Search results for "Nuclear engineering"
showing 10 items of 533 documents
Target Cooling Options for Neutron Sources at High Power Densities
2014
Abstract Compact neutron sources in many cases beat large ones when it comes to power density; thus, many issues concerning cooling are shared, and each party can learn a lot from the other facilities. Starting from accrued experience with water cooling at moderate power densities in SINQ over the last 15 years, a brief overview will be attempted showing the relevant parameters and specific approaches at several existing and planned neutron (spallation) sources. Extensions from the established ground of cooling with water will be sketched in two directions. An outline of an experiment planned for freshly determining in a representative geometry the hard limit for water cooling, i.e. full bo…
A Cooperative Multi-Agent System for Crowd Sensing Based Estimation in Smart Cities
2020
The concept of Smart City has spread as a solution to ensure better access to information and services to citizens, but also as a means to reduce the environmental footprint of cities. To this end, a continuous and wide observation of the environment is necessary to analyze information that enables government bodies to act on the environment appropriately. Moreover, a diffused acquisition of information requires adequate infrastructure and proper devices, which results in relevant installation and maintenance costs. Our proposal enables reducing the number of necessary sensors to be deployed while ensuring that information is available at any time and anywhere. We present the HybridIoT syst…
Comparative Surface Morphology, Chemical Composition, and Cytocompatibility of Bio-C Repair, Biodentine, and ProRoot MTA on hDPCs
2020
Biocompatibility is an essential property for any vital pulp material that may interact with the dental pulp tissues. Accordingly, this study aimed to compare the chemical composition and ultrastructural morphology of Biodentine (Septodont, Saint Maur-des-Fosses, France), ProRoot MTA (Dentsply Tulsa Dental Specialties, Johnson City, TN, USA), and Bio-C Repair (Angelus, Londrina, PR, Brazil), as well as their biological effects on human dental pulp cells. Chemical element characterization of the materials was undertaken using scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX). The cytotoxicity was assessed by analyzing the cell viability (MTT assay), cell morphology …
ANÁLISIS DE LA DIVERSIDAD EN MATERIALES DIDÁCTICOS DE EDUCACIÓN PRIMARIA
2021
El objetivo de este análisis fue detectar la presencia o no de la diversidad en las imágenes de materiales didácticos realizando un estudio de tipo descriptivo y comparativo entre los diferentes materiales. La muestra recogió 66 materiales didácticos. Los resultados obtenidos mostraron que las parejas homosexuales son excluidas de las imágenes y que se proyecta una visión estereotipada tanto de la discapacidad como de la etnia llegando a la discriminación de alguna de ellas. Es por ello por lo que consideramos la necesidad de concienciar sobre la importancia de las imágenes de los materiales didácticos y, de esta manera, identificar y eliminar los estereotipos que se están transmitiendo. Th…
Analysis of radionuclide concentration in air released through the stack of a radiopharmaceutical production facility based on a medical cyclotron
2015
Abstract Positron emitting radionuclides are increasingly used in medical diagnostics and the number of radiopharmaceutical production facilities have been estimated to be growing worldwide. During the process of production and/or patient administration of radiopharmaceuticals, an amount of these radionuclides might become airborne and escape into the environment. Therefore, the analysis of radionuclide concentration in the air released to the stack is a very important issue to evaluate the dose to the population living around the plant. To this end, sampling and measurement of radionuclide concentration in air released through the stack of a Nuclear Medicine Center (NMC), provided with a c…
Eumelanin Coating of Silica Aerogel by Supercritical Carbon Dioxide Deposition of a 5,6-Dihydroxyindole Thin Film
2018
Eumelanin integration in silica aerogel (SA) was achieved via supercritical adsorption of 5,6-dyhydroxyindole (DHI) from CO2. Notably, after the supercritical treatment, DHI evolved towards spontaneous polymerization, which resulted in uniform pigment development over the SA. The new material was characterized for its morphological and physicochemical properties, disclosing the formation of a eumelanin-like coating, as confirmed by UV&ndash
The Influence of Student Abilities and High School on Student Growth: A Case Study of Chinese National College Entrance Exam
2019
Enabled by available educational data and data mining techniques, educational data analysis has become a hot topic. Current researches mainly focus on the prediction of problems and performance rather than revealing the underlying causal relationships. Based on a unique exam data, we extracted the abilities of examinee from HSEE (High School Entrance Exam) based on the knowledge of educational experts, then we measured student growth from middle school to high school in total score and subject scores. We studied the impact of high school ranking and student abilities of HSEE on student growth by multiple linear regression model, in which high school ranking is divided into 5 levels, Level 1…
Fuzzy Systems Based on Multispecies PSO Method in Spatial Analysis
2012
We present a method by using the hierarchical cluster-based Multispecies particle swarm optimization to generate a fuzzy system of Takagi-Sugeno-Kang type encapsulated in a geographical information system considered as environmental decision support for spatial analysis. We consider a spatial area partitioned in subzones: the data measured in each subzone are used to extract a fuzzy rule set of above mentioned type. We adopt a similarity index (greater than a specific threshold) for comparing fuzzy systems generated for adjacent subzones.
Bone-Healing Pattern on the Surface of Titanium Implants at Cortical and Marrow Compartments in Two Topographic Sites: an Experimental Study in Rabbi…
2018
This study evaluates the bone-healing patterns on the surface of titanium implants at the cortical and marrow compartments of bicortically-installed implants in the diaphysis and metaphysis of rabbit tibiae. In 27 New Zealand rabbits, two implants, one for each macro-design and with equal resorbable blasted media (RBM) implant surfaces, were randomly implanted in the diaphysis or metaphysis of each tibia. The flaps were sutured to allow submerged healing. The animals were sacrificed after two, four, or eight weeks, with nine weeks used for the period of healing. Ground sections were prepared and analyzed. No statistically significant differences were found between the two groups for newly f…
Characterization of Rabbit Mesenchymal Cell Attachment on Calcium Phosphate Surface
2014
In the current study, the effect of three different treated surfaces of hydroxyapatite and β-tricalcium phosphate on mesenchymal cell attachment has been investigated. Calcium phosphate powders have been synthesized, uniaxially pressed, polished and sintered. Mesenchymal cells have been seeded onto unpolished, polished and polished-thermally etched ceramic samples. The ceramic samples have been characterized by XRD, FTIR and SEM. Results have shown that the best cell attachment and morphology are on the unpolished surface indicating that relatively rough surface is better for cell application.