New techniques for experimental generation of two-dimensional blade-vortex interaction at low Reynolds numbers

An experimental investigation of two dimensional blade vortex interaction was held at NASA Langley Research Center. The first phase was a flow visualization study to document the approach process of a two dimensional vortex as it encountered a loaded blade model. To accomplish the flow visualization study, a method for generating two dimensional vortex filaments was required. The numerical study used to define a new vortex generation process and the use of this process in the flow visualization study were documented. Additionally, photographic techniques and data analysis methods used in the flow visualization study are examined

Coloured mulch as a weed control technology and yield booster for summer savory

An investigation into the effect of coloured mulch technology as a technique to control weeds when growing the essential oil plant, summer savory (Satureja hortensis) was made. As well as weed control, the effects on the production of crop biomass and essential oil content and quality were also considered. The mulch treatments produced significantly more biomass than either of the control treatments (which used no mulch either with or without herbicide). The white mulch treatment produced the greatest biomass, closely followed by the red mulch treatment. The blue mulch treatment was third in ranking, although not significantly greater than the black mulch. Estimates of the quantity of essential oil produced by each treatment followed a similar trend to that shown by biomass production

Renormalization of the Lattice Heavy Quark Classical Velocity

In the lattice formulation of the Heavy Quark Effective Theory (LHQET), the classical velocity is renormalized. The origin of this renormalization is the reduction of Lorentz (or O(4)) invariance to (hyper)cubic invariance. The renormalization is finite and depends on the form of the decretization of the reduced heavy quark Dirac equation. For the Forward Time - Centered Space discretization, the renormalization is computed both perturbatively, to one loop, and non-perturbatively using an ensemble of lattices provided by the Fermilab lattice collaboration. The estimates of the leading (linear) shift agree, and indicate that for small classical velocities, the renormalized velocity is reduced by about 25-30% relative to its bare (input) value.Comment: 4 pages in uuencoded compressed postscript (using uufiles); Talk given at Lattice '95 (Melbourne

Is U3Ni3Sn4 best described as near a quantum critical point?

Although most known non-Fermi liquid (NFL) materials are structurally or chemically disordered, the role of this disorder remains unclear. In particular, very few systems have been discovered that may be stoichiometric and well ordered. To test whether U3Ni3Sn4 belongs in this latter class, we present measurements of the x-ray absorption fine structure (XAFS) of polycrystalline and single-crystal U3Ni3Sn4 samples that are consistent with no measurable local structural disorder. We also present temperature-dependent specific heat data in applied magnetic fields as high as 8 T that show features that are inconsistent with the antiferromagnetic Griffiths' phase model, but do support the conclusion that a Fermi liquid/NFL crossover temperature increases with applied field. These results are inconsistent with theoretical explanations that require strong disorder effects, but do support the view that U3Ni3Sn4 is a stoichiometric, ordered material that exhibits NFL behavior, and is best described as being near an antiferromagnetic quantum critical point.Comment: 9 pages, 8 figures, in press with PR

Beyond sustainable buildings: eco-efficiency to eco-effectiveness through cradle-to-cradle design

This study investigates the cradle to cradle philosophy, which is a paradigm changing innovative platform for achieving positive ecological impacts in the built environment. With focus on business sites, a preliminary survey is conducted to interrogate tenant stakeholders’ preferences towards cradle to cradle attributes. Training, employment and use of local skills (social diversity)as well as realisation of highly flexible and easily adaptable spaces (conceptual diversity) were revealed as the most important attributes whilst integration of biodiversity was of least importance. This suggests therefore that business needs drive their preferences and as such must be reflected in C2C implementation strategies

Cradle to cradle implementation in business sites and the perspectives of tenant stakeholders

This study investigates the cradle to cradle philosophy, which is a paradigm changing innovative platform for achieving positive ecological impacts in the built environment. With focus on business sites, a preliminary survey is conducted to interrogate tenant stakeholders' preferences towards cradle to cradle attributes. Training, employment and use of local skills (social diversity) as well as realisation of highly flexible and easily adaptable spaces (conceptual diversity) were revealed as the most important attributes whilst integration of biodiversity was of least importance. This suggests therefore that business needs drive their preferences and as such must be reflected in C2C implementation strategies

Quantifying structural damage from self-irradiation in a plutonium superconductor

The 18.5 K superconductor PuCoGa5 has many unusual properties, including those due to damage induced by self-irradiation. The superconducting transition temperature decreases sharply with time, suggesting a radiation-induced Frenkel defect concentration much larger than predicted by current radiation damage theories. Extended x-ray absorption fine-structure measurements demonstrate that while the local crystal structure in fresh material is well ordered, aged material is disordered much more strongly than expected from simple defects, consistent with strong disorder throughout the damage cascade region. These data highlight the potential impact of local lattice distortions relative to defects on the properties of irradiated materials and underscore the need for more atomic-resolution structural comparisons between radiation damage experiments and theory.Comment: 7 pages, 5 figures, to be published in PR

Embodied Resilience: Supervising/Mentoring during a Time of COVID-19, Black Lives Matter, and Climate Change

The authors take on the task of addressing three of the most significant issues in our society today and how one functions as a mentor and supervisor

Gene Therapy in Cellular Immunodeficiencies

The treatment of cellular primary immunodeficiencies has benefitted from significant advances in the field of allogeneic stem cell transplantation (alloHSCT). However, while this therapy is curative for many PIDs, the procedure requires a suitably matched donor and carries significant risks of morbidity and mortality from complications such as graft-versus-host disease (GVHD). Autologous gene therapy (GT) approaches using stem cells isolated from patients and modified ex vivo using viral vectors or gene editing techniques have the potential to offer curative therapy for PID without the immunological complications of alloHSCT. GT for PID has been developed over the last 30 years, and while several setbacks have been encountered along the way, there is now a licensed GT product for ADA-SCID, and promising results from phase I/II clinical trials have demonstrated that GT may offer clinical efficacy comparable to alloHSCT in several other PIDs. Developments in the field are broadening the application of GT, and we expect that this therapeutic modality may become standard of care for the management of several PIDs in the near future. This chapter explores the development of GT over the last 30 years and outlines its role in the management of cellular primary immunodeficiencies

Probing 5f-state configurations in URu2Si2 with U L3-edge resonant x-ray emission spectroscopy

Resonant x-ray emission spectroscopy (RXES) was employed at the U L3 absorption edge and the La1 emission line to explore the 5f occupancy, nf, and the degree of 5f orbital delocalization in the hidden order compound URu2Si2. By comparing to suitable reference materials such as UF4, UCd11, and alpha-U, we conclude that the 5f orbital in URu2Si2 is at least partially delocalized with nf = 2.87 +/- 0.08, and does not change with temperature down to 10 K within the estimated error. These results place further constraints on theoretical explanations of the hidden order, especially those requiring a localized f2 ground state.Comment: 11 pages,7 figure