Search results for "LONG"
showing 10 items of 3969 documents
Influence of laser beam profile on the generation of ultrasonic waves
2011
The different ultrasonic fields generated in metallic materials by a laser beam with flat and Gaussian profile are investigated experimentally and using the finite element method (FEM). A high power laser beam irradiating a solid surface produces elastic waves with a mechanics that depends on many parameters, including the profile of the laser beam. The influence of the beam profile is investigated with the FEM analysis, considering the temperature dependence of material properties.
Theoretical and Experimental Research on Mechanical Behavior of Layered Composites Laminates
2014
The aim of the research of the experiment was to determine the mechanical characteristics of the composite layered material. There has been two types of experimental tests i.e. test for determining the tensile modulus of elasticity of the material, the maximum voltage and the elongation at break of the material. The second type of test is the flexural test was intended to determine the maximum load that the breaking is produced by bending.
Novel method of phosphorescent strontium aluminate coating preparation on aluminum
2018
This work was supported by the ERDF , European-Union Project No. 1.1.1.1/16/A/182 .
Research Regarding the Influence of Raw Material and Knitted Fabric Geometry on the Tensile Strength and Breaking Elongation
2016
Abstract The main purpose of this research paper is to increase the performance of knitting process during socks manufacturing by choosing the right knitted fabric geometry and raw material. On the other side, tests results show the wear resistance regarding mechanical properties like tensile strength and breaking elongation of knitted fabrics for socks. To obtain samples knitted fabric were used several types of some classic yarns, which already use to obtain socks organic also another type of yarns less used: cotton, organic cotton, bamboo viscose, soy + cotton, Tencel. From these yarns the following knitted fabric geometry were obtained: plated single jersey, plated ribb 4:2 and plated p…
Photo-oxidative degradation of poly(ethylene-co-vinyl acetate)/nisin antimicrobial films
2012
The photo-oxidative behaviour of different antimicrobial blown films based on poly (ethylene-co-vinyl acetate) (EVA) was studied. In particular, two samples of EVA containing different level of vinyl acetate comonomer (namely 14% and 28%) were used as matrices while nisin at different concentrations was used as antimicrobial agent. The degradation was followed by analyzing the changes in the spectroscopic behaviour and of the elongation at break measured in tensile tests. Moreover, changes in the antimicrobial activity of the films were followed by measuring the inhibition halo in agar diffusion tests. The results indicate that nisin acts as an excellent UV stabilizer for both samples of EV…
Health monitoring of high performance composite pressure vessels,
2018
International audience; The most important form of damage in carbon fiber reinforced composite pressure vessels is the failure of the fibers however the rate of fiber failure is controlled by the viscoelastic nature of the matrix, which determines overall in-service lifetimes. This type of damage is very different from that encountered with metal pressure vessels and requires a detailed understanding in order to ensure reliability. Innovative proof testing methods based on these processes are necessary. The damage processes and the means of quantifying them are discussed. Their reliability under pressure over periods of decades is analyzed. Intrinsic safety factors linked directly to the pr…
Temporal patterns in immune responses to a range of microbial insults (Tenebrio molitor).
2008
8 pages; International audience; Much work has elucidated the pathways and mechanisms involved in the production of insect immune effector systems. However, the temporal nature of these responses with respect to different immune insults is less well understood. This study investigated the magnitude and temporal variation in phenoloxidase and antimicrobial activity in the mealworm beetle Tenebrio molitor in response to a number of different synthetic and real immune elicitors. We found that antimicrobial activity in haemolymph increased rapidly during the first 48h after a challenge and was maintained at high levels for at least 14 days. There was no difference in the magnitude of responses …
Pappus type theorems for motions along a submanifold
2004
Abstract We study the volumes volume( D ) of a domain D and volume( C ) of a hypersurface C obtained by a motion along a submanifold P of a space form M n λ . We show: (a) volume( D ) depends only on the second fundamental form of P , whereas volume( C ) depends on all the i th fundamental forms of P , (b) when the domain that we move D 0 has its q -centre of mass on P , volume( D ) does not depend on the mean curvature of P , (c) when D 0 is q -symmetric, volume( D ) depends only on the intrinsic curvature tensor of P ; and (d) if the image of P by the ln of the motion (in a sense which is well-defined) is not contained in a hyperplane of the Lie algebra of SO ( n − q − d ), and C …
Assessing the competence learning to learn: a methodological proposal
2012
En este artículo se presenta un procedimiento para diseñar instrumentos para evaluar la competencia de Aprender a Aprender. Analizamos la secuencia de trabajo y los conceptos implicados. Se trata de una línea de trabajo que pretende diseñar instrumentos de evaluación referidos a estándares, para evaluar las competencias básicas en la educación obligatoria, y las genéricas o transversales en las titulaciones de grado universitarias (el sistema de instrumentos para universitarios se denomina ESCOGE). Se ilustra la reflexión acerca de esta propuesta con la definición teórica realizada para el diseño de instrumentos que permitan evaluar esta competencia en egresados universitarios del área de C…
Measuring educational participation and attainment over the life course
2019
International audience