Alex Krummenauer

Dr. Alex Krummenauer

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2019 in Journal of Environmental Chemical Engineering
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Journal Article
Closed access
FHFernando Hamerski
Fernando Hamerski
AKAlex Krummenauer
Alex Krummenauer
ANDREA MOURA BERNARDESANDREA MOURA BERNARDES
ANDREA MOURA BERNARDES
HVHUGO MARCELO VEIT
HUGO MARCELO VEIT

24 March 2023 in Metrology
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Journal Article
Open access
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AKAlex Krummenauer
Alex Krummenauer
VGVictor Emmanuel de Oliveira Gomes
Victor Emmanuel de Oliveira Gomes
VNVitor Camargo Nardelli
Vitor Camargo Nardelli
The need to control the real-time location of assets is increasingly relevant worldwide. The Ultra-wideband (UWB) technology is an IoT solution for real-time locating systems (RTLS). The location of the asset is obtained by the signal exchange between a wireless tag (asset) and fixed anchors. The tag interacts with the fixed anchors, defining its position through the distances obtained by trilateration. This data is sent to the server through the gateway. It is well-known that this process has several sources of errors. However, the measurement uncertainty assessment of UWB technology is an important topic regarding its scope of use. This paper presents a task-specific measurement uncertainty evaluation for the UWB positioning system, according to the ISO GUM. It aims to propose a method to support decision-making regarding the possible uses of UWB technology. The position provided by the UWB is compared with reference points using Cartesian coordinates that are measured with a total station, providing metrological reliability. Using the information from the estimated uncertainty, one can define the minimum tolerance interval associated with UWB technology for a given use. A case study demonstrates the method.

1 January 2019 in Materials Research
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Journal Article
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ESEduardo Luis Schneider
Eduardo Luis Schneider
FHFernando Hamerski
Fernando Hamerski
HVHUGO MARCELO VEIT
HUGO MARCELO VEIT
AKAlex Krummenauer
Alex Krummenauer
MCMarcelo Pilotto Cenci
Marcelo Pilotto Cenci
AVAlexandre Silva de Vargas
Alexandre Silva de Vargas
The aim of this work was to evaluate mass loss in each stage of the recycling process for metal recovery from PCBs of controllers and temperature indicators of cold chambers. The stages of process consists of grinding, particle size classification, magnetic and electrostatic separation. It was analyzed 13 kg of PCBs. These PCBs were crushed and ground. The ground material were subjected to magnetic and electrostatic separator. The losses in the comminution stages were 12.69 % and are lower than those found in other related works that used mixtures of different types of PCBs, whereas in this work only one model plates were analyzed. 27.2 % absolute mass loss we reached out after particle size separation with Tyler Series with 1 mm sieve presents the higher mass losses in the whole process and this fraction was not processed as it results in PCBs powder dust that interferes negatively in the electrostatic separation. Comparing the losses in the stages of shredding of PCBs employed in temperature controllers with other studies involving PCBs from the automotive industry and from computers and cell phones, is remarkable that this type of board presents significantly greater potential to be processed for recovery of its materials.

12 April 2024 in Metrology
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Journal Article
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AKAlex Krummenauer
Alex Krummenauer
Douglas BergamoDouglas Bergamo
Douglas Bergamo
RSRoberto Serpa Soares
Roberto Serpa Soares
VGVictor Emmanuel de Oliveira Gomes
Victor Emmanuel de Oliveira Gomes
VNVitor Camargo Nardelli
Vitor Camargo Nardelli
The dimensional accuracy of a laser scanner has been extensively evaluated using various measurement methods and diverse reference standards. This study specifically focuses on two key considerations. Firstly, it assesses the dimensional accuracy of the laser scanner by employing another laser scanner, a handheld scanner, as the reference measurement method. Secondly, the study involves the use of three spheres fixed on each wall in both coplanar and non-coplanar positions within a laboratory room at SENAI ISI-SIM. The primary objective is to determine the dimensional accuracy between the centers of the coplanar and non-coplanar spheres up to 10 m. The comparison includes measurement uncertainties, as per ISO GUM standards, obtained using the laser scanner in a laboratory setting with controlled temperature and humidity. Analyzing non-coplanar dimensional accuracy enhances our understanding of the metrological performance of the laser scanner, particularly when assessing the dimensions of objects positioned randomly within a scanning scene.

30 September 2020 in Studia Universitatis Babeș-Bolyai Chemia
Verified
Journal Article
Open access
Vitor Bonamigo MoreiraVitor Bonamigo Moreira
Vitor Bonamigo Moreira
AKAlex Krummenauer
Alex Krummenauer
JFJane Zoppas Ferreira
Jane Zoppas Ferreira
HVHUGO MARCELO VEIT
HUGO MARCELO VEIT
Elaine ArmelinElaine Armelin
Elaine Armelin
AMAlvaro Meneguzzi
Alvaro Meneguzzi
The current standards for evaluating corrosion during salt spray tests rely on the visual analysis of the specimens, and this may be a limitation when higher resolution quantitative outputs are desired. In this work, computational image analysis was used to measure the area affected by corrosion during salt spray tests with aluminum alloy, copper, carbon steel and galvanized steel plates. The software ImageJ was used to select and measure the corroded areas differentiating the corrosion products from the metals uncorroded surfaces according to their different colors. With ten measurements for each selected exposure time, a 95 % confidence interval was calculated for each material and time of exposure, giving an indication of the precision of the estimated corroded area. These data were compared with a visual inspection carried out by an experienced technician. The results indicate that computational image analysis may be a powerful tool to obtain higher resolution in the results interpretation in comparison with the standard visual analysis.

20 March 2018 in Journal of Physics: Conference Series
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Conference Paper
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AKAlex Krummenauer
Alex Krummenauer
HVHUGO MARCELO VEIT
HUGO MARCELO VEIT
JZJ Zoppas-Ferreira
J Zoppas-Ferreira
Comparison with reference method is one of the necessary requirements for the validation of non-standard methods. This comparison was made using the experiment planning technique with two-way ANOVA. In ANOVA, the results obtained using the EDXRF method, to be validated, were compared with the results obtained using the ASTM E572-13 standard test method. Fisher's tests (F-test) were used to comparative study between of the elements: molybdenum, niobium, copper, nickel, manganese, chromium and vanadium. All F-tests of the elements indicate that the null hypothesis (Ho) has not been rejected. As a result, there is no significant difference between the methods compared. Therefore, according to this study, it is concluded that the EDXRF method was approved in this method comparison requirement.