Oxygen cylinders are heavy and present a number of hazards, and liquid oxygen is too heavy and cumbersome to be used in far forward environments. Portable oxygen concentrators (POCs) and chemical oxygen generators (COGs) have been proposed as a solution. We evaluated 3 commercially available POCs and 3 COGs in a laboratory setting. Altitude testing was done at sea level and 8,000, 16,000, and 2...

The amounts of oxygen prescribed by general practitioners in each of 90 family practitioner committee areas of England in 1977-9 were compared using data supplied by the Prescription Pricing Authority and were matched with published mortality statistics for these areas. The annual number of 1360-litre cylinders supplied per thousand population ranged among family practitioner committees from 3....

The term ‘‘non-delivery LTOT’’ is used to describe installations of newer home oxygen therapy systems where oxygen concentrator technology is used to provide both stationary and ambulatory oxygen.1 The use of non-delivery LTOT equipment obviates the need for oxygen supply companies to make repeat (and costly) home deliveries to replenish depleted gaseous or liquid oxygen contents, the majority ...

BACKGROUND Lightweight portable oxygen systems are commonly preferred by patients over compressed-oxygen systems that use E-size cylinders. However, cost is often perceived as a barrier to the prescription of lightweight portable oxygen systems. OBJECTIVE To compare the overall health-care costs of patients with COPD who used lightweight portable oxygen systems to those who used E-cylinder sy...

Electromagnetic (EM) wave scattering by many parallel infinite cylinders is studied asymptotically as a → 0, where a is the radius of the cylinders. It is assumed that the centers of the cylinders x̂m are distributed so that N (∆) = ln( 1 a ) ∫ ∆ N(x)dx[1 + o(1)], where N (∆) is the number of points x̂m = (xm1, xm2) in an arbitrary open subset of the plane xOy, the axes of cylinders are parallel ...

This paper studies constructing advanced effective materials using arrays of circular radially-anisotropic (RA) cylinders. Homogenization of such cylinders is considered in an electrodynamic case based on Mie scattering theory. The homogenization procedure consists of two steps. First, we present an effectively isotropic model for individual cylinders, and second, we discuss the modeling of a l...

In Papua New Guinea (PNG), the most common cause of death among children under 5 years of age is pneumonia. Children with severe pneumonia need antibiotics and oxygen but oxygen shortages are common owing to the cost and complex logistics of transporting it in cylinders. Detection of hypoxaemia using clinical signs can be difficult, especially in highly pigmented children in whom cyanosis is di...

Measuring the rate of consumption of oxygen ( ) during swimming reveals the energetics of fish locomotion. We show that rainbow trout have substantially different oxygen requirements for station holding depending on which hydrodynamic microhabitats they choose to occupy around a cylinder. We used intermittent flow respirometry to show that an energetics hierarchy, whereby certain behaviors are ...