Precise calibration method for triaxial magnetometers not requiring Earth's field compensation

A calibration procedure for calibrations of triaxial magnetometers is presented. The procedure uses a triaxial Helmholtz coil system and an Overhauser scalar magnetometer and is performed in the an Earth's field range. The triaxial coils are firstly calibrated with the help of the Overhauser magnetometer and subsequently a calibration of a digital triaxial magnetometer calibration is performed. As opposed to other approaches, neither Earth’s field nulling system is needed, nor are movements of the magnetometer are needed. A real calibration test was carried out and the extended uncertainty was better than 430 ppm in sensitivity and 0.06 degrees in orthogonality

Determination of the Overhauser magnetometer uncertainty

Overhauser magnetometers are the basic instruments for scalar measurements; however, their accuracy is determined at the time of manufacture only. Because of various effects affecting the gyromagnetic ratio of the used fluid or the stability of the oscillators in the circuitry, their accuracy should be verified during the instrument lifetime. Specific methodology of data processing and determination of the Overhauser magnetometer uncertainty is described in this paper

Superimposed Infectious Colitis in Crohn’s Disease

The differential diagnosis for an acute Crohn’s flare should include enteric infection, a challenging yet critical distinction to make when determining appropriate therapy. Since both present similarly, identification of an enteric infection should be performed with comprehensive stool microbial testing. In the setting of moderate-to-severe disease, patients on biologic therapy may be more prone to infectious complications. We present a patient with chronic Crohn’s disease with an unusual, previously undetected enteric infection due to Plesiomonas shigelloides. Once identified, appropriate antibiotic treatment led to resolution of the patient’s acute symptomatology. This is the first reported case of P. shigelloides infection in Crohn’s disease

Determining the design parameters for geosynthetic reinforcements subject to multi-stage actions using the isochronous strain energy approach

Geosynthetic-reinforced soil structures may be required to resist multi-stage actions, such as sustained plus traffic loading or sustained plus seismic loading. Current design codes/methods do not recognise possible differences that may exist between the response of geosynthetics to multi-stage actions and to single-stage actions. In this paper, it is suggested that the isochronous strain energy approach can be used to better interpret the load–strain–time behaviour of geosynthetics subject to multi-stage actions. Test data from sustained plus cyclic loading and sustained plus short-term loading are presented and analysed using the isochronous strain energy approach. Based on these analyses, two design methods are developed to take account of the various responses of geosynthetics to different forms of multi-stage loading. </jats:p

Determining the design parameters for geosynthetic reinforcements subject to single-stage actions using the isochronous strain energy approach

Geosynthetic-reinforced soil systems are required to resist a variety of actions during their design lifetime. These actions may act over different periods of time, and they may be sustained or transient in nature. Furthermore, these actions may be applied to the structure either singularly or in combination. This paper describes the implications of single actions, applied over a substantial period of the design lifetime, termed ‘single-stage actions’. The current practice for the determination of design parameters for geosynthetic-reinforced soil structures (GRSSs) subject to single-stage actions is described in detail, with special consideration given to the determination of reference strengths, factors of safety or partial factors, and design strengths. It is shown that the recently developed isochronous strain energy (ISE) approach may be used to overcome the problems associated with material characterisation within the current design methods/codes. The determination of reference strengths, factors of safety or partial factors and design strengths based on the ISE approach is shown, and compared with the current practice. Finally, it is shown that the design strength determined using the ISE approach takes account of both time and strain level dependence where this occurs. </jats:p

Superimposed Infectious Colitis in Crohn’s Disease

The differential diagnosis for an acute Crohn’s flare should include enteric infection, a challenging yet critical distinction to make when determining appropriate therapy. Since both present similarly, identification of an enteric infection should be performed with comprehensive stool microbial testing. In the setting of moderate-to-severe disease, patients on biologic therapy may be more prone to infectious complications. We present a patient with chronic Crohn’s disease with an unusual, previously undetected enteric infection due to &lt;i&gt;Plesiomonas shigelloides.&lt;/i&gt; Once identified, appropriate antibiotic treatment led to resolution of the patient’s acute symptomatology. This is the first reported case of &lt;i&gt;P. shigelloides&lt;/i&gt; infection in Crohn’s disease. </jats:p

The isochronous strain energy approach applied to the load–strain–time–temperature behaviour of geosynthetics

The load–strain–time–temperature behaviour of geosynthetics can be determined by a variety of strength-testing methodologies. However, to date it has not been possible to directly compare and correlate the data obtained from different testing regimes in a generally applicable manner. In this paper, a strain energy approach to the characterisation of the load–strain–time–temperature of geosynthetics is developed that is intended to deal with this problem. This approach takes account of the changes in the behaviour of geosynthetics that occur with time, and is called the isochronous strain energy (ISE) approach. The background to the ISE approach is set out and used to compare and correlate the data from various strength tests carried out on a wide range of geosynthetics. This shows that the isothermal load–strain–time behaviour of a geosynthetic can be represented in a generally applicable manner within an ISE–time plot and that temperature effects can be represented within ISE–time–temperature plots. It is shown that the ISE absorbed by a geosynthetic comprises two basic components, the immediately recoverable ISE and the locked-in ISE. Representation of the behaviour of geosynthetics using these two ISE components allows the prediction of their response to any loading regime applied over any time period. </jats:p