Khrissy Medeiros

Dr. Khrissy Medeiros

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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29 October 2018 in Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles
Verified
Journal Article
Open access
KMKhrissy Medeiros
Khrissy Medeiros
EREduardo Queirós Rangel
Eduardo Queirós Rangel
ASAlexandre Ribeiro Sant’aNna
Alexandre Ribeiro Sant’aNna
DLDaniel Ramos Louzada
Daniel Ramos Louzada
CHCARLOS HALL
CARLOS HALL
JDJosé Roberto Moraes D’aLmeida
José Roberto Moraes D’aLmeida
A sample of polyvinylidene fluoride removed from a riser component was tested in laboratory to evaluate its electromechanical behavior. For this, an experimental setup was developed, after Fourier Transform Infrared Spectroscopy (FTIR) results have shown through the absorption bands, that this sample had a spectrum of the piezoelectric phase β. In order to identify if such sample would be able to respond electrically to the application of external mechanical excitation applied by a shaker, measurements were made of the induced voltages by piezoelectric effect, with varying accelerations and frequencies. The results indicated that the material, although it has not been processed for this purpose, responds electrically to the applied mechanical stimulus, demonstrating a good correlation between the measured signals and the accelerations.

23 August 2023 in Critical Reviews in Analytical Chemistry
Verified
Journal Article
Closed access
KMKhrissy Medeiros
Khrissy Medeiros
LCLivio Garcia da Costa
Livio Garcia da Costa
GMGabriela Knippelberg Bifano Manea
Gabriela Knippelberg Bifano Manea
RMRoberta de Moraes Maciel
Roberta de Moraes Maciel
ECEdnéia Caliman
Ednéia Caliman
Elcio Cruz de OliveiraElcio Cruz de Oliveira
Elcio Cruz de Oliveira
Sulfur-containing compounds are naturally found in crude oil, and they can be partially removed during the refining process. The wide use of fossil fuels has a significant contribution to sulfur emissions into the atmosphere, and Governments are striving to reduce the amount of the fuels by environmental regulations. The reduction of sulfur levels in diesel and other transportation fuels is beneficial from economic and environmental points, but meeting this standard represents a major operational and economic challenge for the oil and gas industry. Quantitative measurement of the sulfur amount must be taken along the oil refining chains guided by standards of measurement and recommended analytical methods such as various American Society for Testing and Materials methods (ASTM D2622, ASTM D5453, ASTM D7039, and ASTM D7220). Advancement in the refining processes and environmental regulations also require reliable measurements and well-defined criteria for compliance assessment. This work presented a brief review of the ASTM Standards used in the laboratories of the Brazilian oil and gas industry to determine the total sulfur content in fuels. We also presented an approach based on the reproducibility of the measurement methods and the guard band concept to evaluate the conformity statement.

9 February 2022 in Critical Reviews in Analytical Chemistry
Verified
Journal Article
Closed access
KMKhrissy Medeiros
Khrissy Medeiros
LBLuciene Pires Brandão
Luciene Pires Brandão
NANatália Cambiaghi Atilio
Natália Cambiaghi Atilio
Elcio Cruz de OliveiraElcio Cruz de Oliveira
Elcio Cruz de Oliveira
Sometimes, analytical chemicals forget that the measurement process begins with the selection of the sample; thus, it must be understood that the measurement uncertainty is constituted by the association of the uncertainty arising from the sampling and the uncertainty arising from the traditional analytical process, that which is carried out in the laboratory. The analytical process is well-controlled, so its uncertainty is well defined; however, the uncertainty arising from sampling, for not having this controlled environment, is often not evident, so that there is still no culture to consider it for the calculation of measurement uncertainty. This study discusses the importance of the sampling uncertainty concerning the analytical uncertainty and details the current approaches available in the literature, such as the classical analysis of variance, the robust analysis of variance, and the range statistics. Moreover, this work highlights the recent manuscripts that are using these mentioned approaches, correlating them to the matrices, chemical and physical-chemical analytes, and analytical techniques. Finally, some case studies using the uncertainty information in compliance assessment show that the measurement uncertainty arising from sampling in chemical and physicochemical analyses cannot always be neglected.

7 November 2021 in Critical Reviews in Analytical Chemistry
Verified
Journal Article
Closed access
KMKhrissy Medeiros
Khrissy Medeiros
AMAna Carolina Hermógenes de Matos
Ana Carolina Hermógenes de Matos
Elcio Cruz de OliveiraElcio Cruz de Oliveira
Elcio Cruz de Oliveira
Historically, owing to the increase in processing capacity over the years, validation and adjustment of measurements have become imperative. In particular, concerning discussions related to data and results in analytical chemistry, there is always a need to improve their reliability. The data reconciliation technique has the objective of using measurement redundancies to obtain the best estimate of the true value and, consequently to minimize its uncertainty. Unfortunately, this powerful tool is less known and used by analytical chemists compared to other areas. This approach can be satisfactorily performed in decision-making procedures that focus on chemical analysis, chemometrics, biochemistry analysis, forensics, and environmental sciences, such as in a characterization study, regarding conformance or nonconformance with the specification, doubts related to the malfunctioning of meters and about the compatibility of test methods. This work discusses and sheds light on the importance of data reconciliation, including data reconciliation statistics and application of the technique, traditional data reconciliation in analytical chemistry, principal component analysis based on data reconciliation in analytical chemistry, and fuzzy data reconciliation in analytical chemistry.

9 March 2023 in Water
Verified
Journal Article
Open access
PDF file
LGLaís dos Santos Gonçalves
Laís dos Santos Gonçalves
KMKhrissy Medeiros
Khrissy Medeiros
CHCARLOS HALL
CARLOS HALL
Because of economic, population, and consumption patterns changes, the use of freshwater has increased significantly in the last 100 years. Notably, measurement is essential to encourage water conservation. Thus, the present study aims to evaluate the applicability of a thin-film resistive sensor (bend sensor) with different coatings for implementation in individualized water measurement systems. The motivation of this work is to propose a volumetric meter using flow control valves that ordinarily are already present in a building’s hydraulic installations. Methodologically, the following are presented: the system developed for the electromechanical and thermal characterization of the sensor, the sensor computational simulation performed using Ansys® software, and for the electronic circuit designed in LTSpice® software, the artificial neural network used to estimate the flow and the volume estimates from the trapezoidal pulses. The results obtained allowed us to assess that, taking into account the type of coating, the sensor coated with polyester has better behavior for the proposed hydrometer. In addition, this evaluation allowed us to conclude that the bend sensor demonstrated its feasibility to be used as a transducer of this novel type of volumetric meter and can be easily inserted inside a hydraulic component, such as a flow control valve, for example.

6 November 2023 in Current Pharmaceutical Analysis
Verified
Journal Article
Closed access
PDF file
GOGuilherme Lucarelli Orsay
Guilherme Lucarelli Orsay
KMKhrissy Medeiros
Khrissy Medeiros
Elcio Cruz de OliveiraElcio Cruz de Oliveira
Elcio Cruz de Oliveira