\u3cem\u3eDieppe Revisited: A Documentary Investigation\u3c/em\u3e by John P. Campbell [Review]

Review of John P. Campbell, Dieppe Revisited: A Documentary Investigation. London: Frank Cass, 1993

3D Simulation of Partial Discharge in High Voltage Power Networks

Open accessPartial discharge (PD) events arise inside power cables due to defects of cable’s insulation material, characterized by a lower electrical breakdown strength than the surrounding dielectric material. These electrical discharges cause signals to propagate along the cable, manifesting as noise phenomena. More significantly, they contribute to insulation degradation and can produce a disruptive effect with a consequent interruption of power network operation. PD events are, therefore, one of the best ‘early warning’ indicators of insulation degradation and, for this reason, the modeling and studying of such phenomena, together with the development of on-line PDs location methods, are important topics for network integrity assessment, and to define methods to improve the power networks’ Electricity Security. This paper presents a 3D model of PD events inside a void in epoxy-resin insulation cables for High Voltage (HV) power networks. The 3D model has been developed using the High Frequency (HF) Solver of CST Studio Suite® software. PD events of a few µs duration have been modelled and analyzed. The PD behavior has been investigated using varying electrical stress. A first study of the PD signal propagation in a power network is described

Managing Water Shortages in the Western Electricity Grids

British Columbia’s electricity grid is comprised primarily of hydroelectric generating assets. The ability to store water in reservoirs is a significant advantage for the province allowing it to import from Alberta when prices are favourable. Alberta, has a heavily fossil-fuel based electricity portfolio, but has seen substantial growth in its wind energy capacity. However this variable energy technology impacts the province’s grid operations. Wind energy is both variable and uncertainty. However, wind energy in Alberta can be stored via BC’s reservoir systems. In this paper, we examine the extent that drought impacts the both overall operating costs as well as the cost of reducing CO2 emissions. We model the Alberta and BC interconnected grids varying both the impact of the drought and the transmission capacity between the provinces. We determine that storing wind energy leads to an overall cost reduction and that emission costs are between $20 and$60 per tonne of CO2.Wind power, carbon costs, electrical grids, mathematical programming

A comparison of the estimated consumption functions for meat from two different samples

The objectives of this study were (1) to determine if a 1967 survey on meat consumption in Knoxville, Tennessee, conducted by Williams was taken from the same population as a 1965 survey on food consumption in urban areas of the South conducted by the Consumer and Food Research Division of the Agricultural Research Service, and (2) to compare the estimated consumption functions for meat for these two data sets. The information presented in the two data sets was made as alike as possible. The two data sets were combined to form a third data set. These three data sets were analyzed using the same models. Ordinary least squares regression was utilized in the analysis. Six models were fitted using both total quantity and total expenditures as the dependent variables. Models I and II assumed the dependent variables to be functions of annual household disposable income and 17 other socio-economic factors while Models III, IV, V, and VI assumed total quantity and total expenditures were functions of income only. Income for Models I and III were coded from 1 to 14 representing 14 different income groups. For Models II and IV, income was treated as 14 different 0,1 dummy variables, a dummy variable representing each income group. These income groups were as follows: under $1,000;$1,000-1,999, $2,000-2,999;$3,000-3,999, $4,000-4,999;$5,000-5,999; $6,000-6,999;$7,000-7,999, $8,000-8,999,$9,000-9,999; $10,000-11,999;$12,000-14,999; $15,000-24,999; and$25,000 or over. Model V measured income in groups of $0-2,999;$3,000-5,999; $6,000-8,999;$9,000-11,999; and $12,000 or over. Model VI measured income in groups of$0-1,999; $2,000-3,999;$4,000-5,999; $6,000-7,999;$8,000-9,999; $10,000-14,999; and$15,000 or over. There existed a 0,1 dummy variable for each income group for Models V and VI. Varying results were obtained from the use of these six models. Different amounts of variation in total quantity and total expenditures were explained for the Knoxville Survey and the \u2765 Household Survey. These models also found different variables significant for the two data sets. The same sign did not always appear for a given variable for both data sets. However, a general dip in consumption in both data sets did occur. By using a form of the F test, it was concluded that the Knoxville Survey data and the \u2765 Household Survey data did not have the same relationship to meat consumption and expenditures for meat