Search results for "Tempera"
showing 10 items of 4201 documents
A methodology for evaluating the flexibility potential of domestic air-conditioning systems
2020
The paper presents a methodology for quantifying the electrical flexibility potential of air-conditioning systems (ACS) installed in residential buildings according to the building envelope characteristics and the ACS performance. In order to provide a thorough analysis of the issue, the ACS baseline consumption referred to the indoor temperature of 24°C has been computed for three typical residential buildings built in the South of Italy over different periods. The baseline consumption was used as a reference to estimate the effect of the set point temperature change on the ACS power profile. The results showed that increasing the set-point temperature of ACS by 2°C and 4°C leads to a redu…
Heat in Metal Cutting
2008
This chapter provides comprehensive knowledge regarding thermal effects during the cutting process with both uncoated and coated cutting tools. Main heat sources and flowing heat fluxes into the tool, chip and workpiece are characterized and quantified. The heat distribution models that allow the analytical prediction of heat partition between the tool and the chip are specified. They consider such thermal properties as specific heat, thermal conductivity and diffusivity, Peclet thermal number, and heat transmission ratio, all as functions of temperature. Finite element method and finite difference method simulations applied to the prediction of temperature fields are outlined for turning a…
Process mechanics in Friction Stir Extrusion of magnesium alloys chips through experiments and numerical simulation
2017
Abstract Friction Stir Extrusion (FSE) is a novel process designed to directly recycle machining chips. An experimental campaign was carried out on AZ31 milling chips using variations in extrusion ratio, force and tool rotation rate. The process mechanics were studied and correlated to the material flow, which was elucidated through use of a copper marker. A 3D, Lagrangian, thermo-mechanically coupled dedicated numerical model was set up and validated through temperature measurements. The combination of experimental and numerical results permitted to reconstruct the complex 3D material flow induced by tool rotation and plunge into the extrusion billet chamber.
Using infrared thermography in order to compare laser and hybrid (laser plus MIG) welding processes
2009
International audience; In order to deepen the understanding of the differences between laser and laser-arc hybrid welding, comparisons were undertaken using thermography. The experiments were carried out for a T assembly of aluminium alloy plates. Modelling, based on the finite element method approach, was realized using IR temperature measurements and seam geometry. For a value of the power supply, depicted as a surface source in the hybrid case, agreement was found between simulated and measured temperatures. The arc power supply efficiency value is similar to the usually used value.
A numerical model for Wire integrity prediction in Friction Stir Extrusion of magnesium alloys
2017
Abstract A numerical model for the prediction of the wire quality produced by the novel direct machining chip recycling technique known as Friction Stir Extrusion (FSE) is presented. Wire microstructure and wire integrity have been predicted by embedding in the code the equations enabling the calculation of the Zener-Hollomon parameter as well as the W parameter of the Pivnik-Plata solid bonding criterion. The proposed model, developed for the AZ31 magnesium alloy using the commercial simulation package DEFORM, is 3D Lagrangian, thermo-mechanically coupled with visco-plastic material behavior. The model was first validated against experimental temperature measurements and then used to predi…
Procedure for a Temperature-Traffic Model on Rubberized Asphalt Layers for Roads and Railways
2017
The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballast layer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the average seasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weather situation, Barber’s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessment of improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber (particle size 0.2-4 mm) by weight of the total mix, as…
Methodological Aspects of Infrared Thermography in Human Assessment
2016
Infrared thermography presents some important advantages in the determination of skin temperature, as it is a safe, non-invasive and non-contact technique with wide applications in the field of sports sciences. Like many others techniques, valid measurement in thermography requires following strict methodological steps from data acquisition to analyses and interpretation. In this chapter, we discuss the methodological aspects that must be taken into account when acquiring thermic images, along with some practical examples and recommendations based on the current literature.
Occupational Heat Exposure and Breast Cancer Risk in the MCC-Spain Study.
2021
Background: Mechanisms linking occupational heat exposure with chronic diseases have been proposed. However, evidence on occupational heat exposure and cancer risk is limited. Methods: We evaluated occupational heat exposure and female breast cancer risk in a large Spanish case-control study. We enrolled 1,738 breast cancer cases and 1,910 frequency-matched population controls. A Spanish job exposure matrix, MatEmEsp, was used to assign estimates of the proportion of workers exposed (P greater than or equal to 25% for at least one year) and work time with heat stress (wet bulb globe temperature ISO 7243) for each occupation. We used three exposure indices: ever vs. never exposed, lifetime c…
Thermosensory mapping of skin wetness sensitivity across the body of young males and females at rest and following maximal incremental running
2019
Key points: Humans lack skin receptors for wetness (i.e. hygroreceptors), yet we present a remarkable wetness sensitivity. Afferent inputs from skin cold-sensitive thermoreceptors are key for sensing wetness; yet, it is unknown whether males and females differ in their wetness sensitivity across their body and whether high intensity exercise modulates this sensitivity. We mapped sensitivity to cold, neutral and warm wetness across five body regions and show that females are more sensitive to skin wetness than males, and that this difference is greater for cold than warm wetness sensitivity. We also show that a single bout of maximal exercise reduced the sensitivity to skin wetness (i.e. hyg…
Analysis of cold activation of the contact system in hereditary angioedema with normal C1 inhibitor.
2021
Hereditary angioedema (HAE) attacks are caused by excessive activation of the contact system. Understanding how the contact system is activated in HAE, especially in patients with normal C1 inhibitor (HAEnCI), is essential to effectively treat this disease. Contact system activation involves the cleavage of several proteins including Factor XII (FXII), high molecular weight kininogen (HK), prekallikrein, sgp120 (ITIH4) and C1 inhibitor (C1-INH) before the subsequent generation of bradykinin that mediates HAE. In this study, we evaluated the fragmentation and enzymatic activity of contact system proteins in HAEnCI plasma samples before and after contact system activation induced by incubatio…