Derivative mine valuation: strategic investment decisions in competitive markets

Successful management in competitive markets requires evaluation methods that respond to global market dynamics and provide investors with relevant information to make strategic investment decisions. These strategic decisions include decisions on investment timing, feasibility study and risk management and mine operating options. Conventional methods do not have the built-in capabilities to help investors handle these strategic issues. Advances in modern finance have had profound impacts on financial markets for options, futures and collaterized securities and offer appropriate tools in solving these problems. In this paper, the authors have extended the Brennan and Schwartz mineral resource model to develop the derivative mine valuation method based on the dynamic arbitrage theory. A copper mining venture has been evaluated using the derivative mine valuation and conventional methods. The results show that the derivative mine valuation method allows investors to maximize the venture's market value by exercising these strategic options.     

Ambient air concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans in Ohio: Sources and health risk assessment

PCDD and PCDF were measured in air samples collected in Ohio in 1987. No 2,3,7,8-TCDD was detected in any of the samples with a detection limits of less than 240 fg/m³. Using a chemical mass balance model applied to PCDD/PCDF congener group profiles, major potential sources of these compounds to the atmosphere in Ohio were determined to be municipal solid waste combustion, and sewage sludge combustion. Cancer risk calculations for inhalation of PCDD/PCDF in ambient air in Ohio are approximately 10–6. Given the current knowledge of the health effects of exposure to PCDD/PCDF in air, there is no appreciable risk to public health for the levels of these compounds found in ambient air in Ohio.     

Government policy influences on rangeland conditions in the United States: A case example

Since the early 1970s the Bureau of Land Management (BLM) and the Forest Service have emphasized the monitoring approach in managing their rangelands. After a 5-year period of intensive monitoring, stocking rate and other management actions are typically adjusted, depending on whether a definite downward or upward trend in range condition is observed. Examining the Afton Allotment on BLM land in southcentral New Mexico, we demonstrate serious flaws in the monitoring approach and other BLM grazing policies. Monitoring reflects past management but does not consider the future. Perverse incentives for permittees to maximize permit value rather than sustain the forage base still remain in place. The Range Reform '94 proposals by the U.S. Department of the Interior do not address these incentives and other flaws in public land policy. We would reform federal grazing land policy by coupling grazing fees to grazing intensity. Ranchers choosing conservative sustainable grazing intensities would pay low fees, whereas those choosing heavy grazing intensities would be charged higher rates. We would also implement other reforms: making livestock grazing permits transferable to other uses, discontinuing subsidies, eliminating restrictions on nonuse, offering incentives for public land investment, and establishing a biodiversity fund.This paper was supported by the New Mexico Agricultural Experiment Station, Las Cruces and was part of project 1-5-27417.     

Modelling of pharmaceutical residues in Australian sewage by quantities of use and fugacity calculations

A conceptual model is presented for determining which currently prescribed pharmaceutical compounds are most likely to be found in sewage, and for estimating their concentrations, both in raw sewage and after successive stages of secondary sewage treatment. A ranking of the "top-50" pharmaceutical compounds (by total mass dispensed) in Australia over the 1998 calendar year was prepared. Information on the excretion ratios and some metabolites of the pharmaceuticals enabled prediction of the overall rates of excretion into Australian sewage. Mass-balance and fugacity modelling, applied to sewage generation and to a sewage treatment plant, allowed calculation of predicted concentrations of the compounds in raw, primary and secondary treated sewage effluents. Twenty nine of the modelled pharmaceutical residuals were predicted to be present in raw sewage influent at concentrations of 1 microgl(-1) or greater. Twenty of the compounds were predicted to remain in secondary effluent at concentrations of 1 microgl(-1) or greater.     

FIELD SCALE MULTIOBJECTIVE DECISION MAKING: A CASE STUDY FROM WESTERN IOWA1

ABSTRACT: Water quality issues in agriculture are growing in importance. A common theme is the provision of better information to decision makers. This study reports the trial of a prototype decision support system by the U.S. Department of Agriculture Natural Resources Conservation Service and the Agricultural Research Service in the NRCS Harrison County Field Office in 1998. Observed data collected at the Deep Loess Research Station (DLRS) near Treynor, Iowa, were extrapolated using a modified GLEAMS field scale simulation model that included a nitrogen leaching component and a crop growth component. An accounting tool was used to convert crop yield estimates into crop budgets. A model interface was built to specify the climate, soil, and topography of the field, as well as the management scenarios for the alternative management systems. For the Deep Loess Hills area of Harrison County, a total of six soil and slope groups, with 66 total combinations of management practices forming management systems, were defined and simulated based on previously calibrated data from DLRS. A multi‐objective decision support system, the Water Quality Decision Support System, or WQDSS, was used to examine the tradeoffs in a comprehensive set of variables affected by alternative management systems with farmers in Harrison County. The study concluded that a multiobjective decision support system should be developed to support conservation planning by the NRCS. Currently, a larger scale effort to improve water quality decision making is underway.     

AN INTERDISCIPLINARY APPROACH TO VALUING WATER FROM BRUSH CONTROL1

ABSTRACT: An analytic methodology utilizing models from three disciplines is developed to assess the viability of brush control for water yield in the Frio River basin, Texas. Ecological, hydrologic, and economic models are used to portray changes in forage production and water supply resulting from brush control, and to value supplemental water produced through brush control. Site‐specific biophysical characteristics are used to simulate water yields from brush control across the watershed. Economic benefits from increased animal production for ranchers undertaking brush control are assessed. Benefits to Corpus Christi residential water consumers from ranchers' brush control activities are evaluated using the change in consumer surplus resulting from supplemental water produced through brush control. Results indicate an increase in water yield with brush control on 35 percent of the land area in the basin. However, the cost of brush control is more than the increase in returns it fosters on most range sites. Consumer surplus change for Corpus Christi residents over 25 years is zero under baseline conditions, implying subsidies for brush control in the Frio basin are not worthwhile at this time.     

液相飞行时间质谱(LC/MSD TOF)和液相色谱/离子阱质谱(LC/MSD Trap)测定色拉蔬菜中的氯烟碱类杀虫剂

本工作考察了液相色谱／飞行时间质谱检测器(LC／MSDTOF)和液相／离子阱质谱检测器(LC／MSD Trap)联用技术分析一些氯烟碱类杀虫剂的可行性．杀虫剂包括：啶虫咪(acetamiprid)，吡虫啉(imidacloprid)和噻虫啉(thiacloprid)．色拉蔬菜有四种：番茄、辣椒、莴苣和黄瓜．本文介绍的内容包括三种氯烟碱类杀虫剂的LC／MSDTOF和LC／MSD Trap质谱，TOF获得的实验分子式和四种蔬菜基质中氯烟碱类杀虫剂的MS／MS碎片离子．同时也将详细介绍样品制备程序以及色拉蔬菜中杀虫剂的回收、最低检测限(MDL)的质谱质量、线性，使用TOF和Trap对纯溶剂和四种蔬菜提取物中杀虫剂的定量分析．给出了来自市场的实际色拉蔬菜样品中杀虫剂的分析结果．     

PARAMETER DETERMINATION FOR THE MUSKINGUM-CUNGE FLOOD ROUTING METHOD1

ABSTRACT: The proportionality coefficient, K, and the weighing parameter, X, required for the Muskingum-Cunge Flood Routing Method are dependent on the hydraulic characteristics of the channel and the dynamic characteristic of the flood wave. This work focuses on the determination of the Muskingum-Cunge Flood Routing Method parameters for streams where measured hydrographs are not available (i.e., ungaged streams) with floods that stay within the channel banks. In the present work, a gaged creek was used and a dynamic wave was routed to test the reliability of the parameters determined through the Schaefer and Stevens technique (Schaefer and Stevens, 1978). The predicted outflow hydrographs are compared to the hydrographs obtained for the same stream determined with the Muskingum Routing option of the HEC-1 program. Cypress Creek in Harris County, Texas, was the model for this work; and the corresponding data were extracted from the Grant Road and Westfield, Texas, USGS gaging stations.     

Catalase activity of activated sludge

Catalase activity of mixed liquor suspended solids of aeration tank of activated sludge plants in Milwaukee, WI, was measured in sonicated samples. Catalase activity varied in the samples of mixed liquor suspended solids collected from the head and end of the aeration tanks; in return activated sludge; and in waste activated sludge. Catalase activity decreased in mixed liquor suspended solids, on prolonged aeration (8 days), in the absence of added sewage. Volatile suspended solids and catalase activity seemed to bear a relationship.