Federal University of Maranhão

We study the behavior of holomorphic nets on Carleson sets of uniqueness. In particular, we prove that if a holomorphic net is zero, in the sense of Colombeau Generalized Functions, on a Carleson set of uniqueness, then it is zero and converges uniformly to the zero function on compact subset. In case f is a classical holomorphic function, we completely describe its set of zeros in the ring of Colombeau Generalized complex numbers C‾.

This paper presents a mixed-integer linear programming (MILP) model for optimizing surplus hydropower sales in Brazil's Free Contracting Market (ACL) under operational constraints and market volatility. The proposed framework integrates (i) dynamic liquidity constraints calibrated from historical trading activity, (ii) multi-horizon energy contracts (daily, monthly, quarterly, and semiannual), and (iii) risk management through Conditional Value at Risk (CVaR). Unlike related portfolio and contract-optimization models that typically neglect execution limits or adopt static volume caps, our formulation embeds time-and product-dependent liquidity envelopes and minimum-lot constraints in a single MILP with CVaR-based risk control. Computational experiments using 2000 price scenarios quantify the trade-off between expected revenue and tail-risk mitigation across different values of the risk-aversion parameter lambda.

Accurate species identification is a challenge in megadiverse regions, where morphology alone can lead to overestimation or underestimation of biodiversity. In this context, the incorporation of molecular approaches, such as DNA barcoding, has been useful in accurately estimating regional biodiversity, revealing cryptic diversity, and enabling identification by non-specialists. This study generated a molecular database of fishes for Parque Nacional dos Lençóis Maranhenses and adjacent areas, based on sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Haplotype analyses were conducted using Maximum likelihood (ML), and the delimitation of Operational Taxonomic Units (OTUs) combined the following methods: Kimura 2-parameter model (K2P), Assemble Species by Automatic Partitioning (ASAP) and Poisson Tree Processes (PTP) methods, using K2P ≥ 2

The presence of polluting gases can generate problems in various sectors, whether in the environment due to their presence as air pollutants or in motor vehicles that use natural gas as a fuel, since natural gas contains a small amount of pollutants that are sufficient to impair combustion and accelerate engine degradation. Methods for capturing pollutants or purifying a gas of interest using porous materials are already being evaluated, and in this context, MOFs emerge as a promising material for this application. Changes in the organic unit can promote increased adsorption of a gas of interest, making the structure promising for a specific application. So, this work sought to evaluate the ability of IRMOF-2 to purify natural gas (methane) using IRMOF-2 series. The study was conducted using computational simulations with DFT, semiempirical methods, and GCMC. The model was validated by comparing it with experimental adsorption values already published in the literature. Based on the results, it was possible to verify that H2S interacts strongly with all adsorption sites of the IRMOF-2 series, which allows it to win the competition with other gases and interact more efficiently even in mixtures containing CH4, N2, and CO2, resulting in more effective capture, which can be maximized by increasing the pressure and reducing the temperature. Thus, if the objective is methane purification via H2S capture, the IRMOF-2 series emerges as a promising group of structures, with IRMOF-2-F standing out the most among them.

This work proposes an event-triggered adaptive sliding mode control strategy for nonlinear systems subject to time-varying delays, modeled by interval type-2 Takagi–Sugeno fuzzy systems with distinct matrices for each linear subsystem. A non-overestimating adaptation law is introduced to handle matched disturbances with unknown upper bounds, guaranteeing gain convergence once the state trajectory enters a positively invariant practical sliding mode region. The reaching in finite time, the practical sliding mode region, and the practical stability region are all established via upper bounds that do not require any prior knowledge regarding the bound of the disturbance. Delay-dependent sufficient conditions for practical stability under practical sliding mode are derived via a Lyapunov–Krasovskii functional, with explicit dependence on both the delay and the variation rate upper bound of the delay, certifying the uniformly ultimately bounded property of the closed-loop system. The event-triggering mechanism is proven to be Zeno-free. Numerical simulations across three case studies demonstrate the robustness and effectiveness of the proposed strategy, while preserving the practical sliding mode under the most stringent delay conditions.