735 research outputs found
New Approaches to Minimum-Energy Design of Integer- and Fractional-Order Perfect Control Algorithms
In this paper the new methods concerning the energy-based minimization of the perfect control inputs is presented. For that reason the multivariable integer- and fractional-order models are applied which can be used for describing a various real world processes. Up to now, the classical approaches have been used in forms of minimum-norm/least squares inverses. Notwithstanding, the above-mentioned tool do not guarantee the optimal control corresponding to optimal input energy. Therefore the new class of inversebased methods has been introduced, in particular the new σ- and H-inverse of nonsquare parameter and polynomial matrices. Thus a proposed solution remarkably outperforms the typical ones in systems where the control runs can be understood in terms of different physical quantities, for example heat and mass transfer, electricity etc. A simulation study performed in Matlab/Simulink environment confirms the big potential of the new energy-based approaches
Dual Stimuli-Responsive Polysaccharide Hydrogels Manufactured by Radiation Technique
Featured Application Stimuli-responsive hydrogels encompassing biobased polymers are anticipated for utilization in various fields, starting from drug delivery systems through temporal actuators and water reservoirs to biodegradable microelements and nutrient delivery depots. This paper describes the results of the radiation-induced crosslinking of polysaccharides modified with hydroxypropyl and carboxymethyl functional groups, hydroxypropylcellulose (HPC) and carboxymethylcellulose (CMC), respectively, without and with poly(ethylene glycol) diacrylate (PEGDA) as a crosslinking agent, to obtain dual stimuli-responsive hydrogels. The gels were characterized in terms of water uptake and gel fraction, parameters that mainly depend on the HPC-CMC compositions, but also on the macromer crosslinker content and the absorbed dose. The swelling of hydrogels is controlled by both the temperature, due to the amphiphilic character of HPC and pH, due to the anionic functional groups of CMC. In spite of a similar degree of substitution in both cellulose derivatives, 1.4 for HPC and 1.2 for CMC, the pH response of hydrogels with an equal content of both polysaccharides is considerably higher-a reduction in swelling of up to 95% with a decrease in the pH to 2 was recorded-than the response to thermal-stimulus-wherein a reduction in swelling of less than 70% with an increasing in temperature to 55 degrees C was found. These biopolymers-based hydrogels of specific, stimuli-responsive swelling properties are anticipated in applications where a combination of two stimuli is essential and biodegradation may be required
Acetylcholinesterase, Tyrosinase, α-Glucosidase inhibition by Ammodaucus leucotrichus Coss. & Dur. Fruits Essential oil and Ethanolic Extract and Molecular Docking Analysis
Medicinal and aromatic plants serve as valuable reservoirs of bioactive molecules and mineral compounds that are harnessed for therapeutic and agro-food applications. The objective of this study was to assess the inhibitory enzyme properties of Ammodaucus leucotrichus Coss & Dur fruit essential oil, as well as its aqueous and ethanol extracts, against acetylcholinesterase, tyrosinase, and α-glucosidase. Additionally, the antioxidant activity of these natural mixtures was evaluated using three different methods: DPPH, FRAP, and β-carotene bleaching tests. Furthermore, this research endeavors to examine the mineral constituents of various components of the plant under investigation. The various natural combinations that were examined exhibited a notable inhibitory impact on the enzymes acetylcholinesterase (67.56-92.30%), tyrosinase (57.52-63.44%), and α-glucosidase (61.22-72.49%). The analyzed extracts also demonstrate a significant antioxidant activity. Furthermore, the results obtained from the analysis indicate a notable presence of both macro and microelements, such as calcium (2.028 mg/g for leaves and 1.787 mg/g for fruits), within the Ammodaucus leucotrichus Coss & Dur plant. The current study supports the significance of utilizing Ammodaucus leucotrichus Coss & Dur fruits in the medicinal and agro-alimentary sectors. The utilization of molecular docking techniques was employed in order to make predictions regarding the therapeutic effects of Ammodaucus leucotrichus Coss & Dur fruits
Analysis of ground-based Rn-222 measurements over Spain: filling the gap in southwestern Europe
Harmonized atmospheric 222Rn observations are required by the scientific community: these data have been lacking in southern Europe. We report on three recently established ground-based atmospheric 222Rn monitoring stations in Spain. We characterize the variability of atmospheric 222Rn concentrations at each of these stations in relation to source strengths, local, and regional atmospheric processes. For the study, measured atmospheric 222Rn concentrations, estimated 222Rn fluxes, and regional footprint analysis have been used. In addition, the atmospheric radon monitor operating at each station has been compared to a 222Rn progeny monitor. Annual means of 222Rn concentrations at Gredos (GIC3), Delta de l'Ebre (DEC3), and Huelva (UHU) stations were 17.3¿±¿2.0¿Bq¿m-3, 5.8¿±¿0.8¿Bq¿m-3, and 5.1¿±¿0.7¿Bq¿m-3, respectively. The GIC3 station showed high 222Rn concentration differences during the day and by seasons. The coastal station DEC3 presented background concentrations typical of the region, except when inland 222Rn-rich air masses are transported into the deltaic area. The highest 222Rn concentrations at UHU station were observed when local recirculation facilitates accumulation of 222Rn from nearby source represented by phosphogypsum piles. Results of the comparison performed between monitors revealed that the performance of the direct radon monitor is not affected by meteorological conditions, whereas the 222Rn progeny monitor seems to underestimate 222Rn concentrations under saturated atmospheric conditions. Initial findings indicate that the monitor responses seem to be in agreement for unsaturated atmospheric conditions but a further long-term comparison study will be needed to confirm this result.Peer ReviewedPostprint (published version
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