Abstract
To alleviate the greenhouse gas emissions by the chemical industry, electrification has been proposed as a solution where electricity from renewable sources is used to power processes. The ...adoption of renewable energy is complicated by its spatial and temporal variations. To address this challenge, we investigate the potential of distributed manufacturing for electrified chemical processes installed in a microgrid. We propose a multiscale mixed‐integer linear programming model for locating modular electrified plants, renewable‐based generating units, and power lines in a microgrid that includes monthly transportation and hourly scheduling decisions. We propose a K‐means clustering‐based aggregation disaggregation matheuristic to solve the model efficiently. The model and algorithm are tested using a case study with 20 candidate locations in Western Texas. Additionally, we define a new concept, “the Value of the Multi‐scale Model,” to demonstrate the additional economic benefits of our model compared with a single‐scale model.
We propose an approach to solving the AC network-constrained unit commitment problem (AC-NCUC) of large-scale power systems. This approach relies on solving convex (continuous and mixed-integer) ...optimization problems. First, we formulate a second-order conic relaxation of the original optimization problem, which renders a mixed-integer second-order conic optimization problem. To solve this problem, we use Benders' decomposition, which decomposes it into a master problem, which is mixed-integer linear, and a subproblem, which is continuous and second-order conic. To improve the convergence of the Benders' algorithm, we add several linear feasibility constraints to the master problem. Since the second-order relaxation of the original problem cannot guarantee AC feasibility of the solution found, we ensure such feasibility by solving a sequence of continuous convex optimization problems. We numerically validate the proposed approach using a Texas 2000-bus system.
Turmeric or Curcuma is a natural product that has anti-inflammatory, antioxidant and anti-apoptotic pharmacological properties. It can be used in the control of the aging process that involves ...oxidative stress, inflammation, and apoptosis. Aging is a physiological process that affects higher cortical and cognitive functions with a reduction in learning and memory, limited judgment and deficits in emotional control and social behavior. Moreover, aging is a major risk factor for the appearance of several disorders such as cerebrovascular disease, diabetes mellitus, and hypertension. At the brain level, the aging process alters the synaptic intercommunication by a reduction in the dendritic arbor as well as the number of the dendritic spine in the pyramidal neurons of the prefrontal cortex, hippocampus and basolateral amygdala, consequently reducing the size of these regions. The present review discusses the synaptic changes caused by the aging process and the neuroprotective role the Curcuma has through its anti-inflammatory, antioxidant and anti-apoptotic actions.
We address the daily scheduling of generating units (unit commitment) in a system whose production mix includes a large number of natural-gas-fired units. We assume that the natural-gas system, ...operating under market conditions, does its best to supply the natural-gas for electricity production required by the power system. We formulate this problem as a bi-level model whose upper-level problem represents the scheduling of generating units under a second-order conic relaxation of the AC network constraints, and whose lower-level one represents the clearing of the natural-gas market. The upper-level problem is mixed-integer second-order conic, while the lower-level one is second-order conic as well, but continuous. We replace the lower-level problem by its optimality conditions in the form of primal constraints, dual constraints, and strong duality equality, which results in a single-level nonconvex mixed-integer nonlinear optimization problem. To improve the computational tractability of such formulation, we derive a mixed-integer second-order conic relaxation of the single-level nonconvex mixed-integer nonlinear optimization problem. Such problem is solved using a Benders-type outer-approximation decomposition framework with a master mixed-integer linear problem and two subproblems that are nonlinear but convex. The communication between the master problem and the subproblems is enhanced by incorporating into the master problem linearized information pertaining to the subproblems and valid linear inequalities. The benefits of the proposed model and the effectiveness of the solution procedure are illustrated using the IEEE 24-bus test system coupled with a 20-node natural-gas system and the Central Illinois 200-bus power system coupled with a 48-node natural-gas system.
De cara a aumentar e impulsar la presencia de las metodologías activas en la enseñanza de la Educación Física, en este artículo se describen las características básicas de una experiencia gamificada ...denominada “Súper Mario Bros”, que ha sido desarrollada y aplicada durante el curso 2017/2018 en una de las asignaturas del Grado de Ciencias de la Actividad Física y del Deporte (CAFE). Además de detallar los “ingredientes clave” de los que se compone la gamificación, y la manera en la que el docente los incorpora en su experiencia, aquí se presentan un conjunto de reflexiones sobre diversos aspectos a tener en cuenta en cada uno de dichos ingredientes. En definitiva, con este trabajo se quiere difundir la manera en la que se puede gamificar una asignatura, a partir de una experiencia real y exitosa, que puede servir como modelo inspirador para el profesorado interesado.
•Propose a model to quantitatively assess the consequences of data-integrity cyber attacks in the operation of power systems.•Based on AC models of state estimation and optimal power flow.•The ...proposed model considers a resource-constrained omniscient attacker.•The attacker pursues to stage an attack while remaining unobservable to the bad data detection algorithm.•Demonstrate the effectiveness of the proposed model using a 6-bus system a and the IEEE 30-bus test system.
We propose in this paper a model to quantify the consequences of the vulnerabilities of the AC-based state estimation against data-integrity cyber attacks. We consider attacks whose goals are to corrupt the state estimator and/or the operation of the power grid. By considering AC-based models of the state estimator and the operation of the power system, the proposed model allows quantifying the reliability consequences (i.e., alteration in the active and reactive power), and the economic consequences (e.g., distorting locational marginal prices) of such attacks. We consider a resource-constrained omniscient attacker intending to alter the operation of the power system. We impose a stealthy condition on the attacker so that its malicious action is invisible to the bad-data-detection algorithm. The upper-level problem of the proposed bilevel model represents the attacker’s action and pursues disrupting the system operation and it is constrained by two lower-level problems. The first lower-level problem is the state-estimation that calculates the most likely state of the system considering the corrupted measurement. The second lower-level problem is a conic relaxation of the optimal power flow that uses the output of the state estimation problem to minimize operation costs. We illustrate the proposed bilevel model using two test systems.
This paper investigates the effect of uncertainty in the allocation of photovoltaic (PV) generation, solar irradiance, and its impact on the power flow in a distribution network. The solar irradiance ...available in the National Renewable Energy Laboratory Resource Data Center is clustered into two states: high and low irradiance defined by a threshold. The uncertainty is modeled based on Non-Gaussian distribution, obtained using kernel density estimation. This estimation aids in achieving the probability density function and cumulative distribution functions of the solar irradiance. Moreover, the load demand, wind speed, and generator location are modeled according to Gaussian, Weibull, and discrete uniform distribution functions, respectively. As a part of probabilistic power flow, the backward/forward sweep method is used to solve each scenario of the Monte Carlo simulation. The proposed framework is applied to the 33-node test system considering three different test cases. The first case considers deployment of PV systems in three microgrids of the electric grid, and the other two test cases analyze different levels of penetration of randomly allocated PV and wind power systems. At the end, the results indicate potential reverse power flow through certain branches of the grid, and the renewables have a major impact on the system.
Recent scientific and technological advances have enabled the detection of gravitational waves, autonomous driving, and the proposal of a communications network on the Moon (Lunar Internet or ...LunaNet). These efforts are based on the measurement of minute displacements and their corresponding force transduction, which enables acceleration, velocity, and position determination for navigation. State‐of‐the‐art accelerometers use capacitive or piezoresistive techniques and micro‐electromechanical systems (MEMS) via integrated circuit (IC) technologies to drive transducers and convert their output for electric readout. In recent years, laser optomechanical transduction and readout have enabled highly sensitive detection of motional displacement. Here the theoretical framework is further examined for the novel mechanical frequency readout technique of optomechanical transduction when the sensor is driven into oscillation mode. Theoretical and physical agreements are demonstrated, and the most relevant performance parameters are characterized by a device with a 1.5 mg Hz−1 acceleration sensitivity, a 2.5 fm Hz−1/2 displacement resolution corresponding to a 17.02 µg Hz−1/2 force‐equivalent acceleration, and a 5.91 Hz nW−1 power sensitivity, at the thermodynamical limits. In addition, a novel technique is presented for dynamic range extension while maintaining the precision sensing sensitivity. This inertial accelerometer is integrated on‐chip and enabled for packaging, with a laser‐detuning‐enabled approach.
A parametrically driven optomechanical accelerometer with a 1.5 mg Hz−1 acceleration sensitivity, a 2.5 fm Hz−1/2 displacement resolution corresponding to a 17.02 µg Hz−1/2 force‐equivalent acceleration, and a 5.91 Hz nW−1 power sensitivity is demonstrated. Driven with calibrated pump detuning, the transducer is capable of extending the dynamic range of a single sensor by multiple times, without sacrificing resolution.
Functional foods in pet nutrition: Focus on dogs and cats Di Cerbo, Alessandro; Morales-Medina, Julio Cesar; Palmieri, Beniamino ...
Research in Veterinary Science/Research in veterinary science,
June 2017, 2017-Jun, 2017-06-00, 20170601, Letnik:
112
Journal Article
Recenzirano
Odprti dostop
Functional foods provide health benefits if they are consumed on a regular basis as part of a varied diet. In this review, we discuss the availability and role of functional foods in pet nutrition ...with a focus on dogs and cats. Indeed, functional foods modify gastrointestinal physiology, promote changes in biochemical parameters, improve brain functions and may reduce or minimize the risk of developing specific pathologies. This evidence derives largely from clinical studies while only limited evidence is available from studies in dogs and cats. Therefore, functional food consumption should be further investigated in pet nutrition to understand how dietary interventions can be used for disease prevention and treatment.
•Functional foods provide health benefits when integrated in the diet.•This review shows evidence of use of functional foods in pets.•Functional food can reduce the risk of disease and/or support the body.•Pets are a valuable model to study the role and mechanism of functional foods.
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