Shearing-Stress Measurements by use of a Heated Element

The rate of local heat transfer from a solid surface to a moving fluid is related to the local skin frinction. Measurements of the heat transmission from small elements embedded in the surface of a solid can thus be used to botain local skin-friction coefficients. This method was applied by Fage and Falkner for laminar boundary layers and by Ludwieg for turbulent boundary layers. The present report discussed the possible range of application of such an instrument in low- and high-speed flow and presents experimental data to show that a very simple instrument can be used to obtain laminar and turbulent skin-friction coefficients with a single calibration. The instrument consists of an ordinary hot-wire cemented into a groove in the surface. The heat loss from the wire is proportional to the cube root of the wall shearing stress, and the constant of proportionality may be found by one calibration, for example, in laminar flow

Local Volume Effects in the Generalized Pseudopotential Theory

The generalized pseudopotential theory (GPT) is a powerful method for deriving real-space transferable interatomic potentials. Using a coarse-grained electronic structure, one can explicitly calculate the pair ion-ion and multi-ion interactions in simple and transition metals. Whilst successful in determining bulk properties, in central force metals the GPT fails to describe crystal defects for which there is a significant local volume change. A previous paper [PhysRevLett.66.3036 (1991)] found that by allowing the GPT total energy to depend upon some spatially-averaged local electron density, the energetics of vacancies and surfaces could be calculated within experimental ranges. In this paper, we develop the formalism further by explicitly calculating the forces and stress tensor associated with this total energy. We call this scheme the adaptive GPT (aGPT) and it is capable of both molecular dynamics and molecular statics. We apply the aGPT to vacancy formation and divacancy binding in hcp Mg and also calculate the local electron density corrections to the bulk elastic constants and phonon dispersion for which there is refinement over the baseline GPT treatment.Comment: 11 pages, 6 figure

Boundary regularity of conformally compact Einstein metrics

We show that C^2 conformally compact Riemannian Einstein metrics have conformal compactifications that are smooth up to the boundary in dimension 3 and all even dimensions, and polyhomogeneous in odd dimensions greater than 3.Comment: Latex2e, 25 pages. This is the final version accepted for publication in the Journal of Differential Geometr

Where do uncertainties reside within environmental risk assessments? Expert opinion on uncertainty distributions for pesticide risks to surface water organisms

A reliable characterisation of uncertainties can aid uncertainty identification during environmental risk assessments (ERAs). However, typologies can be implemented inconsistently, causing uncertainties to go unidentified. We present an approach based on nine structured elicitations, in which subject-matter experts, for pesticide risks to surface water organisms, validate and assess three dimensions of uncertainty: its level (the severity of uncertainty, ranging from determinism to ignorance); nature (whether the uncertainty is epistemic or aleatory); and location (the data source or area in which the uncertainty arises). Risk characterisation contains the highest median levels of uncertainty, associated with estimating, aggregating and evaluating the magnitude of risks. Regarding the locations in which uncertainty is manifest, data uncertainty is dominant in problem formulation, exposure assessment and effects assessment. The comprehensive description of uncertainty described will enable risk analysts to prioritise the required phases, groups of tasks, or individual tasks within a risk analysis according to the highest levels of uncertainty, the potential for uncertainty to be reduced or quantified, or the types of location-based uncertainty, thus aiding uncertainty prioritisation during environmental risk assessments. In turn, it is expected to inform investment in uncertainty reduction or targeted risk management action

Polypharmacy Practice Inquiry Project

“The impending crisis, which has been foreseen for decades, is now upon us.The nation needs to act now to prepare the health care workforce to meet the care needs of older adults.” Institute of Medicine. Given the rising tide of people over the age of 65, taking multiple medications or polypharmacy is a becoming more prevalent in older adults. Unfortunately, there are many negative consequences associated with polypharmacy. Specifically, this burden has been associated with greater health care costs and an increased risk of adverse drug events, drug-interactions, medication non-adherence, reduced functional capacity and multiple geriatric syndromes including cognitive impairment. Cognitive impairment, seen with both delirium and dementia, has been associated with polypharmacy. Current medical practice guidelines often require multiple medications to treat each chronic disease state for optimal clinical benefit. Cognitive impairment can put a patient at risk for either under- or overtreatment due to their numerous chronic illnesses requiring treatment. In Primary Care, the burden of polypharmacy can be daunting, especially when patient visit times are short and there are other issues to be addressed. There is a lack of an evidence-based, step-by-step protocol to address polypharmacy in Primary Care that can take the healthcare provider and patient through the medication list together, efficiently. If there was such an instrument, polypharmacy could be focused on and adverse reactions such as hospitalizations, falls, and cognitive impairment could be avoided. The purpose of this DNP project is to investigate the impact of polypharmacy on older adults and what is available in the literature to address this problem in primary care. Then implement a streamlined Polypharmacy Protocol in this type of setting to investigate its positive and negative attributes for future use to apply to the problem of polypharmacy

Letter from G. T. Skinner to Theophilus Brown Larimore

Letter from G. T. Skinner to Theophilus Brown Larimore. The three-page handwritten letter is dated 19 February 1913. A transcript of the letter is included in the item PDF

Chimneys and Fireplaces

Discusses chimney and fireplace design with an emphasis on safety and reducing hazards