The effect of the price of gold on its production: a time-series analysis

Production of gold in Australia has grown strongly in recent years. Australia is ranked the world's third largest gold producer, only South Africa and the US produce more than Australia. Most of the Australian gold production comes from one of its states, Western Australia. In this paper, we use recent developments in econometric time series analysis to present an analysis of gold production and prices during the period 1948–1994. The results show that if the price of gold (relative to costs) increases by 10% and the price (in levels) remain the same for the next 5 years, then in the first year gold production will rise by 0.3%; in the second year by 2.2%; in the third year by 7.4%; in the fourth year by 8.9% and in the fifth year by 10.7%.     

Developing Peak Discharges for Future Flood Risk Studies Using IPCC's CMIP5 Climate Model Results and USGS WREG Program

Extreme climate events, floods, and drought, cause huge impact on daily lives. In order to produce society resilient to extreme events, it is necessary to assess the impact of frequent and high intensity storm events on design parameters. This article describes a methodology to develop future peak “design discharges” throughout the United States that can be used as a guidance to map future floodplains. In order to develop a lower and upper limit for anticipated peak flow discharges, two future growth scenarios — Representative Concentration Pathways (RCPs)‐RCP 2.6 and 8.5 were identified as the weak and strong climate scenario respectively based on the output from the global climate models. The Generalized Least Square technique in United States Geological Survey's Weighted Multiple Regression (WREG) program was used to develop regression equations that relate peak discharges to basin and climate parameters of the contributing watershed. The design discharges reflect the most recent climate model results. Number of frost days, heavy rainfall days, high temperature days, and snow depth were found to be the common extreme climate parameters influencing the regression equations. This methodology can be extended to other flood frequency events if rainfall data is available. The future discharges can be utilized in hydraulics models to estimate floodplains that can assist in resilient infrastructure planning and outline climate change adaptation strategies.     

A Framework to Develop Nationwide Flooding Extents Using Climate Models and Assess Forecast Potential for Flood Resilience

The methods used to simulate flood inundation extents can be significantly improved by high‐resolution spatial data captured over a large area. This paper presents a hydraulic analysis methodology and framework to estimate national‐level floodplain changes likely to be generated by climate change. The hydraulic analysis was performed using existing published Federal Emergency Management Agency 100‐year floodplains and estimated 100‐ and 10‐year return period peak flow discharges. The discharges were estimated using climate variables from global climate models for two future growth scenarios: Representative Concentration Pathways 2.6 and 8.5. River channel dimensions were developed based on existing regional United States Geological Survey publications relating bankfull discharges with channel characteristics. Mathematic relationships for channel bankfull topwidth, depth, and side slope to contributing drainage area measured at model cross sections were developed. The proposed framework can be utilized at a national level to identify critical areas for flood risk assessment. Existing hydraulic models at these “hot spots” could be repurposed for near–real‐time flood forecasting operations. Revitalizing these models for use in simulating flood scenarios in near–real time through the use of meteorological forecasts could provide useful information for first responders of flood emergencies.     

Electrochemical determination of methyl parathion using a modified electrode

Electrochemical studies of pesticides using various electrode systems attain prominence in recent years because of their application in trace determinations. Cyclic voltammetric studies of methyl parathion on a glassy carbon electrode at various pH in 50% aqueous ethanol medium were carried out. Influence of pH led to the selection of pH 1.0 as the best pH for the electroanalysis of methyl parathion. The number of electrons transferred was determined using controlled potential coulometry. On the basis of the results a probable reduction mechanism was proposed. Cyclic voltammetric studies of methyl parathion using polypyrrole deposited and sodium montmorillonite clay modified electrodes in the presence of cetyl trimethyl ammonium bromide were carried out. The clay-modified electrode and the reduction peak around ?0.2?V were selected for stripping analysis owing to their maximum current response. The experimental parameters were optimized using the differential pulse stripping mode. A calibration plot was made. The determination limit and standard deviations were arrived. The applicability of the method was also verified in a sample soil analysis.