Do new and relocating firms have different preferences for accessibility?

Accessibility is one of the most important factors in a location choice decision of a firm. However, new and relocated establishments can value accessibility differently. Research papers differences of accessibility preferences between creations and relocations are scarce. In this paper, we examine these differences in an intraurban setting, the Lyon urban area. We rely on discrete choice models and data for more than 43,000 creations and 11,000 relocations during 2005–2011 from eight economic sectors. Results demonstrate that the effect of accessibility differs between creations and relocations of the same economic sector. This difference depends on the type of the economic activity of the sector.     

A cathodoluminescence study of boron doped {111}-homoepitaxial diamond films

In this work we use cathodoluminescence (CL) at liquid helium temperature to investigate the boron incorporation in {111}-homoepitaxial diamond films, grown outside the visible plasma ball by the Microwave plasma-assisted chemical vapor deposition (MPCVD) technique. The boron concentration of this set of films covers the whole possible doping range divided into four parts: Low doping (5 × 10¹⁶ < [B] < 1.5 × 10¹⁹ cm^? 3), high doping (1.5 × 10¹⁹ < [B] < 3 × 10²⁰ cm^? 3), heavy doping (3 × 10²⁰ < [B] < 2 × 10²¹ cm^? 3), and phase separation range ([B] > 2 × 10²¹ cm^? 3). The phase separation occurs for very high boron concentrations, between the diamond phase (sp³ carbon) and the other components of the layer, namely sp² carbon and boron. A part of them is accumulated outside the diamond lattice.This detailed cathodoluminescence investigation of {111}-homoepitaxial diamond films has led to determining the doping range of the films and following the evolution of their crystalline quality when the boron concentration increases. In addition, a comparison between {111} and {100} films in the same doping ranges has been undertaken.     

n-type phosphorus-doped polycrystalline diamond on silicon substrates

The microwave plasma-assisted deposition of reproducible and homogeneously n-type phosphorus-doped polycrystalline (microcrystalline) diamond films on silicon substrates is described. The phosphorus incorporation is obtained by adding gaseous phosphine (PH₃) to the gas mixture during growth. The low CH₄/H₂ ratio (0.15%) and the use of the same growth parameters as for homoepitaxial {111} films, led to a good crystalline quality of the continuous polycrystalline diamond layers, confirmed by SEM images and Raman spectroscopy measurements.Secondary-ion mass spectrometry (SIMS) analysis measured a phosphorus concentration [P] of at least 7 × 10¹⁷ cm^− 3. Cathodoluminescence spectroscopy in our P-doped polycrystalline films shows a phosphorus bound exciton (BE^TO_P) peak between 5.142 and 5.181 eV. Cathodoluminescence and Raman-effect spectroscopy confirmed the improvement of the crystalline quality of our films as well as a decrease in the intensity of the internal strain when the grain size was decreased. Cathodoluminescence imaging and SIMS depth profile of phosphorus demonstrated a very good homogeneity of phosphorus incorporation in the films.     

Time and thermal stability improvement of polyethylene ferroelectrets

Ferroelectrets with good piezoelectric coefficients have been produced based on cellular polyethylene (PE) via extrusion film blowing. The quasi-static piezoelectric coefficient (d₃₃) value obtained (935 pC/N) was well above typical values for cellular polypropylene (PP) considered as the workhorse of piezoelectric polymers. Here, a focus was made on increasing the time and thermal stability of cellular PE piezoelectric activity. To do so, specific thermal treatments were applied on the films to improve their microstructure. First, films crystallinity was increased via thermal annealing at 80 °C for 5 min leading to a 32% increase of the initial d₃₃ value as well as its time stability. However, thermal treatment did not give a significant thermal stability improvement because the treated films almost completely lost their piezoelectric activity (96%) at 80 °C. Therefore, the films were treated with orthophosphoric acid resulting in substantial charge stability improvements, especially at higher temperature. Overall, it was possible to increase the continuous service temperature (CST) of PE ferroelectrets from 40 to 80 °C, which is similar to the typical CST of PP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47646.     

Misalignment controller in wireless battery charger for electric vehicle based on MPPT method and metaheuristic algorithm

This paper focuses on applying a wireless power transfer WPT technology in an electric vehicle battery charger. The wireless charger system is based on the principle of resonance inductive coupling power through a coreless transformer. The WPT system is considered as a multi parameter and multi constrained nonlinear system. The main contribution in this paper is the use of PSO and GA metaheuristic algorithms in the optimization of a transformer design regarding the impact of a lateral misalignment and the separation distance between the primary and secondary coils. To find the best global solution which is considered as the maximum efficiency in the complex system, both algorithms are compared. A perturbation-and-observation-based tracking system is developed through an efficiency sensing system to act on the misalignment issue and the car position. An additional PSO controller is performed to control the duty cycle of the boost converter in order to follows the maximum efficiency operating points of a WPT system. The discrepancy is the use of the resonant inductive coupling as a source of the MPPT so as to perturb the car position and observe the transferred. Furthermore, the modeling of a contactless transformer is optimized using metaheuristic algorithm.     

Kinetic and equilibrium study for the sorption of cadmium(II) ions from aqueous phase by eucalyptus bark

The efficiency of eucalyptus bark as a low cost sorbent for removing cadmium ions from aqueous solution has been investigated in batch mode. The equilibrium data could be well described by the Langmuir isotherm but a worse fit was obtained by the Freundlich model. The five linearized forms of the Langmuir equation as well as the non-linear curve fitting analysis method were discussed. Results show that the non-linear method may be a better way to obtain the Langmuir parameters. Maximum cadmium uptake obtained at a temperature of 20 degrees C was 14.53mgg(-1). The influence of temperature on the sorption isotherms of cadmium has been also studied. The monolayer sorption capacity increased from 14.53 to 16.47 when the temperature was raised from 20 to 50 degrees C. The DeltaG degrees values were negative, which indicates that the sorption was spontaneous in nature. The effect of experimental parameters such as contact time, cadmium initial concentration, sorbent dose, temperature, solution initial pH, agitation speed, and ionic strength on the sorption kinetics of cadmium was investigated. Pseudo-second-order model was evaluated using the six linear forms as well as the non-linear curve fitting analysis method. Modeling of kinetic results shows that sorption process is best described by the pseudo-second-order model using the non-linear method. The pseudo-second-order model parameters were function of the initial concentration, the sorbent dose, the solution pH, the agitation speed, the temperature, and the ionic strength.     

Integrated ion exchange mixed bed with reverse osmosis and nanofiltration for isolation of neutral dissolved organic matter from natural waters

The aim of this study was to isolate the neutral dissolved organic matter (NDOM) and the low molecular weight neutrals (LMWN) from natural waters. The coupling of an ion exchange mixed bed (IEXMB) with reverse osmosis (RO) and nanofiltration was the main hypothesis. IEXMB removed charged species, while the neutral molecules were isolated in the demineralised water and then concentrated by RO without any osmotic pressure or fouling limits. Neutrals isolation and unlimited concentration, gives this paper its originality. The nanofiltration (NF) step allows for the isolation of the LMWN. The studied reservoir water NDOM and LMWN represented respectively 35% of the dissolved organic matter (DOM) and 34% of the NDOM. Aromatic compounds were found in both fractions. The UV254 absorbance measured before and after the IEXMB evidenced the water quality ‘signature’. IEX has never been studied as fractionation method of DOM. This IEXMB approach is thus quite novel.     

Zinc-Blende MnTe Under Pressure: Structural,Mechanical, and Optical Properties from Ab Initio Calculation

We present first-principles studies of structural, mechanical, and optical properties of zinc blende MnTe using the pseudopotential plane-wave method within the local density approximation. The effect of hydrostatic pressure on investigated properties has been examined and discussed. At zero pressure, our results are found to agree reasonably well with those reported in the literature. The generalized elastic stability criteria showed that the material of interest is mechanically stable in all the studied pressure ranges. Applied pressure is found to shift all optical spectra under consideration, giving new optical parameters.     

On the reduction of the non-diamond phase in nanocrystalline CVD diamond films

We present photocurrent spectra of nominally undoped nanocrystalline diamond (NCD) films grown on glass substrates by hot filament (HF) and microwave (MW) plasma enhanced chemical vapor deposition (CVD). The spectra were measured in a broad optical range (200–2000 nm) by dual-beam photocurrent spectroscopy (DBP) and Fourier-transform photocurrent spectroscopy (FTPS) in amplitude modulated step scan mode. The NCD films with carefully oxidized surface show photosensitivity and high dark resistivity. Unlike single crystal type IIa diamond with the photonization threshold at 5.5 eV, the photocurrent spectra of NCD films are dominated by the “non-diamond phase” with the photo-ionization threshold at about 0.8 eV. Some HF CVD samples have lower sub-band gap absorption (non-diamond phase contamination). The non-diamond phase content increases after annealing at elevated temperature. The non-diamond phase content can be reduced by exposing NCD to hydrogen plasma at temperature below 350 °C.     

Removal of mercury(II) from aqueous media using eucalyptus bark: Kinetic and equilibrium studies

In this study, eucalyptus camaldulensis bark, a forest solid waste, is proposed as a novel material for the removal of mercury(II) from aqueous phase. The operating variables studied were sorbent dosage, ionic strength, stirring speed, temperature, solution pH, contact time, and initial metal concentration. Sorption experiments indicated that the sorption capacity was dependent on operating variables and the process was strongly pH-dependent. Kinetic measurements showed that the process was uniform and rapid. In order to investigate the mechanism of sorption, kinetic data were modeled using the pseudo-first-order and pseudo-second-order kinetic equations, and intraparticle diffusion model. Among the kinetic models studied, the pseudo-second-order equation was the best applicable model to describe the sorption process. Equilibrium isotherm data were analyzed using the Langmuir and the Freundlich isotherms. The Langmuir model yields a much better fit than the Freundlich model. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy, and entropy of sorption. The maximum sorption capacity was 33.11 mg g⁻¹ at 20 °C and the negative value of free energy change indicated the spontaneous nature of sorption. These results demonstrate that eucalyptus bark is very effective in the removal of Hg(II) from aqueous solutions.