376 research outputs found
Production of 1,3-propanediol by Clostridium butyricum VPI 3266 using a synthetic medium and raw glycerol
Growth inhibition of Clostridium butyricum
VPI 3266 by raw glycerol, obtained from the biodiesel
production process, was evaluated. C. butyricum presents
the same tolerance to raw and to commercial
glycerol, when both are of similar grade, i.e. above 87%
(w/v). A 39% increase of growth inhibition was observed
in the presence of 100 g l 1 of a lower grade raw
glycerol (65% w/v). Furthermore, 1,3-propanediol production
from two raw glycerol types (65% w/v and 92%
w/v), without any prior purification, was observed in
batch and continuous cultures, on a synthetic medium.
No significant differences were found in C. butyricum
fermentation patterns on raw and commercial glycerol
as the sole carbon source. In every case, 1,3-propanediol
yield was around 0.60 mol/mol glycerol consumed
Production of 1,3-Propanediol by Clostridium butyricum VPI 3266 in continuous cultures with high yield and productivity
The effects of dilution rate and substrate feed concentration on continuous glycerol fermentation by Clostridium butyricum VPI 3266, a natural 1,3-propanediol producer, were evaluated in this work. A high and constant 1,3-propanediol yield (around 0.65 mol/mol), close to the theoretical value, was obtained irrespective of substrate feed concentration or dilution rate.
Improvement of 1,3-propanediol volumetric productivity was achieved by increasing the dilution rate, at a fixed feed substrate concentration of 30, 60 or 70 g l-1.
Higher 1,3-propanediol final concentrations and volumetric productivities were also obtained when glycerol feed concentration was increased from 30 to 60 g l-1, at
D=0.05–0.3 h-1, and from 60–70 g l-1, at D=0.05 and 0.1 h-1. 30 g l-1 of 1,3-propanediol and the highest reported value of productivity, 10.3 g l-1 h-1, was
achieved at D=0.30 h-1 and 60 g l-1 of feed glycerol. A switch to an acetate/butyrate ratio higher than one was observed for 60 g l-1 of feed glycerol and a dilution rate
higher than 0.10 h-1; moreover, at D=0.30 h-1 3-hydroxypropionaldehyde
accumulation was observed for the first time in the fermentation broth of C. butyricum
Real-time motion-based hand gestures recognition from time-of-flight video
The final publication is available at Springer via http://dx.doi.org/10.1007/s11265-015-1090-5This paper presents an innovative solution based on Time-Of-Flight (TOF)
video technology to motion patterns detection for real-time dynamic hand gesture
recognition. The resulting system is able to detect motion-based hand gestures getting
as input depth images. The recognizable motion patterns are modeled on the basis of
the human arm anatomy and its degrees of freedom, generating a collection of synthetic
motion patterns that is compared with the captured input patterns in order to finally
classify the input gesture. For the evaluation of our system a significant collection of
gestures has been compiled, getting results for 3D pattern classification as well as a
comparison with the results using only 2D informatio
Biology of the red mullet mullus surmuletus (mullidae) off the Canary Islands, Central-East Atlantic
The biology of red mullet Mullus surmuletus was studied from collections taken off the Canary Islandsbetween January 1991 and September 1993. Total length ranged from 12 to 33 cm, mainly between 15 and 21cm. Males ranged from 14 to 26 cm and females from 14 to 33 cm. Females dominated the larger size-classes (>18 cm). The overall ratio of males to females was 1:2.3. The reproductive period extended from February toMay, spawning peaking in March and April. The total length at 50% maturity was 16.6 cm for the whole population.The length-mass relationship for all individuals can be described by the parameters a = 0.0074 and b = 3.1826. Fish aged 0.8 years were present in the samples. The parameters of the Von Bertalanffy growth equation obtained for all individuals were: L‡ = 35.71 cm and k = 0.22.year-1. Significant differences were found in the growth parameters between males and females. The rates of total mortality Z, natural mortality M and fishing mortality F were 1.25, 0.55 and 0.70.year-1 respectively. The estimated total length at first capture was 15.74 cm
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