defect detection in additively manufactured components laser ultrasound and laser thermography comparison

Abstract Despite continuous technological advances in additive manufacturing, the lack of non-destructive inspection techniques during the manufacturing process is a limit for the industrial breakthroughs. Additive manufacturing is mainly used in industrial sectors where the zero defect target is crucial. The inclusion of the integrity assessment into the additive manufacturing process would allow corrective actions to be performed before the component is completed. To this end, the development of in-process monitoring and processing techniques is of great interest. This work proposes and compares two remote non-destructive inspection techniques: laser ultrasound and laser thermography. The two techniques are evaluated on Inconel samples with laser drilling holes to establish their sensitivity. Experimental results show that those discontinuities are efficiently detected with both techniques. The remote inspection by optical methods would allow the integration of the evaluation system into the additive manufacturing equipment, thus allowing continuous monitoring throughout the entire production process. Potential benefits and limitations of the two techniques are discussed

THE PHENOMENON OF CYBERCRIME: FROM THE TRANSNATIONAL CONNOTATION TO THE NEED FOR GLOBALIZATION OF JUSTICE

Information technology has brought about epochal changes in every area of society, offering opportunities for development on a social, cultural, and economic level, but also a fertile ground for activities with criminal purposes that take place in cyberspace. The threat present in the intangible world of cyberspace is extremely concrete and is one of the major sources of concern and investment by States, given that the Internet is considered the critical infrastructure for excellence. Cybercrime, characterized by a transnational connotation of borderless or aspatial crime, provides a position of advantage to the cybercriminal compared to the traditional criminal. The development of information technologies has led to the digitization of organized crime which thus succeeds in maximizing profits by exploiting the opportunities offered by new communication technologies and minimizing the risk of being identified, arrested, convicted and of suffering the seizure of the proceeds of criminal activities. Considering the contradictory and inhomogeneous international legal framework due to the transnational scope of cybercrime, the identification of the locus commissi delicti is difficult and the legal prosecution of cybercrimes is complex; therefore, cybercriminals could operate without an adequate response from some states in terms of prevention, sanction, containment and contrast. The sovereignty of States, in the context of cybercrime repression, is identified as an insurmountable obstacle in the creation of a supranational union of law. Therefore, to put legal operators in the real conditions to suppress transnational cybercrime, globalization of justice is needed. Article visualizations

Detection of disbonds in multilayer structures by laser-based ultrasonic technique

Adhesively bonded multi-layer structures are frequently used, mostly in the aerospace industry, for their structural efficiency. Nondestructive evaluation of bond integrity in these types of structures, both after manufacturing and for periodic inspection during service, is extremely important. A laser-based ultrasonic technique has been evaluated for non-contact detection of disbonds in aluminum multi-layer structures. Two configurations have been used to detect disbonded areas: pitch-catch with unidirectional guided wave scan and through-transmission with bidirectional scan. Guided wave scanning was done with a laser line source and air-coupled transducer sensing at 500 kHz, 1 ;MHz, and 2 MHz. Signals showed attenuation of the main frequency component and frequency shift on disbonded areas, whereas, a regular and standard waveform is seen outside disbonds. In through-transmission the longitudinal wave at normal incidence was monitored with a 1 MHz probe. One sample showed, besides the introduced inserts, other disbonded areas. After the ultrasonic measurements the sample was cut to visually check adhesive and interfaces. The guided wave pitch-catch scan allowed fast inspection and quick indication of disbonded zones, while the through-transmission C-Scan provided better definition of defects but was slower and required access from both sides of the test part

Design of a telescopic tower for wind energy production with reduced environmental impact

A prototype of a telescopic pole for wind energy production with low environmental impact and its lifting system for a 60 to 250 kW turbine and a height of 30 m have been designed and manufactured. A telescopic tower, which is raised and lowered by automation or by remote control, allows to differentiate the presence of the generator within the landscape over time. The technology currently available for lifting and lowering wind turbines is made up of telescopic poles of heights of less than 10 meters and with tilting posts of height below 30 m. Without a state of the art to refer to, the telescopic pole and its lifting system have been designed starting from scratch and solving with innovative ideas the various criticalities that have arisen. The design of the telescopic coupling, the design for maintaining the preload and for the rotational decoupling, the optimization the design of the pairs of sleeves by numerical simulations, the design of the pegs and the bushes of the jack-up lifting system have been presented. The prototype was installed in Caltanissetta, Italy, and successfully tested

Mechanochemical Treatment of Soils Contaminated by Heavy Metals in Attritor and Impact Mills: Experiments and Modeling

An integrative approach was developed to support the scale-up from lab-into pilot-scale mechano-chemical reactors for immobilize heavy metals in contaminated mining soil

Elastic characterization of nanometer-thick polymeric film for astrophysics application with an experimental-numerical method

The x-ray detectors on board astrophysics space missions require optical blocking filters that are highly transparent to x-rays. The filter design typically consists of a polymeric film that is a few tens of nanometers thick coated with aluminium. Due to the large size of the filter membrane (from a few tens to a few hundred square centimeters) and the extreme aspect ratio, together with severe loading conditions during launch and different stoichiometries of the polymer that could change its mechanical properties, a characterization study of the employed material is needed. The plane strain bulge test is a well-accepted methodology for the mechanical testing of structures that are less than a micrometer thick, and especially for freestanding membranes. Unfortunately, testing such ultra-thin films is not a simple task due to residual stress and experimental uncertainty at very low pressure. In this work, the elastic properties of an extremely thin (between 45 and 415 nm) membrane made of bare polyimide and coated with aluminium were derived through adopting a combined experimental-numerical methodology based on the bulge test and numerical simulations

Deformation analysis of ATHENA test filters made of plastic thin films supported by a mesh under differential static pressure

Within ESA Cosmic Vision 2015-2025 Science Program, ATHENA was selected to be a Large-class high energy astrophysics space mission. The observatory will be equipped with two interchangeable focal plane detectors named X-Ray Integral Field Unit (X-IFU) and Wide Field Imager (WFI). In order to optimally exploit the detector sensitivity, X-ray transparent filters are required. Such filters need to be extremely thin to maximize the X-ray transparency, that is, no more than a few tens of nm, still they must be able to sustain the severe stresses experienced during launch. Partially representative test filters were made with a thin polypropylene film, coated with Ti, and supported by a thin highly transparent mesh either in stainless steel or niobium. Differential static pressure experiments were carried out on two filter samples. In addition, the roles of the mesh on the mechanical deformation is studied, adopting a finite element model (FEM). The numerical analysis is compared with experimental results and found in good agreement. The FEM is a promising tool that allows to characterize materials and thicknesses in order to optimize the design

The Genetic Origin of Daunians and the Pan-Mediterranean Southern Italian Iron Age Context.

The geographical location and shape of Apulia, a narrow land stretching out in the sea at the South of Italy, made this region a Mediterranean crossroads connecting Western Europe and the Balkans. Such movements culminated at the beginning of the Iron Age with the Iapygian civilization which consisted of three cultures: Peucetians, Messapians, and Daunians. Among them, the Daunians left a peculiar cultural heritage, with one-of-a-kind stelae and pottery, but, despite the extensive archaeological literature, their origin has been lost to time. In order to shed light on this and to provide a genetic picture of Iron Age Southern Italy, we collected and sequenced human remains from three archaeological sites geographically located in Northern Apulia (the area historically inhabited by Daunians) and radiocarbon dated between 1157 and 275 calBCE. We find that Iron Age Apulian samples are still distant from the genetic variability of modern-day Apulians, they show a degree of genetic heterogeneity comparable with the cosmopolitan Republican and Imperial Roman civilization, even though a few kilometers and centuries separate them, and they are well inserted into the Iron Age Pan-Mediterranean genetic landscape. Our study provides for the first time a window on the genetic make-up of pre-Roman Apulia, whose increasing connectivity within the Mediterranean landscape, would have contributed to laying the foundation for modern genetic variability. In this light, the genetic profile of Daunians may be compatible with an at least partial autochthonous origin, with plausible contributions from the Balkan peninsula

X-IFU Filter Wheel Optical Blocking Filters Technology Demonstration Plan

The main purpose of the present plan is to provide a clear path to demonstrate the TRL5 by the Mission Adoption for the three OBFs on the X-IFU Filter Wheel (FW). An effort has been performed in trying to identify what shall be considered technology, for which the maturity has to be demonstrated, and what is design that can still contribute to improve the performances of the FW filters along phases B and C of development. The X-IFU FW filters conceptual design is similar to that defined (during phase A) and described in the "X-IFU Filter Wheel Mechanism and Electronics Design Description", and the "X-IFU Thermal Filters (THFs) Description" documents presented at the I-PRR. The preliminary design of the X-IFU FW Filters rely on heritage from previous missions and characterization tests performed in phase-A on breadboards manufactured by LUXEL Corporation (Friday Harbor, WA, USA). The adoption of a design similar to that of the X-IFU THFs for frame shape and materials, and to that of the WFI FW filters for film and coating thicknesses, as well as for overall dimensions, allow migrating part of the achievements reached by the X-IFU THFs and WFI FW filters to the X-IFU FW filters. For this reason, the TDP for the X-IFU FW filters will be mainly focused on the vibro-acoustic performances. With this respect, minor effort will be dedicated to the thick and very robust meshless filter (25 μm PI + 100 nm Al) designed to observe very bright x-ray sources. The goal of this activity is to demonstrate TRL5 before MAR for the baseline technology of filters manufactured by LUXEL (PI/Al on BeCu mesh). However, in parallel to verify also the maturity of other filter technologies and to mitigate the risks of having only one manufacturer, we will procure and test filter samples and bare meshes of other European manufacturers (OXFORD instruments, XRNanotech). The identified TECHNOLOGY development elements that we consider critical in the X-IFU FW OBFs are described in this document. In section 7 we list the breadboards (BBs) we have identified to perform the necessary characterization tests aimed at demonstrating their maturity

Assessing temporal and geographic contacts across the Adriatic Sea through the analysis of genome-wide data from Southern Italy

AbstractSouthern Italy was characterised by a complex prehistory that started with different Palaeolithic cultures, later followed by the Neolithic transition and the demic dispersal from the Pontic-Caspian Steppe during the Bronze Age. Archaeological and historical evidence points to demic and cultural influences between Southern Italians and the Balkans, starting with the initial Palaeolithic occupation until historical and modern times. To shed light on the dynamics of these contacts, we analysed a genome-wide SNP dataset of more than 700 individuals from the South Mediterranean area (102 from Southern Italy), combined with ancient DNA from neighbouring areas. Our findings revealed high affinities of South-Eastern Italians with modern Eastern Peloponnesians, and a closer affinity of ancient Greek genomes with those from specific regions of South Italy than modern Greek genomes. The higher similarity could be associated with the presence of a Bronze Age component ultimately originating from the Caucasus and characterised by high frequencies of Iranian and Anatolian Neolithic ancestries. Furthermore, to reveal possible signals of natural selection, we looked for extremely differentiated allele frequencies among Northern and Southern Italy, uncovering putatively adapted SNPs in genes involved in alcohol metabolism, nevi features and immunological traits, such as ALDH2, NID1 and CBLB