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We provide a novel methodological approach to the estimate of the change of the Quantum Vacuum electromagnetic energy density in a High critical Temperature superconducting metal bulk sample, when it undergoes the transition in temperature, from the superconducting to the normal phase. The various contributions to the Casimir energy in the two phases are highlighted and compared. While the TM polarization of the vacuum mode allows for a macroscopic description of the superconducting transition, the changes in the TE vacuum mode induced by the superconductive correlations are introduced within a microscopic model, which does not explicitly take into account the anisotropic structure of the material., 20 pages, 13 figures, to be published in Phys.Rev. B

We present a multiple test for the targeted search of continuous gravitational waves from an ensemble of known pulsars, combining multidetector single pulsar statistics defined through the 5n-vector method. In order to maximize the detection probability, we describe a rank truncation method to select the most promising sources within the ensemble, based on the p-values computed for single pulsar analysis. To test the efficiency of our method, we use a Monte Carlo procedure and define a p-value for the ensemble that is an overall p-value for the hypothesis of continuous wave emissions from a set of known pulsars. We also perform a pilot search on real data from the O3A dataset of the two LIGO detectors.

It is expected that noise produced by terrestrial gravity fluctuations will start to limit the sensitivity of the ground-based, gravitational-wave detector Virgo in coming observation runs. A system is under preparation at Virgo to cancel this noise, also known as Newtonian noise. This Newtonian noise cancelation system requires the deployment of seismometer arrays inside the Virgo buildings. Crucial for the design of such a system is a detailed understanding of correlations between ground vibrations and Virgo’s gravitational waves detector data. In this article, we present first analyses of such correlations observed with a tiltmeter. We find that revealed correlations are stronger than predicted by possible pure gravitational coupling, which is pointing towards additional coupling mechanisms. These findings might impact the design of the Newtonian noise cancelation system if the additional couplings cannot be mitigated.

In this paper we study the Casimir energy of a sample made by N cavities, with $$N\gg 1$$ N ≫ 1 , across the transition from the metallic to the superconducting phase of the constituting plates. After having characterised the energy for the configuration in which the layers constituting the cavities are made by dielectric and for the configuration in which the layers are made by plasma sheets, we concentrate our analysis on the latter. It represents the final step towards the macroscopical characterisation of a “multi-cavity” (with N large) necessary to fully understand the behaviour of the Casimir energy of a YBCO (or a GdBCO) sample across the transition. Our analysis is especially useful to the Archimedes experiment, aimed at measuring the interaction of the electromagnetic vacuum energy with a gravitational field. To this purpose, we aim at modulating the Casimir energy of a layered structure, the multi-cavity, by inducing a transition from the metallic to the superconducting phase. After having characterised the Casimir energy of such a structure for both the metallic and the superconducting phase, we give an estimate of the modulation of the energy across the transition.

The Einstein Telescope (ET) is a proposed third-generation gravitational-wave (GW) underground observatory. It will have greatly increased sensitivity compared to current GW detectors, and it is designed to extend the observation band down to a few Hz. At these frequencies, a major limitation of the ET sensitivity is predicted to be due to gravitational fluctuations produced by the environment, most importantly by the seismic field, which give rise to the so-called Newtonian noise (NN). Accurate models of ET NN are crucial to assess the compatibility of an ET candidate site with the ET sensitivity target also considering a possible reduction of NN by noise cancellation. With NN models becoming increasingly complex as they include details of geology and topography, it is crucial to have tools to make robust assessments of their accuracy. For this purpose, we derive a lower bound on seismic NN spectra, which is weakly dependent on geology and properties of the seismic field. As a first application, we use the lower limit to compare it with NN estimates recently calculated for the Sardinia and Euregio Meuse-Rhine (EMR) candidate sites. We find the utility of the method, which shows an inconsistency with the predictions for the EMR site, which indicates that ET NN models require further improvement., 16 pages, 4 figures, 2 tables

Fluctuations of gravitational forces cause so-called Newtonian noise (NN) in gravitational-wave (GW) detectors which is expected to limit their low-frequency sensitivity in upcoming observing runs. Seismic NN is produced by seismic waves passing near a detector's suspended test masses. It is predicted to be the strongest contribution to NN. Modeling this contribution accurately is a major challenge. Arrays of seismometers were deployed at the Virgo site to characterize the seismic field near the four test masses. In this paper, we present results of a spectral analysis of the array data from one of Virgo's end buildings to identify dominant modes of the seismic field. Some of the modes can be associated with known seismic sources. Analyzing the modes over a range of frequencies, we provide a dispersion curve of Rayleigh waves. We find that the Rayleigh speed in the NN frequency band 10 Hz - 20 Hz is very low ($\lesssim$100\,m/s), which has important consequences for Virgo's seismic NN. Using the new speed estimate, we find that the recess formed under the suspended test masses by a basement level at the end buildings leads to a 10 fold reduction of seismic NN., Comment: This draft has been approved through LIGO and VIRGO review process

The recent discovery of gravitational waves (GWs) and their potential for cosmic observations prompted the design of the future third-generation GW interferometers, able to extend the observation distance for sources up to the frontier of the Universe. In particular, the European detector Einstein Telescope (ET) has been proposed to reach peak strain sensitivities of about 3×10−25 Hz−1/2 in the 100 Hz frequency region and to extend the detection band down to 1 Hz. In the bandwidth [1,10] Hz, the seismic ambient noise is expected to represent the major perturbation to interferometric measurements, and the site that will host the future detectors must fulfill stringent requirements on seismic disturbances. In this article, we conduct a seismological study at the Italian ET candidate site, the dismissed mine of Sos Enattos in Sardinia. In the range between few mHz to hundreds of mHz, out of the detection bandwidth for ET, the seismic noise is compatible with the new low-noise model (Peterson, 1993); in the [0.1,1] Hz bandwidth, we found that seismic noise is correlated with sea wave height in the northwestern Mediterranean Sea. In the [1,10] Hz frequency band, noise is mainly due to anthropic activities; within the mine tunnels (≃100 m underground), its spectrum is compliant with the requirements of the ET design. Noise amplitude decay with depth is consistent with a dominance of Rayleigh waves, as suggested by synthetic seismograms calculated for a realistic velocity structure obtained from the inversion of phase- and group-velocity dispersion data from array recording of a mine blasting. Further investigations are planned for a quantitative assessment of the principal noise sources and their spatiotemporal variations.

We report the tilt sensitivity reached by the ARCHIMEDES tiltmeter in the 2–20 Hz frequency region, where seismic noise is expected to give an important limitation to the sensitivity in the next future Gravitational Waves detection, particularly through Newtonian noise. The tilt noise level $$\tilde{\theta }(f)$$ θ ~ ( f ) is about $$10^{-12} \mathrm{rad}/\sqrt{\mathrm{Hz}}$$ 10 - 12 rad / Hz in most of the band, reaching the minimum of $$\tilde{\theta } = 7\cdot 10^{-13} \mathrm{rad}/\sqrt{\mathrm{Hz}}$$ θ ~ = 7 · 10 - 13 rad / Hz around 9 Hz. The tiltmeter is a beam balance with a 0.5 m suspended arm and interferometric optical readout, working in closed loop. The results have been obtained by a direct measurement of the ground tilt at the Sos Enattos site (Sardinia, Italy). This sensitivity is a requirement to use the tiltmeter as part of an effective Newtonian noise reduction system for present Gravitational Waves detectors, and also confirms that Sos Enattos is among the quietest sites in the world, suitable to host the third-generation Gravitational Waves detector Einstein Telescope.

The first twenty years of operation of gravitational-wave interferometers have shown that these detectors are affected by physical disturbances from the surrounding environment. These are seismic, acoustic, or electromagnetic disturbances that are mainly produced by the experiment infrastructure itself. Ambient noise can limit the interferometer sensitivity or potentially generate transients of non-astrophysical origin. Between 1 April 2019 and 27 March 2020, the network of second generation interferometers&mdash, LIGO, Virgo and GEO&mdash, performed the third joined observing run, named O3, searching for gravitational signals from the deep universe. A thorough investigation has been done on each detector before and during data taking in order to optimize its sensitivity and duty cycle. In this paper, we first revisit typical sources of environmental noise and their coupling paths, and we then describe investigation methods and tools. Finally, we illustrate applications of these methods in the hunt for environmental noise at the Virgo interferometer during the O3 run and its preparation phase. In particular, we highlight investigation techniques that might be useful for the next observing runs and the future generation of terrestrial interferometers.

International audience; We present the status of the art of the Archimedes experiment, devoted to measuring the debated interaction of quantum vacuum fluctuations and gravity. The method is essentially the weighing of the transition energy of a layered superconductor where the contribution of vacuum energy to the transition energy is expected to be relevant. The transition is obtained by modulating the temperature of the superconducting sample at a frequency of about 10 mHz and the expected change of weight is measured with a suitably designed high sensitivity cryogenic beam balance. In this paper, we present an overview of the experiment, discussing the expected signal to be measured, and presenting in particular the result of a prototype balance operated in our present laboratory. In the frequency range of the measurement, the sensitivity is affected mainly by seismic, thermal, sensor, and control noise. We discuss these points showing in particular the design of the cryogenic apparatus, the final balance, and the quiet seismic site that will host the final measurement.

How animals integrate different sensory information for orientation is a complex process involving interactions between a variety of internal and external factors. Due to this complexity, each component of a suite of factors is typically studied in isolation. Here, we examine how an internal factor (personality of fish) influences the response of zebrafish (Danio rerio) to the magnetic field, while swimming in a flow chamber. Our previous work demonstrated that the orientation to the water current (rheotaxis) of zebrafish individuals is influenced by variations of the magnetic field only when fish are part of a shoal. In this study, we evaluated the rheotactic behavior of 20 fish, grouped in shoals of “proactive” or “reactive” individuals, under magnetic fields of different directions. We found that the magnetic field influenced at which water speed rheotaxis was elicited in zebrafish with “reactive” personality, but not in those with “proactive” personality. These results suggest that fish personality influences response to or weighing of sensory inputs and provides some insight on the variation in behavioral responses to environmental stimuli in both laboratory and natural settings.

To orient themselves in their environment, animals integrate a wide array of external cues, which interact with several internal factors, such as personality. Here, we describe a behavioral protocol designed for the study of the influence of zebrafish personality on their orientation response to multiple external environmental cues, specifically water currents and magnetic fields. This protocol aims to understand whether proactive or reactive zebrafish display different rheotactic thresholds (i.e., the flow speed at which the fish start swimming upstream) when the surrounding magnetic field changes its direction. To identify zebrafish with the same personality, fish are introduced in the dark half of a tank connected with a narrow opening to a bright half. Only proactive fish explore the novel, bright environment. Reactive fish do not exit the dark half of the tank. A swimming tunnel with low flow rates is used to determine the rheotactic threshold. We describe two setups to control the magnetic field in the tunnel, in the range of the earth's magnetic field intensity: one that controls the magnetic field along the flow direction (one dimension) and one that allows a three-axial control of the magnetic field. Fish are filmed while experiencing a stepwise increase of the flow speed in the tunnel under different magnetic fields. Data on the orientation behavior are collected through a video-tracking procedure and applied to a logistic model to allow the determination of the rheotactic threshold. We report representative results collected from shoaling zebrafish. Specifically, these demonstrate that only reactive, prudent fish show variations of the rheotactic threshold when the magnetic field varies in its direction, while proactive fish do not respond to magnetic field changes. This methodology can be applied to the study of magnetic sensitivity and rheotactic behavior of many aquatic species, both displaying solitary or shoaling swimming strategies.

We describe a new actuation technique for gravity experiments based on a liquid field mass. The characterizing idea is to modulate the gravity force acting on a test mass by controlling the level of a liquid in a suitable container. This allows to obtain a periodical gravity force without moving parts (except the liquid level) close to the TM. We describe in detail the most relevant aspects of the liquid actuator and discuss how it can be used in gravity experiments. In particular, we analyze an application to test the inverse square law in the mm to cm distance region.

The role of endothelium in the progression of atheromasic disease has already been demonstrated. Endothelin-1 (ET-1) is released from endothelial cells during acute and chronic vascular damage and it appears to be the strongest vasoconstrictor agent known. The aim of this study is to investigate the amount of endothelial damage in patients with unstable angina (UA), as defined by serum levels of ET-1, to verify a possible correlation with increased ischaemic damage by evaluation of serum N-terminal pro-brain natriuretic peptide (NT-proBNP) and interleukin 8 (IL-8) levels. Serum levels of ET-1, IL-8 and NT-proBNP obtained from 10 patients affected by low-risk UA were compared to those belonging to eight healthy subjects. In order to compare the laboratory data pertaining to the two populations, a Student’s t-test and a Mann-Whitney U test were performed. Levels of ET-1, IL-8 and NT-proBNP in samples of peripheral blood of patients affected by UA were significantly elevated, compared with those of the control group. The linear correlation analysis demonstrated a positive and significant correlation between levels of ET-1 and IL-8, between levels of ET-1 and NT-proBNP, and between levels of IL-8 and NT-proBNP in subjects affected by UA. Early elevated levels of ET-1, IL-8 and NT-proBNP in patients with UA show a coexistence between ischaemic insults and endothelial damages. A positive and significant linear correlation between levels of ET-1 and IL-8, between levels of ET-1 and NT-proBNP, and between levels of IL-8 and NT-proBNP confirms that an increased ischaemic insult is correlated to inflammation signs and endothelium damage signs. In patients with UA, ischaemia is always associated with a systemic immuno-mediated activity induced by acute endothelial damage. We suggest early administration of ET-1-selective receptor blockers and anti-inflammatory drugs.

International audience; Archimedes is an experiment devoted to measure the weight of zero point energy by weighing acascade of rigid Casimir cavitities costituted by a layered type II superconductor, when the reflec-tivity of the cavities is modulated and thus the energy inside. In this paper the working principleof the experiment is presented and the results of the existing prototype are presented, showingthe torque sensitivity of about 10−11 Nm/sqrtHz in the region of frequency from about 50 mHzup two 150 mHz. Moreover the major upgrades needed to reach the desired final sensitivity arediscussed.

International audience; Correlated magnetic noise from Schumann resonances threatens to contaminate the observation of a stochastic gravitational-wave background in interferometric detectors. In previous work, we reported on the first effort to eliminate global correlated noise from the Schumann resonances using Wiener filtering, demonstrating as much as a factor of two reduction in the coherence between magnetometers on different continents. In this work, we present results from dedicated magnetometer measurements at the Virgo and KAGRA sites, which are the first results for subtraction using data from gravitational-wave detector sites. We compare these measurements to a growing network of permanent magnetometer stations, including at the LIGO sites. We show the effect of mutual magnetometer attraction, arguing that magnetometers should be placed at least one meter from one another. In addition, for the first time, we show how dedicated measurements by magnetometers near to the interferometers can reduce coherence to a level consistent with uncorrelated noise, making a potential detection of a stochastic gravitational-wave background possible.

In this paper, we compare the effects of different theories of gravitation on the apsidal motion of eccentric eclipsing detached binary stars. The comparison is performed by using the formalism of the post-Newtonian parametrization to calculate the theoretical advance at periastron and compare it to the observed one, after having considered the effects of the structure and rotation of the involved stars. A variance analysis on the results of this comparison shows that no signicant difference can be found due to the effect of the different theories under test with respect to the standard general relativity (GR). It will be possible to observe differences, as we would expect, by checking the observed period variation on a much larger lapse of time.

The recent discovery of merging black holes suggests that a stochastic gravitational-wave background is within reach of the advanced detector network operating at design sensitivity. However, correlated magnetic noise from Schumann resonances threatens to contaminate observation of a stochastic background. In this paper, we report on the first effort to eliminate intercontinental correlated noise from Schumann resonances using Wiener filtering. Using magnetometers as proxies for gravitational-wave detectors, we demonstrate as much as a factor of two reduction in the coherence between magnetometers on different continents. While much work remains to be done, our results constitute a proof-of-principle and motivate follow-up studies with a dedicated array of magnetometers.

In this paper we compare the effects of different theories of gravitation on the apsidal motion of a sample of Eccentric Eclipsing Detached Binary stars. The comparison is performed by using the formalism of the Post-Newtonian parametrization to calculate the theoretical advance at periastron and compare it to the observed one, after having considered the effects of the structure and rotation of the involved stars. A variance analysis on the results of this comparison, shows that no significant difference can be found due to the effect of the different theories under test with respect to the standard General Relativity. It will be possible to observe differences, as we would expect, by checking the observed period variation on a much larger lapse of time. It can also be noticed from our results, that f(R) theory is the nearest to GR with respect to the other tested theories.

In this paper is presented an hybrid algorithm for finding the absolute extreme point of a multimodal scalar function of many variables. The algorithm is suitable when the objective function is expensive to compute, the computation can be affected by noise and/or partial derivatives cannot be calculated. The method used is a genetic modification of a previous algorithm based on the Price’s method. All information about behavior of objective function collected on previous iterates are used to chose new evaluation points. The genetic part of the algorithm is very effective to escape from local attractors of the algorithm and assures convergence in probability to the global optimum. The proposed algorithm has been tested on a large set of multimodal test problems outperforming both the modified Price’s algorithm and classical genetic approach.

A torsion pendulum with 2 soft degrees of freedom (DOF), realized by off-axis cascading two torsion fibers, has been built and operated. This instrument allows simultaneous measurement of force and torque acting on the suspended test mass, approaching free-fall condition down to a few mHz. It was developed for ground testing on two DOFs, before the launch, of the Gravitational Reference Sensor of the LISA-Pathfinder mission. We will report on the results of some measurement campaigns devoted in particular to the characterization of force to torque and torque to force actuation cross-talks. We will also indicate further possible upgrades of the facility for application for ground testing of future space gravitational wave antennas or other space experiments requiring drag-free control.

In this work we present a study of the fabrication of the junction between amorphous and porous silicon. Porous silicon was obtained by electrochemical etching of a 2 μm thick crystalline n-doped layer obtained by thermal recrystallisation of amorphous silicon deposited using chemical vapour deposition (CVD). A thin amorphous silicon emitter and an intrinsic buffer layer was deposited by plasma enhanced chemical vapour deposition (PECVD) to form the heterojunction. Photoluminescence (PL) measurements on porous film before and after heterojunction formation were performed and analysed with a model to determine the porous film properties. Current as a function of voltage was measured on the device which rectified for this kind of heterojunction.

We present a dynamical model for the double torsion pendulum nicknamed PETER, where one torsion pendulum hangs in cascade, but off-axis, from the other. The dynamics of interest in these devices lies around the torsional resonance, that is at very low frequencies (mHz). However, we find that, in order to properly describe the forced motion of the pendulums, also other modes must be considered, namely swinging and bouncing oscillations of the two suspended masses, that resonate at higher frequencies (Hz). Although the system has obviously 6+6 Degrees of Freedom, we find that 8 are sufficient for an accurate description of the observed motion. This model produces reliable estimates of the response to generic external disturbances and actuating forces or torques. In particular, we compute the effect of seismic floor motion (tilt noise) on the low frequency part of the signal spectra and show that it properly accounts for most of the measured low frequency noise., 15 pages, 6 figures

The paper describes the application of a monolithic folded pendulum (FP) as a tiltmeter for geophysical applications, developed at the University of Salerno. Both the theoretical model and the experimental results of a tunable mechanical monolithic FP tiltmeter prototype are presented and discussed. Some of the most important characteristics, like the possibility of tuning its resonance frequency to values as low as 70mHz and its measured resolution of ≈ 0.1 nrad at 100mHz, are detailed. Among the scientific results, earth tilt tides have been already observed with a monolithic FP tiltmeter prototype.

In this paper we present preliminary experimental results relative to the application of open loop monolithic folded pendulum sensors to the control of large band multistage suspensions (seismic attenuators) and inertial platforms in the band 0.01 ± 10Hz. In fact, beyond the obvious compactness and robustness of monolithic implementations of folded pendulum, high sensitivity, large measurement band (10−7 ÷ 100Hz), tunability of the resonance frequency (necessary to adapt the sensors to the mechanics), high sensitive integrated laser optical readout (e.g. optical lever, laser interferometer), and very good immunity to environmental noises are some of the main advantages of this class of sensors. The results are presented and discussed in this paper together with the planned further developments and improvements.

This paper describes a new implementation of monolithic horizontal sensor, developed at the University of Salerno, based on the Folded Pendulum architecture, configurable both as seismometer and as accelerometer. The large low-frequency band (10-6 ÷ 10Hz), the high sensitivity ( in the band 0.1 ÷ 10 Hz) and the high quality factor in air (Q > 1500) are largely better than all the previous Folded Pendulum implementations. Moreover its monolithic implementation of the whole mechanics, coupled with a full tunability of its resonance frequency (70 mHz ÷ 1.2 Hz) obtained with a specially designed calibration procedure and with an integrated laser optical readout, guarantees both compactness, robustness and immunity to environmental noises. This makes this sensor suitable for a large number of scientific applications, also in high vacuum and cryogeny. Applications of this sensor are already started in the field of geophysics, including the study of seismic and newtonian noise for characterization of suitable sites for future underground interferometric detectors of gravitational waves.

This paper describes an optimized version of the mechanical version of the monolithic tunable folded pendulum, developed at the University of Salerno, configurable both as seismometer and, in a force-feedback configuration, as accelerometer. Typical application of the sensors are in the field of geophysics, including the study of seismic and newtonian noise for characterization of suitable sites for underground interferometer for gravitational waves detection. The sensor, shaped with precision machining and electric-discharge-machining, like the previous version, is a very compact instrument, very sensitive in the low-frequency seismic noise band, with a very good immunity to environmental noises. Important characteristics are the tunability of the resonance frequency and the integrated laser optical readout, consisting of an optical lever and an interferometer. The theoretical sensitivity curves, largely improved due to a new design of the pendulum arms and of the electronics, are in a very good agreement with the measurements. The very large measurement band (10 -6 ± 10Hz) is couple to a very good sensitivity (10 -12 m/√ Hz in the band 0.1 ± 10 Hz ), as seismometer. Prototypes of monolithic seismometers are already operational in selected sites around the world both to acquire seismic data for scientific analysis of seismic noise and to collect all the useful information to understand their performances in the very low frequency band (f < 1mHz). The results of the monolithic sensor as accelerometer (force feed-back configuration) are also presented and discussed. Particular relevance has their sensitivity that is better than 10 -11 m/s 2 /√Hz in the band 0.1 ± 10Hz. Finally, hypotheses are made on further developments and improvements of monolithic sensors.

In this paper we present the control system we implemented for test the control of a suspended mass using monolithic tunable folded pendulum sensors in the band 0.01 - 100 Hz. The main goal of this experiment is to test the performances of monolithic sensors as main acceleration sensors for application in inertial damping control systems. The main advantages of these sensors with respect to the others are the sensitivity (better than 10-11 m/s2/√(Hz) in the band 0.1 ÷ 10Hz), the large band (0.01 ÷ 100Hz), the tuneability of the resonance frequency (necessary to match the sensors to the suspension mechanics) and the high sensitive integrated laser optical readout, consisting of an optical lever and an interferometer, and a very good immunity to environmental noises. Preliminary results are presented and discussed in this paper together with the planned further developments and improvements of monolithic sensors.

This paper describes a new mechanical architecture of the monolithic tunable folded pendulum, developed at the University of Salerno, configurable both as seismometer and, in a force-feedback configuration, as accelerometer. Typical applications are the remote monitoring of seismic and newtonian noises for geophysical applications. This sensor, shaped with precision machining and electric-discharge-machining, like the previous versions, is a very compact instrument, very sensitive in the low-frequency seismic noise band, with a very good immunity to environmental noises. Important characteristics are the large band (10-6 - 10mHz), the tunability of the resonance frequency and the laser optical readout, that integrates an optical lever and a laser interferometer. The theoretical sensitivity curves, largely improved due to a new design of the pendulum arms and of the electronics, are in a very good agreement with the measurements. In particular, a very good sensitivity (10-12 m/Hz1/2) has been obtained in the band 0.1 - 10 Hz). Prototypes of monolithic seismometers are already operational in selected sites around the world both to remotely acquire data for scientific analysis of seismic noise and to collect all the useful information to understand their performances in the very low frequency band. The results of the monolithic sensor as accelerometer (force feed-back configuration) are also presented and discussed.

In this paper we present and discuss the scientific data recorded along one month of data taking of two mechanical monolithic horizontal sensor prototypes located in a blind-ended (side) tunnel 2000 ft deep in the Homestake mine (South Dakota, USA), chosen to host the Deep Underground Science and Engineering Laboratory (DUSEL). The main goal of this test is to provide preliminary data to characterize the Homestake site in the frequency band 10^(-4) ÷ 30Hz and to estimate the level of Newtonian noise, information necessary to understand the feasibility of underground gravitational-wave interferometers sensitive at 1Hz and below. The recorded scientific data and all the technical information obtained with this test are very useful also to understand the performances of the monolithic sensors in the very low frequency band (10^(-6) ÷ 10^(-3) Hz) and to organize an experiment for the low frequency seismic characterization of the Homestake site with monolithic sensors positioned at different levels and orientations.

This paper describes a new mechanical version of the monolithic tunable folded pendulum, developed at the University of Salerno, configurable both as seismometer and, in a force-feedback configuration, as accelerometer. Typical applications of the sensors are in the field of geophysics, including the study of seismic and newtonian noise for characterization of suitable sites for underground interferometers for gravitational waves detection. The sensor, shaped with precision machining and electric-discharge machining, is a very compact instrument, very sensitive in the low-frequency seismic noise band, with a very good immunity to environmental noises. Important characteristics are the tunable resonance frequency and the integrated laser optical readout, consisting of an optical lever and/or an interferometer. The theoretical sensitivity curves, largely improved due to a new design of the pendulum arms and of the electronics, are in a very good agreement with the measurements. The results of the monolithic sensor as accelerometer (force feed-back configuration) are also presented and discussed.

In this paper we describe the scientific data recorded along one month of data taking of two mechanical monolithic horizontal sensor prototypes located in a blind-ended (side) tunnel 2000 ft deep in the Homestake (South Dakota, USA) mine chosen to host the Deep Underground Science and Engineering Laboratory (DUSEL). The two mechanical monolithic sensors, developed at the University of Salerno, are placed, in thermally insulating enclosures, onto concrete slabs connected to the bedrock, and behind a sound-proofing wall. The main goal of this experiment is to characterize the Homestake site in the frequency band 10-4 - 30Hz and to estimate the level of Newtonian noise in a deep underegropund laboratory. The horizontal semidiurnal Earth tide and the Peterson's New Low Noise Model have been measured.

A tunable mechanical horizontal monolithic seismometer/accelerometer, developed for applications in the fields of geophysics and interferometric detection of gravitational waves of second and third generation, is described. The large measurement band (10−3 ÷ 10 Hz) with sensitivities of ≈ 10−12m/, as seismometer, and better than 10−11 m/s2/, as accelerometer, have been obtained with an optimised mechanical design and the introduction of a very sensitive laser interferometric optical readout, the latter aimed also to ensure a very good immunity to environmental noises. Prototypes of seismometers are operational in selected sites both to acquire seismic data for scientific analysis of seismic noise and to collect all the useful information to understand their performances in the very low frequency band (10−6 ÷ 10−3 Hz).

In this paper we describe the scientific data recorded along one month of data taking of two mechanical monolithic horizontal sensor prototypes located in a blind-ended (side) tunnel 2000 ft deep in the Homestake (South Dakota, USA) mine chosen to host the Deep Underground Science and Engineering Laboratory (DUSEL). The two mechanical monolithic sensors, developed at the University of Salerno, are placed, in thermally insulating enclosures, onto concrete slabs connected to the bedrock, and behind a sound-proofing wall. The main goal of this experiment is to characterize the Homestake site in the frequency band 10^(-4) ÷ 30 Hz and to estimate the level of Newtonian noise, providing also the necessary preliminary information to understand the feasibility of underground gravitational-wave interferometers sensitive at 1 Hz and below.

In this paper we describe the scientific data recorded along one month of data taking of two mechanical monolithic horizontal sensor prototypes located in a blind-ended (side) tunnel 2000 ft deep in the Homestake (South Dakota, USA) mine chosen to host the Deep Underground Science and Engineering Laboratory (DUSEL). The two mechanical monolithic sensors, developed at the University of Salerno, are placed, in thermally insulating enclosures, onto concrete slabs connected to the bedrock, and behind a sound-proofing wall. The main goal of this experiment is to characterize the Homestake site in the frequency band 10-4 ÷ 30 H z and to estimate the level of Newtonian noise, providing also the necessary preliminary information to understand the feasibility of underground gravitational-wave interferometers sensitive at 1 H z and below.

In this paper we describe the architecture and the performances of a hybrid modular acquisition and control system prototype for environmental monitoring and geophysics. The system, an alternative to a VME-UDP/IP based system, is based on a dual-channel 18-bit low noise ADC and a 16-bit DAC module at 1 MHz. The module can be configured as stand-alone or mounted on a motherboard as mezzanine. Both the modules and the motherboard can send/receive the configuration and the acquired/correction data for control through a standard EPP parallel port to a standard PC for the real-time computation. The tests have demonstrated that a distributed control systems based on this architecture exhibits a delay time of less than 25 us on a single channel, i.e a sustained sampling frequency of more than 40 kHz (and up to 80 kHz). The system is now under extensive test in the remote controls of seismic sensors (to simulate a geophysics networks of sensors) of a large baseline suspended Michelson interferometer.

In this paper we describe the architecture and the performances of a hybrid modular acquisition and control system prototype developed for the implementation of distributed monitoring and control systems. The system, an alternative to the VME-UDP/IP based system, is based on a dual-channel 18-bit low noise ADC and 16-bit DAC module at 800 kHz, managed by an ALTERA FPGA. Experimental tests have demonstrated that this architecture allows the implementation of distributed control systems with delay time t < 30µs, on single channel, using a standard laptop PC for the real-time computation. The system was used for the longitudinal control of the end mirror of a suspended Michelson Interferometer, performed through an electrostatic actuators, giving effective performances. The preliminary results are also reported.

This paper describes a mechanical monolithic tunable sensor prototype with elliptical hinges, shaped with electric-discharge-machining, that can be used both as seismometer and, in a force-feedback configuration, as accelerometer in the control of mechanical suspensions of interferometric gravitational waves detectors. The monolithic mechanical design and a laser optical readout make it a very compact instrument, very sensitive in the low-frequency seismic noise band and with a very good immunity to environmental noises. The theoretical sensitivity curves and the simulations show a very good agreement with the measurements. Very interesting scientific result its measured natural resonance frequency of ≈ 70mHz with a Q ≈ 140 in air.

In this paper we describe the architecture and the performances of a hybrid modular acquisition and control system prototype for environmental monitoring and geophysics. The system, an improvement of a VME-UDP/IP based system we developed for interferometric detectors of gravitational waves, is based on a dual-channel 18-bit low noise ADC, a 16-bit DAC module at 1MHz, and a 20-bit slower ADC necessary for the acquisition of an external calibration signal. The module can be configured as stand-alone or mounted on a motherboard as mezzanine in parallel with other modules. Both the modules and the motherboard can send/receive the configuration and the acquired/correction data for control through a standard EPP parallel port to a standard PC, where the real-time computation is performed. Experimental tests have demonstrated that the distributed control systems implemented with this architecture exihibit a delay time of less than 25 μs on a single channel, that is a sustained sampling frequency of more than 40kHz. The system is now under extensive test in two different experiments: the remote control and data acquisition of a set of seismometers, velocimeters and accelerometers to simulate a geophysics networks of sensors and the remote control of the end mirrors of a suspended Michelson interferometer through electrostatic actuators for interferometric detectors of gravitational waves.

A 54-year-old female from Brazil with a 2-month history of anterior chest pain episodes was referred to our hospital. Before admission she underwent an ECG stress test that showed significant ST-segment depression in leads V4–V6 together with anginal symptoms. The patient had a family history of sudden cardiac death (2 sisters died at 36 and 54 years of age) and a past history of hypertension. She had never suffered from syncope or palpitations. Biochemical blood parameters and urinalysis were in the normal range. Twelve-lead ECG presented ST-T nonspecific abnormalities (Figure 1) and chest x-ray was normal but showed a mild increase in the second right arch (Figure 2). Figure 1. Standard ECG shows sinus rhythm, normal QRS duration, and nonspecific repolarization changes. Figure 2. Posteroanterior view chest radiography. It shows mild increase in the right second arch. Echocardiogram revealed thickened left ventricular walls, mostly in the lateral and inferior midventricular and distal segments, …