Flexible operation of large-scale coal-fired power plant integrated with solvent-based post-combustion CO2 capture based on neural network inverse control

Post-combustion carbon capture (PCC) with chemical absorption has strong interactions with coal-fired power plant (CFPP). It is necessary to investigate dynamic characteristics of the integrated CFPP-PCC system to gain knowledge for flexible operation. It has been demonstrated that the integrated system exhibits large time inertial and this will incur additional challenge for controller design. Conventional PID controller cannot effectively control CFPP-PCC process. To overcome these barriers, this paper presents an improved neural network inverse control (NNIC) which can quickly operate the integrated system and handle with large time constant. Neural network (NN) is used to approximate inverse dynamic relationships of integrated CFPP-PCC system. The NN inverse model uses setpoints as model inputs and gets predictions of manipulated variables. The predicted manipulated variables are then introduced as feed-forward signals. In order to eliminate steady-state bias and to operate the integrated CFPP-PCC under different working conditions, improvements have been achieved with the addition of PID compensator. The improved NNIC is evaluated in a large-scale supercritical CFPP-PCC plant which is implemented in gCCS toolkit. Case studies are carried out considering variations in power setpoint and capture level setpoint. Simulation results reveal that proposed NNIC can track setpoints quickly and exhibit satisfactory control performances

Research on the Preparation and Mechanism of the Organic Montmorillonite and Its Application in Drilling Fluid

The study focused on the relation of structure, property, and application of composite prepared by organic cation intercalated montmorillonite (Mt). Herein a new kind of green and steady ionic liquid, 1-hexadecyl-3-methylimidazolium chloride monohydrate (C12mimCl), was chosen as the intercalated agent. This study used molecular dynamics (MD) modeling to examine the interlayer microstructures of montmorillonite intercalated with C12mimCl. The C12mimCl intercalation was relatively fast with a large rate constant. The process was affected by the initial concentration of the solution; the basal spacing increased to 2.08 nm after intercalation. The coordination of electrostatic interaction and hydrogen bonding expelled water molecules out of the clay gallery and bound the layer together, which led to the dehydration of clay. The intercalation of C12minCl into Mt interlayer space affected rheology of the system and improved various properties. This organic clay composite was environmentally friendly and could be used in drilling fluid system. These models provided insights into the prediction of synthesized organic cationic-clay microstructure and guidelines for relevant engineering applications

Smoking and Socio-demographic correlates of BMI

Abstract Background The aim of the current study was to examine the associations between Body Mass Index (BMI) and socio-demographic factors and to examine the relationship between BMI, smoking status and ethnicity. Methods The Singapore Mental Health Study (SMHS) surveyed Singapore Residents (Singapore Citizens and Permanent Residents) aged 18 years old and above. BMI was calculated using height and weight which were self-reported by respondents. Socio-demographic characteristics and smoking status were recorded in a standardized data collection form. Results Six thousand and six hundred sixteen respondents completed the study (response rate of 75.9 %) which constituted a representative sample of the adult resident population in Singapore. Ethnicity, gender and education status were associated with obesity. There was an interaction effect between ethnicity smoking status, and BMI. Indian and Malay smokers were less likely to be obese compared to Chinese smokers. The relationship between ethnicity and BMI was thus reversed when smoking was taken into account. Conclusions The study identified certain subgroups and risk factors that are associated with obesity. There is a need for further research to explore and identify genetic, metabolic and ethnic differences that underlie the interaction between ethnicity and smoking status which affects BMI

Performance of compact plastic scintillator strips with WLS-fiber and PMT/SiPM readout

This work presents the design and performance study of compact strips of plastic scintillator with WLS-fiber readout in a dimension of 0.1 * 0.02 * 2 m3, which evaluates as a candidate for cosmic-ray muon detector for JUNO-TAO. The strips coupling with 3-inch PMTs are measured and compared between the single-end and double-end readout options first, and the strip of double-end option coupling with SiPM is further measured and compared with the results of that with the PMTs. The performance of the strips determined by a detailed survey along their length with cosmic-ray muon after a detailed characterization of the used 3-inch PMTs and SiPMs.The proposed compact strip of plastic scintillator with WLS-fiber coupling with SiPM provides a good choice for cosmic-ray muon veto detector for limited detector dimension in particular

An Efficient Refocusing Scheme for Camera-Array Captured Light Field Video for Improved Visual Immersiveness

Light field video technology attempts to acquire human-like visual data, offering unprecedented immersiveness and a viable path for producing high-quality VR content. Refocusing that is one of the key properties of light field and a must for mixed reality applications has shown to work well for microlens based cameras, but as light field videos acquired by camera arrays have a low angular resolution, the refocused quality suffers. In this paper, we present an approach to improve the visual quality of refocused content captured by a camera array-based setup. Increasing the angular resolution using existing deep learning-based view synthesis method and refocusing the video using shift and sum refocusing algorithm produces over blurring of the in-focus region. Our enhancement method targets these blurry pixels and improves their quality by similarity detection and blending. Experimental results show that the proposed approach achieves better refocusing quality compared to traditional methods

Electrochemical properties of manganese ferrite-based supercapacitors in aqueous electrolyte: the effect of ionic radius

The electrochemical performances of symmetric supercapacitors assembled by MnFeO colloidal nanocrystal clusters (CNCs) in aqueous electrolytes were investigated by using cyclic voltammetry, galvanostatic charge-discharge, cycle stability and electrochemical impedance spectroscopy. Results showed that the capacitance of MnFeO CNCs can be easily adjusted by the controlled electrolytes. It was found that the specific capacitances of CNCs-based electrodes were 97.1, 93.9, 74.2 and 47.4Fg for the electrolytes (2M) containing KOH, NaOH, LiOH and NaSO, respectively, at the current density of 0.1Ag. The capacitance of the electrode was increased from 56.9 to 152.5Fg with aqueous KOH electrolytes changed from 0.5M to 6M. The MnFeO CNCs-based supercapacitor using aqueous KOH (6M) electrolyte displayed the best cycle stability among all the supercapacitors. Based on the experimental results, the enhancement mechanism of electrochemical performances for the CNCs-based supercapacitors was proposed

Enhanced interfacial interaction, mechanical properties and thermal stability of basalt fiber/epoxy composites with multi-scale reinforcements

In this work, epoxy (EP) resin composites with multi-scale reinforcements were prepared by hand lay-up and hot-pressing. The epoxy was reinforced with basalt fibers (BF) modified with a silane coupling agent (KH560). Carboxylated multi-walled carbon nanotubes (CNTs) were also grafted onto the surface of the modified BF using an impregnation method to achieve BF/CNTs multi-scale reinforcement. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) showed that KH560 was successfully grafted onto the BF surface. Scanning electron microscopy (SEM), indicated a better resin adhesion on the BF and thus a stronger interfacial interaction in the BF/CNTs-reinforced composite. It was observed that the mass fraction of KH560 was a significant parameter in achieving desirable CNT immobilization and mechanical properties of the composites. At an optimal mass fraction of KH560 (5%), the tensile, flexural, and interlaminar shear strength (ILSS) of the modified composite (BF-5%KH560-CNT/EP) increased by 12.5%, 20.9%, and 25.5% respectively compared with the BF-washed/EP composite due to more efficient load transfer. In addition, compared with BF-washed/EP, the decomposition onset temperature of BF-5%KH560-CNT/EP increased from 387°C to 396°C, the maximum decomposition rate temperature increased from 400°C to 408°C, and the residual weight increased by 5.8%