Radar studies of the vertical distribution of insects migrating over southern Britain: the influence of temperature inversions on nocturnal layer concentrations

Insects migrating over two sites in southern UK (Malvern in Worcestershire, and Harpenden in Hertfordshire) have been monitored continuously with nutating vertical-looking radars (VLRs) equipped with powerful control and analysis software. These observations make possible, for the first time, a systematic investigation of the vertical distribution of insect aerial density in the atmosphere, over temporal scales ranging from the short (instantaneous vertical profiles updated every 15 min) to the very long (profiles aggregated over whole seasons or even years). In the present paper, an outline is given of some general features of insect stratification as revealed by the radars, followed by a description of occasions during warm nights in the summer months when intense insect layers developed. Some of these nocturnal layers were due to the insects flying preferentially at the top of strong surface temperature inversions, and in other cases, layering was associated with higher-altitude temperature maxima, such as those due to subsidence inversions. The layers were formed from insects of a great variety of sizes, but peaks in the mass distributions pointed to a preponderance of medium-sized noctuid moths on certain occasions

Bi-fuel SI engine model for analysis and optimization

The natural gas as an alternative fuel has economical and environmental benefits. Bi-fuel engines powered by gasoline and compressed natural gas (CNG) are an intermediate and alternative step to dedicated CNG engines. The conversion to bi-fuel CNG engine could be a short-term solution to air pollution problem in many developing countries. In this paper a mathematical model of a bi-fuel four-stroke spark ignition (SI) engine is presented for comparative studies and analysis. It is based on the two-zone combustion model, and it has the ability to simulate turbulent combustion. The model is capable of predicting the cylinder temperature and pressure, heat transfer, brake work , brake thermal and volumetric efficiency, brake torque, brake specific fuel consumption (BSFC), brake mean effective pressure (BMEP), concentration of CO2, brake specific CO (BSCO) and brake specific NOx (BSNOx). The effect of engine speed, equivalence ratio and performance parameters using gasoline and CNG fuels are analysed. The model has been validated by experimental data using the results obtained from a bi-fuel engine. The results show the capability of the model in terms of engine performance optimization and minimization of the emissions. The engine used in this study is a typical example of a modified bi-fuel engine conversion, which could benefit the researchers in the field

Exergy analysis of a Bi fuel Si engine

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.This paper characterizes the exergy (availability) analysis in the bi-fuel (CNG and gasoline) spark ignition engines. The engine is modeled using a quasi-dimensional (QD) two-zone thermodynamic analysis. The differential equations relating to the compression, combustion and the expansion are solved by an approximation method. The model includes the intake, exhaust processes and a turbulent combustion model. The engine model is capable of simulating the burn rate, and compared to the computational fluid dynamic (CFD) models is it considerably faster. The developed model is based upon the second law of thermodynamics, and exergy analysis terms. These terms includes thermo-mechanical availability, chemical availability, heat transfer availability, work availability, and the irreversible processes that are the source of destroyed availability. Finally, the effect of the availability, the first law of thermodynamics (FLT) and the second law of thermodynamics (SLT) efficiency of equivalence ratio, ignition time and engine speed are presented and discussed.dc201

A dedicated haem lyase is required for the maturation of a novel bacterial cytochrome c with unconventional covalent haem binding

In bacterial c-type cytochromes, the haem cofactor is covalently attached via two cysteine residues organized in a haem c-binding motif. Here, a novel octa-haem c protein, MccA, is described that contains only seven conventional haem c-binding motifs (CXXCH), in addition to several single cysteine residues and a conserved CH signature. Mass spectrometric analysis of purified MccA from Wolinella succinogenes suggests that two of the single cysteine residues are actually part of an unprecedented CX15CH sequence involved in haem c binding. Spectroscopic characterization of MccA identified an unusual high-potential haem c with a red-shifted absorption maximum, not unlike that of certain eukaryotic cytochromes c that exceptionally bind haem via only one thioether bridge. A haem lyase gene was found to be specifically required for the maturation of MccA in W. succinogenes. Equivalent haem lyase-encoding genes belonging to either the bacterial cytochrome c biogenesis system I or II are present in the vicinity of every known mccA gene suggesting a dedicated cytochrome c maturation pathway. The results necessitate reconsideration of computer-based prediction of putative haem c-binding motifs in bacterial proteomes

Performance of the combined zero degree calorimeter for CMS

The combined zero degree calorimeter (ZDC) is a combination of sampling quartz/tungsten electromagnetic and hadronic calorimeters. Two identical combined calorimeters are located in the LHC tunnel at CERN at the straight section 140 m on each side of the CMS interaction vertex and between the two beam pipes. They will detect very forward photons and neutrons. ZDC information can be used for a variety of physics measurements as well as improving the collision centrality determination in heavy-ion collisions. Results are presented for ZDC performance studies with the CERN SPS H2 test beam.The combined zero degree calorimeter (ZDC) is a combination of sampling quartz/tungsten electromagnetic and hadronic calorimeters. Two identical combined calorimeters are located in the LHC tunnel at CERN at the straight section ~140 m on each side of the CMS interaction vertex and between the two beam pipes. They will detect very forward photons and neutrons. ZDC information can be used for a variety of physics measurements as well as improving the collision centrality determination in heavy-ion collisions. Results are presented for ZDC performance studies with the CERN SPS H2 test beam

Preserving the palaeoenvironmental record in Drylands: Bioturbation and its significance for luminescence-derived chronologies

Luminescence (OSL) dating has revolutionised the understanding of Late Pleistocene dryland activity. However, one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been preserved intact, enabling their use as proxy indicators of past changes. This relies on stabilisation or burial soon after deposition and a mechanism to prevent any subsequent re-mobilisation. As well as a dating technique OSL, especially at the single grain level, can be used to gain an insight into post-depositional processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences. This paper explores the possible impact of bioturbation (the movement of sediment by flora and fauna) on luminescence derived chronologies from Quaternary sedimentary deposits in Texas and Florida (USA) which have both independent radiocarbon chronologies and archaeological evidence. These sites clearly illustrate the ability of bioturbation to rejuvenate ancient weathered sandy bedrock and/or to alter depositional stratigraphies through the processes of exhumation and sub-surface mixing of sediment. The use of multiple OSL replicate measurements is advocated as a strategy for checking for bioturbated sediment. Where significant OSL heterogeneity is found, caution should be taken with the derived OSL ages and further measurements at the single grain level are recommended. Observations from the linear dunes of the Kalahari show them to have no bedding structure and to have OSL heterogeneity similar to that shown from the bioturbated Texan and Florida sites. The Kalahari linear dunes could have therefore undergone hitherto undetected post-depositional sediment disturbance which would have implications for the established OSL chronology for the region

A Fuzzy Criticality Assessment System of Process Equipment for Optimized Maintenance Management.

yesIn modern chemical plants, it is essential to establish an effective maintenance strategy which will deliver financially driven results at optimised conditions, that is, minimum cost and time, by means of a criticality review of equipment in maintenance. In this article, a fuzzy logic-based criticality assessment system (FCAS) for the management of a local company’s equipment maintenance is introduced. This fuzzy system is shown to improve the conventional crisp criticality assessment system (CCAS). Results from case studies show that not only can the fuzzy logic-based system do what the conventional crisp system does but also it can output more criticality classifications with an improved reliability and a greater number of different ratings that account for fuzziness and individual voice of the decision-makers

Practising social justice: Community organisations, what matters and what counts

This thesis investigates the situated knowing-in-practice of locally-based community organisations, and studies how this practice knowledge is translated and contested in inter-organisational relations in the community services field of practices. Despite participation in government-led consultation processes, community organisations express frustration that the resulting policies and plans inadequately take account of the contributions from their practice knowledge. The funding of locally-based community organisations is gradually diminishing in real terms and in the competitive tendering environment, large nationally-based organisations often attract the new funding sources. The concern of locally-based community organisations is that the apparent lack of understanding of their distinctive practice knowing is threatening their capacity to improve the well-being of local people and their communities. In this study, I work with practitioners, service participants and management committee members to present an account of their knowing-in-practice, its character and conditions of efficacy; and then investigate what happens when this local practice knowledge is translated into results-based accountability (RBA) planning with diverse organisations and institutions. This thesis analyses three points of observation: knowing in a community of practitioners; knowing in a community organisation and knowing in the community services field of practices. In choosing these points of observation, the inquiry explores some of the relations and intra-actions from the single organisation to the institutional at a time when state government bureaucracy has mandated that community organisations implement RBA to articulate outcomes that can be measured by performance indicators. A feminist, performative, relational practice-based approach employs participatory action research to achieve an enabling research experience for the participants. It aims to intervene strategically to enhance recognition of the distinctive contributions of community organisations’ practice knowledge. This thesis reconfigures understandings of the roles, contributions and accountabilities of locally-based community organisations. Observations of situated practices together with the accounts of workers and service participants demonstrate how community organisations facilitate service participants’ struggles over social justice. A new topology for rethinking social justice as processual and practice-based is developed. It demonstrates how these struggles are a dynamic complex of iteratively-enfolded practices of respect and recognition, redistribution and distributive justice, representation and participation, belonging and inclusion. The focus on the practising of social justice in this thesis offers an alternative to the neo-liberal discourse that positions community organisations as sub-contractors accountable to government for delivering measurable outputs, outcomes and efficiencies in specified service provision contracts. The study shows how knowing-in-practice in locally-based community organisations contests the representational conception of knowledge inextricably entangled with accountability and performance measurement apparatus such as RBA. Further, it suggests that practitioner and service participant contributions are marginalised and diminished in RBA through the privileging of knowledge that takes an ‘expert’, quantifiable and calculative form. Thus crucially, harnessing local practice knowing requires re-imagining and enacting knowledge spaces that assemble and take seriously all relevant stakeholder perspectives, diverse knowledges and methods

Catalytic activity of biomass-supported Pd nanoparticles : influence of the biological component in catalytic efficacy and potential application in ‘green’ synthesis of fine chemicals and pharmaceuticals

AbstractFive gram negative and two gram positive bacterial strains known for their heavy metal tolerance or ability to reduce metal ions were coated with Pd(0) nanoparticles (NPs) via reduction of soluble Pd(II) ions under H2 following an initial uptake of PdCl42- without added electron donor ('biosorption'), where the gram negative strains had a ~5-fold greater capacity for Pd(II). Cupriavidis metallidurans accumulated Pd(II) exceptionally; the possibility of reduction to Pd(0) via an endogenous electron donor was not discounted. The initial rate of subsequent H2-mediated Pd(II) reduction correlated with the Pd(II) removed during biosorption (r2=0.9). TEM showed strain-specific variations of Pd-NPs. At a 1:3 loading of Pd:biomass the cell surfaces of Escherichia coli and Desulfovibrio desulfuricans showed uniform coverage with small NPs with the other strains showing larger aggregates. NPs made by the gram positive cells appeared larger than their gram negative counterparts. At a loading of 1:19 all were active catalysts in Cr(VI) reduction and in two Heck coupling reactions. BioPdE. coli and bioPdD. desulfuricans and bioPdA. oxydans were consistently the best and worst catalysts respectively. BioPdE. coli was further tested as a process catalyst according to industrial protocols in Heck and Suzuki coupling reactions. Laboratory and industrial tests (coupling of phenyl iodide and ethyl acrylate) gave 75% and 78% conversion to ethyl cinnamate, respectively. The biomaterial catalysed Heck and Suzuki reactions using bromoacetophenone and 4-bromoanisole (Heck) and 4-chloroanisole (Suzuki) but not 3-chlorotoluene. In accordance with known chemical catalysis the catalytic efficacy was related to electron-withdrawing substituents on the phenyl ring, with more than 90% conversion (Suzuki) using 4-bromobenzotrifluoride

Crossing borders: new teachers co-constructing professional identity in performative times

This paper draws on a range of theoretical perspectives on the construction of new teachers’ professional identity. It focuses particularly on the impact of the development in many national education systems of a performative culture of the management and regulation of teachers’ work. Whilst the role of interactions with professional colleagues and school managers in the performative school has been extensively researched, less attention has been paid to new teachers’ interactions with students. This paper highlights the need for further research focusing on the process of identity co-construction with students. A key theoretical concept employed is that of liminality, the space within which identities are in transition as teachers adjust to the culture of a new professional workplace, and the nature of the engagement of new teachers, or teachers who change schools, with students. The authors argue that an investigation into the processes of this co-construction of identity offers scope for new insights into the extent to which teachers might construct either a teacher identity at odds with their personal and professional values, or a more ‘authentic’ identity that counters performative discourses. These insights will in turn add to our understanding of the complex range of factors impacting on teacher resilience and motivation