Polystyrene Containing Carbinolamine/Azomethine Potentially Useful as Antimicrobial Agent: Synthesis and Biological Evaluation

An investigation of antimicrobial properties of 12 novel modified polymer derived from the condensation reaction of (aminomethyl)polystyrene and four substitute salicylaldehyde (2-hydroxy benzaldehyde, 5-fluoro-2 hydroxy benzaldehyde, 5-fluoro-3-chloro-salicylaldehyde and 5-fluoro-3-methyl-salicylaldehyde) has been carried out and Cr(III) and Ni(II) complexes have been prepared. Modified polymers were characterized by magnetic susceptibility, elemental analyses, and spectral studies. The ¹H NMR and ¹³C NMR spectra analysis of the polymeric carbinolamine/azomethine were determined. In addition, surface morphology and composition were determined by SEM/EDX. Thermo gravimetric analyses of polymers were carried out in nitrogen atmosphere. Antibacterial activities of the polymers attached carbinolamine/azomethine and their complexes were studied by the well-diffusion method against Listeria monocytogenes 4b, Staphylococcus aureus, Escherichia coli, Salmonella typhi H, Brucella abortus, Staphylococcus epidermis sp., Micrococcus luteus, Shigella dysenteria type 10, Bacillus cereus, Pseudomonas putida and antifungal activity against Candida albicans.     

Carrot cropping on organic soil is a hotspot for nitrous oxide emissions

The emissions of the greenhouse gas nitrous oxide (N₂O) were measured from a non nitrogen fertilized carrot (Daucus carota ssp. sativa) field on an organic soil in Sweden during one cropping and post-harvest season. The cumulative emission during the measuring period of 149?days was 41 (±2.8) kg N₂O ha^?1. Dividing the measuring period into a cropping and a post-harvest period revealed that the presence of carrots strongly stimulated N₂O emissions, as the emission during the cropping period was one order of magnitude higher compared to the post-harvest period. The N₂O emission from the carrot field were higher than fluxes reported from cereal crop and grass production, but in the same order as reported fluxes from vegetable cropping on organic soils. In conclusion, our results indicate that the cultivation of root vegetable, such as carrots, on organic soil can be a high point source for N₂O emissions.     

Hydration of Saccharides: Estimation of Reaction Properties and Equilibrium Conversion

Biomass holds great promise as a renewable source of hydrogen and thus as a zero‐emission, carbon‐neutral, and nearly inexhaustible energy resource. Thermodynamic analysis of biomass hydration is carried out to study the reaction properties considering a series of saccharides as a model. Equilibrium constants and composition are estimated in dependence on the saccharide chain length and temperature. The latter is also studied as a function of the reactant ratios and in the presence of nonreacting additives. Being highly endothermic, the reaction is thermodynamically favorable due to a high entropic contribution. Increase in the saccharide chain length affects the conversion only slightly, so the results for low‐molecular‐weight saccharides can be transferred to long‐chain ones.     

Reaction Mechanism and Kinetics of 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene and Carbon Dioxide in Alkanol Solutions

Carbon dioxide‐binding organic liquids (CO₂BOL) are a new class of solvents with advantageous properties such as high boiling points, low specific heats, high absorption capacities, and easily reversible reactions. In order to implement these solvents in processes, the reaction characteristics must be determined a priori. This work presents an analysis of the rate constants and activation energies of the reaction between carbon dioxide and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in 1‐hexanol and 1‐propanol. The reactions were found to comply with a termolecular reaction mechanism and exhibited pseudo‐first‐order behavior in the presence of excess DBU and 1‐alkanol. It was concluded that DBU‐based CO₂BOL are environmentally friendly and easy‐to‐handle solvents that may provide great flexibility and improvements over conventional carbon dioxide absorption processes.     

Post‐protection effect of heat‐resistant insulations on timber‐frame members exposed to fire

In lightweight walls and floors, the load‐bearing timber members are protected by cladding on the sides to form a divider between two fire compartments or to provide appropriate fire protection to the load‐bearing members. The spaces between the timber members can be void or filled with insulation materials. Although a huge number of different insulation materials exist, the most commonly used material is mineral wool insulation. The existing design model for glass wool‐insulated timber‐frame constructions, given in European standard 1995‐1‐2, assumes collapse of the glass wool after failure of the cladding. However, a new form of glass wool insulation, suitable for use at high maximum service temperatures, is now available in the market. The charring phase after the cladding's failure is known as the post‐protection phase. The behaviour of the new heat‐resistant glass wool in the post‐protection phase is similar to that of stone wool and considerably better than that of traditional glass wool. The protective properties of stone wool have changed over the last decades. Charring is one of the main parameters needed to calculate the resistance of a structure to fire. Based on experimental investigations, this paper describes the analysis of the effect of the insulation with regard to its ability to protect timber members against charring during the post‐protection phase. Copyright © 2011 John Wiley & Sons, Ltd.     

Numerical simulation of particulate processes for control and estimation by spectral methods

Results of application of pseudospectral methods, also known as spectral collocation methods, to practical particulate processes including growth, nucleation, aggregation, and breakage are presented. For growth‐dominated processes, a considerable reduction in model dimension can be achieved; for pure aggregation and breakage they form a viable option. To handle problems that include aggregation, breakage, and growth phenomena simultaneously, we introduce a hybrid algorithm combining the advantages of spectral methods and cell average or fixed pivot methods for aggregation and breakage. Results are shown for analytical examples as well as real processes taken from the fields of granulation and crystallization. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2309–2319, 2012     

Design of Cyclic Peptides Featuring Proline Predominantly in the cis Conformation under Physiological Conditions

Turns are secondary‐structure elements that are omnipresent in natively folded polypeptide chains. A large variety of four‐residue β‐turns exist, which differ mainly in the backbone dihedral angle values of the two central residues i+1 and i+2. The βVI‐type turns are of particular biological interest because the i+2 residue is always a proline in the cis conformation and might thus serve as target of peptidyl prolyl cis/trans isomerases (PPIases). We have designed cyclic hexapeptides containing two proline residues that predominantly adopt the cis conformation in aqueous solution. NMR data and MD calculations indicated that the cyclic peptide sequences c‐(‐D Xaa‐Ser‐Pro‐D Xaa‐Lys‐Pro‐) result in highly symmetric backbone structures when both prolines are in the cis conformation and the D ‐amino acids are either alanine or phenylalanine residues. Replacement of the serine residue either by phosphoserine or by tyrosine compromises this symmetry, but further increases the cis conformation content of both prolines. As a result, we obtained a cyclic hexapeptide that exists almost exclusively as the cis‐Pro/cis‐Pro conformer but shows no cis/trans interconversion even in the presence of the PPIase Pin1, apparently due to an energetically quite favorable but highly restricted conformational space.     

Sulfite Action in Glycolytic Inhibition: In Vivo Real‐Time Observation by Hyperpolarized 13C NMR Spectroscopy

Detecting the molecular targets of xenobiotic substances in vivo poses a considerable analytical challenge. Here, we describe the use of an NMR‐based tracer methodology for the instantaneous in vivo observation of sulfur(IV) action on cellular metabolism. Specifically, we find that glycolytic flux is directed towards sulfite adducts of dihydroxyacetone phosphate and pyruvate as off‐pathway intermediates that obstruct glycolytic flux. In particular, the pyruvate–sulfite association hinders the formation of downstream metabolites. The apparent in vivo association constant of pyruvate and sulfite agrees with the apparent inhibition constant of CO₂ formation, thus supporting the importance of pyruvate interception in disturbing central metabolism and inhibiting NAD regeneration.     

The effects of achromatic and chromatic color schemes on participants' task performance in and appraisals of an office environment

This study explores the effects of chroma on participants' performance and environmental appraisal of an office. The research was conducted in a full‐scale experimental room designed as a private office where achromatic and chromatic color schemes with coequal values were applied. Sixty participants were assigned tasks and given a questionnaire to appraise the spatial color schemes. The findings show that chroma significantly affects performance and space appraisal. In terms of accuracy and time spent performance scores measured significantly better in the room with the chromatic scheme than those in the room with the achromatic scheme. The office with the chromatic scheme was found to be more pleasant, attractive, satisfying and dynamic than the one with the achromatic scheme, whereas the achromatic scheme was thought to be more formal and harmonious. Categorization of pleasantness, harmony, dynamism and spaciousness by factor analysis also showed differences between the achromatic and chromatic schemes. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2012     

Dyeing properties of textiles by Turkish hazelnut (Corylus colurna): leaves,coat, shell and dice

Turkey has a great number of hazelnut trees that possess nutritious components. However, only the inside part of the hazelnut is used as a nutrient, while the rest of it is waste. This study suggests that the waste parts of the Turkish hazelnut could be used as a natural dye for dyeing textile fabrics. The dyeing properties of the leaves, coat, shell and dice of the hazelnut were studied on wool, cotton and viscose fabric by using three different mordants: copper sulphate, iron sulphate and aluminium sulphate. The selected dyed fibre sample surfaces were observed using a scanning electron microscope. The colour strength (K/S), light, washing, rubbing, and perspiration fastness levels of the dyed fabrics were investigated. The experimental natural dyeing results indicate that waste hazelnut‐based products can be used as a natural dye for textile coloration.