How carbon pricing changes the relative competitiveness of low-carbon baseload generating technologies

There is wide public debate about which electricity generating technologies will best be suited to reduce greenhouse gas emissions (GHG). Sometimes this debate ignores real-world practicalities and leads to over-optimistic conclusions. Here we define and apply a set of fit-for-service criteria to identify technologies capable of supplying baseload electricity and reducing GHGs by amounts and within the timescale set by the Intergovernmental Panel on Climate Change (IPCC). Only five current technologies meet these criteria: coal (both pulverised fuel and integrated gasification combined cycle) with carbon capture and storage (CCS); combined cycle gas turbine with CCS; Generation III nuclear fission; and solar thermal backed by heat storage and gas turbines. To compare costs and performance, we undertook a meta-review of authoritative peer-reviewed studies of levelised cost of electricity (LCOE) and life-cycle GHG emissions for these technologies. Future baseload electricity technology selection will be influenced by the total cost of technology substitution, including carbon pricing, which is synergistically related to both LCOE and emissions. Nuclear energy is the cheapest option and best able to meet the IPCC timetable for GHG abatement. Solar thermal is the most expensive, while CCS will require rapid major advances in technology to meet that timetable.     

Are emissions of black carbon from gasoline vehicles underestimated? Insights from near and on-road measurements

Measurements of black carbon (BC) with a high-sensitivity laser-induced incandescence (HS-LII) instrument and a single particle soot photometer (SP2) were conducted upwind, downwind, and while driving on a highway dominated by gasoline vehicles. The results are used with concurrent CO(2) measurements to derive fuel-based BC emission factors for real-world average fleet and heavy-duty diesel vehicles separately. The derived emission factors from both instruments are compared, and a low SP2 bias (relative to the HS-LII) is found to be caused by a BC mass mode diameter less than 75 nm, that is most prominent with the gasoline fleet but is not present in the heavy-duty diesel vehicle exhaust on the highway. Results from both the LII and the SP2 demonstrate that the BC emission factors from gasoline vehicles are at least a factor of 2 higher than previous North American measurements, and a factor of 9 higher than currently used emission inventories in Canada, derived with the MOBILE 6.2C model. Conversely, the measured BC emission factor for heavy-duty diesel vehicles is in reasonable agreement with previous measurements. The results suggest that greater attention must be paid to black carbon from gasoline engines to obtain a full understanding of the impact of black carbon on air quality and climate and to devise appropriate mitigation strategies.     

Thermal stabilization of austenite in a high-nickel steel

The kinetics of the thermal stabilization of austenite have been studied in a 0.5 pct C 19 pct Ni steel within the range +300°C to -78°C. The Kinsman-Shyne model for stabilization is seen to be inadequate outside the temperature range +150°C to -20°C for this alloy. Stabilization at subzero temperatures can exhibit thermal reversibility without, however, requiring the fundamental mechanism itself to be similarly reversible. Formerly Research Student, Department of Metallurgy, University of Sheffield.     

Optimization of Investments in the Resilience of Water Distribution Systems Subject to Interruptions

In this paper, we propose an optimization model to support decisions related to the design of water distribution systems (WDS) that are subjected to interruptions caused by disruptive events, emphasizing their resilience capabilities, namely: absorption, adaptation, and recovery. Considering the exposure of WDS operation to random interruptions, we aim at minimizing the total investment considering the possibility of implementing actions that improve these capabilities, which can be put in place prior or posterior to the occurrence of a disruptive event. An application example is discussed as a way to understand the nature of the problem and to support the formulation of the proposed model. The results demonstrate the need to invest in resilient capacities adequate to each interruption probability associated to the disruptive scenarios, characterizing these considerations as of great importance to support managerial decisions, thus constituting a guideline for the allocation of investments before and/or after the occurrence of the event.

     

Oxidizable coupling agents: Introduction of surface functionality

The synthesis and grafting to glass or quartz of alkylalkoxysilane coupling agents (RSi(OR′) 3 ) that are susceptible/responsive to oxidation is described. Hydrosilylation of the inexpensive polyolefin squalene occurred efficiently once or twice with the silane HMe 2 SiOSiMe 2 (CH 2 ) 2 Si(OEt) 3 to give a silane coupling agent 3 that possesses several alkene groups. Once grafted to a silica surface Q-Sq using traditional means, the coupling agent was oxidized and further processed in several different ways. First, epoxidation using soluble peracids led to polyepoxides that could be further hydrolyzed to give polyalcohol surfaces Q-Sq-PAA-H 2 O . Alternatively, ozonolysis with gaseous O 3 led to the ozonides Q-Sq-O 3 , which could be decomposed to give either aldehyde/ketone Q-Sq-O 3 -redu , or ketone/carboxylic acid groups Q-Sq-O 3 -H 2 O 2 , respectively, bound to the surface. The aldehyde/ketone groups were characterized by condensation with dinitrophenylhydrazine to give the highly colored hydrazones Q-Sq-O 3 -redu-DNPH . These studies demonstrate the ready portability of organic chemistry to silica (or related) surfaces using judiciously chosen silane coupling agents and the possibility of controlling surface functionalization by postgrafting oxidation.     

Surface Preparation and Porosity in Electrodeposited Nickel

The porosity of electrodeposited nickel has been measured by an autoradiographic technique after the surface of the copper basis had been prepared by a number of different methods. Statistical analysis of the results shows that porosity is independent of the method of preparation.     

Complicated, complex, and compliant: best practice in obstetrics

In this study, the distinction between complicated and complex is used to shed some light on compliance with best practice guidelines. Data were gathered related to obstetric practice in labor wards and operating theaters at two Scandinavian hospitals, one of them being a university hospital, and in a training facility. The complexity of obstetrical intervention is analyzed in this paper, as is the potential of compliance-based routines in obstetrics. Complex situations are different from complicated ones and patient safety management efforts should recognize and enhance the sort of diversity that helps the emergence of resilience in complex situations.     

Timing and severity of immunizing diseases in rabbits is controlled by seasonal matching of host and pathogen dynamics

Infectious diseases can exert a strong influence on the dynamics of host populations, but it remains unclear why such disease-mediated control only occurs under particular environmental conditions. We used 16 years of detailed field data on invasive European rabbits (Oryctolagus cuniculus) in Australia, linked to individual-based stochastic models and Bayesian approximations, to test whether (i) mortality associated with rabbit haemorrhagic disease (RHD) is driven primarily by seasonal matches/mismatches between demographic rates and epidemiological dynamics and (ii) delayed infection (arising from insusceptibility and maternal antibodies in juveniles) are important factors in determining disease severity and local population persistence of rabbits. We found that both the timing of reproduction and exposure to viruses drove recurrent seasonal epidemics of RHD. Protection conferred by insusceptibility and maternal antibodies controlled seasonal disease outbreaks by delaying infection; this could have also allowed escape from disease. The persistence of local populations was a stochastic outcome of recovery rates from both RHD and myxomatosis. If susceptibility to RHD is delayed, myxomatosis will have a pronounced effect on population extirpation when the two viruses coexist. This has important implications for wildlife management, because it is likely that such seasonal interplay and disease dynamics has a strong effect on long-term population viability for many species.     

Biomimetic synthesis of gold nanocrystals using a reducing amphiphile

The first synthesis of a chelating and reactive surfactant derived from citric acid and a short silicone as hydrophobic tail is described. Aqueous solutions of this reactive amphiphile spontaneously induce gold ion reduction, particle nucleation, and further direct crystal growth. The process, both pH and light dependent, occurs through lipid-directed assembly of metal ions, their reduction and subsequent lipid-directed growth to yield ultrathin (approximately 7 nm thick) quasi two-dimensional gold nanocrystals.