Sensitive and Reversible Detection of Methanol and Water Vapor by In Situ Electrochemically Grown CuBTC MOFs on Interdigitated Electrodes

The in situ electrochemical growth of Cu benzene‐1,3,5‐tricarboxylate (CuBTC) metal–organic frameworks, as an affinity layer, directly on custom‐fabricated Cu interdigitated electrodes (IDEs) is described, acting as a transducer. Crystalline 5–7 µm thick CuBTC layers are grown on IDEs consisting of 100 electrodes with a width and a gap of both 50 µm and a height of 6–8 µm. These capacitive sensors are exposed to methanol and water vapor at 30 °C. The affinities show to be completely reversible with higher affinity toward water compared to methanol. For exposure to 1000 ppm methanol, a fast response is observed with a capacitance change of 5.57 pF at equilibrium. The capacitance increases in time followed diffusion‐controlled kinetics (k = 2.9 mmol s^?0.5 g^?1_CuBTC). The observed capacitance change with methanol concentration follows a Langmuir adsorption isotherm, with a value for the equilibrium affinity K _e = 174.8 bar^?1. A volume fraction f _MeOH = 0.038 is occupied upon exposure to 1000 ppm of methanol. The thin CuBTC affinity layer on the Cu‐IDEs shows fast, reversible, and sensitive responses to methanol and water vapor, enabling quantitative detection in the range of 100–8000 ppm.     

Role of Insulation Effectiveness on Fire Resistance of Steel Structures under Extreme Loading Events

Fire performance of steel structures is highly dependent on the effectiveness of applied fire insulation. However, insulation materials are susceptible to damage under extreme loading events. A state-of-the-art review on the role of insulation damage on fire resistance of steel structures is presented. Parametric studies on a six-story steel-framed building were carried out to illustrate the effect of insulation damage on fire response of a steel structure. In the analysis, realistic fire scenarios, loading, and failure criteria were taken into consideration. Analysis results indicate that the fire resistance of a steel-framed structure is significantly influenced by the extent of insulation loss, type of fire scenario, and level of lateral load. Insulation damage causes faster deterioration in the structural response of framed buildings under the combined effect of fire and lateral loading. The need for accounting for any insulation damage, arising under extreme loading events, in fire design of steel-framed structures is highlighted, and a performance-based design strategy incorporating fire resistance analysis is discussed.     

Pattern identification in dynamical systems via symbolic time series analysis

This paper presents symbolic time series analysis (STSA) of multi-dimensional measurement data for pattern identification in dynamical systems. The proposed methodology is built upon concepts derived from Information Theory and Automata Theory. The objective is not merely to classify the time series patterns but also to identify the variations therein. To achieve this goal, a symbol alphabet is constructed from raw data through partitioning of the data space. The maximum entropy method of partitioning is extended to multi-dimensional space. The resulting symbol sequences, generated from time series data, are used to model the dynamical information as finite state automata and the patterns are represented by the stationary state probability distributions. A novel procedure for determining the structure of the finite state automata, based on entropy rate, is introduced. The diversity among the observed patterns is quantified by a suitable measure. The efficacy of the STSA technique for pattern identification is demonstrated via laboratory experimentation on nonlinear systems.     

Palmitoylethanolamide: A Natural Compound for Health Management

All nations which have undergone a nutrition transition have experienced increased frequency and falling latency of chronic degenerative diseases, which are largely driven by chronic inflammatory stress. Dietary supplementation is a valid strategy to reduce the risk and severity of such disorders. Palmitoylethanolamide (PEA) is an endocannabinoid-like lipid mediator with extensively documented anti-inflammatory, analgesic, antimicrobial, immunomodulatory and neuroprotective effects. It is well tolerated and devoid of side effects in animals and humans. PEA’s actions on multiple molecular targets while modulating multiple inflammatory mediators provide therapeutic benefits in many applications, including immunity, brain health, allergy, pain modulation, joint health, sleep and recovery. PEA’s poor oral bioavailability, a major obstacle in early research, has been overcome by advanced delivery systems now licensed as food supplements. This review summarizes the functionality of PEA, supporting its use as an important dietary supplement for lifestyle management.     

Exploration of irreversibility and thermal motion of a nanoliquid with the Newton boundary condition by using the Darcy–Forchheimer rule

This study has been conducted to focus on magnetohydrodynamic flow of a nanoliquid through a microchannel in the presence of a magnetic field. In this article, carbon nanotubes suspended in an aqueous medium were our considered fluid, and we focused on both singlewall and multiwall carbon nanotubes. The numerical calculations have been made via the fourth- and fifth-order Runge–Kutta–Fehlberg method. The flow of the nanoliquid in a microchannel with porosity has been scrutinized with the existence of mutual effects, like, the nanoparticle volume fraction, suction or injection, thermal-dependent heat source, convective boundary conditions, Darcy friction factor, and thermal motion of the nanoparticles. The influence of every major parameter on the profile of momentum, temperature, and entropy generation has been displayed graphically, and we discuss their physical aspects. The numerical outcomes demonstrated that the momentum profile augmented with the buoyancy force, angle of inclination, and Darcy number. Thermal energy was enriched with the heat source parameter, Darcy number, and Hartmann number. The irreversibility rate declined with the volume fraction of nanoparticle and radiation parameter, while it increases with the buoyancy force, Eckert parameter, and Darcy friction factor.     

The three-dimensional bioconvective flow of Sisko nanofluid under Robin's conditions

The proposed model investigates three-dimensional bioconvective Sisko nanofluid flow under Robin's conditions. The Sisko nanofluid has versatile implications in drilling fluids, cement slurries, waterborne coatings, and so on. Furthermore, the inclusion of gyrotactic microorganisms prevents the deposition and agglomeration of the nanoparticles in the base fluid. Buongiorno's model is included to explore the behavior of Brownian motion and thermophoretic factors. The energy and mass transmissions along with the gyrotactic microorganism density are illustrated by the partial differential expression system with Robin's conditions. These are further reframed into an ordinary differential equation system with the aid of similarity transformation. The developing model is tackled by using the MAPLE inbuilt package BVP. The nanofluid acts as a good cooling agent for higher values of the thermophoresis parameter. Furthermore, the pseudoplastic nanofluid performs better than the dilatant nanofluid. The developed model is very useful in energy production and engineering products.     

Effect of mixing on the properties of nanocarbon containing Al2O3-C continuous casting refractories

The functional refractories used in steel casting operations are usually made up of alumina-carbon compositions having graphite as the major source of carbon. In recent times, to reduce the carbon content and to enhance the performance by designing microstructure at nano-sized level, several nano carbon sources and organic binders are introduced to traditional carbon-based refractories. The homogenous distribution of nano carbon sources within the refractory composition is important to get the advantages of its use. In the present work, nanocarbon black is used along with graphite in the alumina-carbon system. Three different mixing procedures are followed and how mixing effects the physical and mechanical properties is evaluated. The mixing order with proper nanocarbon distribution throughout the batch composition provided significant improvement in the properties. The microstructural analysis and in situ phase developments in the samples at different temperatures are also studied.     

The analogy of nanoparticle shapes on the theory of convective heat transfer of Au–Fe3O4 Casson hybrid nanofluid

In recent times, Au nanoparticles have been commonly used for delivering the drug especially in the case of hypothermia of tumors, but low absorption of IR light does not solve destruction of tumor cells. However, nanoparticles such as Fe₃O₄ coated with Au could be used to deliver the drug to a specific spot due to applied external magnetic field. Due to these applications, boundary layer approximation is invoked to simplify the mathematical model. This paper presents the nanoparticle shape analysis and heat transfer features of the Au–Fe₃O₄–blood hybrid nanofluid flowing past a stretching surface on a magnetohydrodynamic medium. Numerical solutions of nonlinear differential equations are obtained by RKF-45 method with the help of shooting technique. The behavior of emerging parameters is described graphically for velocity and temperature profiles. It is found that the blade-shaped Au and Fe₃O₄ nanoparticles have better thermal conductance than brick, sphere, cylinder, needle, and platelet shapes. It is also observed that the Lorentz force generated due to magnetic field helps in controlling the flow and enhance the thermal conductivity of hybrid nanofluid.     

Hybrid trefftz plane elasticity elements with p -method capabilities

A family of p-method plane elasticity elements is derived based on the hybrid Trefftz formulation.¹ Exact solutions of the Lamé-Navier equations are used for the intra-element displacement field together with an independent displacement frame function field along the element boundary. The final unknowns are the parameters of the frame function field consisting of the usual degrees of freedom at corner nodes and an optional number of hierarchic degrees of freedom associated with the mid-side nodes. Since the element matrices do not involve integration over the element area, the elements have a polygonal contour with an optional number of curved sides. The quadrilateral element has the same external appearance as the conventional p-method plane elasticity element.^2,3 But unlike in the conventional p-method approach, suitable special-purpose Trefftz functions are generally used to handle the singularity and/or stress concentration problems rather than a local mesh refinement. The practical efficiency of the new elements is assessed through a series of examples.