IFU observations of luminous type II AGN - I. Evidence for ubiquitous winds

We present observations of 17 luminous (log(L[O III]/L_Sun) > 8.7) local (z < 0.11) type II AGN. Our aim is to investigate the prevalence and nature of AGN driven outflows in these galaxies by combining kinematic and ionization diagnostic information. We use non-parametric methods (e.g. W80, the width containing 80% of the line flux) to assess the line widths in the central regions of our targets. The maximum values of W80 in each galaxy are in the range 400 - 1600 km/s, with a mean of 790 +- 90 km/s. Such high velocities are strongly suggestive that these AGN are driving ionized outflows. Multi-Gaussian fitting is used to decompose the velocity structure in our galaxies. 14/17 of our targets require 3 separate kinematic components in the ionized gas in their central regions. The broadest components of these fits have FWHM = 530 - 2520 km/s, with a mean value of 920 +- 50 km/s. By simultaneously fitting both the H{\beta}/[O III] and H{\alpha}/[N II] complexes we construct ionization diagnostic diagrams for each component. 13/17 of our galaxies show a significant (> 95 %) correlation between the [N II]/H{\alpha} ratio and the velocity dispersion of the gas. Such a correlation is the natural consequence of a contribution to the ionization from shock excitation and we argue that this demonstrates that the outflows from these AGN are directly impacting the surrounding ISM within the galaxies.Comment: 37 pages, 30 figures. Accepted for publication in MNRA

Benign solvents for recycling and re-use of a multi-layer battery pouch.

This article describes a process for the repair and re-use of an aluminium-containing pouch used as an outer casing for a Lithium-ion battery cell. As Lithium-ion batteries become more widespread, particularly with their increasing use in the automotive industry and in consumer electronics, recycling them is becoming an important challenge. Current recycling approaches for Li-ion batteries focus on reclamation of the high-value metals found in the electrodes. However, in order to minimise the environmental impact of the battery it would be optimal to be able to reclaim and re-use other components. Since many battery cells consist of an electrode stack held inside an outer pouch, we herein describe the structure of such a pouch and suggest methods for selectively stripping and repairing the inner layer, allowing the material to be re-used. We investigated the use of three different solvents (xylene, limonene, and 2,2,5,5-tetramethyloxolane) for the selective stripping of the polypropylene (PP) layer on the inner side of a pouch material. Each solvent was tested on both ‘pristine’ pouch material (as obtained from the manufacturer) and pouch material that had previously been part of a battery. For ‘used’ pouch material, the overall thickness of the film decreased from 150-160μm to 70-80 μm in under 1hr for all three solvents (corresponding to the removal of the PP layer), whereas for the ‘pristine’ pouch higher temperatures and longer times were required; this result is suggestive of some polymer degradation during the life of the pouch. Following the removal of the PP layer, virgin PP was subsequently added to renew the multi-layer structure

Assessing Air Quality Impacts of Greener Chemicals:Beyond Traditional Metrics

The atmospheric fate and air quality impacts of “greener” substitute chemicals are generally neglected. Air quality metrics can be straightforwardly estimated from molecular structures to screen new compounds for negative impacts

Biologically bound nickel accelerated de-polymerization of polyethylene to high value hydrocarbons and hydrogen

The goal of a carbon-neutral society can be realized by utilizing a circular carbon pathway, which combines recycling, biomass utilization, carbon capture and utilization. Inspired by the potential of metal-contaminated biomass and plastic waste as valuable feed-stocks, we have developed a biologically-bound nickel catalyst (Ni-phytocat) to accelerate de-polymerization of polyethylene into high value chemicals. The synergistic effect of microwaves, together with Ni-phytocat as microwave absorbers, accelerate the catalytic de-polymerization process at low temperature (250 °C). The single step process typically takes up to 70 s to transform a sample of low-density polyethylene into liquid hydrocarbons (40–60% oil yield), hydrogen (11–30% gas yield) and filamentous carbon (25–37% solid yield), depending on varying catalyst to polymer weight ratios. The Ni-phytocat enhanced the production of C6–C12 aliphatics (up to 56% selectivity) and favored the aromatization of linear alkanes to form monocyclic aromatics (up to 33% selectivity), thereby releasing more H2 (up to 74% selectivity) as gaseous fractions. The enhancement of (de)hydrogenation, de-carboxylation and cyclization, utilizing Ni-phytocat can be established as a proof of concept to advance and enable selective transformation of polymeric consumer products, paving the way to harness complete circular chemical potential of these future feed-stocks

Cyrene™, a Sustainable Solution for Graffiti Paint Removal

Graffiti can create detrimental aesthetic and environmental damage to city infrastructure and cultural heritage and requires improved removal methods. Incumbent laser, mechanical and chemical removal techniques are often not effective, are expensive or damage the substrate. Solvents are generally hazardous and not always effective because of the insolubility of the graffiti paint. This study proposes a simple strategy for safe and effective graffiti removal, using the bio-based, non-toxic and biodegradable solvent dihydrolevoglucosenone (Cyrene™). The results showed that the type of substrate influenced the cleaning performance; in benchmark studies a non-porous substrate was easy to clean, while porous ceramic showed the presence of residual paint and yellowing when the conventional polar aprotic solvents were used. Cyrene, however, showed good removability of graffiti paint from both glazed and porous substrates, with little paint remaining in the pores of ceramic tiles. The paint suffered a reversible change in colour and a selective solubility of its components when using N-methyl-2-pyrrolidone; no changes occurred when Cyrene was used. While N-methyl-2-pyrrolidone and N,N′-dimethylformamide were only effective when neat, a Cyrene–water mixture showed some cleaning results. The performance of Cyrene was validated with Hansen solubility parameters and represents a greener and more sustainable solvent for paint removal

A class of surfactants via PEG modification of the oleate moiety of lactonic sophorolipids : synthesis, characterisation and application

There is ever increasing demand to develop surfactants based on sophorolipids because they are produced by non-pathogenic organisms, biodegradable and less toxic to humans and the environment. Herein, commercially available lactonic sophorolipid was modified via epoxidation of the fatty acid units C[double bond, length as m-dash]C and subsequent ring-opening of the oxirane with poly(ethylene glycol) of vary chain lengths to deliver a novel range of non-ionic sophorolipid-based surfactants. The methods employed for ring-opening reaction lead to a final surfactant synthesis involving heterogeneous catalysis (metal-exchanged montmorillonite), use of a benign solvent (ethyl acetate) and short reaction time (60 minutes). The resulting surfactants were structurally characterised and a prediction of their potential applications achieved using the hydrophilic-lipophilic balance (HLB) concept, foam capacity and stability of the surfactants at 0.25% surfactant solution. This new family of bio-derivable non-ionic surfactants will be useful as wetting and solubilising agents, oil-in-water emulsifiers and detergents

Biomass Derived, Hierarchically Porous, Activated Starbons® as Adsorbents for Volatile Organic Compounds

The use of potassium hydroxide activated Starbons® derived from starch and alginic acid as adsorbents for 29 volatile organic compounds (VOCs) was investigated. In every case, the alginic acid derived Starbon (A800K2) was found to be the optimal adsorbent, significantly outperforming both commercial activated carbon and starch derived, activated Starbon (S800K2). The saturated adsorption capacity of A800K2 depends on both the size of the VOC and the functional groups it contains. The highest saturated adsorption capacities were obtained with small VOCs. For VOC's of similar size, the presence of polarizable electrons in lone pairs or π-bonds within non-polar VOCs was beneficial. Analysis of porosimetry data suggests that the VOC's are being adsorbed within the pore structure of A800K2 rather than just on its surface. The adsorption was completely reversible by thermal treatment of the saturated Starbon under vacuum

Spray coating polymer substrates from a green solvent to enhance desalination performances of thin film composites

Toxic solvents like n,n-dimethylformamide (DMF), n,n-dimethylethanamide (DMAc), and 1-methyl-2-pyrrolidone (NMP) are commonly used to fabricate polymer support membranes. Replacing these toxic solvents with green solvents such as Cyrene™ can imbue sustainability into membrane fabrication, but at the expense of poor membrane separation performances. Here we overcome this limitation by spray coating Cyrene™-based polymer dope solutions to form highly porous asymmetric membranes. The pure water flux of spray coated polyethersulfone (PES) membranes reached 206.6 L m-1 h-1, 7-folds higher than knife cast membranes. This significant increase in flux was ascribed to a porous, thin skin layer and macrovoids interconnected with finger-like pores in spray coated PES films. However, this did not impact on the ability to yield thin film composites (TFCs) with high separation performances. Through interfacial polymerisation, we deposited a polyamide selective layer on to the surface of spray coated PES films to yield TFCs for desalination of a 2000 ppm NaCl solution. The salt rejection rate and flux of such TFCs reached 93 % and 5.3 L m-1 h-1, respectively. This desalination performance was similar to knife cast membranes produced from DMF-, NMP- and DMAc-based polymer dope solutions, but fabricated here in a more sustainable manner. This indicated that spray coating could overcome the trade-off between poor membrane separation performance and sustainability

3-Methoxybutan-2-one as a sustainable bio-based alternative to chlorinated solvents

Methylation of acetoin with dimethyl carbonate was performed in a sustainable one-step process, with improved process mass intensity (PMI) and atom economy compared to previously published methods. The resulting product, 3-methoxybutan-2-one (MO) was successfully evaluated as a bio-based solvent, while both Kamlet–Taft solvatochromic parameters and Hansen solubility parameters demonstrate its potential viability in the substitution of chlorinated solvents. MO exhibited a low peroxide forming potential and a negative Ames mutagenicity test and was successfully used as a solvent in a Friedel–Crafts acylation (79% yield compared to 77% in dichloromethane) and for N-alkylations. MO is a renewable oxygenated solvent, with the potential ability to substitute carcinogenic halogenated solvents in some applications