Modelling and performance evaluation of chromatographic monosaccharide recovery from concentrated acid lignocellulosic hydrolysates

BACKGROUND: Chromatographic fractionation of concentrated acid lignocellulosic hydrolysates was investigated. The goal was to present a model that can be used in designing and performance evaluation of the fractionation process. Simple models were fitted to the experimental sorption data of the main components of the hydrolysates (sulfuric acid, monosaccharides, and acetic acid) on CS16GC resin. A column model which takes into account resin shrinking was derived. RESULTS: Simulation results were found to be in good agreement with the experimental results. The isotherm models predicted correctly the co‐operative effect of H₂SO₄ on the sorption of the other adsorbates. The effect of column loading on the productivity of the separation process was studied with simulations. With 20 wt% H₂SO₄, the highest productivity was obtained with 11.5 vol% column loading. In addition, a process consisting of concentrated acid lignocellulose hydrolysis, batchwise chromatographic separation, and H₂SO₄ recycling was investigated. With the recycling, the maximum productivity was obtained with 18.2 vol% column loading. CONCLUSIONS: It was demonstrated that the entire reactor‐separation process with internal recycling must be considered when evaluating the performance of the monosaccharide‐acid separation step. Process performance was found to decrease with increasing feed concentration of sulfuric acid. Copyright © 2012 Society of Chemical Industry     

Morphological Family Size in a Morphologically Rich Language: The Case of Finnish Compared With Dutch and Hebrew.

Finnish has a very productive morphology in which a stem can give rise to several thousand words. This study presents a visual lexical decision experiment addressing the processing consequences of the huge productivity of Finnish morphology. The authors observed that in Finnish words with larger morphological families elicited shorter response latencies. However, in contrast to Dutch and Hebrew, it is not the complete morphological family of a complex Finnish word that codetermines response latencies but only the subset of words directly derived from the complex word itself. Comparisons with parallel experiments using translation equivalents in Dutch and Hebrew showed substantial cross-language predictivity of family size between Finnish and Dutch but not between Finnish and Hebrew, reflecting the different ways in which the Hebrew and Finnish morphological systems contribute to the semantic organization of concepts in the mental lexicon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of Substituted 1,2,3‐Dithiazoles as Inhibitors of the Feline Immunodeficiency Virus (FIV) Nucleocapsid Protein via a Proposed Zinc Ejection Mechanism

A diverse library of 5‐thieno‐, 5‐oxo‐, and 5‐imino‐1,2,3‐dithiazole derivatives was synthesized and evaluated for efficacy against the feline immunodeficiency virus (FIV) as a model for HIV in cells. Several diverse compounds from this series displayed nanomolar activity and low toxicity, representing a potential new class of compounds for the treatment of FIV and HIV.     

Treatment of PAH‐contaminated soil by combination of Fenton's reaction and biodegradation

A combination of modified Fenton and biological treatment was used to remove polycyclic aromatic hydrocarbons (PAHs) from creosote oil‐contaminated soil. After modified Fenton reaction the toxicity of column leachate and soil to Vibrio fischeri increased. The number of intact bacterial cells and utilisation of PAHs in PAH utilisation microplate assay decreased after modified Fenton reaction. However, bacteria in chemically treated soil utilised PAHs without addition of other carbon sources. The activity of extracellular esterases increased during incubation of modified Fenton‐treated soil. PAH removal in combined chemical oxidation and incubation (43–59%) was higher than in incubation alone (22–30%). Residual H₂O₂ in soil allowed chemical oxidation of PAHs during incubation. Copyright © 2006 Society of Chemical Industry     

Preparation of Ni/Al2O3 catalysts from vapor phase by atomic layer epitaxy

Ni/Al₂O₃ catalysts were prepared by saturating gas-solid reactions as an atomic layer epitaxy (ALE) process. Vaporized Ni(acac)₂ was chemisorbed on a porous alumina support, and the produced surface complex was then air treated to remove the ligand residues. The nickel content could be precisely controlled by repeating this reactor cycle. On alumina preheated at 800°C, the nickel content varied from 3 to 21 wt%, when the number of reaction cycles was increased from one to ten. The performance of the Ni-catalysts was evaluated in the gas-phase hydrogenation of toluene. The preheat temperature of alumina influenced the activity of the catalyst, and a maximum in the activity was observed for catalysts prepared from alumina preheated at 875°C. Catalysts prepared by four reaction cycles, containing about 10 wt% nickel, gave the highest utilization of nickel.     

The structure of E.coli soluble inorganic pyrophosphatase at 2.7 A resolution

Due to retyping the authors' names when transferring correctionsat the first proof stage, a typographical error was introduced.The correct spelling of the authors' names appears above.     

Rapid synthesis of nanostructured porous silicon carbide from biogenic silica

Nanostructured silicon carbide (SiC) is an exceptional material with numerous applications, for example, in catalysis, biomedicine, high-performance composites, and sensing. In this study, a fast and scalable method of producing nanostructured SiC from plant materials by magnesiothermic reduction via self-propagating high-temperature synthesis (SHS) route was developed. The produced biogenic material possessed a high surface area above 200 m²/g with a SiC crystallite size below 10 nm, which has not been done previously by SHS. This method enables affordable synthesis of the material plant-based precursors in a reaction that only takes a few seconds, thereby paving a way for nanostructured SiC production in high volumes using renewable resources. The material was also functionalized with carboxylic acid and bisphosphonate moieties, and its use as metal adsorbent in applications such as wastewater remediation was demonstrated.     

The structure of E.coli soluble inorganic pyrophosphatase at 2.7 A resolution

Hie structure of E.coli soluble inorganic pyrophosphatase hasbeen refined at 2.7 resolution to an R-factor of 20.9. Theoverall fold of the molecule is essentially the same as yeastpyrophosphatase, except that yeast pyrophosphatase is longerat both the N- and C-termini. Escherichia coli pyrophosphataseis a mixed +ß protein with a complicated topology.The active site cavity, which is also very similar to the yeastenzyme, is formed by seven ß-strands and an -helixand has a rather asymmetric distribution of charged residues.Our structure-based alignment extends and improves upon earliersequence alignment studies; it shows that probably no more than14, not 15–17 charged and polar residues are part of theconserved enzyme mechanism of pyrophosphatases. Six of theseconserved residues, at the bottom of the active site cavity,form a tight group centred on Asp70 and probably bind the twoessential Mg⁺ ions. The others, more spreadout and more positivelycharged, presumably bind substrate. Escherichia coli pyrophosphatasehas an extra aspartate residue in the active site cavity, whichmay explain why the two enzymes bind divalent cation differently.Based on the structure, we have identified a sequence motifthat seems to occur only in soluble inorganic pyrophosphatases.     

Narrow linewidth templates for nanoimprint lithography utilizing conformal deposition

Nanoimprint lithography has the potential to cost efficiently realize patterns with extremely narrow linewidth over a large area. A significant challenge to achieving this target is the fabrication of nanoimprint templates. The cost and writing time of conventional electron beam lithography for direct writing of the templates rapidly increases as the patterned area increases and the linewidth decreases. We have developed a novel process for creating narrow linewidth nanopatterns. This process is based on conformal deposition of thin films on seed nanopatterns. We have demonstrated the process by fabricating nanosized loops and lines. The linewidth of the structures can be tuned precisely, and in our experiments it could be reduced to 20?nm. The closed loop structures are interesting, since this geometry is crucially important in many leading edge research fields such as negative refractive index materials, ultrahigh density memory applications and quantum rings. The fabricated template was subsequently used as a template in soft-stamp UV nanoimprint lithography to successfully replicate the structures in UV-curable resist.