RESUMO
This work presents the development of a cavity ring-down spectrometer (CRDS) designed for the detection of several molecules relevant for air pollution, including the second overtone of ro-vibration transitions from CO at 1.58 µm and NO at 1.79 µm. A unique feature of this CRDS is the use of custom mirrors with a reflectivity of about 99.99% from 1.52 to 1.80 µm, enabling efficient laser coupling into the cavity while ensuring a minimum detectable absorbance of 1.1 × 10-10 cm-1 within an integration time of about 1.2 s. In this work, the successful implementation of the current CRDS is demonstrated in two different wavelength regions. At 1.79 µm, the transitions R17.5 and R4.5 of the second overtone of NO are detected. At 1.58 µm, carbon dioxide and water vapor from untreated ambient air are measured, serving as an example to investigate the suitability of a post-processing procedure for the determination of the molar fraction in a multi-species composition. This post-processing procedure has the benefit of being calibration-free and SI-traceable. Additionally, CRDS measurements of gas mixtures containing CO and CO2 are also shown. In the future, the advantages of the developed cavity ring-down spectrometer will be exploited in order to perform fundamental studies on the transport processes of heterogeneous catalysis by locally resolving the gas phase near a working catalytic surface. The possibility to cover a broad wavelength region with this CRDS opens up the opportunity to investigate different catalytic reactions, including CO oxidation and NO reduction.
RESUMO
Childhood obesity increases susceptibility to musculoskeletal injuries. The purpose of this study was to describe the prevalence of overweight and obesity and to identify differences in posture and musculoskeletal pain among eutrophic, overweight, and obese students. Participants were 420 students, 252 (60%) were females and 168 males (40%), with a mean age of 11.1 (±2.3) years. The posture of all participants was qualitatively assessed; the quantitative postural evaluation was performed using the Postural Assessment Software (PAS/SAPo) for a population subsample of 99 participants. An adapted version of the Nordic Musculoskeletal Questionnaire was used for pain assessment. Data were analyzed descriptively and via statistical tests (significance level of p<0.05). The target population exhibited 22.1% of overweight individuals and 14.1% of obese. Compared to the eutrophic students, the postural evaluation showed a higher knee valgus angle, higher incidence of thoracic kyphosis, and greater prevalence of lumbar hyperlordosis in overweight and obese students (p≤0.05). No association between overweight and pain complaints was detected (p=0.994)...
A obesidade infantil aumenta a susceptibilidade a lesões musculoesqueléticas. Os objetivos deste estudo foram descrever a prevalência de sobrepeso e obesidade e identificar as diferenças na postura e dores musculoesqueléticas entre os estudantes eutróficos, com sobrepeso e obesos. Dos 420 alunos avaliados, 252 (60%) eram do sexo feminino e 168 (40%) do sexo masculino, com idade média de 11,1 (±2,3) anos. A postura de todos os indivíduos foi avaliada qualitativamente. Para uma subamostra (n=99), a avaliação postural quantitativa foi realizada pelo Software de Avaliação Postural (PAS/ SAPo). Uma versão adaptada do Questionário Nórdico de Sintomas Osteomusculares foi usada para avaliação da dor. Os dados foram analisados de forma descritiva e por testes estatísticos com nível de significância de 5%. Os resultados mostraram que a prevalência de sobrepeso foi de 22,1 % e de obesidade foi de 14,1%. Avaliação postural indicou maiores ângulos de valgo de joelho, maior incidência de cifose torácica e hiperlordose lombar em estudantes com sobrepeso e obesidade em relação aos eutróficos (p≤0,05). Não houve associação entre excesso de peso e dor (p=0,994)...
Un estudio transversal." La obesidad infantil aumenta la susceptibilidad de sufrir lesiones musculoesqueléticas. Los objetivos de este estudio es describir la prevalencia de sobrepeso y de obesidad e identificar las diferencias de postura y dolores musculoesqueléticas entre los estudiantes eutróficos, con sobrepeso y obesos. De los 420 estudiantes evaluados, 252 (60%) eran del sexo femenino y 168 (40%) del sexo masculino, con edad media de 11,1 (±2,3) años. La postura de todos los individuos fue evaluada cualitativamente. Para un submuestreo (n=99), una evaluación de la postura cuantitativa fue realizada por un Programa de Evaluación Postural (Software de Avaliação Postural PAS/SAPo). Una versión adaptada del Cuestionario Nórdico Estandarizado fue utilizada para la evaluación del dolor. Los datos han sido analizados de forma descriptiva y por testes estatísticos con nivel de significancia del 5%. Los resultados han demostrado que la prevalencia de sobrepeso fue de 22,1% y de obesidad fue de 14,1%. La evaluación de la postura ha indicado angulos más grandes de genu valgum (valgo de rodilla), mayor incidencia de cifosis torácica e hiperlordosis lumbar en estudiantes con sobrepeso y obesidad en relación a los alumnos eutróficos (p≤0,05). No hubo asociación entre el exceso de peso y el dolor (p=0,994)...
