Analisi della distribuzione di temperatura dell'aria in prossimità di un banco frigo verticale di un supermercato

Questo studio è suddiviso in tre parti: la prima affronta il tema dell'audit energetico negli edifici ad uso commerciale, la seconda introduce il problema della stratificazione termica dell'aria in un locale, concentrando l'attenzione sul modello fisico e studiando i modelli numerici che meglio possano simulare i campi termici e dinamici del caso in studio. La terza parte,più di pertinenza ingegneristica, affronta l'analisi termica delle zone contigue ad un banco frigo in un supermercato e approfondisce lo studio sulla parametrizzazione della velocità della lama d'aria

Ductile cast irons: microstructure influence on fatigue crack propagation resistance

Microstructure influence on fatigue crack propagation resistance in five different ductile cast irons(DCI) was investigated. Four ferrite/pearlite volume fractions were considered, performing fatigue crackpropagation tests according to ASTM E647 standard (R equals to 0.1, 0.5 and 0.75, respectively). Results werecompared with an austempered DCI. Damaging micromechanisms were investigated according to the followingprocedures:- “traditional” Scanning Electron Microscope (SEM) fracture surfaces analysis;- SEM fracture surface analysis with 3D quantitative analysis;- SEM longitudinal crack profile analysis- Light Optical Microscope (LOM) transversal crack profile analysis

Stiffened panels damage tolerance determination using an optimization procedure based on a linear delamination growth approach

The damage tolerance of delaminated composite panels under compressive load is usually numerically evaluated by means of computationally expensive non-linear approaches. In this study, an alternative numerical linear approach, able to mimic the delamination propagation initiation, is proposed. With the aim to exploit its benefits, in terms of computational costs reduction, the proposed linear methodology has been used in this study in conjunction with an optimization analysis to assess the damage tolerance of stiffened composite panels with an impact induced delamination under compression. Indeed, the optimization was aimed to find the minimum delamination growth initiation load for a delaminated stiffened panel with variable delamination size and position, providing indications on the damage tolerance capability of the stiffened panel with an arbitrary positioned and sized delamination induced (as an example) by a low energy impact

WEUSEDTO—Water End USE Dataset and TOols: An open water end use consumption dataset and data analytics tools

Globalization, climate changes, innovative technologies and new human habits have increased atten- tion to water conservation and management. Therefore, behavioural studies became a key element to understand how and when water is used in residential environment. Water End USE Dataset and TOols (WEUSEDTO), an open water end use consumption dataset and data analytics tools, has been released to help researchers, water utilities and companies to test models and algorithms on real water consumption data. The dataset combines with some notebook python able to analyse high-resolution water data (data recorded with 1 sample per second) to provide several tools to manage raw data, compute statistical analysis, learn fixture usage and generate synthetic simulation models. In addition, washbasin flow data were used as a test case to illustrate the main features of WEUSEDTO: providing volume and duration of single events, classifying usages and simulating user’s behaviour

Laboratory and on-site tests for rapid runway repair

The attention to rapid pavement repair has grown fast in recent decades: this topic is strategic for the airport management process for civil purposes and peacekeeping missions. This work presents the results of laboratory and on-site tests for rapid runway repair, in order to analyse and compare technical and mechanical performances of 12 different materials currently used in airport. The study focuses on site repairs, a technique adopted most frequently than repairs with modular elements. After describing mechanical and physical properties of the examined materials (2 bituminous emulsions, 5 cement mortars, 4 cold bituminous mixtures and 1 expanding resin), the study presents the results of carried out mechanical tests. The results demonstrate that the best performing material is a one-component fast setting and hardening cement mortar with graded aggregates. This material allows the runway reopening 6 h after the work. A cold bituminous mixture (bicomponent premixed cold asphalt with water as catalyst) and the ordinary cement concrete allow the reopening to traffic after 18 h, but both ensure a lower service life (1000 coverages) than the cement mortar (10,000 coverages). The obtained results include important information both laboratory level and field, and they could be used by airport management bodies and road agencies when scheduling and evaluating pavement repairs

Damaging micromechanisms characterization in a ferritic-pearlitic ductile cast iron

The analysis of the damaging micromechanisms in Ductile Cast Irons is often focused on ferritic matrix. Up to ten years ago, for this grades of DCIs, the main damaging micromechanism was identified with the graphite elements - ferritic matrix debonding. More recent experimental results showed the presence of an internal gradient of mechanical properties in the graphite elements and the importance of other damaging micromechanisms, with a negligible importance of the graphite elements - ferritic matrix debonding mechanism. In this work, damaging micromechanisms development in a ferritic - pearlitic DCI have been investigated by means of tensile tests performed on mini-tensile specimens and observing the specimens lateral surfaces by means of a scanning electro microscope (SEM) during the tests ("in-situ" tests). Experimental results have been compared with the damaging micromechanisms observed in fully ferritic and fully pearlitic DCIs

Use of Forest Residues for Building Forest Biomass Supply Chains: Technical and Economic Analysis of the Production Process

(c) there are strong margins for economic profits at the level of each single supply basi

Parachute emergency landing simulation and enhanced composite material characterization for General Aviation aircraft

General Aviation (GA) aircraft crashworthiness of the vehicle when it hits the ground after the parachute deployment is an important issue. The current dynamic emergency landing regulation (CS 23.562) defines the maximum human tolerant accelerations under both vertical and horizontal directions. This article aims to compare two different aircraft configurations: metal low-wing and composite high-wing ones. Both are two-seats and single-engine GA aircraft. The purpose of the analysis is to check whether the seats and restraint systems met human injury tolerance standards and to determine the possible impact on passengers in the cabin space due to shock loads. Finite element analysis of the fuselage sections for both configurations is performed using the commercial LS-Dyna solver. An extensive campaign of experimental tests has been performed on the composite samples for tuning and validating the model and to find the transition from an undamaged up to totally collapsed sample. The material of the composite fuselage has been characterized through experimental tests. The adopted material model has been refined to match with the performed experimental analysis, allowing high-fidelity modeling. A parametric analysis has been performed to determine the optimal impact angle in terms of lumbar injuries and loads transmitted by the seat belt due to aircraft contact with the ground, thereby increasing the level of safety. The investigations carried out may be an important indicator of the design of the parachute system