Scintillating double beta decay bolometers

We present the results obtained in the development of scintillating Double Beta Decay bolometers. Several Mo and Cd based crystals were tested with the bolometric technique. The scintillation light was measured through a second independent bolometer. A 140 g CdWO_4 crystal was run in a 417 h live time measurement. Thanks to the scintillation light, the alpha background is easily discriminated resulting in zero counts above the 2615 keV gamma line of Thallium 208. These results, combined with an extremely easy light detector operation, represent the first tangible proof demonstrating the feasibility of this kind of technique.Comment: 15 pages, 8 figure

Effect of in-source beam shaping and laser beam oscillation on the electromechanical properties of Ni-plated steel joints for e-vehicle battery manufacturing

Laser welding is a key enabling technology that transitions toward electric mobility, producing joints with elevated electrical and mechanical properties. In the production of battery packs, cells to busbar connections are challenging due to strict tolerances and zero-fault policy. Hence, it is of great interest to investigate how beam shaping techniques may be exploited to enhance the electromechanical properties as well as to improve material processability. Industrial laser systems often provide the possibility to oscillate dynamically the beam or redistribute the power in multicore fibers. Although contemporary equipment enables elevated flexibility in terms of power redistribution, further studies are required to indicate the most adequate solution for the production of high performance batteries. Within the present investigation, both in-source beam shaping and beam oscillation techniques have been exploited to perform 0.2-0.2 mm Ni-plated steel welds in lap joint configuration, representative of typical cell to busbar connections. An experimental campaign allowed us to define process feasibility conditions where partial penetration welds could be achieved by means of in-source beam shaping. Hence, beam oscillation was explored to perform the connections. In the subset of feasible conditions, the mechanical strength was determined via tensile tests alongside electrical resistance measurements. Linear welds with a Gaussian beam profile enabled joints with the highest productivity at constant electromechanical properties. Spatter formation due to keyhole instabilities could be avoided by redistributing the emission power via multicore fibers, while dynamic oscillation did not provide significant benefits

Characterisation of the Thermal Damage in a Martensitic Steel Substrate Consequent to Laser Cladding Process

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Digital Recording of Historical Defensive Structures in Mountainous Areas Using Drones: Considerations and Comparisons

Digital recording of historic buildings and sites in mountainous areas could be challenging. The paper considers and discusses the case of historical defensive structures in the Italian Alps, designed and built to be not accessible. Drone images and photogrammetric techniques for 3D modeling play a fundamental role in the digital documentation of fortified constructions with non-contact techniques. This manuscript describes the use of drones for reconstructing the external surfaces of some fortified structures using traditional photogrammetric/SfM solutions and novel methods based on NeRFs. The case of direct orientation based on PPK and traditional GCPs placed on the ground is also discussed, considering the difficulties in placing and measuring control points in such environments

Hand-Held Laser Welding of AISI301LN for components with aesthetic requirements: Toward the integration of machine and human intelligence

The use of Hand-Held Laser Welding (HHLW) systems in the industry has been rapidly growing in recent years as an alternative solution to conventional manual arc-based welding systems. The decreasing cost of fiber laser sources and optics has been a driving factor in enabling a wider use of HHLW systems, beyond the established advantages of laser technology with respect to arc-based systems. While the industrial use of HHLW increases, the subject matter has been studied sparingly in the scientific literature. Due to the intrinsic flexibility of the technology, HHLW systems are highly appealing for joining relatively low thickness metals (≤2 mm) in autogenous configuration in sectors where production lots present low batch and high variability. However, a critical aspect of HHLW is correlated to the operator skill, where welding velocities can vary within and between the welds affecting both their aesthetic and mechanical properties. Hence, the development of combined digital and physical approaches to support manual operations may be highly beneficial. The current study presents an open laboratory HHLW system designed for process development purposes. Beyond conventional manual welding operations, the welding torch could be arranged in different configurations. The system could be combined with a linear axis (enabling welding with stable velocity and inclination) or manually with the aid of a newly developed roller device designed to provide constant speed and inclination. First, the process was benchmarked by joining in butt weld configuration 2 mm thick AISI301LN stainless steel sheets with the linear axis. Successively, four operators with different levels of training (rookie and professional) realized welds with the system in hand-held configuration and with the mechanical roller. The weld width variability was assessed as a direct indicator for aesthetic compliance while tensile tests were allowed to determine the mechanical properties of the joint obtained with different configurations

Zystoskopie bei einem Rind mit Urachus persistens-Ruptur

Die Arbeit beschreibt die klinischen, sonographischen und zystoskopischen Befunde sowie die Therapie bei einem 2-jährigen, 7 Monate trächtigen Braunviehrind mit Ruptur des Urachus persistens. Das Leitsymptom war ein birnförmiges Abdomen bei stark gestörtem Allgemeinbefinden. Die Blutuntersuchung ergab eine hochgradige Azotämie. Bei der Ultraschalluntersuchung wurde ein Aszites festgestellt, welcher aufgrund der massiv erhöhten Kreatininkonzentration im Punktat als Uroperitoneum klassiert wurde. Bei der Zystoskopie konnte das Endoskop über die Harnblase in einen persistierenden Urachus eingeführt werden. Aufgrund sämtlicher Befunde wurde die Diagnose Uroperitoneum infolge Ruptur eines Urachus persistens gestellt. Als Therapie wurde eine Laparotomie in der linken Flanke mit doppelter Ligation des Urachus durchgeführt. Innerhalb von wenigen Tagen normalisierte sich der Zustand des Rindes. Es hat inzwischen normal gekalbt und erfreut sich bester Gesundheit This case report describes the clinical, ultrasonographic and cystoscopic findings and treatment in a two-year-old Swiss Braunvieh heifer with rupture of a patent urachus. The lead signs in the seven-month-pregnant heifer were markedly abnormal general condition and demeanour and a pear-shaped abdomen. The heifer had severe azotaemia, and abdominal ultrasonography revealed ascites, which was diagnosed as uroperitoneum based on an elevated creatinine level in the fluid. A patent urachus was identified during cystoscopy; the endoscope could be advanced beyond the apex of the urinary bladder into the urachus. Based on all the findings, a diagnosis of uroperitoneum attributable to rupture of a patent urachus was made. The urachus was ligated twice via a left-flank laparotomy. The general condition normalised within a few days of surgery, and the patient calved normally and was in good health at follow-up evaluation

Impact of 40 years poplar cultivation on soil carbon stocks and greenhouse gas fluxes

International audienceWithin the JRC Kyoto Experiment in the Regional Park and UN-Biosphere Reserve "Parco Ticino" (North-Italy, near Pavia), the soil carbon stocks and fluxes of CO2, N2O, and CH4 were measured in a poplar plantation in comparison with a natural mesohygrophilous deciduous forest nearby, which represents the pristine land cover of the area. Soil fluxes were measured using the static and dynamic closed chamber techniques for CH4 N2O, and CO2, respectively. We made further a pedological study to relate the spatial variability found with soil parameters. Annual emission fluxes of N2O and CO2 and deposition fluxes of CH4 were calculated for the year 2003 for the poplar plantation and compared to those measured at the natural forest site. N2O emissions at the poplar plantation were 0.15$plusmn;0.1 g N2O m-2 y-1 and the difference to the emissions at the natural forest of 0.07±0.06 g N2O m-2 y-1 are partly due to a period of high emissions after the flooding of the site at the end of 2002. CH4 consumption at the natural forest was twice as large as at the poplar plantation. In comparison to the relict forest, carbon stocks in the soil under the poplar plantation were depleted by 61% of surface (10 cm) carbon and by 25% down the profile under tillage (45 cm). Soil respiration rates were not significant different at both sites with 1608±1053 and 2200±791 g CO2 m-2 y-1 at the poplar plantation and natural forest, respectively, indicating that soil organic carbon is much more stable in the natural forest. In terms of the greenhouse gas budget, the non-CO2 gases contributed minor to the overall soil balance with only 0.9% (N2O) and -0.3% (CH4 of CO2-eq emissions in the natural forest, and 2.7% (N2O) and -0.2% of CO2-eq. emissions in the poplar plantation. The very high spatial variability of soil fluxes within the two sites was related to the morphology of the floodplain area, which was formed by the historic course of the Ticino river and led to a small-scale (tenth of meters) variability in soil texture and to small-scale differences in elevation. Differences of site conditions are reflected by differences of inundation patterns, ecosystem productivity, CO2 and N2O emission rates, and soil contents of carbon and nitrogen. Additional variability was observed during a flooding event and after fertilisation at the poplar site. Despite of this variability, the two sites are comparable as both originate from alluvial deposits. The study shows that changes in soil carbon stocks and related fertility are the most visible phenomena after 40 years of land use change from a pristine forest to a fast growing poplar plantation. Therefore, the conservation and careful management of existing carbon stocks deserves highest priority in the context of the Kyoto Protocol

Electrochemistry of cyclic triimidazoles and their halo derivatives: A casebook for multiple equivalent centers and electrocatalysis

A family of cyclic triazines, based on the triimidazo[1,2-a:1\u2032,2\u2032-c:1\u2033,2\u2033-e][1,3,5]triazine scaffold, has recently caught attention due to its variegated solid state photoluminescent properties (e.g., crystallization induced emission, fluomechanochromism, dual fluorescence, room temperature ultralong phosphorescence), tuned by proper functionalization of the cyclic core. From an electrochemical point of view, this family of heteroaromatic cyclic triazines is unexplored. A cyclic voltammetry study is here performed aiming to clarify structure/electroactivity relationship. The peculiar molecular structure of this class of molecules offers a multi-approach case study, spanning from multiple equivalent redox site interactions in small hoops (due to ideally C3h symmetry) to carbon-halogen bond reactivity in the presence of catalytic metal electrode surfaces (for \u2013Br and \u2013I derivatives). Results point to a poor heteroannular aromaticity along the rigid, planar cyclotrimer, with each equivalent redox site acting quite independently. An unusually higher electrocatalytic performance of gold with respect to silver electrode for the electrocleavage of carbon-halogen bonds (that decreases by increasing number of halo substituents) is tentatively explained in term of a specific interaction between gold and the nitrogen-rich planar cyclotrimer platform