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Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China, and its components, which include ultrafine particles (UFPs), volatile organic compounds (VOCs), and other reactive gases, such as NH

Introduction: Model predictive control (MPC) is an advanced control strategy which can achieve fast reference tracking response and deal with process constraints, time delay and multivariable problems. However, thermal processes in coal-fired power plants are usually difficult to model accurately, which limits the application of MPC to thermal power plants.Methods: To solve the problem, this paper proposes a process-model-free method for MPC via a reference model (RM)-based controller, i.e., a desired dynamic equational (DDE) proportional-integral-derivative (PID) controller (DDE-PID).Results and Discussion: The DDE-PID can provide the design model and enhance the disturbance rejection ability for MPC. Simulations and results of field tests on a coal-fired unit show the superiorities of the proposed controller in reference tracking, disturbance rejection and robustness, which indicates the promising prospect of the field application of the MPC with DDE-PID, or MPC-DDE in short, to thermal power plants.

This paper deals with the conflict between the input-output response and the disturbance-output response, which cannot be completely eliminated by traditional and advanced control strategies without using the accurate process model. The inherently close association of these two responses and the unavailability of the accurate process model pose a great challenge to field test engineers of a coal-fired power plant, that is, the design requirements of reference tracking and disturbance rejection are compromised. In this paper, a novel two-degree-of-freedom controller-feedforward compensated (FC) desired dynamic equational (DDE) proportional-integral-derivative (PID) (FC-DDE PID)-is proposed as a viable alternative. In addition to achieving independent reference tracking performance and disturbance rejection performance, its simple structure and tuning procedure are specifically appealing to practitioners. Simulations, experiments, and field tests demonstrate the advantages of the proposed controller in both reference tracking and disturbance rejection, thus making FC-DDE PID a convenient and effective controller for the control of the coal-fired power plants, readily implementable on the distributed control system (DCS).

The fabrication of smart materials, which can efficiently mimic biological systems through the introduction of soft components, is of great importance in the emerging fields of sensors and actuators. Herein, a smart composite film that can mechanically respond to vapors trigger then readily restores its original shape upon the removal of the stimuli is reported. This actuating composite film was prepared by mixing the highly elastic poly (vinylidene fluoride) (PVDF) polymer with the flexible and crystalline organic cages (Oba-cage) at variable concentrations. The mechanism of the mechanical response could be accurately recorded due to the ordered cage crystals. This work highlights the importance of designing smart materials at the molecular level to precisely control the response or reaction upon the introduction of different triggers, which can ultimately lead to a monumental leap in the field of soft robotics.

This work models spatially uncorrelated (independent) load uncertainty and develops a reduced-order Monte Carlo stochastic isogeometric method to quantify the effect of the load uncertainty on the structural response of thin shells and solid structures. The approach is tested on two demonstrative applications of uncertainty, namely, spatially uncorrelated loading, with (1) Scordelis–Lo Roof shell structure, and (2) a 3D wind turbine blade. This work has three novelties. Firstly, the research models spatially uncorrelated (independent) load uncertainties (including both their magnitude and/or direction) using stochastic analysis. Secondly, the paper advances a reduced-order Monte Carlo stochastic isogeometric method to quantify the spatially uncorrelated load uncertainty. It inherits the merits of isogeometric analysis, which enables the precise representation of geometry and alleviates shell shear locking, thereby reducing the model’s uncertainties. Moreover, the method retains the generality and accuracy of classical Monte Carlo simulation (MCS), with significant efficiency gains. The demonstrative results suggest that there is a cost, which is 3% of the time used by the standard MCS. Furthermore, a significant observation is made from the conducted numerical tests. It is noticed that the standard deviation of the output (i.e., displacement) is strongly influenced when the load uncertainty is spatially uncorrelated. Namely, the standard derivation (SD) of the output is roughly 10 times smaller than the SD for correlated load uncertainties. Nonetheless, the expected values remain consistent between the two cases.

Distillation-free separations of haloalkane isomers represents a persistent challenge for the chemical industry. Several classic molecular sorbents show high selectivity in the context of such separations; however, most suffer from limited tunability or poor stability. Herein, we report the results of a comparative study involving three trianglamine and trianglimine macrocycles as supramolecular adsorbents for the selective separation of halobutane isomers. Methylene-bridged trianglamine, TA, was found to capture preferentially 1-chlorobutane (1-CBU) from a mixture of 1-CBU and 2-chlorobutane (2-CBU) with a purity of 98.1%. It also separates 1-bromobutane (1-BBU) from a mixture of 1-BBU and 2-bromobutane (2-BBU) with a purity of 96.4%. The observed selectivity is ascribed to the thermodynamic stability of the TA-based host–guest complexes. Based on single crystal X-ray diffraction analyses, a [3]pseudorotaxane structure (2TA⊃1-CBU) is formed between TA and 1-CBU that is characterized by an increased level of noncovalent interactions compared to the corresponding [2]pseudorotaxane structure seen for TA⊃2-CBU. We believe that molecular sorbents that rely on specific molecular recognition events, such as the triangular pores detailed here, will prove useful as next generation sorbents in energy-efficient separations., The methylene-bridged trianglamine (TA) can selectively capture 1-chlorobutane from a mixture of 1-chlorobutane and 2-chlorobutane due to the greater thermodynamic stability of the TA-based host–guest complex formed with 1-chlorobutane.

To reveal the fuel ignition delay differences among diluent gases, non-reactive gas Ar, He, N2 and reactive gas CO2 four gases were selected to compare the ethylene ignition delay difference on a shock tube rig. The tested condition temperature and pressure range is 1074–1832 K and 2 atm. Comparison results show that the ethylene ignition delay discrepancy was not pronounced among Ar, He and N2 these non-reactive dilution gases. In terms of CO2 dilution, a critical CO2 concentration was observed. When the CO2 concentration was lower than this critical value, no distinguished ignition delay difference was found. Conversely, the ignition delay difference was pronounced once the CO2 concentration was above this critical value. Particularly, the difference was specially apparent in low temperature conditions. Reaction dynamic analysis shows that the heat effect is predominant in low temperature while the chemical effect is predominant in high temperature in the reaction of CO2 participation. Additionally, the CH* and OH* radical emission signal intensity turns smaller and profile curve turns irregular as the CO2 ratio increases. The CO2 shows a strong inhibition effect which is closely related with H radical consumption reaction CO2+H CO + OH.

As a clean energy engine, the gas turbine has many challenges in its shaft speed control such as strong nonlinearity and various external disturbances. However, conventional controllers such as proportional-integral-derivative (PID) controllers are not able to obtain satisfactory performance in disturbance rejection when the operating point is changing. To handle with the strong nonlinearity and reject possible disturbances more effectively, the linear active disturbance rejection controller (LADRC) is applied to the shaft speed control system of the gas turbine based on an experimental tuning procedure. Moreover, Skogestad Internal Model Control-PID (SIMC-PID) and fractional order PID (FOPID) are chosen as comparative controllers. Eventually, Monte Carlo trials are carried out and maximum sensitivities are calculated in order to test the robustness of controllers. Simulation results illustrate the advantages of LADRC in both reference tracking and rejections of different disturbances.

The separation of α-olefins and their corresponding isomers continues to be a big challenge for the chemical industry due to their overlapping physical properties and low relative volatility. Herein, pillar[3]trianglamine (P-TA) macrocycles were synthesized for the molecular-sieving-like separation of 1-hexene (1-He) selectively over its positional isomer

This paper deals with high-order unstable systems, which are dangerous and more difficult to control. Their presence is increasingly prevalent, posing a great challenge to both traditional PID-based industrial designs and various advanced control strategies which are difficult to implement on common industrial control platforms. In this paper, the generalized desired dynamic equational (G-DDE) PID controller, developed by authors earlier, is proposed as a viable alternative. In addition to guarantee the closed-loop stability, its simple structure and tuning procedure are specifically appealing to practitioners. Simulations and experimental results show advantages of G-DDE PID in reference tracking, disturbance rejection and robustness, thus making G-DDE PID a convenient and effective control strategy for high-order unstable systems, readily implementable on common industrial platforms.

This study aimed to identify the genes and small RNAs (sRNAs) expressed by the human endogenous retrovirus K (HERV-K) HML2 and their associations with the immune process of systemic lupus erythematosus (SLE). RNA-Seq data including 99 SLE patients and 18 controls (GSE72420) was obtained from the Gene Expression Omnibus. Differentially expressed genes (DEGs) as well as HML2-DEGs between SLE patients and normal controls were identified. Five HML2-DEGs involved in immune-regulating function were identified using weighted gene co-expression network analysis. The associations between these genes and the proportions of immune cells were determined by CIBERSORT. Ten candidate HML2-encoded sRNAs were identified based on specific criteria, and three of them were further validated in SLE patients by qRT-PCR. The diagnostic values of these three sRNAs were evaluated in SLE and lupus nephritis (LN). This study suggested that HML2 genes and their encoded sRNAs might be involved in the immune regulation and progress of SLE. These potential sRNAs might function as regulatory molecules and diagnostic biomarkers of SLE and LN.

In order to research kinetics properties of hydrogen-enriched n-butane mixtures, this study measured the ignition delay time of nC 4 H 10 /H 2 mixtures in shock tube tests and time-resolved CO 2 concentrations during combustion process by combining laser absorption diagnostics. The experimental data were compared with numerical predictions from three kinetic mechanisms, and the modified NUIG Mech shows improved performances in predicting ignition delay time and time-resolved CO 2 concentrations. Higher nC 4 H 10 :H 2 ratio led to lower reactivities because the main combustion happens after the oxidation of nC 4 H 10 . Lean mixtures ( ϕ = 0.5) ignites significantly faster than stoichiometric mixtures. It is possible to adjust ratios of nC 4 H 10 to H 2 in fuel mixture to fit the combustor design because of the varying combustion characteristics. The CO 2 formation occurs after complete oxidation of nC 4 H 10 with the primary sources being small molecules or radicals. Reaction path analyses show that nearly half of the CO 2 is formed through the reaction CO + OH = CO 2 + H.

Structural stochastic analysis is vital to engineering. However, current material related uncertainty methods are mostly limited to low dimension, and they mostly remain unable to account for spatially uncorrelated material uncertainties. They are not representative of realistic and practical engineering situations. In particular, it is more serious for composite structures comprised of dissimilar materials. Therefore, we propose a novel model order reduction via proper orthogonal decomposition accelerated Monte Carlo stochastic isogeometric method (IGA-POD-MCS) for stochastic analysis of exactly represented (composite) structures. This approach particularly enables high-dimensional material uncertainties wherein the characteristics of each element are independent. And the novelties include: (1) the structural geometry is exactly modeled thanks to isogeometric analysis (IGA), as well as providing more accurate deterministic and stochastic solutions, (2) we innovatively consider high-dimensional and independent material uncertainties by separating the stochastic mesh from the IGA mesh, and modeling different stochastic elements to have different (independent) uncertainty behaviors, (3) the classical Monte Carlo simulation (MCS) is employed to universally solve the high-dimensional uncertainty problem. However, to circumvent its computational expense, we employ model order reduction via proper orthogonal decomposition (POD) into the IGA coupled MCS stochastic analysis. In particular, we observe that this work decouples all IGA elements and hence permits independent uncertainty models easily, thereby the engineering problem is modeled to be more realistic and authentic. Several illustrative numerical examples verify the proposed IGA-POD-MCS approach is effective and efficient; and the larger the scale of the problem is, the more advantageous the method will become.

Linestrengths, self-broadening and narrowing coefficients for 8 absorption transitions of CO2 near 1.43 µm were measured using the wavelength modulation direct absorption spectroscopy (WM-DAS) at 300–1000 K and 5–20 kPa. The SNR was enhanced to 1500 for the peak absorbance around 5% at room temperature and remains at 550 for the peak absorbance around 1% at high temperatures by use of the WM-DAS method. The Voigt, Rautian, Galatry and quadratic speed-dependent Voigt profiles were used to recover the absorbance and retrieve the best-fit spectroscopic parameters and their temperature dependence. The quadratic speed-dependent Voigt profile was found to give the best combination of accuracy and robust lineshape parameters. The measured linestrengths and self-broadening coefficients compare well with the available values listed in the HITRAN/HITEMP database. The self-narrowing coefficients were also determined for GP, RP and qSDVP with analyses of the uncertainties in these spectroscopic parameters.

Flualprazolam, a new benzodiazepine psychoactive substance recently made available online, and outside the controlled substance list, is often used by criminals for rape and robbery. In this paper, flualprazolam was successfully identified by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) and nuclear magnetic resonance (NMR). Moreover, LC-Q-TOF-MS analysis method was proposed for the determination of flualprazolam in whole blood using the rabbit perfusion model. After metabolism analysis, a monohydroxylated metabolite 3-hydroxy-flualprazolam was found in the primary mass spectrum of metabolites. Meanwhile, the time effect curve of the flualprazolam in rabbit's blood was explored and the detection window was about 36 h. Moreover, the sensitivity of the established LC-Q-TOF-MS method was investigated with the limit of detection of 0.03 ng/mL. The successful analysis of an actual forensic case with this established method suggests that it might provide a reference method for drug detection or supervision in law enforcement agencies and identification institutions.