Performance of a large limited streamer tube cell in drift mode

The performance of a large (3x3 $cm^2$) streamer tube cell in drift mode is shown. The detector space resolution has been studied using cosmic muons crossing an high precision silicon telescope. The experimental results are compared with a GARFIELD simulation.Comment: 18 pages, 7 figures. Accepted by Nucl. Instr. and Methods

Monitoring of sea-ice-atmosphere interface in the proximity of arctic tidewater glaciers: The contribution of marine robotics

The Svalbard archipelago, with its partially closed waters influenced by both oceanic conditions and large tidal glaciers, represents a prime target for understanding the effects of ongoing climate change on glaciers, oceans, and ecosystems. An understanding of the role played by tidewater glaciers in marine primary production is still affected by a lack of data from close proximity to glacier fronts, to which, for safety reasons, manned surface vessels cannot get too close. In this context, autonomous marine vehicles can play a key role in collecting high quality data in dangerous interface areas. In particular, the contribution given by light, portable, and modular marine robots is discussed in this paper. The state-of-the-art of technology and of operating procedures is established on the basis of the experience gained in campaigns carried out by Italian National Research Council (CNR) robotic researchers in Ny-Alesund, Svalbard Islands, in 2015, 2017, and 2018 respectively. The aim was to demonstrate the capability of an Unmanned Semi-Submersible Vehicle (USSV): (i) To collect water samples in contact with the front of a tidewater glacier; (ii) to work in cooperation with Unmanned Aerial Vehicles (UAV) for sea surface and air column characterisation in the proximity of the fronts of the glaciers; and (iii) to perform, when equipped with suitable tools and instruments, repetitive sampling of water surface as well as profiling the parameters of the water and air column close to the fronts of the tidewater glaciers. The article also reports the issues encountered in navigating in the middle of bergy bits and growlers as well as the problems faced in using some sensors at high latitudes

Acoustic motion estimation and control for an unmanned underwater vehicle in a structured environment

The problem of identification and navigation, guidance and control in unmanned underwater vehicles (UUVs) is addressed in this paper. A task-function-based guidance system and an acoustic motion estimation module have been integrated with a conventional UUV autopilot within a two-layered hierarchical architecture for closed-loop control. Basic techniques to estimate the robot dynamics using the sensors mounted on the vehicle have been investigated. The proposed identification techniques and navigation, guidance and control (NGC) system have been tested on Roby2, a UUV developed at the Istituto Automazione Navale of the Italian C.N.R. The experimental set-up, as well as the modalities and results, are discussed.Programma Nazionale di Recerche in Antartide (PNRA

Characterisation of Hybrid Pixel Detectors with capacitive charge division

In order to fully exploit the physics potential of the future high energy e+ e- linear collider, a Vertex Tracker providing high resolution track reconstruction is required. Hybrid pixel sensors are an attractive technology due to their fast read-out capabilities and radiation hardness. A novel pixel detector layout with interleaved cells between the readout nodes has been developed to improve the single point resolution. The results of the characterisation of the first processed prototypes are reported.Comment: 5 pages, 2 figures, presented at LCWS2000, Linear Collider Workshop, October 24-28 2000, Fermi National Accelerator Laboratory, Batavia, Illinois, U.S.A. Proceedings to be published by the American Institute of Physic

Atmospheric fluctuations below 0.1 Hz during drift-scan solar diameter measurements

Measurements of the power spectrum of the seeing in the range 0.001-1 Hz have been performed in order to understand the criticity of the transits' method for solar diameter monitoring.Comment: 3 pages, 3 figures, proc. of the Fourth French-Chinese meeting on Solar Physics Understanding Solar Activity: Advances and Challenges, 15 - 18 November, 2011 Nice, Franc

Hybrid Pixel Detector Development for the Linear Collider Vertex Tracker

In order to fully exploit the physics potential of the future high energy e+e- linear collider, a Vertex Tracker able to provide particle track extrapolation with very high resolution is needed. Hybrid Si pixel sensors are an attractive technology due to their fast read-out capabilities and radiation hardness. A novel pixel detector layout with interleaved cells has been developed to improve the single point resolution. Results of the characterisation of the first processed prototypes by electrostatic measurements and charge collection studies are discussed.Comment: 5 pages, 1 figure, to appear in the Proceedings of the 9th Int. Workshop on Vertex Detectors, Lake Michigan MI (USA), September~200

High resolution pixel detectors for e+e- linear colliders

The physics goals at the future e+e- linear collider require high performance vertexing and impact parameter resolution. Two possible technologies for the vertex detector of an experimental apparatus are outlined in the paper: an evolution of the Hybrid Pixel Sensors already used in high energy physics experiments and a new detector concept based on the monolithic CMOS sensors.Comment: 8 pages, to appear on the Proceedings of the International Workshop on Linear Colliders LCWS99, Sitges (Spain), April 28 - May 5, 199

A Pixel Vertex Tracker for the TESLA Detector

In order to fully exploit the physics potential of a e+e- linear collider, such as TESLA, a Vertex Tracker providing high resolution track reconstruction is required. Hybrid Silicon pixel sensors are an attractive sensor technology option due to their read-out speed and radiation hardness, favoured in the high rate TESLA environment, but have been so far limited by the achievable single point space resolution. A novel layout of pixel detectors with interleaved cells to improve their spatial resolution is introduced and the results of the characterisation of a first set of test structures are discussed. In this note, a conceptual design of the TESLA Vertex Tracker, based on hybrid pixel sensors is presentedComment: 20 pages, 11 figure

Silicon photomultiplier readout of a scintillating noble gas detector for homeland security

Detectors based on scintillation by high pressure 4He are a viable technology for instruments against the illicit trafficking of nuclear material. A design based on the use of solid state photodetectors is presented in this paper and the preliminary qualification discussed

Transgenic plants expressing immunosuppressive dsRNA improve entomopathogen efficacy against Spodoptera littoralis larvae

Transgenic plants that express double-stranded RNA (dsRNA) targeting vital insect genes have recently emerged as a valuable new tool for pest control. In this study, tobacco plants were transformed to produce dsRNA targeting Sl 102 gene that is involved in the immune response of Spodoptera littoralis larvae, a serious lepidopteran pest of several crops. Experimental larvae reared on transgenic tobacco lines showed (1) a strongly reduced level of Sl 102 transcripts, which was positively associated with food consumption; (2) a substantial impairment of the encapsulation response mediated by hemocytes; and (3) a marked increase in the susceptibility to Xentari™, a Bacillus thuringiensis-based insecticide. Importantly, this approach may allow a reduction in the doses of B. thuringiensis used for field applications and enhance its killing activity on mature larvae. The results obtained thus support the use of immunosuppressive RNAi plants to enhance the performance of microbial insecticides on lepidopteran larvae