Reaction of metallic iron and copper sulphate in the flotation of sphalerite

Copper sulphate is a common flotation reagent for blende ores. Metallic iron is also present in the mill circuit and a reaction between the iron and the salt would be in accord with well known chemistry. The abundance of metallic iron in a flotation feed may be noted by the examination of any feed. It originates, first of all, in the mine, then the coarse crushing machines contribute their share, and finally the fine grinding medium is a large contributor. If the grinding is with cast iron balls in amount of metallics is greater than when steel is used. In the end much more metallic iron is present than would be indicated by noting the ball consumption. An estimate that the total amount of metallics is twice that supplied by the balls and liners might not be far amiss. It is well known that copper sulphate plates cut on iron in an acid solution, but since flotation is common in solutions where acid has not been added this reaction has not been given due thought --Introduction, page 1

Alcohol and disorder in precolonial Africa

African Studies Center Working Paper No. 126Alcohol has for centuries played a prominent role in the social and religious life of African societies south of the Sahara. As early as the eleventh century AD., Al-Bakri described offerings of alcoholic drinks in royal funeral rites in the kingdom of Ghana. Indeed, from other scattered references it is clear that alcohol pervaded the continent, and that the consumption, exchange, or offering of alcoholic beverages was often a central element in the ritual life of communities. Before the latter part of the nineteenth century, distillation was largely unknown and imported distilled drinks were confined to a few areas; but virtually every community produced one or more types of fermented drinks from grain, fruits, honey, palm sap or sugar cane. Consumption of these beers commonly accompanied celebrations of season and passage, legal deliberations, and meetings of elders; gifts of beer were made to prospective in-laws, to patrons and rulers, and to honored guests; and the pouring of libations mediated relations with gods and ancestors. Yet despite an upsurge of interest in the social history of alcohol in Europe and America, Africanist scholars have paid the topic little attention. Moreover, the work that has been done is concerned with the relatively recent past and has focused very largely on attempts by the state - notably in South Africa - to regulate production and consumption

Design of an underwater vertical glider for subsea equipment delivery

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 113-115).Delivery of subsea equipment and sensors is generally accomplished with unguided sinking platforms or powered autonomous underwater vehicles (AUVs). An alternative would be to augment existing platforms with navigation and guidance capability, enabling them to actively guide themselves to their destination, with minimal added complexity and power consumption. This defines a new class of AUV having 110 propulsion, which we call the Vertical Glider. This thesis investigates the challenges posed by this deployment concept, and describes in detail a prototype vertical glider that was built for initial tests. We explore through computer simulation the specific roles of various operating parameters, such as control gain, measurement noise, and process noise, on the overall vehicle performance. The prototype vehicle has been successfully pool-tested, and serves as a baseline platform for open water operations and multi-vehicle deployments.by Charles Kirby Ambler.S.M

Exploring patients’ experiences of analgesia after major lower limb amputation: A qualitative study

OBJECTIVES: To explore patient experiences, understanding and perceptions of analgesia following major lower limb amputation. DESIGN: Qualitative interview study, conducted as part of a randomised controlled feasibility trial. SETTING: Participants were recruited from two general hospitals in South Wales. PARTICIPANTS: Interview participants were patients enrolled in PLACEMENT (Perineural Local Anaesthetic Catheter aftEr Major lowEr limb amputatioN Trial): a randomised controlled feasibility trial comparing the use of perineural catheter (PNC) versus standard care for postoperative pain relief following major lower limb amputation. PLACEMENT participants who completed 5-day postoperative follow-up, were able and willing to participate in a face-to-face interview, and had consented to be contacted, were eligible to take part in the qualitative study. A total of 20 interviews were conducted with 14 participants: 10 male and 4 female. METHODS: Semi-structured, face-to-face interviews were conducted with participants over two time points: (1) up to 1 month and (2) at least 6 months following amputation. Interviews were audio-recorded, transcribed verbatim and analysed using a framework approach. RESULTS: Interviews revealed unanticipated benefits of PNC usage for postoperative pain relief. Participants valued the localised and continuous nature of this mode of analgesia in comparison to opioids. Concerns about opioid dependence and side effects of pain relief medication were raised by participants in both treatment groups, with some reporting trying to limit their intake of analgesics. CONCLUSIONS: Findings suggest routine placement of a PNC following major lower limb amputation could reduce postoperative pain, particularly for patient groups at risk of postoperative delirium. This method of analgesic delivery also has the potential to reduce preoperative anxiety, alleviate the burden of pain management and minimise opioid use. Future research could further examine the comparison between patient-controlled analgesia and continuous analgesia in relation to patient anxiety and satisfaction with pain management. TRIAL REGISTRATION NUMBER: ISRCTN: 85710690; EudraCT: 2016-003544-37

Does a small central Nd:YAG posterior capsulotomy improve peripheral fundal visualisation for the Vitreoretinal surgeon?

BACKGROUND: To evaluate the effect of Nd:YAG capsulotomy for posterior capsular opacification (PCO) on visualisation of the peripheral fundus with scleral indentation. METHODS: Patients undergoing Nd:YAG capsulotomy for PCO were examined pre- and four weeks post- Nd:YAG capsulotomy. In order to give a quantitative measure of visualisation of the peripheral retina, a novel scalar measurement was developed. Changes in the degree of visualisation following Nd:YAG capsulotomy were calculated. RESULTS: There was a significant improvement in fundal visualisation of the retinal periphery with scleral indentation following Nd:YAG capsulotomy (p = 0.001). CONCLUSION: Peripheral fundal visualisation with scleral indentation improves following a small central Nd:YAG capsulotomy. This finding is important in relation to the detection of peripheral pseudophakic retinal breaks, particularly in those patients deemed at high risk following Nd:YAG capsulotomy

Rheumatology clinicians’ experiences of brief training and implementation of skills to support patient self-management

BACKGROUND: Self-management of arthritis requires informed, activated patients to manage its physical and psychosocial consequences. Patient activation and self-management can be enhanced through the use of cognitive-behavioural approaches, which have a strong evidence base and provide insight into the variation in outcome of patients with ostensibly the same degree of disease activity. However, training for rheumatology health professionals in theory and skills underpinning the facilitation of self-management is not widely available. To develop such training, this study explored rheumatology clinicians’ experiences of a variety of brief skills training courses to understand which aspects were helpful or unhelpful, and to identify the barriers and facilitators of applying the skills in clinical practice. METHODS: 16 clinicians who had previously attended communication and self-management skills training participated in semi-structured interviews: 3 physicians, 3 physiotherapists, 4 nurses, 6 occupational therapists. Transcripts were analysed (ED) using a hybrid inductive and deductive thematic approach, with a subset independently analysed (SH, RG-H, RJ). RESULTS: 3 overarching themes captured views about training undertaken and subsequent use of approaches to facilitate self-management. In ‘putting theory into practice’, clinicians felt that generic training was not as relevant as rheumatology-specific training. They wanted a balance between theory and skills practice, and identified the importance of access to ongoing support. In ‘challenging professional identity’, models of care and working cultures influenced learning and implementation. Training often challenged a tendency to problem-solve on behalf of patients and broadened clinicians’ remit from a primary focus on physical symptoms to the mind and body interaction. In ‘enhanced practice’, clinicians viewed consultations as enhanced after training. Focus had shifted from clinicians’ agendas to those of patients, and clinicians reported eliciting patients’ priorities and the use of theoretically-driven strategies such as goal-setting. CONCLUSIONS: To varying extents, clinicians were able to learn and implement new approaches to support patient self-management after brief training. They believed that cognitive behavioural and communication skills to facilitate self-management enhanced their practice. To optimise self-management support in routine care brief, skills-based, rheumatology-specific training needs to be developed, alongside ongoing clinical supervision. Further research should examine patients’ perspectives of care based on these approaches