Environmentally-Extended Input-Output analyses efficiently sketch large-scale environmental transition plans -- illustration by Canada's road industry

Industries struggle to build robust environmental transition plans as they lack the tools to quantify their ecological responsibility over their value chain. Companies mostly turn to sole greenhouse gas (GHG) emissions reporting or time-intensive Life Cycle Assessment (LCA), while Environmentally-Extended Input-Output (EEIO) analysis is more efficient on a wider scale. We illustrate EEIO analysis usefulness to sketch transition plans on the example of Canada s road industry - estimation of national environmental contributions, most important environmental issues, main potential transition levers of the sector, and metrics prioritization for green purchase plans). To do so, openIO-Canada, a new Canadian EEIO database, coupled with IMPACT World plus v1.30-1.48 characterization method, provides a multicriteria environmental diagnosis of Canada s economy. The road industry generates a limited impact (0.5-1.8 percent) but must reduce the environmental burden from material purchases - mainly concrete and asphalt products - through green purchase plans and eco-design and invest in new machinery powered with cleaner energies such as low-carbon electricity or bioenergies. EEIO analysis also captures impacts often neglected in process-based pavement LCAs - amortization of capital goods, staff consumptions, and services - and shows some substantial impacts advocating for enlarging system boundaries in standard LCA. Yet, pavement construction and maintenance only explain 5 percent of the life cycle carbon footprint of Canada s road network, against 95 percent for the roads usage. Thereby, a carbon-neutral pathway for the road industry must first focus on reducing vehicle consumption and wear through better design and maintenance of roads (...

Comparing optical sensing using slab waveguides and total internal reflection ellipsometry

The sensitivity of the effective refractive index of slab waveguide sensors to variations in the refractive index of the cladding is compared to that of the ellipsometric parameters. The changes of the effective refractive index of a waveguide and the ellipsometric parameter\Delta, due to the index change of the cladding, were derived and plotted as a function of the guiding layer thickness and with the index of the cladding. It is found that these changes almost have the same overall feature but the ellipsometric parameters showed considerable higher sensitivity than the effective index of the conventional waveguide optical sensors

Development and construction of rotating polarizer analyzer ellipsometer

A detailed mathematical derivation and an experimental characterization of one to two ratio rotating polarizer analyzer ellipsometer (RPAE) are presented. The alignment, calibration, and testing of reference samples are also discussed. The optical properties of some known materials obtained by the proposed ellipsometer will be shown and compared to accepted values. Moreover, the constructed ellipsometer will be tested using two ellipsometry standards with different thicknesses

Theoretical spectroscopic scan of the sensitivity of asymmetric slab waveguide sensors

An extensive theoretical analysis is carried out to investigate the variation of the sensitivity of optical slab waveguide sensors with the wavelength of the guided wave. We consider a three-layer waveguide as an optical sensor. The sensitivity for both polarizations of light: s-polarized light (TE) and p-polarized light (TM), is derived using the characteristic equation of the structure. The dispersion of the materials is taken into account to study the sensitivity spectroscopic scan over the near IR-range from 1.2–2 µm. It is found that an optimum wavelength exists for each guiding layer thickness and this optimum value increases linearly with the thickness of the guiding layer

Universal shape law of stochastic supercritical bifurcations: Theory and experiments

A universal law for the supercritical bifurcation shape of transverse one-dimensional (1D) systems in presence of additive noise is given. The stochastic Langevin equation of such systems is solved by using a Fokker-Planck equation leading to the expression for the most probable amplitude of the critical mode. From this universal expression, the shape of the bifurcation, its location and its evolution with the noise level are completely defined. Experimental results obtained for a 1D transverse Kerr-like slice subjected to optical feedback are in excellent agreement.Comment: 5 pages, 5 figure

Rotating polarizer, compensator, and analyzer ellipsometry

In this paper we propose theoretically a set of ellipsometric configurations using a rotating polarizer, compensator, and analyzer at a speed ratio of N 1 ω: N 2 ω: N 3 ω. Different ellipsometric configurations can be obtained by giving different integral values to N 1, N 2, and N 3. All configurations are applied to bulk c-Si and GaAs to calculate the real and imaginary parts of the refractive index of the samples. The accuracies of all ellipsometric configurations are investigated in the presence of a hypothetical noise and with small misalignments of the optical elements. Moreover, the uncertainties in the ellipsometric parameters as functions of the uncertainties of the Fourier coefficients are studied. The comparison among different configurations reveals that the rotating compensator—analyzer configuration corresponds to the minimum error in the calculated optical parameters

Engineered Near and Far Field Optical Response of Dielectric Nanostuctures using Focused Cylindrical Vector Beams

Near- and far-field optical properties of silicon nanostructures under linear polarization (Gaussian beam), and azimuthally or radially focused cylindrical vector beams are investigated by finite-difference time-domain method (FDTD) in Meep open-source software. A python toolkit allowing FDTD simulations in Meep for using those excitation sources is provided. In addition to the preferential excitation of specific electric or magnetic resonance modes as function of the excitation beam polarization, it is shown in the case of spheroids that shape anisotropy affects the resonance wavelength and the dipole orientation of the magnetic or electric dipole mode. For radial or linear polarization, the electric dipole resonance is split by an anapole mode depending on the spheroid symmetry axis with respect to the electric field orientation. Finally, the optical properties in both far-field (scattering pattern) and near-field (electric and magnetic field hot spots) can be tuned by changing the excitation polarization at a fixed wavelength and selecting properly the spheroid shape and dimensions. These numerical simulations can be extended to more complex shapes, or fabrication-friendly nanostructures such as nanocylinders with circular or elliptic sections

Dye-sensitized solar cells using dyes extracted from flowers, leaves, parks, and roots of three trees

In this paper, eleven natural dyes were collected from three trees and used as photosensitizers for dye sensitized solar cells (DSSCs). The cells were fabricated using TiO2 as a semiconducting layer deposited on transparent fluorine doped tin oxide (FTO) conductive glass using doctor blade method. The absorption spectra of the extracts were performed in the spectral range from 400 nm to 750 nm. The JV characteristic curves of all fabricated cells were measured and analyzed. The parameters related to the solar cell performance were determined. Moreover, the impedance spectroscopy of the cell with the best performance was investigated

Electrical properties of organic light emitting diodes with post fabrication heat and electric field treatments

The current work presents post-fabrication heat treatment and a combined external electric field-heat post-fabrication treatments for organic light emitting diodes (OLEDs). The devices were fabricated in the same run with a standard device without annealing for comparison, with an identical structure of ITO/PVK/Rhodamine B/Pb. After depositing the Rhodamine B layer on the PVK film, the samples were thermally annealed at different temperatures before depositing Pb. Some of the samples were thermally annealed without any external electric field while others were treated by an external electric field during heating. It is found that the annealing temperature of PVK/Rhodamine B layers increases the turn-on voltage of the device. On the other hand, in the electric field-heat treatment, the turn-on voltage is observed to decrease and the maximum current density of the device is dramatically enhanced