Effect of Tidal Cycling Rate on the Distribution and Abundance of Nitrogen-Oxidizing Bacteria in a Bench-Scale Fill-and-Drain Bioreactor

Most domestic wastewater can be effectively treated for secondary uses by engineered biological systems. These systems rely on microbial activity to reduce nitrogen (N) content of the reclaimed water. Such systems often employ a tidal-flow process to minimize space requirements for the coupling of aerobic and anaerobic metabolic processes. In this study, laboratory-scale tidal-flow treatment systems were studied to determine how the frequency and duration of tidal cycling may impact reactor performance. Fluorescent in situ hybridization and epifluorescence microscopy were used to enumerate the key functional groups of bacteria responsible for nitrification and anaerobic ammonium oxidation (anammox), and N-removal efficiency was calculated via a mass-balance approach. When water was cycled (i.e., reactors were filled and drained) at high frequencies (16–24 cycles day−1), nitrate accumulated in the columns—presumably due to inadequate periods of anoxia that limited denitrification. At lower frequencies, such as 4 cycles day−1, nearly complete N removal was achieved (80–90%). These fill-and-drain systems enriched heavily for nitrifiers, with relatively few anammox-capable organisms. The microbial community produced was robust, surviving well through short (up to 3 h) anaerobic periods and frequent system-wide perturbation

A Comparison between Position-Based and Image-Based Dynamic Visual Servoings in the Control of a Translating Parallel Manipulator

Two different visual servoing controls have been developed to govern a translating parallel manipulator with an eye-in-hand configuration, That is, a position-based and an image-based controller. The robot must be able to reach and grasp a target randomly positioned in the workspace; the control must be adaptive to compensate motions of the target in the 3D space. The trajectory planning strategy ensures the continuity of the velocity vector for both PBVS and IBVS controls, whereas a replanning event is needed. A comparison between the two approaches is given in terms of accuracy, fastness, and stability in relation to the robot peculiar characteristics

Luenberger observers for switching discrete-time linear systems

State estimation is considered for a class of switching discrete-time linear systems. The switching is assumed to be unknown among the various system modes associated with different known matrices. The proposed scheme relies on the combination of the estimation of the system mode with the application of a Luenberger-like observer whose gain is a function of the estimated mode. In the absence of noises, the estimate of the mode can be chosen among the ones that are consistent with the measurements and the stability of the estimation error is ensured under suitable conditions on the observer gains. Such conditions can be expressed by means of linear matrix inequalities (LMIs). The presence of bounded disturbances is also taken explicitly into consideration. In this situation, a novel method based on a minimum-distance criterion is proposed in order to estimate the system mode. Also in this case the error of the resulting estimator is proved to be exponentially bounded

Dynamic modelling of a 3-CPU parallel robot via screw theory

The article describes the dynamic modelling of I.Ca.Ro., a novel Cartesian parallel robot recently designed and prototyped by the robotics research group of the Polytechnic University of Marche. By means of screw theory and virtual work principle, a computationally efficient model has been built, with the final aim of realising advanced model based controllers. Then a dynamic analysis has been performed in order to point out possible model simplifications that could lead to a more efficient run time implementation

Dynamic modelling of a 3-CPU parallel robot via screw theory

Abstract. The article describes the dynamic modelling of I.Ca.Ro., a novel Cartesian parallel robot recently designed and prototyped by the robotics research group of the Polytechnic University of Marche. By means of screw theory and virtual work principle, a computationally efficient model has been built, with the final aim of realising advanced model based controllers. Then a dynamic analysis has been performed in order to point out possible model simplifications that could lead to a more efficient run time implementation

Symmetric Promise Constraint Satisfaction Problems: Beyond the Boolean Case

The Promise Constraint Satisfaction Problem (PCSP) is a recently introduced vast generalization of the Constraint Satisfaction Problem (CSP). We investigate the computational complexity of a class of PCSPs beyond the most studied cases - approximation variants of satisfiability and graph coloring problems. We give an almost complete classification for the class of PCSPs of the form: given a 3-uniform hypergraph that has an admissible 2-coloring, find an admissible 3-coloring, where admissibility is given by a ternary symmetric relation. The only PCSP of this sort whose complexity is left open in this work is a natural hypergraph coloring problem, where admissibility is given by the relation "if two colors are equal, then the remaining one is higher.

La régulation du comportement d’exercice et les raisons de l’activité physique: la validation italienne des questionnaires BREQ et MPAM-R

Based on self-determination theory, the purpose of the present study was to provide the first Italian validation of two different instrument to assess the exercise behaviour: the Mullan et al.'s (1997) BREQ which measures external, introjected, identified and intrinsic forms of regulation and Ryan et al.'s (1997) MPAM-R, which assesses five distinct motives for physical activity (appearance, health and fitness, social, competence, and enjoyment). Confirmatory factor analysis conducted on data collected from 1995 students attending three different secondary schools empirically supported respectively the four-factor structure of behavioural regulation and the five-factor structure of motives for physical activity, supporting convergent and discriminant validity of both scales. Furthermore, multi-group confirmatory factor analysis showed the invariance of the factor structures, structural parameters and correlations of the two scales across gender. Criterion-related validity of the scales also received partial empirical support. Finally, the factor structure of behavioural regulation and motives for physical activity was empirically supported when both constructs were included in a single measurement model.Sur la base de la théorie de l’auto-détermination, le but de cette étude est de proposer la validation de deux instruments différents pour l’évaluation du comportement d’exercice : le BREQ de Mullan et a. (1997), qui mesure les formes externe, introjectée, identifiée, et intrinsèque de la régulation, et le MPAM-R de Ryan et al. (1997), qui évalue cinq raisons distingués de l’activité physique (apparence, santé et forme physique, sociale, compétence, et amusement). L’analyse factorielle confirmatoire, conduite auprès de 1995 étudiants inscrits à trois lycées différents, a soutenu empiriquement la structure à quatre facteurs de la régulation du comportement ainsi que la structure à cinq facteurs des raisons de l’activité physique. De plus, l’analyse confirmatoire multi-groupe a montré l’invariance des structures factorielles, des paramètres structuraux, et des corrélations des deux échelles en relation au genre sexuel. La validité critériée des échelles a aussi reçu un soutien empirique partiel. Enfin, la structure factorielle de la régulation du comportement et des raisons de l’activité physique a été soutenue empiriquement lorsque les deux construits ont été inclus dans le même modèle de mesure

Multi-mode TES bolometer optimization for the LSPE-SWIPE instrument

In this paper we explore the possibility of using transition edge sensor (TES) detectors in multi-mode configuration in the focal plane of the Short Wavelength Instrument for the Polarization Explorer (SWIPE) of the balloon-borne polarimeter Large Scale Polarization Explorer (LSPE) for the Cosmic Microwave Background (CMB) polarization. This study is motivated by the fact that maximizing the sensitivity of TES bolometers, under the augmented background due to the multi-mode design, requires a non trivial choice of detector parameters. We evaluate the best parameter combination taking into account scanning strategy, noise constraints, saturation power and operating temperature of the cryostat during the flight.Comment: in Journal of Low Temperature Physics, 05 January 201

COSMOSOMAS Observations of the CMB and Galactic Foregrounds at 11 GHz: Evidence for anomalous microwave emission at high Galactic Latitude

We present observations with the new 11 GHz radiometer of the COSMOSOMAS experiment at the Teide Observatory (Tenerife). The sky region between 0 deg <= RA <= 360 deg and 26 deg <= DEC 49 deg (ca. 6500 square degrees) was observed with an angular resolution of 0.9 deg. Two orthogonal independent channels in the receiving system measured total power signals from linear polarizations with a 2 GHz bandwidth. Maps with an average sensitivity of 50 microK per beam have been obtained for each channel. At high Galactic latitude (|b|>30deg) the 11 GHz data are found to contain the expected cosmic microwave background as well as extragalactic radiosources, galactic synchrotron and free-free emission, and a dust-correlated component which is very likely of galactic origin. At the angular scales allowed by the window function of the experiment, the dust-correlated component presents an amplitude \Delta T aprox. 9-13 microK while the CMB signal is of order 27 microK. The spectral behaviour of the dust-correlated signal is examined in the light of previous COSMOSOMAS data at 13-17 GHz and WMAP data at 22-94 GHz in the same sky region. We detect a flattening in the spectral index of this signal below 20 GHz which rules out synchrotron radiation as being responsible for the emission. This anomalous dust emission can be described by a combination of free-free emission and spinning dust models with a flux density peaking around 20 GHz.Comment: 17 pages, 10 tables, 20 figures. Details on the COSMOSOMAS experiment can be found at http://www.iac.es/project/cmb/cosmosomas

Emotional labor as emotional regulation: Italian adaptation and longitudinal validation of the scale among undergraduate nursing students

Aim: The aim of the present study is to perform a longitudinal Italian validation of the scale and to adapt it to the nursing education contest. Background: Research on emotional labor has shown that the roles played by surface acting and deep acting are still uncertain. To overcome this gap, scholars suggest observing emotional labor through the lens of the emotional regulation theory. Andela and her colleagues developed a fine grained instrument, which differentiates attentional deployment, cognitive re-evaluation and expressive suppression, emotional amplification and emotional dissonance. Design. To fulfill our aim, a longitudinal study was performed in an Italian University. Method. The adapted scale was administered to 168 nursing students across the three years of attendance in the course. Results. Our results confirm the five-factor structure, and the instrument shows good psychometrical properties. Conclusion. Having shown satisfactory psychometric properties, this scale can be considered a useful instrument to assess those emotional elements of clinical practice, which are important for the assurance of education quality to the under graduated nursing students