Liquid-Solid Transition of Hard Spheres Under Gravity

We investigate the liquid-solid transition of two dimensional hard spheres in the presence of gravity. We determine the transition temperature and the fraction of particles in the solid regime as a function of temperature via Even-Driven molecular dynamics simulations and compare them with the theoretical predictions. We then examine the configurational statistics of a vibrating bed from the view point of the liquid-solid transition by explicitly determining the transition temperature and the effective temperature, T, of the bed, and present a relation between T and the vibration strength.Comment: 14 total pages, 4 figure

Non-antibiotic pharmaceuticals are toxic against <i>Escherichia coli</i> with no evolution of cross-resistance to antibiotics

Antimicrobial resistance can arise in the natural environment via prolonged exposure to the effluent released by manufacturing facilities. In addition to antibiotics, pharmaceutical plants also produce non-antibiotic pharmaceuticals, both the active ingredients and other components of the formulations. The effect of these on the surrounding microbial communities is less clear. We aimed to assess whether non-antibiotic pharmaceuticals and other compounds produced by pharmaceutical plants have inherent toxicity, and whether long-term exposure might result in significant genetic changes or select for cross-resistance to antibiotics. To this end, we screened four non-antibiotic pharmaceuticals (acetaminophen, ibuprofen, propranolol, metformin) and titanium dioxide for toxicity against Escherichia coli K-12 MG1655 and conducted a 30 day selection experiment to assess the effect of long-term exposure. All compounds reduced the maximum optical density reached by E. coli at a range of concentrations including one of environmental relevance, with transcriptome analysis identifying upregulated genes related to stress response and multidrug efflux in response ibuprofen treatment. The compounds did not select for significant genetic changes following a 30 day exposure, and no evidence of selection for cross-resistance to antibiotics was observed for population evolved in the presence of ibuprofen in spite of the differential gene expression after exposure to this compound. This work suggests that these compounds, at environmental concentrations, do not select for cross-resistance to antibiotics in E. coli

A barrier and techno-economic analysis of small-scale bCHP (biomass combined heat and power) schemes in the UK

bCHP (Biomass combined heat and power) systems are highly efficient at smaller-scales when a significant proportion of the heat produced can be effectively utilised for hot water, space heating or industrial heating purposes. However, there are many barriers to project development and this has greatly inhibited deployment in the UK. Project viability is highly subjective to changes in policy, regulation, the finance market and the low cost fossil fuel incumbent. The paper reviews the barriers to small-scale bCHP project development in the UK along with a case study of a failed 1.5MWel bCHP scheme. The paper offers possible explanations for the project's failure and suggests adaptations to improve the project resilience. Analysis of the project's: capital structuring contract length and bankability; feedstock type and price uncertainty, and plant oversizing highlight the negative impact of the existing project barriers on project development. The research paper concludes with a discussion on the effects of these barriers on the case study project and this industry more generally. A greater understanding of the techno-economic effects of some barriers for small-scale bCHP schemes is demonstrated within this paper, along with some methods for improving the attractiveness and resilience of projects of this kind

Fundemental tests for two and three dimensional, small strain, elastoplastic finite element analysis

SIGLEAvailable from British Library Document Supply Centre- DSC:q93/18439 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Coupled Mach--Zehnder interferometer

InGaAsP photonic integrated circuit. The system acts as an optical flip-flop, with optical set and reset functions. A schematic diagram of the device is shown in Fig. 1. Each MZI in the device is constructed from the following components: a 72 / 28 splitting ratio multimode interference coupler 6 at the MZI input (left side of Fig. 1), a 1450 #m long electro-optic phase shifter (PS) in one MZI arm, 7 a 750 #m long SOA in the other MZI arm, and, following the SOA, another 72 / 28 multimode interference coupler. This coupler is employed to couple light out of the system, such that the system&apos;s state can be observed, and also to couple in light that is used to switch between states. The two MZIs share a common 50 / 50 multimode interference coupler. The couplers employ tapered access waveguides for accurate coupling ratios and low excess loss. 8 A theory on the way in which two coupled MZIs can interact to form a 1 bit memory is given in Ref. 5. Here, MZI 1 and MZI 2 share a co