COMPUTER-AIDED ANALYSIS AND DESIGN OF AN ATP REGENERATION REACTOR

The two coupled reactions catalyzed by the enzymes adenylate kinase and acetate kinase for the regeneration of ATP from AMP in a CSTR were analyzed to obtain information required for the design of such a reactor. Unconventional but efficient computational methods were developed to handle the difficulty associated with the extremely complex rate expressions involved.     

Replacing fossil oil with fresh oil – with what and for what?

Industrial chemicals and materials are currently derived mainly from fossil‐based raw materials, which are declining in availability, increasing in price and are a major source of undesirable greenhouse gas emissions. Plant oils have the potential to provide functionally equivalent, renewable and environmentally friendly replacements for these finite fossil‐based raw materials, provided that their composition can be matched to end‐use requirements, and that they can be produced on sufficient scale to meet current and growing industrial demands. Replacement of 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met, will require a trebling of global plant oil production from current levels of around 139 MT to over 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (i) tailor plant oils to have high purity (preferably >90%) of single desirable fatty acids, (ii) introduce unusual fatty acids that have specialty end‐use functionalities and (iii) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. This review outlines recent progress and future challenges in each of these areas. Practical applications: The research reviewed in this paper aims to develop metabolic engineering technologies to radically increase the yield and alter the fatty acid composition of plant oils and enable the development of new and more productive oil crops that can serve as renewable sources of industrial feedstocks currently provided by non‐renewable and polluting fossil‐based resources. As a result of recent and anticipated research developments we can expect to see significant enhancements in quality and productivity of oil crops over the coming decades. This should generate the technologies needed to support increasing plant oil production into the future, hopefully of sufficient magnitude to provide a major supply of renewable plant oils for the industrial economy without encroaching on the higher priority demand for food oils. Achievement of this goal will make a significant contribution to moving to a sustainable carbon‐neutral industrial society with lower emissions of carbon dioxide to the atmosphere and reduced environmental impact as a result.     

Fire‐retardant poly(ethylene terephthalate) by combination of expandable graphite and layered clays for plastics and textiles

Expandable graphite (EG) and polyethylene terephthalate (PET) were melt blended to develop a new nanocomposite intumescent flame retardant in which the effect of combination of EG with nanoclays would be exploited with sodium and organo‐modified montmorillonites, namely Cloisite^®Na, Cloisite^®10A and Cloisite^®30B. X‐ray diffraction analysis coupled to transmission electron microscopy and rheology shows that PET–EG–clay compounds are characterized by an exfoliated and/or intercalated morphology as a function of the type of clay. Thermal stability of composites is enhanced in nitrogen and air by filler adding as compared with neat PET, while combustion rate is decreased both in the bulk material and in textiles made of fibers spun from the compound. Copyright © 2010 John Wiley & Sons, Ltd.     

Optimization of the procedure to burn textile fabrics by cone calorimeter: Part I. Combustion behavior of polyester

The aim of this study was the optimization of cone calorimeter to determine the burning behavior of textile fabrics. In particular, the combustion behavior of commercial polyester textile fabrics with varying densities was studied in terms of time to ignition (TTI), heat release rate (HRR), and relative peak (pkHRR) were monitored. Reproducibility and repeatability of the data have been verified by the influence of instrument variable including incident heat flux, the temperature of ceramic backing pads and retaining grid used during sample mounting as well as sample weight (as the number of fabric layers), the density of textiles, and the relative humidity. A low reproducibility has been obtained when a wire grid was not used to stabilize samples during the tests. The effects of these variables on TTI and pkHRR were observed. Copyright © 2010 John Wiley & Sons, Ltd.     

液硫脱气与克劳斯尾气处理

采用三氧化二铝或二氧化硅固体催化剂进行的最新实验室研究表明,H2Sx先在催化剂表面的碱性位分解为H2S,然后被吹扫气从液硫中驱除出去.由于H2S从气相返回液相的传质是一个有限的过程,从理论上讲,这预示着可利用克劳斯尾气作为吹扫气.试验还揭示,在涂有三氧化二铝的堇青石上,脱气期间尾气中约60％的H2S和SO2转化为元素硫.这预示着(例如)可在硫冷凝器管内衬入涂有三氧化二铝的堇青石管,以在脱气的同时提高总转化率.     

Validation of a Method for Quantitation of Soybean Lectin in Commercial Varieties

Soybean agglutinin (SBA) protein, also known as soybean lectin, is regarded as an anti‐nutrient due to its negative effect on the ability of monogastric animals to gain weight following consumption of raw soybean seed. Historically, SBA has been measured using a time‐consuming and cumbersome hemagglutination procedure. The objective of our research was to obtain a validated methodology that is precise and accurate in the measurement of SBA while allowing minimally equipped laboratories to effectively conduct the analysis, thus our focus was on evaluating an existing commercially available ELISA, an enzyme‐linked‐lectin‐assay (ELLA), and a hybrid ELISA/ELLA. A new ELLA technique that can detect and quantify lectins was chosen and modified specifically for the quantitation of SBA in soybean seed. The proposed ELLA methodology is similar to a standard sandwich ELISA, and uses polyacrylamide‐linked N‐acetylgalactosamine (Gal–NAc–PAA) for a capture phase and the biotinylated version (Gal–NAc–PAA–Biotin) for detection. Based upon the validation data, the ELLA method can precisely and accurately determine soybean lectin levels in soybean seed. The validated ELLA method was used to quantify SBA in nine commercial soybean varieties introduced between 1972 and 2008 and demonstrated that the natural variability of SBA is subject to the effects of genotype and environment.     

Structure and analgesic properties of layered double hydroxides intercalated with low amounts of ibuprofen

Ibuprofen‐intercalated layered double hydroxides (LDH‐IBU) have been successfully synthesized via a coprecipitation method with a nominal [Al³⁺]/[Mg²⁺] ratio of 0.5 and a variable molar IBU/([Al³⁺]+[Mg²⁺]) ratio of 0, 0.15, 0.18, 0.24, 0.36, and 0.72. After an accurate determination of the composition, the nature of the intercalated species and the effective intercalation yield from to IBU, it is shown that the synthesis route used allows a good control of the quantity of intercalated IBU within the LDH framework. This results in different samples with full or partial IBU intercalation in the interlayer space in exchange of nitrate anions. The analysis of the X‐ray diffraction basal reflections reveals that the intercalation of IBU in the framework only increases the basal distances with no alteration of the brucite‐type layers. Also, a computational study used to model the positions and shapes of the basal reflections showed that the structure of the nonfully intercalated compounds follows a random interstratification scheme. Finally, three samples ranging from slightly to fully IBU‐intercalated galleries were selected for preliminary in vivo assays. These tests showed a strong tendency that after 24 hours the low yield of IBU‐intercalated compounds are almost as efficient as the fully intercalated sample.     

Solvent and Extraction Conditions Control the Assayable Phenolic Content and Antioxidant Activities of Seeds of Black Beans,Canola and Millet

The effects of extraction solvent and conditions on the total phenolic content (TPC) and antioxidant activity of black beans, canola and foxtail millet were investigated. The antioxidant activity was assayed using 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity (DRSA) and oxygen radical absorbance capacity (ORAC). Four solvent systems, namely 70 % acetone, 80 % ethanol, 80 % methanol and a mixture of acetone/methanol/water (7:7:6, v/v/v) were used. The extraction methods adopted in this study included refluxing, homogenization, cold extraction and sonication. The TPC as measured using the Folin Ciocalteu's method were 12.35–28.39, 2.43–16.73, and 1.78–5.06 µmol catechin equivalents/g dry matter (dm) for canola, black beans and foxtail millet, respectively. Aqueous acetone afforded the highest TPC for black beans and canola. Within the same solvent system used, the TPC, DRSA and ORAC obtained from different extraction techniques differed for black beans, canola and foxtail millet. The results demonstrated that the solvent system as well as method influenced the extraction of phenolic compounds and their antioxidant activities, depending on the type of matrix in which phenolics were embedded.     

Characterization of particle emissions from consumer fused deposition modeling 3D printers

Particle emissions from multiple fused deposition modeling consumer 3D printers were systematically quantified utilizing an established emission testing protocol (Blue Angel) to allow quantitative exposure assessments for printers operating in different environments. The data are consistent with particle generation from volatilization of the polymer filament as it is heated by the extruder. Typically, as printing begins, a burst of new particle formation leads to the smallest sizes and maximum number concentrations produced throughout the print job. For acrylonitrile butadiene styrene (ABS) filaments, instantaneous concentrations were up to 10⁶ #/cm³ with mean particle sizes of 20 to 40 nm when measured in a well mixed 1 m³ chamber with 1 air change per hour. Particles are continuously formed during printing and the size distribution evolves consistent with vapor condensation and particle coagulation. Particles emitted per mass of filament consumed (particle yield) varied widely due to factors including printer brand, and type and brand of filament. Higher extruder temperatures result in larger emissions. For filament materials tested, average particle number yields ranged from 7.3 × 10⁸ to 5.2 × 10¹⁰ g^?1 (approximately 0.65 to 24 ppm), with trace additives apparently driving the large variations. Nanoparticles (diameters less than 100 nm) dominate number distributions, whereas diameters in the range of 200 to 500 nm contribute most to estimated mass. Because 3D printers are often used in public spaces and personal residences, the general public and particularly susceptible populations, such as children, can be exposed to high concentrations of non-engineered nanoparticles of potential toxicity.

Copyright © 2017 American Association for Aerosol Research     

Miniemulsion polymerization for synthesis of structured clay/polymer nanocomposites: Short review and recent advances

This review intends to present different aspects concerning clay/polymer nanocomposites produced by heterophase polymerization in aqueous media. This paper highlights the ability of miniemulsion polymerization to produce clay/polymer nanoparticles with tailored nanostructures. Indeed, this polymerization route enables the synthesis of composite nanoparticles with the clay platelets located either on the surface of the polymer particle or embedded inside the polymer particle. A focus is given on the influence of these nanostructures on the properties of the final material through a direct comparison of the composites obtained after water evaporation from these structured nanoparticles. Indeed, the film obtained from the film forming process of these nanoparticles present significantly different nanostructures and exhibit totally different mechanical behaviours and water uptakes. By comparing experimental results and modeling approaches, it is demonstrated that their properties are clearly related to the clay dispersion and contacts. It is also evidenced that the main drawback of miniemulsion from the coating application point of view, is the large water uptake promoted by the surfactant presence whose localization is strongly influenced by nanostructuration. This stresses the need for the further development of surfactant free miniemulsion polymerization using advantageously the clay presence to stabilize the emulsion.