614 research outputs found
Dark Universe and distribution of Matter as Quantum Imprinting: the Quantum Origin of Universe
In this paper we analyze the Dark Matter problem and the distribution of
matter through two different approaches, which are linked by the possibility
that the solution of these astronomical puzzles should be sought in the quantum
imprinting of the Universe. The first approach is based on a cosmological model
formulated and developed in the last ten years by the first and third authors
of this paper; the so-called Archaic Universe. The second approach was
formulated by Rosen in 1933 by considering the Friedmann-Einstein equations as
a simple one-dimensional dynamical system reducing the cosmological equations
in terms of a Schroedinger equation. As an example, the quantum memory in
cosmological dynamics could explain the apparently periodic structures of the
Universe while Archaic Universe shows how the quantum phase concernts not only
an ancient era of the Universe, but quantum facets permeating the entire
Universe today.Comment: 18 page
Storming Majorana's Tower with OAM states of light in a plasma
We extend the relationship between mass and spin angular momentum, described
by the bosonic spectrum of positive definite mass particles of the Majorana
solution to the Dirac equation, to photons that acquire an effective Proca mass
through the Anderson-Higgs mechanism when they propagate in a plasma. In an
earlier paper we showed that if the plasma is structured, it can impart orbital
angular momentum (OAM) to the photons that reduces the total Proca photon mass.
Here we show, through a generalisation of Majorana's solution, that photons
with OAM in a plasma cannot assume negative squared mass states. This means
that there exist interesting analogies with Quantum Gravity or General
Relativity models involving a modified action of the Lorentz group.Comment: 4 pages; Corrected, updated versio
Quantum oscillations in the black hole horizon
By applying Rosen's quantization approach to the historical Oppenheimer and
Snyder gravitational collapse and by setting the constraints for the formation
of the Schwarzschild black hole (SBH), in a previous paper [1] two of the
Authors (CC and FF) found the gravitational potential, the Schrodinger
equation, the solution for the energy levels, the area quantum and the quantum
representation of the ground state at the Planck scale of the SBH. Such results
are consistent with previous ones in the literature. It was also shown that the
traditional classical singularity in the core of the SBH is replaced by a
quantum oscillator describing a non-singular two-particle system where the two
components, named the "nucleus" and the "electron", strongly interact with each
other through a quantum gravitational interaction. In agreement with the de
Broglie hypothesis, the "electron" is interpreted in terms of the quantum
oscillations of the BH horizon. In other words, the SBH should be the
gravitational analogous of the hydrogen atom. In this paper, it is shown that
these results allow us to compute the SBH entropy as a function of the BH
principal quantum number in terms of Bekenstein-Hawking entropy and three
sub-leading corrections. In addition, the coefficient of the formula of
Bekenstein-Hawking entropy is reduced to a quarter of the traditional value.
Then, it is shown that, by performing a correct rescaling of the energy levels,
the semi-classical Bohr-like approach to BH quantum physics, previously
developed by one of the Authors (CC), is consistent with the obtained results
for large values of the BH principal quantum number. After this, Hawking
radiation will be analysed by discussing its connection with the BH quantum
structure. Finally, it is shown that the time evolution of the above mentioned
system solves the BH information paradox.Comment: 29 pages.Comments are welcome. arXiv admin note: text overlap with
arXiv:1912.0647
Lignin degradation efficiency of chemical pre-treatments on banana rachis destined to bioethanol production
Valuable biomass conversion processes are highly dependent on the use of effective pretreatments for lignocellulose degradation and enzymes for saccharification. Among the nowadays available treatments, chemical delignification represents a promising alternative to physical-mechanical treatments. Banana is one of the most important fruit crops around the world. After harvesting, it generates large amounts of rachis, a lignocellulosic residue, that could be used for second generation ethanol production, via saccharification and fermentation. In the present study, eight chemical pretreatments for lignin degradation (organosolv based on organic solvents, sodium hypochlorite, hypochlorous acid, hydrogen peroxide, alkaline hydrogen peroxide, and some combinations thereof) have been tested on banana rachis and the effects evaluated in terms of lignin removal, material losses, and chemical composition of pretreated material. Pretreatment based on lignin oxidation have demonstrated to reach the highest delignification yield, also in terms of monosaccharides recovery. In fact, all the delignified samples were then saccharified with enzymes (cellulase and beta-glucosidase) and hydrolysis efficiency was evaluated in terms of final sugars recovery before fermentation. Analysis of Fourier transform infrared spectra (FTIR) has been carried out on treated samples, in order to better understand the structural effects of delignification on lignocellulose. Active chlorine oxidations, hypochlorous acid in particular, were the best effective for lignin removal obtaining in the meanwhile the most promising cellulose-to-glucose conversion
Improving efficiency and discharge power of acid-base flow battery via a bi-objective optimisation
The implementation of effective storage systems is essential for a deeper market penetration of intermittent renewable sources. One promising, environmentally friendly energy storage technology is the Acid-Base Flow Battery (AB-FB). In the charge phase it stores electricity in the form of pH and salinity gradients via Bipolar Membrane Electrodialysis, while in the discharge phase it applies the reverse process for the opposite conversion. Despite the clear benefits over other osmotic batteries, the potential of the AB-FB has been poorly explored. This study presents the first bi-objective optimisation of the AB-FB in terms of net round trip efficiency (RTEnet) and average net discharge power density per membrane area (NPDd). A comprehensive mathematical model previously developed by our research team was used to predict the battery performance. The ε-constraint approach was used to build curves of Pareto optimal solutions under various scenarios by letting several operating and design parameters to vary. Using current commercial membranes, optimal solutions yielded an RTEnet ranging from 32 % to 64 %, while the corresponding NPDd ranged from 19.5 W m− 2 to 4 W m− 2 . These results highlight the great potential of the AB-FB, as well as the need of a proper design of experimental stacks. Simulating hypothetical membranes with improved, yet realistic characteristics shifted the range of RTEnet and NPDd to 59.1–76.3 % and 23.2–4.4 W m− 2 , respectively, showing that the technological advancement in membrane manufacturing is essential for the development of high-performance AB-FB systems. Although the ABFB performs similarly to other batteries, it can be made of non-critical materials that are not subject to supply disruptions or economic dependency, making the AB-FB a sustainability-friendly option and a good candidate for the future energy storage systems scenario
Apparent Lorentz violation with superluminal Majorana neutrinos at OPERA?
From the data release of OPERA - CNGS experiment, and publicly announced on
23 September 2011, we cast a phenomenological model based on a Majorana
neutrino state carrying a fictitious imaginary mass term, already discussed by
Majorana in 1932. This mass term can be induced by the interaction with the
matter of the Earth's crust during the 735 Km travel. Within the experimental
errors, we prove that the model fits with OPERA, MINOS and supernova SN1987a
data. Possible violations to Lorentz invariance due to quantum gravity effects
have been considered.Comment: 4 pages, 1 figure, 1 table, updated with new data, new figure. Higgs
mass expected at (273.56 {\pm} 0.01) Ge
The molecular size continuum of soil organic phosphorus and its chemical associations
The chemical nature of most organic P (Porg) in soil remains ‘unresolved’ but is accounted for by a broad signal in the phosphomonoester region of solution 31P nuclear magnetic resonance (NMR) spectra. The molecular size range of this broad NMR signal and its molecular structure remain unclear. The aim of this study was to elucidate the chemical nature of Porg with increasing molecular size in soil extracts combining size exclusion chromatography (SEC) with solution 31P NMR spectroscopy. Gel-filtration SEC was carried out on NaOH-EDTA extracts of four soils (range 238-1135 mg Porg/kgsoil) to collect fractions with molecular sizes of 70 kDa. These were then analysed by NMR spectroscopy.
Organic P was detected across the entire molecular size continuum from 70 kDa. Concentrations of Porg in the >10kDa fraction ranged from 107 to 427 mg P/kgsoil and exhibited on average three to four broad signals in the phosphomonoester region of NMR spectra. These broad signals were most prominent in the 10-20 and 20-50 kDa fractions, accounting for on average 77 % and 74 % of total phosphomonoesters, respectively. Our study demonstrates that the broad signal is present in all investigated molecular size fractions and comprises on average three to four components of varying NMR peak line width (20 to 250 Hz).
The stereoisomers myo- and scyllo-inositol hexakisphosphates (IP6) were also present across multiple molecular size ranges but were predominant in the 5-10 kDa fraction. The proportion of IP associated with large molecular size fractions >10 kDa was on average 23 % (SD=39 %) of total IP across all soils. These findings suggest that stabilisation of IP in soil includes processes associated with the organic phase
Lignin biodegradation in pulp-and-paper mill wastewater by selected white rot fungi
An investigation has been carried out to explore the lignin-degrading ability of white rot fungi, as B. adusta and P. crysosporium, grown in different media containing (i) glucose and mineral salts; (ii) a dairy residue; (iii) a dairy residue and mineral salts. Both fungi were then used as inoculum to treat synthetic and industrial pulp-and-paper mill wastewater. On synthetic wastewater, up to 97% and 74% of lignin degradation by B. adusta and P. crysosporium, respectively, have been reached. On industrial wastewater, both fungal strains were able to accomplish 100% delignification in 8-10 days, independent from pH control, with a significant reduction of total organic carbon (TOC) of the solution. Results have confirmed the great biotechnological potential of both B. adusta and P. crysosporium for complete lignin removal in industrial wastewater, and can open the way to next industrial applications on large scale
New bioassays reveal susceptibility of stone-fruit rootstocks to capnodis tenebrionis larvae
Larvae of Capnodis tenebrionis (L.) (Coleoptera Buprestidae) feed and develop in roots of stone-fruit trees, thereby decreasing their efficiency, which can lead to plant death. The control of these larvae is critical, due to their localization in the root, and the management of this pest is focused on adults, mainly by using non-specific synthetic insecticides. Less susceptible Prunus rootstocks might be applied as a preventative management of larval infestation by this pest. The current research investigated the susceptibility to C. tenebrionis larvae of the most commonly used rootstocks by combining two bio-assays during two-year trials: development of larvae assayed on semi-artificial substrates containing rootstock bark flour; infestation by neonate larvae on rootstock twigs. The rearing assay on semi-artificial substrates made it possible to distinguish (1) a rootstock cluster (Montclar and GF677) in which larvae developed faster and heavier and produced larger adults, (2) a cluster (Adesoto, CAB6P, Colt and MaxMa60) in which larval growth was less efficient as well as adult size, and (3) a cluster (Garnem and Myrabolan 29C) with intermediate responses in larval development and adult size. The twig infestation assay by neonates showed the most infested (Colt) and least infested (Barrier, MaxMa60 and Marianna 26) rootstocks. When the results of both assays are combined, GF677 and Myrabolan 29C appear more susceptible, while Adesoto and MaxMa60 less susceptible to C. tenebrionis larvae, although Barrier and Marianna 26 require further investigation. The experimental model applied in the current trials can enable processing of a large number of tests on different rootstocks, thereby allowing the accumulation of a large quantity of data on the potential susceptibility of rootstocks. The possibility of rearing larvae on a substrate can allow comparison of additional compounds that could interact with larval growth
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