BACKGROUND Dynamic gas compression during forced expiration has an influence on conventional flow-volume spirometry results. The extent of gas compression in different pulmonary disorders remains obscure. Utilizing a flow plethysmograph we determined the difference between thoracic and mouth flows during forced expiration as an indication of thoracic gas compression in subjects with different p...

The compression process in a piston cylinder device in a Compressed Air Energy Storage (CAES) system is studied computationally. Twelve different cases featuring four different compression space length-to-radius aspect ratios and three different Reynolds numbers are studied computationally using the commercial CFD code ANSYS FLUENT. The solutions show that for compression with a constant veloci...

Abstract This study develops a new phenomenological constitutive model to capture the unique evolving cyclic elastoplastic behaviours of hexagonal close-packed (HCP) sheet metals. is developed by adopting concepts multiple-yield surface approaches. Four deformation modes, including Monotonic Compression (MC), Tension (MT), Reverse (RC), and (RT), are considered represent hardening evolution mat...

conclusions after kyphoplasty, her pain was immediately resolved, vertebral body height was restored to normal, and pain score was reduced from 8 to 1. she was discharged with a normal neurological examination and good general condition, and returned to her normal life. in this case, balloon kyphoplasty resulted in the restoration of the vertebral body height, decrease in pain, and returning to...

We propose a compact approximation scheme for 3D curves. Consider a polygonal curve P, whose n vertices have been generated through adaptive (and nearly minimal) sampling, so that P approximates some original 3D curve, O, within tolerance 0. We present a practical and efficient algorithm for computing a continuous 3D curve C that approximates P within tolerance 1 and is composed of a chain of m...

PURPOSE To assess the consequences of lossy compression on the diagnostic accuracy of CT colonography for detecting colonic polyps. MATERIALS AND METHODS Helical CT images of cleansed colonic segments were evaluated. Source images were compressed to 1:1, 10:1, and 20:1 ratios with lossy wavelet compression. Two independent readers blinded to corresponding colonoscopic results analyzed 144 ran...

The authors apply a lossy compression algorithm to medical images, and quantify the quality of the images by the diagnostic performance of radiologists, as well as by traditional signal-to-noise ratios and subjective ratings. The authors' study is unlike previous studies of the effects of lossy compression in that they consider nonbinary detection tasks, simulate actual diagnostic practice inst...

The focus of this paper is to study the flow crossover between two adjacent flow channels in a proton exchange membrane (PEM) fuel cell with serpentine flow field design in bipolar plates. The effect of gas diffusion layer (GDL) deformation on the flow crossover due to the compression in a fuel cell assembly process is particularly investigated. A three-dimensional structural mechanics model is...

In order to quantify the effects of external compression on the muscular strength, fatigue, and activity through electromyography (EMG) and mechanomyography (MMG) during isokinetic muscle actions. 66.4 N and 85.8 N tension-length curves (used as moderate and high compression, respectively) were obtained with standard weights through a force transducer. All subjects (n = 12) performed 5 seconds ...