Kilojoules Of Energy Research Articles

Estimations of compatibility of supercapacitors for use as power sources for resistance welding guns

Supercapacitors offer potential for several kilojoules of energy to be proved in a small package with limited charge voltage (few volts). A preliminary examination of supercapacitors suggests that both the voltages used and retainable energies are well matched for resistance spot welding applications. Utilization of supercapacitors as resistance welding power supplies offers significant weight reduction over conventional (transformer and power supply) approaches, with subsequent economic advantages. In this work, some preliminary analyses have been done to assess the potential for using supercapacitors as resistance welding power supplies. This was done by integrating two separate analyses: one to assess the inductive response of specific weld gun designs and the second to define the current response of supercapacitors matched with that inductance. Results demonstrated potential for achieving desired currents and pulse widths with the proper selection of supercapacitor type and arrangement as well as secondary gun configuration. These analyses were further used to understand implications of system design on overall deliverable current capability. While the results described here only describe potential, some recommendations are made for next steps advancing supercapacitor-based resistance spot weld gun technology.

Psuing the Limits

This article focuses on DuPont’s goal to produce a low-cost, reliable, easy-to-maintain high-temperature superconductivity (HTS) magnetic separator that will meet the commercial needs of remote ore processing operations. DuPont’s superconductivity business is finishing the detailed design of a pilot separator for processing kaolin clay and titanium dioxide ore. The separator will incorporate the largest high-temperature superconductivity magnet, in terms of combined size, magnetic field, and stored energy, that has ever been built. The 0.8-m-dianleter magnet will deliver a 2.5 tesla magnetic field and store 800 kilojoules of energy. DuPont is addressing the strength issues with a mechanical support structure that reinforces and supports the windings and does double duty as part of the conduction cooling process.

Contrasting resource allocation patterns in Sedum lanceolatum Torr.: Biomass versus energy estimates.

Biomass determinations and microbomb calorimetry were used to assess resource allocation in Sedum lanceolatum Torr. between 2,257 and 3,726 m above sea level in the Front Range of the Rocky Mountains, Colorado, USA. In general, energy values did not differ within a tissue among sites, but did differ among tissue types. Flowers and leaves had the greatest energy content per gram ashfree dry weight. Total kilojoules per plant were homogeneous along the elevational gradient.Allocation patterns based on kilojoules of energy and grams of biomass were not highly correlated, with the exception of the percent investment in sexual tissues. Allocations to sexual tissues based on dry weight and energy were negatively correlated, revealing opposing trends of sexual investment with the increase in elevation. Due to the greater biomass investment in high energy leaves and flowers by populations of Sedum lanceolatum at higher elevations, allocation to sexual reproduction based on calorimetric analysis increased from 18.3 to 38.3% along the 1,469 m change in elevation. Although biomass can represent energy allocation in some taxa, for those species that change morphologically or physiologically along an environmental gradient, these two methods may not reveal similar trends.