Low-energy electron transport with the method of discrete ordinates

The one-dimensional discrete ordinates code ANISN was adapted to transport low energy (a few MeV) electrons. Calculated results obtained with ANISN were compared with experimental data for transmitted electron energy and angular distribution data for electrons normally incident on aluminum slabs of various thicknesses. The calculated and experimental results are in good agreement for a thin slab (0.2 of the electron range), but not for the thicker slabs (0.6 of the electron range). Calculated results obtained with ANISN were also compared with results obtained using Monte Carlo methods

Cinq façons de prendre en main la mise en place d'un modèle d'évaluation de programmes dans les académies vouées au développement professionnel des formateurs en sciences de la santé

The proliferation of health professions educator academies across Canada and the United States illustrates the value they hold for faculty and institutions.  Yet, establishing and evaluating the efficacy of them through program evaluation can be challenging. Moreover, academy leadership often lack the time, bandwidth skillset and personnel to undertake rigorous program evaluation efforts. We outline a step-by-step guide for getting a grip on evaluating health professions educator academies. Developing a plan for program evaluation in advance of any new academy initiative helps to ensure the academy calibrates and re-calibrates to accomplish outcomes and meet stakeholder expectations.  It also provides a mechanism for tracking academy impact, which strengthens requests for funding, promotes sustainability and encourages continued buy-in and support from institutional stakeholders. For all of these reasons, we present the following recommendations: apply the relevant program evaluation framework(s); identify resources for program evaluation; prepare to tell your academy’s story; list desired program outcomes; establish a data collection plan; and obtain institutional review board approval.La prolifération des écoles (« académies ») vouées au développement professionnel des formateurs en sciences de la santé au Canada et aux États-Unis témoigne de l’importance que leur accordent le corps enseignant et les établissements d’enseignement.  Pourtant, il peut s'avérer difficile d'établir et d'évaluer leur efficacité au moyen d'une évaluation de programme. De plus, les responsables de ces écoles manquent souvent de temps, de compétences et de personnel pour entreprendre une évaluation rigoureuse de leurs programmes. Nous présentons un guide étape par étape pour évaluer les écoles vouées au développement professionnel des formateurs en sciences de la santé. L'élaboration d'un plan d'évaluation des programmes avant toute nouvelle initiative de l’école permet de s'assurer que celle-ci s’ajuste et se réajuste pour obtenir des résultats et répondre aux attentes des personnes concernées. Ce plan fournit également un mécanisme de suivi des retombées de l'école et ainsi renforcer ses demandes de financement, favoriser sa pérennité et encourager l'adhésion et le soutien continus des partenaires institutionnels. Pour toutes ces raisons, nous présentons les recommandations suivantes : appliquer le(s) cadre(s) d'évaluation de programme pertinent(s); identifier les ressources pour l'évaluation de programme; se préparer à raconter l'histoire de votre école; dresser la liste des résultats de programme souhaités; établir un plan de collecte de données et obtenir l'approbation du comité d'examen institutionnel

Coherent states, constraint classes, and area operators in the new spin-foam models

Recently, two new spin-foam models have appeared in the literature, both motivated by a desire to modify the Barrett-Crane model in such a way that the imposition of certain second class constraints, called cross-simplicity constraints, are weakened. We refer to these two models as the FKLS model, and the flipped model. Both of these models are based on a reformulation of the cross-simplicity constraints. This paper has two main parts. First, we clarify the structure of the reformulated cross-simplicity constraints and the nature of their quantum imposition in the new models. In particular we show that in the FKLS model, quantum cross-simplicity implies no restriction on states. The deeper reason for this is that, with the symplectic structure relevant for FKLS, the reformulated cross-simplicity constraints, in a certain relevant sense, are now \emph{first class}, and this causes the coherent state method of imposing the constraints, key in the FKLS model, to fail to give any restriction on states. Nevertheless, the cross-simplicity can still be seen as implemented via suppression of intertwiner degrees of freedom in the dynamical propagation. In the second part of the paper, we investigate area spectra in the models. The results of these two investigations will highlight how, in the flipped model, the Hilbert space of states, as well as the spectra of area operators exactly match those of loop quantum gravity, whereas in the FKLS (and Barrett-Crane) models, the boundary Hilbert spaces and area spectra are different.Comment: 21 pages; statements about gamma limits made more precise, and minor phrasing change

Physical boundary state for the quantum tetrahedron

We consider stability under evolution as a criterion to select a physical boundary state for the spinfoam formalism. As an example, we apply it to the simplest spinfoam defined by a single quantum tetrahedron and solve the associated eigenvalue problem at leading order in the large spin limit. We show that this fixes uniquely the free parameters entering the boundary state. Remarkably, the state obtained this way gives a correlation between edges which runs at leading order with the inverse distance between the edges, in agreement with the linearized continuum theory. Finally, we give an argument why this correlator represents the propagation of a pure gauge, consistently with the absence of physical degrees of freedom in 3d general relativity.Comment: 20 pages, 6 figure

Numerical indications on the semiclassical limit of the flipped vertex

We introduce a technique for testing the semiclassical limit of a quantum gravity vertex amplitude. The technique is based on the propagation of a semiclassical wave packet. We apply this technique to the newly introduced "flipped" vertex in loop quantum gravity, in order to test the intertwiner dependence of the vertex. Under some drastic simplifications, we find very preliminary, but surprisingly good numerical evidence for the correct classical limit.Comment: 4 pages, 8 figure

Holography in the EPRL Model

In this research announcement, we propose a new interpretation of the EPR quantization of the BC model using a functor we call the time functor, which is the first example of a CLa-ren functor. Under the hypothesis that the universe is in the Kodama state, we construct a holographic version of the model. Generalisations to other CLa-ren functors and connections to model category theory are considered.Comment: research announcement. Latex fil

Particle Size of Dry-rolled Corn Affects Starch Digestibility but Not Feedlot Performance

Dry-rolling corn is a common practice in feedlots located in the Midwestern and Northern Plains regions of the United States. Optimizing total digestive tract starch utilization in diets containing dry-rolled corn is essential for maximizing efficiency. However, recommendations often suggest that grain be coarsely cracked to avoid producing an excessive amount of fine material that could potentially increase the rate of fermentation, reduce rumen pH, and cause digestive disturbances. Wet distillers byproducts may be effectively used as a protein and energy source for feedlot finishing cattle and can replace a portion of the dry-rolled corn in the diet. The average geometric mean particle size of dry-rolled corn across all feedyards (n = 31) was 0.179 ± 0.035 in. with a range of 0.085 to 0.269 in. The objective of this study was to evaluate the effects of dry-rolled corn particle size on animal performance, carcass traits, and starch digestibility in feedlot finishing diets containing 20% wet distillers grains on a dry matter basis