Polymeric colorants: Statistical copolymers of indigo building blocks with defined structures

Statistical copolymers of indigo (1a) and N-acetylindigo (1b) building blocks with defined structures were studied. They belong to the class of polymeric colorants. The polymers consist of 5,5′-connected indigo units with keto structure and N-acetylindigo units with uncommon tautomeric indoxyl/indolone (=1H-indol-3-ol/3H-indol-3-one) structure (see 2a and 2b in Fig. 1). They formed amorphous salts of elongated monomer lengths as compared to monomeric indigo. The polymers were studied by various spectroscopic and physico-chemical methods in solid state and in solution. As shown by small-angle-neutron scattering (SANS) and transmission-electron microscopy (TEM), disk-like polymeric aggregates were present in concentrated solutions (DMSO and aq. NaOH soln.). Their thickness and radii were determined to be ca. 0.4 and ca. 80 nm, respectively. From the disk volumes and by a Guinier analysis, the molecular masses of the aggregates were calculated, which were in good agreement with each other. Defined structural changes of the polymer chains were observed during several-weeks storage in concentrated DMSO solutions. The original keto structure of the unsubstituted indigo building blocks reverted to the more flexible indoxyl/indolone structure. The new polymers were simultaneously stabilized by intermolecular H-bonds to give aggregates, preferentially dimers. Both aggregation and tautomerization were reversible upon dissolution. The polymers were synthesized by repeated oxidative coupling of 1,1′-diacetyl-3,3′-dihydroxybis-indoles 5 (from 1,1′-diacetyl-3,3′-bis(acetyloxy)bis-indoles 6) followed by gradual hydrolysis of the primarily formed poly(N,N′-diacetylindigos) 7 (Scheme). N,N′-Diacetylbis-anthranilic acids 9 were isolated as by-products.

Removal of natural organic matter though membrane filtration and subsequent effect on disinfectant decay

This study aims to evaluate the effectiveness of membrane filtration in removing natural organic matters (NOMs) from four different source waters and the subsequent effect that it has on total chlorine (TC) demand of these waters. Source water samples were filtered sequentially through membranes with molecular weight cut-off of 3,500, 1,000 and 200 Da as well as RO membrane. The source waters and sequentially filtered samples were dosed with chlorine and the residual chlorine data were used to estimate the TC demand of these waters. A robust chlorine decay model constructed in AQUASIM software was used to do so. More than 80% of the chlorine demand in untreated surface water sources was found to be contributed mainly by NOMs that were larger than 3,500 Da. However, for water treated by granular filtration, the chlorine demand was found to be contributed by NOMs which were down to 200 Da. Sequential filtration through all four membranes reduced chlorine demand by more than 94% in surface waters and 84% in waters treated by granular filtration. Significant reduction in the formation of trihalomethane can be achieved if water is treated by appropriate membranes after granular media filtration. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

The properties of fly ash based geopolymer mortars made with dune sand

Geopolymer cement utilises industrial by-products and is associated with low CO2 emissions. The use of dune sand as fine aggregate could reduce the environmental impact of mining activities. The present study is to examine the feasibility of using dune sand in geopolymer-based construction materials. The geopolymer mortars made with dune sand (DSM) were prepared by using alkali activators of different cations(Na, K and Na/K). In order to compare, the corresponding geopolymer mortars made with normal sand (NSM) were also prepared. It was found that dune sand has little influence on the strength of geopolymer mortars, especially for K based mortars. However, the alkali cation has significant influence on the compressive strength of geopolymer mortars. This influence was found to be correlated to porosity. Low compressive strength is associated with high porosity. For all investigated alkali cations, the tensile strengths of DSM compare favourably to those predicted by the relevant Standards for construction materials. Based on the experimental results, Australian dune sand can be used as fine aggregate for the production of geopolymer based construction materials.

Heritagescaping and the aesthetics of refuge: challenges to urban sustainability

The year 2012 marked the fortieth anniversary of UNESCO’s Convention Concerning the Protection of the World Cultural and Natural Heritage, or World Heritage
Convention. Regarded by many as a hugely successful project, World Heritage has
provided a framework for safeguarding a wide array of historic built environments.
The choice of “sustainable development and the role of communities” as the theme of
the fortieth anniversary was, however, recognition of the significant problems and
challenges this arena of cultural and spatial governance has created for those living in
and around listed sites. Cities have proved particularly challenging, and resistant to
prescriptive modeling at the level of international policy. Evictions, punitive
legislation, rising living costs, and loss of community are the now familiar by‐products of worldheritage that continue to go undocumented and ignored.
Against this backdrop, this chapter traces recent developments and trends surrounding urban heritage conservation, highlighting recent turns towards community‐driven approaches and discourses of sustainability. It then raises the issue of gentrification, with a particular focus on where such problems take on critical importance: small‐scale urban environments. Focusing on Galle in Sri Lanka, the final part of the chapter explores the emergence of a form of “heritagescaping” oriented by an aesthetics of solitude, tran-quility, and quiet comfort. In offering a contribution towards debates around urban sustainability and the role of heritage therein, it is argued that such processes present significant obstacles to the development of more community‐based, culturally sustainable forms of heritage conservation.

'Iconic development' : is there such a thing?

By way of definition, dictionaries such as the Oxford Dictionary note that the word ‘icon’ is a noun meaning ‘a person or thing regarded as a representative symbol or as worthy of veneration’ (p. 654). More recently, the phrase ‘iconic development’ has crept into the town planning vernacular making reference to built or planned works that are intended to be an urban ‘benchmark’. However, in terms of planning practice in the State of Victoria, Australia, the meaning of ‘iconic development’ is unclear amongst property development professionals – one only needs to peruse the local newspaper, The Age on any given week and publications by key bodies such as the Planning Institute of Australia, the Victorian Planning and Environment Law Association, the Urban Development Institute of Australia and the Property Council of Australia on their websites and in professional newsletters, to appreciate the different ways the phrase is used in the property development context. This paper reports on key themes arising from interviews with 52 Victorian property development professionals, who were interviewed to determine their perceptions about what constitutes ‘iconic development’ in Victoria. Arising from the interviews, the study confirms that ‘iconic development’ is the new buzz phrase in property development circles, it is no longer just being used as a sales and marketing tool, but has been appropriated by technical professionals and introduced into different planning documents including certain local clauses in the Victorian Planning Provisions. Different professionals in the development industry, such as architects, planners and lawyers ascribe different meanings to this phrase, thereby presenting confusion in the property development industry. By understanding what these different professionals mean by the phrase ‘iconic development’ a more collaborative understanding of the phrase is arrived at to provide the practitioner and public with a more informed understanding to review realised and/or planned 'iconic development’.

A review on the assessment of stress conditions for simultaneous production of microalgal lipids and carotenoids

Microalgal species are potential resource of both biofuels and high-value metabolites, and their production is growth dependent. Growth parameters can be screened for the selection of novel microalgal species that produce molecules of interest. In this context our review confirms that, autotrophic and heterotrophic organisms have demonstrated a dual potential, namely the ability to produce lipids as well as value-added products (particularly carotenoids) under influence of various physico-chemical stresses on microalgae. Some species of microalgae can synthesize, besides some pigments, very-long-chain polyunsaturated fatty acids (VL-PUFA,>20C) such as docosahexaenoic acid and eicosapentaenoic acid, those have significant applications in food and health. Producing value-added by-products in addition to biofuels, fatty acid methyl esters (FAME), and lipids has the potential to improve microalgae-based biorefineries by employing either the autotrophic or the heterotrophic mode, which could be an offshoot of biotechnology. The review considers the potential of microalgae to produce a range of products and indicates future directions for developing suitable criteria for choosing novel isolates through bioprospecting large gene pool of microalga obtained from various habitats and climatic conditions.

Playing with other(ed) species: games, representation, and nonhuman animals

During the writing of this essay, the controversial nonhuman animal rights organisation PETA (People for the Ethical Treatment of Animals) sent out a tweet linking to an online article about the recent PC and Playstation 4 console game No Man’s Sky, in which players are positioned as explorers of countless virtual planets. Encountering the wide array of creatures indigenous to these worlds, players of this game are offered the choice of whether ‘to document them and name them or slaughter them en masse’ (Francisco, ‘PETA’). While an environmental agenda appears to be far from the game designers’ minds, PETA’s Marketing Vice President Joel Bartlett interprets No Man’s Sky as ‘counting on our natural empathy … we have a natural sense of exploration that has been important to human history’ (Francisco, ‘PETA’). Indeed, PETA has immersed itself in the gaming industry by creating its own simple online games in-house, such as the provocative Mario Kills Tanooki, which opposes what it sees as the unethical messages conveyed by Nintendo’s popular Super Mario Bros. franchise. These instances of the intersection of exploration, ethics, empathy, and play raise important questions regarding the potential role(s) of gaming in furthering (or hindering) the welfare of nonhuman animals. This issue becomes more and more urgent not only in a time of ongoing climate change, environmental degradation, and the continued endangerment of countless species around the planet, but also in a time when the gaming industry and the adoption of game design principles in many others grows apace.