Studies of the radiation emitted by short duration electrical discharges

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Experimental simulations of the weathering of volcanic ash : a case study to better understand short- and long-term impacts of ash-leachable elements on the environment : a thesis presented in the partial fulfilment of the requirements for a degree of Master of Science in Earth Science at Massey University, Palmerston North, New Zealand

The aim of this project is the development and testing of a new methodology for the investigation of the short- to long-term leaching behaviour of volcanic ash. Previous research has demonstrated that volcanic eruptions can have strong impacts on the environment, which result from elements that have been leached from volcanic ash. To date, there is relatively little understanding of the minor and trace element composition of ash-leached brines, and how this varies over time. These gaps in knowledge currently preclude an estimate of both the detrimental and the beneficial impacts of volcanic ash fall due to leaching on the environment, agriculture, as well as on human and animal health. An adaption of a soxhlet reactor was found to be an adequate experimental technique for the constant flushing of volcanic ash samples with deionised water. This was designed to accelerate the weathering of a volcanic material in a laboratory setting. A number of shortcomings in the experimental method could be identified through the course of this research and should be considered in future investigations. In this experiment nine volcanic ash samples from four different and highly active volcanoes have been tested. These volcanoes are Mt. Ruapehu and White Island in New Zealand, Mt. Kelut in Indonesia and Mt. Sakurajima in Japan. All volcanic ash samples were found to release elements into brine over the experimental time in a strongly non-linear fashion. Based on the current data set of nine ash samples, three main classes of time-variant element release behaviour are here suggested and defined, whose characteristics are primarily controlled by the element, rather than volcanic source or ash characteristics. A preliminary interpretation of these different element release pattern is that their temporal changes are most likely restrained by the strength of chemical and mechanical bond of elements to the surface of juvenile and non-juvenile ash material. Moreover, significant controls on the long-term leaching concentrations of elements were found to be by the style of eruption as well as the nature of the volcano plumbing system, confirming results of earlier batch leaching experiments. The 1995-96 Mt. Ruapehu eruption sequence in particular illustrated some significant variability in leaching behaviour as a result of specific eruption parameters. Volcanic ash samples that have been derived from a phreatomagmatic style eruption have been found to have a higher short-to long-term impact than those volcanic ash samples derived from dry magmatic eruptions. A simple method was developed to estimate the real–world equivalent weathering time corresponding to the duration of a soxhlet reactor leaching experiment. The method, which is primarily based on the total volume of water percolating through an ash sample, and to relate this to local annual rain fall data, was found to estimate real-world weathering times in the natural environment fairly accurately. Based on these natural time constraints, detrimental short-term impacts (months to years) are concluded for lead and fluoride, and beneficial short-term impacts for calcium and manganese. Long-term beneficial effects (up to 20 years) are seen for zinc, copper and iron, while long-term detrimental impacts are concluded for the cases of lead and fluoride. The strong dependence of the leaching rate on the effective ash surface area precludes that future forecasts of short- and long-term impacts should be made by considering local soil permeability and ash grain-size characteristics. In that way future modelling approaches via reactive and non-reactive porous media flow of ash-leached brines into soil and groundwater may form an interesting avenue for future developments of this pilot study. This approach may hold potential to give quantitative advice to regional councils, the agricultural industry and governmental agencies on detrimental and beneficial short- to long-term impacts of volcanic ash

Field resolution tests with the Metrogon lens

The first portion of this treatise is devoted to a compilation of general knowledge concerning photographic resolution testing - an explanation of certain optical terms; the drafting of resolution targets; methods for averaging resolution values, measured at various positions on the format, to obtain one over-all value for an exposure; and a description of the factors involved in conducting the photographic operations. In the second part of the paper, analyses of the results obtained from line-target resolutions are made with the purpose of determining those combinations of aperture, filter, and shutter speed which result in high photographic resolutions. This information will be of particular value to a person who is called upon to operate the camera, but whose knowledge of photography is limited. The final section includes a determination of that position of photographic focus in an aerial camera which produces best over-all definition. All phases of the resolution testing program described herein require no complex scientific equipment other than cameras for their execution. This system of testing produces adequate data and is sufficiently simple to warrant its consideration as a field method in which trained laboratory personnel, although desirable, are not essential for its accomplishment --Introduction, page 4

A comparison of the use of Polaroid and colored filters in the multiplex aeroprojector

The purpose of this thesis is the drawing of a comparison between the use of the colored filters, which are normally employed in the multiplex aeroprojector by various mapping agencies throughout the country, and the use therein of Polaroid filters. The filters in the aeroprojector serve to break the projection of a stereoscopic pair of photographs into two impressions which are viewed separately by each eye of the observer, thus providing the main requirement for the observance of a three-dimensional effect. this stereoscopic effect is utilized in the multiplex plotting machine for the delineation of contours...In order to form a suitable foundation for the research to follow, it has been deemed worthwhile to include several chapters at the beginning of this thesis which deal with such subjects as the fundamentals of photogrammetry, the use of the multiplex aeroprojector, the principles of stereoscopy, and the theory of light polarization --Preface, page ii-iv

Nursing and euthanasia : a narrative review of the nursing ethics literature

Background: Medical Assistance in Dying, also known as euthanasia or assisted suicide, is expanding internationally. Canada is the first country to permit Nurse Practitioners to provide euthanasia. These developments highlight the need for nurses to reflect upon the moral and ethical issues that euthanasia presents for nursing practice. Purpose: The purpose of this article is to provide a narrative review of the ethical arguments surrounding euthanasia in relationship to nursing practice. Methods: Systematic search and narrative review. Nine electronic databases were searched using vocabulary developed from a stage 1 search of Medline and CINAHL. Articles that analysed a focused ethical question related to euthanasia in the context of nursing practice were included. Articles were synthesized to provide an overview of the literature of nursing ethics and euthanasia. Ethical Considerations: This review was conducted as per established scientific guidelines. We have tried to be fair and respectful to the authors discussed. Findings: Forty-three articles were identified and arranged inductively into four themes: arguments from the nature of nursing; arguments from ethical principles, concepts and theories; arguments for moral consistency; and arguments from the nature of the social good. Key considerations included nursing's moral ontology, the nurse-patient relationship, potential impact on the profession, ethical principles and theories, moral culpability for acts versus omissions, the role of intention and the nature of the society in which euthanasia would be enacted. In many cases, the same assumptions, values, principles and theories were used to argue both for and against euthanasia. Discussion: The review identified a relative paucity of literature in light of the expansion of euthanasia internationally. However, the literature provided a fulsome range of positions for nurses to consider as they reflect on their own participation in euthanasia. Many of the arguments reviewed were not nursing-specific, but rather are relevant across healthcare disciplines. Arguments explicitly grounded within the nature of nursing and nurse-patient relationships warrant further exploration

New nitric oxide donor drugs

Nitric oxide is a recognised dilator of vascular smooth muscle and therefore is central in the control of blood flow. A lack of blood flow in humans can have very important implications in a number of disorders of both cutaneous tissue and internal circulation. In this thesis we look at the synthesis of new nitric oxide donors, their stabilities and their possible medicinal usage. These donors have been based on the S-nitrosothiol group, connected to sugar moieties, simple amino acids or linked glycoaminoacids. The donors prepared have been used to investigate the skin blood flow and localised responses to nitric oxide, proving that NO has an important role in the maintenance of healthy skin. These will be further investigated as possible treatments for disorders involving a lack of cutaneous blood flow, such as connective tissue disorders and the repeated ulceration often seen in diabetic patients. A set of clinical trials have been carried out comparing the responses of healthy patients and sufferers of Raynaud's Phenomenon to exogenous nitric oxide. In this we have highlighted a number of differences and have helped to determine a possible cause of the disorder. We have prepared a number of slow release NO donors which have been shown to produce a sustained vasodilatory response in blood vessels with removed or damaged endothelial cells. These show promise for use in the treatment of patients with circulatory disorders, especially for subjects following treatment for atherosclerosis. Basic studies investigating the stabilities of these compounds have been carried out, in order to aid our understanding of their mode of breakdown

How does priority setting for resource allocation happen in commissioning dental services in a nationally led, regionally delivered system: a qualitative study using semistructured interviews with NHS England dental commissioners

Objectives: To understand approaches to priority setting for healthcare service resource allocation at an operational level in a nationally commissioned but regionally delivered service. Design: Qualitative study using semistructured interviews and a Framework analysis. Setting: National Health Service dentistry commissioning teams within subregional offices in England. Participants: All 31 individuals holding the relevant role (dental lead commissioner in subregional offices) were approached directly and from this 14 participants were recruited, with 12 interviews completed. Both male and female genders and all regions were represented in the final sample. Results: Three major themes arose. First, 'Methods of priority setting and barriers to explicit approaches' was a common theme, specifically identifying the main methods as: perpetuating historical allocations, pressure from politicians and clinicians and use of needs assessments while barriers were time and skill deficits, a lack of national guidance and an inflexible contracting arrangements stopping resource allocation. Second, 'Relationships with key stakeholders and advisors' were discussed, showing the important nature of relationships with clinical advisors but variation in the quality of these relationships was noted. Finally, 'Tensions between national and local responsibilities' were illustrated, where there was confusion about where power and autonomy lay. Conclusions: Commissioners recognised a need for resource allocation but relied on clinical advice and needs assessment in order to set priorities. More explicit priority setting was prevented by structure of the commissioning system and standard national contracts with providers. Further research is required to embed and simplify adoption of tools to aid priority setting