Free-molecule-flow force and moment coefficients of the aeroassist flight experiment vehicle

Calculated results for the aerodynamic coefficients over the range of + or - 90 deg in both pitch and yaw attitude angles for the Aeroassist Flight Experiment (AFE) vehicle in free molecule flow are presented. The AFE body is described by a large number of small flat plate surface elements whose orientations are established in a wind axes coordinate system through the pitch and yaw attitude angles. Lift force, drag force, and three components of aerodynamic moment about a specified point are computed for each element. The elemental forces and moments are integrated over the entire body, and total force and moment coefficients are computed. The coefficients are calculated for the two limiting gas-surface molecular collision conditions, namely, specular and diffuse, which assume zero and full thermal accommodation of the incoming gas molecules with the surface, respectively. The individual contribution of the shear stress and pressure terms are calculated and also presented

Skyport airframe: design and manufacturing

Many rural areas of developing countries lack the necessary transportation infrastructure to have reliable access to basic needs. This is particularly true for medical supplies. To combat the issue of insufficient access to vaccines in developing areas, the SkyPort project has developed the SkyPort UAV (Unmanned Aerial Vehicle). The SkyPort UAV has the vertical takeoff and landing (VTOL) capabilities of a quadcopter, as well as the efficient, sustained flight of a fixed-wing aircraft. It provides a cheaper, quicker, and safer delivery method than existing alternatives for vaccines in areas that lack a reliable transportation infrastructure. The role of the SkyPort Airframe Design Team was to design and build the primary support structure of the UAV, which will house the payload, controls, and propulsion systems being designed by the other two SkyPort teams. The airframe consists of a lightweight and durable fuselage, wing, tail, and framing subsystems and it is designed to be modular so that parts are easy to replace and require minimal maintenance. Primary materials used in construction were foam, carbon fiber, and aluminum. Testing of the frame yielded a weight of 8.63 kg, minimum foam strength of 1.70 MPa, and a minimum factor of safety of 16 for the structural members of the frame. Although the weight of the airframe is higher than the desired weight, this was necessary in order to satisfy the strength requirements and protect sensitive electrical components during initial flight tests. In the future, this extra weight could be decreased by using less carbon fiber, lower density foam, smaller, lighter material for the structural members, or smaller fasteners

Marketisation in higher education in Africa: new directions for a decolonising continent

The marketisation of higher education is an idea that originated in the west and was promoted to serve specific purposes. Based in a neo-liberal philosophy of free markets and originating in the declarations of Sorbonne 1998 and Bologna 1999 and the World Trade Organisation’s General Agreement on Trades in Services (GATS), 1995 marketisation was conceived as a strategy for encouraging free movement of goods, services and knowledge across the countries of the west, especially those in Europe. This, it was argued, would improve efficiencies and effectiveness, encourage comparability of standards across countries and provide large sections of the population with greater access to services and programmes. The idea sounded appealing and no sooner than it had taken off in Europe, did African countries join the bandwagon. This chapter argues that marketisation in African universities should seek a different moral compass and be based on different sets of assumptions and rationales to those operating in the west. The conceptual field discussed in the first chapter is used to provide critical analysis of the claim that has been made about misdiagnosis and wrong prescriptions. The chapter also argues that, at the moment, Africa cannot afford the free-markets model proposed for Europe but requires a highly regulated market, which responds to and seeks to interrogate issues of poverty, inequality and unemployment, and corruption, which blight the entire continent. The chapter is concluded with a proposal for rethinking the marketing of higher education in Africa

The Optimization of Microraft Production and Use for Cell Identification and Sorting

Microwell arrays containing magnetic microrafts provide an alternative to fluorescence-activated cell sorting (FACS) that allows for the sorting of cells using temporal characteristics and improved viability for adherent cell lines. Making these arrays from thicker layers of polydimethylsiloxane (PDMS) improved the imaging quality by reducing the sagging of the array caused by the weight of cell culture media and did not hinder the effectiveness of releasing the rafts for cell sorting. It was also found that centrifugation of cells in these arrays drastically reduced the time it took for the cells to sediment into the wells at the desired density and did not reduce the viability of the cells.Bachelor of Scienc

Investigating market orientation and positioning in star-rated hotels in Ghana

Purpose: Market orientation and positioning have been widely recognized as organizational metrics linked to hotel performance. This study offered empirical evidence on the relationship among market orientation, positioning, and hotel performance in Ghana’s (luxury) hotel sector. It also reports on the joint effect of market orientation and positioning on hotel performance in the same sector. Design/methodology/approach: Three hypotheses were investigated on the relationship between market orientation and hotel performance; positioning and hotel performance; and the joint effect of market orientation and positioning on hotel performance. A survey of star rated (luxury) hotels in the capital city of Ghana was used. One hundred and five (105) responses were used in the analysis. Descriptive statistics, exploratory factor analysis and hierarchical regression were used to test the three (3) hypotheses. Findings: All hypotheses were accepted. Market orientation and positioning jointly affect hotel performance, and the study provides hotel managers with suggestions on to enhance their performance via market orientation and positioning. Research limitations/implications: Management perspectives on market orientation, positioning and hotel performance were sought to the exclusion of customers. Future studies may consider using customer perspectives as well. Practical implications: Hotels should consider adopting market oriented positioning strategies to improve on their performance. Originality/value: This study is one of the few attempts to systematically investigating the intertwined concepts of market orientation, positioning and performance in a developing economy hospitality context

Examining Consumer Mobile Money Usage Behaviour in Ghana

This study develops a theoretical model to examine the effects of agent credibility and service quality on customer empowerment and the consequences of such empowerment in mobile money (MM) usage in Ghana. In total, 595 valid responses were collected using a pre-tested onsite-survey instrument. The research findings suggest that a higher level of MM agent credibility increases customer empowerment, which in turn positively affects the continuous usage of MM services. A significant association between MM agent service quality and customer empowerment was also noted. The study concludes with a discussion of study implications, limitations, and future research directions