Radionuclide Determination In Surface Water Samples By Inductively Coupled Plasma With Sector Field Mass Spectrometry (ICP-SFMS)

The determination of naturally occurring radionuclides in the environment by inductively coupled plasma mass spectrometry of high resolution (ICP-SFMS) has gained recognition over the last fifteen years, relative to the radiometric techniques, as the result of improvement in instrumental performance, sample introduction equipment and sample preparation. With the increase in instrumental sensitivity, it is now possible to measure ultratrace levels of many radioisotopes.The aim of this work was to determined the natural radionuclides (232Th, 234U, 235U and 238U) in surface water using Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS). The samples were sampling from Lerma river, State of Mexico at february to april 2015. The process of treatment of sample consisted in perform an acid digestion according to the 3015A USEPA method followed of the direct measurement in ICP-SFMS. Results obtained were: a) identify the presence of 232Th, 234U, 235U and 238U isotopes in water, b) isotopic ratios were for 234U/238U=1.133 ± 0.016. ICP-SFMS has gained popularity in the field of radiochemistry, particularly as a method of detection for long lived-actinides

Applied Radiation and Isotopes Monte Carlo Verification of Output Correction Factors for a TrueBeam STx linac

The recent publication of the new code of practice IEAA/AAPM TRS-483 introduces the use of output correction factors to correct the changes in detector response in relative dosimetry of small photon beams. In TRS-483, average correction factors are reported for several detectors at 6 and 10 MV with and without attening. These correction factors were determined by Monte Carlo simulation or experimental measurements using several linacs of di erent brands and vendors. The goal of this work was to validate the output correction factors reported in TRS-483 for a 6 MV (with and without attening lter) of a TrueBeam STx® linac with Monte Carlo simulation for four radiation detectors employed in the dosimetry of small photon beams and whose output correction factors were determined using di erent radiation source than TrueBeam STx®: PTW®31010, PTW®31016, IBA®CC-01, and IBA®SFD. The results show that Monte Carlo calculated output factors, and those reported in the code of practice TRS-483 fully agree within 1%. The use of generic correction factors for a TrueBeam STx® and the detectors studied in this work is adequate for small dosimetry static beams within the uncertainties of Monte Carlo calculations and output correction factors reported in TRS-483. Key words: TRS-483, Monte Carlo simulation, output correction factors, detector model, Phase Space File, Latent Varianc

Implementación de una red Modbus con Labview

En la siguiente monografía se presenta una de las soluciones para la comunicación de un PC con tres APs (Autómatas Programables) o PC`s esclavos, para el monitoreo de esta red se utilizara el protocolo de comunicaciones Modbus. En el primer capítulo se describen las características generales del protocolo Modbus, como, modos de transmisión (RTU, ASCII), funciones más comunes del protocolo que van a ser implementadas en el programa, etc. En el capitulo dos se hace una descripción de la implementación del protocolo Modbus en Labview, se hace también un análisis de las tramas que se envían y se reciben. En el capítulo tres se describe las redes seriales que se van a utilizar (RS 232 y RS 485), una comparación entre estas y también se describe un conversor de estándar RS232 a RS 485 necesario para implementar el bus. En el cuarto capítulo se describen las Tramas que envía el PC maestro como aplicación a los tres PCs esclavos o APs, este capítulo también habla acerca de la aplicación en Labview y los Drivers de comunicación, aquí se presenta un análisis de las librerías de Modbus. Por ultimo en el capítulo quinto se dan análisis de resultados y conclusiones de acuerdo a los resultados obtenidos

DeepToF: Off-the-shelf real-time correction of multipath interference in time-of-flight imaging

Time-of-flight (ToF) imaging has become a widespread technique for depth estimation, allowing affordable off-the-shelf cameras to provide depth maps in real time. However, multipath interference (MPI) resulting from indirect illumination significantly degrades the captured depth. Most previous works have tried to solve this problem by means of complex hardware modifications or costly computations. In this work, we avoid these approaches and propose a new technique to correct errors in depth caused by MPI, which requires no camera modifications and takes just 10 milliseconds per frame. Our observations about the nature of MPI suggest that most of its information is available in image space; this allows us to formulate the depth imaging process as a spatially-varying convolution and use a convolutional neural network to correct MPI errors. Since the input and output data present similar structure, we base our network on an autoencoder, which we train in two stages. First, we use the encoder (convolution filters) to learn a suitable basis to represent MPI-corrupted depth images; then, we train the decoder (deconvolution filters) to correct depth from synthetic scenes, generated by using a physically-based, time-resolved renderer. This approach allows us to tackle a key problem in ToF, the lack of ground-truth data, by using a large-scale captured training set with MPI-corrupted depth to train the encoder, and a smaller synthetic training set with ground truth depth to train the decoder stage of the network. We demonstrate and validate our method on both synthetic and real complex scenarios, using an off-the-shelf ToF camera, and with only the captured, incorrect depth as input

Эффективность и результативность дистанционного обучения

В докладе обсуждаются вопросы эффективности и результативности дистанционного обучения в Беларуси

Mathematical Analysis of Inclusion Removal from Liquid Steel by Gas Bubbling in a Casting Tundish

The mechanism of inclusion removal from liquid steel by gas bubbling and bubble attachment in the tundish is complex due to the great number of variables involved, and it is even more difficult to study because of the turbulent flow conditions. The main objective of this work is to analyze and improve the understanding of the alumina inclusion removal rate by bubble attachment and by gas bubbling fluid dynamics effects. The results show that the inclusion collection probability mainly depends on the attachment mechanism by collision. This parameter was determined by calculating the induction time, which is shorter when the rupture time and the formation time of a stable three phases contact (particle/liquid/gas) are ignored than when it is fully considered, affecting the attachment probability. In addition, to achieve acceptable inclusion removal, a smaller bubble diameter is required, such as 1 mm. This consideration is almost impossible to achieve during tundish operation; a more realistic bubble diameter around 10 mm is employed, resulting in a very inefficient inclusion removal process by bubble attachment. Nevertheless, in a real casting tundish the inclusion removal rate employing argon bubbling is efficient; is mainly due to the fluid flow pattern changes rather than bubble attachment. Consequently, it is imperative to consider the summation of both removal mechanisms to compute a better approximation of this important operation

LanderPick, a Remote Operated Trawled Vehicle to cost-effectively deploy and recover lightweight oceanographic landers

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