55 research outputs found
Recent theoretical progress in treating electron impact ionization of molecules
No full text(e,2e) ionization differential cross sections are presented for several molecules. We will compare experimental results with theoretical calculations using the molecular three body distorted wave (M3DW) approximations for H2, N2, H2O and Formic Acid (FA) using better wave-function for the molecules than we had in previous works. Generally, good agreement is found between the M3DW approach and experiments.Ola Al-Hagan, Chuangang Ning, Kate Nixon, Andrew Murray, Christopher Colyer, Mark Stevenson, Birgit Lohmann and Don Madiso
(e,2e) study of two-center interference effects in the ionization of N(2)
No full textA number of previous studies have suggested the possibility of two-center interference effects in the single ionization of diatomic molecules such as H2 and N2. While interference effects have been successfully observed in the ionization of H2, to date evidence for interference in N2 ionization has yet to be conclusively demonstrated. This study presents triply differential cross sections for electron impact ionization of N2, measured using the (e,2e) technique. The data are probed for signatures of two-center interference effects. Evidence for interference manifesting in the cross sections is observed.L. R. Hargreaves, C. Colyer, M. A. Stevenson, B. Lohmann, O. Al-Hagan, D. H. Madison and C. G. Nin
Electronic collisions with molecules of biological relevance.
No full textExperimental studies of radiation damage in living tissue indicate that it is not just the primary ionizing particle responsible for the bulk of the radiation damage, but also secondary species generated by the ionizing particle. There is much interest in how these secondary particles, commonly electrons, interact with bio-molecules and in particular DNA. In this thesis, I report relative triple differential cross section measurements for the electron impact ionization of formic acid, tetrahydrofuran and thymine. Formic acid can be considered one of the simplest building blocks for biological systems, particularly in the formation of glycine and amino acids. Tetrahydrofuran is a simple ring structure that can be used as a good approximation to the sugar component of the deoxyribose backbone. Thymine, together with cytosine, guanine and adenine, are the DNA bases and their interactions with electrons are considered to be of great importance. Single differential cross sections for elastic electron interactions with cytosine and thymine are also reported.Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 201
Dynamical (e, 2e) studies using tetrahydrofuran as a DNA analog
No full textTriple differential cross sections for the electron-impact ionization of the outer valence orbital of tetrahydrofuran have been measured using the (e, 2e) technique. The measurements have been performed with coplanar asymmetric kinematics, at an incident electron energy of 250 eV and at an ejected electron energy of 10 eV, over a range of momentum transfers. The experimental results are compared with theoretical calculations carried out using the molecular three-body distorted wave model. The results obtained are important for gaining an understanding of electron driven processes at a molecular level and for modeling energy deposition in living tissue.C. J. Colyer, S. M. Bellm, B. Lohmann, G. F. Hanne, O. Al-Hagan, D. H. Madison and C. G. Nin
MORPHOLOGICAL OBSERVATIONS OF THE DECIDUOUS DENTITION IN THE FUR SEAL (Callorhinus ursinus)
No full textIn the previous papers concerned with the fetal dentition of the fur seal, the author described that the deciduous teeth are very small and are simple in shape and that they have completely shed during the period of the intra-uterine life (β61a, b). The mammalian deciduous tooth has not been studied yet in detail except for that of the human and some animals (Diff rich,β60), but the permanent tooth has been widely investigated by many workers (Owen, 1840-45; Terra, β11; Mummery,β24; Colyer, '36; Wiclcloson,β39; Scheffer,β51, β60; Chaison,β57; Fujita, '57; Scott and Symons, β61; etc.).journal articl
Learning theories and interprofessional education: a user's guide
No full textThere is increasing interest in the theoretical underpinning of interprofessional education (IPE) and writers in this field are drawing on a wide range of disciplines for theories that have utility in IPE. While this has undoubtedly enriched the research literature, for the educational practitioner, whose aim is to develop and deliver an IPE curriculum that has sound theoretical underpinnings, this plethora of theories has become a confusing, and un-navigable quagmire. This article aims to provide a compass for those educational practitioners by presenting a framework that summarizes key learning theories used in IPE and the relationship between them. The study reviews key contemporary learning theories from the wider field of education used in IPE and the explicit applications of these theories in the IPE literature to either curriculum design or programme evaluation. Through presenting a broad overview and summary framework, the study clarifies the way in which learning theories can aid IPE curriculum development and evaluation. It also highlights areas where future theoretical development in the IPE field is required
Dose uncertainties associated with a set density override of unknown hip prosthetic composition
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Kata physin : a critical exploration of the epistemology of T. F. Torrance as it relates to the philosophy of theological and natural science
No full textAccording to T. F. Torrance, all authentic knowledge involves the nature of the object impressing its inherent rationality on our minds. Consequently, knowledge involves thinking in accordance with the nature of the object given for thought. Given that this epistemological position is not presuppositionless, we shall explore the place and function of "ultimate beliefs" in Torrance's epistemology, as well as the question as to whether such beliefs imply a retreat to either foundationalism or fideism.
The inescapability of ultimate beliefs in all human knowledge requires a shift in the traditional notion of objectivity. Consequently Torrance's understanding of objectivity, and the reasons for his insistence that the subject-object relation cannot be transcended, are analyzed. Additionally, our ability to keep our tendency toward subjectivity in check is considered. It is also argued that Torrance's epistemological position implies an alternative notion of truth. Drawing on distinctly Christian sources, Torrance emphasizes the distinction between truth and truthfulness thereby reorienting the discussion from a focus on statements to a focus on being. This shift challenges the dichotomy between correspondence and coherence theories of truth and provides one way of transcending the scientific realism/anti-realism debate. Torrance's position on truth is located relative to other well-known thinkers.
Torrance's epistemological convictions give rise to a practical epistemological tool, disclosure models. These function as self-correcting, self-marginalizing lenses through which we encounter reality, allowing it to disclose itself to us. It is this constant disclosure and revision that enables our concepts to remain rooted in reality and yield knowledge in accordance to the nature of the thing known
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