Search results for "PIP"
showing 10 items of 1156 documents
Benzene monitoring by micro-machined sensors with SnO2 layer obtained by using micro-droplet deposition technique
2011
International audience; SnO2 thin layers were deposited by the way of the micro-droplet technique. The sensor substrate consisted of a thin membrane developed on oxidised silicon wafer. The sensing layers were deposited by means of the micro-droplet technique into thin layers of about 100 nm. Such devices were tested for benzene detection. The obtained results showed a very high sensitivity for this chemical compound since 500 ppb were detected. The results presented in this paper were not focused on the reactional mechanism of benzene detection but rather on the development of a cheap and sensitive sensor using sol-gel and micro-droplet processes. Since these layers were elaborated using s…
Advanced numerical models for the thermo-mechanical-metallurgical analysis in hot forging processes
2013
In the paper a literature review of the numerical modeling of thermo-mechanical-metallurgical evolutions of a metal in hot forging operations is presented. In particular models of multiaxial loading tests are considered for carbon steels. The collected examples from literature regard phases transformations, also martensitic transformations, morphologies evolutions and transformation plasticity phenomena. The purpose of the tests is to show the correlation between the mechanical and the metallurgical behavior of a carbon steel during a combination of several types of loads. In particular a few mechanical tests with heat treatment are analyzed. Furthermore, Ti-6Al-4V titanium alloy is conside…
Induced roughness in thin films of smectic-C* elastomers
2002
The surface topography of a thin homeotropically oriented film of ferroelectric smectic-C* elastomer is studied by atomic force microscopy. We find that when the film is mechanically stretched, its surface becomes increasingly rough, in proportion to the applied strain. The effect depends strongly on the nature of crosslinks forming the elastomer network. The r.m.s. roughness correlations show a consistent trend [h(x) − h(0)]21/2 ~ (x/ξ)0.5. We introduce a theoretical model assuming that random disorder in the smectic tilt angle is induced by deformations via the coupling of mesogens to the elastic network. The model describes the observed power law and gives a prediction for the correlatio…
Investigation of self-healing mechanism on galvanized steels cut edges by coupling SVET and numerical modeling
2008
Local cathodic inhibition has been observed on the cut-edge of galvanized steel immersed in 0.03 M NaCl solution using the scanning vibrating electrode technique. The current distribution results indicate that cathodic inhibition occurs in a limited spatial zone located between the cathodic sites on the steel and the anodic sites on the exposed zinc surface. The experimental current distributions are compared with the results of numerical simulations that show the specific diagnostic features for the detection of cathodic inhibition from scanning vibrating electrode technique (SVET) data so as to distinguish the zero current regions from experimental artifacts due to the lateral resolution …
Effect of bleaching agents on sealing properties of different intraorifice barriers and root filling materials
2012
Objective: To evaluate the effect of intracoronal bleaching agents on the sealing properties of different intraorifice barriers and root filling materials. Study Design: The root canals of extracted human premolars (n=180) were prepared by using System GT rotary files and filled with either gutta-percha+AH Plus or Resilon+Epiphany sealer. In both groups, the coronal 3mm of root filling was removed and replaced with one of the following materials applied as intraorifice barriers (n=30/group): 1. ProProot-MTA; 2. Conventional Glass ionomer cement; and 3. Hybrid resin composite. In each subgroup, intracoronal bleaching was performed using either sodium perborate with distilled water or 35% hyd…
On the Use of L-shaped Granular Chains for the Assessment of Thermal Stress in Slender Structures
2014
Slender beams subjected to compressive load are common in civil engineering. The rapid in-situ measurement of this stress may help preventing structural anomalies. In this article, we describe the coupling mechanism between highly nonlinear solitary waves (HNSWs) propagating along an L- shaped granular system and a beam in contact with the gran- ular medium. We evaluate the use of these waves to measure stress in thermally loaded structures and to estimate the neutral temperature, i.e. the temperature at which the stress is null. We investigate numerically and experimentally one and two L- shaped chains of spherical particles in contact with a prismatic beam subjected to heat. We find that …
Review of acoustic methods for space charge measurement
2015
In the last decade, due to the increased use of direct current, the space charge accumulation phenomenon has reached more interest. In this regard, several non-destructive measurement systems were used. In particular, for solid dielectrics, the acoustic methods have had greater success. This review presents a brief historical evolution of the Pulse Electro- Acoustic (PEA) method, describing the working operation, the thicknesses analyzed and the spatial resolution for the different configurations of the PEA cell. The Pressure Wave Propagation (PWP) method in both configurations Piezo-PWP and Laser Induced Pressure Pulse (LIPP) is also described.
The inclination effect on the performance of water-filled heat pipes
1991
Abstract Heat pipes have been used in wide ranges of applications today including solar engineering. During this research study, the inclination dependent performance of water filled heat pipes was investigated both theoretically and experimentally for solar energy applications. The results showed that the performance of water-filled heat pipes are strongly dependent on the inclination and the heat source temperatures. As a general result, the heat transfer capability of water filled heat pipes is reduced dramatically below a 45° tilt angle.
Temperature Measurements as a Method for Monitoring Ropes
2020
Due to an increasing demand for operation at sea depths as low as 3000 m and under, the use of fibre ropes for offshore application in deep sea lifting and mooring is increasing. Consequently, improved knowledge is required regarding these ropes’ thermo-mechanical properties and how these properties change as the rope is being used. This paper presents a 2D model of heat transport in the axial and radial directions along a 28 mm diameter fibre rope typically used for offshore applications. The model is combined with temperature measurements during heating and cooling of the rope, using both thermocouples and a thermal camera. Measurements are performed both on a new rope and on a used that …
EFFECT OF SHAPE ON POTATO AND CAULIFLOWER SHRINKAGE DURING DRYING
2000
ABSTRACT Shrinkage of potato cubes, parallelepipeds and cylinders was addressed during drying. A basic methodology by using image analysis was set-up in order to measure and monitor geometrical changes along the drying process. Both measurements by image analysis and directly with a calliper were carried out. Results from both methods showed a good agreement with no bias. Particle shape was found to influence shrinkage in a different way according to the axis. In fact the larger dimension shrinks less than the shorter one. This could be linked to the influence of the core drying in shrinkage. Experiments were also carried out for cauliflower stems. The difference in shrinkage between direct…