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1.
ACS Omega ; 9(5): 5715-5727, 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38343946

ABSTRACT

Concentrated coal slime serves as a clean and promising fluid fuel and is commonly employed via pipeline transportation. Currently, there are still limitations in understanding the rheological properties of coal slime, including its yield stress, viscoelasticity, and the impact of factors, such as temperature, on these properties. Therefore, we conducted tests to examine the rheological properties and yield stress of coal slime at various temperatures for two different concentrations using a pipeline transportation system and rheometers. Furthermore, due to the challenges in measuring dynamic yield stress caused by the shear bands of highly viscous slime, a method using the residual pressure inside the pipeline after cessation of transportation is proposed. The viscoelasticity of coal slime at various temperatures was examined through oscillatory shear tests. Finally, the pressure wave velocity in the pipeline transportation system was used to determine the bulk modulus. The results indicated that the shear stress under high shear rates decreased with an increase in temperature, while the yield stress and shear stress under low shear conditions gradually increased with temperature. The coal slime exhibited certain viscoelasticity with shear elasticity increasing as the temperature rose. The pressure wave velocity in the pipeline remained constant and did not vary significantly with temperature.

2.
IEEE Trans Neural Netw Learn Syst ; 33(11): 6545-6557, 2022 11.
Article in English | MEDLINE | ID: mdl-34057897

ABSTRACT

A novel robust adaptive neural network (NN) control scheme with prescribed performance is developed for the 3-D trajectory tracking of underactuated autonomous underwater vehicles (AUVs) with uncertain dynamics and unknown disturbances using new prescribed performance functions, an additional term, the radial basis function (RBF) NN, and the command-filtered backstepping approach. Different from the traditional prescribed performance functions, the new prescribed performance functions are innovatively proposed such that the time desired for the trajectory tracking errors of AUVs to reach and stay within the prescribed error tolerance band can be preset exactly and flexibly. The additional term with the Nussbaum function is designed to deal with the underactuation problem of AUVs. By means of RBF NN, the uncertain item lumped by the uncertain dynamics of AUVs and unknown disturbances is eventually transformed into a linearly parametric form with only a single unknown parameter. The developed control scheme ensures that all signals in the AUV 3-D trajectory tracking closed-loop control system are bounded. Simulation results with comparisons show the validity and the superiority of our developed control scheme.


Subject(s)
Neural Networks, Computer , Nonlinear Dynamics , Computer Simulation , Uncertainty
3.
Foodborne Pathog Dis ; 18(11): 790-797, 2021 11.
Article in English | MEDLINE | ID: mdl-34287022

ABSTRACT

The prevalence of Salmonella serovar 1,4,[5],12:i:- among diarrhea patients has increased considerably in many countries around the world, including China. However, the characterization of this serovar of human origin has been less reported from China. We characterized 76 isolates of Salmonella 1,4,[5],12:i:- gained from diarrhea patients from 2014 to 2018 in the Jiangsu Province of eastern China. These isolates fell into a single-sequence type (ST34) determined by multilocus sequence typing (MLST), and into 44 pulsed-field gel electrophoresis band patterns, with 1 pattern (JSSMM015) comprising 12 isolates (15.9%). By means of PCR-based assays, the seven prophage located virulence genes were detected in our Salmonella 1,4,[5],12:i:- isolates with a high rate of gipA, gtgB, sspH1, sspH2, sodC1, and gtgE (93.4-97.4%), and with a moderate rate of sopE (42.1%). In contrast, none of the five plasmid-borne virulence genes (spvC, pefA, mig5, rck, and srgA) was identified. We tested the isolates' susceptibility to 18 antibiotics of 9 categories using the VITEK 2 system. A high proportion (89.5%) of the isolates were multidrug resistant (MDR) strains with full resistance to cefazolin, cefotetan, amikacin, gentamycin, and tobramycin, followed by resistance to ampicillin (88.2%) and ampicillin/sulbactam (80.3%). The resistance to piperacillin/tazobactam, ceftazidime, cefepime, and levofloxacin was scarce (2.6-9.2%). Notably, an isolate from 2018 was resistant to carbapenems. blaTEM-1B and aac(6')-Ib-cr were the most common drug resistance genes presented in cephalosporin- and fluoroquinolone-resistant strains. All Salmonella 1,4,[5],12:i:- isolates were capable of forming biofilm, with 13.2% of them having strong ability. However, no association was indicated between the scale of biofilm formation ability and MDR. Our results indicate that the combination of these characteristics may together provide a selective and competitive advantage to those Salmonella 1,4,[5],12:i:- isolates, contributing to their increasing prevalence observed worldwide.


Subject(s)
Drug Resistance, Multiple, Bacterial , Salmonella , Anti-Bacterial Agents/pharmacology , China/epidemiology , Drug Resistance, Multiple, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Humans , Microbial Sensitivity Tests , Multilocus Sequence Typing , Salmonella/genetics , Serogroup
4.
ISA Trans ; 96: 14-23, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31421802

ABSTRACT

In this paper, we develop an adaptive disturbance cancellation tracking control strategy with the asymptotically converging output tracking errors for a class of multi-input and multi-output (MIMO) nonlinear Euler-Lagrange systems with unknown time-varying disturbances under input saturation. The unknown time-varying disturbances are firstly described as the outputs of a multivariate linear unknown exosystem with unavailable regressor and regression parameter. To estimate the unavailable regressor, an observer is constructed, such that the disturbance cancellation is converted to an adaptive control problem. An auxiliary dynamic system (ADS) is employed to mitigate the effect of the input saturation. Then, a robust adaptive tracking control law is proposed incorporating the above and a robustifying term into the adaptive vectorial backstepping design tool. It is proven theoretically that the asymptotic convergence of the output tracking errors of Euler-Lagrange systems is achieved, while the uniform ultimate boundedness of the remaining signals of the resulting closed-loop control system is guaranteed. Simulation and comparison results on a two-link rigid manipulator and a scale model ship are presented to illustrate the effectiveness and the superiority of the proposed control scheme.

5.
Am J Cancer Res ; 5(4): 1353-67, 2015.
Article in English | MEDLINE | ID: mdl-26101702

ABSTRACT

Cervical cancer is a common and devastating female cancer worldwide. The etiology of cervical cancer has been largely attributed to human papillomavirus (HPV) infection and activation of the P13K/AKT/mTOR (mammalian target of rapamycin) pathway. However, the limited HPV-directed therapy, as well as therapeutic approach targeting P13K/AKT/mTOR pathway, has not yet been established or effective. A deeper understanding of cervical carcinogenesis and finding of novel candidate molecules for cervical cancer therapeutics is largely warranted. The unconventional prefoldin RPB5 interactor (URI or URI1), a known transcription factor involving the TOR signaling pathway, has recently been implicated a role in multiple tumorigenesis. We recently reported significant upregulation of URI in precancerous cervical intra-epithelial neoplasia (CIN) and invasive cervical cancer, suggesting its role in cervical carcinogenesis. However, the effect and underlying mechanism of URI in cervical cancer development have never been elucidated. Here, we aimed to investigate the in vitro effect of URI on cervical cancer using two cervical cancer cell lines CaSki and C33A, which are HPV-positive and HPV-negative respectively. We have shown that forced over-expression of URI in C33A and CaSki cells markedly promoted cell growth, while down-regulation of URI mediated by siRNA inhibited cell proliferation. We have found that URI over-expression enhanced resistance of cervical cancer cells to cisplatin. In contrast, knockdown of URI promoted apoptosis by influencing cell response to cisplatin, supporting URI as an oncogenic protein for cervical cancer cells. We have also shown that URI promoted the migration and invasive capacity of cervical cancer cells by up-regulation of Vimentin, a mesenchymal cell migration marker relating to the epithelial-mesenchymal transition (EMT) program. Our data support an important function of URI in the biological behavior of cervical cancer cells and provide novel mechanistic insights into the role of URI in cervical cancer progression and possibly, metastasis.

6.
IEEE Trans Neural Netw Learn Syst ; 26(11): 2775-86, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25769172

ABSTRACT

This paper develops an adaptive robust output feedback control scheme for dynamically positioned ships with unavailable velocities and unknown dynamic parameters in an unknown time-variant disturbance environment. The controller is designed by incorporating the high-gain observer and radial basis function (RBF) neural networks in vectorial backstepping method. The high-gain observer provides the estimations of the ship position and heading as well as velocities. The RBF neural networks are employed to compensate for the uncertainties of ship dynamics. The adaptive laws incorporating a leakage term are designed to estimate the weights of RBF neural networks and the bounds of unknown time-variant environmental disturbances. In contrast to the existing results of dynamic positioning (DP) controllers, the proposed control scheme relies only on the ship position and heading measurements and does not require a priori knowledge of the ship dynamics and external disturbances. By means of Lyapunov functions, it is theoretically proved that our output feedback controller can control a ship's position and heading to the arbitrarily small neighborhood of the desired target values while guaranteeing that all signals in the closed-loop DP control system are uniformly ultimately bounded. Finally, simulations involving two ships are carried out, and simulation results demonstrate the effectiveness of the proposed control scheme.


Subject(s)
Feedback , Geographic Information Systems , Neural Networks, Computer , Nonlinear Dynamics , Robotics/methods , Ships , Algorithms , Environment , Humans
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