Biostimulants are materials that when applied in small amounts are capable of promoting plant growth. Nanoparticles (NPs) and nanomaterials (NMs) can be considered as biostimulants since, in specific ranges of concentration, generally in small levels, they increase plant growth. Pristine NPs and NMs have a high density of surface charges capable of unspecific interactions with the surface charges of the cell walls and membranes of plant cells. In the same way, functionalized NPs and NMs, and the NPs and NMs with a corona formed after the exposition to natural fluids such as water, soil solution, or the interior of organisms, present a high density of surface charges that interact with specific charged groups in cell surfaces. The magnitude of the interaction will depend on the materials adhered to the corona, but high-density charges located in a small volume cause an intense interaction capable of disturbing the density of surface charges of cell walls and membranes. The electrostatic disturbance can have an impact on the electrical potentials of the outer and inner surfaces, as well as on the transmembrane electrical potential, modifying the activity of the integral proteins of the membranes. The extension of the cellular response can range from biostimulation to cell death and will depend on the concentration, size, and the characteristics of the corona.

Agriculture stands to benefit from nanotechnology in areas such as combating pests and pathogens, regulating the growth and quality of crops, and developing intelligent materials and nanosensors. The objective of this paper is to provide an overview of the use of nanomaterials (NMs) and nanoparticles (NPs) in plant nutrition, highlighting their advantages and potential uses, but also reviewing their possible environmental destination and effects on ecosystems and consumers. NPs and NMs have been shown to be an attractive alternative for the manufacture of nanofertilizers (NFs), which are more effective and efficient than traditional fertilizers. Because of their impact on crop nutritional quality and stress tolerance in plants, the application of NFs is increasing. However, there are virtually no studies on the potential environmental impact of NPs and NMs when used in agriculture. These studies are necessary because NPs and NMs can be transferred to ecosystems by various pathways where they can cause toxicity to organisms, affecting the biodiversity and abundance of these ecosystems, and may ultimately even be transferred to consumers.

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This paper proposes a nonlinear synchronization controller for a swarm of unicycle robots performing a cooperative task, i.e., following a desired trajectory per robot while maintaining a prescribed formation. The effect of communication between robots is analyzed and several network topologies are investigated, e.g., all‐to‐all, ring type, undirected, among others. The stability analysis of the closed loop system is provided using the Lyapunov method. Experiments with four unicycle robots are presented to validate the control law and communication analysis. Accumulated errors over the experiment time are presented in order to determine which topology is most efficient.

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This paper is addressed to the problem of designing an adaptive cascade controller to stabilize a jacketed continuous chemical reactor whose isothermal dynamics are globally stable. Assuming that the heat generation and transfer models are uncertain, the controller is built on the basis of back-stepping procedure in conjunction with the mass and energy conservation principles that underlie the reactor behaviour. The corresponding closed-loop dynamics are studied yielding a semiglobal stability criterion coupled with a systematic construction-tuning procedure. The resulting cascade controller has aPI-type structure with an antireset windup scheme, and is put in perspective with its industrial-type counterpart. A simulated example is used to illustrate the functioning of the proposed controller.

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