10,969 research outputs found
A slab model for computing ground temperature in climate models
A method is developed for computing the ground temperature accurately over both the diurnal and annual cycles. The ground is divided vertically into only two or three slabs, resulting in very efficient computation. Seasonal storage and release of heat is incorporated, and thus the method is well suited for use in climate models
Identification of behaviour change techniques and engagement strategies to design a smartphone app to reduce alcohol consumption using a formal consensus method
Background: Digital interventions to reduce excessive alcohol consumption have the potential to have a broader reach and be more cost-effective than traditional brief interventions. However, there is not yet a strong evidence base on their ability to engage users or on their effectiveness. Objective: This study aimed to identify the behaviour change techniques (BCTs) and engagement strategies most worthy of further study by inclusion in a smartphone application (app) to reduce alcohol consumption, using formal expert consensus methods. Methods: The first phase of the study consisted of a Delphi exercise with three rounds. It was conducted with seven international experts in the field of alcohol and/or behaviour change. In the first round, experts identified BCTs most likely to be effective at reducing alcohol consumption and strategies most likely to engage users with an app; these were rated in the second round; and those rated as effective by at least four out of seven participants were ranked in the third round. The rankings were analysed using Kendall’s W coefficient of concordance, which indicates consensus between participants. The second phase consisted of a new, independent group of experts (n=43) ranking the BCTs that were identified in the first phase. The correlation between the rankings of the two groups was assessed using Spearman’s rank correlation coefficient. Results: Twelve BCTs were identified as likely to be effective. There was moderate agreement among the experts over their ranking (W=.465, χ2(11)=35.77, P<.001) and the BCTs receiving the highest mean rankings were self-monitoring, goal-setting, action planning, and feedback in relation to goals. There was a significant correlation between the ranking of the BCTs by the group of experts who identified them and a second independent group of experts (Spearman’s rho=.690, P=.01). Seventeen responses were generated for strategies likely to engage users. There was moderate agreement among experts on the ranking of these engagement strategies (W=.563, χ2(15)=59.16, P<.001) and those with the highest mean rankings were ease of use, design – aesthetic, feedback, function, design – ability to change design to suit own preferences, tailored information, and unique smartphone features. Conclusions: The BCTs with greatest potential to include in a smartphone app to reduce alcohol consumption were judged by experts to be self-monitoring, goal-setting, action planning, and feedback in relation to goals. The strategies most likely to engage users were ease of use, design, tailoring of design and information, and unique smartphone features
Can Synchronicity be Invoked? Synchronistic Inquiry and the Nature of Meaning
This paper examines synchronicity, the concept first proposed by Carl Jung, of an “acausal connecting principle” (Jung, 1952), or, a meaningful coincidence linking inner and outer events, from three distinct angles. First, it reviews the theoretical framework for synchronicity, and specifically explores the nature of meaning as an arbiter of synchronicity. The paper then asks whether, considering the co-determined nature of meaning, synchronicity can possibly be consciously invoked. Drawing upon anecdotal examples from personal experience, the outlines of a possible research process, personal synchronistic inquiry, are proposed. Finally, this paper presents a personal attempt to implement the research protocol outlined above in the form of a case study, and briefly examines the themes emergent in the data therein. As itself an expression of synchronistic inquiry, such emergent themes include the nature of time, apocalypticism, sexuality, and messianic consciousness
Causal sites as quantum geometry
We propose a structure called a causal site to use as a setting for quantum
geometry, replacing the underlying point set. The structure has an interesting
categorical form, and a natural "tangent 2-bundle," analogous to the tangent
bundle of a smooth manifold. Examples with reasonable finiteness conditions
have an intrinsic geometry, which can approximate classical solutions to
general relativity. We propose an approach to quantization of causal sites as
well.Comment: 21 pages, 3 eps figures; v2: added references; to appear in JM
Thermal conductivity of heterogeneous mixtures and lunar soils
The theoretical evaluation of the effective thermal conductivity of granular materials is discussed with emphasis upon the heat transport properties of lunar soil. The following types of models are compared: probabilistic, parallel isotherm, stochastic, lunar, and a model based on nonlinear heat flow system synthesis
Seasons Fall 2018 Volume 47 Number 3
Highlights : Thompson-Morris Plot Restoration Complete Botany for Beginners Preserving Our Tree Canopy Three Great Native Trees ArbNet Accreditationhttps://repository.upenn.edu/morrisarboretum_seasons/1000/thumbnail.jp
Spin Foam Models of Matter Coupled to Gravity
We construct a class of spin foam models describing matter coupled to
gravity, such that the gravitational sector is described by the unitary
irreducible representations of the appropriate symmetry group, while the matter
sector is described by the finite-dimensional irreducible representations of
that group. The corresponding spin foam amplitudes in the four-dimensional
gravity case are expressed in terms of the spin network amplitudes for
pentagrams with additional external and internal matter edges. We also give a
quantum field theory formulation of the model, where the matter degrees of
freedom are described by spin network fields carrying the indices from the
appropriate group representation. In the non-topological Lorentzian gravity
case, we argue that the matter representations should be appropriate SO(3) or
SO(2) representations contained in a given Lorentz matter representation,
depending on whether one wants to describe a massive or a massless matter
field. The corresponding spin network amplitudes are given as multiple
integrals of propagators which are matrix spherical functions.Comment: 30 pages, 9 figures, further remarks and references added. Version to
appear in Class. Quant. Gra
Defect Specific Penetrants
The failure to detect small through-the-thickness flaws in non-metallic coatings on metallic substrates can lead to corrosion rates several orders of magnitude greater than those of the bare metal. Therefore, the detection of such defects has high priority even though presently used inspection procedures are both expensive and difficult to perform. It has recently been shown that it is possible to make a penetrant that can detect those through-thickness flaws to the exclusion of all others. These penetrants are made by adding chelating agents to a carrier fluid such as an alcohol. The chelating agent becomes fluorescent when it contacts a metal substrate. Initial work utilized the chelating agent 8-hydroxy quinoline, and is sensitive to most metals. Current work is concentrating on chelating agents that are specific to certain metals. Thus, cracks in chromium coatings or steel can be detected if they penetrate on the steel base. Work on organic and biological agents show promise
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