The Tucson Mineral Show and the market for collector minerals: The potential for artisanal and small scale miners

Minerals that are sold to collectors are often produced by artisanal and small scale miners in many developing countries. The market for collector minerals is not well understood by most government agencies or NGOs but has a large impact on the artisanal and small miners that have the opportunity to produce these minerals because of the high prices that can be realized. This paper describes the collector mineral market that is held annually in Tucson, Arizona, that analyzes the competitive forces that affect the profitability of the mineral dealers at the show and describes potential methods for artisanal and small scale miners to participate successfully in the show. Most collector minerals produced by artisanal and small-scale miners are valued for their aesthetic qualities instead of mineral content. The 43 shows that operate during the first two weeks in February make up the largest gem and mineral show in the world, the Tucson Show. The Tucson Mineral Show is a subgroup of six shows that specialize primarily in collector minerals.There are several competitive forces at the Tucson Mineral Show that can affect the profit potential of dealers that participate in the show. These forces include potential entrants, suppliers, buyers, substitutes, and rivalry among existing competitors. New entrants face several barriers to entering the market place including the supply side economies of scale, demand side benefits of scale, and capital requirements. Because of these barriers, the cost of doing business and the way that promoters organize and manage the shows, it is difficult for artisanal and small scale miners to enter the show and compete with established dealers. However, with support from entities such as local governments, non-profit organizations, and international organizations the artisanal and small scale miners have the potential to have their minerals sold at the Tucson Shows for prices that would be greater than what can be achieved in the local market. Methods to help the artisanal and small scale miners compete include direct sales or consignments to retail dealers, tailgating, development of sales co-operatives, and the creation of an artisanal/small scale mineral show.     

Comparison of Marine and Terrestrial Protected Areas under Federal Jurisdiction in the United States

Abstract: There is a significant disparity in the protection of terrestrial and marine environments in the United States. Despite the considerable literature dedicated to the subject of protected areas, both terrestrial and marine, in the United States, we are not aware of work explicitly describing this dichotomy. We compared marine and terrestrial areas under federal jurisdiction to provide a quantitative assessment of the differences between the conservation of land and sea in the United States. Specifically, we compared national marine sanctuaries (including sanctuary preservation areas and ecological reserves) with national parks, national forests, and national wildlife refuges (including national wilderness preservation areas). Our results suggest that marine sanctuaries are fewer in number, smaller in total area, and smaller in percentage of area covered than are terrestrial protected areas.     

Connecting today's climates to future climate analogs to facilitate movement of species under climate change

Increasing connectivity is an important strategy for facilitating species range shifts and maintaining biodiversity in the face of climate change. To date, however, few researchers have included future climate projections in efforts to prioritize areas for increasing connectivity. We identified key areas likely to facilitate climate‐induced species’ movement across western North America. Using historical climate data sets and future climate projections, we mapped potential species’ movement routes that link current climate conditions to analogous climate conditions in the future (i.e., future climate analogs) with a novel moving‐window analysis based on electrical circuit theory. In addition to tracing shifting climates, the approach accounted for landscape permeability and empirically derived species’ dispersal capabilities. We compared connectivity maps generated with our climate‐change‐informed approach with maps of connectivity based solely on the degree of human modification of the landscape. Including future climate projections in connectivity models substantially shifted and constrained priority areas for movement to a smaller proportion of the landscape than when climate projections were not considered. Potential movement, measured as current flow, decreased in all ecoregions when climate projections were included, particularly when dispersal was limited, which made climate analogs inaccessible. Many areas emerged as important for connectivity only when climate change was modeled in 2 time steps rather than in a single time step. Our results illustrate that movement routes needed to track changing climatic conditions may differ from those that connect present‐day landscapes. Incorporating future climate projections into connectivity modeling is an important step toward facilitating successful species movement and population persistence in a changing climate.     

Aerosol entrainment from a sparged non-Newtonian slurry

Previous bench-scale experiments have provided data necessary for the development of empirical models that describe aerosol entrainment from bubble bursting. However, previous work has not been extended to non-Newtonian liquid slurries. Design of a waste treatment plant on the Hanford Site in Washington required an evaluation of the applicability of these models outside of their intended range. For this evaluation, aerosol measurements were conducted above an air-sparged mixing tank filled with simulated waste slurry possessing Bingham plastic rheological properties. Three aerosol-size fractions were measured at three sampling heights and for three different sparging rates. The measured entrainment was compared with entrainment models. One model developed based on bench-scale air-water experiments agreed well with measured entrainment. Another model did not agree well with the measured entrainment. It appeared that the source of discrepancy between measured and modeled entrainment stemmed from application beyond the range of data used to develop the model. A possible separation in entrainment coefficients between air-water and steam-water systems was identified. A third entrainment model was adapted to match experimental conditions and fit a posteri to the experimental data, resulting in a modified version that resulted in estimated entrainment rates similar to the first model.     

A longitudinal assessment of the aquatic macroinvertebrate community in the channelized lower Missouri River

We conducted an aquatic macroinvertebrate assessment in the channelized reach of the lower Missouri River, and used statistical analysis of individual metrics and multimetric scores to identify community response patterns and evaluate relative biological condition. We examined longitudinal site differences that are potentially associated with water qualityrelated factors originating from the Kansas City metropolitan area, using data from coarse rock substrate in flowing water habitats (outside river bends), and depositional mud substratein slack water habitats (dike fields). Three sites above rivermile (RM) 369 in Kansas City (Nebraska City, RM = 560; St. Joseph, RM = 530; Parkville, RM = 377) and three below (Lexington, RM = 319; Glasgow, RM = 228; Hermann, RM = 94) were sampled with rock basket artificial substrates, a qualitative kicknet method, and the Petite Ponar. We also compared the performance of the methods used. A total of 132 aquatic macroinvertebrate taxa were collected from the lower Missouri River; one third of these taxa belonged to the sensitiveEPOT insect orders (Ephemeroptera, Plecoptera, Odonata, and Trichoptera). Rock baskets had the highest mean efficiency (34.1%) of the methods, and the largest number of taxa was collected by Ponar (n = 69) and kicknet (n = 69) methods. Seven of the 15 metrics calculated from rock basket data, and five ofthe nine metrics calculated from Ponar data showed highly significant differences (ANOVA, P < 0.001) at one or more sitesbelow Kansas City. We observed a substantial reduction in net-spinning Trichoptera in rock habitats below Kansas City (Lexington), an increase in relative dominance of Oligochaeta in depositional habitats at the next site downstream (Glasgow), and lower relative condition scores in rock habitat at Lexingtonand depositional habitat at Glasgow. Collectively, these data indicate that some urban-related impacts on the aquatic macroinvertebrate community are occurring. Our results suggest that the methods and assessment framework we used in this studycould be successfully applied on a larger scale with concurrentwater and sediment chemistry to validate metrics, establish impairment levels, and develop a specific macroinvertebrate community index for the lower Missouri River. We recommend accomplishing this with longitudinal multi-habitat sampling at a larger number of sites related to all potential sources of impairment, including major tributaries, urban areas, and point sources.     

downscaling procedures as a tool for integration of multiple air issues

In assessing the risks associated with climate change,downscaling has proven useful in linking surfacechanges, at scales relevant to decision making, tolarge-scale atmospheric circulation derived from GCMoutput. Stochastic downscaling is related to synopticclimatology, weather-typing approaches (classifyingcirculation patterns) such as the Lamb Weather Typesdeveloped for the United Kingdom (UK), the EuropeanGrosswetterlagen (Bardossy and Plate, 1992) and thePerfect Prognosis (Perfect Prog) method from numericalweather prediction. The large-scale atmosphericcirculation is linked with site-specific observationsof atmospheric variables, such as precipitation, windspeed or temperature, within a specified region. Classifying each day by circulation patterns isachieved by clustering algorithms, fuzzy rule bases,neural nets or decision trees. The linkages areextended to GCM output to account for climate change. Stochastic models are developed from the probabilitydistributions for extreme events. Objective analysiscan be used to interpolate values of these models toother locations. The concepts and some applicationsare reviewed to provide a basis for extending thedownscaling approach to assessing the integrated riskof the six air issues: climate change, UV-B radiation,acid rain, transport of hazardous air pollutants, smogand suspended particulates.     

Effect of specimen size and grain size on deformation in microextrusion

Miniaturization of systems and devices continues unabated, which in turn requires the production of microscale components. Similar to the macroscale process, microextrusion provides a means to fabricate metallic micropins having characteristic dimensions on the order of 1 mm or less with a lower-cost, high-throughput process. In this paper, the effect of the specimen size and grain size on deformation during microextrusion is investigated. Microhardness, microstructure, and X-ray texture analyses show that when the grain size becomes comparable to the specimen feature size, together with miniaturization, penetration of the shear deformation occurs. As a result, the coarse-grained structure has higher hardness than the fine-grained structure, especially in the central regions of the cross-section for the two smallest size extrusion cases investigated, which have Ø0.76/0.57 mm and Ø1.5/1.0 mm dimensions before and after extrusion, respectively. For the largest size extrusion case investigated, Ø2.0/1.33 mm pins, the coarse-grained structure has a lower hardness than the fine-grained one, which is typical for macroscale processes and consistent with the Hall–Petch relationship.