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31.
The control of tank systems in industrial applications is an important issue for monitoring the chemical processes involved in the manufacture and delivery of product. The most important reason to control the tank systems is to keep the liquid level in the tanks constant and at the desired level for a specified period of time. In this study, the sliding mode control (SMC) with a repetitive approach called backstepping that is insensitive to uncertainties in system parameters and input disturbances is proposed and experimentally applied to a quadruple, cross‐coupled, uncertain, nonlinear, and multiple‐input/multiple‐output tank system. A proportional‐integral (PI) control is used to reduce the steady‐state error caused by the parameter variations and external noises. The traditional way of introducing PI usually leads to sliding surfaces. In this paper, the PI action is introduced to the control signal. The proposed backstepping sliding mode PI control (BSMPIC) is applied to such a complex tank system for the first time. The experimental results are compared with those of the SMC, sliding mode PI control, and backstepping sliding mode control to see the effect of the proposed BSMPIC on the system. As a result of the comparison, it is observed that less overshoot and tracking error, better tracking performance, and faster rise time in the transient regime is obtained by the BSMPIC. 相似文献
32.
Voltage‐Gated Closed‐Loop Control of Small‐Molecule Release from Alumina‐Coated Nanoporous Gold Thin Film Electrodes
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Precise timing and dosing of potent small‐molecule drugs carries significant potential for effective pharmaceutical management of disorders that exhibit time‐varying therapeutic windows such as epilepsy. This study demonstrates the use of alumina‐coated nanoporous gold (np‐Au) thin film electrodes for iontophoretic release of fluorescein as a small‐molecule drug surrogate with picogram dosing and a few seconds temporal resolution. A custom microfluidic platform is engineered to trigger molecular release from an integrated np‐Au chip and monitor the resulting time‐varying fluorescein concentration. Following a systematic study of the influence of applied voltage on loading capacity and release kinetics, a LabVIEW‐based closed‐loop control interface is employed to demonstrate voltage‐gated fluorescein release with preprogrammed arbitrary concentrations waveforms. 相似文献
33.
Arman Meryem Ozge Geboes Bart Van Hecke Karen Binnemans Koen Cardinaels Thomas 《Journal of Applied Electrochemistry》2022,52(3):583-593
Journal of Applied Electrochemistry - Apart from the generally dominant trivalent oxidation state, several lanthanides can occur in divalent or tetravalent states as well. Changing the valence... 相似文献
34.
ABSTRACT: Dielectric properties can be used to understand the behavior of food materials during microwave processing. Dielectric properties influence the level of interaction between food and high frequency electromagnetic energy. Dielectric properties are, therefore, important in the design of foods intended for microwave preparation. In this study, it was aimed to determine the variation of dielectric properties of different cake formulations during baking in microwave and infrared–microwave combination oven. In addition, the effects of formulation and temperature on dielectric properties of cake batter were examined. Dielectric constant and loss factor of cake samples were shown to be dependent on formulation, baking time, and temperature. The increase in baking time and temperature decreased dielectric constant and loss factor of all formulations. Fat content was shown to increase dielectric constant and loss factor of cakes. 相似文献
35.
Influence of Al concentration on structural and optical properties of Al-doped ZnO thin films 总被引:1,自引:0,他引:1
Deniz Kadir Takci Ebru Senadim Tuzemen Kamuran Kara Sadi Yilmaz Ramazan Esen Ozge Baglayan 《Journal of Materials Science: Materials in Electronics》2014,25(5):2078-2085
Undoped ZnO and Al-doped zinc oxide (ZnO:Al) thin films with different Al concentrations were prepared onto Si (100) substrate by pulsed filtered cathodic vacuum arc deposition system at room temperature. The influence of doping on the structural and optical properties of thin films was investigated. The preferential (002) orientation was weakened by high aluminum doping in films. Raman measurement was performed for the doping effects in the ZnO. Atomic force microscopy images revealed that the surface of undoped ZnO film grown at RT was smoother than that of the Al-doped ZnO (ZnO:Al) films. The reflectance of all films was studied as a function of wavelength using UV–Vis–NIR spectrophotometer. Average total reflectance values of about 35 % in the wavelength range of 400–800 nm were obtained. Optical band gap of the films was determined using the reflectance spectra by means of Kubelka–Munk formula. From optical properties, the band gap energy was estimated for all films. 相似文献
36.
Ozge Sarac Mehtap Caglayan Betul Seher Uysal Ayse Guzin Taslipinar Uzel Burak Tanriverdi Nurullah Cagil 《Contact lens & anterior eye》2018,41(5):442-447
Purpose
To compare the 24 month visual, refractive, topographic and aberrometric results of the accelerated and standard corneal collagen cross-linking (CXL) in pediatric keratoconus patients.Methods
87 eyes of 64 consecutive keratoconus patients under 18 years old with 24 month follow-up period following standard or accelerated CXL were included. 38 eyes received standard CXL (3 Mw/cm2, 30?min), while 49 eyes had accelerated CXL (9?mW/cm2, 10?min). Changes in the uncorrected (UCVA) and best corrected visual acuity (BCVA), spherical equivalent (SE), manifest astigmatism (MA), corneal topographic parameters, and corneal aberrations such as spherical aberration (SA), high order aberrations (HOAs), horizontal and vertical coma were evaluated. Corneal haze was graded and progression rate was assessed.Results
The difference between baseline and 24 months postoperative UCVA, BCVA, SimK (keratometry)-1, SimK-2, Kmax, and the corneal aberrations were not significantly different between the two groups (p?>?0.05 for all). The mean reduction in thinnest corneal pachymetry from baseline to 24 months after CXL was higher in accelerated CXL group (p?=?0.007). The progression rate was 13.1% in standard and 16.3% in accelerated group (p?=?0.754). There were no differences in the grade of corneal haze between the two groups (p?=?0.249). No complications were observed in the both groups.Conclusion
The 24 month results of accelerated and standard CXL revealed that, the efficacy and safety of accelerated CXL were the same with standard CXL in pediatric keratoconus patients. As being a rapid procedure, accelerated CXL appears to be more benefical for pediatric patients. 相似文献37.
Novel fumed silica filled thermoplastic poly(dimethylsiloxane-urea) (TPSU) segmented copolymers were synthesized and characterized. TPSU copolymers were prepared from a cycloaliphatic diisocyanate, aminopropyl terminated PDMS oligomers with number average molecular weights of 3,200, 10,800 and 31,500 g/mol and 2-methyl-1,5-diaminopentane chain extender. Two different types of fumed silica HDK H2000 (hydrophobic) and HDK N20 (hydrophilic) were utilized and incorporated into silicone-urea copolymers in amounts of 1-60% by weight. Influence of the silica type (hydrophilic versus hydrophobic), amount of silica loading and the PDMS soft segment molecular weight on the morphology, tensile properties and modulus-temperature behavior of the nanocomposites were determined. Major observations of this study were: (i) under the blending conditions used, incorporation of silica does not seem to interfere significantly with the hydrogen bonding between urea groups, (ii) incorporation of silica does not affect the glass transition temperature of PDMS, (iii) incorporation of silica influences the tensile and thermomechanical properties of silicone-urea segmented copolymers significantly, (iv) average molecular weight of the PDMS soft segment in the silicone-urea copolymer plays a critical role on the improvement of the tensile properties of the fumed silica/TPSU composites. 相似文献
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39.
Kevser Kahraman Ozge Sakıyan Serpil Ozturk Hamit Koksel Gulum Sumnu Arnaud Dubat 《European Food Research and Technology》2008,227(2):565-570
The objective of this study was to determine the possibility of using Mixolab® to predict the cake baking quality of different wheat flours. Mixolab® data were also compared with various flour quality characteristics. The correlations between Alveoconsistograph data and the cake quality characteristics were not significant. Therefore, Alveoconsistograph test does not seem to be useful to predict the cake quality of the flour samples. Mixolab® characteristics C2, C3, C4 and C5 were found to be significantly correlated with volume index while C5 was correlated with hardness of cakes. The parameters C2 to C5 represent the end point of the corresponding mixing stages. The flour samples which gave higher cake hardness values had higher C5 values and the samples with lower cake volumes had higher C2, C3, C4 and C5 values. It seems to be possible to estimate the texture and volume of cakes by these values. Therefore, Mixolab® seems to be a useful tool to predict the cake making quality of flour samples. 相似文献
40.
The adsorption kinetics and removal of cationic dye, Toluidine Blue O, from aqueous solution with Turkish zeolite 总被引:3,自引:1,他引:3
Clinoptilolite, a natural zeolite, was investigated as an inexpensive and effective adsorbent for the adsorption of Toluidine Blue O (TBO) from its aqueous solution. The effect of parameters such as the initial concentration of TBO, the solution of pH, contact time, temperature and particle size on the TBO adsorption was examined. The adsorption rate data were analysed according to the first and second-order kinetic models. Kinetic studies show that adsorption of TBO on clinoptilolite was fitted to the second-order adsorption model with two-step diffusion process. The activation energies for TBO adsorption on clinoptilolite for the first and second diffusion processes were 8.72 kJ mol(-1) and 19.02 kJ mol(-1), respectively. The adsorption isotherm was well fitted to both the Langmuir and Freundlich models. The maximum adsorption capacity of clinoptilolite for TBO was 2.1x10(-4) mol g(-1) at solution pH of 11.0. 相似文献