Impact of armature rewinding on induction motor efficiency in South Africa

Includes bibliographical references (p. 162-168).The aim of this thesis is to evaluate the impact of armature rewinding on the efficiency of Low Voltage (LV) industrial squirrel cage induction motors in South Africa. The efficiency of an electric motor is a measure of the effectiveness of the motor to convert electrical power at its terminals to mechanical power at its shaft. Although the definition is seemingly simple and straightforward, the determination of the efficiency of an induction motor is a much-debated topic. Motor manufacturers provide efficiency data obtained through measurement and calculation according to a variety of international standards. Several international standards exist, with each outlining different methods and procedures for the determination of induction motor efficiency. Most notable among the disparities is the treatment of stray losses. For example, the Japanese standard JEC-37 assumes stray losses to be negligible, others such as SANS 34-2 and ASINZ 1359.5 use a fixed value, while IEEE 112, CSA 390 and lEC 34-2 prefer to make actual measurements. A number of these standards were initially considered. However, after preliminary laboratory-tests were performed, it was observed that the IEEE 112 method B (2004) and IEC 60034-2 segregation method (2007) appeared to be the most consistent and repeatable. The two standards were therefore preferred and subsequently chosen for this project. The South African standard, SANS 34-2, is available but its methods of determining efficiency have been found to be unsupported due to its reference to the IEC 60034-2 (1984) which has been abandoned and replaced. The SANS 34-2 was therefore not used in the testing

Personality and attitude changes associated with long-term imprisonment

Very little is known about the psychological effects of imprisonment in general, and long-term imprisonment in particular. Most of our knowledge about imprisonment and its effects is derived from American sociological research, such as the classic study by Clemmer (1940), Psychologists seem to have avoided the problem and what data exists bears on the topic only tangentially. This study is an attempt to begin the process of bringing a particularly psychological point of view to bear on the issue. The study is essentially a two-fold psychometric examination of the question of the effects of long-term imprisonment on personality (as measured by the Sysenck Personality Inventory, the Gough Femininity Scale, the Sixteen Personality Factor Questionnaire) and attitudes (as measured by the Semantic Differential). First, a cross-sectional analysis is outlined which yields data on the differences between groups of men in prison who have served differing mean lengths of total imprisonment during their careers. Second, a longitudinal analysis is presented which illustrates the changes which took place over the relatively short test-retest interval of 19 months, A factor- analytical study of the cross-sectional data and more detailed longitudinal analyoes of identifiable psychometric groups are also presented. Finally, an attempt is made to integrate the results into a coherent picture and suggestions are proffered which, it is hoped, may be of use both to future researchers and to the custodians of long-term prisoners

Performance Evaluation of Additively Manufactured Carbon/PEEK Composites

Carbon/PEEK composites have a broad range of applications due to their combinations of superior creep properties and excellent strength to weight ratios. Like all fiber-based composites they are limited geometrically by their required manufacturing processes. Additively manufactured (AM) materials overcome this issue and can be formed into incredibly complex shapes. By combining these two fields, a material limited in application by geometry can have its shortcomings supported with AM processes. AM carbon/PEEK composites have already been created but this relatively new material still needs property characterization. Therefore, the objective of this work will be to evaluate the structural performance of additively manufactured carbon/PEEK composites, specifically Young’s modulus. The resulting data can be compared to standard carbon/PEEK composites to better understand the change in material property as a result of a different manufacturing process

Early identification of high-risk individuals for monoclonal antibody therapy and prophylaxis is feasible by SARS-CoV-2 anti-spike antibody specific lateral flow assay.

Monoclonal antibody therapy has been approved for prophylaxis and treatment of severe COVID-19 infection. Greatest benefit appears limited to those yet to mount an effective immune response from natural infection or vaccination, but concern exists around ability to make timely assessment of immune status of community-based patients where laboratory-based serodiagnostics predominate. Participants were invited to undergo paired laboratory-based (Abbott Architect SARS-CoV-2 IgG Quant II chemiluminescent microparticle immunoassay) and lateral flow assays (LFA; a split SARS-CoV-2 IgM/IgG and total antibody test) able to detect SARS-CoV-2 anti-spike antibodies. LFA band strength was compared with CMIA titer by log-linear regression. Two hundred individuals (median age 43.5 years, IQR 30-59; 60.5% female) underwent testing, with a further 100 control sera tested. Both LFA band strengths correlated strongly with CMIA antibody titers (P < 0.001). LFAs have the potential to assist in early identification of seronegative patients who may demonstrate the greatest benefit from monoclonal antibody treatment

Al Qaeda at the bar: coordinating ideologues and mercenaries in terrorist organizations

Most terrorist groups have limited lifespans. A number of scholars and casual observers have noted that terrorist organizations often are comprised of two types of participants: ideologues or "true believers" dedicated to the group's cause, and mercenaries, who are adept at raising money through illegal means. The latter are interested primarily in their personal gains and have relatively little ideological commitment. Terrorist groups need both participants in order to function effectively. The purpose of the study is to understand the impact of communication on the compositions of terrorist groups. Three experimental treatments consider a coordination problem, and focus on the behavior of the mercenaries. Participants choose whether or not to participate in a terrorist attack. Payoffs are U-shaped in the number of participants, and increase with the number of successful attacks. The treatments allow communication between a leader and frontline fighters ("leader" treatment) or among the frontline fighters themselves ("communication" treatment). In the first treatment, a group leader can post messages to the members, which has a 19 % coordination success rate. For the communication treatment, all participants can post messages anonymously to each other, which yields a 27 % coordination success rate. By contrast, the baseline ("no communication" treatment) shows a success rate of 11 %. We conclude from our experimental evidence that disrupting communications among the frontline fighters is more effective in terminating terrorist organizations

Clinical features and management of individuals admitted to hospital with monkeypox and associated complications across the UK: a retrospective cohort study.

BACKGROUND: The scale of the 2022 global mpox (formerly known as monkeypox) outbreak has been unprecedented. In less than 6 months, non-endemic countries have reported more than 67 000 cases of a disease that had previously been rare outside of Africa. Mortality has been reported as rare but hospital admission has been relatively common. We aimed to describe the clinical and laboratory characteristics and outcomes of individuals admitted to hospital with mpox and associated complications, including tecovirimat recipients. METHODS: In this cohort study, we undertook retrospective review of electronic clinical records and pathology data for all individuals admitted between May 6, and Aug 3, 2022, to 16 hospitals from the Specialist and High Consequence Infectious Diseases Network for Monkeypox. The hospitals were located in ten cities in England and Northern Ireland. Inclusion criteria were clinical signs consistent with mpox and MPXV DNA detected from at least one clinical sample by PCR testing. Patients admitted solely for isolation purposes were excluded from the study. Key outcomes included admission indication, complications (including pain, secondary infection, and mortality) and use of antibiotic and anti-viral treatments. Routine biochemistry, haematology, microbiology, and virology data were also collected. Outcomes were assessed in all patients with available data. FINDINGS: 156 individuals were admitted to hospital with complicated mpox during the study period. 153 (98%) were male and three (2%) were female, with a median age of 35 years (IQR 30-44). Gender data were collected from electronic patient records, which encompassed full formal review of clincian notes. The prespecified options for data collection for gender were male, female, trans, non-binary, or unknown. 105 (71%) of 148 participants with available ethnicity data were of White ethnicity and 47 (30%) of 155 were living with HIV with a median CD4 count of 510 cells per mm3 (IQR 349-828). Rectal or perianal pain (including proctitis) was the most common indication for hospital admission (44 [28%] of 156). Severe pain was reported in 89 (57%) of 156, and secondary bacterial infection in 82 (58%) of 142 individuals with available data. Median admission duration was 5 days (IQR 2-9). Ten individuals required surgery and two cases of encephalitis were reported. 38 (24%) of the 156 individuals received tecovirimat with early cessation in four cases (two owing to hepatic transaminitis, one to rapid treatment response, and one to patient choice). No deaths occurred during the study period. INTERPRETATION: Although life-threatening mpox appears rare in hospitalised populations during the current outbreak, severe mpox and associated complications can occur in immunocompetent individuals. Analgesia and management of superimposed bacterial infection are priorities for patients admitted to hospital. FUNDING: None