The Effects of Sulfuric Acid on the Mechanical Properties of Ice Single Crystals

Ice single crystals of various orientations containing various concentrations of H2SO4 up to 11.5 ppm were cut from large pucks of laboratory-grown ice. Constant-strain-rate compression tests were performed on the doped ice crystals both at −20°C at an axial strain rate of 1 × 10−5 s−1 and at −10°C at 1 × 106 s−1. The stress–strain curves showed a linearly rising stress with increasing strain, followed by a sharply declining stress after reaching a peak. With further strain, the sharp decline in stress slowed. The tests clearly showed, for the first time, that this naturally occurring impurity dramatically decreases both the peak stress and the subsequent flow stress of ice single crystals. The decrease in the peak strength was related to the square root of the concentration of H2SO4 up to 11.5 ppm, suggesting that the solubility limit of H2SO4 in ice is at least 11.5 ppm. The sulfuric acid also appeared to increase the ductility of the ice. Preliminary examination of a doped ice single crystal by synchrotron X-ray topography suggested that sulfuric acid dramatically increases the grown-in dislocation density

Evaluation of "Citizens at the Heart: a Citizen Centred Approach to Tackling Hate Crime" project report

This report provides an evaluation of the 'Citizens at the Heart: A Citizen Centred Approach to Tackling Hate Crime' project, a two-year pilot project funded by the European Union's Rights, Equality and Citizenship Programme. The project comprised of two streams of work: "Communities Tackling Hate" and "Enhanced Options Model for victims". In line with Nottingham City's values of 'Nottingham Together' and 'More in Common', the aim of the project was to prevent and tackle hate crime in new and innovative ways, bringing together policing, the criminal justice system, voluntary sector, communities and other statutory services. In particular, the project used the five key areas of focus identified in the UK government’s action plan for tackling hate crime (2016, 2018): Preventing hate crime; Responding to hate crime in our communities; Increasing the reporting of hate crime; Improving support for the victims of hate crime; Building our understanding of hate crime. The evaluation of the project was funded by Nottingham City Council and Office of the Police and Crime Commissioner (with delivery through Nottinghamshire Police). This report outlines the key elements of the project, as well as the findings of the evaluation of the project

Evaluation of "Citizens at the Heart: a Citizen Centred Approach to Tackling Hate Crime" project - executive summary

'Citizens at the Heart: A Citizen Centred Approach to Tackling Hate Crime' was a two-year pilot project funded by the European Union’s Rights, Equality and Citizenship Programme. In line with Nottingham City's values of 'Nottingham Together' and 'More in Common', the aim of the project was to prevent and tackle hate crime in new and innovative ways, bringing together policing, the criminal justice system, voluntary sector, communities and other statutory services. The project used the five key areas of focus identified in the UK government’s action plan for tackling hate crime (2016, 2018): Preventing hate crime; Responding to hate crime in our communities; Increasing the reporting of hate crime; Improving support for the victims of hate crime; Building our understanding of hate crime

How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals

We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax–solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory. The variation of pour point temperature as a function of the overall wax concentration is quantitatively modelled using the idea that, for each overall wax concentration, the pour point occurs at a temperature at which a critical volume fraction ϕ* of wax crystals has precipitated. Close to the pour point temperature, extraction and examination of the wax crystals show they consist of polydisperse, irregularly-shaped platelets with axial ratios (h/d, where h is the plate thickness and d is the plate long dimension) in the range 0.005–0.05. It is found that the measured ϕ* values corresponding to the pour point transitions are weakly correlated with the wax crystal axial ratios (h/d) for all wax–solvent–PPD polymer combinations. These results indicate that the pour point transition occurs at a volume fraction larger than the value at which the volumes of rotation of the platelet crystals overlap, i.e., 2.5(h/d) < ϕ* < 11(h/d). PPD polymers work, in part, by increasing the wax crystal axial ratio (h/d), thereby increasing ϕ* and reducing the pour point temperature. Since the PPD's ability to modify the wax crystal shape relies on its adsorption to the crystal-solution surface, it is anticipated and observed experimentally that optimum PPD efficacy is correlated with the difference between the wax and the polymer solubility boundary temperatures. This finding and the mechanistic insight gained here provide the basis for a simple and rapid screening test to identify candidate species likely to be effective PPDs for particular wax systems

Turing’s Genius – Defining an apt microcosm

Alan Turing (1912–1954) is widely acknowledged as a genius. As well as codebreaking during World War II and taking a pioneering role in computer hardware design and software after the War, he also wrote three important foundational papers in the fields of theoretical computer science, artificial intelligence, and mathematical biology. He has been called the father of computer science, but he also admired by mathematicians, philosophers, and perhaps more surprisingly biologists, for his wide-ranging ideas. His influence stretches from scientific to cultural and even political impact. For all these reasons, he was a true polymath. This paper considers the genius of Turing from various angles, both scientific and artistic. The four authors provide position statements on how Turing has influenced and inspired their work, together with short biographies, as a starting point for a panel session and visual music performance

Turbulence and Cavitation Suppression by Quaternary Ammonium Salt Additives

We identify the physical mechanism through which newly developed quaternary ammonium salt (QAS) deposit control additives (DCAs) affect the rheological properties of cavitating turbulent flows, resulting in an increase in the volumetric efficiency of clean injectors fuelled with diesel or biodiesel fuels. Quaternary ammonium surfactants with appropriate counterions can be very effective in reducing the turbulent drag in aqueous solutions, however, less is known about the effect of such surfactants in oil-based solvents or in cavitating flow conditions. Small-angle neutron scattering (SANS) investigations show that in traditional DCA fuel compositions only reverse spherical micelles form, whereas reverse cylindrical micelles are detected by blending the fuel with the QAS additive. Moreover, experiments utilising X-ray micro computed tomography (micro-CT) in nozzle replicas, quantify that in cavitation regions the liquid fraction is increased in the presence of the QAS additive. Furthermore, high-flux X-ray phase contrast imaging (XPCI) measurements identify a flow stabilization effect in the region of vortex cavitation by the QAS additive. The effect of the formation of cylindrical micelles is reproduced with computational fluid dynamics (CFD) simulations by including viscoelastic characteristics for the flow. It is demonstrated that viscoelasticity can reduce turbulence and suppress cavitation, and subsequently increase the injector’s volumetric efficiency

Bilateral giant femoropopliteal artery aneurysms: a case report

<p>Abstract</p> <p>Introduction</p> <p>Popliteal artery aneurysms are the most common peripheral arterial aneurysms, and are frequently bilateral. Acute limb ischemia, rupture and compression phenomena can complicate these aneurysms when the diameter exceeds 2 cm.</p> <p>Case Presentation</p> <p>We report an 82-year-old male patient with two giant femoropopliteal aneurysms, 10.5 and 8.5 cm diameters, managed in our institution. Both aneurysms were resected and a polytetrafluoroethylene (PTFE) femoropopliteal interposition graft was placed successfully. Management and literature review are discussed.</p> <p>Conclusion</p> <p>We believe this is the first report in the medical literature of bilateral giant femoropopliteal aneurysms.</p

Mixed-linker approach in designing porous zirconium-based metal–organic frameworks with high hydrogen storage capacity

YesThree highly porous Zr(IV)-based metal–organic frameworks, UBMOF-8, UBMOF-9, and UBMOF-31, were synthesized by using 2,2′-diamino-4,4′-stilbenedicarboxylic acid, 4,4′-stilbenedicarboxylic acid, and combination of both linkers, respectively. The mixed-linker UBMOF-31 showed excellent hydrogen uptake of 4.9 wt% and high selectivity for adsorption of CO2 over N2 with high thermal stability and moderate water stability with permanent porosity and surface area of 2552 m2 g−1.University of Bath; Royal Society of Chemistry; Engineering and Physical Sciences Research Counci