Trend and Cycles in Coal and Oil Prices in the Long Run: A Schumpeterian Approach

We contribute to the task of identifying trends and cycles in energy prices by examining very long series of prices for coal and oil, going back to 1650 in the case of coal and 1859 in the case of oil. We find annual rates of increase in real price of greater than two percent are found for coal in one cycle, 1842 to 1897, and for oil in two cycles, 1897 to 1953 and 1953 to 2009. However, there is no noticeable change in coal prices for the earliest cycles, from 1675 to 1731 and 1731 to 1787, as well as a notable decline in the latest cycle, from 1953 to 2009. Also, oil prices decline from 1859 to 1897. Clearly, there is no unitary trend across coal and oil that would suggest a general failure of supply due to universal depletion of fossil fuels. Instead, the suggestion is that developments in technology are of critical importance. In particular, the shift in motive power from coal to oil is associated with a rise in the price of oil relative to coal and, in the most recent cycle, a trend decrease in the real coal price

Terms of trade movements and the global economic crisis: Implications for the Asia-Pacific region

Dramatic changes in the relative prices of goods in international trade have accompanied, and indeed preceded, the global crisis. These changes are reflected in the terms of trade ofindividual countries and in the relative prices of goods within those countries. Asia-Pacific countries are particularly affected by the changes in relative prices as they have been at the core of the increasing globalisation of production and distribution systems. An analysis of the causes and effects of the relative price changes is developed based on applying the analysisof business cycles developed by Joseph Schumpeter. Schumpeter's analysis emphasises innovation and structural change, particularly creative destruction, which impart uneven development on the economy and can foster financial crises. By applying Schumpeter's analysis the current crisis is put in the context of long-wave development of the capitalist system, which leads to predictions about the likely path of price and output changes over the medium term of the next decade or two

Towards greener lixiviants in value recovery from mine wastes: Efficacy of organic acids for the dissolution of copper and arsenic from legacy mine tailings

This is the author accepted manuscript. The final version is freely available from MDPI via the DOI in this recordIn many cases, it may be possible to recover value (e.g. metals, land) from legacy mine wastes and tailings when applying leaching-based remediation such as dump/heap leaching or in-vessel soil washing. However, if the lixiviant used has the potential to cause environmental damage upon leakage, then this approach will have limited practicability due to actual or perceived risk. This study focused on comparing the efficacy of organic acids, namely methanesulfonic (CH3SO3H) and citric (C6H8O7) acid, with mineral acids, namely sulfuric (H2SO4) and hydrochloric (HCl) acid, for the dissolution of Cu and As from mine tailings. The advantage of the former acid type is the fact that its conjungate base is readily biodegradable which should thereby limit the environmental impact of accidental spill/leakage (particularly in non-carbonate terrain) and might also be directly useful in capture/recovery systems coupled with percolation leaching (e.g., as an electron donor in sulphate-reducing bioreactors). The operational factors acid concentration, leaching time, mixing intensity and solid–liquid ratio, were tested in order to determine the optimum conditions for metal dissolution. HCl, H2SO4, and CH3SO3H typically exhibited a relatively similar leaching ability for As despite their different pKa values, with dissolutions of 58%, 56%, 55%, and 44% recorded for H2SO4, HCl, CH3SO3H, and C6H8O7, respectively, after 48 h when using 1 M concentrations and a 10:1 L:S ratio. For the same conditions, H2SO4 was generally the most effective acid type for Cu removal with 38% compared to 32%, 29% and 22% for HCl, CH3SO3H and C6H8O7. As such, CH3SO3H and C6H8O7 demonstrated similar performances to strong mineral acids and, as such, hold great promise as environmentally compatible alternatives to conventional mineral acids for metal recovery from ores and waste.The work was financially supported by the Natural Environment Research Council (grant number: NE/L013908/1)

Fossil rootlet biopores as conduits for contaminant transport through clay horizons: a case study of DNAPL behaviour in Severn alluvium, UK

This paper presents a case study of several DNAPL contaminated sites around the Severn Estuary (UK) where a combination of detailed observations, core dissections and physicochemical characterisation of alluvial clay–silt horizons have revealed the presence of fossil rootlet biopores which act and have the potential to act as conduits for contaminant migration through up to 13 m of clay–silt. The biopores are shown to penetrate the low-permeability (K ~ 10−10 m/s) clay–silt matrix throughout its entire depth (up to 13 m) and provide a preferential transport pathway for DNAPLs from near surface to the underlying aquifer, with particularly high concentrations measured in the biopores themselves. Capillary rise experiments with coal tar distillate demonstrate that DNAPLs are drawn into biopores, with values of surface interfacial tension for the system calculated as 8 × 10−2 J/m2. Wicking by residual plant fibres was demonstrated qualitatively and is thought to be an important additional transport mechanism. The DNAPL contamination below and throughout the Severn alluvial clay–silt horizons demonstrates that the assumption that these horizons act as an effective seal protecting underlying aquifers from severe pollution from the legacy sites around the Severn is flawed and highlights the failure of current protocols for sampling of clay horizons for hydraulic conductivity assessments, since current methods can destroy delicate in situ biopore structures. The study demonstrates that the interplay between ecological and the geological depositional environment can, at a regional scale, result in a network of biopores that can potentially act as conduits for contaminant transport

Selective formation of copper nanoparticles from acid mine drainage using nanoscale zerovalent iron particles

Nanoscale zerovalent iron (nZVI) has been investigated for the selective formation of Cu nanoparticles from acid mine drainage (AMD) taken from a legacy mine site in the UK. Batch experiments were conducted containing unbuffered (pH 2.67 at t=0) and pH buffered (pH 99.9% removal of all metals within 1 h when nZVI ≥1.0 g/L) from unbuffered AMD despite the coexistent of numerous other metals in the AMD, namely: Na, Ca, Mg, K, Mn and Zn. An acidic pH buffer enabled similarly high Cu removal but maximum removal of only <1.5% and <0.5% Cd and Al respectively. HRTEM-EDS confirmed the formation of discrete spherical nanoparticles comprised of up to 68% wt. Cu, with a relatively narrow size distribution (typically 20-100 nm diameter). XPS confirmed such nanoparticles as containing Cu0 , with the Cu removal mechanism therefore likely via cementation with Fe0 . Overall the results demonstrate nZVI as effective for the one-pot and selective formation of Cu0 -bearing nanoparticles from acidic wastewater, with the technique therefore potentially highly useful for the selective upcycling of dissolved Cu in wastewater into high value nanomaterials

Sorption and fractionation of rare earth element ions onto nanoscale zerovalent iron particles

The removal behaviour of rare earth element (REE), (Sc, Y, La-Lu), ions onto nanoscale zerovalent iron (nZVI) particles has been investigated. Batch sorption isotherms were conducted using REE-bearing acid mine drainage (AMD) and a range of different synthetic REE solutions, which were exposed to nZVI at 0.1-4.0 g/L. Maximum adsorption capacity of Yb and La was 410 and 61 mg/g respectively (1000 mg/L LaCl3 and YbCl3 starting concentration, initial pH=4.5, T=294 K), the highest currently reported in the literature. Aqueous REE removal to ultratrace concentrations (99.9% removal) was also recorded after 30 min (the first sampling interval) exposure of ≥0.5 g/L nZVI to 10 mg/L aqueous REE solutions (nitrate counterion). Similar rapidity and near-total removal ability was recorded for the exposure of nZVI to the AMD, however, a greater nZVI concentration was required, with the removal of all REEs (with the exception of La, Ce, Nd and Gd) to <1 µg/L when exposed to nZVI at 4.0g/L for 30 mins. In all systems nZVI was selective for the removal of HREE ions in preference to LREE ions, with the mechanism determined using HRTEM-EDS and XPS analysis as via surface mediated precipitation. Overall the results demonstrate nZVI as exhibiting great promise as an effective and versatile agent for simultaneous REE ion recovery and fractionation

Trend and cycle in primary commodity prices: A neo-Schumpeterian interpretation

This paper adapts Schumpeter's theory of economic development and the business cycle for the purpose of analysing movements in prices of primary commodities in both the short and long run. Schumpeter focuses his analysis on movements in prices of finished consumer goods, but he clearly recognizes that prices of primary products are both directly and indirectly affected by the same mechanism that drives finished goods prices. We extend Schumpeter's analysis by directly examining features of primary commodity production and consumption that are weakly developed by Schumpeter. We find that the extended analysis fits nicely to data on commodity prices over the period 1650 to 2008

Comparison of primers for the detection of Phytophthora (and other oomycetes) from environmental samples

Many oomycetes are important plant pathogens that cause devastating diseases in agricultural fields, orchards, urban areas, and natural ecosystems. Limitations and difficulties associated with isolating these pathogens have led to a strong uptake of DNA metabarcoding and mass parallel sequencing. At least 21 primer combinations have been designed to amplify oomycetes, or more specifically, Phytophthora species, from environmental samples. We used the Illumina sequencing platform to compare 13 primer combinations on mock communities and environmental samples. The primer combinations tested varied significantly in their ability to amplify Phytophthora species in a mock community and from environmental samples; this was due to either low sensitivity (unable to detect species present in low concentrations) or a lack of specificity (an inability to amplify some species even if they were present in high concentrations). Primers designed for oomycetes underestimated the Phytophthora community compared to Phytophthora-specific primers. We recommend using technical replicates, primer combinations, internal controls, and a phylogenetic approach for assigning a species identity to OTUs or ASVs. Particular care must be taken if sampling substrates where hybrid species could be expected. Overall, the choice of primers should depend upon the hypothesis being tested