On-off scheduling schemes for power-constrained electric vehicle charging

In this paper, we study the problem of establishing a dynamic charging schedule of electric vehicles (EVs) at a charging station, assuming that limited power implies that only a limited number of EVs can charge simultaneously. The only control we assume to be available to the charging station is the ability to (at any given time) turn on or off the power supply to any EV, with this tool we want to develop a charging schedule that will satisfy the energy demands of the EVs in their intended deadlines. We propose two distinct approaches to this problem: a discretized time version, based on a greedy-like algorithm, and a continuous time version, based on linear programming. We compare these two approaches and numerically study the improvement they yield in the efficiency of the charging procedure, when applied to simulated data based on real parking data. Finally, we illustrate the flexibility of the models by sketching several possible extensions.     

Cleansing contaminated seawaters using marine cyanobacteria: evaluation of trace metal removal from the medium

The use of microbial biomass in biosorption is already being studied as a potential alternative to (or combined with) conventional processes, where several algae and microorganisms have already shown promising ability to uptake metals. Cyanobacteria (blue-green algae) are widespread organisms, with specific properties, such as high nutrient removal capacity and tolerance to highly variable conditions which make them well-suited for wastewater and remediation purposes. The main aim of this work was to evaluate the use of a marine cyanobacterium LEANCYA 21 (Synechocystis sp.), collected from the Portuguese southern border, for the removal of selected trace metals when in natural seawater culture medium. It was observed, for the first time, that this particular strain is capable of uptaking Pb, Ni and Zn (at nM levels) from seawater solutions using small amounts of biomass. Uptake values for Pb were up to 90% (0.75 mg g^?1 biomass) in 6 h. The specific biosorption curves of Ni and Zn showed that these metals follow a first order kinetics biosorption in batch conditions. Solutions containing multimetals have revealed that Ni uptake is affected by the presence of Pb and Zn. The calculated specific absorption values were high enough to predict a possible application in aquaculture where such low levels of metals may inhibit microalgae growth.     

A Hybrid Ring‐Opening Metathesis Polymerization Catalyst Based on an Engineered Variant of the β‐Barrel Protein FhuA

A β‐barrel protein hybrid catalyst was prepared by covalently anchoring a Grubbs–Hoveyda type olefin metathesis catalyst at a single accessible cysteine amino acid in the barrel interior of a variant of β‐barrel transmembrane protein ferric hydroxamate uptake protein component A (FhuA). Activity of this hybrid catalyst type was demonstrated by ring‐opening metathesis polymerization of a 7‐oxanorbornene derivative in aqueous solution.     

Multifunctional natural fibers: the potential of core shell MgO–SiO2 nanoparticles

Cellulose - Core–shell nanoparticles (NPs) based on metal oxides, namely magnesium oxide (MgO) and silica (SiO2), are a fantastic alternative for natural fibers’ functionalization. In...     

Spatial updating, spatial transients, and regularities of a complex automaton with nonperiodic architecture

We study the dynamics of patterns exhibited by rule 52, a totalistic cellular automaton displaying intricate behaviors and wide regions of active/inactive synchronization patches. Systematic computer simulations involving 2(30) initial configurations reveal that all complexity in this automaton originates from random juxtaposition of a very small number of interfaces delimiting active/inactive patches. Such interfaces are studied with a sidewise spatial updating algorithm. This novel tool allows us to prove that the interfaces found empirically are the only interfaces possible for these periods, independently of the size of the automata. The spatial updating algorithm provides an alternative way to determine the dynamics of automata of arbitrary size, a way of taking into account the complexity of the connections in the lattice.     

Surface Roughness Characterization of Poly(methylmethacrylate) Films with Immobilized Eu(III) β-Diketonates by Fractal Analysis

The structural complexity of the 3-D surface of poly(methylmethacrylate) films with immobilized europium β-diketonates was studied by atomic force microscopy and fractal analysis. Fractal analysis of surface roughness revealed that the 3-D surface has fractal geometry at the nanometer scale. Poly(methylmethacrylate) (PMMA) as immobilization matrix is dense and uniform, and a tendency for formation of chain structures was observed. Fractal analysis can quantify key elements of 3-D surface roughness such as the fractal dimensions D _f determined by the morphological envelopes method of the Eu(DBM)₃ and Eu(DBM)₃ · dpp nanostructures, which are not taken into account by traditional surface statistical parameters.     

Kinetics and Mechanism of Mineral Respiration: How Iron Hemes Synchronize Electron Transfer Rates

Anaerobic microorganisms of the Geobacter genus are effective electron sources for the synthesis of nanoparticles, for bioremediation of polluted water, and for the production of electricity in fuel cells. In multistep reactions, electrons are transferred via iron/heme cofactors of c‐type cytochromes from the inner cell membrane to extracellular metal ions, which are bound to outer membrane cytochromes. We measured electron production and electron flux rates to 5×10⁵ e s^?1 per G. sulfurreducens. Remarkably, these rates are independent of the oxidants, and follow zero order kinetics. It turned out that the microorganisms regulate electron flux rates by increasing their Fe²⁺/Fe³⁺ ratios in the multiheme cytochromes whenever the activity of the extracellular metal oxidants is diminished. By this mechanism the respiration remains constant even when oxidizing conditions are changing. This homeostasis is a vital condition for living systems, and makes G. sulfurreducens a versatile electron source.     

Mechanical Behavior of Polymer Gels for RDCs and RCSAs Collection: NMR Imaging Study of Buckling Phenomena

Anisotropic NMR parameters, such as residual dipolar couplings (RDCs), residual chemical shift anisotropies (RCSAs) and residual quadrupolar couplings (RQCs or Δν_Q), appear in solution‐state NMR when the molecules under study are subjected to a degree of order. The tunable alignment by reversible compression/relaxation of gels (PMMA and p‐HEMA) is an easy, user‐friendly, and very affordable method to measure them. When using this method, a fraction of isotropic NMR signals is observed in the NMR spectra, even at a maximum degree of compression. To explain the origin of these isotropic signals we decided to investigate their physical location inside the NMR tube using deuterium 1D imaging and MRI micro‐imaging experiments. It was observed that after a certain degree of compression the gels start to buckle and they generate pockets of isotropic solvent, which are never eliminated. The amount of buckling depends on the amount of cross‐linker and the length of the gel.     

A data-driven,high-throughput methodology to determine tissue-specific differentially methylated regions able to discriminate body fluids

Tissue-specific differentially methylated regions (tDMRs) are regions of the genome with methylation patterns that modulate gene expression in those tissue types. The detection of tDMRs in forensic evidence can permit the identification of body fluids at trace levels. In this report, we have performed a bioinformatic analysis of an existing array dataset to determine if new tDMRs could be identified for use in body fluid identification from forensic evidence. Once these sites were identified, primers were designed and bisulfite modification was performed. The relative methylation level for each body fluid at a given locus was then determined using qPCR with high-resolution melt analysis (HRM). After screening 127 tDMR's in multiple body fluids, we were able to identify four new markers able to discriminate blood (2 markers), vaginal epithelia (1 marker) and buccal cells (1 marker). One marker for each target body fluid was also tested with pyrosequencing showing results consistent with those obtained by HRM. This work successfully demonstrates the ability of in silico analysis to develop a novel set of tDMRs capable of being differentiated by real time PCR/HRM. The method can rapidly determine the body fluids left at crime scenes, assisting the triers of fact in forensic casework.     

Electrochemical studies and square wave adsorptive stripping voltammetry of the antidepressant fluoxetine

The electrochemical reduction of the antidepressant drug fluoxetine was investigated by cyclic, linear sweep, differential pulse and square wave voltammetry using a hanging mercury drop electrode in alkaline buffer solution in water and in a water/acetonitrile mixed solvent. Cyclic voltammograms in aqueous solution showed very strong adsorption of fluoxetine on the electrode with formation of a compact film. The effect of addition of different percentages of acetonitrile on the voltammetric response was evaluated. It is shown that acetonitrile protects the electrode surface, thus preventing the adsorption of fluoxetine as a compact film, although reduction occurs at more negative potentials. Adsorption was used to accumulate the drug onto the electrode surface. The adsorbed species were measured voltammetrically by reduction at -1.3 V in an aqueous 0.05 M Ringer buffer, pH 12, 20% acetonitrile v/v. Linear calibration graphs were obtained in the range 0.52-5.2 M. The quantification of fluoxetine in pharmacological formulations existing in the market was performed using adsorptive square wave cathodic stripping voltammetry. and compared with data from UV spectrophotometry. The method is simple and not time-consuming. A comparative high performance liquid chromatography assay with UV detection was performed. Recovery data for both methods are reported.