PV/batteries sizing and energy dispatching using Continuous Petri Net

Electrification of isolated area is commonly ensured by autonomous power installation including renewable energy sources. Many software tools are available to size such installations. These tools refer to the daily energy need and the site global renewable potential which leads to inaccurate and wasteful sizing. This paper presents an alternative tool based on the energy consumption and the daily loads profile to compute the size of a standalone PV/batteries system installed in an isolated chalet in Sfax, Tunisia. Obtained results are compared to those provided by PVsyst sizing tool to confirm the proposed algorithm effectiveness. Referring to obtained results, an assessment is proposed to dispatch energy between connected autonomous installations to cover the need of some houses by energy surplus offered by neighbors. A Continuous Petri Net (CPN) is used to model the energy flow between houses.     

Runtime Support for Parallelization of Data-Parallel Applications on Adaptive and Nonuniform Computational Environments

In this paper we discuss the runtime support required for the parallelization of unstructured data-parallel applications on nonuniform and adaptive environments. We describe several optimization techniques for fast remapping of data and for reducing the amount of communications between machines when the computational load on the machines changes during the execution of data-parallel applications. The approach presented is reasonably general and is applicable to a wide variety of regular as well as irregular applications. We present performance results for the solution of an unstructured mesh on a cluster of workstations.     

Lp norm approaches for estimating voltage flicker

It is important to accurately estimate instantaneous voltage flicker magnitudes and frequencies in order to correctly evaluate voltage fluctuations. Voltage flicker is a problem in electric power quality. Different approaches used to determine the magnitude of the voltage flicker have been presented: measurement methods generally use a flickermeter device. Simulation methods require a computer model of the disturbing load and the flickermeter. Calculation methods necessitate a simplified empirical formula. Estimation algorithms are based on the estimation of the voltage flicker components. In this paper, two models of voltage flicker are discussed: L_p estimation algorithms utilizing L₁, L₂ and L_∞ norms are used to estimate the voltage magnitudes of the flicker signals as well as the fundamental voltage magnitude. The main result is that it is possible to design an L_p estimator to identify flicker frequency and amplitude from time series measurements.     

Three-dimensional core-shell hybrid solar cells via controlled in situ materials engineering

Three-dimensional core-shell organic-inorganic hybrid solar cells with tunable properties are demonstrated via electropolymerization. Air-stable poly(3,4-ethylenedioxythiophene) (PEDOT) shells with controlled thicknesses are rapidly coated onto periodic GaAs nanopillar arrays conformally, preserving the vertical 3D structure. The properties of the organic layer can be readily tuned in situ, allowing for (1) the lowering of the highest occupied molecular orbital level (|ΔE| ～ 0.28 eV), leading to the increase of open-circuit voltage (V(OC)), and (2) an improvement in PEDOT conductivity that results in enhanced short-circuit current densities (J(SC)). The incorporation of various anionic dopants in the polymer during the coating process also enables the tailoring of the polymer/semiconductor interface transport properties. Systematic tuning of the device properties results in a J(SC) of 13.6 mA cm(-2), V(OC) of 0.63 V, peak external quantum efficiency of 58.5%, leading to a power conversion efficiencies of 4.11%.     

Discontinuous Galerkin Finite-Element Method for Simulation of Flood in Crossroads

A numerical solution of the two-dimensional Saint Venant equations is presented for the study of the propagation of the floods through the crossroads of the city. The numerical scheme is a Runge-Kutta discontinuous Galerkin method (RKDG) with a slope limiter. The work studies the robustness and the stability of the method. The study is organized around three aspects: the prediction of the water depths, the location of the right and oblique hydraulic jumps in the crossing, and especially the distribution of the flow discharges in the downstream branches. The objective of this paper was to use the RKDG method in order to simulate supercritical flow in crossroads and to compare these simulations with experimental results and to show the advantage of this RKDG method compared to a second-order finite-volume method. A good agreement between the proposed method and the experimental data was found. The method is then able to simulate the flow patterns observed experimentally and to predict accurately the water depths, the location of the hydraulic jumps, and the discharge distribution in the downstream branches.     

Monte Carlo simulation of III-V material-based MOSFET for high frequency and ultra-low consumption applications

High-mobility III-V heterostructures are emerging and very promising materials likely to fulfil high-speed and low-power specifications for ambient intelligent applications. The main objective of this work is to theoretically explore the potentialities of MOSFET based on III-V materials with low bandgap and high electron mobility. First, the charge control is studied in III-V MOS structures using a Schr?dinger-Poisson solver. Electronic transport in III-V devices is then analyzed using a particle Monte Carlo device simulator. The external access resistances used in the calculations are carefully calibrated on experimental results. The performance of different structures of nanoscale MOS transistor based on III-V materials is evaluated and the quasi-ballistic character of electron transport is compared to that in Si transistors of same gate length.     

Chitosan based edible films and coatings: A review

Chitosan is a biodegradable biocompatible polymer derived from natural renewable resources with numerous applications in various fields, and one of which is the area of edible films and coatings. Chitosan has antibacterial and antifungal properties which qualify it for food protection, however, its weak mechanical properties, gas and water vapor permeability limit its uses. This review discusses the application of chitosan and its blends with other natural polymers such as starch and other ingredients for example essential oils, and clay in the field of edible films for food protection. The mechanical behavior and the gas and water vapor permeability of the films are also discussed. References dealing with the antimicrobial behavior of these films and their impact on food protection are explored.     

Updating outdated predictive accident models

Reliable predictive accident models (PAMs) (also referred to as safety performance functions (SPFs)) are essential to design and maintain safe road networks however, ongoing changes in road and vehicle design coupled with road safety initiatives, mean that these models can quickly become dated. Unfortunately, because the fitting of sophisticated PAMs including a wide range of explanatory variables is not a trivial task, available models tend to be based on data collected many years ago and seem unlikely to give reliable estimates of current accidents. Large, expensive studies to produce new models are likely to be, at best, only a temporary solution. This paper thus seeks to develop a practical and efficient methodology to allow currently available PAMs to be updated to give unbiased estimates of accident frequencies at any point in time. Two principal issues are examined: the extent to which the temporal transferability of predictive accident models varies with model complexity; and the practicality and efficiency of two alternative updating strategies. The models used to illustrate these issues are the suites of models developed for rural dual and single carriageway roads in the UK. These are widely used in several software packages in spite of being based on data collected during the 1980s and early 1990s. It was found that increased model complexity by no means ensures better temporal transferability and that calibration of the models using a scale factor can be a practical alternative to fitting new models.     

Comparative lyophilized platelet-rich plasma wafer and powder for wound-healing enhancement: formulation,in vitro and in vivo studies

Platelet-rich plasma (PRP) accelerates wound healing, as it is an excellent source of growth factors. PRP was separated from whole human blood by centrifugation. PRP powder and wafers were prepared by lyophilization, with the wafers prepared using sodium carboxymethylcellulose (Na CMC). The PRP wafers showed porous structures, as indicated by scanning electron microscopy (SEM) images, and the ability of the wafer to absorb exudates and thus promote wound healing was tested with the hydration capacity test. The platelet count was tested and indicated that the presence of PRP in the wafers had no effect on the platelet count. An antimicrobial activity test was carried out, showing that PRP had antibacterial activity against Gram-negative bacteria. Compared with lyophilized PRP powder and PRP-free wafers, PRP wafers showed the highest percent of wound size reduction on induced wounds in rats. Histopathological examination of rat skin showed that the PRP wafers achieved the shortest healing time, followed by the lyophilized PRP powder and finally the PRP-free wafers. The present study revealed that PRP can be formulated as a wafer, which is a promising pharmaceutical delivery system that can be used for enhanced wound-healing activity and improved the ease of application compared to lyophilized PRP powder.     

Unbiased high-throughput screening of reactive metabolites on the linear ion trap mass spectrometer using polarity switch and mass tag triggered data-dependent acquisition

Constant neutral loss (CNL) and precursor ion (PI) scan have been widely used for the in vitro screening of glutathione conjugates derived from reactive metabolites, but these two methods are only applicable to triple quadrupole or hybrid triple quadrupole mass spectrometers. Additionally, the success of CNL and PI scanning largely depends on structure and CID fragmentation pathways of GSH conjugates. In the present study, a highly efficient methodology has been developed as an alternative approach for high-throughput screening and structural characterization of reactive metabolites using the linear ion trap mass spectrometer. In microsomal incubations, a mixture of glutathione [GSH, gamma-glutamyl-cystein-glycin] and the stable-isotope labeled compound [GSX, gamma-glutamyl-cystein-glycin-(13)C2-(15)N] was used to trap reactive metabolites, resulting in formation of both labeled and unlabeled conjugates at a given isotopic ratio. A mass difference of 3.0 Da between the natural and labeled GSH conjugate (mass tag) at a fixed isotopic ratio constitutes a unique mass pattern that can selectively trigger the data-dependent MS(2) scan of both isotopic partner ions, respectively. In order to eliminate the response bias of GSH adducts in the positive and negative mode, a polarity switch is executed between the mass tag-triggered data dependent MS(2) scan, and thus ESI- and ESI+ MS(2) spectra of both labeled and nonlabeled GSH conjugates are obtained in a single LC-MS run. Unambiguous identification of glutathione adducts was readily achieved with great confidence by MS(2) spectra of both labeled and unlabeled conjugates. Reliability of this method was vigorously validated using several model compounds that are known to form reactive metabolites. This approach is not based on the appearance of a particular product ion such as MH(+) - 129 and anion at m/z 272, whose formation can be structure-dependent and sensitive to the collision energy level; therefore, the present method can be suitable for unbiased screening of any reactive metabolites, regardless of their CID fragmentation pathways. Additionally, this methodology can potentially be applied to triple quadrupole or hybrid triple quadrupole mass spectrometers.