77 resultados para POTENTIOSTATIC CURRENT OSCILLATIONS
em University of Queensland eSpace - Australia
Resumo:
This paper presents the results of an electrochemical study of the anodic characteristics of arsenopyrite in strongly alkaline solutions and of the cathodic reduction of ferrate( VI) and of dissolved oxygen at an arsenopyrite surface at potentials which are relevant to the oxidation reactions. Cyclic voltammetry at both arsenopyrite disc and arsenopyrite disc/platinum ring electrodes has shown that arsenic(III) is the main product of the anodic process at potentials in the region of the rest potential during oxidation by either ferrate( VI) or oxygen. Evidence for partial passivation of both the anodic and cathodic reactions has been obtained from potentiostatic current - time transients. The initial stage of oxidation by ferrate( VI) has been shown to be mass-transport controlled and this is also true of the oxidation by oxygen in dilute solutions of sodium hydroxide.
Resumo:
There are many changes and challenges facing the mental health care professional working in Australia in the 21st Century. Given the significance of their number and the considerable extent to which care is delivered by them, mental health nurses in particular must be at the forefront of the movement to enhance and improve mental health care. Mental health nurses in Australia must not only keep up with the changes, we should be setting the pace for others across the profession worldwide. The increasingly complex field of mental health nursing demands nurses who are not only equipped to face the challenges but are confident in doing so. Definitive guidelines for practice, clear expectations regarding outcomes and specific means by which to evaluate both practice and outcomes are vital. Strengthening the role and vision of mental health nursing so that there is clarity about both and highlighting core values by which to perform will enable us to become focused on our future and what we can expect to both give to and receive from our chosen profession and how we can, and do, contribute to mental health care. The role of the mental health nurse is undergoing expansion and there are new hurdles to overcome along with the new benefits this brings. To support this, nationally adopted, formalised standards of practice and means by which to measure these, i.e., practice indicators formerly known as clinical indicators, are required. It is important to have national standards and practice indicators because of the variances in the provision of mental health across Australia – different legislation regarding mental health policies and processes, different nursing registration bodies and Nursing Councils, for example – which create additional barriers to cohesion and uniformity. Improvements in the practice of mental health nursing lead to benefits for consumer outcomes as well as the overall quality of mental health care available in Australia. The emphasis on rights-based care, particularly consumer and carer rights, demands evidence-based, up-to-date mental health care delivered by competent, capable professionals. Documented expectations for performance by nurses will provide all involved with yardsticks by which to evaluate outcomes. Flowing on from these benefits are advances in mental health care generally and enhancements to Australia’s reputation and position within the health care arena throughout the world. Currently, the ‘Standards for Practice’ published by the Australian New Zealand College of Mental Health Nurses (ANZCMHN) in 1995 and the practice indicators developed by Skews et al. (2000) provide a less formal guide for mental health nurses working in Australia. While these earlier standards and practice indicators have played some role in supporting mental health nurses they have not been nationally or enthusiastically adopted and there are a multitude of reasons for this. This report reviews the current literature available on practice indicators and standards for practice and describes an evidence-based rationale as to why a review and renewal of these is required and why it is important, not just for mental health nurses but to the field of mental health in general. The term ‘practice indicator’ is used, except where a quotation utilises ‘clinical indicator’, to more accurately reflect the broad spectrum of nursing roles, i.e. not all mental health nursing work involves a clinical role.
Resumo:
Examines the state of current affairs television in Australia today by pondering the future, while drawing lessons from the past. The book questions the social and political value of what we now think of as current affairs journalism.
Resumo:
The nonlinear response of a chaotic system to a chaotic variation in a system parameter is investigated experimentally. Clear experimental evidence of frequency entrainment of the chaotic oscillations is observed. We show that analogous to the frequency locking between coupled periodic oscillations, this effect is generic for coupled chaotic systems.
Resumo:
We investigate a nondestructive measurement technique to monitor Josephson-like oscillations between two spatially separated neutral atom Bose-Einstein condensates. One condensate is placed in an optical cavity, which is strongly driven by a coherent optical field. The cavity output field is monitored using a homodyne detection scheme. The cavity field is well detuned from an atomic resonance, and experiences a dispersive phase shift proportional to the number of atoms in the cavity. The detected current is modulated by the coherent tunneling oscillations of the condensate. Even when there is an equal number of atoms in each well initially, a phase is established by the measurement process and Josephson-like oscillations develop due to measurement backaction noise alone.
Resumo:
A method for the accurate computation of the current densities produced in a wide-runged bi-planar radio-frequency coil is presented. The device has applications in magnetic resonance imaging. There is a set of opposing primary rungs, symmetrically placed on parallel planes and a similar arrangement of rungs on two parallel planes surrounding the primary serves as a shield. Current densities induced in these primary and shielding rungs are calculated to a high degree of accuracy using an integral-equation approach, combined with the inverse finite Hilbert transform. Once these densities are known, accurate electrical and magnetic fields are then computed without difficulty. Some test results are shown. The method is so rapid that it can be incorporated into optimization software. Some preliminary fields produced from optimized coils are presented.
Resumo:
The effect of incoherent interlayer transport on the interlayer resistance of a layered metal is considered. We find that for both quasi-one-dimensional and quasi-two-dimensional Fermi liquids the angular dependence of the magnetoresistance is essentially the same for coherent and incoherent transport. Consequently, the existence of a three-dimensional Fermi surface is not necessary to explain the oscillations in the magnetoresistance that are seen in many organic conductors as the field direction is varied. [S0031-9007(98)07660-1].
Resumo:
Although oral piercing has been an uncommon practice in the Western world, the insertion of metal objects into intra-oral and peri-oral pierced sites is growing in popularity. Tongue piercing is one such practice whereby a metal barbell is inserted into the tongue after piercing with a 14-16 gauge needle. Pain, swelling and infection are the most serious consequences associated with this procedure. Other adverse outcomes include mucosal or gingival trauma, chipped or fractured teeth, increased salivary flow, calculus build-up, and interference with speech, mastication and swallowing. This article presents a case report on tongue piercing and highlights the procedure involved. Special attention is given to complications and dental implications associated with such an unusual practice.
Resumo:
We consider the magnetoresistance oscillation phenomena in the Bechgaard salts (TMTSF)(2)X, where X = ClO4, PF6, and AsF6 in pulsed magnetic fields to 51 T. Of particular importance is the observation of a new magnetoresistance oscillation for X = ClO4 in its quenched state. In the absence of any Fermi-surface reconstruction due to anion order at low temperatures, all three materials exhibit nonmonotonic temperature dependence of the oscillation amplitude in the spin-density-wave (SDW) state. We discuss a model where, below a characteristic temperature T* within the SDW state, a magnetic breakdown gap opens. [S0163-1829(99)00904-2].
Resumo:
A quantum Markovian master equation is derived to describe the current noise in resonant tunneling devices. This equation includes both incoherent and coherent quantum tunneling processes. We show how to obtain the population master equation by adiabatic elimination of quantum coherences in the presence of elastic scattering. We calculate the noise spectrum for a double well device and predict subshot noise statistics for strong tunneling between the wells. The method is an alternative to Green's function methods and population master equations for very small coherently coupled quantum dots.