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Navegação por autor "10632"
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NASCIMENTO, ERIBERTO O. do; BECATTI, MATHEUS J.P.; CALDAS, LINDA V.E.
; OLIVEIRA, LUCAS N. de
.
Design of Experiments (DoE) method for solar protective films via UV–Vis and NIR spectrophotometry measurements.
Journal of Luminescence,
v. 242,
p. 1-10,
2022.
DOI:
10.1016/j.jlumin.2021.118558
Abstract:
Individual dosimetry and the shielding of sun rays are needed for people in homes, at workplaces and vehicles when exposed to Ultraviolet Radiation (UVR) and/or Infrared Radiation (IR). Usually, the efficacy of Solar Protective Films (SPF) has been recognized as an important public health concern. So, this work aimed to verify, using the Design of Experiments (DoE) and Multiple Linear Regression (MLR) methods, the evaluation of solar films using the UV–Vis and NIR (Near Infrared) spectrophotometry technique for absorbance readings. In addition, the significance of the SPF manufacturing origin and glass color were evaluated. Four types of SPF, named G05, G20, G35 and WB, were tested and layered within dark and light glasses. The absorbance readings were used in a 2k factorial design analysis, then the one-way ANOVA Test and the Bonferroni Test were used to assess the statistical significance of each factor. The results showed that the statistical error, using the Root Mean Square Percentage Error (RMSPE) and the Mean Absolute Percentage Error (MAPE) methods, showed values less than 0.014% between the measured and the predicted ones, indicating excellent accuracy. In conclusion, DoE and MLR methods are suitable to be used in the investigation of the association between SPF and glass materials.
Palavras-Chave:
solar radiation;
radiation protection;
ultraviolet radiation;
spectrophotometry
NASCIMENTO, ERIBERTO O. do; BECATTI, MATHEUS J.P.; CALDAS, LINDA V.E.; OLIVEIRA, LUCAS N. de.
Design of Experiments (DoE) method for solar protective films via UV–Vis and NIR spectrophotometry measurements.
Journal of Luminescence,
v. 242,
p. 1-10,
2022.
DOI:
10.1016/j.jlumin.2021.118558.
Disponível em: http://repositorio.ipen.br/handle/123456789/32660. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, LUCAS N. de
; NASCIMENTO, ERIBERTO O.; MORAIS JUNIOR, PEDRO A.; ANTONIO, PATRICIA L.
; CALDAS, LINDA V.E.
.
Dosimetric characterization of high-linearity bone radiation detector exposed to gamma-rays.
In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Abstract:
Introduction
In radiation physics, the study of new alternative dosimeters is of interest on the growing
branch of dosimetric characterization of solid-state dosimeters for radiotherapy applications
in the Medical Physics fi elds. There are innumerous emerging techniques for reading and
processing multivariate data to assess the possible linear behavior of dosimeters; such methods
are the multivariate calibration Partial Least Square Regression (PLSR) and Principle Component
Regression (PCR) techniques. The goal of this work was to expose bone samples to high doses
and to use the FTIR spectrophotometry technique to evaluate the sensitivity and linearity of
the absorbed profi les using PLSR and PCR analyses.
Methods
Small cubes with size approximately of 0.5 cm3 composed the bone samples, used in this work.
The samples were irradiated in triplicates, with absorbed doses of 10, 100, 250, 400 and 500
Gy using a 60Co Gamma Cell-220 system (dose rate of 1.089 kGy/h); afterwards, the absorbance
spectrum of each sample was acquired on a Fourier Transform Infrared (FTIR) Spectrometer
(Frontier/Perkin Elmer) with an optical step of 1 nm from 400 nm to 4000 nm.
Results
The absorbance for high sensitivity peaks was observed for each bone sample, at the 552 nm,
991 nm and 1650 nm wavelengths in decreasing magnitude. The PLSR and PCR techniques
showed, on the range from 10 Gy to 500 Gy, for the calibration curves of the system, a linearity
of 0.9432 and 0.9422 respectively, using just three components on both methods.
Conclusions
The results indicate an acceptable linear response, and therefore this material may be an
interesting radiation detector.
OLIVEIRA, LUCAS N. de; NASCIMENTO, ERIBERTO O.; MORAIS JUNIOR, PEDRO A.; ANTONIO, PATRICIA L.; CALDAS, LINDA V.E.
Dosimetric characterization of high-linearity bone radiation detector exposed to gamma-rays.
In:
INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Disponível em: http://repositorio.ipen.br/handle/123456789/31017. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, L.N.
; NASCIMENTO, E.O.; ANTONIO, P.L.
; CALDAS, L.V.E.
.
Ethylene-vinyl acetate detector exposed to gamma radiation and evaluated via principal component regression.
In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st,
September 13-17, 2021,
Online.
Resumo expandido...
2021.
Abstract:
Introduction: Applications of ethylene-vinyl acetate
(EVA) have been reported in radiation physics research,
such as in electron beam irradiations, UV measurements
and microwave irradiations. Gamma radiation
is well known and presents several applications for radiation
dosimetry [1]. The evaluation of EVA and other
dosimeters can be undertaken by the Fourier Transform
Infrared (FTIR) spectrophotometry technique. The goal
of this work was to investigate the effect of gamma radiation
in green, white and black EVA dosimeter samples
for their sensitivity and linearity response, using the
PCR method, and evaluated with the FTIR spectrophotometry
technique.
Material and method: The EVA samples had dimensions
of 0.5 x 0.5 x 0.1 cm3, in colors green, white
and black. These samples were irradiated in triplicates,
with absorbed doses of 0.01 kGy, 0.05 kGy, 0.10 kGy,
0.25 kGy, 0.50 kGy, 1.0 kGy, 5.0 kGy and 10.0 kGy
using a 60Co Gamma Cell-220 system (dose rate of
1.089 kGy/h of the Radiation Technology Center of
IPEN); afterwards, the absorbance spectrum of each
sample was acquired on a Fourier Transform Infrared
(FTIR) spectrometer (Frontier/Perkin Elmer) from
400 cm-1 to 4000 cm-1, with 1 cm-1 spectral resolution.
The linearity of response was evaluated using the
Pearson correlation coefficient (R2). The sensitivity was
set as the linear coefficient from a simple linear
regression that was fitted using the Ordinary Least
Squares Method between the absorbed doses and
absorbance values for each wavenumber in the spectra
for all colors of EVA samples.
The PCR method combines all spectra from
absorbance measurements into a single matrix, called
here as Xnm, where n is the absorbed doses that varied
discreetly from n = 1 up to 8, matching the absorbed
doses of 0.01 kGy, 0.05 kGy, 0.10 kGy, 0.25 kGy,
0.50 kGy, 1.0 kGy, 5.0 kGy and 10.0 kGy, m is the
spectral resolution index, from m = 1 up to 3600,
equivalent to the range from 400 cm-1 to 4000 cm-1.
Results: Predicted absorbed dose versus absorbed
dose data are shown in Figure 1, for the PCR method,
for EVA samples of all colors. The R2 obtained was
1.000 for the PCR method. It can be inferred that these
methods are a good alternative, in the applications that
require assessing linearity response in dosimetry, since
the measurements from each kind of sample may be
transformed in linear results. Consequently, these methods
can be associated with other characteristics from radiation
dosimetry as: reproducibility, fading, spatial
resolution and others.
Conclusion: EVA samples can be considered as a
promising material for measurements of high doses of
gamma radiation.
Palavras-Chave:
vinyl acetate;
ethylene;
polymerase chain reaction;
electron beams
OLIVEIRA, L.N.; NASCIMENTO, E.O.; ANTONIO, P.L.; CALDAS, L.V.E.
Ethylene-vinyl acetate detector exposed to gamma radiation and evaluated via principal component regression.
In:
LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st,
September 13-17, 2021,
Online.
Resumo expandido...
2021.
Disponível em: http://repositorio.ipen.br/handle/123456789/32923. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
Como referenciar este item
-
OLIVEIRA, L.N.
; NASCIMENTO, E.O.; ANTONIO, P.L.
; CALDAS, L.V.E.
.
Ethylene-vinyl acetate detector exposed to gamma radiation and evaluated via principal component regression.
Brazilian Journal of Radiation Sciences,
v. 10,
n. 2A,
p. 1-17,
2022.
DOI:
10.15392/bjrs.v10i2A.1760
Abstract:
Ethylene-vinyl acetate (EVA) is the flexible plastic material commonly used in industries. The EVA samples, in
green, white and black colors were irradiated with absorbed doses of 0.01 kGy up to 10.0 kGy using a 60Co
Gamma Cell-220 system, and the Fourier Transform Infrared (FTIR) spectrophotometry technique was used
for evaluating the samples. This work aimed to investigate EVA samples in measurements with gamma
radiation, analyzing the linearity through the Principal Component Regression (PCR) method and its
sensitivity. For sensitivity and linearity, the green samples showed the best results, followed by white and black
EVA samples. The PCR method inflated gradually the number of principal components, then reducing the
residuals between the measured and calculated values, consequently obtaining maximum linearity of 1.000 for
all of the EVA samples. In conclusion, the FTIR was adequate for the acquisition of absorbance spectra; the
linearity via PCR and sensitivity showed good results indicating that the EVA detectors can be useful in
radiation measurements.
Palavras-Chave:
absorbed radiation doses;
cobalt 60;
dosemeters;
dosimetry;
ethylene;
fourier transformation;
regression analysis;
sensitivity;
vinyl acetate
OLIVEIRA, L.N.; NASCIMENTO, E.O.; ANTONIO, P.L.; CALDAS, L.V.E.
Ethylene-vinyl acetate detector exposed to gamma radiation and evaluated via principal component regression.
Brazilian Journal of Radiation Sciences,
v. 10,
n. 2A,
p. 1-17,
2022.
DOI:
10.15392/bjrs.v10i2A.1760.
Disponível em: http://repositorio.ipen.br/handle/123456789/33382. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, LUCAS N. de
; NASCIMENTO, ERIBERTO O. do; MORAIS JUNIOR, PEDRO de A.; ANTONIO, PATRICIA de L.
; CALDAS, LINDA V.E.
.
Evaluation of high-linearity bone radiation detectors exposed to gamma-rays via FTIR measurements.
Applied Radiation and Isotopes,
v. 170,
p. 1-6,
2021.
DOI:
10.1016/j.apradiso.2021.109598
Abstract:
In radiation physics, the study of new alternative dosimeters is of interest to the growing branch of dosimetric
characterization for radiotherapy applications. The goal of this work was to expose bone samples to high doses
and evaluate their linearity response to gamma rays. The Fourier Transform Infrared (FTIR) spectrophotometry
technique was employed as the evaluation technique, and based on the spectrophotometry absorbance profiles
the linearity was assessed based on the following methods: Area Under the Curve (AUC), Wavenumber Method
(WM), Partial Component Regression (PCR) and Partial Least-Square Regression (PLSR) methods. The bone
samples were irradiated with absorbed doses of 10 Gy up to 500 Gy using a 60Co Gamma Cell-220 system. The
results showed, for the calibration curves of the system, adequate linearity on all methods. In conclusion, the
results indicate a good linear response and therefore an interesting potential radiation detector.
Palavras-Chave:
gamma radiation;
radiation detectors;
irradiation;
dosimetry;
fourier transformation;
infrared spectra;
radiation doses
OLIVEIRA, LUCAS N. de; NASCIMENTO, ERIBERTO O. do; MORAIS JUNIOR, PEDRO de A.; ANTONIO, PATRICIA de L.; CALDAS, LINDA V.E.
Evaluation of high-linearity bone radiation detectors exposed to gamma-rays via FTIR measurements.
Applied Radiation and Isotopes,
v. 170,
p. 1-6,
2021.
DOI:
10.1016/j.apradiso.2021.109598.
Disponível em: http://repositorio.ipen.br/handle/123456789/32001. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
Como referenciar este item
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OLIVEIRA, LUCAS N. de
; NASCIMENTO, ERIBERTO O.; ANDREETA, MARCELLO R.B.; YAMAGUSHI, YASMIM Y.; JIUSTI, JEANINI; ANTONIO, PATRICIA L.
; CALDAS, LINDA V.E.
.
Evaluation of the FTIR technique for the linearity assessment of commercial soda-lime glass irradiated with gamma radiation.
In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Abstract:
Introduction
High dose dosimetry is one of the most important branches of everyday activities related to
medical and industrial applications. Nevertheless, the use of materials that respond in a linear
manner has advantages over nonlinear materials, since the dose calculation procedure in linear
materials relies solely upon direct proportions to the delivered dose. The evaluation techniques
are also important to identify the possible linear ranges, and the new Fourier-transform infrared
spectroscopy (FTIR) technique has been used to this objective. This work aims to investigate
the linearity response and its sensitivity, using mainly the FTIR technique.
Methods
Cubic samples of a soda-lime glass type with composition of Li2O.2B2O3 + 10 mol% of (0.25Li2O
+ 0.25La2O3 + TiO2) were irradiated with doses from 1 kGy to 12 kGy, using a 60Co Gamma-Cell
system 220. The response was evaluated using the FTIR technique.
Results
The sensitivity and linearity characteristics were evaluated with the absorbed profi les of the
multivariate calibration Partial Least Square Regression (PLSR), with its loadings performing a
linear regression; from the slope value, the sensitivity of the glass at the absorbed dose range
was obtained. The PLSR technique showed, on the range of 1-12 kGy, that the soda-lime glass
type presents linearity value of 0.8532 using just three components. The results of the linearity
test were obtained for the FTIR technique.
Conclusions
The FTIR technique was applied to assess the linear behavior based of the glass spectrum,
showing its usefulness to identify possible linear dose regions and also the overall sensitivity
of the glass samples to dose. Therefore, the results obtained indicate a good linear response,
showing therefore a potential use of this glass-soda lime type for radiation dosimetry in high
doses.
OLIVEIRA, LUCAS N. de; NASCIMENTO, ERIBERTO O.; ANDREETA, MARCELLO R.B.; YAMAGUSHI, YASMIM Y.; JIUSTI, JEANINI; ANTONIO, PATRICIA L.; CALDAS, LINDA V.E.
Evaluation of the FTIR technique for the linearity assessment of commercial soda-lime glass irradiated with gamma radiation.
In:
INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Disponível em: http://repositorio.ipen.br/handle/123456789/31021. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, LUCAS N. de
; NASCIMENTO, ERIBERTO O.; ANTONIO, PATRICIA L.
; CALDAS, LINDA V.E.
.
Evaluation of transparent and black commercial soda-lime glass irradiated with gamma radiation.
In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Abstract:
Introduction
The linearity characteristic in radiation dosimetry presents a growing interest. Glasses have
been applied to radiation high doses. The goal of this work was to expose transparent and dark
commercial soda-lime glasses samples to high doses and to use the UV-Vis spectrophotometry
technique for their evaluation.
Methods
Transparent and dark commercial soda-lime glasses with dimensions of 1 x 10 x 40 mm3 were
irradiated with doses from 1 kGy to 10 kGy using a 60Co Gamma-Cell system 220, and then were
evaluated with the UV-Vis technique. The sensitivity and linearity characteristics were evaluated
with the absorbed profi les of the multivariate calibration Partial Least Square Regression (PLSR)
and Principle Component Regression (PCR) techniques.
Results
The PLSR and PCR techniques showed, on the range of 1-10 kGy, for the calibration curves,
of transparent and black commercial soda-lime glass, linearity values of 0.9432 and 0.9422
respectively using just three components on both methods. The spectra present a baseline
variation (and maximum absorbance values) proportional to the absorbed dose received by the
samples. These results show that it is possible to use the technique of UV-Vis to determine
if the glass samples were irradiated or not. The color changes for transparent glass irradiated
with absorbed doses from 1 kGy up to 10 kGy. This color variation in relation to absorbed dose
indicates that the glasses may be used as YES/NO dosimeters.
Conclusions
The UV-Vis measurements may be useful in gamma radiation dosimetry, using the spectra of
irradiated glasses; the highest linearity was shown in order respectively for transparent and
black commercial soda-lime glass; the glass samples changed their coloration proportional to
the absorbed doses, and they may be used as Yes/No detectors and as high-dose dosimeters.
The results indicate a good linear response and the radiation detectors present potential use
for radiation dosimetry in high doses.
OLIVEIRA, LUCAS N. de; NASCIMENTO, ERIBERTO O.; ANTONIO, PATRICIA L.; CALDAS, LINDA V.E.
Evaluation of transparent and black commercial soda-lime glass irradiated with gamma radiation.
In:
INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Disponível em: http://repositorio.ipen.br/handle/123456789/31015. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, LUCAS N. de
; NASCIMENTO, ERIBERTO O. do; CALDAS, LINDA V.E.
.
New Fricke Xylenol Liquid detector doped with methylene blue (FXL-mblue) irradiated with red LED light.
Journal of Luminescence,
v. 230,
p. 1-9,
2021.
DOI:
10.1016/j.jlumin.2020.117730
Abstract:
In photodynamic therapy, a beam of incident light on the target causes interactions with the photosensitizing agent in the patient, subsequently killing cancerous cells through chemical and biological processes. The objective of this work was to describe for the first time the use of the FXL-mblue detector in dosimetric applications with irradiations from red LED light and using the UV–Vis spectrophotometry as an evaluation technique. The FXL-mblue samples were irradiated with doses of 2.40 kJ/cm2 up to 21.6 kJ/cm2 using a red LED light system. The results showed good results on uncertainties, sensitivity, reproducibility, repeatability, minimum detectable dose (MDD) and fading times for a promising dosimeter in measurements with visible light. In conclusion, the results indicate good dosimetric characteristics which could be used in quality control of photodynamic therapy measurements.
Palavras-Chave:
chemical dosemeters;
dosemeters;
xylenols;
methylene blue;
light emitting diodes;
ultraviolet spectrometers;
therapy;
photosensitivity
OLIVEIRA, LUCAS N. de; NASCIMENTO, ERIBERTO O. do; CALDAS, LINDA V.E.
New Fricke Xylenol Liquid detector doped with methylene blue (FXL-mblue) irradiated with red LED light.
Journal of Luminescence,
v. 230,
p. 1-9,
2021.
DOI:
10.1016/j.jlumin.2020.117730.
Disponível em: http://repositorio.ipen.br/handle/123456789/31962. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, LUCAS N. de
; NASCIMENTO, ERIBERTO O.; ANTONIO, PATRICIA L.
; CALDAS, LINDA V.E.
.
A new natural detector (Curcuma Longa L.) for photodynamic therapy (PDT) measurements with blue LED irradiations: Application of Convolutional Neural Networks (CNN) and Multilayer Perceptron (MLP).
In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 4th,
October 16-20, 2023,
Valencia, Spain.
Abstract...
Valencia, Spain: ISIRYM,
2023.
p. 71.
OLIVEIRA, LUCAS N. de; NASCIMENTO, ERIBERTO O.; ANTONIO, PATRICIA L.; CALDAS, LINDA V.E.
A new natural detector (Curcuma Longa L.) for photodynamic therapy (PDT) measurements with blue LED irradiations: Application of Convolutional Neural Networks (CNN) and Multilayer Perceptron (MLP).
In:
INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 4th,
October 16-20, 2023,
Valencia, Spain.
Abstract...
Valencia, Spain: ISIRYM,
2023.
p. 71.
Disponível em: http://repositorio.ipen.br/handle/123456789/34506. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, LUCAS N. de
; NASCIMENTO, ERIBERTO O. do; CALDAS, LINDA V.E.
.
A new natural detector for irradiations with blue LED light source in photodynamic therapy measurements via UV–Vis spectroscopy.
Photochemical and Photobiological Sciences,
v. 20,
n. 11,
p. 1381-1395,
2021.
DOI:
10.1007/s43630-021-00088-w
Abstract:
Photodynamic therapy has been recently studied, bringing innovations regarding the reduction of exposure time to light by the patient. This work aimed to investigate the feasibility of using Coutarea hexandra (Jacq.) K. Schum (CHS) as a detector in photodynamic therapy measurements. For this, an irradiator containing a blue LED bulb lamp was utilized. The CHS samples were irradiated with ten doses from 0.60 up to 6.0 kJ/cm2, and six concentrations were prepared (1, 2, 3, 4, 5, and 6 mg/ml) for the CHS detector samples. After irradiation, the detector samples were evaluated using UV–Vis spectrophotometry. The results showed the behavior of the CHS detector with doses and concentrations, its sensitivity, and its linearity was also evaluated both by Wavelength Method (WM) and the Kernel Principal Component Regression (KPCR) Statistical Method. The values obtained indicate that this method can be applied to the CHS sample detector. In conclusion, the CHS is a promising detector in the field of photodynamic therapy.
Palavras-Chave:
photodynamic therapy;
light emitting diodes;
ultraviolet radiation;
light bulbs;
radiation detectors
OLIVEIRA, LUCAS N. de; NASCIMENTO, ERIBERTO O. do; CALDAS, LINDA V.E.
A new natural detector for irradiations with blue LED light source in photodynamic therapy measurements via UV–Vis spectroscopy.
Photochemical and Photobiological Sciences,
v. 20,
n. 11,
p. 1381-1395,
2021.
DOI:
10.1007/s43630-021-00088-w.
Disponível em: http://repositorio.ipen.br/handle/123456789/32377. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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OLIVEIRA, L.N.
; NASCIMENTO, E.O.; ANTONIO, P.L.
; CALDAS, L.V.E.
.
Plastic bottle caps as radiation detectors for high gamma radiation doses.
In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st,
September 13-17, 2021,
Online.
Resumo expandido...
2021.
Abstract:
Introduction: Plastic detectors represent an important
role in radiation dosimetry [1]. They have been
used in a variety of applications, such as portal monitors,
and for solar, cosmic, UV, thermal and gamma radiations.
Dosimetric evaluation is indicated for material
characterization seeking to identify possible applications;
proper preprocessing techniques are critical features
of this process. This work aimed to determine the
linearity response of plastic samples exposed to gamma
radiation, using the Fourier Transform Infrared (FTIR)
measurements technique.
Material and method: Plastic bottle caps were used
as sample detectors. They were composed of a hollow
cylindrical shape with a 14 mm radius, 0.05 mm thickness,
28 mm height and 3.1 g mass, and they were made
of polyethylene (F217). These samples were irradiated
in triplicates, with absorbed doses of 0.01 kGy, 0.05
kGy, 0.10 kGy, 0.25 kGy, 0.50 kGy, 1.0 kGy, 5.0 kGy
and 10.0 kGy using a 60Co Gamma Cell-220 system
(dose rate of 1.089 kGy/h at the Radiation Technology
Center of IPEN). Afterwards, each sample absorbance
spectrum was acquired on a Fourier Transform Infrared
(FTIR) Spectrometer (Frontier/Perkin Elmer) from
400 cm-1 to 4000 cm-1, with 1 cm-1 spectral resolution.
The preprocessing was performed in the raw data
composed by the broadband source interferogram with
a +/- 0.04 cm-1 (2σ) precision for each absorbed dose
profile. Subsequently, applying the Fast Fourier
Transform (FFT), FTIR was generated. Then, the
derivates in the frequency (wavenumber) space were
calculated seeking to assess high-order effects.
The complex FFT coefficients were explicitly
obtained for peak regions, which provided localized
information regarding the spectrum approximate shape
from the FTIR evaluations to obtain linearity
estimatives.
The resulting FTIR spectra for each peak was to
numerical differentiation at the 1st, 2nd and 3 rd orders
(D1, D2 and D3, respectively). The derivates obtained
were useful in achieving the spectra shapes and the
linearity of response.
Results: Figure 1 presents the results after the application
of the PCR method: Predicted absorbed dose versus
absorbed dose, for: I, II and III regions (from spectrum).
The results of the PCR method are the maximum
values for linearity, 1.000 for all regions. This result
demonstrates that the PCR method is more robust than
the linear method, and the preprocessing via PCA provides
the information pertinent to the evaluated plastic
detector.
Conclusion: The results on linearity of response
show that plastic bottle caps represent potential radiation
detectors for high gamma radiation doses.
Palavras-Chave:
plastics;
radiation doses;
fourier transformation;
gamma radiation
OLIVEIRA, L.N.; NASCIMENTO, E.O.; ANTONIO, P.L.; CALDAS, L.V.E.
Plastic bottle caps as radiation detectors for high gamma radiation doses.
In:
LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st,
September 13-17, 2021,
Online.
Resumo expandido...
2021.
Disponível em: http://repositorio.ipen.br/handle/123456789/32926. Acesso em: $DATA.
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Como referenciar este item
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OLIVEIRA, L.N.
; NASCIMENTO, E.O.; ANTONIO, P.L.
; CALDAS, L.V.E.
.
Plastic bottle caps as radiation detectors for high gamma radiation doses.
Brazilian Journal of Radiation Sciences,
v. 10,
n. 2A,
p. 1-18,
2022.
DOI:
10.15392/bjrs.v10i2A.1761
Abstract:
Dosimetric evaluation is indicated for material characterization seeking to identify possible
applications; still, proper preprocessing techniques are critical features of this process. This
work aimed to determine the linearity response of plastic samples irradiated with gamma
rays using the Fourier Transform Infrared (FTIR) measurements. The plastic samples were
analyzed using Derivatives and Principal Component Analysis (PCA) methods. They applied
linear and Principal Component Regression (PCR) methods to obtain linearity. The methods
obtained good results for linearity and also showed the evolution of each technique. In
conclusion, the results indicate that the applied methods can be useful in radiation physics
and for plastic samples as interesting potential radiation detectors.
Palavras-Chave:
absorbed radiation doses;
cobalt 60;
dosemeters;
dosimetry;
fourier transformation;
gamma radiation;
polyethylene terephthalate;
principal component analysis;
radiation detectors
OLIVEIRA, L.N.; NASCIMENTO, E.O.; ANTONIO, P.L.; CALDAS, L.V.E.
Plastic bottle caps as radiation detectors for high gamma radiation doses.
Brazilian Journal of Radiation Sciences,
v. 10,
n. 2A,
p. 1-18,
2022.
DOI:
10.15392/bjrs.v10i2A.1761.
Disponível em: http://repositorio.ipen.br/handle/123456789/33384. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
Como referenciar este item
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NASCIMENTO, ERIBERTO O.; BECATTI, MATHEUS J.P.; ANTONIO, PATRICIA L.
; VIEIRA, SILVIO L.; OLIVEIRA, LUCAS N. de
; CALDAS, LINDA V.E.
.
Quality control of solar protection films via design of experiments.
In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Abstract:
Introduction
Solar radiation reaching the earth surface is broadly divided into infrared, visible and
ultraviolet radiation (UVR). Individual dosimetry and monitoring of the sun rays in humans and
environments is of interest since in homes, shops and cars the effects of UVR radiation can
bring irreparable damage to the skin and eyes. The effi cacy of solar protective fi lms has been
recognized as an important public health product. The objective of this work was the quality
control of solar fi lms using the UV-Vis spectroscopy technique via 2k Experimental Factor.
Methods
Four types of solar protective fi lms were tested: G05, G20, G35 and WB (Windom Blue), which
follow the blocking of UVR rays by 95%, 80%, 65% and 0% (76% transparent). The samples
had dimensions of 1.0 x 3.0 cm2 and the readings were taken on a GENESYS™ 10S UV-Vis
Spectrophotometer with an optical step of 1 nm from 190 nm to 400 nm. The absorbances were
used in a 2k Experimental Factor, in which the four fi lms were read individually and also with
overlap (two fi lms together). It was possible to obtain results of all the interactions among the
fi lms, with or without overlap.
Results
The results about the absorption of the sunscreen fi lms were modeled from the 2k Experimental.
This factor indicates that the best regions of the spectrum are blocked and/or where they
produce a better quality control of these materials. The region studied in this work was where
the ultraviolet radiation dosimetry can be of interest. The proposed spectrophotometric method
is rapid, simple and cost effective for the evaluation on quality control of protection fi lms.
Conclusions
The results provide information on ultraviolet radiation and they can be useful for the medical
physics community. The proposed methodology may be useful as a rapid quality control tool. It
can be used during the production process, in the analysis of the fi nal product, and can offer
important information for the scientifi c community.
NASCIMENTO, ERIBERTO O.; BECATTI, MATHEUS J.P.; ANTONIO, PATRICIA L.; VIEIRA, SILVIO L.; OLIVEIRA, LUCAS N. de; CALDAS, LINDA V.E.
Quality control of solar protection films via design of experiments.
In:
INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd,
May 27-31, 2019,
Lisboa, Portugal.
Abstract...
Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa,
2019.
Disponível em: http://repositorio.ipen.br/handle/123456789/31010. Acesso em: $DATA.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.
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A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.
O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.