Aerogel technology for thermal insulation of cryogenic tanks. Numerical analysis for comparison with traditional insulating materials

The traditional choice of insulation material for liquefied natural gas (LNG) transportation with cryogenic tankers is the back-filled perlite-based system. However, aiming to further cut down the insulation cost, spare additional arrangement space, and provide safety in installation and maintenance, the requirement of looking for alternative materials still exists. Fiber-reinforced aerogel blankets (FRABs) could represent good candidates in designing insulation layers for LNG cryogenic storage because of their ability to ensure adequate thermal performance without the need to create deep vacuum conditions in the annular space of the tank. In this work, a finite element method (FEM) model was developed to study the thermal insulation performance of a commercial FRAB (Cryogel ® Z) for application in cryogenic storage/transport LNG tanks, comparing it with the performance of traditional perlite-based systems. Within the reliability limits of the computational model, the analysis proved that FRAB insulation technology gave encouraging results and might be potentially scalable for transporting cryogenic liquid. In addition to demonstrating superior performance in terms of thermal insulating efficiency and boil-off rate over the perlite-based system, as far as a perspective of cost savings and space gain, FRAB technology allows for higher levels of insulation without vacuum and with lower thickness of the outer shell, which is therefore beneficial for storing more material and lightening the weight of the LNG transportation semitrailer

Detachment of Plasters in Masonry Buildings: Analysis by Acoustic Emission and Numerical Simulation

An innovative laboratory procedure is described for testing the mechanical adhesion of new dehumidified mortars applied in the restoration works. A specific adherence test was carried out on composite specimens made by stone block and repair mortar. During the laboratory test the acoustic emission (AE) technique was employed, in order to estimate the amount of energy released from fracture propagation in the adherence surface between mortar and stone. A numerical simulation follows the experimental data. The evolution of detachment process of mortar in a coupled stone brick–mortar system was analysed by AE signals, which can improve the numerical model and predict the failure mode in the adhesion surface of repair plaster

Direct vs 2-stage approaches to structured motif finding

BACKGROUND: The notion of DNA motif is a mathematical abstraction used to model regions of the DNA (known as Transcription Factor Binding Sites, or TFBSs) that are bound by a given Transcription Factor to regulate gene expression or repression. In turn, DNA structured motifs are a mathematical counterpart that models sets of TFBSs that work in concert in the gene regulations processes of higher eukaryotic organisms. Typically, a structured motif is composed of an ordered set of isolated (or simple) motifs, separated by a variable, but somewhat constrained number of “irrelevant” base-pairs. Discovering structured motifs in a set of DNA sequences is a computationally hard problem that has been addressed by a number of authors using either a direct approach, or via the preliminary identification and successive combination of simple motifs. RESULTS: We describe a computational tool, named SISMA, for the de-novo discovery of structured motifs in a set of DNA sequences. SISMA is an exact, enumerative algorithm, meaning that it finds all the motifs conforming to the specifications. It does so in two stages: first it discovers all the possible component simple motifs, then combines them in a way that respects the given constraints. We developed SISMA mainly with the aim of understanding the potential benefits of such a 2-stage approach w.r.t. direct methods. In fact, no 2-stage software was available for the general problem of structured motif discovery, but only a few tools that solved restricted versions of the problem. We evaluated SISMA against other published tools on a comprehensive benchmark made of both synthetic and real biological datasets. In a significant number of cases, SISMA outperformed the competitors, exhibiting a good performance also in most of the cases in which it was inferior. CONCLUSIONS: A reflection on the results obtained lead us to conclude that a 2-stage approach can be implemented with many advantages over direct approaches. Some of these have to do with greater modularity, ease of parallelization, and the possibility to perform adaptive searches of structured motifs. As another consideration, we noted that most hard instances for SISMA were easy to detect in advance. In these cases one may initially opt for a direct method; or, as a viable alternative in most laboratories, one could run both direct and 2-stage tools in parallel, halting the computations when the first halts

Optimization of Curvilinear Stiffener Beam Structures Simulated by Beam Finite Elements with Coupled Bending–Torsion Formulation

This research presents the application of a beam finite element, specifically derived for simulating bending–torsion coupling in equivalent box-beam structures with curvilinear stiffeners. The stiffener path was simulated and optimized to obtain an expected coupling effect with respect to four typical static load cases, including geometric constraints related to the additive manufacturing production method. The selected load condition was applied to the centroid of the beam section, and the structure performance was consequently determined. A variation in load position up to onefourth of the beam width was considered for investigating the stiffener path variation corresponding to a minimum bending–torsion coupling effect. The results demonstrated the capability of such a beam finite element to correctly represent the static behavior of beam structures with curvilinear stiffeners and show the possibility to uncouple its bending–torsion behavior using a specific stiffener orientation. The simulation of a laser powder bed fusion process showed new opportunities for the application of this technology to stiffened panel manufacturing

Static and thermal FE analysis of a Flexible Electronic BOard (FEBO) prototype and the characterization of its innovative materials

An FE model of an experimental flexible electronic board was built to determine its performance in terms of mechanical and thermal distortions, heat and transient thermal flow, thereby detecting critical issues and identifying opportunities for improvement. Commercial sensors were connected to the flexible board (100x40x2mm), which was based on a commercial thermoplastic polyurethane (TPU), with a PEDOT-based conductive resin trapped in a PEGDA network, a biocompatible polymer. Three thermal loads (ΔT=175°C, ΔT=100°C, ΔT=50°C) were applied which revealed critical stresses for high ΔTs but at ΔT=50°C only the connectors had a critical σvm, while for ΔT=50°C + 1mm displacement a critical strain value occurred in one area of the substrate. Heat transient analysis and overheating simulations were performed to determine the heat flow behavior for the photodiode and accelerometer. FE analyses allow more studies to be undertaken to improve material properties and suggest redesign activities for similar concept demonstrators. The funds of the European Union and the Piedmont Region, and agreements with the most important players in SBE (Simulation Based Engineering) software sales and services, allowed the authors (ITACAe srl, Proplast, and Politecnico di Torino) to conduct industrial research and experimental development together with manufacturers and users of innovative technologies to identify, study and optimize the design parameters of the board while simultaneously contributing to its technological development

Futures of Work: Perspectives from the Maker Movement

The work presented in this report attempts to explore other realms about the future(s) of work beyond the strongly driven narrative of digital transformation. We have addressed one particular grassroots community, the Maker Movement, which is de facto enabling new models of education, collaborative work, and manufacture. Movements like the Maker Movement can be inspirational of policy making in areas of great complexity and uncertainties as work, employment, jobs are. We suggest that debates about futures of work need to mobilise the imagination, insights and expectations of wide ranges of society. Policy making should be nurturing necessary studies, experiments and conversations until some resilient ideas are found.JRC.I.2-Foresight, Behavioural Insights and Design for Polic

Monitoring Approach to Evaluate the Performances of a New Deposition Nozzle Solution for DED Systems

In order to improve the process efficiency of a direct energy deposition (DED) system, closed loop control systems can be considered for monitoring the deposition and melting processes and adjusting the process parameters in real-time. In this paper, the monitoring of a new deposition nozzle solution for DED systems is approached through a simulation-experimental comparison. The shape of the powder flow at the exit of the nozzle outlet and the spread of the powder particles on the deposition plane are analyzed through 2D images of the powder flow obtained by monitoring the powder depositions with a high-speed camera. These experimental results are then compared with data obtained through a Computational Fluid Dynamics model. Preliminary tests are carried out by varying powder, carrier, and shielding mass flow, demonstrating that the last parameter has a significant influence on the powder distribution and powder flow geometry

CEUS Retrograde Cystography Is Helpful in Percutaneous Drainage of Complex Posttransplant Lymphocele

After monolateral dual kidney transplantation, a 69 years old male patient developed symptomatic lymphocele with mild hydroureteronephrosis, impaired renal function, and right inferior limb oedema. A percutaneous ultrasound-guided drainage of the fluid collection was planned, but the complex mutual relations between the collection and the renal hilus did not allow to identify a suitable route for a safe drainage insertion during conventional ultrasound examination. A retrograde cystography using echographic contrast agent was, therefore, performed, and it clarified the position of both ureters and the renal vessels, permitting an harmless ultrasound-guided percutaneous lymphocele drainage. In conclusion contrast-enhanced ultrasound retrograde cystography may be helpful in percutaneous drainage of complex posttransplant lymphocele

A deep learning based object identification system for forest fire detection

POCI-01-0247-FEDER-038342Forest fires are still a large concern in several countries due to the social, environmental and economic damages caused. This paper aims to show the design and validation of a proposed system for the classification of smoke columns with object detection and a deep learning-based approach. This approach is able to detect smoke columns visible below or above the horizon. During the dataset labelling, the smoke object was divided into three different classes, depending on its distance to the horizon, a cloud object was also added, along with images without annotations. A comparison between the use of RetinaNet and Faster R-CNN was also performed. Using an independent test set, an F1-score around 80%, a G-mean around 80% and a detection rate around 90% were achieved by the two best models: both were trained with the dataset labelled with three different smoke classes and with augmentation; Faster R-CNNN was the model architecture, re-trained during the same iterations but following different learning rate schedules. Finally, these models were tested in 24 smoke sequences of the public HPWREN dataset, with 6.3 min as the average time elapsed from the start of the fire compared to the first detection of a smoke column.publishersversionpublishe

Understanding of the Nutri-Score front-of-pack label by Italian Medical Professionals and its effect on food choices: a web-based study on knowledge, attitudes and practices

A growing number of European Countries have adopted front-of-pack nutrition labels (FPNL) in order to assist costumers' alimentary choices, and particularly Nutri-Score. While its acceptance in Italy has been slowed by ongoing debates, we assessed corresponding knowledge, attitudes and practices of a sample of Italian Medical Professionals (MP)