Search results for "Biotechnology"
showing 10 items of 5678 documents
Effect of high hydrostatic pressure on extraction of B-phycoerythrin from Porphyridium cruentum: Use of confocal microscopy and image processing
2019
International audience; The aim of the study was to extract B-phycoerythrin from Porphyridium cruentum while preserving its structure. The high hydrostatic pressure treatments were chosen as extraction technology. Different methods have been used to observe the effects of the treatment: spectrophotometry and confocal laser scanning microscopy followed by image processing analysis. Image processing led to the generation of masks used for the identification of three clusters: intra, extra and intercellular. All methods showed that high hydrostatic pressure treatments between 50 and 500 MPa failed to extract B-phycoerythrin from Porphyridium cruentum cells. The fluorescence emission was negati…
Optimization of 3-DOF Parallel Motion Devices for Low-Cost Vehicle Simulators
2017
Motion generation systems are becoming increasingly important in certain Virtual Reality (VR) applications, such as vehicle simulators. This paper deals with the analysis of the Inverse Kinematics (IK) and the reachable workspace of a three-degrees-of-freedom (3-DOF) parallel manipulator, proposing different transformations and optimizations in order to simplify its use with Motion Cueing Algorithms (MCA) for self-motion generation in VR simulators. The proposed analysis and improvements are performed on a 3-DOF heave-pitch-roll manipulator with rotational motors, commonly used for low-cost motion-based commercial simulators. The analysis has been empirically validated against a real 3-DOF …
Experimental study and numerical simulation of inclined rectangular weirs
2018
Inclined rectangular weirs, also named pivot weirs, are used both to adjust the upstream water level and to increase the flow capacity compared with that of normal rectangular weirs. However, the experimental studies available in the literature present contradictory conclusions for the inclined weir discharge capacity. In this paper, new experimental runs and numerical simulations were performed to investigate the effect of the rectangular weir inclination angle on the stage-discharge formula. The experiments were carried out using inclination angles ranging from 30° to 90°. Buckingham's theorem of dimensional analysis was used to obtain an equation for the flow magnification ratio (the dis…
Flow measurement using circular portable flume
2018
Abstract The circular portable flume is a simple device to measure discharge in circular drainage networks. Since the unit can be easily installed and removed, it is helpful in water distribution measurement and management. First in this paper the available studies are reviewed for highlighting the effect of both the contraction ratio and the flume slope on the stage-discharge relationship. Then the Buckingham's Theorem of the dimensional analysis and the self-similarity theory are used to deduce the stage-discharge curve of the circular flume. The new theoretical stage-discharge equation is calibrated by the literature available experimental data and those obtained in this experimental inv…
A new strategy to maximize organic matter valorization in municipalities: combination of urban wastewater with kitchen food waste and its treatment w…
2017
[EN] The aim of this study was to evaluate the feasibility of treating the kitchen food waste (FW) jointly with urban wastewater (WW) in a wastewater treatment plant (WWTP) by anaerobic membrane technology (AnMBR). The experience was carried out in six different periods in an AnMBR pilot-plant for a total of 536 days, varying the SRT, HRT and the food waste penetration factor (PF) of food waste disposers. The results showed increased methane production of up to 190% at 70 days SRT, 24 hours HRT and 80% PF, compared with WW treatment only. FW COD and biodegradability were higher than in WW, so that the incorporation of FW into the treatment increases the organic load and the methane producti…
A comprehensive comparison between halophilic granular and flocculent sludge in withstanding short and long-term salinity fluctuations
2018
The effects of salinity fluctuations on the activity of autochthonous halophilic bacteria in aerobic granular sludge (AGS) and flocculent activated sludge (FAS) reactors were investigated. The response of nitrifiers and denitrifiers activity to drastic and moderate salinity shocks in the short-term (ST) and long-term (LT) was examined. The BOD5removal efficiency decreased only in the reactors subjected to the drastic LT salinity increase. Nevertheless, stable performances were achieved 18 days after the shock in the AGS-R1 (90%), whereas after 27 days in the FAS-R1 (82%). The loss in nitritation efficiency was higher in the FAS reactors and was proportional to the shock intensity. Nitritati…
Discussion of "extraction of the flow rate equation under free and submerged flow conditions in pivot weirs with different side contractions" by N. S…
2018
This paper is the discusison of the paper "Extraction of the flow rate equation under free and submerged flow conditions in pivot weirs with different side contractions" by N. Sheikh Rezazadeh Nikou, M. J. Monem, and K. Safavi.
Soil genetic erosion: New conceptual developments in soil security
2019
In the last decades, in some Mediterranean areas, pedodiversity decreased mainly due to pedotechnique application in large-scale farming that transformed original soils into Anthrosols. Supporting the consideration that soils can be considered as living systems, the original concept of 'soil genetic erosion' is re-proposed. Data, extrapolated and modeled from a Soil Information System in a study case representative of a Mediterranean landscape, predicted that most of the soil types would disappear in few years leading to a decrease of the soil diversity and originating soil genetic erosion. This circumstance is intentionally here told in form of a story where the fairy tale characters are s…
Testing soil water repellency in a Sicilian area two years after a fire
2019
The water drop penetration time (WDPT) technique was applied in 2018 to check persistence of soil water repellency (SWR) in a Sicilian mountain area affected by a wildfire on June 2016. A total of four sites, that were severely water repellent immediately after burning, were sampled. Depending on the site, wettable soil conditions, less SWR and maintenance of a noticeable SWR were detected two years later. At the site showing a near-constant SWR, WDPTs were particularly high in the top soil layer (0-0.03 m) and they appreciably decreased more in depth. Signs of decreasing SWR in drier soil conditions and in association with coarser soil particles were also detected at this site. High gradie…
Waste activated sludge dewaterability: comparative evaluation of sludge derived from CAS and MBR systems
2016
Nowadays, sludge dewatering is one of the greatest operational cost to wastewater treatment cycle. Specifically, 1t of fresh sludge to be disposed is composed, on average, by 0.25 - 0.30t of suspended solids, with an average cost for treatment and disposal around 280 - 470 €/t of suspended solids. Despite several technologies have been developed with the focus to reduce also the specific sludge production, still mechanical dewatering represents a crucial step to limit the amount of sludge to be disposed. Many physical–chemical parameters influence the sludge dewaterability: floc structure, particle size, bound water content, surface charge and hydrophobicity, Extracellular Polymeric Substan…