The wick catheter technique for measurement of intramuscular pressure. A new research and clinical tool

The wick catheter technique was developed in 1968 for measurement of subcutaneous pressure and has been modified for easy intramuscular insertion and continuous recording of interstitial fluid pressure in animals and humans. Studies in dogs of the anterolateral compartment of the leg in simulation of the compartment syndrome showed the technique to be accurate and reproducible. The wick catheter technique is capable of important clinical applications in the diagnosis and treatment of acute and chronic compartment syndromes.     

Elastoplastic and geometrically nonlinear thin shell analysis by the semiloof element

This paper extends the use of the Semiloof shell element to geometrically and materially nonlinear situations. For the geometrically nonlinear analysis a moving coordinate process is used. Local coordinate systems are considered, one at each integrating point, which move with the structure and allow deformation and rotation within the element to be taken into account. For elasto-plastic analysis the initial stress method is used and the yield conditions are expressed in terms of nondimensional stress resultants. The element formulation is briefly considered and in particular the definition of the global and local displacements and their first and second derivatives in the non-constrained and constrained form of the element are discussed. Numerical results are presented and comparisons made with other sources where available.     

Analysis of viscoplastic effects in pressure vessels by the finite element method

In this paper it is shown how the finite element technique can be employed in the solution of elastic-viscoplastic problems. By attaining steady-state conditions the process offers an alternative method of solution for elasto-plastic situations. The solution algorithm employed is relatively simple and possesses many advantages over the conventional computational procedures utilized in elasto-plastic material analysis. Strain-softening materials present no difficulty and it is indicated how viscoelastic-plastic situations could also be analyzed. Several examples of interest to pressure vessel technology are presented and in particular the pressure loading of a spherical pressure vessel containing a flush nozzle junction is considered.     

Preparation and electro-optic properties of 1-formyl 2(4-nitrophenyl) hydrazine

The chemical preparation and crystal growth of 1-formyl 2(4-nitrophenyl) hydrazine are described. Its refractive indices, optical absorption coefficients and electro-optic half-wave voltages at zero and 1 MHz frequencies are reported. The method used for the determination of the half-wave voltage at 1 MHz was extremely sensitive, and could provide a useful test for optical non-linearity in small crystals.     

Age effects and revised scoring of the Canter BIP for identifying children with cerebral dysfunction.

Performed an item analysis of the Canter Background Interference Procedure (BIP), a test for brain damage, to select items and weight them to maximize the efficiency of discriminating children with cerebral dysfunction from those with no dysfunction. Attempts to improve discrimination of these 2 groups of Ss on the BIP were successful only after age differences were considered, especially between 10- and 11-yr-old children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reviews

A VISUAL APPROACH TO PARK DESIGN by A. J. Rutledge, John Wiley, 1985. 180pp.

FIFTY YEARS OF LANDSCAPE DESIGN: 1934-84 Edited by Sheila Harvey and Stephen Rettig, Landscape Press, 1985.

DES PAYSAGES, POUR QUI? POURQUOI? COMMENT? by Georges Neuray, Les Presses Agronomiques de Gembloux, Belgium, 1982, 589 pp. 1640 Belgian Francs.

THE PAST IS A FOREIGN COUNTRY by Professor David Lowenthal, Cambridge University Press, 1985, 490 pp, £27.50 (H/B), £9.95 (P/B).

INTERPRETING THE LANDSCAPE: LANDSCAPE ARCHAEOLOGY IN LOCAL STUDIES by Michael Aston. B. T. Batsford, London 1985. Price £9.95 (P/B).

AGRICULTURAL LANDSCAPES: A SECOND LOOK, by R. Westmacott and T. Worthington, Countryside Commission (CCP 168, 1984) £7.00

AGRICULTURAL LANDSCAPES: AN APPROACH TO THE IMPROVEMENT, by P. Hamilton and J. Woolcock, Countryside Commission (CCP 169, 1984) £8.00

AGRICULTURAL LANDSCAPES: DEMONSTRATION FARMS, by R. Cobham et al, Countryside Commission (CCP 170, 1984) £13.00

REVIEWS OF UNITED KINGDOM STATISTICAL SOURCES, VOLUME XVII, Weather by B. W. Atkinson and Water by E. C. Penning-Rowsell and D. J. Porter. Published for the Royal Statistical Society and Economic and Social Research Council by Pergamon Press, 1985, 266 pp.

THE COUNTRYSIDE HANDBOOK by Alan Rogers, John Blunden and Nigel Curry, Open University/Croom Helm, 1985, 98 pp, £5.95.

THE CHANGING COUNTRYSIDE — edited by John Blunden and Nigel Curry. Open University/Croom Helm, 1985, 270 pp, £11.95.     

Structural instability and natural vibration analysis of thin arbitrary shells by use of the Semiloof element

At present the Semiloof element is probably one of the most efficient available for the solution of thin shells of arbitrary geometry. Experience in static situations indicates that accurate results can be obtained for non-trivial geometric and loading configurations with relatively coarse meshes. Variable thickness shells or discontinuous thicknesses can be accommodated and no difficulties are encountered in modelling sharp corners or multiple junctions in structures. The element is basically non-conforming but some measure of C¹ continuity is provided by the introduction of normal rotation variables at Loof nodes on the element boundary. This paper examines the element behaviour when applied to elastic instability and vibration situations. An eigenvalue solution scheme based on Sturm sequences is presented which does not require the usual elimination of a percentage of the total nodal variables by static condensation. Finally the method is assessed by the solution of several numerical examples.     

Surface tension of polytrifluoropropylmethylsiloxane

Surface tension studies of the most common fluorosilicone, poly(3,3,3-trifluoropropylmethylsiloxane) (PTFPMS), give unexpected results. Compared to polydimethylsiloxane (PDMS), the liquid surface tension is higher, the critical surface tension of wetting similar, and the solid surface tension, determined by water and methylene iodide contact angles and the method of Owens and Wendt, considerably lower. As the outermost surface of the lowest energy materials are comprised of close-packed perfluoromethyl groups and as a flexible polymer backbone should aid in the adoption of the lowest surface energy configuration, fluorosilicones could in principle be the lowest surface energy polymers. In practice, other groups such as the ethylene link between the perfluoromethyl group and the siloxane backbone in PTFPMS are required to produce a stable material. This introduces factors such as bulkiness of side chains, unresolved fluorocarbon/hydrocarbon dipoles, and fluorine/silicon coordination effects. The results are discussed in these terms and compared with PDMS and two fluoropolymers, polytetrafluoroethylene (PTFE) and polychlorotrifluoroethylene (PCTFE). PTFE shows similar trends to PTFPMS whereas PCTFE behaves rather like PDMS.