a Committee of the Italian Civil Defense ensures unified management and coordination of emergency activities. Inside it the telecom companies are committed to give support to the crisis management improving the standards in their communication networks.</p></list-item><list-item> <p>Power consumption: it is at least of the order of that of the seismic station and, being related to data flow and signal quality is largely unpredictable. While the most secure option consists in adding a second independent solar power supply to the seismic station, this is not always a very convenient solution since it doubles the cost and doubles the equipment on site. We found that an acceptable trade-off is to add an inexpensive Low Voltage Disconnect (LVD) circuit to the UMTS router power supply that switches off the data transmission when the power is low. This greatly reduces the probability of data loss but lowers the real-time data availabilty. This approach guarantees on the average a satisfactory data acquistion rate, only in very few cases and when the real-time data is extremely important for a particular site we needed to double the power supply on the site.</p></list-item></list></p> <p>Overall the UMTS data transmission has been used in most temporary seismic experiments and in all seismic emergencies happened in Italy since 2010 and has proved to be a very cost effective approach with real-time data acquisition rates usually greater than 97â ¯% and all the benefits that result from the fast integration of the temporary data in the National Network monitoring system and in the EIDA data bank.</p> </abstract

UMTS rapid response real-time seismic networks: implementation and strategies at INGV

The benefits of portable real-time seismic networks are several and well known. During the management of a temporary experiment from the realtime data it is possible to detect and fix rapidly problems with power supply, time synchronization, disk failures and, most important, seismic signal quality degradation due to unexpected noise sources or sensor alignment/tampering. This usually minimizes field maintenance trips and maximizes both the quantity and the quality of the acquired data. When the area of the temporary experiment is not well monitored by the local permanent network, the real-time data from the temporary experiment can be fed to the permanent network monitoring system improving greatly both the real-time hypocentral locations and the final revised bulletin. All these benefits apply also in case of seismic crises when rapid deployment stations can significantly contribute to the aftershock analysis. Nowadays data transmission using meshed radio networks or satellite systems is not a big technological problem for a permanent seismic network where each site is optimized for the device power consumption and is usually installed by properly specialized technicians that can configure transmission devices and align antennas. This is not usually practical for temporary networks and especially for rapid response networks where the installation time is the main concern. These difficulties are substantially lowered using the now widespread UMTS technology for data transmission. A small (but sometimes power hungry) properly configured device with an omnidirectional antenna must be added to the station assembly. All setups are usually configured before deployment and this allows for an easy installation also by untrained personnel

Emergenza sismica nel Frusinate (Ottobre 2009 – Gennaio 2010): l’intervento della Rete Sismica Mobile stand-alone e l’analisi dati

Tra il 30 settembre ed il 22 ottobre del 2009 una piccola area della provincia di Frosinone, presso la località di Campoli Appennino, non lontana dalla città di Sora e dal confine con l’Abruzzo, è stata interessata da uno sciame sismico la cui fase più intensa è stata raggiunta nella notte tra il 7 e l’8 di ottobre con due scosse di magnitudo locale (ML) 3.6 e 3.4. Nei primi 23 giorni della sequenza (30 settembre – 22 ottobre) sono state registrate ben 1075 scosse, tutte con magnitudo non superiore a 3.6. In precedenza, nei mesi di maggio e giugno del 2009, si era attivata una piccola area posta ad una quindicina di chilometri a NW di Campoli Appennino, esattamente nella zona montuosa che separa la Val Roveto dalla Vallelonga in territorio abruzzese. Questo piccolo sciame è stato caratterizzato da 64 eventi con ML non superiore a 2.7. Diverse sono state le ragioni che hanno indotto il team scientifico alla guida della Rete Sismica Mobile della sede di Roma [Re.Mo., Moretti et al., 2010a] a disporre nei primi giorni del mese di ottobre un intervento di emergenza nell’area che include i comuni di Sora, Atina, San Donato in Val Comino e Pescasseroli tra le provincie di Frosinone e de L’Aquila: 1) la relativa vicinanza delle due zone epicentrali sopra descritte alla regione dell’Aquilano colpita solo pochi mesi prima dal forte evento sismico del 6 aprile 2009 (ML 5.8, MW 6.31) [Chiarabba et al., 2009; Margheriti et al., 2010], 2) l’emotività della popolazione originatasi a seguito del forte trauma vissuto e 3) non ultimo la psicosi collettiva notevolmente alimentata dai media locali e nazionali. In tutto, sono state installate 4 stazioni sismiche temporanee ad integrazione delle permanenti già presenti in area epicentrale al fine di migliorarne il monitoraggio. In questo lavoro viene presentato l’intervento della Re.Mo. riportando le motivazioni che lo hanno guidato e la tempistica delle operazioni svolte. Inoltre, verrà fornita una breve descrizione delle caratteristiche geologico-strutturali e sismotettoniche dell’area e saranno mostrate alcune analisi eseguite sui dati acquisiti in campagna

Experimental evaluation of the thermal polarization in direct contact membrane distillation using electrospun nanofiber membranes doped with molecular probes

Membrane distillation (MD) has recently gained considerable attention as a valid process for the production of fresh-water due to its ability to exploit low grade waste heat for operation and to ensure a nearly feed concentration-independent production of high-purity distillate. Limitations have been related to polarization phenomena negatively affecting the thermal efficiency of the process and, as a consequence, its productivity. Several theoretical models have been developed to predict the impact of the operating conditions of the process on the thermal polarization, but there is a lack of experimental validation. In this study, electrospun nanofiber membranes (ENMs) made of Poly(vinylidene fluoride) (PVDF) and doped with (1, 10-phenanthroline) ruthenium (II) Ru(phen) 3 were tested at different operating conditions (i.e., temperature and velocity of the feed) in direct contact membrane distillation (DCMD). The temperature sensitive luminophore, Ru(phen) 3 , allowed the on-line and non-invasive mapping of the temperature at the membrane surface during the process and the experimental evaluation of the effect of the temperature and velocity of the feed on the thermal polarization