Chromium evaporation and oxidation characteristics of alumina-forming austenitic stainless steels for balance of plant applications in solid oxide fuel cells

The chromium (Cr) evaporation behavior of several different types of iron (Fe)-based AFA alloys and benchmark Cr₂O₃-forming Fe-based 310 and Ni-based 625 alloys was investigated for 500 h exposures at 800 °C to 900 °C in air with 10% H₂O. The Cr evaporation rates from alumina-forming austenitic (AFA) alloys were ~5 to 35 times lower than that of the Cr₂O₃-forming alloys depending on alloy and temperature. The Cr evaporation behavior was correlated with extensive characterization of the chemistry and microstructure of the oxide scales, which also revealed a degree of quartz tube Si contamination during the test. Long-term oxidation kinetics were also assessed at 800 to 1000 °C for up to 10,000 h in air with 10% H₂O to provide further guidance for SOFC BOP component alloy selection.     

Nature and etiology of hollow-organ abdominal injuries in frontal crashes

Injuries to the hollow organs of the lower digestive system carry substantial risk of complication due to infection and blood loss, and commonly require invasive abdominal surgery to diagnose and treat. The causes of, and risk factors for, lower abdomen injury in automobile collisions are poorly understood. The goal of this study was to investigate the risk factors and potential mechanisms of hollow-organ, lower abdomen injury in belted automobile occupants in frontal collisions.     

Long Non-Coding RNAs as Master Regulators in Cardiovascular Diseases

Cardiovascular disease is the leading cause of death in the United States, accounting for nearly one in every seven deaths. Over the last decade, various targeted therapeutics have been introduced, but there has been no corresponding improvement in patient survival. Since the mortality rate of cardiovascular disease has not been significantly decreased, efforts have been made to understand the link between heart disease and novel therapeutic targets such as non-coding RNAs. Among multiple non-coding RNAs, long non-coding RNA (lncRNA) has emerged as a novel therapeutic in cardiovascular medicine. LncRNAs are endogenous RNAs that contain over 200 nucleotides and regulate gene expression. Recent studies suggest critical roles of lncRNAs in modulating the initiation and progression of cardiovascular diseases. For example, aberrant lncRNA expression has been associated with the pathogenesis of ischemic heart failure. In this article, we present a synopsis of recent discoveries that link the roles and molecular interactions of lncRNAs to cardiovascular diseases. Moreover, we describe the prevalence of circulating lncRNAs and assess their potential utilities as biomarkers for diagnosis and prognosis of heart disease.     

Indicators of Small Town Tourism Development Potential: The Case of Fouriesburg, South Africa

As small towns experience economic and social restructuring, many are pursuing tourism opportunities as one component of a more diversified local economic strategy. This paper is interested in the small town of Fouriesburg in South Africa's Free State. While the town was once a thriving service center for a surrounding rural agricultural region, this traditional economy has faded. Given that the nearby town of Clarens has developed a substantial tourism economy, we pose the question of whether there already exist indicators that Fouriesburg may be poised for a similar change. These indicators include location within the urban field, timing within the tourist area life cycle model, differentials/opportunities in property values, and the role of real estate agents as “gatekeepers” in directing investments. The findings suggest that, while Fouriesburg has potential for developing a tourism-oriented economy, many of the important policy and planning supports needed to assist with diversification are not yet in place.

Learning from the extreme River Tyne flood in January 2005

Extreme floods often demonstrate unanticipated characteristics that pose problems for management and response. The floods on the Tyne and Eden in January 2005 provided numerous examples of such unexpected response. This paper describes characteristics of storm rainfall and runoff generation on the River Tyne catchment, flood effects and damage. Unusual aspects of hydrological behaviour are highlighted as a basis for assessing what lessons can be learned for flood risk management. These include problems associated with coincidence of extreme wind speeds and rainfall, the retarding influence of floodplain storage on flood wave travel time in extreme flows, the influence of critical storm duration on the severity of the resulting flood on headwaters and main river, and the variety of mechanisms of flood occurrence. The occurrence of such an extreme flood provides the opportunity to validate and enhance the review process of the Environment Agency's flood zone maps.     

Natural versus wastewater derived dissolved organic carbon: implications for the environmental fate of organic micropollutants

The interaction of organic micropollutants with dissolved organic carbon (DOC) can influence their transport, degradation and bioavailability. While this has been well established for natural organic carbon, very little is known regarding the influence of DOC on the fate of micropollutants during wastewater treatment and water recycling. Dissolved organic carbon-water partition coefficients (K_DOC) for wastewater derived and reference DOC were measured for a range of micropollutants using a depletion method with polydimethylsiloxane disks. For micropollutants with an octanol-water partition coefficient (log K_OW) greater than 4 there was a significant difference in K_DOC between reference and wastewater derived DOC, with partitioning to wastewater derived DOC over 1000 times lower for the most hydrophobic micropollutants. The interaction of nonylphenol with wastewater derived DOC from different stages of a wastewater and advanced water treatment train was studied, but little difference in K_DOC was observed. Organic carbon characterisation revealed that reference and wastewater derived DOC had very different properties due to their different origins. Consequently, the reduced sorption capacity of wastewater derived DOC may be related to their microbial origin which led to reduced aromaticity and lower molecular weight. This study suggests that for hydrophobic micropollutants (log K_OW > 4) a higher concentration of freely dissolved and thus bioavailable micropollutants is expected in the presence of wastewater derived DOC than predicted using K_DOC values quantified using reference DOC. The implication is that naturally derived DOC may not be an appropriate surrogate for wastewater derived DOC as a matrix for assessing the fate of micropollutants in engineered systems.     

The Struggle to Compete: From comparative to competitive advantage in Northern British Columbia

The social, economic, and political landscape of northern British Columbia (BC), Canada, has undergone considerable transformation since a recession in the early 1980s. From this, there is an emerging recognition of the need to move from an economy based upon comparative advantage to one embracing competitive advantage. The purpose of this paper, drawn from ongoing regional research, is twofold. First, we apply a rural lens to the regional planning and development literature, which highlights the significance of competitive advantage as a tool for regional rejuvenation. Second, we add to this dialogue by exploring the relevance and meaning of competitive advantage in the non-metropolitan setting of northern BC.     

Hydrochemistry and mercury cycling in a High Arctic watershed

Mass budgets for total mercury, major ions and nutrients were calculated for Amituk Lake, located on Cornwallis Island, Nunavut, Canada. Total mercury in two distinct snowpacks averaged 1.25 and 4.21 ng L(-1); the discharge-weighted concentration of influent streams averaged 0.76 ng L(-1). The recent and pre-industrial Hg(T) fluxes in atmospheric deposition to the catchment were estimated to be 0.57 and 0.23 microg m(-2) but through retention within the catchment and/or re-volatilization from the melting snowpack, these decreased by 69% in the lake inflow. The spring freshet was the prime conduit for transporting Hg(T) into Amituk Lake. Because of limited mixing of surface runoff with the lake water column during snowmelt, 59% of the Hg(T) input was directly discharged through the outflow, 16% entered the lake water column where concentrations increased from 0.23 to 0.33 ng L(-1) from June to August and 25% was deposited to the bottom sediments producing a sediment Hg(T) flux of 3.1 microg m(-2).     

Quantification of denitrification potential in carbonaceous trickling filters

Biofilm samples from a carbonaceous trickling filter (TF) were evaluated in bench scale reactors to determine their maximum potential denitrification rates. Intact, undisturbed biofilms were placed into 0.6 L bench-scale reactors filled with sterilized, primary clarifier effluent spiked with nitrate to a final concentration of 16-18 mg/L as N. Dissolved oxygen concentrations were maintained between 2 and 4 mg/L in the bulk aqueous phase. Nitrate loss from the reactors was monitored over a 5h period. Denitrification rates of 3.09-5.55 g-N/m(2)day were observed with no initial lag period. This suggests that the capacity for denitrification is inherent in the biofilm and that denitrification can take place even when oxygen is present in the bulk aqueous phase. There were no significant differences in denitrification rates per unit area of media (g-N/m(2)day) either between (a). experimental runs or (b). sampling locations over the trickling filter. This suggests that denitrification potentials are uniform over the entire volume of the full-scale TF. For wastewater treatment plants with TFs that currently nitrify downstream, this approach may be used to meet less stringent permitted discharge concentrations and may allow some facilities to postpone or eliminate construction of additional unit processes for denitrification.