Utilization of metal and radionuclide concentrations to assess the influence of shrimp farming on the geochemical characteristics of sediments.

This article assesses the environmental impacts of aquatic biota cultivation, focusing on shrimp farming in Brazil's Northeast, as this practice has proven to be one of the main sources of economic growth in the region. For this purpose, sediment samples were collected from areas impacted and not directly impacted by shrimp farming, and concentrations of key geochemical parameters such as salinity, various elements (K, P, Cu, Mn, Pb, Zn, Al, Ca, Fe, Mg, and Na), and natural radionuclides (K-40, Ra-226 and Ra-228) were compared using statistical tools. Element concentrations were determined using ICP-OES, and naturally occurring radionuclide concentrations were obtained through gamma spectrometry.

Calibration system correction factor for measuring the reference air kerma rate (RAKR) applied to high dose rateIr sources (HDR).

The aim of this study was to use computer simulation to analyze the impact of the aluminum fixing support on the Reference Air Kerma (RAK), a physical quantity obtained in a calibration system that was experimentally developed in the Laboratory of Radiological Sciences of the University of the State of Rio de Janeiro (LCR-UERJ). Correction factors due to scattered radiation and the geometry of theIr sources were also sought to be determined. The computational simulation was validated by comparing some parameters of the experimental results with the computational results.

Environmental impact assessment due to the intake of uranium contained in surface waters in a semi-arid region in Brazil.

In Santa Quitéria City, part of the population uses surface water for potation. These waters do not undergo any treatment before consumption. As the region has a deposit of uranium, assessing water quality becomes important.

Internal dose rate due to intake of uranium and thorium by fish from a dam reservoir associated with a uranium mine in Brazil.

Uranium mining can cause environmental impacts on non-human biota around mine sites. Because of this, the reduction in non-human biota exposure becomes an important issue. Environmental radioprotection results from the evolution of human radioprotection; it is based on dose rate to non-human biota and uses, as a biological target, and has harmful effects on populations.

Assessment and estimation of the effective dose due to external exposure from natural radioactivity of sands used in civil construction in the state of Rio de Janeiro,Brazil.

The presence of naturally occurring radioactivity in sand and other building materials results in indoor and outdoor exposure to the public. Sand is one of the main components in civil construction alongside cement, crushed stone and bricks. Thus, this research was carried out in twenty sand samples with the objective of investigating the hazard indices of natural radiation, due to the presence of U, Ra, Th and K in sand samples collected in some locations in the state of Rio de Janeiro (Brazil), analyzing by gamma spectrometry and using an HPGe detector.

Radioactive gold nanocluster (198-AuNCs) showed inhibitory effects on cancer cells lines.

Cancer is a global epidemic disease responsible for over ten millions death worldwide. The early diagnosis and the precise treatment with reduced adverse reactions are the main goal worldwide. In this study, we produced, characterized and evaluated ( in three different cancer cell lines (protaste, breast and melanoma) a radioactive gold nanocluster (R-AuNC) (Au25(Capt)18).

Evaluation of the radiological quality of water released by a uranium mining in Brazil.

A mine in an area of naturally occurring radioactive materials (NORM), characterized by acid mine drainage, generates effluents with natural radionuclide concentrations, usually above the limits authorized by the regulator. The plant exploiting NORM controls the water quality and discharges it into the aquatic environment after meeting technical requirements. Downstream, water usage is unrestricted.

Equivalent dose calculation in simulation of lung cancer treatment and analysis of dose distribution profile.

Currently, lung cancer is one of the most lethal types of cancer (IARC, 2012), the pathology being detected in advanced stage, when the tumor has considerable volume because the disease in most cases asymptomatic in the early stages (INCA, 2016). Dosimetry analysis of healthy organs under real conditions is not feasible. Therefore, computational simulations are used to aid in dose verification in organs of patients submitted to radiotherapy.

Evaluation of collimator rotation for volumetric modulated arc therapy lung stereotactic body radiation therapy using flattening filter free.

The collimator in volumetric modulated arc therapy (VMAT) planning is rotated to minimize tongue-and-groove effect and interleaf leakage. The aim of this study was to evaluate the effect of collimator angle on the dosimetric results of VMAT plan for patients with lung cancer undergoing stereotactic body radiation therapy (SBRT) treatment. In the present investigation discrepancies between the calculated dose distributions with different collimators rotations have been studied.

Determination of Ra-226, Ra-228 and K-40 specific activities in samples of mineral fertilizers marketed in the city of Rio de Janeiro, Brazil.

Fertilizer samples were collected in the city of Rio de Janeiro and were analyzed using HPGe detector. The specific activities of Ra-226 ranged from 1.48 Bq/kg to 597 Bq/kg, of Ra-228 from 2.

Assessment of uranium release to the environment from a disabled uranium mine in Brazil.

The Ore Treatment Unit (in Portuguese Unidade de Tratamento de Minérios - UTM) located in Caldas, MG, Brazil is a disabled uranium mine. Environmental conditions generate acid drainage leaching metals and radionuclides from the waste rock pile. This drainage is treated to remove the heavy metals and radionuclides, before allowing the release of the effluent to the environment.

Dosimetry in Radiosynoviorthesis: 90Y VS. 153Sm.

Although there are several radionuclides suitable for radiosynoviorthesis (RSO), not all of them can irradiate deeper synovium. Yttrium-90 (Y) is the beta radionuclide with more penetration range; therefore, it is predominantly used to treat knees. The aim of this paper is to highlight several dosimetry concepts to compare Y and Sm, also discussing the feasibility of implementing a dose planning methodology for both in RSO.

Prediction of volume fractions in three-phase flows using nuclear technique and artificial neural network.

This work presents methodology based on nuclear technique and artificial neural network for volume fraction predictions in annular, stratified and homogeneous oil-water-gas regimes. Using principles of gamma-ray absorption and scattering together with an appropriate geometry, comprised of three detectors and a dual-energy gamma-ray source, it was possible to obtain data, which could be adequately correlated to the volume fractions of each phase by means of neural network. The MCNP-X code was used in order to provide the training data for the network.

Use of a bioindicator system in the study of the mutagenetical effects in the neighborhoods of deposits of radioactive waste.

The purpose of the research described in this paper was to analyze the biological mutational effects caused by low doses of ionizing radiation on biological samples placed nearby and around deposits of radioactive waste, as a way of monitoring the environment close to them. In order to do this, the plant Tradescantia pallida was chosen, and through micronuclei tests the sensitivity of the dose/response to bio-monitoring could be observed. The plants were exposed for a period of 24h in previously chosen sites around Brazil, within the proximity of nuclear waste deposits.