1,959 research outputs found

    Phycoremediation of municipal wastewater by microalgae to produce biofuel

    Get PDF
    Municipal wastewater (WW), if not properly remediated, poses a threat to the environment and human health by carrying significant loads of nutrients and pathogens. These contaminants pollute rivers, lakes and natural reservoirs where they cause eutrophication and pathogen-mediated diseases. However, the high nutrient content of WW makes it an ideal environment for remediation with microalgae that require high nutrient concentrations for growth and are not susceptible to toxins and pathogens. Given that an appropriate algal strain is used for remediation, the incurred biomass can be refined for the production of biofuel. Four microalgal species (Chlamydomonas reinhardtii, Chlorella sp., Parachlorella kessleri-I and Nannochloropsis gaditana) were screened for efficient phycoremediation of municipal WW and potential use for biodiesel production. Among the four strains tested, P. kessleri-I showed the highest growth rate and biomass production in 100% WW. It efficiently removed all major nutrients with a removal rate of up to 98% for phosphate after ten days of growth in 100% municipal WW collected from Delhi. The growth of P. kessleri-I in WW resulted in a 50% increase of biomass and a 115% increase of lipid content in comparison to growth in control media. The FAME and fuel properties of lipids isolated from cells grown in WW complied with international standards. The present study provides evidence that the green alga P. kessleri-I effectively remediates municipal WW and can be used to produce biodiesel

    The competitiveness of nations and implications for human development

    Get PDF
    This is the post-print version of the final paper published in Socio-Economic Planning Sciences. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.Human development should be the ultimate objective of human activity, its aim being healthier, longer, and fuller lives. Thus, if the competitiveness of a nation is properly managed, enhanced human welfare should be the key expected consequence. The research described here explores the relationship between the competitiveness of a nation and its implications for human development. For this purpose, 45 countries were evaluated initially using data envelopment analysis. In this stage, global competitiveness indicators were taken as input variables with human development index indicators as output variables. Subsequently, an artificial neural network analysis was conducted to identify those factors having the greatest impact on efficiency scores

    Differential maturation and subcellular localization of severe acute respiratory syndrome coronavirus surface proteins S, M and E

    Get PDF
    Post-translational modifications and correct subcellular localization of viral structural proteins are prerequisites for assembly and budding of enveloped viruses. Coronaviruses, like the severe acute respiratory syndrome-associated virus (SARS-CoV), bud from the endoplasmic reticulum-Golgi intermediate compartment. In this study, the subcellular distribution and maturation of SARS-CoV surface proteins S, M and E were analysed by using C-terminally tagged proteins. As early as 30 min post-entry into the endoplasmic reticulum, high-mannosylated S assembles into trimers prior to acquisition of complex N-glycans in the Golgi. Like S, M acquires high-mannose N-glycans that are subsequently modified into complex N-glycans in the Golgi. The N-glycosylation profile and the absence of O-glycosylation on M protein relate SARS-CoV to the previously described group 1 and 3 coronaviruses. Immunofluorescence analysis shows that S is detected in several compartments along the secretory pathway from the endoplasmic reticulum to the plasma membrane while M predominantly localizes in the Golgi, where it accumulates, and in trafficking vesicles. The E protein is not glycosylated. Pulse-chase labelling and confocal microscopy in the presence of protein translation inhibitor cycloheximide revealed that the E protein has a short half-life of 30 min. E protein is found in bright perinuclear patches colocalizing with endoplasmic reticulum markers. In conclusion, SARS-CoV surface proteins S, M and E show differential subcellular localizations when expressed alone suggesting that additional cellular or viral factors might be required for coordinated trafficking to the virus assembly site in the endoplasmic reticulum-Golgi intermediate compartment. © 2005 SGM.postprin

    The role of national intellectual capital in the digital transformation of EU countries. Another digital divide?

    Get PDF
    Purpose: This study, an exploratory one, aims to empirically investigate the association of national intellectual capital (NIC) with the national digital transformation readiness of the European Union's (EU’s) member states. Apart from building the conceptual model of NIC, this study explores the role of NIC dimensions in the digital divide between European countries. Design/methodology/approach: Based on the literature review and the available EU statistical data and indexes, the theoretical framework and conceptual model for NIC were developed. The model explores the relation of NIC and its dimensions (human, social, structural, relational and renewable/development capital) on the readiness of European countries for digital transformation and the digital divide. Significant differences between EU countries in NIC and digital readiness were tested. Multiple linear regression was used to explore the association of each NIC dimension with digital transformation and digital divide within the EU. Findings: Despite a positive association between all dimensions of NIC and digital transformation readiness, the proposed model of NIC was not confirmed in full. Regression analysis proved social capital and working skills, a dimension of human capital, to be the predictors of digital transformation at a national level, able to detect certain elements of digital divide between EU member states. Structural capital, knowledge and education, as dimensions of human capital, were predictors of the digital divide in terms of the integration of digital media in companies. Research limitations/implications: This research has a limited propensity for generalisation due to the lack of common measurement models in the field of NIC exploration. Practical implications: This research offers policy makers an indication of the relationships between NIC and digital transformation, pointing out which dimensions of NIC should be strengthened to allow the EU to meet the challenges of digital economy and to overcome the digital divide between EU member states. Social implications: The use of digital technologies is key in creating active and informed citizens in the public sphere and productive companies and economic growth in the business sphere. Originality/value: This study provides an original theoretical framework and conceptual model through which to analyse the relationship between NIC and digital transformation, which has thus far not been explored at the level of the EU. This research makes an original contribution to the empirical exploration of NIC and produces new insights in the fields of digital transformation and intellectual capital

    Progress in the synthesis of sustainable polymers from terpenes and terpenoids

    Get PDF
    The imminent depletion of resources derived from fossil fuels is a major concern for today’s society. 300 Mt of polymers are used every year in the form of plastics, most commonly derived from fossil fuels, hence the necessity to find new materials based on renewable resources. This review explores the utilisation of monoterpenes and terpenoids – a family of abundant and inexpensive natural products – as promising renewable monomers. Terpenes can be directly used in polymerisations or converted into bespoke monomers through organic transformations. The use of terpenes for the production of renewable plastics has been a prevalent topic of research for the past few decades. Early research focused on cationic polymerisation of terpenes by way of their alkene moieties; however, more recently terpenes are being functionalised to incorporate handles for a larger range of polymerisation techniques. Herein an assessment of the future prospects for the use of these small functional molecules to synthesise novel and valuable renewable materials is presented

    Effect of filter media thickness on the performance of sand drying beds used for faecal sludge management

    Get PDF
    The effect of sand filter media thickness on the performance of faecal sludge (FS) drying beds was determined in terms of: dewatering time, contaminant load removal efficiency, solids generation rate, nutrient content and helminth eggs viability in the dried sludge. A mixture of VIP-latrine sludge and septage in the ratio 1:2 was dewatered using three pilot-scale sludge drying beds with sand media thicknesses of 150 mm, 250 mm and 350 mm. Five dewatering cycles were conducted and monitored for each drying bed. Although 150 mm filter had the shortest average dewatering time of 3.65 days followed by 250 mm and 350 mm filters with 3.83 and 4.02 days, respectively, there was no significant difference ( p > 0.05) attributable to filter media thickness configurations. However, there was a significant difference for the percolate contaminant loads in the removal and recovery efficiency of suspended solids, total solids, total volatile solids, nitrogen species, total phosphorus, COD, DCOD and BOD, with the highest removal efficiency for each parameter achieved by 350 mm filter. There were also significant differences in the nutrient content (NPK) and helminth eggs viability of the solids generated by the tested filters. Filtering media configurations similar to 350 mm have the greatest potential for optimising nutrient recovery from FS

    Study of 16 Portuguese activated sludge systems based on filamentous bacteria populations and their relationships with environmental parameters

    Get PDF
    A survey in 16 activated sludge waste water treatment plants (WWTP) was conducted to contribute to the knowledge of the environmental parameters that determine the composition of the filamentous community. A total of 128 samples of mixed liquor from municipal WWTP were collected during 2 years, and 22 filamentous morphotypes were identified. The most frequent and abundant filamentous bacteria were, in both cases and by this order, type 0041/0675, type 0092, Microthrix parvicella and 1851, nocardioforms and Haliscomenobacter hydrossis. Concerning dominance, type 1851 was the most frequently dominant morphotype, followed by M. parvicella and types 0092 and 0041/0675. These were also, and by this order, the dominant morphotypes during bulking occurrences. Significant correlations were obtained between the abundance of filamentous bacteria and environmental parameters, but multivariate statistical analysis only confirmed the correlation between type 0092 and Sludge Volume Index (SVI), emphasizing the association of this filament with bulking. The discussion of the results in light of published works was complicated by the random use of terms such as frequency, abundance, and dominance with different and often unclear meanings. This reinforces the need of clarifying these terms when discussing the causes of filamentous overgrowth in WWTP.Portuguese Foundation for Science and Technology (FCT) and the European Community fund FEDER, through Program COMPETE, in the ambit of the Projects FCOMP-01-0124-FEDER-007025 (PTDC/AMB/68393/2006), PEst-OE/EQB/LA0023/2013, RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), and the Project BBioEnv - Biotechnology and Bioengineering for a sustainable world,REF. NORTE-07-0124- FEDER-000048, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. PhD grant SFRH/BD/64848/200

    Global networks, cities and economic performance: Observations from an analysis of cities in Europe and the USA

    Get PDF
    The network paradigm has been highly influential in spatial analysis in the globalisation era. As economies across the world have become increasingly integrated, so-called global cities have come to play a growing role as central nodes in the networked global economy. The idea that a city’s position in global networks benefits its economic performance has resulted in a competitive policy focus on promoting the economic growth of cities by improving their network connectivity. However, in spite of the attention being given to boosting city connectivity little is known about whether this directly translates to improved city economic performance and, if so, how well connected a city needs to be in order to benefit from this. In this paper we test the relationship between network connectivity and economic performance between 2000 and 2008 for cities with over 500,000 inhabitants in Europe and the USA to inform European policy

    Women's leadership in the Asian Century: does expansion mean inclusion?

    Get PDF
    This paper draws on British Council commissioned research in response to concerns about women's absence from senior leadership positions in higher education in South Asia. The study sought existing knowledge from literature, policies, and available statistics and collected original interview data from 30 academics in Afghanistan, Bangladesh, India, Nepal, Pakistan, and Sri Lanka. A central finding was that gender is not a category of analysis in higher education policy, research or statistical data in the region. Our interview data suggest that leadership was frequently not an object of desire for women. Being associated with particular types of masculinities, leadership often carried a heavy affective load for those women who transgressed patriarchal socio-cultural norms and disrupted the symbolic order of women being led by men. Leadership was frequently perceived and experienced by women in terms of navigating a range of ugly feelings and toxicities that depleted aspirations, well-being and opportunities
    corecore