Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valve assemblies (GLV). One failure mode occurs when the GLV check valve fails and product passes into the well annulus, potentially reaching the wellhead. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure conditions, and repair and ...

The two cases to be presented demonstrate ventilatory insufficiency of the restrictive type due ,in the first instance to primary neuromuscular dysfunction and in the second to chronic pleural disease with resulting calcification and restriction of the underlying parenchyma and diaphragm. Of particular interest was the development of congestive heart failure in both of these patients. These cas...

We describe a patient with frontometaphyseal dysplasia (FMD), restrictive chest bellows disease, hypercapnic respiratory failure, and cor pulmonale. Treatment with intermittent supplemental oxygen, nocturnal nasal volume ventilation, and posture modification was successful in partial resolution of chronic hypoventilation and excessive daytime somnolence.

We developed a laboratory method to obtain high precision CO2 mixing ratios in air samples contained in 100 ml glass flasks, which involves extracting air from the flask into a pre-evacuated manifold containing a variable-volume metal bellows. Compressed air from the bellows is then routed to a non-dispersive infrared gas analyzer (IRGA). Tests indicate that this configuration has an overall ac...

Aleksandrov and Pogorelov used bending fields (the velocity fields of continuous isometric deformations) to show infinitesimal rigidity of some classes of surfaces ([2] and [12]). Bending fields (and the rigidity matrix) were also successfully employed in the study of infinitesimal rigidity of polyhedra and tensegrity frameworks (see [7]). We will use these tools to re-derive a previously known...

Abstract Origami bellows are formed by folding flat sheets into closed cylindrical structures along predefined creases. As the unfold, volume of origami structure will change significantly, offering potential for use as inflatable deployable structures. This paper presents a geometric study multi-stable Miura-ori and Kresling bellows, focusing on their application space habitats. Such habitats ...