Lead/zinc exploration update

For over three decades, the United Nations has been assisting developing countries to explore, promote and develop their mineral resources. By industry standards, its exploration achievements in terms of economic discoveries are regarded as excellent. This paper provides an update of those exploration activities for lead and zinc in Burkina Faso, Pakistan and Nepal. These three case studies were selected because they illustrate the diversity of the technical assistance provided by the United Nations, as well as the technical and economic success of its programmes.     

Analytical method using gas chromatography and ion trap tandem mass spectrometry for the determination of S-triazines and their metabolites in the atmosphere

Gas chromatography-ion trap detector (GC-ITD) was used to detect atmospheric triazines and their degradation products in the gaseous and particulate phases. Because triazines and their metabolites are expected to be present at very low concentrations and enclosed in the complex atmospheric matrix, the analytical method used was both highly selective and sensitive. These two properties were obtained by associating chromatography with ion trap tandem mass spectrometry (GC-ITD (MS/MS)). To develop this method, a comparison between the two ionization modes (electron impact and positive-chemical-ionisation) in single-MS was first conducted to choose the parent ions of the five target analytes, i.e. atrazine, desethylatrazine, deisopropylatrazine, terbuthylazine and desethylterbuthylazine. Then, a MS/MS method was optimised by parameters such as the radio frequency storage level and the collision-induced dissociation excitation voltage. Finally, a last step enabled the development of a calibrating program based on the quantification of daughter ions. With this analytical procedure, the detection limits varied between 0.8 and 15 pg m(-3) depending on the compounds under study. This method was tested with success for four atmospheric samples collected in Strasbourg (France) in which four of the five target compounds were detected.     

Cloudwater studies at a high elevation site in the Vosges Mountains (France)

Cloud and rainwater samples have been collected at a high elevation site in the Vosges Mountains. An automated collection system has been used to collect bulk cloudwater and small cloudwater droplets. Bulk cloudwater concentrations were up to 10 times more concentrated than rainwater concentrations. Small clouddroplets showed generally higher concentrations than bulk cloudwater. Nevertheless, the enrichment factors depend on the compounds under study and appear to be related to the composition of the cloud condensation nuclei forming small or large clouddroplets. Principal component analysis and factor analysis were applied to the collected datasets and confirmed the influence of the cloud condensation nuclei on the composition difference between small and large cloudwater droplets.     

Assessment of Tree Rings as a Hydrologic Record in a Humid Subtropical Environment1

Crockett, Kris, Jonathan B. Martin, Henri D. Grissino-Mayer, Evan R. Larson, and Thomas Mirti, 2010. Assessment of Tree Rings as a Hydrologic Record in a Humid Subtropical Environment. Journal of the American Water Resources Association (JAWRA) 1-13. DOI: 10.1111/j.1752-1688.2010.00464.x Abstract: Information about long-term variability of streamflow is important to allocate water resources, but few historical records extend more than 75 years into the past, requiring proxy records to evaluate flow prior to that time. Flow proxies have been found in tree-ring widths in temperate regions, but have rarely been used in humid subtropical environments because the relationship between tree growth and climate was believed to be weakened by limited seasonality and stress on tree growth from drought conditions. Tree-ring residual chronologies from two forests sampled from northern Florida correlate well with historical annual discharge (r² values as high as 0.47) from 3 of 15 river-gauging stations that were used to compare with the tree-ring chronologies. The best correlations occur where streamflow has little contribution from spring discharge or continuous flow from lakes and wetlands. Streams lack correlations with the tree-ring residual chronologies (r² values as low as 0.0002) where springs and continuous discharge from lakes mute variations in their flow. Tree-ring chronologies appear to be useful for reconstruction of prehistorical variations of some streamflow in humid subtropical regions, but interpretations of the reconstructions must consider the local hydrologic conditions.     

UASB反应器处理造纸废水不同高度的污泥特性

为探讨上向流污泥床（UASB）反应器不同高度处的污泥特性,研究了生产性UASB反应器（总高7.2m）处理造纸废水时不同高度的污泥外观形态、稳定性及其产甲烷活性.结果显示,VS、TS、VSS、TSS浓度随着在反应器中取样高度的增加逐渐降低,并在距离反应器底部2.20m高度处出现分层.反应器1.20m和3.45m高度处的溶解性COD值较大（900mg·L-1以上）.反应器1.20m处污泥的稳定性较好（VS/TS较低）,固体浓度较高（TS136g·L-1,VS75g·L-1）,产甲烷活性较高（0.16g·g-1·d-1,以每gVSS中的COD计）,颗粒较大（平均当量直径为308μm）.UASB反应器处理造纸废水不同高度的污泥颗粒外观形态虽有差异,但污泥的生物活性近似.     

Comprehensive primary particulate organic characterization of vehicular exhaust emissions in France

A study to characterize primary particulate matter (PM_2.5 and PM₁₀) from the French vehicular fleet was conducted during winter 2008, in a tunnel in Marseille, France. The carbonaceous fraction represents 70% of the aerosol mass and elemental carbon fraction (EC) represent 60% of the carbonaceous fraction. The organic carbon OC was characterized in term of its water soluble fraction, functionalization rate and HULIS content. Seventy trace organic compounds including alkanes, polycyclic aromatic hydrocarbons (PAH), petroleum biomarkers and carboxylic acids were also quantified, in order to determine an organic emission profile for chemical mass balance modeling studies. Such source profiles were still missing in Europe and particularly in France. The profile obtained in this study is consistent with profiles determined in tunnel or dynamometer studies performed in other countries during the last ten years. These results suggest that organic compounds profiles from vehicular exhaust emissions are not significantly influenced by the geographic area and are thus suitable for use in aerosol source apportionment modeling applied across extensive regions. The chemical profile determined here is very similar to those obtained for diesel emissions with high concentrations of EC relative to OC (EC/OC = 1.8) and low concentrations of the higher molecular weight PAH. These results are consistent with the high proportion of diesel vehicles in the French fleet (49%).     

Environmental performance indicators: an empirical study of Canadian manufacturing firms

The aim of this exploratory study is to examine the importance of measurement and use of environmental performance indicators (EPIs) within manufacturing firms. Two research questions are investigated: (i) To what extent are firm characteristics associated with the importance of measurement of various categories of EPIs? (ii) To what extent are firm characteristics associated with global and specific uses of EPIs? More specifically, this paper examines four uses of EPIs (i.e. to monitor compliance, to motivate continuous improvement, to support decision making, and to provide data for external reporting) as well as four characteristics of firms, namely environmental strategy, International Organization for Standardization (ISO) 14001 compliance, size, and ownership. This study contributes to the environmental management accounting literature by collecting and analyzing empirical evidence that provides a better understanding of the associations among firm characteristics and EPIs.     

Flood protection and endogenous sorting of households: the role of credit constraints

Human migration is increasingly seen as a promising climate change adaptation and flood risk reduction strategy. The purpose of this paper is to investigate how spatial differences in flood risk, due to differences in flood protection, reduce the mobility of vulnerable households through a credit constraint mechanism. Using an equilibrium model with two households types and endogenous sorting, we show how spatial differences in flood protection lead to clustering of vulnerable households in a risky region, in a real-world setting of common United States (US) flood zones. We find clustering effects of some size for flood zones with return periods of less than 30 years.     

Fragrant legs in Paysandisia archon males (Lepidoptera, Castniidae)

Paysandisia archon was accidentally introduced into Europe where it damages endemic and ornamental palms, also threatening the date palm from North Africa. Little was known about sex pheromones in the Castniidae day-flying moth before a recent paper that concluded on the absence of female sex pheromone in P. archon. A putative identification of a short-range male pheromone, present on fore- and hindwings, was reported. In this paper, we describe the original structure of the male androconia located on the tarsi of the mid-legs. The extracts of mid-legs were analysed by GC/MS and the chemical structure of the male androconia component was identified as E2,Z13-18:OH. After extraction in solvent, biological activity of the extracts was assessed by EAG. The chemistry and the morphology of the androconia reinforce the current classification of the Castniidae in the Cossoid/Sesioid assemblage and provide new information on the chemical ecology in day-flying Lepidoptera and suit the recent paper describing the courtship behaviour