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ABSTRACT: This paper presents an FPGA-based ultrasonic location system. This system uses low-cost FPGAs and ultrasonic transducers to provide 3-D location to mobile nodes in an indoor environment. Synchronization is reached using the radiofrequency transducers that mobile nodes usually include. FPGAs have been used to sample ultrasonics and radiofrequency inside a custom peripheral which is attached to a MicroBlaze soft-processor. The calculus of the position of the mobile node is accomplished inside this processor.
Industrial Electronics (ISIE), 2010 IEEE International Symposium on; 08/2010
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ABSTRACT: The System-on-Token architecture for biometric systems gives users full control over their biometric data and lets them sign digital transactions using biometrics. The authors implemented and tested the architecture on a commercial mobile device, the Nokia N800.
IEEE Security and Privacy Magazine 05/2010; · 0.90 Impact Factor
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ABSTRACT: This paper presents a low cost indoor ultrasonic-based positioning system. This system allows the mobile nodes of a Wireless Sensor Network to know their location using radiofrequency and ultrasonics. To achieve this goal, a matrix of transmitting anchor points is installed whereas the mobile nodes receive these transmitted signals and estimate the time-of-flight of the ultrasonic signals. Using two time-of-flight measurements and trilateration equations, the location of the mobile nodes can be inferred in a 2-D space.
Industrial Electronics, 2009. IECON '09. 35th Annual Conference of IEEE; 12/2009
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ABSTRACT: The kinetics of ascorbic acid (AA) loss during storage of packed table olives with two different levels of added AA was investigated. Three selected storage temperatures were assayed: 10 degrees C, ambient (20-24 degrees C), and 40 degrees C. The study was carried out in both pasteurized and unpasteurized product. The effect of pasteurization treatment alone on added AA was not significant. In the pasteurized product, in general AA degraded following a first-order kinetics. The activation energy calculated by using the Arrhenius model averaged 9 kcal/mol. For each storage temperature, the increase in initial AA concentration significantly decreased the AA degradation rate. In the unpasteurized product, AA was not detected after 20 days in samples stored at room temperature and AA degradation followed zero-order kinetics at 10 degrees C, whereas at 40 degrees C a second-order reaction showed the best fit. In both pasteurized and unpasteurized product, the low level of initial dehydroascorbic acid disappeared during storage. Furfural appeared to be formed during storage, mainly at 40 degrees C, following zero-order kinetics.
Journal of Agricultural and Food Chemistry 04/2006; 54(6):2206-10. · 2.82 Impact Factor
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Grasas y Aceites. 01/2002;
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ABSTRACT: Inoculation at alkaline pH (above 9) of lye-treated green olives with starter cultures of Lactobacillus pentosus CECT 5138 was studied. Despite an initial loss of viability in the order of 1-2 log cycles on average, depending mainly on time of application, cultures grew and initiated an accelerated fermentation process. Inoculation reduced the population of Enterobacteriaceae, and thereby potential spoilage, and produced a quicker acidification of brines and decrease of pH, when compared with control uninoculated batches. Results obtained throughout three consecutive seasons demonstrated that utilization at high pH of starter cultures of lactobacilli is feasible, provided that the inoculum size takes into account the initial low survival.
International Journal of Food Microbiology 08/2001; 67(1-2):115-22. · 3.33 Impact Factor
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ABSTRACT: Changes in physicochemical characteristics, substrate depletion, and product formation during fermentation were followed in both brine and olive juice in order to achieve a complete knowledge of fermentation chemistry in Spanish-type green olives. Both spontaneous and controlled fermentations were investigated. Fermentation rate, irrespective of the type of fermentation, was lower in olive juice than in brine, but the main acid products eventually reached equilibrium. Final free acidity remained significantly (p < 0.05) higher, and combined acidity remained lower, in brine than in olive juice in both fermentations, but differences in final pH were not significant in controlled fermentation. Final concentrations of lactic and formic acids were significantly (p < 0. 05) higher, and those of ethanol and succinic acid were lower, in controlled fermentation than in spontaneous fermentation. Butanediol, attributable to Enterobacteriaceae growth, was formed only in the latter case. Calculated carbon recoveries were not significantly (p < 0.05) different in any case, giving a mean of some 78%.
Journal of Agricultural and Food Chemistry 01/2001; 48(12):5975-80. · 2.82 Impact Factor
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Grasas y Aceites. 01/2001;
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A. Heredia Moreno,
P. García García,
M. Brenes Balbuena, A. de Castro,
F. J.G. Muriana,
R. Borja Padilla,
Mª. C. Durán Quintana,
A. Garrido Fernández,
R. Zamora,
F. J. Hidalgo,
J. Velasco Jiménez
Grasas y Aceites. 01/2000;
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M.ª C. Duran Quintana,
E. Graciani,
F. J. Hidalgo,
R. Zamora,
J. L. Ruiz Barba,
A. G. Pérez Rubio,
A. Garrido Fernández, A. de Castro,
J. Vioque,
M. Brenes Balbuena,
M Alaiz,
W. Moreda Martine
Grasas y Aceites. 01/1999;
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ABSTRACT: The controlled fermentation of peeled, blanched garlic, using a starter culture of Lactobacillus plantarum, was studied and compared with that of unblanched garlic. Blanching was carried out in hot water (90 degrees C) for 15 min. The starter grew abundantly in the case of blanched garlic, producing mainly lactic acid and reaching a pH of 3.8 after 7 days, but its growth was inhibited in unblanched garlic. Ethanol and fructose, coming from enzymatic activities of the garlic, and a green pigment were formed during the fermentation of unblanched garlic, but not of blanched garlic. The blanched garlic fermented by L. plantarum, even without a preservation treatment (pasteurization), was microbiologically stable during storage at 30 degrees C in an acidified brine (approximately 3% (w/w) NaCl and pH 3.5 at equilibrium), but fructans were hydrolyzed. The packed fermented product and that obtained by direct packing without fermentation were not significantly different with regard to flavour.
International Journal of Food Microbiology 03/1998; 39(3):205-11. · 3.33 Impact Factor
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Grasas y Aceites. 01/1998;
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ABSTRACT: A mixed culture of Lactobacillus plantarum and Saccharomyces cerevisiae was compared with a single culture of L. plantarum as starter for the fermentation of lye-treated carrots. Using the mixed culture, more than 95% of glucose, fructose and malic acid was consumed after 7 days of fermentation in a brine containing 2.5% w/v NaCl and 0.7% acetic acid, but only 54% of sucrose was degraded. The fermentation products quantified were lactic acid, ethanol and acetic acid and carbon recovery was 88%. Using the single culture of L. plantarum, substrate consumption was lower, and carbon recovery almost 100%. In uninoculated lye-treated carrots, heterofermentative bacteria grew, with the production of considerable amounts of mannitol. In all cases, the stability, sensorial characteristics and carotenoid content of the packed product were studied during 9 months of storage at 30 degrees C, and two different preservation systems were compared: addition of preservatives, approximately 500 and 1000 mg/kg of sorbic and benzoic acid, respectively, and pasteurization at 80 degrees C for 10 min. The pasteurized samples were microbiologically stable during the storage period, while lactic acid bacteria grew in the samples with preservatives. Storage time significantly (P < 0.05) affected the texture and colour parameters (L*, a*, b*) of the carrots, but not the amounts of alpha- and beta-carotene. The type of fermentation had no significant effect on texture, colour parameters or carotenoid content. The preservation method had no significant effect on texture or carotenoid content, but did affect colour (parameter a*). The flavour of carrots fermented by the mixed culture was significantly (P < 0.05) preferred to that of those fermented with a single culture of L. plantarum.
International Journal of Food Microbiology 04/1997; 35(1):83-90. · 3.33 Impact Factor
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R Guillén,
J. S, A. de Castro,
A. Heredia,
R. Zamora,
F. J. Hidalgo,
P. García García,
M. Brenes Balbuena,
C. Gómez Herrera,
A. Garrido Fernández,
M. J. Martín Polvillo,
L Rejano
Grasas y Aceites. 01/1997;
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A. Garrido Fernández,
A. Heredia,
W. Moreda Martino,
A. Cert, A. de Castro,
M. J. Martín Polvillo,
M. V. Ruiz Méndez,
F. J. Hidalgo,
R. Zamora,
C. Gómez Herrera,
M. Brenes Balbuena
Grasas y Aceites. 01/1996;
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Grasas y Aceites. 01/1995;
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A. de Castro,
M. V. Ruiz Méndez,
C. Gómez Herrera,
A. Garrido Fernández,
M. Brenes Balbuena,
C Sanz,
A. H. Sánchez Gómez,
J. L. Ruiz Barba,
R. Zamora,
F. J. Hidalgo,
A. Montano,
J. A. Cayuela Sánchez,
T. Coronil Jiménez
Grasas y Aceites. 01/1995;
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A. Garrido Fernández,
C. Gómez Herrera,
P. García García,
M. V. Alonso García,
A. H. Sánchez Gómez,
A. Guinda,
A. Heredia Moreno,
R. Zamora,
A Garrido,
F. J. Hidalgo, A. de Castro,
J. C. González Vázquez,
G. Márquez-Ruiz
Grasas y Aceites. 01/1994;
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Grasas y Aceites. 01/1994;
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ABSTRACT: Different topics dealing with vegetable products fermentation, from manufacturing to microorganisms, and their growth factors, are reviewed. The main pathways for sugar metabolism and degradation reactions of organic and amino acids are described, as well as their influence on sensorial characteristics of the final product. A thorough research on several areas is considered mandatory, in order to increase the value of fermented vegetable foods.Se revisan los diferentes aspectos relacionados con la fermentación de productos vegetales, desde los procesos de elaboración a los microorganismos responsables y los factores que afectan a su desarrollo. Se presentan, asimismo, las principales reacciones metabólicas de degradación de azúcares y ácidos orgánicos que tienen lugar en los medios de fermentación, así como la influencia de éstas y otras reacciones sobre las características sensoriales del producto elaborado. Finalmente, se citan algunas de las áreas de investigación en las que se considera habría que profundizar para una mayor valoración de los alimentos vegetales fermentados.
Grasas y Aceites. 01/1992;
