Abstract: Described herein are examples of barbell weights which include a first surface having a circular shape defined by a diameter and a circumference. The weights include a second surface having the circular shape and positioned approximately parallel to the first surface. The weights include an exterior circumference edge extending between the first surface and the second surface around the circumference. The exterior circumference edge defines a width between the first surface and the second surface. The weights include a central axis aperture having an interior circumference edge extending from the first surface to the second surface. The weights include one or more grip apertures having an interior grip aperture edge extending from the first surface to the second surface.

Abstract: An indirect-fired gas turbine power plant comprises a compressor; a turbine mechanically coupled to the compressor; a furnace; a heat exchanger inside the furnace and fluidly coupled at an inlet end to the compressor and at an outlet end to the turbine; and means for forming a gas barrier around a portion of the heat exchanger to impede combustion products from contacting the heat exchanger. Such means can be a plurality of gas discharge manifolds located around a portion of the heat exchanger. The manifolds can be coupled to heated working gas exhausted by the turbine.

Abstract: A system for testing visual fields comprising a display for presenting a visual stimulus and an eye tracker for tracking movement of at least one of a patient's eyes to determine its position in three dimensions without requiring the patient to wear any tracking equipment. A computer controls the position of the stimulus on the display and causes it to move by an amount that is a function of the tracked three-dimensional position of the patient's eye and a visual field position that is to be tested. Changes to the position of the stimulus and any corresponding tracked eye movement are used to assess the patient's visual field.

Abstract: A system for testing visual fields comprising a display for presenting a visual stimulus and an eye tracker for tracking movement of at least one of a patient's eyes to determine its position in three dimensions without requiring the patient to wear any tracking equipment. A computer controls the position of the stimulus on the display and causes it to move by an amount that is a function of the tracked three-dimensional position of the patient's eye and a visual field position that is to be tested. Changes to the position of the stimulus and any corresponding tracked eye movement are used to assess the patient's visual field.

Abstract: An indirect-fired gas turbine power plant comprises a compressor; a turbine mechanically coupled to the compressor; a furnace; a heat exchanger inside the furnace and fluidly coupled at an inlet end to the compressor and at an outlet end to the turbine; and means for forming a gas barrier around a portion of the heat exchanger to impede combustion products from contacting the heat exchanger. Such means can be a plurality of gas discharge manifolds located around a portion of the heat exchanger. The manifolds can be coupled to heated working gas exhausted by the turbine.