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151.
In sub-Saharan Africa, artisanal and small-scale mining (ASM) has caused a range of environmental, social and economic problems. Most of the donor support pledged to improve conditions in the sector to date, however, has failed to facilitate marked improvements, in large part because emphasis has been placed on technical interventions; at the same time, impoverished miners’ needs and concerns have been seriously overlooked. It is against this background that this paper critically examines the underpinnings and potential of “Fair Trade gold” as a solution to many of the problems plaguing the ASM sector and a mechanism for alleviating the hardships of its operators. Unlike the majority of ASM-support support measures implemented in the past, “Fair Trade gold” is entrenched in the discourse of “partnership” and “participation”. To ensure its effectiveness initiatives must be adapted according to the specificities of ASM.  相似文献   
152.
Cut-off grade strategy (COGS) is a concept that directly influences the financial, technical, economical, and environmental issues in relation to the exploitation of a mineral resource. Despite the simple definition of cut-off grade, the COGS problem is one of the complex and complicated problems in the mine planning process. From the optimization point of view, the COGS with an objective of maximizing the present value of future cash flows is a non-linear and a non-convex problem that even in its deterministic form can be solved using approximate optimization methods. This optimization problem will also be more complex and complicated under uncertainty conditions. This paper proposes an uncertainty based multi-criteria ranking system to investigate the problem of COGS selection considering metal price and geological uncertainties. The proposed system aims at selection of the best COGS among technically feasible alternative COGSs under uncertainty circumstances. Our developed system is based on integrating metal price and geological uncertainties as well as operating flexibility to close the mine early. We incorporate this operating flexibility into the proposed system using a Monte Carlo based real options (RO) valuation model. For this purpose, in addition to the expected value, other risk criteria are considered to rank the alternatives. These risk criteria include abilities of strategies in producing extra profits, minimizing losses, and achieving the predefined goals of the production. In this study, the technically possible COGSs are generated using the Lane comprehensive algorithm. To demonstrate the effectiveness of the proposed system, we utilize data of an Iranian gold mine. Results show that the proposed system outperforms conventional methods in the sense that it shows significantly lower average mis-ranking than the other methods and also selects a strategy with a higher value. The sensitivity analysis of the proposed system relative to the gold price shows that the system is highly dependent on the parameters of the stochastic process used to model the evolution of the metal price. Therefore, special consideration should be given in estimating stochastic process parameters.  相似文献   
153.
The aim of this paper is to check the hypothesis for the environmental Kuznets curve for sulfur dioxide. This involved analysis of: 1. the theoretical basis of the model; 2. the technical problem of SO2 generation; 3 the kind of information used in the estimations; 4. changes in the structure of electric energy production; 5. improvements in energy efficiency; and 6. the recent introduction of cleaning mechanisms in a favourable political context. The conclusion is that, if it is possible to prove the existence of environmental Kuznets curve models, their utility as instruments of economic policy is debatable.  相似文献   
154.
Coal, like most materials found in nature, contains trace quantities of the naturally occurring primordial radionuclides, i.e. of 40K and of 238U, 232Th and their decay products. Therefore, the combustion of coal results in the released into the environment of some natural radioactivity (1.48 TBq y−1), the major part of which (99 %) escapes as very fine particles, while the rest in fly ash. The activity concentrations of natural radionuclides measured in coals originated from coal mines in Greece varied from 117 to 435 Bq kg−1 for 238U, from 44 to 255 Bq kg−1 for 226Ra, from 59 to 205 Bq kg−1 for 210Pb, from 9 to 41 Bq kg−1 for 228Ra (232Th) and from 59 to 227 Bq kg−1 for 40K. Fly ash escapes from the stacks of coal-fired power plants in a percentage of 3-1% of the total fly ash, in the better case. The natural radionuclide concentrations measured in fly ash produced and retained or escaped from coal-fired power plants in Greece varied from 263 to 950 Bq kg−1 for 238U, from 142 to 605 Bq kg−1 for 226Ra, from 133 to 428 Bq kg−1 for 210Pb, from 27 to 68 Bq kg−1 for 228Ra (232Th) and from 204 to 382 Bq kg−1 for 40K. About 5% of the total ash produced in the coal-fired power plants is used as substitute of cement in concrete for the construction of dwellings, and may affect indoor radiation doses from external irradiation and the inhalation of radon decay products (internal irradiation) is the most significant. The resulting normalized collective effective doses were 6 and 0.5 man-Sv (GW a)−1 for typical old and modern coal-fired power plants, respectively.  相似文献   
155.
Aggregates constitute the biggest branch of mining by production volume and the second in value, after the sector of fossil fuels. Their close connection with the construction industry places them among the most used materials worldwide, second only to water. Despite its significance, the sector suffers from the non-systematic register of production data, resulting in weakness to study the main features affecting the sector’s structure and future capacity. The paper focuses on the aggregates production in 26 European countries. Data from available sources are gathered and combined for a 10-year period (1997–2006), as an effort to provide a clear view of the major attributes of this vital industrial sector. Through a thorough analysis, the main drivers in aggregates production are revealed and existing correlations and trends are identified. New findings are also presented, for example the significance of GDP from construction and the strong connection of aggregates production per capita with the residential building sector.  相似文献   
156.
The political acceptability of climate policies is undermined by job-killing arguments, especially for the least-skilled workers. However, evidence of the distributional impacts for different workers remains scant. We examine the associations between climate policies, proxied by energy prices, and workforce skills for 14 European countries and 15 industrial sectors over the period 1995–2011. Using a shift-share instrumental variable estimator and controlling for the influence of automation and globalization, we find that climate policies have been skill biased against manual workers and have favoured technicians. The long-term change in energy prices accounted for between 9.2% and 17.5% (resp. 4.2% and 8.0%) of the increase (resp. decrease) in the share of technicians (resp. manual workers).  相似文献   
157.
Weather anomalies have a range of adverse contemporaneous impacts on health and socio-economic outcomes. This paper tests if temperature anomalies around the time of birth can have long-term impacts on individuals' economic productivity. Using unique data sets on historical weather and earnings, place and date of birth of all 1.5 million formal employees in Ecuador, we find that individuals who have experienced in-utero temperatures that are 1 °C above average are less educated and earn about 0.7% less as adults. Results are robust to alternative specifications and falsification tests and suggest that warming may have already caused adverse long-term economic impacts.  相似文献   
158.
Economists advocate for using the price mechanism to manage water scarcity, but complex nonlinear rate structures prevalent in markets for municipal water obscure price signals. We conduct a randomized field experiment that jointly elicits knowledge about the cost of water and examines the impact of improved information on demand by linking a survey to water billing records. Half of our sample of 30,000 single family homeowners are randomly sent an invitation to a survey that asks questions about the water bill and the costs of water-use activities (e.g. the cost of taking a shower), and subsequently provides personalized accurate information. Results show that consumers have poor information about the marginal price of water and overestimate the costs of using water. Respondents are relatively better informed about their total bill and water consumption. In aggregate, respondents increase water use in response to the survey, potentially due to learning that water is cheaper than they previously thought. Increased consumption is concentrated among low users who are more likely to over-estimate the costs of using water.  相似文献   
159.
Vlado Vivoda   《Resources Policy》2011,36(1):49-59
The aim of this paper is to assess the conditions that influence foreign direct investment in the mineral industries of China and India. The paper first surveys literature on the determinants of foreign direct investment to identify key conditions, under which host countries attract mining FDI. It then builds an evaluative framework which allows for comparative analysis. The paper then comparatively evaluates the performance of foreign investment regimes that govern mineral industries in China and India. Its findings show that the overall conditions for foreign mining investment in China and India are not favourable and that substantial policy, regulatory and other changes in both countries need to be made if more investment is to flow.  相似文献   
160.
Modelling ecological or environmental problems has potential to provide understanding of the causes of such problems and to indicate how to better manage them. Özesmi and Özesmi (2004) showed that cognitive or causal mapping can be used to develop maps of socio-ecological systems but these maps were based on stakeholders concerned with one ecosystem. This article shows how maps from a number of different dairy farmers in different locations, but each considering his or her own farm, can be used in meta analysis to make maps that represent how farmers think their farm ecosystem works. It also shows that the combination of causal mapping with the additional technique of Q method provides a useful solution to the practical problem of selecting from a sufficiently broad range of factors with potential to use in a map. Causal mapping in single or multiple locations contributes to the goal of using peoples’ knowledge of ecosystems to improve our understanding of socio-ecological systems.  相似文献   
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