Mitigation approaches and techniques for combustion power plants flue gas emissions: A comprehensive review.

Population growth and urbanization are driving energy demand. Despite the development of renewable energy technologies, most of this demand is still met by fossil fuels. Flue gases are the main air pollutants from combustion power plants. These pollutants include particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), and carbon oxides (COx). The release of these pollutants has adverse effects on human health and the environment, including serious damage to the human respiratory system, acid rain, climate change, and global warming. In this review, a wide range of conventional and new technologies that have the potential to be used in the combustion power plant sector to manage and reduce flue gas pollutants have been examined. Nowadays, conventional approaches to emissions control and management, which focus primarily on post-combustion techniques, face several challenges despite their widespread use and commendable effectiveness. Therefore, studies that have proposed alternative approaches to achieve improved and more efficient methods are reviewed. The results show that new advances such as novel PM collectors, attaining an efficiency of nearly 100 % for submicron particles, microwave systems, boasting an efficiency of nearly 90 % for NO and over 95 % for SO2, electrochemical systems achieving above 90 % efficiency for NOx reduction, non-thermal plasma processes demonstrating an efficiency close to 90 % for NOx, microalgae-based methods with efficiency ranging from 80 % to 99 % for CO2, and wet scrubbing, exhibit considerable potential in addressing the shortcomings of conventional systems. Furthermore, the integration of hybrid methods, particularly in regions prioritizing environmental concerns over economic considerations, holds promise for enhanced control and removal of flue gas pollutants with superior efficiency.

Dynamic analysis of a micro-cantilever beam in non-contact mode: Classic and Strain Gradient theories.

This article investigates the dynamic behavior of the micro-cantilever beam in a non-contact atomic force microscope based on classic and Strain Gradient continuum theories. Governing equation of the system is derived using Euler-Bernoulli and Strain Gradient theories as a nonlinear partial differential equation. Then, the equation is converted to a nonlinear ordinary differential equation using the Galerkin method, and the lumped model is derived. The effect of van der Waals repulsive term is investigated, and it is demonstrated that its repulsive term has no considerable effect on the dynamic of the system compared with its attractive term. The stability region of the system and the frequency response are computed and validated analytically and numerically. The obtained analytical equation is used for comparing the frequency response of the classic and Strain Gradient systems. It was observed that the classic theory predicts the nonlinear behavior of the system including softening for a specific dimension, while the dynamic behavior of the system is linear for the same dimensions from the Strain Gradient theory point of view. This difference probably roots in ignoring the size effect in submicron scales by the classic theory. HIGHLIGHTS: The influence of the repulsive term of van der Waals force on the dynamic behavior of micro-beam and this term is investigated. A general closed-form equation is derived for the stability region of AFM by an analytical approach. Effect of size on the stability region is investigated. The frequency response of the system is derived using the multiscale method (MSM) approach.

Functional conductive nanomaterials via polymerisation in nano-channels: PEDOT in a MOF.

Reactions inside the pores of metal-organic frameworks (MOFs) offer potential for controlling polymer structures with regularity to sub-nanometre scales. We report a wet-chemistry route to poly-3,4-ethylenedioxythiophene (PEDOT)-MOF composites. After a two-step removal of the MOF template we obtain unique and stable macroscale structures of this conductive polymer with some nanoscale regularity.

Electroactive polymers for sensing.

Electromechanical coupling in electroactive polymers (EAPs) has been widely applied for actuation and is also being increasingly investigated for sensing chemical and mechanical stimuli. EAPs are a unique class of materials, with low-moduli high-strain capabilities and the ability to conform to surfaces of different shapes. These features make them attractive for applications such as wearable sensors and interfacing with soft tissues. Here, we review the major types of EAPs and their sensing mechanisms. These are divided into two classes depending on the main type of charge carrier: ionic EAPs (such as conducting polymers and ionic polymer-metal composites) and electronic EAPs (such as dielectric elastomers, liquid-crystal polymers and piezoelectric polymers). This review is intended to serve as an introduction to the mechanisms of these materials and as a first step in material selection for both researchers and designers of flexible/bendable devices, biocompatible sensors or even robotic tactile sensing units.