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1.
Photochem Photobiol Sci ; 14(6): 1110-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25909244

RESUMO

Bismuth oxide thin films were obtained by the spray pyrolysis method using bismuth acetate as the precursor salt. The films were characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), UV-vis diffuse reflectance, X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM). The XRD patterns indicated that the pure ß phase is obtained at 450 °C and was also confirmed by FTIR. This phase presents a nanoplate morphology which is adequate for the photocatalytic reactions. Moreover, the band gap value was 2.6 eV indicating a good capacity of visible light absorption. The photocatalytic degradation of the Methyl Orange (MO) dye was pH dependent, an acid solution being easier to degrade. However, the Bi2O3 films were easily converted into BiOCl when they were in contact with a solution containing HCl. In order to preserve the ß-Bi2O3 phase, the Acid Blue 113 dye with its natural pH of 8 was used to evaluate the stability of the photocatalytic activity after five degradation cycles. The photoactivity was practically stable indicating a good performance of the material. This encouraged us to test the films in a continuous flow solar reactor prototype for the degradation of the dye solution using sunlight radiation exclusively. The good performance of the ß-Bi2O3 films indicates that they can be used for sustainable water treatment applications.

2.
Br J Nutr ; 106(10): 1506-13, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21736788

RESUMO

A total of sixty surgically castrated male pigs (Large White × Landrace) weighing 31·2 (sd 4·3) kg were used in a randomised block experiment to examine the effect of added dietary inulin (0, 20, 40 and 80 g/kg) on the occurrence of swine dysentery (SD) and on fermentation characteristics in the large intestine after experimental challenge with the causative spirochaete Brachyspira hyodysenteriae. The pigs were allowed to adapt to the diets for 2 weeks before each pig was challenged orally four times with a broth culture containing B. hyodysenteriae on consecutive days. Increasing dietary levels of inulin linearly (P = 0·001) reduced the risk of pigs developing SD; however, eight out of fifteen pigs fed the diet with 80 g/kg inulin still developed the disease. The pH values in the caecum (P = 0·072) tended to decrease, and in the upper colon, the pH values did decrease (P = 0·047) linearly with increasing inulin levels in the diets, most probably due to a linear increase in the concentration of total volatile fatty acids in the caecum (P = 0·018), upper colon (P = 0·001) and lower colon (P = 0·013). In addition, there was a linear reduction in the proportion of the branched-chain fatty acids isobutyric acid and isovaleric acid in the caecum (P = 0·015 and 0·026) and upper colon (P = 0·011 and 0·013) with increasing levels of dietary inulin. In conclusion, the present study showed that a diet supplemented with a high level of inulin (80 g/kg) but not lower levels reduced the risk of pigs developing SD, possibly acting through a modification of the microbial fermentation patterns in the large intestine.


Assuntos
Brachyspira hyodysenteriae/patogenicidade , Carboidratos da Dieta/administração & dosagem , Disenteria/prevenção & controle , Inulina/administração & dosagem , Doenças dos Suínos/prevenção & controle , Animais , Disenteria/epidemiologia , Disenteria/microbiologia , Incidência , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/microbiologia
3.
J Phys Chem B ; 114(12): 4271-5, 2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-20205443

RESUMO

In this work, we report the physicochemical properties of a variety of aliphatic phosphonium iodide (API) salts, including thermal degradation. Also, we compared the conductivity, viscosity, and fragility behavior of APIs to similar molten systems and related these properties to their structure. Our investigation has found that APIs have an intermediate fragility behavior. We plotted the conductivity and viscosity data of APIs according to Walden's rule and found that they can be classified as an associated ionic liquid (AIL), an intermediate between a true ionic liquid and a molecular species. Lastly, we correlated the structure and behavior of APIs and similar polarizable anions, such as the diacetamide anion.

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