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This article reports TL response for different glass modifier and doping concentration. Alkali oxides (Na2O and Li2O) and alkali earth oxide (CaO) will be used as a glass modifier for strontium borate based glass. The samples were prepared by melt quenching technique. Dy2O3 concentrations ranging from 0.00 to 0.70 mol% and exposure doses of 1 to 9 Gy will be varied. All glass samples exhibit the prominent peak temperature positioned at 186 oC to 232 oC. From all the samples, one of the samples shows an excellent linearity dose response, higher TL and show good reproducibility after 5 cycles exposure which is sodium strontium borate doped with 0.1 mol% Dy2O3 (optimum concentration).

Within two mean-field plus correlation descriptions (Hartree-Fock plus BCS or plus Highly Truncated Diagonalization Approaches) we study here some static properties of two odd-neutron nuclei (235U, 239Pu) from the ground-state deformation to the fission isomeric well, using three different Skyrme force parametrizations. A specific study of the polarization effects due to the account of relevant time-odd density functions is performed.

This article reports the characteristics of thermoluminescence (TL) dosimeter of dysprosium doped strontium borate glass for NaO, Li2O, and CaO modifiers imposed by 10–90 Gy dose of 60Co gamma ray irradiation. The different elements are (70.0 – x) B2O3–20SrO–10NaO–xDy2O3, 10Li2O–20SrO–(70 – x)B2O3–(x)Dy2O3 and 10CaO–20SrO–(70.0 – x)B2O3–(x)Dy2O3 (x = 0, 0.10, 0.30, 0.50, 0.70 mol %). The glass was formed by melt quenching method and the ranges of Dy2O3 were 0.0 to 0.7 mol %. Calcium strontium borate doped with 0.3 mol % Dy2O3 shows very good linearity on dose response and gives an excellent sensitivity at 50 Gy dose of 60Co gamma ray irradiation. The samples N1, L1, C3 were completely amorphous. The optimums anneal temperature, time, concentration of Dy2O3 and heating rate were investigated for glass samples N1, L1, C3. The systematic characteristics of glow curve, TL intensity, reproducibility, sensitivity, kinetic parameters and effective atomic number were studied for three selected samples. All samples show the maximum peak from 154–200°C temperatures. [ABSTRACT FROM AUTHOR]

New glasses of zinc lithium borate doped with terbium oxide were synthesized by high temperature solid-state reaction. The amorphous nature of the glasses was confirmed using x-ray diffraction analysis (XRD). Thermoluminescence (TL) response of pure zinc lithium borate (ZLB) and zinc lithium borate doped with terbium (ZLB: Tb) exposed to gamma radiation was measured and compared. There is significant enhancement in the TL yields of ZLB: Tb compared to that of pure ZLB. Effect of varying concentration of dopant (Tb 4 O 7 ) on the TL response of zinc lithium borate was investigated. 0.3 mol% concentration of Tb exhibited strongest TL intensity. Thermoluminescence curve of the phosphor consist of single isolated peak. The TL response of the new materials to the exposed radiation is linear within 0.5–100 Gy range of dose with sublinearity at the lower region of the curve. High sensitivity was exhibited by the new amorphous materials. Reproducibility, thermal fading and energy response of the proposed TLD were investigated and shows remarkable result that made the phosphor suitable for radiation dosimetry. [ABSTRACT FROM AUTHOR]

There is continuous search for materials having superior optical and structural properties in glass photonics, thermoluminescence dosimetry and phosphors fields. A new series of copper (Cu)/strontium (Sr) co-doped lithium borate glasses (LB:Sr, Cu) of composition (85 − x )H 3 BO 3 –15Li 2 CO 3 –2SrCO 3 – x Cu 2 O , where x = 0.005 to 0.1 mol% were prepared using melt quenching method. Synthesized glasses are characterized to determine the concentration's effect of copper ions (Cu 2 + ) on modification of the structural and optical properties. XRD patterns confirmed the amorphous nature and FESEM verified the homogeneous surface morphology. EDX spectra authenticated the accurate elemental traces. Glasses are thermally stable with Hurby parameter ~ 0.5. Glass density decreases with the increasing Cu 2 + concentration. FTIR peaks in the range of 698–1070 cm − 1 attribute to trigonal and tetrahedral stretching vibrations of BO 3 and BO 4 units. The direct/indirect band gap and Urbach energy vary from 3.1–2.8 eV/2.94–2.84 eV and 1.2–2.18 eV, respectively. The observed increase in refractive index ascribed to the conversion of BO 4 into BO 3 units. PL spectra under 280 nm excitations display two peaks centered at 482 and 526 nm accompanied by slight peak shift towards the lower wavelength. Excellent structural and spectroscopic characteristics of the present glass compositions indicate prospects for various photonic devices. [ABSTRACT FROM AUTHOR]

Undoped and dysprosium doped lithium borate glass system with empirical formula (70– x ) B 2 O 3 –30 Li 2 O–( x ) Dy 2 O 3 ( x =0.1, 0.3, 0.5, 0.7, 1.0 mol%) were prepared using the melt-quenching technique. The dosimetric measurements were performed by irradiating the samples to 6 MV photon beam using linear accelerator (LINAC) over a dose range of 0.5–5.0 Gy. The glass series of dysprosium doped lithium borate glass produced the best thermoluminescence (TL) glow curve with the highest intensity peak from sample with 1.0 mol% Dy 2 O 3 concentration. Minimum detectable dose was detected at 2.24 mGy, good linearity of regression coefficient, high reproducibility and high sensitivity compared to the undoped glass are from 1.0 mol% dysprosium doped lithium borate glass. The results indicated that the series of dysprosium doped lithium glasses have a great potential to be considered as a thermoluminescence dosimetry (TLD). [ABSTRACT FROM AUTHOR]

The activity concentrations of uranium and toxic elements in Dei-Dei borehole, Kubwa borehole, Water Board and hand-dug well water samples in Abuja area were measured using inductively coupled plasma mass spectrometry (ICP-MS) system. The results obtained were used to calculate human radiological risk over lifetime consumption by the inhabitants in the area. The activity concentrations of 238 U in all the water supplies for drinking ranges from 0.849 mBq L −1 to 2.699 mBq L −1 with the highest value of 2.699 mBq L −1 noted at Dei-Dei borehole whereas the lowest value of 0.849 mBq L −1 was noted in Kubwa borehole. The highest annual effective dose from natural 238 U in all the water samples was found in Dei-Dei borehole with a value of 8.9×10 −5 mSv y −1 whereas the lowest value was noted in Kubwa borehole with a value of 2.8×10 −5 mSv y −1 . The radiological risks for cancer mortality were found distinctly low, with the highest value of 1.01×10 −7 reported at Dei-Dei borehole compared to Kubwa borehole with a value of 3.01×10 −8 . The cancer morbidity risk was noted higher in Dei-Dei borehole with a value of 1.55×10 −7 whereas lower value of 4.88×10 −9 was reported in Kubwa borehole. The chemical toxicity risk of 238 U in drinking water over a lifetime consumption has a value of 0.006 μg kg −1 day −1 in Dei-Dei borehole whereas lower value of 0.002 μg kg −1 day −1 was found in Kubwa borehole. Measured lead (Pb) and chromium (Cr) concentrations reported higher in Water Board compared to Dei-Dei and Kubwa borehole samples. Significantly, this study inferred that the 238 U concentrations originate from granitic strata of the tectonic events in the area; thus, there was a trend of diffusion towards north to south and re-deposition towards Dei-Dei area. [ABSTRACT FROM AUTHOR]

The effect of dysprosium ion (Dy3+) on the optical absorption and band gap energy of strontium borate glass systems prepared by melt quenching technique have been reported. The results show that the broad absorption edge of doped glasses shifts back and forth as a function of Dy2O3 concentrations. The intensities of five prominent and two weak optical transitions change accordingly with Dy2O3 concentrations. The defect centres are induced with the presence of Dy3+ ions in glass samples. This attributes to the intra-configurational (f-f) transitions of Dy3+ ions in glass network. In addition, the decreasing trend of optical band gap energy and Urbach energy can be related to defect centres created by Dy3+ ions. The FTIR study reveals the presence of BO3, BO4 vibration groups and the bending of B-O-B units. The asymmetric stretching of BO3 and BO4 was apparent at higher Dy2O3 concentrations. More tetrahedral BO4 units were formed by increasing Dy2O3 concentrations. The dependency of Dy2O3 concentrations on the optical properties is further discussed with other important physical properties. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study is to investigate the thermoluminescence properties of germanium doped calcium borate glass for thermoluminescence dosimeter used. Glasses with composition (30−x) CaO–70B2O3: xGeO2 where x=0.1, 0.2, 0.3, 0.4 and 0.5mol% were prepared using a melt-quenching method. The glasses were irradiated to 60Co gamma ray with doses ranging from 0.5Gy to 4.0Gy. The amorphous phases were identified for all glass samples. The glow curves were analyzed to determine various characterizations of a thermoluminescence dosimeter of the glass. It was found that the sample with a concentration of 0.1mol% GeO2 has the best thermoluminescence characteristics such as linearity, sensitivity, fading characteristic, minimum detectable dose and effective atomic number. The results clearly showed that germanium doped calcium borate glass has a potential to be considered as the thermoluminescence dosimeter. [Copyright &y& Elsevier]

The distribution of natural radionuclides (238U, 232Th and 40K) and their radiological hazard effect in rocks collected from the state of Johor, Malaysia were determined by gamma spectroscopy using a high-purity germanium detector. The highest values of 238U, 232Th and 40K activity concentrations (67±6, 85±7 and 722±18 Bg kg–1, respectively) were observed in the granite rock. The lowest concentrations of 238U and 232Th (2±0.1 Bq kg−1 for 238U and 2±0.1 Bq kg−1 for 232Th) were observed in gabbro rock. The lowest concentration of 40K (45±2 Bq kg−1) was detected in sandstone. The radium equivalent activity concentrations for all rock samples investigated were lower than the internationally accepted value of 370 Bq kg−1. The highest value of radium equivalent in the present study (239±17 Bq kg−1) was recorded in the area of granite belonging to an acid intrusive rock geological structure. The absorbed dose rate was found to range from 4 to 112 nGy h−1. The effective dose ranged from 5 to 138 μSv h−1. The internal and external hazard index values were given in results lower than unity. The purpose of this study is to provide information related to radioactivity background levels and the effects of radiation on residents in the study area under investigation. Moreover, the relationships between the radioactivity levels in the rocks within the geological structure of the studied area are discussed. [ABSTRACT FROM AUTHOR]

This work aimed to study the capability of INAA absolute method in determining the elemental concentration of U and Th in the rock samples. The INAA absolute method was implemented in PUSPATI TRIGA Mark II research reactor, Malaysian Nuclear Agency (NM). The accuracy of INAA absolute method was performed by analyzing the IAEA certified reference material (CRM) Soil-7. The analytical results showed the deviations between experimental and certified values were mostly less than 10 % with Z-score in most cases less than 1. In general, the results of analysed CRM Soil-7 show a good agreement between certified and experimental results which mean that the INAA absolute method can be used accurately for elemental analysis of uranium and thorium in various types of samples. The concentration of U and Th ranged from 1.77 to 24.25 and 0.88 to 95.50 ppm respectively. The highest value of U and Th was recorded for granite rock sample G17 of U and sample G9 of Th, whereas the lower value was 1.77 ppm of U recorded in sandstone rock and 0.88 ppm of Th for gabbro. Moreover, a comparison of the U and Th results obtained by the INAA absolute method shows an acceptable level of consistency with those obtained by the INAA relative method. [ABSTRACT FROM AUTHOR]

In this work, we studied the thermoluminescence response of Ge- and Al-doped optical fibers, its linearity, energy dependence, and sensitivity. The Ge-doped optical fibers demonstrate useful TL properties and represent an excellent candidate for use in TL dosimetry of ionizing radiation. The TL response increases monotonically over a wide photon dose range, from 0.2 Gy to 4.0 Gy. The TL results for these fibers have been compared with similar TL data for phosphor TLD-100. Commercially available Al- and Ge-doped optical fibers have both been found to yield a linear dose-TL signal relationship, although the Al-doped fiber provides only 5 % of the sensitivity of the Ge-doped fibers. The TL characteristics of Ge-doped optical fiber, plus its small size (125 μm diameter), high flexibility, ease of handling, and low cost compared with other TL materials, make this commercial optical fiber a very promising TL material for use in medicine, industry, reactor operation, and a variety of other areas. [ABSTRACT FROM AUTHOR]

Copper-doped (0.5 mol%) and undoped potassium borate glasses have been prepared by the composition of (100-x)H3BO3 + xK2CO3, where 10 ⩽ x ⩽ 30 mol % by the traditional melting quenching method. The structural pattern of glasses with different composition has been identified by X-ray diffraction (XRD). The glow curves were analysed to determine various characterizations of the TLDs. Identification of the compositions and concentrations and effective atomic number of undoped and doped potassium borate glass was carried out using scanning electron microscope analysis (SEM). The dopant concentrations are found to be 0.25mol%, while Zeff are 11.42 and 10.48 for Cu-doped and undoped potassium borate glasses, respectively. [ABSTRACT FROM AUTHOR]

Abstract: This study was conducted to determine the concentration of natural radionuclides in the granite rocks of selected quarry sites in Johor state, Malaysia and their possible radiological effects. The activity concentrations of 238U, 232Th and 40K in the areas of study indicated varying values of 238U, 232Th and 40K. The highest values of 238U and 232Th concentrations (67±1 and 85±2Bqkg−1, respectively) were observed at Kamad Quarry (IJM), whereas the highest value of 40K concentration (722±18Bqkg−1) was detected in Kim Seng Quarry, while the values of activity concentration are lower in Hanson Quarry Products (Kulai) (25±0.5 for 238U, 24±0.5 for 232Th and 429±11 for 40K). Overall, 40K has the highest concentration in the granite rocks of the quarry sites, followed by 232Th and the least for 238U. The radium equivalent activity concentration was found in the range between 94 and 239Bqkg−1, the absorbed dose rate was found to be in the range between 47 and 112nGyh−1, and effective dose ranged from 58 to 137μSvh−1. Moreover, the internal and external hazard index values were given in results lower than unity. [Copyright &y& Elsevier]