Showing papers by "CHESF published in 2012"
TL;DR: Sample field results on one of the sensor systems show a direct correlation of the activity recorded by the system with the pollution level expected to occur near the corresponding monitoring point.
Abstract: This paper describes the design and development of a sensor system network for remote monitoring of the state of pollution on high-voltage insulators, its deployment among four states in Northeast Brazil and preliminary analysis of the data gathered by the system. Six monitoring units, each composed by leakage current, humidity, and temperature sensors, an electronic processing module, and a satellite-communication link, were built and installed on 230- and 500-kV transmission towers. Measured data are sent by the different systems via satellite to a database controlled by a web-based graphical user interface, incorporated into the supervision-management system of the electric utility company. Sample field results on one of the sensor systems, both for short- and long-term measurements, show a direct correlation of the activity recorded by the system with the pollution level expected to occur near the corresponding monitoring point.
37 citations
TL;DR: The genus Botryococcus comprises a group of cosmopolitan species of freshwater colonial green algae, some of which synthesize and accumulate an unusually high level of liquid hydrocarbons, which suggests the possibility of exploiting species from this group as renewable sources for jet fuel.
Abstract: The genus Botryococcus comprises a group of cosmopolitan species of freshwater colonial green algae, some of which synthesize and accumulate an unusually high level (15-76%) of liquid hydrocarbons. This characteristic suggests the possibility of exploiting species from this group as renewable sources for jet fuel. An oil-rich strain of Botryococcus (Trebouxiophyceae) was isolated from a freshwater pond in the state of Bahia, Brazil, and is presently maintained under standard conditions at the Culture Collection of the Institute of Biology, Federal University of Bahia. The taxonomic classification of the species was based on light microscopy (LM); and TEM and SEM were used to better characterize its features, which have never before been described at this level. The LM characterization included the size of the colonies (35.7-157 μm) and cells (8-10 × 5-9 μm) and their connection in sub-colonies by mucilaginous strands, as well as the presence of mucilaginous processes on the periphery of some of the colonies, with most of the cells included inside the colony. Reproduction occurred through divisions into two to four autospores. These features characterized the species as Botryococcus terribilis Komarek and Marvan. The TEM study showed, in addition to the presence of starch grains, pyrenoids that are penetrated by thick thylakoids. The pyrenoid bodies appear as electron-dense protein inclusions located in the chloroplast and surrounded by a starch sheath. These structures, which contain most if not all of the Ribulose-1,5-bisphosphate carboxylase oxygenase in several algal species that have been studied closely, are newly discovered for this species.
12 citations
TL;DR: In this paper, a model based on micro-computed tomography and scanning electron microscope data was proposed to explain the evolution of those large cracks in composite insulators, in order to explain why the cracks appear essentially perpendicular to the composite rod axis.
Abstract: Composite insulators aged in-service for almost 10 years at the transmission line of 230 kV, in an area where brittle fracture of a composite insulator occurred, were inspected by the micro-computed tomography, μ-CT, and by the scanning electron microscope, SEM. As a result, several cracks with different depths under pollutant scale and confined in silicone housing were detected by the μ-CT. Surface of silicone housing was observed by the SEM. Many randomly oriented cracks from micrometers size were observed. However, larger cracks detected and evaluated by the μ-CT appear essentially perpendicular to the composite rod axis. In order to explain the evolution of those large cracks in composite insulators, a model based on μ-CT and SEM data was proposed. [doi:10.2320/matertrans.I-M2012802]
4 citations
13 Dec 2012
TL;DR: This study set out to present a decision support system based on a multi-attribute p-median model and some hypotheses were assumed through the Multiattribute Utility Theory concept.
Abstract: Facility location is a theory developed to support decisions about where to place strategic resources with low mobility. Determining the best location for a back-up transformer is a relevant example. Thus, this study set out to present a decision support system based on a multi-attribute p-median model. Some hypotheses were assumed through the Multiattribute Utility Theory concept. The back-up transformer locations were indicated and analysed.
3 citations
28 May 2012
TL;DR: A protocol for the transmission of visual cues, represented by Augmented Reality elements, in collaborative applications, focuses on a client-server communication, where the client has the role to remotely supervise the activities, possibly sending interest points or instruction to the server.
Abstract: Inspection and maintenance of complex hardware equipment can have an elevated cost, due to the sophisticated training required for the technicians responsible for those tasks. The use of collaborative Augmented Reality can solve, or at least reduce, the cost of these activities. This paper proposes a protocol for the transmission of visual cues, represented by Augmented Reality elements, in collaborative applications. The protocol focuses on a client-server communication, where the client has the role to remotely supervise the activities, possibly sending interest points or instruction to the server. A prototype application was developed in order to demonstrate the advantages of a real application usage.
2 citations
Patent•
15 Aug 2012TL;DR: In this article, the authors present an efficient and inexpensive way to integrate equipment such as transformers, in any amounts, with different voltages and different specifications in the same parallelism logic.
Abstract: The present invention provides systems and methods for integration and for the regulation and parallelism among different models of voltage sources and/or high voltage energized gaps. In a preferred embodiment, the present invention provides an efficient and inexpensive way to integrate equipment such as transformers, in any amounts, with different voltages and different specifications in the same parallelism logic, meeting strict criteria and requirements.