Strength improvement in silty clay by microbial-induced calcite precipitation

Bulletin of Engineering Geology and the Environment - The application of MICP (microbial-induced calcite precipitation) to clays has been restricted due to their low permeability and small pore...     

Chromatographic characterisation of aptamer-modified poly(EDMA-co-GMA) monolithic disk format for protein binding and separation

The introduction of aptameric ligands onto disk-monolithic adsorbent, representing a unique strategy for convective isolation of target molecules with high specificity and selectivity, is investigated for the first time. Experimental results showed that the disk monolith possessed a good permeability of 1.67 ± 0.05 × 10^–14 m² (RSD = 3.2%). The aptameric ligand density for the aptamer-modified disk monolith was 480 pmol/uL. Chromatographic analysis of the aptamer disk-monolith efficiency showed an optimum linear velocity of 126 cm/min (≈0.25 mL/min) at room temperatures 25 ± 2°C. The theoretical number of plates corresponding to the optimum linear velocity was 128.2 with an height equivalent to the theoretical plate of 0.022 mm. The disk aptamer-immobilised monolithic system demonstrated good selectivity and isolation of thrombin from non-targets.     

Synthesis of Novel Phosphonic‐Type Activity‐Based Probes for Neutrophil Serine Proteases and Their Application in Spleen Lysates of Different Organisms

Neutrophils are a type of granulocyte important in the “first line of defense” of the innate immune system. Upon activation, they facilitate the destruction of invading microorganisms by the production of superoxide radicals, as well as the release of the enzymatic contents of their lysozymes. These enzymes include specific serine proteases: cathepsin G, neutrophil elastase, proteinase 3, as well as the recently discovered neutrophil serine protease 4 (NSP4). Under normal conditions, the proteolytic activity of neutrophil proteases is tightly regulated by endogenous serpins; however, this mechanism can be subverted during tissue stress, thereby resulting in the uncontrolled activity of serine proteases, which induce chronic inflammation and subsequent pathology. Herein, we describe the development of low‐molecular‐weight activity‐based probes that specifically target the active sites of neutrophil proteases.     

Microstructural hot corrosion behaviour of austenitic Fe-29.7Mn-8.7Al-1.04C alloy in fused Na2SO4 and Na2SO4-NaCl mixture

A short-time hot corrosion test was performed on the austenitic Fe-29.7Mn-8.7Al-1.04C alloy in sodium sulphate at 900°C. The corrosion scales formed on the alloy investigated were studied by scanning electron microscopy and X-ray mapping techniques. The hot-corrosion scales morphology of the austenitic Fe-29.7Mn-8.7Al-1.04C alloy were characterized by the formation of Al₂S₃ and α-MnS sulphides at and beneath the internal alumina scale. No fluxing of the scales was observed. The effect of the addition of sodium chloride to the fused sodium sulphate on the hot corrosion scales morphology was also investigated.     

Spark Plasma Sintered Hydroxyapatite/Multiwalled Carbon Nanotube Composites With Preferred Crystal Orientation

Hydroxyapatite (HA) and its nanocomposites reinforced with low loading levels of multiwalled carbon nanotubes (MWNTs) are prepared by spark plasma sintering process. The structure, morphology, and hardness of sintered HA and MWNT/HA nanocomposites are characterized by means of X‐ray diffraction (XRD), scanning electron microscopy and nanoindentation techniques. XRD results show that the orientation of crystallographic planes of sintered HA are highly related to the applied pressure direction. The perpendicular section of sintered MWNT/HA nanocomposites shows predominantly oriented HA a‐and b‐planes while the parallel section displays a dominant c‐plane orientation. The hardness of MWNT/HA nanocomposites improves considerably with increasing MWNT content.     

DOPO‐VTS‐based coatings in the realm of fire retardants for cotton textile

The work elucidates the feasibility of incorporation of phosphorus‐silicon containing fire retardant (10‐(2‐trimethoxysilyl‐ethyl)‐9‐hydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide [DOPO‐VTS]) into nanosol coating solutions by cohydrolysis cocondensation reaction of DOPO‐VTS with tetraethoxysilane precursor (TEOS). Impregnation of cotton with the organophosphorus silane in a form of nanosol dispersion afforded better fire retardancy of such samples compared to pure DOPO or TEOS‐treated cotton indicating synergism between phosphorus and silicon containing species in a condensed phase. The detailed analysis by TGA‐MS and SEM pointed to the fact that DOPO‐VTS acts as a promoter of cotton degradation which, in turn, results in acceleration of the charring process and formation of compact char in contrast to TEOS‐treated samples. Further analysis of the char by XPS confirmed high content of carbonaceous residue in the case of DOPO‐VTS‐treated samples while mainly siliceous component was left in the char in case of cotton treated with TEOS. Standard flammability test (EN ISO 15025:2008) additionally confirmed the absence of smoldering and better overall fire performance of the DOPO‐VTS samples in contrast to TEOS‐treated samples. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41955.     

The Effect of Compatibilization of Maleated Polypropylene on a Blend of Polyamide-6 and Liquid Crystalline Copolyester

Blends of polyamide-6 (PA6) and thermotropic liquid crystalline polymer (LCP) compatibilized with various maleic-anhydride-grafted polypropylene (MAP) contents were injection-moulded. The effect of compatibilization on the mechanical properties of the blends was investigated by means of tensile testing, drop weight Charpy impact measurement and dynamic mechanical analysis. The static tensile measurement showed that the strain-at-break depends strongly on the MAP content. The impact test also indicated that the critical strain energy release rate (G_IC) is dependent on the MAP concentration. These results revealed that the 80%PA6/MAP(86/14)–20%LCP blend exhibits the highest strain-at-break and G_IC values. Moreover, the tensile ductility and impact toughness tended to decrease dramatically with increasing MAP content. This was attributed to the chemical and thermal decomposition of PA6 during blending for the LCP/PA6 blends containing higher MAP concentration. © of SCI.