PASCAL/CNRS

The novel La1-xSrx(Mn1-yCoy)zO3 (LSMCO) films were grown by Pulsed-Injection Metalorganic Chemical Vapor Deposition (PI-MOCVD) technique on different oxide substrates. The structural, transport and magnetic properties of the LSMCO films were investigated in terms of crystal structure, texture, electric and magnetoresistive properties of the films for room temperature applications in magnetic sensing. Additionally, to lattice matchingmismatching approach between the film and the substrate, chemical engineering in form of chemical doping was investigated. A certain Co content (from 0 up to 0.17) was introduced into non-stoichiometric La1-xSrx(Mn1- yCoy)zO3 films (z = 1.15) and revealed that Mn non-stoichiometry as well as Co content, influences the changes of transition from metal to insulator state temperature TMI. For epitaxial films (LSMCO grown on LaAlO3) the transition temperature (TMI) was very close to Curie temperature (Tc – transition from ferromagnetic to paramagnetic state), whereas for nanostructured films (LSMCO on Sapphire and ceramic Al2O3), the transition temperatures were lower in comparison to Tc. It was found, that for all used substrates the transition temperature tends to decrease with the increase of Co-content in the films. The change of magnetoresistance properties with Co-content was observed and revealed highest magnetoresistance values at room temperature for the films with Co-content of ~0.06 up to 2.3 T magnetic field, leading to improved and controlled sensing properties at low magnetic fields.

The paper presents results of numerical and experimental investigations of a new design piezoelectric energy harvester based on a saw-tooth type cantilever array. The proposed energy harvester has multi-modal operation principle and allows to harvest mechanical vibrations energy in narrow frequency range. Moreover, the multi-modal operation principle of the harvester enable summation of bending strains of several cantilevers and allows to improve efficiency of the harvester. The proposed multi-modal energy harvester consist of four cantilevers that are connected rigidly to each other at 30° angles. Cross-sections of the cantilevers were modified by cylindrical gaps in order to increase bending strain. Seismic masses were placed at each corner of the harvester in order to reduce values of natural frequencies and to create additional rotation moment. Numerical investigation revealed that the energy harvester has five resonance frequencies in the range from 20 Hz to 135 Hz. The numerical investigation of electrical characteristics showed that voltage density of 48.39 mV/mm3 and energy density of 61.25μJ/mm3 was obtained. Experimental investigations confirmed the results of numerical investigation and showed that voltage and energy densities reached 55.65 mV/mm3 and 52.56 μJ/mm3, respectively.

Third-party logistics (3PL) has involved a significant response among researchers and practitioners in the recent decade. In the global competitive scenario, multinational companies (MNCs) not only improve quality of service and increase efficiency, but also decrease costs by means of 3PL. However, the assessment and selection of 3PL is a very critical decision, comprising intricacy due to the existence of various imprecisely based criteria. Also, uncertainty is an unavoidable part of the information in the decision-making process and its importance in the selection process is relatively high and needs to be carefully considered. Consequently, incomplete and inadequate data or information may occur among other various selection criteria, which can be termed as a multi-criteria decision-making (MCDM) problem. Interval rough numbers are very flexible to model this type of uncertainty occurring in MCDM problems. Thus this paper presents a new integrated interval rough number (IRN) approach based on the Best Worst Method (BWM) and Weighted Aggregated Sum Product Assessment (WASPAS) method along Multi-Attributive Border Approximation area Comparison (MABAC) to evaluate 3PL providers. The hybrid IRN-BWM based methodology is used for computing the priority weights of criteria while IRN-WASPAS and IRN-MABAC are employed to achieve the final ranking of 3PL providers. A computational study is performed to illustrate the proposed approaches along with a sensitivity analysis on different sets of criteria weight coefficient values to validate the stability of the suggested methodology. Consequently, a comparative analysis of the obtained ranking results with their crisp and fuzzy counterparts is also conducted for checking the reliability of the proposed approach. The results display stability in ranking of alternative results and prove the feasibility of the proposed approach to handle MCDM problems with IRNs.

This paper describes the design, optimization and experimental results of piezoelectric motor that uses the radial mode of excitation of the double rings stator. The main goal of the proposed design is to increase motor performance using d33 ceramic polarization working in the radial mode. The proposed motor can be driven by a simple harmonic signal and used for standard piezoceramic rings. The stator consists of four parts: metal ring, Alumina (Al2O3) ring and double piezoceramic rings. The design is optimized for laser cutting machine and is cost effective for manufacturing. The main application field of the proposed motor is micro-air vehicles (μAV). The finite element method (FEM) was used to define the structural and electrical boundary condition for the symmetrical coplanar trimorph piezoelectric actuator. The results of the numerical calculations after geometry optimization, some experimental results and mechanical properties of the ultrasonic motor are presented in this paper as well.

A multi-channel cyclone is a new-generation cleaning device, which purifies a gas flow by removing fine dispersion solid particles of 2 μm and larger in diameter from it. An aggressive dispersed gas flow can be formed under various conditions, for example, in combustion and processing of various products such as drying of chemical compounds, etc., at high temperature and/or high humidity. Multi-channel cyclones of a new generation have a number of advantages over the most widely used equipment for separating the particulate matter from the air flow such as electrostatic and bag filters, which are rather expensive, difficult to maintain and to be used for separating sticky and moist particles from the aggressive gas flow. The paper examines wood and lignin solid particles of different nature and properties present in a gas-vapour flow. Their adhesion and cohesion, depending on the time of the multi-channel cyclone operation aimed at purifying a dusted gas-vapour flow at high gas-vapour temperature and humidity are investigated. The research is aimed at determining the optimal separation efficiency and the aerodynamic parameters of a multi-channel cyclone and their variation by creating an aggressive dispersed gas flow. It assesses the detrimental effect of the deposition of wood and lignin solid particles on its interior surfaces, their cohesion and adhesion and clogging the system. The efficiency of the cyclone's operation is investigated for the flow, moving at medium rates and containing solid particles of various sizes. The highest cyclone's efficiency is determined for its separation of medium- and small-size solid particles. The theoretical study of kinematic and dynamic gas flow viscosity and the calculation of its coefficients as well as the dew point temperature of the flow are performed and the relationships between them are determined. The obtained results are presented and some recommendations for improving the structure of a multi-channel cyclone for separating sticky and moist particles from a humid and hot gas flow are provided.

A new small size linear type piezoelectric inertia-friction actuator has been developed. The actuator is self-inertia type and operation principle is based on the impact drive. Piezoelectric actuator has simple designand consists of four rectangular bimorph piezoelectric plates fixed in two metal holders that are connectedby the two springs. Actuator can operate as self-moving slider on the clamped carbon fiber reinforcedplastic rod or it can be clamped to drive the rod. Size of the actuator is 8 × 8.5 × 5.6 mm. Excitation of theactuator can be carried out by single saw tooth or rectangular pulse type signal. Bidirectional motion of theslider is achieved by changing phase of the saw tooth electrical signal by or duty ratio of the rectangularpulse signal. Numerical investigation of the piezoelectric actuator was performed to analyze naturalfrequencies, modal shapes and response of the actuator to the different excitation signals. A prototypepiezoelectric actuator was made and operating principle of the actuator was validated. Measurementsof electrical and mechanical output characteristics were performed. The maximum no load velocity ofthe slider reaches 40.376 mm/s with driving voltage of 40 V. Actuator achieves maximum thrust force of0.21 N with the same input voltage.

Investigation of a novel design inertial type piezoelectric motor is presented in the paper. Research was performed to validate operation principle and to investigate dynamic characteristics of the motor. Motor has simple design and consist of rectangular bronze stator, clamping frame, eight lead zirconate titanate (PZT) plates and a conical rotor. PZT plates are glued on the stator from both sides and are used to excite secondin-plane bendingmode. Excitationofthemotor is carriedout by two saw-toothsignals withphases shifted by . Rotor is located at the center of the stator. Rotation motion of the rotor is based on stickslip operation principle. Proposed piezoelectric motor is flat and can be used for the applications where space and mounting volume are critical. Numerical investigation ofthe piezoelectric motor based on finite elements method was performed in order to obtain natural frequency and modal shape of the stator, to investigate dynamic characteristics and to validate operation principle of the motor. Proper geometric parameters of the stator were obtained by solving optimization problem. A prototype of the motor was made and investigations of the mechanical, thermal and electrical characteristics were performed. The results of the numerical and experimental investigations are discussed.

Variable angle total internal reflection ellipsometry (TIRE) has been utilized to reveal anisotropy in the optical response of fragmented antibody (frag-Ab) monolayer. Optical anisotropy has been taken into account in determination of optical constants of an organic layer. The orientation of frag-Ab on the surface has been characterized by using the uniaxial model in the analysis of TIRE data. Regression results have shown that the largest dimension of frag-Ab molecule (11.5 nm) is oriented parallel to the gold surface with a slight tilt (13◦). Due to the tilt, the distance between the recognition sites of frag-Ab and the gold surface increases resulting in an enhanced reactivity of the molecules and better steric accessibility.