Azo and azoxythiacrown ethers: synthesis and properties

A series of 16- and 18-membered azo- and azoxythiacrown ethers have been synthesized by reductive macrocyclization of the respective bis(nitrophenoxy)oxaalkanes. The aromatic residues located in the polyether region of the molecule were introduced to macrocyclic skeletons and their affinities toward different groups of metal cations in ion-selective electrodes were described. X-ray structures for one dinitropodand and one azoxybenzothiacrown exhibiting strong π–π and π–H interactions have been found.     

Physical and Sensory Properties of Japanese Quince Chips Obtained by Osmotic Dehydration in Fruit Juice Concentrates and Hybrid Drying

Japanese quince has high health value, but due to its taste and texture, it is difficult to eat raw. The use of innovative drying methods to produce dried snack foods from these fruits may be of interest to producers and consumers. The physicochemical and sensory properties of 3 mm slices of Japanese quince fruit (with skin, without seeds) obtained by osmotic pre-treatment in chokeberry and apple juice concentrates, and with the use of convection (convective drying, C-D), freeze-drying (F-D), and convection-microwave-vacuum drying (hybrid) are assessed. The methods of drying osmo-dehydrated slices do not affect the dry matter content. In most dried quince, the water activity is 0.40 or lower. Pre-osmotic dehydration and drying have a significant impact on the mechanical and acoustic properties of quince chips. Sensory attractive chips emit loud acoustic emission (AE) during the breaking test. Chips that are osmo-dehydrated in a mixture of chokeberry juice concentrate and sucrose and dried by a hybrid method are attractive. They have a dark red color given by chokeberry concentrate and a slight sweet (with a slight sour-bitter) taste. The sensory evaluation was useful for determining the quality of the chips in terms of their texture (crispness) tested by mechanical methods. Their sensory ratings (overall desirability as weight of color, taste, crispness, and flavor) are high and similar (from 3.8 to 4.1). The use of innovative drying methods with pre-osmotic treatment allows obtaining dried material with properties comparable to those obtained by the F-D method, but in a much shorter time, i.e., with lower energy and using a simple method.     

Emission Characteristics of the D.C., 100 kHz and 13.5 MHz Hollow Cathode Discharges

Hollow cathode discharges in argon at various pressures and currents have been studied by optical emission spectroscopy. The cathodes were made of copper, bronze and brass. The discharges were supplied by direct, 100 kHz and 13.5 MHz currents. Atomic and ionic spectra of plasma gas and elements of cathode materials and molecular bands of ZnH and PN formed due chemical reactions between plasma components have been excited and measured. Relations between emission intensities, excitation temperatures and discharge conditions have been analysed and discussed.     

Effective Purification of Cerrena unicolor Laccase Using Microfiltration, Ultrafiltration and Acetone Precipitation

Microfiltration followed by concentration and diafiltration on ultrafiltration membranes (Biomax-100, Biomax-10 and Ultracel-10) was used to recover extracellular laccase (EC 1.10.3.2) from culture broth of wood-rotting fungus Cerrena unicolor. Feed, permeate, retentate and membrane wash-out solutions were analysed for the presence of laccase, proteases, protein and brown impurities. An easy, cheap and short-term procedure was proposed to obtain retentates with low yields of total proteins (less than 14%), proteases activity (less than 15%) and brown impurities (from 2% to 29%) with a simultaneous laccase recovery above 73%. The degree of laccase purification varied from 6.7 to 11.0 and depended on the type of membrane used and content of brown pigments in the feed. Subsequent protein precipitation with cold acetone increased the degree of purification about twice and reduced proteases and brown impurities to some extent. Ultracel-10 membrane was recommended as the best solution to prevent fouling of membranes and to obtain laccase-enriched fraction with a very low content of proteases and brown pigments.     

Comparison of Calculated Values of the Lipophilicity of 2,6-Disubstituted 7-Methylpurines with Values Determined by RPTLC

JPC – Journal of Planar Chromatography – Modern TLC - The lipophilicity of 2,6-disubstituted 7-methylpurines and 6-mer-captopurine has been determined by reversed-phase thin-layer...     

The Effect of Metal Salts on the Separation of Carbohydrates by TLC

JPC – Journal of Planar Chromatography – Modern TLC - Carbohydrates have been examined by TLC on layers modified with metal ions, in the form of salts, by dipping commercial plates in...     

From vicious to virtuous circles: problem structuring for quantified decision making in operationalization of corporate social responsibility

There is no formalised approach for problem structuring and quantitative decision support to operationalise corporate social responsibility (CSR) implementation. In this paper, techniques for considering criteria relationships are outlined and a holistic, systematic framework combining a qualitative and quantitative method for practical CSR integration is provided. Cognitive mapping (CM) is applied to structure the problem picture, and the cause–effect relationships between decision elements. Soft CM methodology is employed to assess the cross-criteria interactions, at both an individual and a collective level. The interactions of criteria can have a significant impact upon CSR implementation. Such impacts can be direct or indirect through their close linkages to other criteria. The causal strategic map serves as an input to the analytic network process (ANP) to carry out the multi-criteria decision analysis. Then, CM and ANP are applied in a comparative analysis to verify whether the measures of criteria significance do correspond. The key criteria in networks are identified using centrality in CM and single limited priorities in ANP. This study demonstrates that using criteria without considering their interactions will result in shortcomings in the evaluation and assessment of CSR programmes. The holistic framework, combining CM and ANP proposed in this work, enhances the process of problem structuring and supports preference-based evaluation of decision alternatives. The results of our study yield that the mapping procedure has an influence on the criteria significance in networks. The correspondence between CM and ANP is stronger when cause relationships are rigidly interpreted. More unambiguous interpretations of causal relations can be achieved if methods are used jointly and common peaks of importance in both CM and ANP could potentially serve as indications of key decision elements.