Data-driven approach for time-delay estimation of industrial processes.

An accurate estimate of time delay is of crucial importance for control tasks such as performance assessment and controller design. In this paper, a novel data-driven approach to time-delay estimation is developed for a process subject to industrial background disturbances, in which the closed-loop output data under the routine operating conditions is only required. The practical solutions are proposed to estimate the time delay based on the estimated impulse response of the closed loop that is estimated online by utilizing the output data. Without relying on system identification and any prior knowledge of the process as well, the time delay is estimated directly for a large time delayed process; while for a small time delayed process, the time delay is estimated by means of the stationarilized filter, the pre-filter and the loop filter. The effectiveness of the proposed approach is validated by various numerical and industrial examples including a distillation column, a petroleum refinery heating furnace and a ceramic dryer.

A data-driven approach for on-line auto-tuning of minimum variance PID controller.

A data-driven approach for on-line tuning of minimum variance (MV) PID controller is proposed in this paper for a linear system subject to stochastic disturbances, in which none of a prior knowledge or/and external excitation signals is required. The main procedure is that two different rough tuning controllers are employed and switched from one to another such that two sets of output data are collected under routine operating conditions. Subsequently, based on FCOR (Filtering and CORrelation analysis) algorithm, the corresponding linear MV controller is estimated on-line for the linear system. The parameters of MV-PID controller is tuned to approximate the estimated MV controller by means of solving an optimization problem subject to a constraint of the closed-loop stability, where the weighted penalty function is composed of the inverse of controller parameters and the difference between the proposed controller and the minimum variance controller. By using a different selection of the weighting coefficients in the penalty function, the final tuning parameters of MV-PID controllers are determined by the practical consideration of step disturbance attenuation or sometimes the trade-off between stochastic and step signal disturbance attenuation.

Bioaugmentation of Exogenous Strain Rhodococcus sp. 2G Can Efficiently Mitigate Di(2-ethylhexyl) Phthalate Contamination to Vegetable Cultivation.

This work developed a bioaugmentation strategy that simultaneously reduced soil di(2-ethylhexyl) phthalate (DEHP) pollution and its bioaccumulation in Brassica parachinensis by inoculating the isolated strain Rhodococcus sp. 2G. This strain could efficiently degrade DEHP at a wide concentration range from 50 to 1600 mg/L and transformed DEHP through a unique biochemical degradation pathway that distinguished it from other Rhodococcus species. Besides, strain 2G colonized well in the rhizosphere soil of the inoculated vegetable without competition with indigenous microbes, resulting in increased removal of DEHP from soil (∼95%) and reduced DEHP bioaccumulation in vegetables (∼75% in the edible part) synchronously. Improved enzyme activities and DOC content in the rhizosphere of the planting vegetable and inoculating strain 2G were responsible for the high efficiency in mitigating DEHP contamination to vegetable cultivation. This work demonstrated a great potential application to grow vegetables in contaminated soil for safe food production.

Differences in Root Physiological and Proteomic Responses to Dibutyl Phthalate Exposure between Low- and High-DBP-Accumulation Cultivars of Brassica parachinensis.

Di- n-butyl phthalate (DBP), as an endocrine-disrupting chemical that tends to be accumulated in crops, poses great risks to human health through the food chain. To identify the molecular mechanism underlying differences in their DBP accumulation, the root physiological and proteomic responses to DBP stress of two Brassica parachinensis cultivars, a high-DBP accumulator (Huaguan) and a low-DBP accumulator (Lvbao), were investigated. Root damage of greater severity and significantly greater ( p < 0.05) decreases in root protein content and root activity were detected in Lvbao than in Huaguan, suggesting that Lvbao had lower tolerance to DBP. In total, 52 DBP-responsive proteins were identified by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. More proteins involved in basic metabolic processes, such as protein synthesis and energy metabolism, were downregulated in Lvbao, possibly explaining its lower tolerance and root damage. Several proteins involved in starch metabolism, cell-wall biosynthesis and modification, and stress response were activated in Huaguan, suggesting greater tolerance to DBP. Overall, differences in root proteome between the two cultivars might be responsible for the genotype-dependent DBP tolerance and accumulation in B. parachinensis.

[Optimization of extraction procedure of psammosilene tunicoides by uniform design with pharmacodynamic index].

OBJECTIVE: For anti-inflammation, relieving pain and decreasing acute toxicity, the best condition for extracting procedure of Psammosilene tunicoides was chosen. And the relationships between several solvent extracts and pharmacodynamic index were studied. METHOD: Uniform design with multi-targets was used in the optimization process, and the evaluate index were the results of anti-inflammation, relieving pain and LD50 were employed as the evaluating indexes. At the same time, the contents of the extracts, water extract, acetic ester extract and ether extract were determined. RESULT: The best condition is that the medicinal material is optimized with 8 times of water (pH 6-7) and 2 h of each time. The best condition is satisfactory by test verification. And the pharmacodynamic actions of anti-inflammation, relieving pain and LD, were not obviously related to the dry extracts, water extract, acetic ester extract and ether extract. CONCLUSION: Uniform design method with pharmacodynamic index has the merit of being relaated to the function and symptom directly. The extracted twice technology condition optimized is stable, feasible and suitable for industry production. And it is not suitable to take the solvent extracts as quality control index related to the function and symptom.