Effect of Ozone on Filamentous Bulking in a Laboratory Scale Activated Sludge Reactor Using Respirometry and INT-Dehydrogenase Activity

Filamentous bulking can be controlled by the addition of oxidant chemical agents such as ozone. To evaluate the ozone effect on activated sludge from a laboratory scale reactor, different techniques were applied: Settleability test, respirometry (oxygen uptake rate), and the INT-dehydrogenase activity test carried out both by spectrophotometry (DHAa) and image analysis (DHAi). In activated sludge, the respirometric technique and the spectrophotometric DHAa quantified ozone action on the total respiratory activity of flocs; in contrast, the image DHAi test was applied to evaluate the specific action of ozone on filamentous microorganisms. The conditions for application of the INT-dehydrogenase activity test were standardized using pure cultures of a filamentous microorganism (Sphaerotilus natans) and a floc-forming bacterium (Acinetobacter anitratus). For activated sludge with filamentous bulking, ozone doses and treatment times necessary to improve settleability were established. Ozone dose levels and contact times influence the viability of bacteria in flocs and filaments and the finding of appropriate parameters to preserve floc viability and, at the same time, inhibiting filaments is essential to filament control by ozonation.     

A Proposal to Extend the OpenMP Tasking Model with Dependent Tasks

Tasking in OpenMP 3.0 has been conceived to handle the dynamic generation of unstructured parallelism. New directives have been added allowing the user to identify units of independent work (tasks) and to define points to wait for the completion of tasks (task barriers). In this document we propose extensions to allow the runtime detection of dependencies between generated tasks, broading the range of applications that can benefit from tasking or improving the performance when load balancing or locality are critical issues for performance. The proposed extensions are evaluated on a SGI Altix multiprocessor architecture using a couple of small applications and a prototype runtime system implementation.     

Design and implementation of mechanical resonators for optimized inertial electromagnetic microgenerators

This work describes the design and implementation of an electromagnetic inertial microgenerator for energy scavenging from ambient vibrations. The structure of the device is based in a mechanical resonator formed by a permanent magnet (inertial mass) mounted on a polymeric membrane, in combination with a fixed micromachined coil. ANSYS simulations are carried out to investigate the influence of the resonator geometry on the resonant frequency and on the parasitic damping, and to analyze the optimum geometry of the coil for optimization of the electromagnetic coupling in the devices. Generator prototypes have been fabricated with a modular manufacturing process in which the electromagnetic converter and the mechanical resonator are manufactured separately, diced and then assembled. The experimental results show the ability of these devices to generate power levels in the range of 50 μW with output voltages in the range of hundreds of mV. The parasitic damping of the resonator structures is estimated from the fitting of the experimental data, and suggests the existence of an intrinsic limitation of the polymers related to spring stiffening effects at large excitation amplitudes. The comparison of the simulations and the experimental results indicate that further optimizations of this parameter and of the coil series resistance would allow increasing the generated power in more than one order of magnitude.     

Complexity classes in models of cellular computing with membranes

In this paper we introduce four complexity classes for cellularcomputing systems with membranes: the first and the second ones containall decision problems solvable in polynomial time by a family ofdeterministic P systems, without and with an input membrane,respectively; the third and fourth classes contain all decision problemssolvable in polynomial time by a family of non-deterministic P systems,without and with an input membrane, respectively. We illustrate theusefulness of these classes by solving two NP–completeproblems, namely HPP and SAT, in both variants of Psystems.     

An Environment for Modeling and Design of Geographic Applications

This paper presents UAPÉ—a computational environment for modeling and designing environmental geographic applications. UAPÉ is aimed at end-users who are experts in their application domain, but who do not have adequate background in software engineering or database design, and thus are unable to take full advantage of available GIS tools. Its goal is to reduce the impedance between the end-users view of the world and its implementation in Geographic Information Systems. The environment has been designed and implemented so that it can be considered as an auxiliary layer to be coupled to a GIS. The major features of this layer are: it has an open architecture, being independent of a specific GIS, so that it can be coupled to different systems; it allows the user to deal only with the conceptual view of the geographic reality, abstracting the implementation details; it supports a geographic application design methodology, fully integrated with a high-level semantic data model, so there is no impedance mismatch between application design and data modeling.     

OBCAS: an agent-based system and ontology for mobile context aware interactions

Society is changing and technological advances provide mechanisms to facilitate the development of a large number of tasks in technical, humanities, health and social areas. Nowadays, application of the improvement of people’s quality of life is generating significant interest, giving birth to systems oriented to the supervision, care and help for people in the development of their daily affairs. Thus, we may assume that its application to the supervision of a specific group of people can improve the quality of life for many people. OBCAS implements a monitoring service through mobile devices capable of providing enough information for an intelligent system. The multi-agent component provides the intelligence for the system, allowing it to run the appropriate services by adjusting them to the user’s profile and preferences. AGATHA is an application based on OBCAS that provides an alarm service during a supervision process. AGATHA has been tested on the supervision of elderly and victims of gender violence, and the result shown in this paper has been satisfactory.     

Updating a cautionary tale of masked priming: Reply to Klapp (2005).

The commentary by S. T. Klapp (see record 2005-09704-010) on our recent article (A. Lleras & J. T. Enns, [see record 2004-21166-001]) proposes that the empirical finding of negative compatibility in masked priming be attributed to 2 distinct theoretical constructs: (a) perceptual priming through object updating, as described in our article, and (b) nonperceptual priming based on inhibited unconscious response tendencies. The authors argue that this 2nd construct is not supported by either the new data the authors report or the extant literature. Instead, the negative compatibility effect in masked priming is influenced by perceptual interactions among stimuli that appear in the same spatial location, and the authors believe it is this process that deserves further systematic study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A stable MPC with zone control

Several MPC applications implement a control strategy in which some of the system outputs are controlled within specified ranges or zones, rather than at fixed set points [J.M. Maciejowski, Predictive Control with Constraints, Prentice Hall, New Jersey, 2002]. This means that these outputs will be treated as controlled variables only when the predicted future values lie outside the boundary of their corresponding zones. The zone control is usually implemented by selecting an appropriate weighting matrix for the output error in the control cost function. When an output prediction is inside its zone, the corresponding weight is zeroed, so that the controller ignores this output. When the output prediction lies outside the zone, the error weight is made equal to a specified value and the distance between the output prediction and the boundary of the zone is minimized. The main problem of this approach, as long as stability of the closed loop is concerned, is that each time an output is switched from the status of non-controlled to the status of controlled, or vice versa, a different linear controller is activated. Thus, throughout the continuous operation of the process, the control system keeps switching from one controller to another. Even if a stabilizing control law is developed for each of the control configurations, switching among stable controllers not necessarily produces a stable closed loop system.Here, a stable MPC is developed for the zone control of open-loop stable systems. Focusing on the practical application of the proposed controller, it is assumed that in the control structure of the process system there is an upper optimization layer that defines optimal targets to the system inputs. The performance of the proposed strategy is illustrated by simulation of a subsystem of an industrial FCC system.     

On an operational matrix method based on generalized Bernoulli polynomials of level <Emphasis Type="Italic">m</Emphasis>

An operational matrix method based on generalized Bernoulli polynomials of level m is introduced and analyzed in order to obtain numerical solutions of initial value problems. The most innovative component of our method comes, essentially, from the introduction of the generalized Bernoulli polynomials of level m, which generalize the classical Bernoulli polynomials. Computational results demonstrate that such operational matrix method can lead to very ill-conditioned matrix equations.