Ellen Fletcher

Australian Catholic University | ACU

On 1998 December 12 a new trans-Neptunian object, 1998 XY95, was discovered as part of a deep search. Recent observations of this object have placed it amongst the class of objects known as the scattered trans-Neptunian objects (TNOs). A total of 39 CCD images of 1998 XY95 were taken over two nights, and these were used to search for a light curve,...

We have obtained a number of CCD images of two trans-Neptunian objects, 1994 VK8 and 1996 TP66, over two nights. The changes in magnitude of these objects have been examined, in a search for periodic variation. In the case of 1996 TP66, nothing other than random noise can be found to within the errors of ∼0.04 mag. Although a periodic signal is fou...

The population of stellar-like objects, not massive enough to burn hydrogen like normal stars, are known as brown dwarfs. But how low-mass can these mysterious objects be? Also, how many of the lowest-mass brown dwarfs are, as yet, undetected in our Galaxy, or indeed, in other galaxies? To search for more of these elusive objects, the authors have...

Available from the Minor Planet Center.

Available from the Minor Planet Center.

Angular velocity expressed in radians/sec of the rotation movement of the QRS loop at intervals of 2.5 msecs was calculated from a computer program written in Fortran IV. Frontal, horizontal and left sagittal planes were recorded in 125 normal subjects for analysis. The range of angular velocity for 375 QRS loops was from a few radians/sec to a max...

Summary Histo-Pathological studies have demonstrated the essential focal nature of AV conduction disturbances, but current clinical concepts of heart block, derived from the scalar electrocardiogram, give little or no information as to the precise site within the conducting system where impulses are delayed or blocked. The His bundle electrogram re...

SUMMARY Twenty-one patients have been monitored using oesophageal electrocardiography to determine the site of origin of eaopic rhythms occurring during oral surgery. It has been confirmed that in twelve patients these arose in the junctional system of the heart. One patient developed a bidirectional junctional tachycardia which is considered to be...

A total of 24 patients with heart block revealed by scalar electrocardiography was studied using the His bundle electrogram. Four groups of disturbed conduction are described which include various types of heart block, partial and complete, at different sites, single and multiple, in the specialized conducting system. These are (1) intra-atrial blo...

The central and peripheral vascular haemodynamic effects of glucagon were studied in 29 patients. With a single dose method of 2 or 5 mg. glucagon intravenously the inotropic action of the drug produced immediate increased myocardial contractility with significant increase in cardiac output and enhanced cardiac performance, and lowering of pulmonar...

To determine whether high-pressure hydrogen gas will adversely affect the steel in a proposed hydrogen-gas-transmission system, IGT and Battelle Columbus Laboratories assessed the potential for hydrogen attack, blistering, ductility loss, hydrogen-stress cracking, and hydrogen-environment embrittlement in (1) existing pipelines, (2) future pipeline...

Because introduction of hydrogen during bright-cadmium electroplating of high strength steels causes hydrogen-stress cracking, a program was undertaken to evaluate various processes and materials. Report describes effectiveness of inhibitors for reducing hydrogen absorption by steels.

Intravenous lignocaine (1 mg./kg. body weight) was found to produce insignificant haemodynamic changes, and in particular no reduction in myocardial contractility. A rate of 2 mg./minute infused intravenously is suggested for therapeutic purposes.In anaesthetized dogs an infusion of 13.5 mg./minute caused moderate haemodynamic depression and a maxi...

Hydrogen embrittlement and stress cracking studied on 14 selected high strength alloys

Five cases of the Eisenmenger-ductus syndrome are presented. The difficulties in clinical diagnosis, especially with regard to auscultatory findings, are discussed. The reactive hyperaemia test may reveal differential cyanosis of the hands. The anatomical diagnosis was confirmed by cardiac catheterisation and angiocardiography. At present treatment...

Literature review on pickling inhibitors and cadmium electroplating processes to minimize hydrogen absorption by ultrahigh strength steels

Hydrogen-stress cracking in high-strength steels is influenced by hydrogen content of the material and its hydrogen absorption tendency. Non-embrittling cleaning, pickling, and electroplating processes are being studied. Protection from this hydrogen embrittlement is important to the aerospace and aircraft industries.

This report deals with the deleterious effects of hydrogen gas on steel at elevated temperatures and/or pressures. Hydrogen attack on steels is manifest as decarburization, intergranular fissuring, or blistering. These conditions result in lowered tensile strength, ductility, and impact strength. The reaction of hydrogen with iron carbide to form m...

Steel which is subjected to a tensile stress exceeding some critical value depending on the strength level of the steel and which contains hydrogen that is free to move is susceptible to failure in a delayed, brittle manner. The problem is especially serious because the minimum stress for failure decreases as the strength of the steel is increased...

The effects of adding 0.012, 0.09, 0.17, and 0.35% Nb to a 0.35% carbon steel were investigated. The study of response to heat treatment included determining the effects of Nb on the grain-growth, carbide- solution, hardenability, and tempering characteristics of this heat-treatable steel. Nb was found to provide a strong resistance to grain gr...

Cast X-40 alloy with a 0.010 wt.% nitrogen content had a 100-hr ruplure stress at 1500 deg F of about 28,200 psi. Increases in nitrogen content progressively decreased the rupture strength, and with about 0.09 to 0.15 wt.% N, a minimum strength of 25,600 psi was reached, but there was no accompanying change in microstructare. Further increases...

Summary The effect of intramuscular Digoxin on 20 cases is analysed. The glycoside is rapidly absorbed from muscle, and the results indicate that the intramuscular route is an efficient substitute for intravenous therapy when urgent parenteral digitalisation is required. In undigitalised adults a suitable initial dose is 1 mg. and maximum therapeut...

A metallographic and x-ray diffraction study of the Co-Cr binary diagram and a study of the effect of ternary additions were undertaken for a structural analysis of Vitallium alloys. The following sluggish transformation reactions were indicated: (1) Cr and Mo raised the alpha-beta transformation temperature in the Co-Cr systems; (2) N, Fe, and Ni...

This paper describes a metallographic investigation of the influence of tungsten or molybdenum additions upon the transformation and precipitation reactions occurring in Co-rich Co-Cr alloys. It is shown that tungsten has little effect upon the α-β transformation temperature range, while molybdenum tends to raise it. Both elements tend to promote t...

Summary Over the past 3 years we have used oximetry and85krypton to detect and estimate quantitatively the degree of left-to-right shunting in patients with congenital heart disease. The85krypton test is simple and gives excellent differentiation between patients with and without such shunts, and there is no overlap between the two groups. The resu...