Journal of Energy in Southern Africa • Vol 19 No 3 • August 2008 Abstract Worldwide attempts are being made to increase the use of our renewable energy sources as well as to use our current fossil fuel energy sources more efficiently. Waste heat recovery forms a substantial part of the latter and is the focus of this project. Stirling technology finds application in both the renewable energy se...

Enteropathogenic Escherichia coli (EPEC) causes severe, watery diarrhea in children. We investigated ATP release during EPEC-mediated killing of human cell lines and whether released adenine nucleotides function as secretory mediators. EPEC triggered a release of ATP from all human cell lines tested: HeLa, COS-7, and T84 (colon cells) as measured using a luciferase kit. Accumulation of ATP in t...

The amine regenerator of acid removal unit in South Pars Gas Complex, Assalouyeh, Iran was modeled. This model was fitted to assess the large scale columns and allow application of solar thermal energy for production of low pressure steam. Heat transfer fluids including Therminol oil, sulfur, or salt melt could be applied to yield thermal energy from a solar collector and to store and transfer ...

A thermodynamic model of an open combined regenerative Brayton and inverse Brayton cycles with regeneration before the inverse cycle is established in this paper by using thermodynamic optimization theory. The flow processes of the working fluid with the pressure drops and the size constraint of the real power plant are modeled. There are 13 flow resistances encountered by the working fluid str...

Experiments were performed to study the effects of introducing vapor into a dewar where a coaxial pulse tube refrigerator was used as a liquefier in the neck of the dewar. We were concerned about how the introduction of vapor might impact the refrigeration load as the vapor barrier in the neck of the dewar is disturbed. Three experiments were performed where the input power to the cooler was he...

The Magneto Caloric Effect is an intrinsic property of a magnetic solid. It is the response of this solid to the application or removal of magnetic fields. When magnetic material (Regenerator) is subjected to a magnetic field the magnetic moments are aligned and the magnetic entropy is lower. And the sample heats up when the field is removed the magnetic entropy is increased and the temperature...

In this study, the authors discuss the mitigation of negative-exponential fading in optical wireless communication systems. The mitigation technique involves the utilisation of a semiconductor optical amplifier (SOA) that, depending on the link arrangement, acts either as regenerator or pre-amplifier. As a regenerator, the SOA gain saturates during normal link operation and increases when the l...

The regenerator plays an extremely important role in the Stirling circulation. A grid can be used for inverse machines at room temperature due to its low flow resistance. This paper proposes a hexagonal theoretically explore heat transfer properties cycle and establishes approximate analytical model analyze effect mechanism of working frequency, thermal diffusivity wall thickness on oscillation...

Magnetic cooling has been researched as an alternative near room-temperature refrigeration technology for the past two decades. However, one of its greatest limitations is lack materials which can be properly shaped optimal thermal-hydraulic performance while maintaining a substantial magnetocaloric effect at moderate fields (i.e., between 1 and 2 T) remaining mechanically (and chemically) stab...