Search results for "CONTACT"

Design of a narrow-band filter based on the Brewster phenomenon for microwave applications

2017

A high-efficiency narrow-band filter based on a Dielectric Frequency-Selective Surface (DFSS) has been predicted theoretically for oblique plane-wave incidence. A DFSS showing total reflection at a frequency of 10.5 GHz, based on the Brewster phenomenon for TM polarization, has been designed with a single dielectric grating, showing extremely low-reflectance sidebands adjacent to the resonance peak. The angular and spectral response of the designed filter has been studied. In addition, dielectric ohmic losses have been accounted for in this structure. This work was supported by the Agencia Estatal de Investigación (AEI) and by the Unión Europea through the Fondo Europeo de Desarrollo Region…

3D Data Acquisition and Numerical Analysis of a Footwear in Walking

2004

The aim of the paper is to set a procedure to study the load history of a footwear during a step with non-linear FE analysis. The geometric model tested was reconstructed from a real shoe by means of Reverse Engineering process, starting from dense point clouds acquired by non-contact scanning system. For each phase of the walk, the pressure values are obtained by a pressure distribution platform when tester is walking along the platform. The Finite Element model is easily generated by Hypermesh software using the CAD model. Ansys software is used to perform non-linear analyses. The procedure can be employed for improving the product performance in terms of durability, flexibility and comfo…

Contact between the components of a knee prosthesis: numerical and experimental study

2012

The aim of this work is the analysis of the contact area in a knee prosthesis using two different approaches. In particular, the interface between the femoral component and the polyethylene insert has been studied both numerically and experimentally. The interest in studying the contact area is related to the fact that the wear of the polyethylene insert, due to the high contact pressures, represents one of the major causes of failure of the total knee prosthesis. The possibility to evaluate the contact area at different loads and mutual position between femur and tibia is, therefore, of fundamental importance to study the service life of a prosthesis and to improve its performance. The fin…

Frictionless contact formulation by mathematical programming technique

2011

The object of the paper concerns a consistent formulation of the classical Signorini's theory regarding the frictionless unilateral contact problem between two elastic bodies in the hypothesis of small displacements and strains. A variational approach, employed within the symmetric Boundary Element Method, leads to an algebraic formulation based on nodal quantities. The contact problem is decomposed into two sub-problems: one is purely elastic, and the other pertains to the unilateral contact condition alone. Following this methodology, the contact problem, faced with symmetric BEM, is characterized by symmetry and sign definiteness of the coefficient matrix, thus admitting a unique solutio…

Safety Evaluation of Food contact paper and board using Chemical Tests and in vitro Bioassays-The role of known and unknown substances

2010

International audience; In vitro toxicological tests has have been proposed as an approach to complement the chemical safety assessment of food contact materials, particularly those with a complex or unknown chemical composition such as paper and board. An EU 5th framework program project “BIOSAFEPAPER – Application of bioassays for safety assessment of paper and board for food contact” specially focused on the application of biotests to paper and board. The project included both chemical characterization and toxicological testing of a representative number of paper and board extracts prepared according to the proposed end use (wet, fatty and dry food contact). Among the concerns addressed …

Baltu filoloģija, 8

1999

Membrane protein integration into the endoplasmic reticulum

2011

Most integral membrane proteins are targeted, inserted and assembled in the endoplasmic reticulum membrane. The sequential and potentially overlapping events necessary for membrane protein integration take place at sites termed translocons, which comprise a specific set of membrane proteins acting in concert with ribosomes and, probably, molecular chaperones to ensure the success of the whole process. In this minireview, we summarize our current understanding of helical membrane protein integration at the endoplasmic reticulum, and highlight specific characteristics that affect the biogenesis of multispanning membrane proteins.

Targeting and membrane insertion into the endoplasmic reticulum membrane of Saccharomyces cerevisiae essential protein Rot1

2010

Rot1 is an essential yeast protein that has been related to cell wall biosynthesis, actin cytoskeleton dynamics and protein folding. Rot1 is an N -glycosylated protein anchored to the nuclear envelope–endoplasmic reticulum (ER) membrane by a transmembrane domain at its C-terminal end. Rot1 is translocated to the ER by a post-translational mechanism. Here, we investigate the protein domain required to target and translocate Rot1 to the ER membrane. We found that several deletions of the N-terminal region of Rot1 prevented neither membrane targeting nor the insertion of this protein. Interestingly, we obtained the same results when different truncated forms in the C-terminal transmembrane dom…

Los contactos internacionales de la arqueología valenciana en el periodo 1900-1936

2017

En las dos primeras décadas del siglo XX la arqueología valenciana estuvo impulsada por aficionados y coleccionistas que llevaron a cabo diversos descubrimientos y excavaciones. En este periodo varios investigadores extranjeros exploraron numerosos yacimientos valencianos sin otro contacto que algunos de estos aficionados. En 1927, la concurrencia de la fundación del Servicio de Investigación Prehistórica (SIP) en Valencia por Isidro Ballester y la llegada a la universidad del profesor Luis Pericot fueron dos hechos determinantes en la proyección internacional de la arqueología valenciana. El SIP pasó a ser un órgano estable de interlocución con los investigadores foráneos, y sus publicacio…

The behavioral responses of the egg parasitoid Ooencyrtus telenomicida to semiochemicals from first and second trophic level

2009

In this study the responses of females of the egg parasitoid Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae) to volatile and contact chemicals from its host Nezara viridula (L.) (Heteroptera: Pentatomidae) and from host plant Solanum lycopersicum L. were investigated in a Y-tube olfactometer and in open arena. Our results in the Y-tube olfactometer tests showed that: (1) female wasps were attracted to volatiles from adult host virgin male and to volatiles from a host mated female, showing a clear preference for the volatiles emitted from the former; volatiles from host virgin females did not attract O. telenomicida females; (2) only volatiles produced by host-damaged plant com…