Robust output maneuvering for a class of nonlinear systems

The output maneuvering problem involves two tasks. The first, called the geometric task, is to force the system output to converge to a desired path parametrized by a continuous scalar variable θ. The second task, called the dynamic task, is to satisfy a desired dynamic behavior along the path. This dynamic behavior is further specified via a time, speed, or acceleration assignment. While the main concern is to satisfy the geometric task, the dynamic task ensures that the system output follows the path with the desired speed. A robust recursive design technique is developed for uncertain nonlinear plants in vectorial strict feedback form. First the geometric part of the problem is solved. Then an update law is constructed that bridges the geometric design with the speed assignment. The design procedure is illustrated through several examples.     

Cryogels of cellulose derivatives prepared via UV irradiation of moderately frozen systems

Cryogels of non-ionic (hydroxypropyl)methylcellulose, 2-hydroxyethylcellulose, methylcellulose and cationic hydroxyethylcelluloses were prepared for the first time via UV irradiation of moderately frozen systems. The influence of the irradiation time, the concentration of the photoinitiator (4-benzoylbenzyl)trimethylammonium chloride, and the concentration of the polymer solution on the efficiency of the cross-linking process in moderately frozen systems was investigated. It was found that 2-min irradiation at an irradiation dose rate of 5.7 J/cm² min is adequate for cross-linking of 3 wt.% polymer solutions resulting in high quality cryogel.     

Control of linear systems with multiparameter singular perturbations

The singular perturbation theory is extended to systems with several small parameters which can change the system order. Difficulties arising in testing the boundary layer stability in multiparameter linear problems are discussed. The theory is applied to linear quadratic optimal control and Nash game problems.     

An amorphous model for morphological processing in visual comprehension based on naive discriminative learning.

A 2-layer symbolic network model based on the equilibrium equations of the Rescorla–Wagner model (Danks, 2003) is proposed. The study first presents 2 experiments in Serbian, which reveal for sentential reading the inflectional paradigmatic effects previously observed by Milin, Filipovi? ?ur?evi?, and Moscoso del Prado Martín (2009) for unprimed lexical decision. The empirical results are successfully modeled without having to assume separate representations for inflections or data structures such as inflectional paradigms. In the next step, the same naive discriminative learning approach is pitted against a wide range of effects documented in the morphological processing literature. Frequency effects for complex words as well as for phrases (Arnon & Snider, 2010) emerge in the model without the presence of whole-word or whole-phrase representations. Family size effects (Moscoso del Prado Martín, Bertram, H?iki?, Schreuder, & Baayen, 2004; Schreuder & Baayen, 1997) emerge in the simulations across simple words, derived words, and compounds, without derived words or compounds being represented as such. It is shown that for pseudo-derived words no special morpho-orthographic segmentation mechanism, as posited by Rastle, Davis, and New (2004), is required. The model also replicates the finding of Plag and Baayen (2009) that, on average, words with more productive affixes elicit longer response latencies; at the same time, it predicts that productive affixes afford faster response latencies for new words. English phrasal paradigmatic effects modulating isolated word reading are reported and modeled, showing that the paradigmatic effects characterizing Serbian case inflection have crosslinguistic scope. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

An Unique SPICE Model of Photodiode with Slowly Changeable Carriers’ Velocities

This paper deals with a relatively new SPICE model of a P-i-N photodiode. The model includes a change of velocities of electrons and holes, due to the voltage drop on the edges of the photodiode, which depends on the time form of input excitation. We have derived the model of the P-i-N photodiode for digital input excitation i.e. for Heaviside’s square wave time excitation. The model is incorporated in SPICE program and simulated with it. The model and the limitations of the model itself are observed. The output results are compared with the similar ones. It is suggested when it is practical to use the model, and determined the photodiode working domain regime when the model gives accurate results.     

Short communication: Effect of commercial or depurinized milk diet on plasma advanced oxidation protein products,cardiovascular markers,and bone marrow CD34 stem cell potential in rat experimental hyperuricemia

Cardiovascular repair and myocardial contractility may be improved by migration of bone marrow stem cells (BMSC) and their delivery to the site of injury, a process known as BMSC homing. The aim of our study was to examine the dietary effect of a newly patented depurinized milk (DP) that is almost free of uric acid and purine and pyrimidine compounds compared with a standard commercial 1.5% fat UHT milk diet or allopurinol therapy in rat experimental hyperuricemia. Bone marrow stem cell potential (BMCD34⁺, CD34-postive bone marrow cells), plasma oxidative stress parameters [advanced oxidation protein products, AOPP) and thiobarbituric acid reactive substances (TBARS)], myocardial damage markers [creatine phosphokinase (CPK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH)], plasma cholesterol, and high-density lipoprotein cholesterol were investigated. The DP milk diet significantly increased the number of BMCD34⁺ stem cells compared with commercial UHT milk. Allopurinol given alone also increased the number of BMCD34⁺. Hyperuricemia caused a significant increase in all plasma enzyme markers for myocardial damage (CPK, LDH, and AST). A cardioprotective effect was achieved with allopurinol but almost equally with DP milk and more than with commercial milk. Regarding plasma AOPP, TBARS, and cholesterol levels, the most effective treatment was DP milk. In conclusion, the protective role of a milk diet on cardiovascular function may be enhanced through the new depurinized milk diet, which may improve cardiovascular system function via increased bone marrow stem cell regenerative potential, decreased plasma oxidative stress parameters, and decreased levels of myocardial damage markers and cholesterol. New dairy technology strategies focused on eliminating harmful milk compounds should be completely nontoxic. Novel milk products should be tested for their ability to improve tissue repair and function.     

Integration and management of renewables into Total Sites with variable supply and demand

Reducing CO₂ emissions could be achieved by maximising heat recovery and increasing the share of renewables in the primary energy mix. Process Integration has developed over the years into a credible process system engineering tool. One of its important developments has been Total Site Heat Integration, which has combined the heating and cooling requirements of individual processes unlocking, allowing better integration. The current paper presents an extension of the Total Site methodology covering industrial, residential, service, business and agricultural customers and the incorporation of renewable energy sources (solar, wind, biomass, and some types of waste), accounting for the often substantial variability on the supply and demand sides and for the use of non-isothermal utilities. It further applies the extension of the heat cascade principle with inclusion of heat storage and minimises the heat waste and carbon footprint of the considered sites. This is illustrated with a comprehensive case study.     

Poly(ethoxytriethyleneglycol acrylate) cryogels as novel sustained drug release systems for oral application

Novel temperature sensitive cryogels of poly(ethoxytriethyleneglycol acrylate) (PETEGA), with in situ entrapped active substance, are synthesized employing the UV irradiation technique and tested as matrix for controlled release of the hydrophilic drug verapamil hydrochloride. PETEGA cryogels are non-toxic materials and, due to the macroporous structure, exhibit a reversible, ultra-rapid volume phase transition at temperature ca. 31 °C. Carriers based on PETEGA cryogels possess sustained release of verapamil hydrochloride over a period of more than 8 h, which is attributed to the hydrophobic state of the polymer network at physiological temperature and the method of drug immobilization. Drug release characteristics of PETEGA cryogels are compared with another cryogel systems, based on polyacrylamide (PAAm), poly(N-isopropylacrylamide) (PNIPAAm) and poly(2-hydroxyethyl methacrylate) (PHEMA), obtained via the same method.     

Effect of structural and acidity/basicity changes of CuO–CeO2 catalysts on their activity for water–gas shift reaction

The objective of this work was to investigate the influence of CuO loading and catalyst pretreatment procedure to derive an optimal CuO–CeO₂ catalyst for the water–gas shift reaction (WGS), and to study in detail structure– and surface acidity–activity relationships. Catalyst samples prepared by coprecipitation and a 10, 15 and 20 mol% CuO content were examined by XRD, BET and TPR/TPD analyses and subjected to pulse WGS activity tests in the temperature range of 180–400 °C. Strong structure–activity dependence in the WGS reaction was observed for all catalyst samples. It was established that increasing CuO content has a positive effect on H₂ production during the WGS reaction, due to favored CeO₂ reduction. Increasing calcination temperature on the other hand reduces the BET surface area, induced by CuO sintering and agglomeration of CeO₂ particles, resulting in a negative effect on H₂ production. Distinctive WGS activity dependence on surface acidity was observed and investigated.