Evaluation of residence time on nitrogen oxides removal in non-thermal plasma reactor

Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore,between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode

Bovine milk powder adulteration with vegetable oils or fats revealed by MALDI-QTOF MS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Matrix-assisted laser desorption/ionisation-quadrupole time of flight mass spectrometry (MALDI-QTOF MS) allowed detection of bovine milk powder adulteration with vegetable oils or fats with high speed and reliability, requiring little sample preparation (n-hexane extraction) and no prior separation procedures. This technique was also able to identify the adulterated employed in this fraud. Hydrogenated soybean oil addition in bovine milk powder sample generate a similar TAG profile to that observed on adulterated milk samples apprehended by the Brazilian Federal Police. In this sense, a robust method for high throughput forensic screening of milk powder adulteration by exogenous oils and fats is showed. (C) 2011 Elsevier Ltd. All rights reserved.1312722726Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Fingerprinting and aging of ink by easy ambient sonic-spray ionization mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Using easy ambient sonic-spray ionization mass spectrometry (EASI-MS), fast and non-destructive fingerprinting identification and aging of ballpoint pen ink writings have been performed directly from paper surfaces under ordinary ambient conditions. EASI-MS data obtained directly from the ink lines showed that pens from different brands provide typical ink chemical profiles. Accelerated ink aging has also been monitored by EASI-MS revealing contrasting degradation behaviors for six different common ink dyes. As demonstrated for Basic Violet 3, some dyes display a cascade of degradation products whose abundances increase linearly with time thus functioning as 'chemical clocks' for ink aging. Analysis of questionable documents has confirmed the ink aging capabilities of EASI-MS. The order of superimposition at a crossing point has also been determined by EASI-MS. For two superimposed ink lines, continuous EASI-MS analysis has also shown that the EASI spray is able to penetrate through the layers and therefore both ink layers could be characterized.1354745750Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Whisky analysis by electrospray ionization-Fourier transform mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Electrospray ionization (ESI) coupled to ultra-high resolution and accuracy Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed for the direct analysis of whisky samples. No pre-separation or extraction steps were employed and, owing to the gentleness of ESI, characteristic profiles of polar constituents of authentic whiskies from five different brands were obtained, which greatly contrast to those of counterfeit samples. Owing to the accuracy of FT-ICR MS mass measurements, elemental composition of the main ions detected were also securely determined, and related to a series of carboxylic acids, phenols, saccharides, fat acids and sulfur or nitrogen constituents of whisky. The accurate mass measurements and the number of detected ions, together with the direct, no sample preparation procedure employed, make FT-ICR MS a highly reliable approach to fingerprint whisky and to control its quality, and to screen for aging, counterfeiting and adulteration at the molecular level. (C) 2012 Elsevier Ltd. All rights reserved.51198106Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)PetrobrasFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Instantaneous chemical profiles of banknotes by ambient mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Using two desorption/ionization techniques (DESI and EASI) and Brazilian real, US$ dollar, and euro bills as proof-of-principle techniques and samples, direct analysis by ambient mass spectrometry is shown to function as an instantaneous, reproducible, and non-destructive method for chemical analysis of banknotes. Characteristic chemical profiles were observed for the authentic bills and for the counterfeit bills made using different printing processes (inkjet, laserjet, phaser and off-set printers). Detection of real-world counterfeit bills and identification of the counterfeiting method has also been demonstrated. Chemically selective 2D imaging of banknotes has also been used to confirm counterfeiting. The nature of some key diagnostic ions has also been investigated via high accuracy FTMS measurements. The general applicability of ambient MS analysis for anti-counterfeiting strategies particularly via the use of 'invisible ink' markers is discussed.1351025332539Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Brazilian Research foundation FINEPUS National Science Foundation [CHE 0848650]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)US National Science Foundation [CHE 0848650