Search

Your search keyword '"Jorge, L. M. M."' showing total 43 results
Start Over Author "Jorge, L. M. M."
43 results on '"Jorge, L. M. M."'

35. TiO2 and modified TiO2 /Fe on photocatalytic reduction of Hg2+ using artificial and solar radiation.

Author

Coelho, A. L. S., de Almeida Neto, A. F., Ivashita, F. F., Lenzi, G. G., Jorge, L. M. M., and dos Santos, O. A. A.

Subjects
PHOTOREDUCTION, SOLAR radiation, MOSSBAUER spectroscopy, FOURIER transform infrared spectroscopy, SOLAR stills, POINTS of zero charge, SOLAR collectors
Abstract

Mercury is a highly hazardous water contaminant; both organic and inorganic forms are cumulatively and extremely toxic. In this context, this study describes the application of TiO2 -based systems modified with 5, 8, 10 and 15 wt% Fe using the impregnation method for the photocatalytic reduction of Hg2+. Characterization of TiO2 and synthesized materials was performed by using Brunauer, Emmett and Taller area, pore diameter and pore volume, scanning electron microscopy, point zero charge, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, photoacoustic and Mössbauer spectroscopy. The photocatalytic reduction of Hg2+ was performed in batch stirred tank reactor and compound parabolic collector solar photoreactor, in the presence of catalysts, under four different reaction conditions. The process of heterogeneous photocatalysis was studied in the treatment of synthetic wastewater containing mercury chloride (HgCl2 ) in different reaction conditions. In particular, the influence of oxygen and formic acid was analyzed. The results showed that an addition of 8% to the iron weight improved the performance of the photocatalytic titania in the reduction of Hg2+ (artificial radiation). In the presence of this catalyst, and reaction medium containing only mercuric chloride in an aqueous solution containing oxygen, Hg2+ was 100% reduced, after 3 h of reaction. However, under solar radiation, the reduction of Hg2+ obtained was 67%. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

36. Estimation of effective grain thermal properties in a fixed bed dryer

Author

Fregolente,L. V., Santos,O. A. A., and Jorge,L. M. M.

Subjects
secagem de grãos, grain drying, fixed bed, leito fixo, propriedades térmicas efetivas, effective thermal properties
Abstract

A secagem de grãos em leito fixo é um processo complexo, ocorrendo simultaneamente a transferência de calor e de massa, dificultando a estimativa dos parâmetros térmicos efetivos, pois estes podem sofrer variações significativas no decorrer da secagem em função de alterações no teor de umidade. Neste trabalho, este problema foi contornado estimando-se os parâmetros térmicos efetivos no final da secagem, quando o teor de umidade dos grãos que compõem o leito alcança valores de equilíbrio, deixando de existir a transferência de massa, persistindo apenas a transferência de calor em regime permanente. Nestas condições, o leito possui um teor de umidade constante e a estimativa dos parâmetros térmicos efetivos pode ser efetuada a partir do ajuste de um modelo pseudo-homogêneo bidimensional estático à várias medidas de temperatura no leito de grãos no final da secagem. Os resultados indicam que a estratégia utilizada para estimativa da condutividade térmica efetiva radial e do coeficiente efetivo de transferência de calor parede-leito foi adequada. Além do que, constatou-se que dentre os grãos estudados - soja, feijão, milho e trigo - a soja apresenta os menores valores de condutividade efetiva radial, enquanto o trigo apresenta o maior valor do coeficiente de transferência de calor parede-leito. Fixed bed grain drying is a complex process, where mass and heat transfer occur simultaneously, complicating the estimation of the effective thermal parameters, because they can go through significant variations along the drying process, due to moisture content variations. In this work, this problem was avoided by estimating the effective thermal parameters at the end of the drying process, when the grain moisture content reaches equilibrium, and mass transfer stops, persisting only the steady state heat transfer. In these conditions, the bed has a constant moisture content and the estimation of the effective thermal parameters can be obtained from the adjustment of a steadystate two-dimensional pseudohomogeneous model to several fixed bed temperature measurements at the end of the drying process. The results show that the strategy used to evaluate the effective thermal conductivity and the effective wall heat transfer coefficient was appropriate. In addition, among the grains analysed - soy, bean, corn and wheat-, soy presents the smallest values of effective radial conductivity, while wheat presents the greatest effective wall heat transfer value.

Published
2004

43. Analysis of electromyographic muscles activity of gait in healthy subjects with and without AFO developed for patients with hemiparesis.

Author

Costal RV, Rosa AA, Santana TA, Jorge LM, Corrêa FI, Corrêa JC, and Oliveira CS

Subjects
Adolescent, Adult, Electromyography, Female, Humans, Male, Paresis rehabilitation, Statistics, Nonparametric, Foot physiology, Gait physiology, Orthotic Devices, Paresis physiopathology
Abstract

The aim of the present study was to analyze the electromyographic (EMG) signals of the rectus femoris (RF), vastus lateralis (VL), tibialis anterior (TA) and soleus (SO) muscles in young healthy adults with and without the use of an experimental ankle-foot-orthosis (AFO) designed for patients with hemiparesis. Twenty-eight individuals with an average age of 22 +/- 3.63 years participated in the study. An electromyograph, surface electrodes and two force plates were used. There was a non-significant increase in the TA activity with the use of the AFO (6.04 +/- 2.81) when compared to non-use (5.91 +/- 2.49) (p > 0.5); the same was true for the other muscles evaluated. There was a positive correlation (r = 0.37) between TA and SO activity (p < 0.05). The results demonstrate that the AFO did not affect the gait pattern of healthy young adults.

Published
2010

Catalog

Books, media, physical & digital resources
See catalog results