Implantação do curso de técnico em ótica na modalidade de educação à distância EAD

Orientador : Ricardo Antunes de SáMonografia (especialização) - Universidade Federal do Paraná, Setor de Educação, Curso de Especialização em Educação à Distância.Inclui referências

Implantação do curso de técnico em ótica na modalidade de educação à distância EAD

Orientador : Ricardo Antunes de SáMonografia (especialização) - Universidade Federal do Paraná, Setor de Educação, Curso de Especialização em Educação à Distância.Inclui referências

OBTENÇÃO DE SENSORES DE TEMPERATURA DO TIPO NTC A PARTIR DE MISTURA MECÂNICA DE ÓXIDOS DE NÍQUEL E COBALTO

No presente trabalho foi caracterizada a microestrutura e os parâmetros elétricos de sensores de temperatura do tipo NTC, a partir de mistura mecânica de óxidos de níquel e cobalto. Foram preparadas diferentes composições ( em mol ) entre os dois materiais e sinterizados nas temperaturas de 1150, 1200, 1250 e 1300C. A microestrutura foi caracterizada pela técnica de raios X, por MEV e EDS, no que se refere às fases formadas durante a sinterização, assim como, com respeito ao tamanho de grão, distribuição dos elementos e da porosidade do corpo cerâmico final. Para as composições de 10, 20, 30, 40, 50, 60, 80 e 90 em mol de NiO em C3O4, e sinterizadas nas quatro temperaturas, obteve-se a formação de soluções sólidas entre os óxidos de níquel e de cobalto. A composição de 70 em mol de NiO apresentou a formação da fase do espinélio NiC2O4, nas temperaturas de 1250 e 1300 C, com a segregação da fase de CO na região intergranular. As melhores características termistoras, obtidas pela caracterização elétrica DC, foram encontradas para a composição monofásica de 60 em mol de NiO, sinterizada a 1250C, e para a composição de 70 em mol de NiO sinterizada a 1300C. A composição de 70 de NiO apresentou uma constante termistora de 6203 K-1, sensibilidade igual a -4,0 (a 120C) e energia de ativação (Ea) para o processo de condução eletrônica de 0,53 eV.In this work it was characterized the microstructure and the electrical parameters of NTC temperature sensors, based on the mechanical mixing of niquel and cobalt oxides. Different proportions of this two materials (mol), was prepared and sintered at 1150C, 1200C, 1250C and 1300C. The microstructure was characterized by x-ray diffraction, MEV and EDS referring to the fases formed during the sintering, as well as, regarding grain size, the distribution of the chemical elements of this two oxides and the porosity of the final ceramic product. For the proportions of 10, 20, 30, 40, 50, 60, 80 e 90 (mol) of NiO on C3O4, and sintered on the four temperarures, it was obtained solid solution between niquel and cobalt oxides. Spinel phase, NiC2O4, was formed in the composition with 70 NiO (mol) at 1250C and 1300C, with segregation of CoO phase between the grain boundaries. The one phase composition with 60 (mol) NiO, sintered at 1250C, and the composition with 70 (mol) NiO, sintered at 1300C, showed the best thermistor characteristics, by DC characterization. The values of beta factor, sensitivity and activation energy for the conductivity process (Ea), of the composition with 70 NiO was respectively 6203 K-1; -4,0 at (120C) and 0,53 eV

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status