Bioremediation of large concentration of organic compounds in lagoon groundwater

Old landfill, Venice logoon, microbiological tests, chemical laboratory tests, anaerobic barrier’s wells

On the Preliminary Structural Design Strategy of the Wing of the Next-Generation Civil Tiltrotor Technology Demonstrator

The T-WING project is a Clean Sky 2 research project aimed at designing, manufacturing, qualifying and flight-testing the new wing of the Next-Generation Civil Tiltrotor Technology Demonstrator (NGCTR-TD), as part of the Fast Rotorcraft Innovative Aircraft Demonstrator Platforms (FRC IADP) activities. Requirements, design strategy, methodology and main steps followed to achieve the composite wing preliminary design are presented. The main driving requirements have been expressed in terms of dynamic requirements (e.g., limitations on natural frequencies), aeroelastic requirements, i.e., compliance with European Aviation Safety Agency (EASA) CS-25 and CS-29 Airworthiness Requirements), structural requirements (e.g., target wing structural mass), functional requirements (e.g., fuel tanks, accessibility, assembly and integration, etc.) and wing preliminary loads. Based on the above-mentioned requirements, the first design loop is performed by targeting an optimal wing structure able to withstand preliminary design loads, and simultaneously with stiffness and inertia distributions leading to a configuration free from flutter within the flight envelope. The outcome from the first design loop is then used to refine the model and compute more reliable flight loads and repeat aeroelastic analysis, returning further requirements to be fulfilled in terms of wing stiffness and inertia distributions. The process is iterated till the fulfillment of all the project requirements

Wing structure of the next-generation civil tiltrotor: From concept to preliminary design

The main objective of this paper is to describe a methodology to be applied in the preliminary design of a tiltrotor wing based on previously developed conceptual design methods. The reference vehicle is the Next-Generation Civil Tiltrotor Technology Demonstrator (NGCTR-TD) developed by Leonardo Helicopters within the Clean Sky research program framework. In a previous work by the authors, based on the specific requirements (i.e., dynamics, strength, buckling, functional), the first iteration of design was aimed at finding a wing structure with a minimized structural weight but at the same time strong and stiff enough to comply with sizing loads and aeroelastic stability in the flight envelope. Now, the outcome from the first design loop is used to build a global Finite Element Model (FEM), to be used for a multi-objective optimization performed by using a commercial software environment. In other words, the design strategy, aimed at finding a first optimal solution in terms of the thickness of composite components, is based on a two-level optimization. The first-level optimization is performed with engineering models (non-FEA-based), and the second-level optimization, discussed in this paper, within an FEA environment. The latter is shown to provide satisfactory results in terms of overall wing weight, and a zonal optimization of the composite parts, which is the starting point of an engineered model and a detailed FEM (beyond the scope of the present work), which will also take into account manufacturing, assembly, installation, accessibility and maintenance constraints

ANALISI STRATEGICA E VALUTAZIONE D'AZIENDA

La stima del valore del capitale delle imprese nn è un calcolo matematico, ma l'esito di un giudizio ragionato e motivato. Per questo motivo è così importante la cosiddetta "analisi fondamentale" e, in particolare, nel suo ambito l'analisi strategica attraverso cui il valutatore può ricostruire le principali assumption che alimentano i modelli valutativi ed esprimere un giudizio sulla loro ragionevolezza

Active Control for Buffet Load Alleviation on the Fin of a High Performance Training Aircraft

This paper describes the activities performed by Politecnico di Milano in collaboration with LEONARDO COMPANY S.P.A.-Aircraft Division focused on the design of an active control aiming at alleviating the buffet loads acting on the fin of a high performance training aircraft. A public finite element model, called AFA, representing a lightweight fighter has been adopted for this investigation. Starting from already available wind tunnel pressure measurements on a geometrically similar model, a buffet load model has been identified. Using this model as disturbance input, a dedicated control system has been developed and validated through numerical simulations. Both design and off-design flight conditions have been considered, inside a specific ight envelope defined including flight conditions most subjected to buffet effects

The Effect of C60 and Pentacene Adsorbates on the Electrical Properties of CVD Graphene on SiO2 (Dataset)

Dataset of the GFETs measurements related to the publication: "The Effect of C60 and Pentacene Adsorbates on the Electrical Properties of CVD Graphene on SiO2", MDPI, Nanomaterials, 2023. The dataset includes: AFM raw data Raman spectroscopy raw data GFETs IV and gate sweep raw dat

TWING: Preliminary Vibration Test Activities

A vibration test is the most used method for performing the modal analysis of a structure. The purpose of the vibration test is to determine dynamic characteristics such as the natural frequencies, mode shapes and structural damping coefficients of the most important vibration modes inherent to the dynamic response of a test or flight article referring to its global stiffness and mass distribution. A Ground Vibration Test (GVT) has a unique combination of the importance of structural dynamics in aircraft and safety requirements. A vibration test on a large structure always involves multiple inputs and multiple outputs (MIMO) frequency response testing. This paper summarizes the main activities performed and those planned for the next future in the framework of the T-WING CleanSky2 project. It aims to develop a composite tiltrotor wing to be used as a flying demonstrator. Several numerical models have been prepared, from a simple beam-like reference to a very detailed one. Parallelly, laboratory activities have been carried out, and as soon as a partial full-scale mockup has been available, preliminary test activities have been completed. Together with these activities a setup has been prepared for the experimental measurement of the inertia characteristics of the movable surfaces to be installed on the real wing. Scaled tests have been performed to check the approach validity

Wing Structure of the Next-Generation Civil Tiltrotor: From Concept to Preliminary Design

The main objective of this paper is to describe a methodology to be applied in the preliminary design of a tiltrotor wing based on previously developed conceptual design methods. The reference vehicle is the Next-Generation Civil Tiltrotor Technology Demonstrator (NGCTR-TD) developed by Leonardo Helicopters within the Clean Sky research program framework. In a previous work by the authors, based on the specific requirements (i.e., dynamics, strength, buckling, functional), the first iteration of design was aimed at finding a wing structure with a minimized structural weight but at the same time strong and stiff enough to comply with sizing loads and aeroelastic stability in the flight envelope. Now, the outcome from the first design loop is used to build a global Finite Element Model (FEM), to be used for a multi-objective optimization performed by using a commercial software environment. In other words, the design strategy, aimed at finding a first optimal solution in terms of the thickness of composite components, is based on a two-level optimization. The first-level optimization is performed with engineering models (non-FEA-based), and the second-level optimization, discussed in this paper, within an FEA environment. The latter is shown to provide satisfactory results in terms of overall wing weight, and a zonal optimization of the composite parts, which is the starting point of an engineered model and a detailed FEM (beyond the scope of the present work), which will also take into account manufacturing, assembly, installation, accessibility and maintenance constraints

The Effect of Removable Orthodontic Appliances on Oral Microbiota: A Systematic Review

Background (1): Removable orthodontic appliances may favor plaque accumulation and oral microbe colonization. This might be associated with intraoral adverse effects on enamel or periodontal tissues. The proposed systematic review was carried out to evaluate qualitatively and quantitatively the microbiological changes occurring during orthodontic therapy with removable orthodontic appliances. Methods (2): PubMed, Cochrane Library, Embase, Web of Science, Scopus, Ovid Medline, and Dentistry and Oral Sciences Source were searched. The research included every article published up to January 2020. The Preferred Reporting Items for Reporting Systematic reviews and Meta Analyses (PRISMA) protocol and the “Swedish Council on Technology Assessment in Health Care Criteria for Grading Assessed Studies” (SBU) method were adopted to conduct this systematic review. Results (3): The current study has a moderate evidence, demonstrating that removable appliances do influence the oral microbiota. Significant alterations occur just 15 days after the beginning of therapy, independently from the type of appliance. Furthermore, the levels of oral pathogens decrease significantly or even returned to pre-treatment levels several months later the therapy end. Conclusions (4): This review suggests that orthodontic treatment with removable appliances induces changes to oral microflora, but these alterations might not be permanent