1,341 research outputs found
Accuracy of the TRIA3 thick shell element
The accuracy of the new TRIA3 thick shell element is assessed via comparison with a theoretical solution for thick homogeneous and honeycomb flat simply supported plates under the action of a uniform pressure load. The theoretical thick plate solution is based on the theory developed by Reissner and includes the effects of transverse shear flexibility which are not included in the thin plate solutions based on Kirchoff plate theory. In addition, the TRIA3 is assessed using a set of finite element test problems developed by the MacNeal-Schwendler Corp. (MSC). Comparison of the COSMIC TRIA3 element as well as those from MSC and Universal Analytics Inc. (UAI) for these problems is presented. The current COSMIC TRIA3 element is shown to have excellent comparison with both the theoretical solutions and also those from the two commercial versions of NASTRAN with which it is compared
A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions
NASAs Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair Lunar Lander and the Extravehicular Activities (EVA) advanced Lunar surface spacesuit. These customers require safe, reliable batteries with extremely high specific energy as compared to state-of-the-art. The specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery-level at 0 degrees Celsius ( C) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation between 0 and 30 C and 200 cycles are targeted. Electrode materials that were considered include layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. Advanced cell chemistry options were evaluated with respect to multiple quantitative and qualitative attributes while considering their projected performance at the end of the available development timeframe. Following a rigorous ranking process, a chemistry that combines a lithiated nickel manganese cobalt oxide Li(LiNMC)O2 cathode with a silicon-based composite anode was selected as the technology that can potentially offer the best combination of safety, specific energy, energy density, and likelihood of success
Acidification of protein-enriched rice starch doughs: effects on breadmaking
The impact of acid incorporation (acetic + lactic, 0.5 %) into rice starch-based doughs enriched with different proteins (egg albumin, calcium caseinate, pea and soy protein isolates) at different doses (0, 5 and 10 %) was investigated on dough proofing and thermal properties, and bread quality evaluated from physical and sensory measurements. Proteins from vegetable sources led to breads with lower-specific volume and harder crumb, effects being magnified with protein dose and reduced with acid addition. Incorporation of proteins from animal source resulted in different behaviours according to the protein type, dosage and acidification. Protein addition increased the dough pH and total titratable acidity and reduced the impact of acid addition on dough acidity. Albumin-added doughs had significantly higher temperature of gelatinization than most of the other supplemented doughs, while vegetable proteins led to significantly lower gelatinization enthalpy than the control dough. Acid addition affected dough proofing and significantly improved the volume and texture of protein-enriched breads without detriment of either odour or taste.The research was supported by the Spanish Institutions Ministerio de Economía y Competitividad and the European Regional Development Fund (FEDER) (Projects AGL2012-35088 and AGL2011-22669), and Comunidad de Castilla y León (Project VA252A12-2).Marina Villanueva thanks the Junta de Castilla y León doctorate grantPeer Reviewe
Asymptotic Symmetries of Maxwell Chern-Simons Gravity with Torsion
We present a three-dimensional Chern-Simons gravity based on a deformation of
the Maxwell algebra. This symmetry allows introduction of a non-vanishing
torsion to the Maxwell Chern-Simons theory, whose action recovers the
Mielke-Baelker model for particular values of the coupling constants. By
considering suitable boundary conditions, we show that the asymptotic symmetry
is given by the algebra with
three independent central charges.Comment: 18 page
Occurrence of Clinical and Sub-Clinical Mastitis in Dairy Herds in the West Littoral Region in Uruguay
Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20°C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300 000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%
Review of Particle Physics
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143
new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the
recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical
particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search
limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs
Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology,
Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily
revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances.
The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume
2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented
in the Listings.
The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov)
and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary
Tables and essential tables, figures, and equations from selected review articles is available in print, as a web version
optimized for use on phones, and as an Android app.United States Department of Energy (DOE) DE-AC02-05CH11231government of Japan (Ministry of Education, Culture, Sports, Science and Technology)Istituto Nazionale di Fisica Nucleare (INFN)Physical Society of Japan (JPS)European Laboratory for Particle Physics (CERN)United States Department of Energy (DOE
Wrinkling of a bilayer membrane
The buckling of elastic bodies is a common phenomenon in the mechanics of
solids. Wrinkling of membranes can often be interpreted as buckling under
constraints that prohibit large amplitude deformation. We present a combination
of analytic calculations, experiments, and simulations to understand wrinkling
patterns generated in a bilayer membrane. The model membrane is composed of a
flexible spherical shell that is under tension and that is circumscribed by a
stiff, essentially incompressible strip with bending modulus B. When the
tension is reduced sufficiently to a value \sigma, the strip forms wrinkles
with a uniform wavelength found theoretically and experimentally to be \lambda
= 2\pi(B/\sigma)^{1/3}. Defects in this pattern appear for rapid changes in
tension. Comparison between experiment and simulation further shows that, with
larger reduction of tension, a second generation of wrinkles with longer
wavelength appears only when B is sufficiently small.Comment: 9 pages, 5 color figure
La prensa durante la primera parte de la Restauración: la edad dorada del modelo político y el fracaso del Nuevo Periodismo
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