J. S. da Rocha Neto

Non-Invasive Fast Detection of Internal Fouling Layers in Tubes and Ducts by Acoustic Vibration Analysis

The easy detection of fouling in duct systems is a persistent problem and remains a relevant demand for the chemical, oil, food, and pharmaceutical industries. The fouling process is the slow unwanted layer deposition of heavy organic and other dissolved solid materials out of transported fluids onto inner wall surfaces over an extended period of time. This work presents preliminary research results of vibrational hammer excitation for easy-to-use external non-invasive nondestructive fouling detection in pipelines and other large-scale duct systems. The main goal is the localization of inner pipe-layer formation and thickness estimation of the adsorbed material. Data were taken from the vibration variation in the presence of an inner pipe fouling layer using acoustic microphone detection. The experimental setup, achievable sensitivities, and limitations of the method are outlined.

Development of Circuits for Excitation and Reception in Ultrasonic Transducers for Generation of Guided Waves in Hollow Cylinders for Fouling Detection

This work presents circuits that are developed to excite ultrasonic transducers transmitters and to receive the coming signals of ultrasonic transducers receivers, via hollow cylinder, converted into guided waves so that this system (transmitter and receiver) can be used for fouling detection. The fouling is a problem that has been present in the chemical, petroleum, food and pharmaceutical industries. It consists of the deposition of heavy organic materials and other dissolved solids or in suspension in fluid transport system. The ultrasonic guided waves present specific characteristics and have demonstrated good results in detection of flaws in piping. The circuits are presented and experimental results discussed

Propagation measurements and modeling for monitoring and tracking in animal husbandry applications

Transmission loss measurements using IEEE 802.15.4 technology are reported in an outdoor environment for application to monitoring and tracking of small ruminants. The simplest possible propagation model is shown to reflect the general features of the measured propagation data. Its absolute accuracy, however, is probably inadequate for use in a location algorithm based on model inversion without optimization of its parameters. Model calibration to reflect inter-site variation of the propagation environment is suggested as a possible way of realizing a location system with useful accuracy and adequate portability.

Automation of an anaerobic-aerobic wastewater treatment process

In this paper, the treatment capacity and effluent quality of an anaerobic-aerobic sewage treatment system composed of a upflow anaerobic sludge blanket unit in series with a sequencing batch reactor (SBR) is evaluated. The aerobic part of the system (the SBR) is automated and the concentration of dissolved oxygen is used as a control parameter for the aeration period.

Monitoring of temperature using smart sensors based on CAN architecture

In this work is presented the implementation of smart sensors for monitoring temperature and for communicating among them self using the protocol CAN (controller area network). A smart sensor has the capacity to make decisions based on data and command received. These decisions can include the control of an actuator, the sending of information for a controller in communication to other smart sensor that can carry out a wished function. CAN is a protocol of serial communication that allows the control of systems distributed in real time with high level of safety. This protocol was developed in the nineteen eighties in order to decentralize vehicle control systems because their characteristics CAN are being used currently in several areas.

Partial Discharge Location using Unsynchronized Radiometer Network for Condition Monitoring in HV Substations - A Proposed Approach

A location estimation system for online Partial Discharge (PD) detection is proposed as a low-cost approach to real-time condition monitoring, asset management and operation optimization in future smart grid. Some early progress in the development of subsystems (specifically the antenna, radiometer device, PD emulator and PD generator) for a proof-of-principle prototype system is described. The proposed PD Wireless Sensor Network (WSN) uses a novel approach to PD location which obviates the need for synchronization between sensors thereby improving scalability.

Fouling Detection based on Vibration Analysis with the Hammer Impact Test

Fouling detection is a persistent and relevant problem for the chemical, oil, food and pharmaceutical industries. The fouling process is the slow, unwanted layer deposition of heavy organic and other dissolved solid material out of transported fluids or suspensions onto inner wall surfaces in fluid transport system over an extended period of time. This work presents preliminary research results of vibrational hammer excitation for easy to use external noninvasive, non-destructive fouling detection in pipelines. The main goal is the detection of inner pipe layer formation, and thickness estimation of the adsorbed material. Data were taken from the temporal variation, and distortion / down shift of the natural vibrational pipe frequency spectrum in presence of an inner pipe fouling layer. The experimental set-up, sensitivity, observable frequency shift and spatial resolution of the method are outlined.

Estimation of dissolved oxygen dynamics for sequencing batch aerobic reactors

In this paper a wastewater treatment pilot plant, which consists of an upflow anaerobic sludge blanket reactor (UASB) in series with a batch reactor operated in aerobic conditions is under study. Both reactors are based in the activated sludge process. The work is focused on the estimation of the dissolved oxygen dynamics of the aerobic reactor: the oxygen transfer function and the respiration rate are estimated first in nonrecursive mode in the beginning of the batch and then, the respiration rate is estimated in recursive mode. Simulation and experimental estimates are performed.

Development of a partial discharge emulator for calibration of a radiometric PD detection system

A purely electronic partial discharge emulator for use in a location estimation algorithm for online partial discharge detection is proposed as a low-cost approach to real-time condition monitoring, asset management and operation optimization in future smart grid. Some early progress in the development of subsystems (specifically the radiometer antenna and PD emulator) for a proof-of-principle prototype system are described.

Sensors Characterization and Control of Measurement Systems with Thermoresistive Sensors using Feedback Linearization

This paper proposes the use of feedback linearization for the characterization of thermoresistive sensors and the control of measurement systems based on thermoresistive sensor with constant temperature. Regarding sensors characterization, the main advantage of this technique is the fact that the set of parameters for a given device can be determined by a single experiment. Concerning measurement systems based on thermoresitive sensors, this technique prevents linear controllers from losing performance due to changes the operation point. Experimental results of temperature control for a system linearized by feedback are presented and its performance is compared to that of a system without linearization.