Examination of the material removal mechanisms during the lapping process of advanced ceramic rolling elements

Two types of HIPed Si3N4 bearing ball blanks with different surface hardness and fracture toughness were lapped under various loads, speeds, and lubricants using a novel eccentric lapping machine. The lapped surfaces were examined by optical microscope and SEM. The experimental results show that the material removal rate for type I ball blanks were 3-4-fold of type 2 in most cases. Different lapping fluids affected the material removal rate at lower lapping loads, but they had much less influence on the material removal rate at higher lapping loads. The SEM micrographs reveal that the grain pullout prevailed on the lapped surface of type I ball blanks, and the surface of type 2 featured bulk material removal by microcracking. Under extreme high lapping load, surface cracks and damages were found, and SEM with EDX disclosed steel from the lapping plate had transferred to the ceramic ball surface. The preliminary conclusion is that the material removal mechanism during the lapping process of silicon nitride balls using this eccentric lapping machine is mainly mechanical abrasive wear. Lawn and Wilshaw's indentation model on brittle materials is used to explain the difference in material removal rate for the two types of ball blanks

Ecological history and the development of peat on the central watershed of the north Yorkshire Moors

The peat deposits of a limited area of the North Yorkshire Moors were studied through pollen analysis and associated techniques. The aim of the project was to provide details about the inception of peat growth and man's effect on the vegetation of the area throughout time. Altogether thirteen sites were examined and pollen diagrams constructed from the results. The pollen diagrams gave an outline of the conditions which prevailed on the North Yorkshire Moors from about 6000 years B.P. up to the present day, and showed that the influence of man on the vegetation of the area was very marked. The active removal of woodland by man is seen in three major phases which have been tentatively assigned to the cultural periods of the Neolithic, Bronze Age and Mediaeval. In addition to these three phases, burning of the vegetation appears to have taken place continuously on the upland areas of the moors from the start of peat accumulation. From this it is suggested that man played a part in the formation of the upland peat deposits, although probably only in the role of assisting in the degradation of an already 'poor’ environment. The effects of man, which are so clearly reflected in the pollen diagrams of the present study, appear to rule out the possibility of widespread climatically induced vegetation changes for most of the period under examination. It is concluded that while a great deal of new information on the historical ecology of the area has been revealed a great many gaps in knowledge still remain. However, the study provides for a better understanding of an environment created by man through many thousands of years of mis/use, and this information may assist in the formulation of an appropriate conservation policy for the future

Treatment of fevers prior to introducing rapid diagnostic tests for malaria in registered drug shops in Uganda.

BACKGROUND: Since drug shops play an important role in treatment of fever, introducing rapid diagnostic tests (RDTs) for malaria at drug shops may have the potential of targeting anti-malarial drugs to those with malaria parasites and improve rational drug use. As part of a cluster randomized trial to examine impact on appropriate treatment of malaria in drug shops in Uganda and adherence to current malaria treatment policy guidelines, a survey was conducted to estimate baseline prevalence of, and factors associated with, appropriate treatment of malaria to enable effective design and implementation of the cluster randomized trial. METHODS: A survey was conducted within 20 geographical clusters of drug shops from May to September 2010 in Mukono district, central Uganda. A cluster was defined as a parish representing a cluster of drug shops. Data was collected using two structured questionnaires: a provider questionnaire to capture data on drug shops (n=65) including provider characteristics, knowledge on treatment of malaria, previous training received, type of drugs stocked, reported drug sales, and record keeping practices; and a patient questionnaire to capture data from febrile patients (n=540) exiting drug shops on presenting symptoms, the consultation process, treatment received, and malaria diagnoses. Malaria diagnosis made by drug shop vendors were confirmed by the study team through microscopy examination of a blood slide to ascertain whether appropriate treatment was received. RESULTS: Among febrile patients seen at drug shops, 35% had a positive RDT result and 27% had a positive blood slide. Many patients (55%) had previously sought care from another drug shop prior to this consultation. Three quarters (73%) of all febrile patients seen at drug shops received an anti-malarial, of whom 39% received an ACT and 33% received quinine. The rest received another non-artemisinin monotherapy. Only one third (32%) of patients with a positive blood slide had received treatment with Coartem® while 34% of those with a negative blood slide had not received an anti-malarial. Overall appropriate treatment was 34 (95% CI: 28 - 40) with substantial between-cluster variation, ranging from 1% to 55%. CONCLUSION: In this setting, the proportion of malaria patients receiving appropriate ACT treatment at drug shops was low. This was due to the practice of presumptive treatment, inadequate training on malaria management and lack of knowledge that Coartem® was the recommended first-line treatment for malaria. There is urgent need for interventions to improve treatment of malaria at these outlets

Rolling contact fatigue performance of HIPed Si3N4 with different surface roughness

Accelerated rolling contact fatigue four-ball tests were performed on hot isostatically pressed (HIPed) silicon nitride/steel contacts under lubricated condition using a PLINT TE92/HS microprocessor controlled rotary tribometer at a maximum compressive stress of 6.58 GPa and at a speed of 10,000 rpm for 135-200 million stress cycles. Rolling track surfaces were examined by optical microscopy, SEM, 3-D surface analysis, atomic force microscopy and interference profilometry. Experimental results show that with an initial roughness value R-a from 0.016 to 0.094 mum, the surfaces became smoother during testing and surface pitting (10-20 mum) occurred. For the surfaces with a roughness value R-a from 0.002 to 0.008 mum, the surfaces became rougher and lubricant oil residues were deposited at the edges of rolling track. Some small and shallow surface pitting 2-3 mum in size was also observed. Some scratch marks left on the surface by the previous lapping process were further extended during testing. R-a and R-q are still most important roughness parameters in relation to rolling contact behaviour. The effects of other surface roughness parameters, such as the shape of the valley. R-sk and R-ku are not obvious in this study

Contamination

Soil contamination occurs when substances are added to soil, resulting in increases in concentrations above background or reference levels. Pollution may follow from contamination when contaminants are present in amounts that are detrimental to soil quality and become harmful to the environment or human health. Contamination can occur via a range of pathways including direct application to land and indirect application from atmospheric deposition. Contamination was identified by SEPA (2001) as a significant threat to soil quality in many parts of Scotland. Towers et al. (2006) identified four principal contamination threats to Scottish soils: acidification; eutrophication; metals; and pesticides. The Scottish Soil Framework (Scottish Government, 2009) set out the potential impact of these threats on the principal soil functions. Severe contamination can lead to “contaminated land” [as defined under Part IIA of the Environmental Protection Act (1990)]. This report does not consider the state and impacts of contaminated land on the wider environment in detail. For further information on contaminated land, see ‘Dealing with Land Contamination in Scotland’ (SEPA, 2009). This chapter considers the causes of soil contamination and their environmental and socio-economic impacts before going on to discuss the status of, and trends in, levels of contaminants in Scotland’s soils

Non-Speaking Autistic Participation in Liturgy and Church Life : (Non-)Speech Acts

Acknowledgements We are grateful to the Carnegie Trust for the Universities in Scotland for funding this research project. “For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising from this submission.”Peer reviewedPostprin

The meaning and practice of stewardship in South Africa

Stewardship offers a means of addressing social-ecological sustainability challenges, from the local to the global level. The concept of stewardship has had various meanings attached to it over time, and the links between the theory and practice of stewardship are not well understood. We sought to characterise the practice of stewardship in South Africa, to better understand the relationship between theory and practice. We found that practitioners' understandings of stewardship coalesce around two core notions: the idea of stewardship as 'responsible use and care' of nature, and stewardship as a 'balancing act' between stewards' use of natural resources for agricultural production and their responsibility to protect and manage the wider ecosystem. Stewardship practice in South Africa is strongly influenced by the biodiversity stewardship tool; however, many practitioners are integrating biodiversity stewardship with other approaches. These emerging social-ecological stewardship initiatives operate at landscape-level and work towards integrated social and ecological stewardship outcomes, by facilitating collaboration among diverse stakeholders. Further research is needed to better understand what is required to support these integrated, collaborative and cross-sectoral initiatives. Policy mechanisms that facilitate integrated place-based stewardship practice can contribute to expanding the practice of biodiversity stewardship in South Africa

Non-financial shareholder activism: A process model for influencing corporate environmental and social performance

Shareholders have become increasingly active in endeavouring to influence companies’ environmental and social practices. In comparison with the mature field of financially motivated shareholder activism, limited enquiries have been carried out on its non-financial counterparts. This paper synthesizes the knowledge base through a review of the academic literature, exploring shareholder activism intended to affect corporate environmental and social performance. Theoretical perspectives appropriate to this phenomenon are critically appraised: in particular, insights from social movement theory, Hirschman's theory of exit, voice and loyalty and stakeholder salience theory, as well as the roles of signalling and symbolic management actions. Data from the literature are organized into a process model of non-financial shareholder influence. Underpinned by the influencing context, this conceptualization centres on three primary shareholder interventions: divestment, dialogue and shareholder proposals. These interventions are enabled through a range of actors and tools: coalitions, non-governmental organizations, codes and indices, the media and regulators. The interaction between interventions and the enabling actors and tools helps to determine managers’ perceptions of shareholder salience. These perceptions subsequently shape the organizational behaviours that affect companies’ symbolic and substantive environmental and social performance. An agenda to direct future research in this burgeoning field is articulated

How shareholder activism influences company non-financial performance.

Shareholders have become increasingly active in endeavouring to influence companies’ non-financial performance, but enquiries into this form of shareholder activism are limited and fragmented. It is as yet unclear what aspects of company non-financial performance are of most interest to shareholders. Researchers have yet to uncover the conditions under which shareholder interventions succeed, or how boards respond beyond simple increases in disclosure. Furthermore, research in emerging markets is almost non-existent. This thesis addresses these gaps in two main ways. First, a systematic literature review provides a synthesis of the state of academic knowledge about shareholder activism that aims to influence corporate environmental and social performance. Theoretical perspectives appropriate to this phenomenon are critically appraised, and data from the literature are organised into a new process model of shareholder influence. An agenda to direct future research in this burgeoning field is articulated. Second, an empirical study investigates non-financial shareholder activism in the context of companies listed on the Johannesburg Stock Exchange, drawing on interviews with a range of participants, as well as media reports and company documentation. An enhanced process model of the phenomenon is proposed that details a broad range of shareholder interventions, and shows how their impact is moderated by several variables. A typology of directors’ actions and concomitant outcomes is detailed, showing the presence of a feedback loop to the factors moderating the process. A set of environmental, social and governance (ESG) issues of interest to contemporary shareholders is presented, showing what shareholders believe constitute company non-financial performance. Insight is provided into contradictions in the concept of ESG, particularly in the conflation of company environmental and social performance and company governance processes. A concluding discussion then explains how this two-pronged approach has enriched the existing knowledge base, implications for practitioners are provided and an enhanced research agenda is offered.PhD in Leadership and Managemen

The Perfect Vulva? Investigating Labiaplasty in South Africa

Labiaplasty, also referred to as labial reduction, is the partial surgical removal of the labia minora in order to shorten the length that is external to the outer lips of the vulva. The conversation about labial length over the past ten years has become an important part of public debates around women’s sexual and gynaecological health. In these debates, a demand for what has become popularised as the ‘Barbie Vagina’ has become part of the conversation. Labiaplasty is a female genital cosmetic surgery designed to make this ‘Barbie vagina’ look possible, in order to achieve vulvas that are ‘neat’ and ‘tucked’. South Africa, with its complex political economy of a small number of very wealthy households and a much poorer majority, has been part of global aesthetic patterns for much of the last century and has experience a growing demand for labiaplasty procedures. To explore labiaplasty in South Africa I conduct an ethnography among plastic surgeons, aesthetic gynaecologists and clinical sexologists to understand how popular labiaplasty has become in South Africa. However, it was clear early on that knowledge about labiaplasty in South Africa was not easily accessible and by pushing my search for this knowledge I discovered firstly: the historical perpetuations of the body beautiful in plastic surgery in South Africa enveloped in ideas of race and beauty, and secondly complicated turf wars among specialisations of medicine fighting for legitimacy to perform labiaplasty.Dissertation (MSocSci (Social Anthropology))--University of Pretoria, 2021.Anthropology and ArchaeologyMSocSci (Social Anthropology)Unrestricte