A wind tunnel investigation into the effects of roof curvature on the aerodynamic drag experienced by a light goods vehicle

Roof curvature is used to increase ground vehicle camber and enhance rear-body boat-tailing to reduce aerodynamic drag. Little aerodynamic data is published for light goods vehicles (LGVs) which account for a significant proportion of annual UK licensed vehicle miles. This paper details scale wind tunnel measurements at Re = 1.6 × 106 of a generic LGV utilising interchangeable roof panels to investigate the effects of curved roof profile on aerodynamic drag at simulated crosswinds between -6° and 16°. Optimum magnitudes of roof profile depth and axial location are suggested and the limited dataset indicates that increasing roof curvature is effective in reducing drag over a large yaw range, compared to a flat roof profile. This is primarily due to increased base pressure, possibly from enhanced mixing of longitudinal vortices shed from the rear-body upper side edges and increased turbulent mixing in the near-wake due to the increased effective boat-tail angle

Investigation of the aerodynamic characteristics of a lifting body in ground proximity

The use of cambered hull shapes in the next generation of lighter-than-air vehicles to enhance aerodynamic performance, together with optimized take-off manoeuvre profiles, will require a more detailed understanding of ground proximity effects for such aircraft. A series of sub-scale wind tunnel tests at Re = 1.4 x 106 on a 6:1 prolate spheroid are used to identify potential changes in aerodynamic lift, drag and pitching moment coefficients that are likely to be experienced on the vehicle hull in isolation when in close ground proximity. The experimental data is supported by a preliminary assessment of surface pressure changes using a high order panel method (PANAIR) and RANS CFD simulations to assess the flow structure. The effect of ground proximity, most evident when non-dimensional ground clearance (h/c) < 0.3, is to reduce lift coefficient, increase drag coefficient and increase the body pitching moment coefficient

Mesenchymal stem cells to augment therapeutic angiogenesis in hind-limb ischemia models: how important is their source?

Murine models of hind-limb ischemia are frequently used to assess interventions aimed at improving therapeutic angiogenesis in critical limb ischemia. Much of the current focus of angiogenesis lies with mesenchymal stem cells (MSCs). Important considerations when using these models include the strain of mouse, because some strains recover from ischemia more rapidly than others, and the MSC source. MSCs derived from certain strains generate increased levels of growth factors such as vascular endothelial growth factor. This may significantly affect the limb?s ability to generate collateral vessels

Adoption of innovative e-learning support for teaching: A multiple case study at the University of Waikato

In response to recent social, economic, and pedagogical challenges to tertiary-level teaching and learning, universities are increasingly investigating and adopting elearning as a way to engage and motivate students. This paper reports on the first year of a two-year (2009-2010) qualitative multiple case study research project in New Zealand. Using perspectives from activity theory and the scholarship of teaching, the research has the overall goal of documenting, developing, and disseminating effective and innovative practice in which e-learning plays an important role in tertiary teaching. A “snapshot” of each of the four 2009 cases and focused findings within and across cases are provided. This is followed by an overall discussion of the context, “within” and “across” case themes, and implications of the research

Proliferation tracing with single-cell mass cytometry optimizes generation of stem cell memory-like T cells.

Selective differentiation of naive T cells into multipotent T cells is of great interest clinically for the generation of cell-based cancer immunotherapies. Cellular differentiation depends crucially on division state and time. Here we adapt a dye dilution assay for tracking cell proliferative history through mass cytometry and uncouple division, time and regulatory protein expression in single naive human T cells during their activation and expansion in a complex ex vivo milieu. Using 23 markers, we defined groups of proteins controlled predominantly by division state or time and found that undivided cells account for the majority of phenotypic diversity. We next built a map of cell state changes during naive T-cell expansion. By examining cell signaling on this map, we rationally selected ibrutinib, a BTK and ITK inhibitor, and administered it before T cell activation to direct differentiation toward a T stem cell memory (TSCM)-like phenotype. This method for tracing cell fate across division states and time can be broadly applied for directing cellular differentiation

Topological Hysteresis in the Intermediate State of Type-I Superconductors

Magneto-optical imaging of thick stress-free lead samples reveals two distinct topologies of the intermediate state. Flux tubes are formed upon magnetic field penetration (closed topology) and laminar patterns appear upon flux exit (open topology). Two-dimensional distributions of shielding currents were obtained by applying an efficient inversion scheme. Quantitative analysis of the magnetic induction distribution and correlation with magnetization measurements indicate that observed topological differences between the two phases are responsible for experimentally observable magnetic hysteresis.Comment: 4 pages, RevTex

Biomolecular mechanisms of staphylococcal biofilm formation

The multitude of biomolecular and regulatory factors involved in staphylococcal adhesion and biofilm formation owe much to their ability to colonize surfaces, allowing the biofilm form to become the preferential bacterial phenotype. Judging by total number, biomass and variety of environments colonized, bacteria can be categorized as the most successful lifeform on earth. This is due to the ability of bacteria and other microorganisms to respond phenotypically via biomolecular processes to the stresses of their surrounding environment. This review focuses on the specific pathways involved in the adhesion of the Gram-positive bacteria Staphylococcus epidermidis and Staphylococcus aureus with reference to the role of specific cell surface adhesins, the ica operon, accumulation-associated proteins and quorum-sensing systems and their significance in medical device-related infection