2,014 research outputs found
A discussion on particle number and quantum indistinguishability
The concept of individuality in quantum mechanics shows radical differences
from the concept of individuality in classical physics, as E. Schroedinger
pointed out in the early steps of the theory. Regarding this fact, some authors
suggested that quantum mechanics does not possess its own language, and
therefore, quantum indistinguishability is not incorporated in the theory from
the beginning. Nevertheless, it is possible to represent the idea of quantum
indistinguishability with a first order language using quasiset theory (Q). In
this work, we show that Q cannot capture one of the most important features of
quantum non individuality, which is the fact that there are quantum systems for
which particle number is not well defined. An axiomatic variant of Q, in which
quasicardinal is not a primitive concept (for a kind of quasisets called finite
quasisets), is also given. This result encourages the searching of theories in
which the quasicardinal, being a secondary concept, stands undefined for some
quasisets, besides showing explicitly that in a set theory about collections of
truly indistinguishable entities, the quasicardinal needs not necessarily be a
primitive concept.Comment: 46 pages, no figures. Accepted by Foundations of Physic
Research investigation into the Ventura River watershed: Geoliteracy, stormwater, and community activity
Presently, scientific communities are confronting Earth’s foremost environmental issues using best management practices. However, an increase for need in the synthesis of socio-ecological principles using a multi- and trans-disciplinary approach is required for solutions that benefit both nature and humans. To examine whether a community perceives stormwater runoff as both a local resource and threat to coastal water quality, an online survey of the Ventura River watershed community probed local residents’ understanding of watershed knowledge, beliefs, and behavior with regards to their local environment as it pertained to water resources, especially as affected by human activity. Analysis of 144 participants’ responses and their self-reported water activity, water activity frequency, and perceptions of Ventura River’s discharge and stormwater runoff reveals the community’s behavior regarding exposure to poor water quality in a local coastal environment and, ultimately, the survey participants’ level of geoliteracy concerning their local watershed. A statistical analysis between categorical variables of the survey questions examines relationships between self-reported waterborne illness symptoms and the water activities that participants enjoy regularly and/or perform for work. The survey responses demonstrated common themes in water knowledge that exist throughout this particular coastal community. Additionally, through the use of an optical and historical classification system, the Ventura River’s sediment discharge was examined both remotely and in situ. Multispectral ocean color satellite sensors have been useful in monitoring the water quality of Case 2 waters. Particularly, after severe storm events contaminants can be carried along with storm runoff from urban storm drains and Mediterranean river mouths which then enter coastal and recreationally trafficked water. Earth scientists have observed poor water quality occurring offshore in Case 2 waters near major river mouths and urban areas causing the coastal water column to deteriorate in quality
Modality, Potentiality and Contradiction in Quantum Mechanics
In [11], Newton da Costa together with the author of this paper argued in
favor of the possibility to consider quantum superpositions in terms of a
paraconsistent approach. We claimed that, even though most interpretations of
quantum mechanics (QM) attempt to escape contradictions, there are many hints
that indicate it could be worth while to engage in a research of this kind.
Recently, Arenhart and Krause [1, 2, 3] have raised several arguments against
this approach and claimed that, taking into account the square of opposition,
quantum superpositions are better understood in terms of contrariety
propositions rather than contradictory propositions. In [17] we defended the
Paraconsistent Approach to Quantum Superpositions (PAQS) and provided arguments
in favor of its development. In the present paper we attempt to analyze the
meanings of modality, potentiality and contradiction in QM, and provide further
arguments of why the PAQS is better suited, than the Contrariety Approach to
Quantum Superpositions (CAQS) proposed by Arenhart and Krause, to face the
interpretational questions that quantum technology is forcing us to consider.Comment: Published in: New Directions in Paraconsistent Logic, J-Y B\'eziau M.
Chakraborty & S. Dutta (Eds.), Springer, in press. arXiv admin note: text
overlap with arXiv:1404.518
Working memory and attention in choice.
We study the role of attention and working memory in choices where options are presented sequentially rather than simultaneously. We build a model where a costly attention effort is chosen, which can vary over time. Evidence is accumulated proportionally to this effort and the utility of the reward. Crucially, the evidence accumulated decays over time. Optimal attention allocation maximizes expected utility from final choice; the optimal solution takes the decay into account, so attention is preferentially devoted to later times; but convexity of the flow attention cost prevents it from being concentrated near the end. We test this model with a choice experiment where participants observe sequentially two options. In our data the option presented first is, everything else being equal, significantly less likely to be chosen. This recency effect has a natural explanation with appropriate parameter values in our model of leaky evidence accumulation, where the decline is stronger for the option observed first. Analysis of choice, response time and brain imaging data provide support for the model. Working memory plays an essential role. The recency bias is stronger for participants with weaker performance in working memory tasks. Also activity in parietal areas, coding the stored value in working, declines over time as predicted
Perceptions of Incivility Among Students and Faculty in Entry-Level Health Professional Programs
Purpose: Online education is growing in popularity but has the potential to result in cyber incivility leading to disruptions in the learning environment. There is little known about the differences in attitudes between students and faculty in the online learning experience regarding cyber civility. The purpose of this study was to analytically measure student and faculty perceptions and attitudes of cyber incivility. Methods: A convenience sample of 180 (34 faculty and 146 students) participants from a health care university were recruited. A 27-item survey was given to record the perceptions of students and faculty on issues of cyber civility. An exploratory factor analysis was completed to validate the survey tool and determine the factors that made up the survey. A Mann Whitney U test was conducted to determine significant differences between student and faculty perceptions on the survey items. Results: Four factors were identified of the retained 19 items after the exploratory factor analysis: attitudes, presentation, appearance, and multitasking. There was a significant difference on 10 of the remaining survey items between students and faculty. Conclusions: Faculty perceived unprofessional dress, multitasking, and active display of complaints in the virtual environment more uncivil and disruptive than students. The themes show the differences between students and faculty perceptions in online platforms in healthcare educational programs. These differences highlight the need for healthcare educational programs to focus on strategies that align student and faculty expectations to positively impact the dynamics of the class and enhance learning in the virtual environment
Prospects for probing the gluon density in protons using heavy quarkonium hadroproduction
We examine carefully bottomonia hadroproduction in proton colliders,
especially focusing on the LHC, as a way of probing the gluon density in
protons. To this end we develop some previous work, getting quantitative
predictions and concluding that our proposal can be useful to perform
consistency checks of the parameterization sets of different parton
distribution functions.Comment: LaTeX, 14 pages, 6 EPS figure
Dating archaeological copper using electrochemical impedance spectroscopy. Comparison with voltammetry of microparticles dating
[EN] A methodology for dating copper/bronze archaeological objects aged under atmospheric environments using electrochemical impedance spectroscopy (EIS) is described. The method is based on the measurement of resistance associated to the growth of corrosion layers in EIS recorded upon immersion of the pieces in mineral water and applying a bias potential for the reduction of dissolved oxygen. Theoretical expressions for the time variation of such resistance following a potential rate law are presented. Equivalent expressions are derived and applied for estimating the variation of the tenorite/cuprite ratio from their specific voltammetric signals using voltammetry of microparticles data. Calibration curves were constructed from a set of well-documented coins.Financial support from the MEC Projects CTQ2011-28079-CO3-01 and 02 and CTQ2014-53736-C3-2-P which are supported with ERDF funds is gratefully acknowledged.Domenech Carbo, A.; Capelo, S.; Piquero-Cilla, J.; Domenech Carbo, MT.; Barrio, J.; Fuentes, A.; Al Sekhaneh, W. (2016). Dating archaeological copper using electrochemical impedance spectroscopy. Comparison with voltammetry of microparticles dating. Materials and Corrosion. 67(2):120-129. https://doi.org/10.1002/maco.201408048S120129672Friedman, I., & Smith, R. L. (1960). Part I, The Development of the Method. American Antiquity, 25(4), 476-493. doi:10.2307/276634Reich, S., Leitus, G., & Shalev, S. (2003). Measurement of corrosion content of archaeological lead artifacts by their Meissner response in the superconducting state; a new dating method. New Journal of Physics, 5, 99-99. doi:10.1088/1367-2630/5/1/399Scholz, F., Schröder, U., Meyer, S., Brainina, K. 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Analytical Chemistry, 83(14), 5639-5644. doi:10.1021/ac200731qDoménech-Carbó, A., Doménech-Carbó, M. T., Capelo, S., Pasíes, T., & Martínez-Lázaro, I. (2014). Dating Archaeological Copper/Bronze Artifacts by Using the Voltammetry of Microparticles. Angewandte Chemie International Edition, 53(35), 9262-9266. doi:10.1002/anie.201404522Benarie, M., & Lipfert, F. L. (1986). A general corrosion function in terms of atmospheric pollutant concentrations and rain pH. Atmospheric Environment (1967), 20(10), 1947-1958. doi:10.1016/0004-6981(86)90336-7Strandberg, H. (1998). Reactions of copper patina compounds—II. influence of sodium chloride in the presence of some air pollutants. Atmospheric Environment, 32(20), 3521-3526. doi:10.1016/s1352-2310(98)00058-2Cano, E., Lafuente, D., & Bastidas, D. M. (2009). Use of EIS for the evaluation of the protective properties of coatings for metallic cultural heritage: a review. Journal of Solid State Electrochemistry, 14(3), 381-391. doi:10.1007/s10008-009-0902-6Hernandez-Escampa, M., Gonzalez, J., & Uruchurtu-Chavarin, J. (2009). Electrochemical assessment of the restoration and conservation of a heavily corroded archaeological iron artifact. Journal of Applied Electrochemistry, 40(2), 345-356. doi:10.1007/s10800-009-0003-3Angelini, E., Grassini, S., Parvis, M., & Zucchi, F. (2011). An in situ investigation of the corrosion behaviour of a weathering steel work of art. Surface and Interface Analysis, 44(8), 942-946. doi:10.1002/sia.3842Grassini, S., Angelini, E., Parvis, M., Bouchar, M., Dillmann, P., & Neff, D. (2013). An in situ corrosion study of Middle Ages wrought iron bar chains in the Amiens Cathedral. Applied Physics A, 113(4), 971-979. doi:10.1007/s00339-013-7724-1Doménech-Carbó, A., Doménech-Carbó, M. T., Peiró-Ronda, M. A., Martínez-Lázaro, I., & Barrio-Martín, J. (2012). Application of the voltammetry of microparticles for dating archaeological lead using polarization curves and electrochemical impedance spectroscopy. Journal of Solid State Electrochemistry, 16(7), 2349-2356. doi:10.1007/s10008-012-1668-9Degrigny, C., Guibert, G., Ramseyer, S., Rapp, G., & Tarchini, A. (2009). Use of E corr vs time plots for the qualitative analysis of metallic elements from scientific and technical objects: the SPAMT Test Project. Journal of Solid State Electrochemistry, 14(3), 425-435. doi:10.1007/s10008-009-0890-6Souissi, N., Bousselmi, L., Khosrof, S., & Triki, E. (2004). Voltammetric behaviour of an archeaological bronze alloy in aqueous chloride media. Materials and Corrosion, 55(4), 284-292. doi:10.1002/maco.200303719Souissi, N., Triki, E., Bousselmi, L., & Khosrof, S. (2006). Comparaison between archaeological and artificially aged bronze interfaces. Materials and Corrosion, 57(10), 794-799. doi:10.1002/maco.200503974Souissi, N., & Triki, E. (2009). Characterization of ethnographic copper corrosion. Materials and Corrosion, 60(4), 262-268. doi:10.1002/maco.200805068Mata, A. L., Salta, M. M. L., Neto, M. M. M., Mendonça, M. H., & Fonseca, I. T. E. (2010). Characterization of two Roman coins from an archaeological site in Portugal. Materials and Corrosion, 61(3), 205-210. doi:10.1002/maco.200905284Feliu, S., Morcillo, M., & Feliu, S. (1993). The prediction of atmospheric corrosion from meteorological and pollution parameters—II. Long-term forecasts. Corrosion Science, 34(3), 415-422. doi:10.1016/0010-938x(93)90113-uSpence, J. W., Haynie, F. H., Lipfert, F. W., Cramer, S. D., & McDonald, L. G. (1992). Atmospheric Corrosion Model for Galvanized Steel Structures. CORROSION, 48(12), 1009-1019. doi:10.5006/1.3315903Bhattacharjee, S., Roy, N., Dey, A. K., & Banerjee, M. K. (1993). Statistical appraisal of the atmospheric corrosion of mild steel. Corrosion Science, 34(4), 573-581. doi:10.1016/0010-938x(93)90273-jKobus, J. (2000). Long-term atmospheric corrosion monitoring. Materials and Corrosion, 51(2), 104-108. doi:10.1002/(sici)1521-4176(200002)51:23.0.co;2-vBalasubramaniam, R., Laha, T., & Srivastava, A. (2004). Long term corrosion behaviour of copper in soil: A study of archaeological analogues. Materials and Corrosion, 55(3), 194-202. doi:10.1002/maco.200303723Natesan, M., Venkatachari, G., & Palaniswamy, N. (2006). Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India. Corrosion Science, 48(11), 3584-3608. doi:10.1016/j.corsci.2006.02.006Doménech, A., Doménech-Carbó, M. T., Pasies, T., & del Carmen Bouzas, M. (2012). Modeling Corrosion of Archaeological Silver-Copper Coins Using the Voltammetry of Immobilized Particles. Electroanalysis, 24(10), 1945-1955. doi:10.1002/elan.201200252Rosas-Camacho, O., Uquidi-Macdonald, M., & Macdonald, D. D. (2009). Deterministic Modeling of the Corrosion of Low-Carbon Steel by Dissolved Carbon Dioxide and the Effect of Acetic Acid. I-Effect of Carbon Dioxide. doi:10.1149/1.3259806Macdonald, D., & Englehardt, G. (2010). The Point Defect Model for Bi-Layer Passive Films. doi:10.1149/1.3496427Sharifi-Asl, S., Taylor, M. L., Lu, Z., Engelhardt, G. R., Kursten, B., & Macdonald, D. D. (2013). Modeling of the electrochemical impedance spectroscopic behavior of passive iron using a genetic algorithm approach. Electrochimica Acta, 102, 161-173. doi:10.1016/j.electacta.2013.03.143Macdonald, D. D. (2011). The history of the Point Defect Model for the passive state: A brief review of film growth aspects. Electrochimica Acta, 56(4), 1761-1772. doi:10.1016/j.electacta.2010.11.005Doménech-Carbó, A., Lastras, M., Rodríguez, F., Cano, E., Piquero-Cilla, J., & Osete-Cortina, L. (2013). Monitoring stabilizing procedures of archaeological iron using electrochemical impedance spectroscopy. 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Layer-by-layer identification of copper alteration products in metallic works of art using the voltammetry of microparticles. Analytica Chimica Acta, 680(1-2), 1-9. doi:10.1016/j.aca.2010.09.002Doménech, A., Doménech-Carbó, M. T., Pasies, T., & Bouzas, M. C. (2011). Application of Modified Tafel Analysis to the Identification of Corrosion Products on Archaeological Metals Using Voltammetry of Microparticles. Electroanalysis, 23(12), 2803-2812. doi:10.1002/elan.201100577Li, W. S., Cai, S. Q., & Luo, J. L. (2004). Chronopotentiometric Responses and Capacitance Behaviors of Passive Film Formed on Iron in Borate Buffer Solution. Journal of The Electrochemical Society, 151(4), B220. doi:10.1149/1.1667521Liu, W., Zhang, H., Qu, Z., Zhang, Y., & Li, J. (2009). Corrosion behavior of the steel used as a huge storage tank in seawater. Journal of Solid State Electrochemistry, 14(6), 965-973. doi:10.1007/s10008-009-0886-2Toledo-Matos, L. A., & Pech-Canul, M. A. (2010). 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Revision of food composition tables used to estimate nutrient intake in Ecuador
Las tablas y bases de datos de composición de alimentos (TCA/BDCA) son herramientas de valoración dietética. Objetivo: identificar las diferentes TCA empleadas como instrumento para estimar ingesta de nutrientes en Ecuador. La recogida de información se realizó a través de informadores-clave, cuestionarios auto-administrados, complementadas con búsquedas webs institucionales. A las TCA/BDCA identificadas se realizó análisis de contenido sobre variables generales y metodológicas. TCA referidas: Ecuatoriana-1965 (70%), INCAP (60%), México (60%). Se reportaron 7 TCA y 3 BDCA, 8 Latinoamericanas y 2 Españolas. Una TCA elaborada por método-directo (ecuatoriana), 7 por método-indirecto, 2 sin-información. 6 TCA/BDCA definieron nutrientes, 9 refirieron valores (100g/ porción-comestible). Para realizar una correcta estimacion de ingesta, es necesario contar con una TCA ecuatoriana actualizada. Ecuatoriana-1965 presenta pocos alimentos analizados y, métodos analíticos no-actualizados. Las autoras aconsejan el uso de TCA-INCAP, dado que la lista de alimentos refleja similitud con alimentos ecuatorianos. Además INCAP dispone BDCA para incorporar recetas.Tables and food composition databases (FCT/FCDB) are tools used for dietetic evaluation. Objective: to identify different FCT used as an instrument to estimate the nutrient intake in Ecuador. The collection of data was made through key informants -self completed questionnaires-, supplemented with institutional web research. An analysis of content was performed to the identified FCT/FCDB by general and methodological variables. Referenced tables were: Ecuadorian-1965 (70%), INCAP (60%), México (60%). 7 FCT and 3 FCDB were reported, 8 from Latin America and 2 from Spain. One table was constructed by direct method (Ecuadorian-table), 7 by indirect, and 1 had no Information. 6 FCT/FCDB defined the nutrients, 9 expressed values per (100g/ edible portion). In order to asses a proper ingest in Ecuador, it is necessary to have an updated ecuadorian FCT, Ecuadorian-1965 shows few analyzed foods and, not updated analytic techniques. The authors recommend the usage of FCT-INCAP, due to its food list reflects similarities with ecuadorian foods. In addition, INCAP disposes of a FCDB in which ecuadorian recipes can be included
Contextual logic for quantum systems
In this work we build a quantum logic that allows us to refer to physical
magnitudes pertaining to different contexts from a fixed one without the
contradictions with quantum mechanics expressed in no-go theorems. This logic
arises from considering a sheaf over a topological space associated to the
Boolean sublattices of the ortholattice of closed subspaces of the Hilbert
space of the physical system. Differently to standard quantum logics, the
contextual logic maintains a distributive lattice structure and a good
definition of implication as a residue of the conjunction.Comment: 16 pages, no figure
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