Experimental vibro-acoustic analysis of the gear rattle induced by multi-harmonic excitation

The paper reports a wide vibro-acoustic experimental investigation of the gear rattle phenomenon induced by multiharmonic excitation. The analysis is performed by using different measurement techniques which allow some of the significant parameters in this type of investigation to be acquired on a specific test rig: the angular rotations of the gears by using encoders; the accelerations obtained from a triaxial accelerometer; the sound pressure level determined by employing both acoustic microphones; the correct evaluation of the acoustic sources by utilizing a p–v sound intensity probe. Performance indices were adopted to compare the dynamic behaviours of the system with respect to some parameters, such as the speed of the pinion, the fluctuations in the speed of the pinion and the lubrication conditions. The results of the comparative analysis show very good agreement between the vibro-acoustic measurements and the results from the encoder-based method; this has helped us to interpret the physical behaviour of the gear pair with respect to the impacts occurring between the teeth during the different phases of the phenomenon. Moreover, the study indicates interesting aspects of the effects of multi-harmonic excitation on the rattle phenomenon, with particular attention to the influence of lubrication on the reduction in the rattle noise

Controlling distant contacts to reduce disease spreading on disordered complex networks

In real social networks, person-to-person interactions are known to be heterogeneous, which can affect the way a disease spreads through a population, reaches a tipping point in the fraction of infected individuals, and becomes an epidemic. This property, called disorder, is usually associated with contact times between individuals and can be modeled by a weighted network, where the weights are related to normalized contact times ω. In this paper, we study the SIR model for disease spreading when both close and distant types of interactions are present. We develop a mitigation strategy that reduces only the time duration of distant contacts, which are easier to alter in practice. Using branching theory, supported by simulations, we found that the effectiveness of the strategy increases when the density f1 of close contacts decreases. Moreover, we found a threshold f̃1=Tc∕β below which the strategy can bring the system from an epidemic to a non-epidemic phase, even when close contacts have the longest time durations.Fil: Pérez, Ignacio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Trunfio, Paul A.. Boston University; Estados UnidosFil: la Rocca, Cristian Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina. Boston University; Estados UnidosFil: Braunstein, Lidia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina. Boston University; Estados Unido

Prácticas agrícolas y obras civiles ante procesos de desertización y degradación del suelo del Piedemonte de la Sierra de Córdoba

Fil: Abril, Ernesto Guillermo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Sacchi, Gabriela Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Cartografía y Conservación de Suelos; Argentina.Fil: Rocca, Ricardo José. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.En el piedemonte oriental de la Sierra de Córdoba (Argentina) la vegetación, como interfase entre clima y suelo, fue durante milenios un factor de regulación de los procesos morfodinámicos. La vulnerabilidad del suelo se manifiesta desde el cambio en el uso y manejo de la tierra. La deforestación alcanzó el pie de la sierra, abarcando suelos sin una capacidad de uso agrícola adecuado. La antropización fue abrupta y en un siglo se desarmó el complejo natural generando una disfunción hidrológica que aumentó la escorrentía y activó procesos erosivos generalizados. Las prácticas conservacionistas contribuyeron a atenuar los procesos, pero requirieron acciones conjuntas y sostenidas en el tiempo. Además de cambios progresivos de manejo, se necesitaron acciones de regulación de caudales, para no sobrepasar la capacidad receptiva de los campos aguas abajo. El área intervenida constituye una muestra de las posibilidades actuales de controlar la erosión y recuperar los suelos en un ambiente profundamente disturbado. Se asumió el problema a nivel de cuenca, acordando entre los productores y sellando las intenciones con obras de ingeniería conjuntas. La progresiva adecuación de las explotaciones rurales individuales fue acompañada con la ejecución de una presa de regulación. La labranza cero, el diseño de siembra en terrazas, el empastado marginal del parcelado y de zonas críticas, entre otras, y la captura y el manejo adecuado de las aguas superficiales, muestran un abordaje sistémico eficaz ante un problema grave y generalizado. Las observaciones realizadas sobre la iniciativa abarcan un período en el cual se analiza la situación con y sin proyecto, así como un prolongado monitoreo del funcionamiento del complejo. Queda en evidencia un proceso progresivo de estabilización, que condujo a la preservación y recomposición del suelo, y el manejo adecuado de los excedentes hídricos, mostrándose la factibilidad de aplicarlo con éxito en toda la región. El resultado del estudio permite advertir la eficacia del apoyo del productor a iniciativas que incluyen estudios hidrológicos, la aplicación de diseños de uso y laboreo del suelo y la ejecución de obras civiles complementarias. La experiencia muestra la necesidad del seguimiento constante de la situación mediante el empleo de imágenes de sensores remotos para detectar situaciones a corregir.Fil: Abril, Ernesto Guillermo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Sacchi, Gabriela Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Cartografía y Conservación de Suelos; Argentina.Fil: Rocca, Ricardo José. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Otras Ciencias de la Tierra y relacionadas con el Medio Ambient

An epidemic model for COVID-19 transmission in Argentina: Exploration of the alternating quarantine and massive testing strategies

The COVID-19 pandemic has challenged authorities at different levels of government administration aroundthe globe. When faced with diseases of this severity, it is useful for the authorities to have prediction tools to estimate in advance the impact on the health system as well as the human, material, and economic resources that will be necessary. In this paper, we construct an extended Susceptible?Exposed?Infected?Recovered modelthat incorporates the social structure of Mar del Plata, the 4◦ most inhabited city in Argentina and head ofthe Municipality of General Pueyrredón. Moreover, we consider detailed partitions of infected individualsaccording to the illness severity, as well as data of local health resources, to bring predictions closer to thelocal reality. Tuning the corresponding epidemic parameters for COVID-19, we study an alternating quarantinestrategy: a part of the population can circulate without restrictions at any time, while the rest is equally dividedinto two groups and goes on successive periods of normal activity and lockdown, each one with a durationof days. We also implement a random testing strategy with a threshold over the population. We found that = 7 is a good choice for the quarantine strategy since it reduces the infected population and, conveniently,it suits a weekly schedule. Focusing on the health system, projecting from the situation as of September 30,we foresee a difficulty to avoid saturation of the available ICU, given the extremely low levels of mobility thatwould be required. In the worst case, our model estimates that four thousand deaths would occur, of which30% could be avoided with proper medical attention. Nonetheless, we found that aggressive testing wouldallow an increase in the percentage of people that can circulate without restrictions, and the medical facilitiesto deal with the additional critical patients would be relatively low.Fil: Vassallo, Lautaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Pérez, Ignacio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Alvarez Zuzek, Lucila G.. University Of Georgetown; Estados UnidosFil: Amaya, Julián. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Torres, Marcos F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Valdez, Lucas Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: la Rocca, Cristian Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Braunstein, Lidia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin

Could YouTubeTM encourage men on prostate checks? A contemporary analysis

Objectives: To assess YouTube™ videos' quality on prostate checks, especially on the digital rectal exam (DRE), and to investigate if they can inform patients correctly and eradicate their beliefs and myths.Methods: A search using as keywords "digital rectal exam for prostate cancer" was performed on the YouTubeTM platform. We selected the first 100 videos. To assess video quality content, Patient Education Materials Assessment Tool for audio-visual content (PEMAT A/V) and Misinformation tool were used.Results: Seventy-three videos were suitable for the analyses. The median PEMAT A/V Understandability score and PEMAT A/V Actionability score were 46.2% (interquartile range [IQR]: 30.8-76.9) and 50.0% (IQR: 25.0-75.0), respectively. The medi-an PEMAT A/V Understandability and Actionability scores were 69.2% (IQR: 46.2-88.5) vs 46.2% (IQR: 30.8-61.5) (p = 0.01) and 100.0% (IQR: 87.5-100.0) vs 25.0% (IQR: 25.0-68.8)(p < 0.001), for healthcare workers vs patients, respectively. According to the Misinformation tool, the median misinforma-tion score of the overall videos was 2.2 (IQR:1.7-2.8). According to the target audience, the misinformation score was 2.8 (IQR: 2.4-3.5) vs 2.0 (IQR: 1.5-2.8) (p = 0.02), for healthcare workers vs patients, respectively. Conclusions: Currently, based on our analyses, YouTubeTM videos' quality on DRE resulted unsatisfactory according to the PEMAT A/V score and the Misinformation tool. Videos targeted to healthcare workers got higher quality scores if compared to videos targeted to patients. Therefore, YouTubeTM videos' may not be considered a reliable source of information on DRE for patients

The Italian National Project of Astrobiology-Life in Space-Origin, Presence, Persistence of Life in Space, from Molecules to Extremophiles

The \u2018\u2018Life in Space\u2019\u2019 project was funded in the wake of the Italian Space Agency\u2019s proposal for the development of a network of institutions and laboratories conceived to implement Italian participation in space astrobiology experiments

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe