Ramjet compression system for a hypersonic air transportation vehicle combined cycle engine

This report assesses the performance characteristics of a ramjet compression system in the application of a hypersonic vehicle. The vehicle is required to be self-powered and perform a complete flight profile using a combination of turbojet, ramjet and scramjet propulsion systems. The ramjet has been designed to operate between Mach 2.5 to Mach 5 conditions, allowing for start-up of the scramjet engine. Multiple designs, including varying ramp configurations and turbo-ramjet combinations, were investigated to evaluate their merits and limitations. Challenges arose with attempting to maintain sufficient pressure recoveries and favourable flow characteristics into the ramjet combustor. The results provide an engine inlet design capable of propelling the vehicle between the turbojet and scramjet phase of flight, allowing for the completion of its mission profile. Compromises in the design, however, had to be made in order to allow for optimisation of other propulsion systems including the scramjet nozzle and aerodynamics of the vehicle; it was concluded that these compromises were justified as the vehicle uses the ramjet engine for a minority of the flight profile as it transitions between low supersonic to hypersonic conditions

In vitro evaluation of cytotoxic effects of methanolic leaf extracts of Annona muricata on oral squamous cell carcinoma-15 cell lines and its effect on expression of Bcl 2-associated X protein, B-cell C/lymphoma 2 and p53 genes

Background: Due to their wide spectrum of phytochemical components and lack of side effects, the use of plants for the prevention and treatment of cancer has recently attracted increased attention. One among them is Annona muricata, commonly called soursop. According to recent investigations, several types of cancer have been successfully treated using this plant's extracts. However, studies on oral squamous cell carcinoma (SCC) are very limited. Aim: In the present study, we aimed to investigate the cytotoxic potential of leaf extract of A. muricata (LEAM) against oral tongue SCC-15 cell lines, using in vitro assays. Materials and Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-dipenyltetrazolium bromide assay was performed to assess cytotoxic activity, and the apoptotic effect was determined using gene expression analyses of Bcl 2-associated X protein (Bax), B-cell C/lymphoma 2 (Bcl-2), and tumor-suppressor phosphoprotein (p53). Results: Significant cytotoxicity (P ≤ 0.05) with a minimum inhibitory concentration value of 40 μg/ml was observed with the LEAM on SCC-15 cell lines. A highly significant decrease was observed in Bcl-2 gene expression (P < 0.05), whereas p53 and BAX genes revealed a highly significant increase (P < 0.05) when SCC-15 cell lines were treated with LEAM in the study group compared to the control. Conclusion: These results show that LEAM has the potential for development as a therapeutic agent for cytotoxicity, particularly on oral SCC cells, following further investigation

Day jobs/nightwork: academic staff studying towards higher degrees

Universities of Technology (UTs) offer career-focused education in a wide variety of disciplines and fields. Traditionally, UTs recruited academic staff with relevant workplace experience, rather than academic qualifications. The result of this strategy was, while many lecturers possessed professional qualifications in their field, they did not have Masters or Doctoral degrees. Much has changed over the past years. For example, most UTs now have requirements that, in order to be appointed as a lecturer, new staff should already be in possession of a Masters degree (although in several programmes this is not a viable requirement). Existing members of staff (appointed before the Masters degree was required) are encouraged to study towards higher degrees. The attainment of a Masters (and preferably a Doctoral) degree, followed by research outputs, are important considerations for promotion and notch increases. Trying to study while working full-time has many challenges, and busy lecturers undertaking this journey need various forms of support. They need teaching relief, research assistance and financial support for their research activities as well as access to resources and equipment and the support of experienced and knowledgeable supervisors and mentors. Academic staff members’ perceptions and reflections on the experience of studying towards Masters and Doctoral degrees were canvassed through an institution-wide survey. In this article, we discuss the findings of the survey, and recommend ways in which institutions could support academic staff who are engaged in studying towards higher degrees