Synthesis of hydrogels by polymerization of itaconic acid–choline chloride deep eutectic solvent

Itaconic acid (IA)–choline chloride (CC) deep eutectic solvents (DES) were prepared and characterized by NMR, TGA, and DSC. Poly(itaconic acid–co–bisacrylamide) hydrogels were synthesized by in situ polymerization‐crosslinking of the DES. For comparison, the hydrogels were also prepared in water under the same process conditions, that is, temperature, time, initial concentration of the monomer, the initiator, and N,N′‐methylenebisacrylamide (BAA) as the cross‐linking agent. Chemical structure of the polymers was proved by elemental analysis and FTIR. The values of insoluble gel fraction and water swelling of obtained hydrogels suggest that polymers prepared in DES have higher cross‐link density. Preliminary comparative studies of polymerization of IA in water and in DES medium indicated higher polymerization rate resulting from the presence of the choline salt, what might explain properties of the hydrogels prepared in DES. This study shows that DES can be used both as a solvent and catalyst in free‐radical polymerization processes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40608.     

Designing of low-power data oriented adders

The paper presents an idea of designing of low-power adders addressed to specific data processing. Mainly, the idea consists in proper choosing of 1-bit full adder cells for given probability of summed data, to obtain reduction in consumed power. Additionally different structures of the cells can be used, in one design, if it leads to reduction of power dissipation. To proper choice of structures of 1-bit full adders theirs energy characteristic versus summed data is needed. So, at the beginning we present results of assessment of a few 1-bit adder cells selected from literature and designed in UMC180 CMOS technology. The extended model of power consumption, taking into consideration input vector changes, was used, giving more accurate values than traditional model based on switching activity only. Thanks to the use of this model, obtained results allow detailed analysis of 1-bit adders on account of the using them in designing of low-power multi-bit adders summing specific data. Based on the results of analyses and given characteristic of summed data, appropriate full adder cells can be chosen to the final design of low-power data oriented adder. In specific case, cells which are made in different techniques can be used in multi-bit adder. A few examples are shown at the end of the paper.     

NaCl-Induced Elicitation Alters Physiology and Increases Accumulation of Phenolic Compounds in Melissa officinalis L.

In nature, plants usually produce secondary metabolites as a defense mechanism against environmental stresses. Different stresses determine the chemical diversity of plant-specialized metabolism products. In this study, we applied an abiotic elicitor, i.e., NaCl, to enhance the biosynthesis and accumulation of phenolic secondary metabolites in Melissa officinalis L. Plants were subjected to salt stress treatment by application of NaCl solutions (0, 50, or 100 mM) to the pots. Generally, the NaCl treatments were found to inhibit the growth of plants, simultaneously enhancing the accumulation of phenolic compounds (total phenolics, soluble flavonols, anthocyanins, phenolic acids), especially at 100 mM NaCl. However, the salt stress did not disturb the accumulation of photosynthetic pigments and proper functioning of the PS II photosystem. Therefore, the proposed method of elicitation represents a convenient alternative to cell suspension or hydroponic techniques as it is easier and cheaper with simple application in lemon balm pot cultivation. The improvement of lemon balm quality by NaCl elicitation can potentially increase the level of health-promoting phytochemicals and the bioactivity of low-processed herbal products.     

The application of Langmuir–Blodgett technique in preparation of the macroporous titania coatings

The aim of this work was preparation of the macroporous titania coatings with the use of the sol–gel process and poly(methylmetacrylate) beads as a template. The effectiveness of the Langmuir–Blodgett (LB) and dip-coating (DC) methods in deposition of polymer beads on the silicon wafers was compared. Resulted polymer layers and final porous titania coatings were analyzed with the use of the atomic force microscope. It was found, that application of the LB is possible only when arachidic acid is present in the subphase. It should be highlighted, that the application of the LB method is the novelty between the methods of the polymer beads arrangement having the diameter of 200–300 nm. Main factors which influence the structure and the arrangement of polymer templates were the concentration of the polymer suspension and the rate of the substrate immersion/withdrawal from the suspension. We established, that the optimal concentrations for preparation of polymer templates, exhibiting good arrangement of individual beads, were 0.5 and 6 % for LB and DC methods, respectively. The size of pores of the obtained macroporous titania (200–330 nm) corresponds well with the size of the polymer beads used as the template (200–235 nm).     

Simultaneous Heat and Mass Transfer in Shrinkable Apple Slab During Drying

The goal of the study was to determine the influence of drying shrinkage on the kinetics of convection apple slab drying. The arbitrary Lagrange-Eulerian (ALE) method was used to enter a problem with moving boundaries. It was found that drying shrinkage had a major influence on the both simulated temperature and water content in the material. The lower the moisture content in particles during drying, the more pronounced the effect of shrinkage on simulation of heat and mass transfer. It was found that application of the arbitrary Lagrange-Eulerian method for shrinkage modeling leads to a relatively simple mathematical model of the drying kinetics of shrinkable materials.     

Cluster-based instance selection for machine classification

Instance selection in the supervised machine learning, often referred to as the data reduction, aims at deciding which instances from the training set should be retained for further use during the learning process. Instance selection can result in increased capabilities and generalization properties of the learning model, shorter time of the learning process, or it can help in scaling up to large data sources. The paper proposes a cluster-based instance selection approach with the learning process executed by the team of agents and discusses its four variants. The basic assumption is that instance selection is carried out after the training data have been grouped into clusters. To validate the proposed approach and to investigate the influence of the clustering method used on the quality of the classification, the computational experiment has been carried out.     

Carbon Monoxide Oxidation over Au/Ce1−x Zr x O2 Catalysts: Effects of Moisture Content in the Reactant Gas and Catalyst Pretreatment

The Au/Ce_1?x Zr _x O₂ (x = 0, 0.25, 1) catalysts were synthesized, characterized by BET, XRD, TPR-H₂, HRTEM, AAS and tested in CO oxidation. The effect of moisture in the reactant gas on CO conversion has been studied in a wide range of concentrations (~0.7–6000 ppm). Moisture generates a positive effect on catalytic activity and wet conditions gave higher CO conversions. The optimum concentration of moisture for CO oxidation over Au/CeO₂ and Au/Ce_0.75Zr_0.25O₂ is 200–1000 ppm, while further increase in the moisture content suppresses CO conversion. The activity of the studied Au catalysts depends on the amount of moisture adsorbed on the catalyst rather than on its content in the feed stream, which suggests that the reaction involves water-derived species on the catalysts surface. The effect of the catalysts pretreatment in air, dry He, H₂ stream as well as H₂ + H₂O gas mixture on their catalytic performance in CO oxidation has been also investigated. The model of the active sites for CO oxidation over the studied catalysts was proposed.