238 research outputs found
First- and second-generation valorisation of wastes and residues occurring in the food supply chain
Despite the high potential to increase sustainability of food systems, wastes and by-products occurring in the food supply chain are currently only partially valorised at different value-added levels. First-generation valorisation strategies that aim at utilisation of complete material streams for production of animal feed, energy, compost and/or specific consumer applications are already widely implemented and experience further dissemination and/or development (e.g. biohydrogen/biohythane production) – either in the form of single processes or as part of cascade utilisations. Second-generation valorisation strategies comprise various forms of fractionised utilisation of material streams. They rely on integration of adapted recovery and conversion procedures for specific components in order to obtain sequentially different classes of products, e.g. fine chemicals, commodity products and biofuels. Such advanced strategies are particularly suitable for wastes and by-products occurring during industrial food processing. Valorisation of food by-products for functional food is an emerging trend
A new genus and new species of Philippine stick insects (Insecta: Phasmatodea) and phylogenetic considerations
Occurrence of the genus <i>Ophicrania</i> Kaup (Insecta: Phasmatodea) in Panay island (Philippines) and description of a new species
New hardware and software technologies for real-time control in nuclear fusion experiments
The current machines for the study of nuclear fusion does not produce energy, and their output is substantially a large amount of data.
The accuracy of the data collected, and their density within narrow temporal samples, can determine the effectiveness of the real time control systems to install in future reactors.
We set ourselves the objective to design and test a high-speed and high-density data acquisition system based on the latest generation FPGA technologies.
in the thesis is used the latest products released by Xilinx to design a acquire stream system of signals from generic probes (specifically magnetic probes).
The Zynq 7000 family is nowadays state of the art of sistemy SoC that integrating a powerful and extensive FPGA section with an ARM mullticore.
Of fundamental importance will be the drastic reduction of signal cables between the sensory apparatus and acquisition systems with the dual objective of eliminating the noise induced and drastically lower installation costs.
Magnetic field configuration in RFX is characterised by fast variations of all the three field components during the pulse, with relevant non axis-symmetry in toroidal direction. Typical spectra exhibit modes up to n=15 in toroidal direction and mainly m=0 and m=1 in poloidal direction.
As a consequence, probe signals have a large dynamic (more than 60 dB), and extended frequency spectrum (several tens of kHz).
Therefore, a large number of probes are required to correctly identify the complex spatial structure of the plasma column.
To reduce shielding effects, probes must be installed inside the stabilising shell.
The three components of field outside the vacuum vessel can be very different in amplitude.
At the same time, one can reach 0.8 T and another can be typically lower than some mT. Furthermore, they vary very quickly.
The probes to be installed have to guarantee an uncertainty less than 1 mT to correctly reconstruct the plasma behaviour.
These two specifications are particularly stringent and require an accurate calibration and a careful probe alignment to minimise the spurious effect of unwanted components.
A further design specification for the sensors is due to the maximum operation temperature of the vacuum vessel (200 °C).
The analogic acquires systems must exhibit high isolation, high speed and resolution, but above all a low noise level.
The noise must be below minimum margins throughout the frequency spectrum contained in the signals provided by magnetic probes.
The main topic of the thesis is to verify the suitability of the ATCA MIMO ISOL modules in the upper and lower part of the signal spectrum of bi-axis magnetic probes in order to be able to be integrated into the new FPGA acquisition and realtime control in RFX systems
Effect of the temperature in a mixed culture pilot scale aerobic process for food waste and sewage sludge conversion into polyhydroxyalkanoates
The utilisation of urban organic waste as feedstock for polyhydroxyalkanoates (PHA) production is growing since it allows to solve the main concerns about their disposal and simultaneously to recover added-value products. A pilot scale platform has been designed for this purpose. The VFA-rich fermentation liquid coming from the anaerobic treatment of both source-sorted organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS) has been used as substrate for the aerobic process steps: a first sequencing batch reactor (SBR, 100 L) for the selection of a PHA-producing biomass, and a second fed-batch reactor (70 L) for PHA accumulation inside the cells. The SBR was operated at 2.0-4.4 kg COD/(m3 d) as OLR, under dynamic feeding regime (feast-famine) and short hydraulic retention time (HRT; 1 day). The selected biomass was able to accumulate up to 48% g PHA/g VSS. Both steps were performed without temperature (T) control, avoiding additional consumption of energy. In this regard, the applied OLR was tuned based on environmental T and, as a consequence, on biomass kinetic, in order to have a constant selective pressure. The latter was mainly quantified by the PHA storage yield (YP/Sfeast 0.34-0.45 CODP/CODS), which has been recognized as the main parameters affecting the global PHA productivity [1.02-1.82 g PHA/(L d)] of the process
Feasibility of thermophilic anaerobic processes for treating waste activated sludge under low HRT and intermittent mixing
Thermophilic anaerobic digestion (AD) arises as an optimized solution for the waste activated sludge (WAS) management. However, there are few feasibility studies using low solids content typically found in the WAS, and that consider uncommon operational conditions such as intermittent mixing and low hydraulic retention time (HRT). In this investigation, a single-stage pilot reactor was used to treat WAS at low HRT (13, 9, 6 and 5 days) and intermittent mixing (withholding mixing 2 h prior feeding). Thermophilic anaerobic digestion (55 degrees C) was initiated from a mesophilic digester (35 degrees C) by the one-step startup strategy. Although instabilities on partial alkalinity (1245-3000 mgCaCO(3)/L), volatile fatty acids (1774-6421 mg/L acetic acid) and biogas production (0.21-0.09 m(3)/m(reactor)(3).d) were observed, methanogenesis started to recover in 18 days. The thermophilic treatment of WAS at 13 and 9 days HRT efficiently converted VS into biogas (22 and 21%, respectively) and achieved high biogas yield (0.24 and 0.22 m(3)/kgVS(fed), respectively). Intermittent mixing improved the retention of methanogens inside the reactor and reduced the washout effect even at low HRT (<9 days). The negative thermal balance found was influenced by the low solids content in the WAS (2.1% TS) and by the heat losses from the digester walls. The energy balance and economic analyses demonstrated the feasibility of thermophilic AD of WAS in a hypothetical full-scale system, when the heat energy could be recovered from methane in a scenario of higher solids concentration in the substrate (>5% TS). (C) 2017 Elsevier Ltd. All rights reserved
Optical gain in DNA-DCM for lasing in photonic materials
We present a detailed study of the gain length in an active medium obtained
by doping of DNA strands with DCM dye molecules. The superior thermal stability
of the composite and its low quenching, permits to obtain optical gain
coefficient larger than 300 cm^-1. We also show that such an active material is
excellent for integration into photonic nano-structures, to achieve, for
example, efficient random lasing emission, and fluorescent photonic crystals
Cross-regulation between Aurora B and Citron kinase controls midbody architecture in cytokinesis.
Cytokinesis culminates in the final separation, or abscission, of the two daughter cells at the end of cell division. Abscission relies on an organelle, the midbody, which forms at the intercellular bridge and is composed of various proteins arranged in a precise stereotypic pattern. The molecular mechanisms controlling midbody organization and function, however, are obscure. Here we show that proper midbody architecture requires cross-regulation between two cell division kinases, Citron kinase (CIT-K) and Aurora B, the kinase component of the chromosomal passenger complex (CPC). CIT-K interacts directly with three CPC components and is required for proper midbody architecture and the orderly arrangement of midbody proteins, including the CPC. In addition, we show that CIT-K promotes Aurora B activity through phosphorylation of the INCENP CPC subunit at the TSS motif. In turn, Aurora B controls CIT-K localization and association with its central spindle partners through phosphorylation of CIT-K's coiled coil domain. Our results identify, for the first time, a cross-regulatory mechanism between two kinases during cytokinesis, which is crucial for establishing the stereotyped organization of midbody proteins.C.M. holds a Cambridge Cancer Centre PhD studentship, which is supported by Cancer Research UK and the MRC. Z.I.B. was supported by a Gwynaeth Pretty PhD studentship and the BlueGnome Molecular Genetics Fund from the Department of Pathology, University of Cambridge, and was also a recipient of a short-term EMBO fellowship and a fellowship from the Cambridge Philosophical Society. G.C. and M.G. are supported by a grant ‘Progetto di Ricerca di Interesse Nazionale’ (PRIN 2012) from the Ministero dell'Istruzione, Università e Ricerca. P.P.D. is the recipient of the Maplethorpe Fellowship from Murray Edwards College, Cambridge, UK.This is the final version of the article. It first appeared from Royal Society Publishing via https://doi.org/10.1098/rsob.16001
Exploiting Tannery Sludge as Renewable Resource for Biogas and Short-chain Fatty (SCFAs) Acids Production
The tannery industry is a very lucrative and widespread sector in Italy, and it is yet one of the most polluting, mainly due to the tannery sludge’s disposal in landfills, as it is considered a special residue by Italian legislation. An evaluation of the performance of the anaerobic fermentation process to obtain biogas and short-chain fatty acids (SCFAs) has been performed in this paper in different conditions concerning temperature, total solids content, and oxidizing and/or thermal pretreatments. The batch test trials revealed that the hydrogen peroxide pretreatment proved to be effective in increasing the biogas production, already at low doses but reaching the highest amount of 204 mL with the dose of 0.6 g H2O2/gTS. Regarding the SCFAs production, the combined microwave and hydrogen peroxide (MW-H2O2) pretreatment followed by thermophilic conditions gave the best results, with maximal SCFA concentration above 24 g CODSCFA/L.
In the tests conducted without pretreatment, the mesophilic temperature seem preferable since the acidification performances were comparable to or even better than their thermophilic counterparts while being less energy intensive. The obtained results proved that tannery sludge can be employed in different ways and provide a viable alternative to landfilling, to handle this waste in a greener way, in a circular economy approach
Rab1 interacts with GOLPH3 and controls Golgi structure and contractile ring constriction during cytokinesis in Drosophila melanogaster
Cytokinesis requires a tight coordination between actomyosin ring constriction and new membrane addition along the ingressing cleavage furrow. However, the molecular mechanisms underlying vesicle trafficking to the equatorial site and how this process is coupled with the dynamics of the contractile apparatus are poorly defined. Here we provide evidence for the requirement of Rab1 during cleavage furrow ingression in cytokinesis. We demonstrate that the gene omelette (omt) encodes the Drosophila orthologue of human Rab1 and is required for successful cytokinesis in both mitotic and meiotic dividing cells of Drosophila melanogaster. We show that Rab1 protein colocalizes with the conserved oligomeric Golgi (COG) complex Cog7 subunit and the phosphatidylinositol 4-phosphate effector GOLPH3 at the Golgi stacks. Analysis by transmission electron microscopy and 3D-SIM super-resolution microscopy reveals loss of normal Golgi architecture in omt mutant spermatocytes indicating a role for Rab1 in Golgi formation. In dividing cells, Rab1 enables stabilization and contraction of actomyosin rings. We further demonstrate that GTP-bound Rab1 directly interacts with GOLPH3 and controls its localization at the Golgi and at the cleavage site. We propose that Rab1, by associating with GOLPH3, controls membrane trafficking and contractile ring constriction during cytokinesis
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