Hydrodynamic excitations of trapped dipolar fermions

A single-component Fermi gas of polarized dipolar particles in a harmonic trap can undergo a mechanical collapse due to the attractive part of the dipole-dipole interaction. This phenomenon can be conveniently manipulated by the shape of the external trapping potential. We investigate the signatures of the instability by studying the spectrum of low-lying collective excitations of the system in the hydrodynamic regime. To this end, we employ a time-dependent variational method as well as exact numerical solutions of the hydrodynamic equations of the system.Comment: 4 pages, 2 eps figures, final versio

Fuzzy controller to compensate comunication loads in real-time

[EN] A Fuzzy Resource Manager (RM) to compensate communication loads in real-time systems is presented. The design is based on a new model of a Constant Bandwidth Server (CBS), which is responsible for assigning time slots to tasks with the highest priority when idle time is available. Assuming that each application can be executed at dierent service levels, without being below a minimum limit, a fuzzy approach is introduced that allows to adjust the time resources assigned to each task and to compensate non-linearities in time resources requests. The RM increases or decreases the virtual platform for each application and assigns a maximum process time budget for it, which is gradually used and refilled when depleted, without aecting the other applications. The scheme self-adjusts to sudden changes in applications process time requirements.[ES] Se presenta un administrador de recursos (RM) difuso para compensar las cargas de comunicación en sistemas en tiempo real. El diseño del RM se basa en un nuevo modelo de Servidor de Ancho de Banda Constante (CBS) que se encarga, a través de una plataforma virtual, de asignar tiempo de proceso a las tareas de mayor prioridad cuando existe capacidad disponible. Si se asume que cada aplicación puede ser ejecutada con diferentes niveles de servicio sin que este esté por debajo de un límite mínimo, se propone una aproximación difusa que permite actualizar de manera gradual los tiempos de proceso asignados a cada tarea. Esta aproximación permite compensar el comportamiento no lineal en las solicitudes de tiempo de proceso. El RM aumenta o disminuye la plataforma virtual para cada aplicación y le asigna un presupuesto máximo de tiempo de proceso, mismo que la aplicación usa gradualmente y que se reasigna al agotarse, sin por ello afectar el desempeño del resto de las aplicaciones. El esquema se auto-ajusta cuando ocurren a cambios repentinos en los requerimientos de tiempo de proceso de las aplicaciones.Este trabajo ha sido realizado parcialmente gracias al apoyo del CONACYT BECA 597175, PAPIIT IT100320 y PAPIIT IN104516.Aparicio-Santos, J.; Hermosillo-Gómez, J.; Benítez-Pérez, H.; Álvarez-Icaza, L. (2021). Controlador difuso para compensar cargas de comunicación en sistemas en tiempo real. Revista Iberoamericana de Automática e Informática industrial. 18(3):288-299. https://doi.org/10.4995/riai.2021.14544OJS288299183Abeni, L., Buttazzo, G., Dec 1998. Integrating multimedia applications in hard real-time systems. In: Proceedings 19th IEEE Real-Time Systems Symposium (Cat. No.98CB36279). pp. 4-13. https://doi.org/10.1109/REAL.1998.739726Aparicio, Santos, J. A., 2017. Diseño de un controlador difuso para compensar cargas de comunicación en tiempo real. Master's thesis, Universidad Nacional Autónoma de México, México.Bini, E., Buttazzo, G., Eker, J., Schorr, S., Guerra, R., Fohler, G., Arzen, K. E., Romero, V., Scordino, C., May 2011. Resource management on multicore systems: The actors approach. IEEE Micro 31 (3), 72-81. https://doi.org/10.1109/MM.2011.1Boutalis, Y., Theodoridis, D., Kottas, T., Christodoulou, M. A., 2014. System Identification and Adaptive Control: Theory and Applications of the Neurofuzzy and Fuzzy Cognitive Network Models. Springer.Buttazzo, G. C., 2011. Hard Real-Time Computing Systems: Predictable Scheduling Algorithms and Applications, 3rd Edition. Springer Publishing Company, Incorporated. Byeong Gi, L., Daeyoung, P., Hanbyul, S., 2009. Wireless Communications Resource Managemen. John Wiley and Sons.Byeong Gi, L., Daeyoung, P., Hanbyul, S., 2009. Wireless Communications Resource Managemen. John Wiley and Sons.Chasparis, G., Maggio, M., Arzen, K. E., Bini, E., June 2013. Distributed management of cpu resources for time-sensitive applications. In: 2013 American Control Conference. pp. 5305-5312. https://doi.org/10.1109/ACC.2013.6580666Chasparis, G. C., Maggio, M., Bini, E., Arzen, K.-E., 2016. Desing and implementation of distributed resource management for time-sensitive applications. Automatica 64, 44 - 53. https://doi.org/10.1016/j.automatica.2015.09.015Clark, R. K., 1990. Scheduling dependent real-time activities. Ph.D. thesis, USA, aAI9107552.Ganz, A., Ganz, Z., Wongthavarawat, K., 2003. Multimedia Wireless Networks: Technologies, Standards and QoS. Pearson Education.Horn, W., 1974. Some simple scheduling algorithms. Naval Research Logistics Quarterly 21 (1), 177-185. https://doi.org/10.1002/nav.3800210113IEEE Standard Glossary of Software Engineering Terminology. https://doi.org/10.1109/IEEESTD.1990.101064Litoiu, M., Tadei, R., 2001. Fuzzy scheduling with application to real-time systems. Fuzzy Sets and Systems 121 (3), 523 - 535. https://doi.org/10.1016/S0165-0114(99)00176-1Mahmoud, M., of Engineering, I., Technology, 2013. Distributed Control and Filtering for Industrial Systems. Control, Robotics and Sensors. Institution of Engineering and Technology. URL: https://books.google.com.mx/books?id=qWhWx2hRLYcC https://doi.org/10.1049/PBCE088EMok, A. K., Feng, X., May 2001. Resource partition for real-time systems. In: Proceedings Seventh IEEE Real-Time Technology and Applications Symposium. pp. 75-84. https://doi.org/10.1109/RTTAS.2001.929867Nesbit, K. J., Moreto, M., Cazorla, F. J., Ramirez, A., Valero, M., Smith, J. E., May 2008. Multicore resource management. IEEE Micro 28 (3), 6-16. https://doi.org/10.1109/MM.2008.43Quanser, 2012. USER MANUAL 3 DOF Gyroscope Experiment Set Up and Configuration. Quanser inc.Robert H. Cannon, J., 2003. Dynamics Of Physical Systems. Dover Publications, INC.Stankovic, J. A., 1988. Misconceptions about real-time computing: a serious problem for next-generation systems. Computer 21 (10), 10-19. https://doi.org/10.1109/2.7053Subrata, R., Zomaya, A. Y., Landfeldt, B., Oct 2008. A cooperative game framework for qos guided job allocation schemes in grids. IEEE Transactions on Computers 57 (10), 1413-1422. https://doi.org/10.1109/TC.2008.79Tanaka, K., Ikeda, T., Wang, H. O., May 1998. Fuzzy regulators and fuzzy observers: relaxed stability conditions and lmi-based designs. IEEE Transactions on Fuzzy Systems 6 (2), 250-265. https://doi.org/10.1109/91.66902

Radio monitoring of NGC 7469: Late time radio evolution of SN 2000ft and the circumnuclear starburst in NGC 7469

We present the results of an eight-year long monitoring of the radio emission from the Luminous Infrared Galaxy (LIRG) NGC 7469, using 8.4 GHz Very Large Array (VLA) observations at 0.3'' resolution. Our monitoring shows that the late time evolution of the radio supernova SN 2000ft follows a decline very similar to that displayed at earlier times of its optically thin phase. The late time radio emission of SN 2000ft is therefore still being powered by its interaction with the presupernova stellar wind, and not with the interstellar medium (ISM). Indeed, the ram pressure of the presupernova wind is \rho_w v_w^2 \approx 7.6E-9 dyn/cm^2, at a supernova age of approximately 2127 days, which is significantly larger than the expected pressure of the ISM around SN 2000ft. At this age, the SN shock has reached a distance r_{sh \approx 0.06 pc, and our observations are probing the interaction of the SN with dense material that was ejected by the presupernova star about 5820 years prior to its explosion. From our VLA monitoring, we estimate that the swept-up mass by the supernova shock after about six years of expansion is \approx 0.29 M_sun, assuming an average expansion speed of the supernova of 10000 km/s. We also searched for recently exploded core-collapse supernovae in our VLA images. Apart from SN 2000ft (S_\nu \approx 1760 microJy at its peak, corresponding to 1.1E28 erg/s/Hz, we found no evidence for any other radio supernova (RSN) more luminous than \approx 6.0E26 erg/s/Hz, which suggests that no other Type IIn SN has exploded since 2000 in the circumnuclear starburst of NGC 7469.Comment: 10 pages, 5 figures, accepted for publication in MNRA

The Spatial Extent of (U)LIRGs in the mid-Infrared I: The Continuum Emission

We present an analysis of the extended mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey (GOALS) sample based on 5-15um low resolution spectra obtained with the IRS on Spitzer. We calculate the fraction of extended emission as a function of wavelength for the galaxies in the sample, FEE_lambda. We can identify 3 general types of FEE_lambda: one where it is constant, one where features due to emission lines and PAHs appear more extended than the continuum, and a third which is characteristic of sources with deep silicate absorption at 9.7um. More than 30% of the galaxies have a median FEE_lambda larger than 0.5 implying that at least half of their MIR emission is extended. Luminous Infrared Galaxies (LIRGs) display a wide range of FEE in their warm dust continuum (0<=FEE_13.2um<=0.85). The large values of FEE_13.2um that we find in many LIRGs suggest that their extended MIR continuum emission originates in scales up to 10kpc. The mean size of the LIRG cores at 13.2um is 2.6kpc. However, once the LIR of the systems reaches the threshold of ~10^11.8Lsun, all sources become clearly more compact, with FEE_13.2um<=0.2, and their cores are unresolved. Our estimated upper limit for the core size of ULIRGs is less than 1.5kpc. The analysis indicates that the compactness of systems with LIR>~10^11.25Lsun strongly increases in those classified as mergers in their final stage of interaction. The FEE_13.2um is also related to the contribution of an active galactic nucleus (AGN) to the MIR. Galaxies which are more AGN-dominated are less extended, independently of their LIR. We finally find that the extent of the MIR continuum emission is correlated with the far-IR IRAS log(f_60um/f_100um) color. This enables us to place a lower limit to the area in a galaxy from where the cold dust emission may originate, a prediction which can be tested soon with the Herschel Space Telescope.Comment: 18 pages, 8 figures, accepted for publication in Ap

Impact of particles on the Planck HFI detectors: Ground-based measurements and physical interpretation

The Planck High Frequency Instrument (HFI) surveyed the sky continuously from August 2009 to January 2012. Its noise and sensitivity performance were excellent, but the rate of cosmic ray impacts on the HFI detectors was unexpectedly high. Furthermore, collisions of cosmic rays with the focal plane produced transient signals in the data (glitches) with a wide range of characteristics. A study of cosmic ray impacts on the HFI detector modules has been undertaken to categorize and characterize the glitches, to correct the HFI time-ordered data, and understand the residual effects on Planck maps and data products. This paper presents an evaluation of the physical origins of glitches observed by the HFI detectors. In order to better understand the glitches observed by HFI in flight, several ground-based experiments were conducted with flight-spare HFI bolometer modules. The experiments were conducted between 2010 and 2013 with HFI test bolometers in different configurations using varying particles and impact energies. The bolometer modules were exposed to 23 MeV protons from the Orsay IPN TANDEM accelerator, and to $^{241}$Am and $^{244}$Cm $\alpha$-particle and $^{55}$Fe radioactive X-ray sources. The calibration data from the HFI ground-based preflight tests were used to further characterize the glitches and compare glitch rates with statistical expectations under laboratory conditions. Test results provide strong evidence that the dominant family of glitches observed in flight are due to cosmic ray absorption by the silicon die substrate on which the HFI detectors reside. Glitch energy is propagated to the thermistor by ballistic phonons, while there is also a thermal diffusion contribution. The implications of these results for future satellite missions, especially those in the far-infrared to sub-millimetre and millimetre regions of the electromagnetic spectrum, are discussed.Comment: 11 pages, 13 figure

Radon and material radiopurity assessment for the NEXT double beta decay experiment

The Neutrino Experiment with a Xenon TPC (NEXT), intended to investigate the neutrinoless double beta decay using a high-pressure xenon gas TPC filled with Xe enriched in 136Xe at the Canfranc Underground Laboratory in Spain, requires ultra-low background conditions demanding an exhaustive control of material radiopurity and environmental radon levels. An extensive material screening process is underway for several years based mainly on gamma-ray spectroscopy using ultra-low background germanium detectors in Canfranc but also on mass spectrometry techniques like GDMS and ICPMS. Components from shielding, pressure vessel, electroluminescence and high voltage elements and energy and tracking readout planes have been analyzed, helping in the final design of the experiment and in the construction of the background model. The latest measurements carried out will be presented and the implication on NEXT of their results will be discussed. The commissioning of the NEW detector, as a first step towards NEXT, has started in Canfranc; in-situ measurements of airborne radon levels were taken there to optimize the system for radon mitigation and will be shown too.Comment: Proceedings of the Low Radioactivity Techniques 2015 workshop (LRT2015), Seattle, March 201

NEXT-100 Technical Design Report (TDR). Executive Summary

In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (bbonu) in Xe-136 at the Laboratorio Subterraneo de Canfranc (LSC), in Spain. The document formalizes the design presented in our Conceptual Design Report (CDR): an electroluminescence time projection chamber, with separate readout planes for calorimetry and tracking, located, respectively, behind cathode and anode. The detector is designed to hold a maximum of about 150 kg of xenon at 15 bar, or 100 kg at 10 bar. This option builds in the capability to increase the total isotope mass by 50% while keeping the operating pressure at a manageable level. The readout plane performing the energy measurement is composed of Hamamatsu R11410-10 photomultipliers, specially designed for operation in low-background, xenon-based detectors. Each individual PMT will be isolated from the gas by an individual, pressure resistant enclosure and will be coupled to the sensitive volume through a sapphire window. The tracking plane consists in an array of Hamamatsu S10362-11-050P MPPCs used as tracking pixels. They will be arranged in square boards holding 64 sensors (8 times8) with a 1-cm pitch. The inner walls of the TPC, the sapphire windows and the boards holding the MPPCs will be coated with tetraphenyl butadiene (TPB), a wavelength shifter, to improve the light collection.Comment: 32 pages, 22 figures, 5 table

Development and validation of a questionnaire to evaluate lifestyle-related behaviors in elementary school children

Background The SI! Program promotes cardiovascular health through a multilevel school-based intervention on four lifestyle-related components: diet, physical activity, understanding the body and heart, and management of emotions. We report here the development and validation of the KAH (knowledge, attitudes and habits)-questionnaire adapted for elementary school children (6-7 years old) as a tool for the forthcoming evaluation of the SI! Program, where the KAH scoring will be the primary outcome. The efficacy of such an intervention will be based on the improvements in children's KAH towards a healthy lifestyle. Methods The questionnaire validation process started with a pool of items proposed by the pedagogical team who developed the SI! Program for elementary school. The questionnaire was finalized by decreasing the number of items from 155 to 48 using expert panels and statistical tests on the responses from 384 children (ages 6-7). A team of specialized psychologists administered the questionnaire at schools providing standard directions for the final administration. The internal consistency was assessed using Cronbach's α coefficients. Reliability was measured through the split-half method, and problematic items were detected applying the item response theory. Analysis of variance and Tukey's test of additivity were used for multiple comparisons. Results The final KAH-questionnaire for elementary school children should be administered to children individually by trained staff. The 48 items-questionnaire is divided evenly between the 4 components of the intervention, with an overall Cronbach's α = 0.791 (α = 0.526 for diet, α = 0.537 for physical activity, α = 0.523 for human body and heart, and α = 0.537 for management of emotions). Conclusions The KAH-questionnaire is a reliable instrument to assess the efficacy of the SI! Program on instilling healthy lifestyle-related behaviors in elementary school children