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Here the problem of designing two degrees of freedom controllers for an unknown plant based on input–output measurements is discussed. Virtual reference feedback tuning aims at minimizing a cost function of the L2-norm type by using a set of data, as no identification process is needed. When constructing this cost function, two model-matching problems are considered between closed loop transfer function and sensitivity function simultaneously. In model-matching procedures, we design virtual input and virtual disturb respectively. Further two filters used to reprocess the input–output measurements are derived to prove the equivalence between virtual reference feedback tuning and model reference control. After constructing one identification cost without any knowledge of the plant, we derive one bound on the difference between the expected identification cost and its sample identification cost under the condition that the number of data points is finite. Further the correlation property between the input and external noise is considered in deriving this bound. Then we continue to derive one probabilistic bound to quantify this difference through using some probability inequalities and knowledge of control theory. The number of data points is obtained by using generalization of independent block sequence. Finally two simulation examples have been performed to demonstrate the effectiveness of the theories proposed in this paper. • Virtual reference feedback tuning control is proposed to design two parameterized controllers. • Virtual input and virtual disturbance are constructed to obtain an optimization problem. • One probability bound is derived to quantify the model quality with finite datapoints. [ABSTRACT FROM AUTHOR]

One of the most common environmental impacts of road transportation is the traffic noise. Linked to this, Start/Stop is a technology which has demonstrated to save fuel by powering off the engine when the vehicle is stopped, such as in front of a traffic light, and restarting the engine instantly when the driver pushes back the pedal brake to proceed. The technology helps also to reduce the CO 2 emission, playing a key role in a way to accomplish stringent emission norms for vehicle manufacturer. However, we are not sure whether it reduces the noise emission and how much? Thus, the main aim of this work is to assess the engine noise emissions of a vehicle incorporating a Start/Stop system in urban traffic, and compare it with those radiated by the mean traffic stream. Experimental results demonstrate that there are no contributions of the Start/Stop system to reduce meaningfully the engine noise in urban traffic. The theoretical model is included to estimate the noise contribution in far field, as a part of a methodology of acoustics measurements for automotive vehicles. [ABSTRACT FROM AUTHOR]

When the sensory–motor integration system is malfunctioning provokes a wide variety of neurological disorders, which in many cases cannot be treated with conventional medication, or via existing therapeutic technology. A brain–computer interface (BCI) is a tool that permits to reintegrate the sensory–motor loop, accessing directly to brain information. A potential, promising and quite investigated application of BCI has been in the motor rehabilitation field. It is well-known that motor deficits are the major disability wherewith the worldwide population lives. Therefore, this paper aims to specify the foundation of motor rehabilitation BCIs, as well as to review the recent research conducted so far (specifically, from 2007 to date), in order to evaluate the suitability and reliability of this technology. Although BCI for post-stroke rehabilitation is still in its infancy, the tendency is towards the development of implantable devices that encompass a BCI module plus a stimulation system. [ABSTRACT FROM AUTHOR]

This manuscript focuses on the implementation of the hierarchical complexity of space-time deterministic and stochastic dynamical systems to study the pollution dispersion behavior. Considering the concurrent environmental scope and requisites to understand the evolution of various types of environmentally related pollutants of high concern, herein, several suitable mathematical models are anticipated. Aiming to study the current pollution phenomenon at hand, we employed a lumped-linear or nonlinear structure and directly discussed in support of relevant equations. Up to some extent, by intuition, the researcher knows which model is more complex (suitable) than others, so the basic concepts are coated with linked references. Hence, the structural complexity features of the dynamical system are discussed in detail. The continuous dynamical system is discretized, and from the associated time series, a complexity measure can be obtained. There also exists a research gap on complexity theory, which generally deals with the behavior (solutions to the representing differential equations) in a system. Taking all these into account to cover the left behind literature gaps, herein, we propose to glimpse a family of classical models used to describe pollution and bacterial dispersion in the environment. From this review, we offer a qualitative complexity measure to each modeling paradigm by taking into account the underlying space of definition of the model and the key issue of the related differentiability. For instance, a lumped-linear set of differential equations is relatively simple with respect to its nonlinear counterpart because the former lives in the three-dimensional (3-D) real space R3, where the notion of differentiability shows up naturally. However, the latter needs to translate such conception to a manifold by means of differential geometry. Going further, we reflected on this issue for random systems where the notion of differentiability is transformed into an integral equivalence by means of Ito's lemma and so on for more exotic modeling perspectives. Moreover, the study presents a qualitative measure of complexity in terms of underlying sets and feasibility of differentiability. Unlabelled Image • Evolution of pollutants via space-time deterministic and dynamical systems • A qualitative complexity measure for each modeling paradigm is discussed. • Issues and feasibility of differentiability are presented with suitable examples. • Qualitative measures are given in terms of underlying sets and feasibility. [ABSTRACT FROM AUTHOR]

Supercritical-CO 2 fluid extraction (SFE) is a green technology which is being used for the extraction of bioactive compounds such as pigments and fatty acids, in recent years. Naturally occurring plants or plant-based extracts are considered potential candidates with antioxidant and antimicrobial activities. Therefore, in this work, a range of locally available natural plants i.e. oregano, Mexican arnica also known as Heterotheca inuloides , lemon peel, and blackberry marc was analyzed for the extraction of high-value compounds. A multivariable linear regression model was used to analyze the output variables in relation with the inputs i.e. pressure (P), temperature (T), and co-solvent (CoS). Based on Arrhenius equation, the linear correlativity of the data with an activation energy Ea = 6064.14 kJ/mol and a pre-exponential factor of k 0 = 0.388 s −1 were recorded. The thermodynamic parameters of enthalpy, entropy, and Gibbs free energy were also evaluated, correlating the thermodynamics with the extraction yield of the process. [ABSTRACT FROM AUTHOR]

The presence of endocrine-disrupting chemicals (EDCs) in water resources has significant negative implications for the environment. Traditional technologies implemented for water treatment are not completely efficient for removing EDCs from water. Therefore, research on sustainable remediation has been mainly directed to novel decontamination approaches including nano-remediation. This emerging technology employs engineered nanomaterials to clean up the environment quickly, efficiently, and sustainably. Thus, nanomaterials have contributed to a wide variety of remediation techniques like adsorption, filtration, coagulation/flocculation, and so on. Among the vast diversity of decontamination technologies catalytic advanced oxidation processes (AOPs) outstand as simple, clean, and efficient alternatives. A vast diversity of catalysts has been developed demonstrating high efficiencies; however, the search for novel catalysts with enhanced performances continues. In this regard, nanomaterials used as nanocatalysts are exhibiting enhanced performances on AOPs due to their special nanostructures and larger specific surface areas. Therefore, in this review we summarize, compare, and discuss the recent advances on nanocatalysts, catalysts doped with metal-based nanomaterials, and catalysts doped with carbon-based nanomaterials on the degradation of EDCs. Finally, further research opportunities are identified and discussed to achieve the real application of nanomaterials to efficiently degrade EDCs from water resources. [Display omitted] • Pollution is a critical issue that requires joint efforts to green the environment. • The trends in carbon-based nanomaterials for bioremediation are scrutinized. • Sustainable mitigation strategies for highly hazardous toxins are given. [ABSTRACT FROM AUTHOR]

Coffee is one of the most important commercial traded commodities in the international market, as well as the most popular beverage around the world. In Mexico, organic coffee cultivation (specifically, Arabica coffee crops) is a highly demanded that generates up to 500,000 employments in 14 federal entities. Among various coffee producers, Chiapas, Veracruz, and Oaxaca are responsible of 80% of the total coffee production in the country. Currently, Mexico is the leading producer of organic coffee in the world. However, there have been a slow recovery due to the large production losses since 2012, caused by earlier and highly aggressive outbreaks of coffee leaf rust (CLR), in the country, where the infectious agent is known as Hemileia vastatrix (HV). This phenomenon is becoming frequent, and climate change effects could be the main contributors. This spontaneous proliferation was generated in Mexico, due to the precipitation and temperature variability, during the last decade. As result, in Mexico, the biological interaction between coffee crops and their environment has been harmed and crucial characteristics, as crop yield and quality, are particularly being affected, directly by the negative effects of the greenhouse phenomenon, and indirectly, through diseases as CLR. Therefore, this review discusses the contribution of climate change effects in the early development of CLR in Mexico. The focus is also given on possible schemes and actions taken around the world as control measures to adapt the vulnerable coffee varieties to tackle this challenging issue. Unlabelled Image • Mexico is the leading producer worldwide regarding organic coffee. • Climate change has a strong relationship with the early development of Hemileia vastatrix. • The variabilities generated in the rainfall and temperature patterns are presented. • More technological strategies and breeding programs must be implemented. [ABSTRACT FROM AUTHOR]