bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased systemic availability of loperamide after oral administration of loperamide and loperamide oxide with cotrimoxazole
Authors: KAMALI F. , HUANG M. L. 
Published: October 2008

1 The effects of concurrent administration of cotrimoxazole on the plasma concentration‐time profiles of loperamide and its oxide were investigated in two separate studies in healthy male volunteers. Cotrimoxazole (960 mg, twice daily) was administered for 24 h before and 48 h after an oral dose of loperamide oxide (4 mg) or loperamide (4 mg).2 Coadministration of cotrimoxazole with loperamide oxide did not alter the tmax'Cmaxand AUC of loperamide oxide, whereas the Cmax(0.32 ± 0.14 ng ml‐1without cotrimoxazole; 0.45 ± 0.18 ng ml‐1with cotrimoxazole;P< 0.05) and AUC (8.13 ± 1.91 ng ml‐1h without cotrimoxazole; 12.50 ± 4.60 ng ml‐1h with cotrimoxazole;P< 0.005) of loperamide were significantly increased.3 Coadministration of cotrimoxazole with loperamide significantly increased the Cmax(0.74 ± 0.22 ng ml‐1without cotrimoxazole; 1.49 ± 0.81 ng ml‐1with cotrimoxazole;P< 0.01) and AUC (13.40 ± 3.80 ng ml‐1h without cotrimoxazole; 25.30 ± 11.10 ng ml‐1h with cotrimoxazole;P< 0.005) of loperamide, whilst its tmaxand t1/2, zwere not significantly altered.4 The increase in loperamide AUC, following coadministration of either loperamide oxide or loperamide with cotrimoxazole, may be due to reduced first pass metabolism of loperamide.
Caffeine as a metabolic probe: NAT2 phenotyping
Authors: NOTARIANNI LIDIA J. , DOBROCKY P. , GODLEWSKI G. , JONES R. W. , BENNETT P. N. 
Published: October 2008

1 Caffeine has been used to determine acetylator phenotype for some 15 years but the interpretation of metabolic ratios with this substance raises theoretical and methodological issues.2 N‐acetyltransferase type 2 (NAT2) status was assessed in 23 young healthy subjects using both caffeine overnight and spot urine samples, and sulphadimidine.3 Frequency distribution analysis of the metabolic ratios of NAT2, indicated two distinct groups for sulphadimidine, and for caffeine spot but not overnight samples. Spearman's rank correlation values were low indicating differences between the data sets for sulphadimidine and spot caffeine samples. Correlation between the two urine collection periods for caffeine was poor.4 The complex metabolism of caffeine may compromise its value as a probe for determining acetylator phenotype until the effects of important variables are better understood.
Crossover trials are only useful when there is a positive correlation between the response to different treatment modalities
Authors: CLEOPHAS T. J. M. 
Published: October 2008

1 Trials that do not allow us to reject the null hypothesis of no treatment effect may have had an inappropriate design. Trials are virtually never assessed for correlation between responses to different treatment modalities.2 The level of correlation between responses to different treatment modalities is a major determinant of the power of crossover trials.3 It is relevant to assess correlation levels between responses to the different treatment modalities a priori. With a negative correlation a crossover design is likely to lack power.4 In 1991 the British Journal of Clinical Pharmacology published eight crossover trials which would have been more efficient had they been performed with a parallel groups design.
A SELF‐ALIGNING DIAPHRAGM LOAD CELL
Authors: CHAN K. S. 
Published: October 2008

SummaryA description is given of the design and construction of a short, simple, self‐aligning load cell used in confined spaces. The cell, capable of very good accuracy, consists of a thick diaphragm and a self‐aligning anvil with two electrical strain gauges fixed on the underside of the diaphragm. The signal output against load characteristic is linear, and loads up to several tons can be measured.
Use of extensometers with spherically pointed pin ends for accurate determination of material qualities
Authors: BERGQVIST B. 
Published: October 2008

Highly accurate FFA 10 mm inductive extensometers with spherical tips are used for materials testing. The pin ends are ground conical and spherically pointed ends of 16tm radius are then honed. The specimen is indented with a slightly greater cone angle and with the same nose radius by a similar conical‐spherical taper shank. The extensometer is mounted in these indentations under a spring pressure that plasticises the spherical contact area and squeezes out unevennesses.The shear modulus of steel was evaluated from four values of Young's modulus and four of Poisson's ratio in tension and compression, determined with such extensometers in 16 different tests under dead weights calibrated by the official standards institute. The four shear modulus values obtained have root mean square errors within ±0.5%.
Linear strain–displacement interpretation of thin shells of revolution
Authors: DELPAK R. , PREECE B. W. 
Published: October 2008

The general strain–displacement equations of Novozhilov have been simplified for the particular case of a shell of revolution. The simplified equations. with one exception, agree with those obtained by Klein. Each of the expressions has been investigated in an effort to attach physical significance to every term.The equations have finally been transformed from a local co–ordinate system to a global system. This latter form is ideally suited to numerical procedures.
The acquisition and processing of torque–twist data in torsion testing with overstrain
Authors: SWIFT W. A. C. 
Published: October 2008

A description is given of tests carried out on torsion bars and tubes of spring steel subjected to various degrees of overstraining. The results of the tests on tubes involving loading into the plastic region, unloading and reverse–loading, again into the plastic region, were combined for a number of spring steels in order to produce Bauschinger Charts. To make them more convenient for use in the prediction of the residual stress distribution in overstrained bars, the charts were then subjected to a ‘standardising’ process by constructing lines at equal increments of strain.In order to obtain torque–twist data, an autographic recording rig operating over a known gauge length, was designed and manufactured. This rig could be converted to a trace reader so as to digitise the torque–twist data.
Correcting for the effects of temperature on strain gauges —‐use of computer–logger on Milford Haven Bridge project
Authors: CULLINGTON D. W. , HOAR M. C. P. 
Published: October 2008

The effects of temperature changes on strain gauge readings depend partly on the characteristics of the gauge and measuring equipment, and partly on the thermal properties of the structure being tested. The effect on the gauge can be numerically corrected, or compensated for by experimental techniques, and if required, the effect of temperature changes on the structure can be reduced by careful selection of the time of reading. Correction of Demec, vibrating wire and electrical resistance strain gauge outputs is discussed.Experience with a computer controlled data logger used to correct for thermal effects on a 1/4‐bridge electrical resistance strain gauge installation is described. The use of this system on the Milford Haven Bridge is estimated to have reduced potential temperature errors from between ±100 to 200 μstrain to about ±20 to 30 μstrain.
Transverse vibration of a cylindrical shell with torispherical head: model tests and stress analysis
Authors: BARRON R. , VILLAIMUEVA C. 
Published: October 2008

As an aid in the design of vessels or containers in a process undergoing dynamic loading, the dynamic characteristics of a cylindrical scale model vessel have been investigated by the method of resonance testing. The scale model is 1/10th scale of a vessel in a process, comprising a cylinder and torispherical head of steel.The dynamic characteristics of the scale model vessel and the normalised principal bending stresses are calculated and tabulated for a number of circumferential modes of vibration, for an empty vessel.Practical problems associated with the method of vibration testing are discussed and a practical example shown of the use of the method of dynamic similarity and the scale model results, as an aid in the design of a full scale vessel.
Determination of thermal stress in concrete pavements by means of measurement of in‐situ strains
Authors: HSIANG‐TE TU 
Published: October 2008

A new method of determining the thermal stress of concrete pavement in‐situ has been developed and applied to engineering practice with success. It consists of three parts:1. A system of theorems was established on the basis of mathematical modelisation that both temperature and thermal strain were sine functions of t, the time of observation, owing to the daily fluctuations of temperature and consequently the corresponding thermal strain. It was found that there exist a time phase and an angle of axes rotation between temperature and thermal strain.2. A bridge circuit with a strain block and specially designed equipment ‘free body’ was introduced. The strain transducer for every test point consists of one strain gauge in the strain block and one in the ‘free body’, the former is used as the active gauge in the bridge circuit and the latter as the dummy. A temperature probe of resistance type was inserted nearby each of the gauges. Arrangement of observations and procedure of the data treatment were stated.
The prediction and measurement of axial forces, bending moments and accelerations in an engine connecting rod
Authors: Tilbury R. J. 
Published: October 2008

The graphs, numbered 1–5 reproduced below, were omitted from the above paper. Any inconvenience to the readers is regretted.The author wishes also to acknowledge with grateful thanks the assistance given to him by, the Department of Mechanical Engineering, Lanchester College of Technology, Coventry, where the work was carried out.
Some proposals for the application of liquid crystals to photoelastic instrumentation
Authors: HEARN E. J. , GORMAN B. 
Published: October 2008

Liquid crystal displays (L.C.D.'s) are well known for their application to electronic watches, calculators, games and digital thermometers, the technology involved being derived from electro‐optic effects observed in liquid crystals since about 1968. This paper describes proposals for a totally different application of one particular class of liquid crystal, as an optical element in a photoelastic transmission or reflective polariscope.The proposals are currently under development* and considerable work remains before this particular application of liquid crystals is perfected. Early results are promising and if successful they could well produce a revolution in the design of optical equipment with particular attraction to automatic systems incorporating microcomputer control.
The use of vibrating wire strain gauges for long term measurements on buried gas mains
Authors: Osborne G. 
Published: October 2008

A trial agreement concerned with the effect of adjacent deep excavations on the risk of failure of buried cast iron gas and water mains was implemented by British Gas and National Water Council on 1 January 1983. To complement this agreement, field experiments are being carried out at selected sites throughout the UK. The British Gas Engineering Research Station (ERS) is working in cooperation with the Water Research Centre to install instrumentation to measure pipe strains, joint movement, ground temperature and ground movement.Field measurements impose environmental and operating conditions of much greater severity than those encountered in a laboratory. This note outlines the site techniques developed by ERS which allow reasonably quick and reliable installation of equipment capable of withstanding the adverse conditions typical of backfilled trenches. The principle of operation of the VW gauge, its method of fixing, the factors affecting its output and the interpretation of the readings themselves are described.
Photographic evaluation techniques in photoelasticity—Part 2
Authors: Meyer M. L. , Mehrotra L. 
Published: October 2008

In Part 1, boundaries between black and white on high contrast photographs (e.g. Fig. 10) and lines on Agfacontour photographs (e.g. Fig. 15) have both been called E‐lines. On any given photograph of isochromatics, each E‐line denotes a specific fractional fringe order N = Ni|δN|, with integer orders Nit and all E‐lines have the same fractional order modulus. |δN| (0 ≤ |δN| ≤ 1/2). Exposure or processing changes lead to photographs with different E‐lines and |δN| values.Part 2 treats evaluation and calibration of isochromatic E‐lines, gives examples and notes on illustrations of Part 1, discusses applications to isoclinics, and summarises some main features.
The dispersion of birefringence in photoelastic materials
Authors: Haake S. J. , Patterson E. A. 
Published: October 2008

AbstractA spectral analyser was used to determine the variation with wavelength known as the dispersion of birefringence of the fringe constant f and the stress optic coefficient C for photoelastic materials. A disc was loaded diametrically and was subjected to the stress freezing thermal cycle. The intensity was measured along the diameter perpendicular to the load for wavelengths between 450 and 850 nm at 5 nm intervals. Using the theoretical solution to the stresses it was possible to calculate the stress optic coefficient for all wavelengths employed. A similar technique was used for an identical disc that was loaded at room temperature.It was found that the fringe constant was extremely linear with wavelength for both types of loading and for the materials CT200, CT1200 and MY750. The stress optic coefficient did not change much between sheets of the same material but was markedly different between materials. The dispersion of birefringence was found to be approximately constant but showed evidence of anomalous dispersion.
Use of displacement data to calculate strain gauge response in non‐uniform strain fields
Authors: Schajer Gary S. 
Published: October 2008

AbstractA simple and effective method is described for calculating the strain indicated by a practical strain gauge mounted in a nonuniform strain field. The method uses integration or summation of the displacement field along the perimeter of the strain gauge area. This procedure gives results which are equivalent to those obtained by much lengthier calculations involving double integration of the strain field within the strain gauge area. The displacement summation method can easily take into account significant strain gauge design details such as number, length, width and spacing of the grid lines. The method also demonstrates that a strain gauge can be used as a displacement sensor as well as a strain sensor.
Plastic strain determination using peak speckle pattern intensity
Authors: Tay C.J. , Shang H.M. , Xu C.L. 
Published: October 2008

AbstractThis paper presents an integrated peak spectral intensity method for the measurement of plastic deformation in metallic materials. The method employs a laser speckle technique and a computer based image processing system. Test results on aluminium, brass and copper sheets subjected to bi‐axial stretching using the hydroforming process shows a correlation between the integrated peak spectral intensity coefficient Hi and the equivalent strain. In addition, the use of the parameter Hi requires less computation and enables measurement of plastic strains of up to 30%.
The behaviour of pressurised plain pipework subjected to simulated seismic loading
Authors: Moreton D.N. , Yahiaoui K. , Moffat D.G. , Machin H.C. , Amesbury L.A. 
Published: October 2008

AbstractA series of simulated seismic tests have been conducted using mild steel and stainless steel plain pipe specimens. These specimens were pressurised and subjected to fully reversed cyclic bending moments at frequencies of about 5 Hz. The bending moments and surface strains on the pipe wall were monitored and are reported here. Significant ratchetting was observed which, in the case of the mild steel specimens, lead to gross swelling and eventual failure. Although ratchetting was observed in the stainless steel specimens it was not so pronounced and failure appeared to be by low cycle fatigue.
The role of strain measurement technology in structural evaluation
Authors: Thomson J.F. 
Published: October 2008

AbstractThis paper describes the importance of structural evaluation to the process of design assessment and outlines the significant role played by strain measurement technology in extending the scope of strain history data collection and facilitating strain monitoring of full‐scale structures in the laboratory. After some general discussion of the various models of structural behaviour, it then proceeds to give a brief historical account and outlines the principles of thermoelastic stress analysis (TSA). A general desciption is provided of a specific TSA technique namely Stress Pattern Analysis by Thermal Emission (SPATE).Despite the level of innovation and development in strain measurement technology, the use of bonded strain gauge elements is still by far the most commonly used strain measurement and monitoring technique in structural evaluation work at NEL. The paper highlights several recent test programmes carried out at NEL in the form of case studies which demonstrate different aspects of measuring, monitoring and validation of this and other strain measurement techniques; and verification of analytical models.
Strain measurements using real time X‐ray images
Authors: Rutland Craig A. , Wang Ming L. 
Published: October 2008

AbstractRecent tests have shown that changes in densities within specimens can he seen when X‐ray images of the specimen are enhanced and compared. Prism specimens of aluminium and cement mortar were tested in uniaxial compression and simultaneously X‐rayed. The grey levels within images taken during loading are compared. Results show that the strains in the specimen can be determined from the change in grey levels.
Further assessment of numerical procedures for the study of fluid‐structure interaction
Authors: Haxton R.S , El‐Deeb K.M.M. , Royles R. , Hunter I.T. 
Published: October 2008

SynopsisA study of the doubly asymptotic approach (DAA) to fluid‐structure interaction was carried out using the PAFEC/Dolphins and STAGS/USA suites of programs. The particular problem simulated was that of a ring stiffened circular cylindrical underwater structure subjected to explosive pulses at standoff distances of the order of the diameter of the structure. The method of discretisation is described and response data obtained for selected nodes on the structure. Typical responses in the form of velocity‐time history and power spectral density are presented. Response in terms of stress is given also for a particular node as derived from adjacent elements in order to provide a check on the quality of the PAFEC/Dolphins numerical model. A coarse and fine modelling exercise with the STAGS/USA program demonstrated little change in the structural response in the areas of interest. Comparisons are made between the predictions of the two numerical codes, and a brief description is given of the experimental validation of the STAG/USA program. Future developments are discussed.
Local stiffening effect of ‘double deck’ bending strain gauges: part 1
Authors: Chen J.F. , Ooi J.Y. , Rotter J.M. 
Published: October 2008

AbstractIn stress measurement where it is difficult or impossible to access the inside surface of the structure, “double deck” (DD) or “sandwich” bending strain gauges can be used to measure both the membrane and bending strains. A DD gauge consists of a pair of constituent foil gauges which are bonded on the upper and lower surfaces of a plastic base or filling. It is mounted on the external surface of the test specimen to measure the external surface strain, and by extrapolation, the internal surface strain of the specimen. The sensitivity of the DD bending gauge increases when the separation between the pair of constituent foil gauges increases. However, this also increases the stiffness of the whole gauge. If the stiffness of the DD gauge is significant compared with that of the plate to which it is attached, the presence of the gauge may cause significant changes in local stiffness and result in errors of strain interpretation. This study is presented in two papers. Part I presents an approximate, analytical solution for the local stiffening effect of a DD gauge and quantifies the errors in the strain measurement. Part 2, to appear subsequently in Strain, will present the verification of the solution using a three dimensional finite element calculation, a parametric study and a correction method that can be applied easily. The extrapolation errors due to the stiffening effect and random reading noises are also explored.
Measurement of Y‐notch tip plastic zone by the laser speckle technique
Authors: Tay C.J. , Tay T.E. , Shang H.M. 
Published: October 2008

AbstractThis paper presents a laser speckle method for the measurement of plastic zone ahead of a Y‐notch tip on metallic specimens. The method employs an unexpanded laser beam to illuminate the test object. Diffracted images are captured on a ground glass and recorded using a CCD camera. The recorded images were digitised and subsequently analysed on a personal computer. The plastic strain at the notch tip was correlated with its corresponding speckle image using a recently proposed parameter known as the integrated peak spectral intensity coefficient. Specimens containing Y‐notches of various angles were tested and the resu Its compared well with that predicted by theory.
A single exposure reflection moiré interferometric technique for complete curvature analysis of bent plates
Authors: Subramanian G. , Subramanian A. 
Published: October 2008

AbstractMost known moiré methods need to be repeated three times for getting curvature information in three different in plane directions, for the complete analysis. To overcome this difficulty, a new single exposure moiré interferometric technique is proposed that maps completely partial curvature contours in three different directions of laterally loaded specularly reflecting plate models. Converging HeNe laser light is diffracted by a lens plane cross grating. The 00, + 10 and the +01 diffraction orders are permitted through the Fourier transform (FT) plane and collimated to illuminate the plate model. The reflected light from the loaded model records the model with the inherent deformed interferometric cross grating superimposed on it. A posteriori Fourier filtering of the developed recording (moirégram) gives partial curvature contours pertaining to three different in plane directions from which the principal curvatures and the principal directions are obtained. Also, this technique, being a single exposure technique, has the potential for complete bending analysis of plates subjected to lateral impact loading and destructive loading applications, where the repeatability of the event may not be possible.