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The accurate differentiation of a ventricular from a supraventricular origin of a wide QRS tachycardia (QRS > 120 milliseconds) is an important clinical problem. Misdiagnosis of this arrhythmia can lead to institution of inappropriate drug therapy acutely with potentially catastrophic consequences. Various diagnostic aids have been used to obtain electrocardiographic potentials to aid in the differentiation. This report assesses the clinical usefulness of oesophageal electrocardiography in the differentiation of wide complex tachycardias and describes a simple, safe technique to obtain oesophageal electrocardiograms. Eighteen consecutive patients between the ages of 27 and 71 years who were haemodynamically stable were selected for this study. The technique was performed in the following manner: A temporary pacing catheter was lubricated and passed nasally and advanced with the patient being instructed to swallow. Adjustments in catheter depth were made as necessary to obtain an optimal recording on a standard electrocardiograph recorder. Satisfactory placement with minimal patient discomfort was achieved within 6.5 minutes (average 4.5 minutes) in all cases. High quality tracings were obtained in every instance. In the 18 patients with tachyarrhythmia, AV dissociation consistent with ventricular tachycardia was demonstrated in 11 instances; in the remainder the diagnosis was supraventricular tachycardia. Of the 11 patients diagnosed as ventricular tachycardia, 9 were initially misdiagnosed as supraventricular tachycardia, whilst only 1 of 7 patients with supraventricular tachycardia was misdiagnosed. This study has demonstrated that oesophageal electrocardiography is useful in the differentiation of wide complex tachycardias. The technique outlined in this report is simple and offers the following advantages: the temporary pacing catheter is associated with minimal discomfort; the catheter allows easy manoeuverability within the oesophagus which allows proper depth to be easily obtained; the equipment used is routinely available. Therefore the technique offers a rapid, safe and simple method of obtaining an oesophageal electrocardiogram which is invaluable in the electrocardiographic differentiation of a wide complex tachycardia. / Thesis (M.Med.)-University of Natal, Durban, 1990.

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<p><font face="Arial"> <p align="left">In this study, the capabilities of Neutron Radiography (NRad) and -Tomography (NTomo), as well as X-ray Radiography (XRad) to investigate chlorides and chlorides corrosion effects within steel reinforced laboratory concrete samples are practically explored. Capabilities of Scanning Electron Microscopy (SEM), Prompt Gamma Neutron Activation Analysis (PGNAA), Particle Induced X-ray Emission (PIXE), Small-Angle Neutron Scattering (SANS), Neutron Diffraction (NDIFF) and X-ray Diffraction (XDIFF) analytical techniques are also explored through review of literature.</p> </font></p>

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Radiography is an extensively used NDT method, especially in nuclear, aerospace and automotive industries where optimal designs call for greater reliability. The rules corresponding to industrial radiography are defined in a system of radiographic standards. The standards related to the radiographic testing of metallic welded joints had been harmonised in all over the Europe and at the end in 1997, the standard &quot / EN 1435&quot / was established and published. Since then, this standard has become the most widely used standard where the radiographic applications are necessary. To eliminate the person based errors during application of the standard, moreover to save time, cost and effort in radiographic exposures, in this study it was aimed to write a computer program which is able to calculate all necessary parameters for a radiographic exposure related to this standard EN 1435. In the programming stage, Visual Basic 6.0 &amp / #61651 / was used. The program consists of many windows, each giving and controlling separate parameters related to the exposure. Besides giving all the needed parameters, the evolved program is able to prepare a report with these parameters. So, both radiography technicians and experts can use it. It is believed that this study constructs a basis for developing other computerised test procedures for any kind of non-destructive testing methods used in industry today.