Biological growth is driven by numerous functions, such as hormones and mineral nutrients, and is also involved in various ecological processes. Therefore, it is necessary to accurately capture the growth trajectory of various species in ecosystems. A new sigmoidal growth (NSG) model is presented here for describing the growth of animals and plants when the assumption is that the growth rate curve is asymmetric. The NSG model was compared with four classic sigmoidal growth models, including the logistic equation, Richards, Gompertz, and ontogenetic growth models. Results indicated that all models fit well with the empirical growth data of 12 species, except the ontogenetic growth model, which only captures the growth of animals. The estimated maximum asymptotic biomass wmax of plants from the ontogenetic growth model was not reliable. The experiment result shows that the NSG model can more precisely estimate the value and time of reaching maximum biomass when growth rate becomes close to zero near the end of growth. The NSG model contains three other parameters besides the value and time of reaching maximum biomass, and thereby, it can be difficult to assign initial values for parameterization using local optimization methods (e.g., using Gauss–Newton or Levenberg–Marquardt methods). We demonstrate the use of a differential evolution algorithm for resolving this issue efficiently. As such, the NSG model can be applied to describing the growth patterns of a variety of species and estimating the value and time of achieving maximum biomass simultaneously.

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Isobaric vapor−liquid equilibrium (VLE) data for the binary system methanol + dimethyl carbonate as well as the VLE data for the ternary systems methanol + dimethyl carbonate +1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTf]) and methanol + dimethyl carbonate + 1butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM][OTf]) at 101.3 kPa have been obtained with a modified Othmer still. The results indicated that both [EMIM][OTf] and [BMIM][OTf] produced crossover effects. Due to the difference of polarity of the two ILs, [BMIM][OTf] eliminated the azeotropic point at mole fraction about 10%, whereas [EMIM][OTf] only pulled down the azeotropic point. The measured VLE data were fitted using the NRTL model with a good consistency.

Vapor−liquid equilibria for the binary system ethyl acetate + acetonitrile and for the ternary system ethyl acetate + acetonitrile + 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM] + [PF 6 ] − ) at 101.3 kPa have been obtained with a modified Othmer still. The experimental vapor−liquid equilibrium data were correlated using the NRTL model proposed by Renon and Prausnitz, and the parameters were obtained. The results showed that [BMIM] + [PF 6 ] − produced a consistent salting-out effect of ethyl acetate over the whole range of the liquid concentrations, which increased the relative volatility of ethyl acetate to acetonitrile and even eliminated the azeotropic phenomenon when the mole fraction of [BMIM] + [PF 6 ] − was up to 0.05.

In this paper, a novel fuzzy adaptive nonlinear fault tolerant control design scheme is proposed for attitude dynamics of quadrotor UAV subjected to four sensor faults (bias, drift, loss of accuracy, loss of effectiveness). The sensor faults in Euler angle loop are transformed equivalently into a mismatched uncertainty vector, and other unknown items involving faults, uncertain parameters and external disturbances in angular velocity loop are lumped into an unknown nonlinear function vector.Fuzzy logic systems with adaptive parameters are used to approximate the mismatched uncertainty and lumped nonlinear function vectors. Dynamic surface control is applied to design the fault tolerant controller, and sliding mode control is introduced to improve the control accuracy. All signals of the closed-loop control system are proved to be semi-global uniformly ultimately bounded. Simulations demonstrate the effectiveness of the proposed approach for sensor faults. KEYWORDS dynamic surface control, fault tolerant control, fuzzy logic system, Quadrotor unmanned aerial vehicle, sensor fault, sliding mode control

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