TL Techniques Research Articles

Hyperspectral-to-image transform and CNN transfer learning enhancing soybean LCC estimation

Leaf chlorophyll content (LCC) is a distinct indicator of crop health status used to estimate nutritional stress, diseases, and pests. Thus, accurate LCC information can assist in the monitoring of crop growth. The combined use of hyperspectral and deep learning techniques (e.g., convolutional neural network [CNN] and transfer learning [TL]) can improve the performance of crop LCC estimation. We propose a hyperspectral-to-image transform (HIT) technique for converting canopy hyperspectral reflectance into 2D images. We designed a CNN architecture called LCCNet that fuses the deep and shallow features of CNNs to improve soybean LCC estimation. This study evaluated the combined use of hyperspectral remote sensing (RS), HIT, CNN, and TL techniques to estimate soybean LCC for multiple growth stages. The LCCNet was pre-trained based on a simulated dataset (n = 114,048) from the PROSAIL radiative transfer model (RTM) and used as prior knowledge for this work. The soybean canopy hyperspectral RS dataset (n = 910) was obtained using a FieldSpec 3 spectrometer. The knowledge gained while learning to estimate LCC from PROSAIL RTM was applied when estimating field soybean LCC (Dualex readings). TL was used to enhance the soybean estimation model, called the Soybean-LCCNet (RTM + HIT + CNN + TL) model. We tested the LCC (Dualex readings) estimation performance using (a) HIT + CNN, (b) LCCNet (RTM + HIT + CNN), (c) Soybean-LCCNet (RTM + HIT + CNN + TL), and (d) widely used LCC spectral features + partial least squares regression (PLSR). Four methods were ranked based on their LCC estimation performance: Soybean-LCCNet (R2 = 0.78, RMSE = 4.13 (Dualex readings)) > HIT + CNN (R2 = 0.75, RMSE = 4.41 (Dualex readings)) > PLSR-based method (R2 = 0.61, RMSE = 5.39 (Dualex readings)) > LCCNet (R2 = 0.53, RMSE = 7.11 (Dualex readings)). The main conclusions of this work are as follows: (1) HIT + CNN can provide a more robust LCC estimation performance than the widely used LCC SIs; (2) Fusing the deep and shallow features of CNNs can improve the performance of RS soybean LCC (Dualex readings) estimation; and (3) Soybean-LCCNet can reuse the CNN layer information of a pre-trained LCCNet based on a PROSAIL RTM dataset and improve the soybean LCC estimation performance.

Investigation of radioactivity level in drinking water resources and soil samples collected from the Hawraman villages, Iraq

In the present study, the RAD7 and NaI(Tl) techniques were utilized to determine the radon concentrations in drinking water resources and the natural primordial radionuclides in soil samples collected from Hawraman villages. The measured radon concentrations ranged from 1.7 ± 0.6 to 34.0 ± 2.8 Bq L−1 with an arithmetic mean of 14.8 ± 1.2 Bq L−1. This research demonstrates that roughly 54% of drinking water samples exceed the EPA-recommended level of 11.1 Bq L−1. For adults, children, and infants, the total annual effective doses for the three types (Ding, Dinh, and Ddi) vary from 7.6 to 149.2 μSv y−1 with an average of 65.0 μSv y−1, 8.1–160.0 μSv y−1 with an average of 69.7 μSv y−1, and 10.5–207.0 μSv y−1 with an average of 90.2 μSv y−1.18.2%, 22.7%, and 36.4%, respectively, of the annual effective dose for adults, children, and infants exceeds the 100 μSv y−1 level recommended by WHO and UNCEAR 2000.The activity concentrations of 226Ra, 232Th, and 4 K in soil samples varied from 10.9 ± 0.1 to 32.6 ± 0.2 Bq kg−1, 18.3 ± 0.4 to 52.1 ± 0.6 Bq kg−1, and 252.7 ± 2.5 to 585.6 ± 3.7 Bq kg−1. The arithmetic mean concentrations of 226Ra, 232Th, and 4 K were determined to be 19.4 ± 0.2 Bq kg−1, 36.2 ± 0.5 Bq kg−1and 426.6 ± 3.2 Bq kg−1, respectively.This research reveals that the average soil activity concentrations of 226Ra, 232Th, and 4 K are within the global average limits of 32, 45, and 420 Bq kg−1, respectively. Comparing the concentrations to global averages, some soil samples revealed significant amounts of radionuclides, with around 18% of 232Th and 41% of 4 K. The computed radiological hazard indices of 100% of Raeq., 82% of Dout, 82% of Eout, and 95.5% of ELCRout are all below the internationally recommended levels declared by Unscear 2000.

Challenges in personal and clinical dosimetry using Li2B4O7 and MgB4O7 as TLD and OSLD

Thermoluminescent (TLD) and optically stimulated luminescent dosimeters (OSLD) are essential in radiation dosimetry. Such dosimeters can be easily transported due to their small size and can be used in in vivo dosimetry and anthropomorphic simulations. In this work, the dosimetric properties of Li2B4O7 and MgB4O7 compounds were evaluated based on their response to the applied stimulus, whether thermal or optical. The linear dose response range of the luminescent signal, its fading, the lowest detectable dose, and reproducibility are important parameters in determining a good dosimeter for clinical and personal dosimetry. Therefore, the objective of this work was, based on studies performed by other authors on dosimetric characterizations of doped a codoped Li2B4O7 and MgB4O7, to point out those compounds with the greatest potential for applications in personal and clinical dosimetry using TL and OSL techniques. Considering the results described in other works, the materials that stood out for use in personal and clinical dosimetry were Li2B4O7:Cu and MgB4O7:Dy,Na. In several of the reported studies, no data related to LDD, fading and reproducibility of the luminescent signal of the investigated compounds were found. Therefore, there are many possibilities for investigations into these two types of compounds for the purpose of their use in personal and clinical dosimetry. Further studies will provide a broader scientific basis for choosing appropriate dosimetric materials for these applications.

TL and OSL studies on irradiated nano barium strontium sulfate to photons, electrons and protons

TL and OSL signals of nano-(Ba0·88Sr0·12SO4)99.8%:Eu0.2% (B88n) irradiated at doses ranging from 0.07 to 2 Gy with different beam qualities are investigated. Both TL and OSL signals show a linear response relationship, though with large variation between the slopes, due to the non water-equivalence of the Ba compounds. The measured factors for energy dependence turn to be in accordance, within uncertainties, with the calculated ones for all beam qualities, except for the 15 MV beam. For this beam, an accelerator different from the one used in this study was used to extract the data obtained for the energy spectrum. Detection limits for B88n/TL system range from a minimum value of 48 mGy (137Cs) to a maximum value of 180 mGy (16 MeV electrons), while for B88n/OSL system, a minimum value of 122 mGy (6 MV photons) to a maximum value of 153 mGy (137Cs). Nevertheless, these OSL limits can be lowered using lower doses and increasing the data points. These values make this dosimeter a suitable candidate for dosimetry applications in radiation therapy using both TL and OSL techniques.

Luminescence characteristics of perovskite type LaAlO3:Dy3+ for radiation detector

Thermally and Optically Stimulated Luminescence (OSL) are known stimulated phenomena in condensed matter that can be used for luminescent material characterization. Both thermally and optically processes have become a successful practical tool in radiation dosimetry. Special attention is dedicated to bioceramic as a material of choice for many dosimetric applications. This paper reports experimental results of dysprosium trivalent ion doped lanthanum aluminate (LaAlO3:Dy3+) using thermally stimulated luminescence (TSL) and optically stimulated luminescence (OSL) techniques. Samples of LaAlO3:Dy3+ were irradiated to beta doses, in air, from 1.6 Gy up to 26 Gy and then were analyzed using both TL and OSL techniques to determine their luminescent properties. Nanostructured powders were confirmed by the X-ray diffraction technique. Luminescent phosphors show a thermoluminescent glow curve obtained being exposed beta radiation of two peaks: one located at around 160 °C and the second one at 215 °C. Meanwhile, OSL decay is exponential form. TL and OSL response as a function beta radiation dose was linear in the studied dose interval (from 1.6 Gy up to 26 Gy). The very good sensitivity and moderate fading will make this phosphor suitable for beta radiation detection, using both TL and OSL techniques.

Fading estimation of SOL-GEL α-Al2O3 detectors

The OSL and the TL techniques are used in several fields of radiation dosimetry. The dosimeters are affected by a signal loss in the time between the irradiation and readout (fading). This undesirable characteristic can cause an underestimation of the irradiation dose. The fading estimation of SOL-GEL α-Al2O3 with several different concentrations of impurities is reported. The thermal fading and the light-induced fading of the SOL-GEL α-Al2O3 detectors were estimated. Furthermore, the exponential equations used to interpolate the experimental results were presented.

Spatial differences in the luminescence sensitivity of quartz extracted from Carpathian Basin fluvial sediments

The luminescence sensitivity of a sample is the luminescence intensity measured in response to unit radioactive dose. Sensitivity is by no means a stable parameter, it might change during measurements, or in nature as well. The primary or natural magnitude of luminescence sensitivity is basically determined by mineralogical background (number of crystal impurities) and sedimentary prehistory (repeated exposure of the sediment to sunlight). In the present study we have investigated the luminescence properties and sensitivity of coarse-grain (90–150 μm) quartz samples related to four major rivers of the Carpathian Basin (River Danube, Tisza, Szamos and Maros). In case of each region of interest 5 previously dated Late Pleistocene and/or Holocene samples were selected, each representing similar sedimentary environments, i.e. coarse grain channel deposits related to point bars and medial bars. Sensitivity was investigated using CW-OSL, LM-OSL and TL techniques using a multi-grain approach. By determining the normalised luminescence response to the same regeneration dose administered after bleaching, sensitivity base values were obtained for each sample. Using repeated cycles of dosing laboratory sensitivity change was also recorded. The base values and sensitivity change of the 20 investigated samples were then compared on a regional basis to identify potential differences, which might be used later for fingerprinting the sediments of the investigated rivers. When considering mean sensitivity base values, calculated from several aliquots of the same sample, Danube related, mostly Alpine origin sediments exhibited 50–60% lower values compared to those with a Carpathian origin, and even at the considerable standard deviation obtained (coefficient of variation being 25–60%) they could be clearly separated using any of the measured luminescence sensitivity parameters. The discrimination of fluvial sediments with a Carpathian origin, but representing different catchments, is less straightforward, though, plotting against different sensitivity parameters can offer an opportunity to define fairly distinct groups of sample mean values. From this aspect total LM-OSL and fast component ratio seemed to be the best candidates, however, at the characteristic standard deviation and standard error separation can be unclear. No clear relationship was found in terms of sensitivity change, however some samples, related to River Maros showed practically no change during the laboratory sensitisation process. When plotting OSL ages against quartz sensitivity clear trends could be recognised, which can partly be explained by geomorphological reasons. Results in all, point to the possibility to differentiate Carpathian Basin fluvial sediments on the basis of their quartz luminescence sensitivity, a parameter that can be assessed easily during the routine dating process. • The OSL sensitivity of Carpathian Basin fluvial quartz shows spatial variability. • The quartz of Danube sediments with an Alpine background is outstandingly dim. • By combining sensitivity parameters sediment sourcing can be more efficient. • Relationship between age and sensitivity is also affected by morphological processes.

Effect of Cr3+-doping concentration on luminous intensity of Zn1.4Al1.2Ge0.4O4: xCr3+

Zn1.4Al1.2Ge0.4O4: xCr3+ (x = 0.1%, 0.25%, 0.5%, 1%, 2%) phosphors were prepared at 1400 °C by conventional solid-state reaction, and their phase compositions and luminescence properties were well characterized by means of XRD, photoluminescence spectra, decay curves and TL techniques. With Cr3+ doped Zn1.4Al1.2Ge0.4O4: xCr3+ phosphors exhibited near-infrared emission at 696 nm due to the 2E → 4A2 transition of Cr3+ ions. The experimental results reveal that the Cr3+ doping concentration plays the crucial role in the luminescence performance of Zn1.4Al1.2Ge0.4O4: xCr3+ phosphors. When the Cr3+ concentration was determined to be 1%, Zn1.4Al1.2Ge0.4O4: Cr3+ phosphors obtained optimal the luminescence and afterglow performance. The mechanism of phosphor has been discussed. And the TL results revealed the depth and concentration of traps in the phosphor will be affected by the Cr3+ doping concentration.

TL/OSL signal of CaSO4:Eu,Ag samples produced by variations of the slow evaporation route

The aim of this work was to produce crystals of CaSO4 doped with europium (Eu) and silver (Ag) nanoparticles, by means of three different preparation routes, and to study their applicability in radiation dosimetry by the TL and OSL techniques. The crystals were produced by variations of the slow evaporation route. Samples of CaSO4:Eu,Ag(a) were obtained using europium oxide and silver particles as dopants. For the growth of the crystals of CaSO4:Eu,Ag(b), silver was incorporated in nitrate form. CaSO4:Eu,Ag(c) phosphorus were synthetized mixing europium oxide in a colloidal suspension of silver nanoparticles. Optical characterization confirmed the presence of Eu3+/Eu2+ in the crystal matrix. Dosimetric characteristics were evaluated after the exposure of the samples to a90Sr/90Y source. The CaSO4:Eu,Ag(a) and CaSO4:Eu,Ag(b) composites presented the most intense signals, the lowest detectable doses, and showed a linear and reproducible dose response, but the CaSO4:Eu,Ag(a) samples showed the best potential for application in TL/OSL dosimetry.

Thermoluminescence, elastic and dielectric investigations of calcium fluoro borophosphate glass composite materials doped by small concentrations of TiO2

The glasses of composition [(B2O3)10(P2O5)60]–[(CaF2)(30-x):(TiO2)x] (0 ≤ x ≤ 1 mol%) are synthesized. Prepared glasses are characterized by TL, elastic, and dielectric Techniques. The results obtained recommend that the TiO2 do exist in both divalent (Ti3+) (cm3 mol−1) and trivalent (Ti4+) states. The evaluations of refractive index (μ = 1.501), molar volume (V = 23.764 cm3 mol−1), Young’s and shear modulus (Y = 15.64 GPa and G = 15.04 GPa), and microhardness (H = 9.56 GPa) suggest that the sample of 0.6 mol% of TiO2 concentration (T6) exhibits covalently associated interlinked structure. TL measurements suggest that the sample of 0.6 mol% of TiO2 concentration (T6) exhibiting good shape symmetry factor (u = 0.247) and low AE’s ( $$ E_{\tau } $$ = 0.485 eV, $$ E_{\delta } $$ = 0.312 eV and $$ E_{\omega } $$ = 0.234 eV) under 20 min of UV irradiation might be good TL asset. Dielectric evaluations such as density of energy states (N(Ef) = 3.125 eV−1/cm3), temperature region of relaxation (149–167 °C), loss tangent (Tan δ = 0.0896), AC conductivity $$ \sigma_{\text{dc}} $$ = 4.52 × 10−8, Ω−1 cm−1), and activation energy (Ea = 1.703) of the sample (T6) suggest that good amounts of polaron hopping might be good dielectric asset.

SOL-GEL α-Al2O3 detectors: TL and OSL response to beta radiation beams

The dosimetric properties of the SOL-GEL α-Al2O3 detectors with several different concentrations of impurities were studied in beta radiation beams. For the characterization of the detectors, the TL and OSL techniques were used. A TL spectrum was acquired. The detectors showed adequate OSL and TL dosimetric characteristics, such as good reproducibility, a glow curve with the peak at ~230 °C at 5 °C/s of heating rate, adequate OSL decay curve, good linearity of response and high phosphor sensitivity. A thermal treatment study was also performed. Moreover, the calibration factors and the lower detection limits were determined for beta radiation. These characteristics indicate the suitability of SOL-GEL α-Al2O3 detectors for the establishment of a transfer system or alternative/complementary method for beta radiation dosimetry.

TL and OSL dosimetric characterization of different luminescent materials for clinical electron beams application in TSEB treatments

Thermoluminescent dosimeters (TLDs) play an important role in radiotherapy for the dosimetry of ionizing radiation. This type of dosimeter presents advantages that makes them a useful tool for measurements in anthropomorphic phantoms and in vivo dosimetry. Several dosimetric materials have been used in the radiotherapy sectors such as LiF, µLiF, CaSO4:Dy. The OSL dosimetry has also been widely applied using Aluminum Oxide (Al2O3:C). These dosimeters have advantages over TLDs due to their high sensitivity, extensive linearity in response to the dose, faster reading, possibility of multiple readings and the need to perform the heat treatment of the samples. The aim of this work was to compare and characterize, using TL and OSL techniques, different luminescent dosimeters (LiF, µLiF, CaSO4:Dy and Al2O3:C) to be applied in clinical electron beam used to TSEB treatments. Measurements were performed in order to study the applicability of these detectors as easy-to-take alternatives to calibration and measurements of TSEB treatments. Parameters such as dose-response curves; average sensitivity to radiation, intrinsic efficiency and energy and angular dependences were evaluated. The results show good agreement within CaSO4:Dy and TLD-100 measurements and, applying energy and angle dependence factors over the other two materials, all the four detectors can be applied as alternative easy-to-take dosimetric tools for commissioning and quality assurance of 6 MeV clinical electron beams used in TSEB treatments.

Dosimetric evaluation employing TL and OSL techniques with different luminescent materials for clinical evaluation of extremity doses using electron beams applied to Total-Irradiation-of-Skin treatments

Total-skin electron beam (TSEB) irradiation is used to deliver a homogeneous dose distribution over the entire skin surface of a patient. TSEB dosimetry is quite complex as to the evaluation and measurement of absorbed dosage in the cutaneous region. This paper evaluates the performance of different dosimetric materials, using TL and OSL dosimetry, in the extremity-dose assessment of TSEB treatments using the six-dual-field technique and an anthropomorphic phantom. Dosimeters were selected with repeatability better than [Formula: see text] and calibrated to 6-MeV electron-beam dosimetry. Measurements were conducted in the abdominal region as a reference point and on the extremities. Results show expected deviations ranging up to [Formula: see text] in the dose received in the extremities and good results in dose assessment using all dosimetric materials tested.

Improving Deep Reinforcement Learning with Knowledge Transfer

Recent successes in applying Deep Learning techniques on Reinforcement Learning algorithms have led to a wave of breakthrough developments in agent theory and established the field of Deep Reinforcement Learning (DRL). While DRL has shown great results for single task learning, the multi-task case is still underrepresented in the available literature. This D.Sc. research proposal aims at extending DRL to the multi- task case by leveraging the power of Transfer Learning algorithms to improve the training time and results for multi-task learning. Our focus lies on defining a novel framework for scalable DRL agents that detects similarities between tasks and balances various TL techniques, like parameter initialization, policy or skill transfer.

Dating stalagmite from Caverna do Diabo (Devil´S Cave) by TL and EPR techniques.

A cylindrical fragment of stalagmite from Caverna do Diabo, State of São Paulo, Brazil, has been studied and dated by thermoluminescence and electron paramagnetic resonance techniques. The thermoluminescence glow curves of stalagmite samples and subsequently gamma irradiated, have shown rise of three peaks at 135, 180 and 265 °C. From electron paramagnetic resonance spectra of stalagmite was possible to clearly identify three paramagnetic centers in the g = 2.0 region: Centers I, II and III are due to , and , respectively. The additive method was applied to calculate the accumulated dose using thermoluminescence peak at 265 °C and the electron paramagnetic resonance signal at g = 1.9973 of CO- 2 radical. The ages of the different slices of stalagmite were determined from the Dac- values and Dan- value, obtaining an average of 86410 for central slice, 53421 for second slice, 31490 for third slice and 46390 years B.P. for the central region of upper end.

Green, orange and reddish color emitting rare earth activated Ca2BO3Cl phosphor for solid state lighting applications

In this paper we report the combustion synthesis of trivalent rare-earth (RE3+=Tb and Eu) activated Ca2BO3Cl phosphor. The prepared phosphors were characterized by the X-ray powder diffraction (XRD) and CIE and PL and TL techniques. Photoluminescence emission peaks of Ca2BO3Cl:Tb3+ phosphor at 546nm in the green region of the spectrum excited by 352nm. The prepared Eu3+ doped phosphors were excited by 396nm then we found that the characteristics emission of europium ions at 594nm (5D0→7F1) and 620nm (5D0→7F2). The chromaticity coordinates for the prepared compound is found to be Cx=0.272, Cy=0.716 for Tb3+ and Cx=0.592, Cy=0.406,Cx=0.686, Cy=0.307 for Eu3+ ions estimated from the emission spectra of prepared sample with both activators. In present study the trapping parameters such as order of kinetics(b), activation energy(E) and frequency factors(s) have been calculated for the glow peaks of Ca2BO3Cl:Tb3+ by using Chen’s method.

A survey of transfer learning for collaborative recommendation with auxiliary data

Intelligent recommendation technology has been playing an increasingly important role in various industry applications such as e-commerce product promotion and Internet advertisement display. Besides user feedbacks (e.g., numerical ratings) on items as usually exploited by some typical recommendation algorithms, there are often some additional data such as users׳ social circles and other behaviors. Such auxiliary data are usually related to user preferences on items behind numerical ratings. Collaborative recommendation with auxiliary data (CRAD) aims to leverage such additional information so as to improve personalized services. It has received much attention from both researchers and practitioners.Transfer learning (TL) is proposed to extract and transfer knowledge from some auxiliary data in order to assist the learning task on the target data. In this survey, we consider the CRAD problem from a transfer learning view, especially on how to enable knowledge transfer from some auxiliary data, and discuss the representative transfer learning techniques. Firstly, we give a formal definition of transfer learning for CRAD (TL-CRAD). Secondly, we extend the existing categorization of TL techniques with three knowledge transfer strategies. Thirdly, we propose a novel and generic knowledge transfer framework for TL-CRAD. Fourthly, we describe some representative works of each specific knowledge transfer strategy in detail, which are expected to inspire further works. Finally, we conclude the survey with some summarized discussions and several future directions.

A new luminescence chronology for the Mangshan loess-palaeosol sequence on the southern bank of the Yellow River in Henan, central China

An unusually thick loess-palaeosol sequence was found at Mangshan on the southern bank of the Yellow River, central China. Previous attempts to establish its chronology using TL and IRSL techniques have left major uncertainty over the stratigraphic division of the sequence. Here, we report results of a quartz and polymineral luminescence dating study on medium-grain (45–63 μm) fractions from the upper five loess units of the sequence. The base of the first loess unit is dated to 68.6 ± 4.9 ka with quartz extracts. While the quartz SAR age for the top of the second loess unit is 87.2 ± 6.1 ka, the application of an elevated temperature post-IR IRSL (pIR200IR290) SAR procedure to polymineral fraction from the same sample yields an age of 137 ± 10 ka. Using this procedure, the upper five loess units are dated. Our new luminescence dates show that the uppermost ∼41 m loess accumulated during the last glaciation. This disagrees with the previously published luminescence ages but is consistent with the proposed stratigraphy based on the correlation with sections in the Loess Plateau. The accumulation rates of the Mangshan loess during the last two climate cycles are found 4–7 times higher than those in the central Loess Plateau as well as those in the lower part of the sequence. Measurements of quartz OSL/TL sensitivity reveal significant differences among the samples in different loess units, hence providing evidence for the changes in the supply of source materials as a cause for the dramatic acceleration in loess accumulation.

TL and EPR correlations in a quartz-like silicate mineral

A sample of silicate mineral considered as being jadeite but revealed to be more quartz-like, therefore named JQ2 has been studied concerning its TL and EPR properties. This study revealed a full correlation between the 210 °C TL peak and the g=2.0025 EPR signal. In both cases, the centers disappear at the same temperature and are restored after gamma irradiation. The TL peak at 210 °C may be related to the E'1 centers formed on irradiation. JQ2 responds to very high γ-dose and can be used as a high-dose dosimeter using TL and/or EPR techniques.

Experimental photon energy response of different dosimetric materials for a dual detector system combining thermoluminescence and optically stimulated luminescence

Precise knowledge of the energy response of radiation detector materials is necessary for accurate dose measurements, because the usual TL and OSL material response relative to the medium of interest (air, water or tissue) varies with beam energy. In this work, we experimentally evaluated the photon energy dependence of different materials used as detectors (Al2O3:C – Luxel, BeO – Thermalox 995, LiF:Mg,Ti – TLD100 and Brazilian pellets based on CaSO4:Dy and CaF2:natural) in personal dosimetry through OSL and TL techniques, using optimized readout parameters for each material and radiation qualities similar to real situations of exposure. It is well known that depending on the material's effective atomic number and type of stimulation, the photon energy response can present either an under-response relative to air in the low energy range, as is the case of BeO, or a large over-response, as Al2O3, CaSO4 and CaF2, or even a very flat-response, as LiF. By utilizing intrinsic characteristics of these materials combined with OSL and TL techniques, we evaluated ratios of relative photon energy responses between pairs of OSL (OSLD) and TL (TLD) detectors. We have noted that for all combinations of materials (Al2O3/LiF, CaSO4/BeO, and CaF2/BeO), the ratio of energy responses of each pair did not change significantly with energy in the intervals below 50 or above 300 keV. On the other hand, in the range of energies between 50 and 300 keV, there was a strong change in the ratio values, indicating that the ratio of detector responses well-discriminates the incident photon energy. By using these outcomes, it was possible to apply dose corrections with respect to energy using ratios of OSL and TL signals of dosimeters exposed to unknown radiation beam qualities and to determine doses in a blind test. Our results point out that this methodology could be employed to correct photon energy responses of a personal dosimeter based on both OSL and TL techniques. OSL advantages (fast readout, possibility of various partial readings and of determining accumulated doses) would be associated with the TL ones (large variety of dosimeters commercially available and use of glow curve as a readout quality control) in a dual detector system capable of determining photon energy and dose, without using attenuation filters. This new methodology might improve dose evaluation in personal dosimetry.