556 research outputs found
Frequency of Trade and the Determinancy of Equilibrium Paths: Logarithmic Economies of Overlapping Generations Under Certainty
General features of the energy landscape in Lennard-Jones like model liquids
Features of the energy landscape sampled by supercooled liquids are
numerically analyzed for several Lennard-Jones like model systems. The
properties of quasisaddles (minima of the square gradient of potential energy
W=|grad V|^2), are shown to have a direct relationship with the dynamical
behavior, confirming that the quasisaddle order extrapolates to zero at the
mode-coupling temperature T_MCT. The same result is obtained either analyzing
all the minima of W or the saddles (absolute minima of W), supporting the
conjectured similarity between quasisaddles and saddles, as far as the
temperature dependence of the properties influencing the slow dynamics is
concerned. We find evidence of universality in the shape of the landscape:
plots for different systems superimpose into master curves, once energies and
temperatures are scaled by T_MCT. This allows to establish a quantitative
relationship between T_MCT and potential energy barriers for LJ-like systems,
and suggests a possible generalization to different model liquids.Comment: 8 pages, 5 figure
Technical, economic and environmental assessement of bioethanol biorefinery from waste biomass
This study presents a sequential three-steps methodology for the technical, economic and environmental assessment (TEEA) of bioethanol production from waste biomass. In EU the most abundant waste biomasses produced in 2018 could be ascribed to three main categories: lignocellulosic (329.41 Mt), starch (160 Mt) and sugar-based (58.56 Mt). The technical assessment compiled an inventory of the waste biomasses and subsequently designed their biological conversion into ethanol through integrated biorefinery processes by means of material flow analysis (MFA); the economic assessment was aimed at the definition of the cut-off size of the biorefinery plant necessary to achieve profitability; the environmental assessment was based on Life Cycle Analysis (LCA) and energy balance (i.e. energy input consumption). For each of the three waste biomass categories, at least one that was significant as available amount and representative in terms of physico-chemical characteristics, was evaluated: sugarcane for sugar-based, potatoes for starch-based and rice straw, cattle manure and organic fraction of municipal solid waste (OFMSW) for lignocellulosic biomasses. The technical assessment of the biorefinery routes lead to the following yields (kg of bioethanol per kg of biomass): 0.16, 0.17, 0.22, 0.19 and 0.14 respectively. The economic profitability was reached by all biorefineries and Net Present Value (MâŹ) were: 0.85 for sugarcane, 0.11 for potatoes, 0.09 for rice straw, 0.11 for cattle manure and 0.39 for OFMSW. From the environmental perspective, cattle manure reached the highest reduction of climate change and acidification impacts compared to other biomasses, while sugarcane achieved the lowest energy input consumption (around 64%)
Biowaste management in Italy: Challenges and perspectives
The aim of this work is the development of a methodology for the technical and
environmental assessment of biowaste valorization in 2G biorefineries. Italy was chosen as case study,
considering years 2016â2017. Approach: the Italian context was evaluated through the following
key parameters: Gross domestic power, climate, demography, and population density distribution
described the Italian framework. The four most abundant biowaste categories were defined through
their amounts and geo-localization: wastewater and sewage sludge (WSS, 4.06 Mt/y), organic fraction
of municipal solid waste (OFMSW, 1.7 Mt/y), agricultural livestock waste (ALW, 5.7 Mt/y), and waste
deriving from the food industry (FIW, 2.6 Mt/y). The geo-localization and quantitative evaluations
of the available biowaste amounts were aimed at defining the dimension and localization of the
biorefinery plant and at optimizing supply and transport chains, while the qualitative characteristic
were aimed to evaluate the most promising process among thermo-valorization (TH) and anaerobic
digestion (AD). Results: All considered biowastes were appropriate for biorefinery processes, since
carbon content exceeds 40% and the carbonânitrogen ratio was between 10 and 30. All biowaste
categories were evaluated as feedstocks for two biorefinery processes: anaerobic digestion (AD)
and thermo-valorization (TH) with energy recovery. Compared to TH, AD achieved in all cases the
best performances in terms of produced energy and avoided CO2 emissions. The primary energy
production of AD and TH for WSS, OFMSW, ALW, and FIW were respectively: 7.89 vs. 2.4 kWh/kg;
8.7 vs. 2.6 kWh/kg; 10.85 vs. 5.5 kWh/kg; and 12.5 vs. 7.8 kWh/kg. The main findings of this work
were: the adoption of AD was technically more suitable than TH; AD increased the avoided CO2
emissions of 10%â89.9% depending on biowaste category
Operationalizing perpetrator studies. Focusing readersâ reactions to The Kindly Ones by Jonathan Littell
Within the field of Holocaust Studies the last decade has witnessed a turn to the figure of the perpetrator, who had hitherto received little attention due to ethical, legal and psychological reasons. A similar turn can also be observed in connection with the study of empathy. In this context, the concept of ânegative empathy,â intended as a sharing of emotions with morally negative fictional characters, has become an increasingly discussed topic. For research in this area, the novel The Kindly Ones (2006) by Jonathan Littell takes up a privileged position in light of its intrinsic literary quality and due to its commercial and critical success. This novel recounts the memories of an SS-officer, Maximilian Aue, who participated in the Shoah. We have carried out an experiment using some passages of this novel to test the empathic reactions of (104) readers. Passages were presented under either of two conditions: as a fictional text or as part of an autobiography. Results showed that fictionalization has a significant effect on moral disengagement; readers who read the narrative presented to them as fictional experienced higher levels of moral disengagement compared to readers in the autobiography condition. Moreover, higher levels of moral disengagement led to significantly higher levels of empathy for the protagonist of the novel
Integrated biorefinery strategy for poly(3-hydroxybutyrate) accumulation in Cupriavidus necator DSM 545 using a sugar rich syrup from cereal waste and acetate from gas fermentation
Poly(3-hydroxybutyrate) (PHB) is one of the most well-known biodegradable and biocompatible biopolymers
produced by prokaryotic microorganisms. It belongs to the family of polyhydroxyalkanoates (PHAs), and it has
gained significant attention in recent years due to its potential as a sustainable alternative to traditional
petroleum-based plastics. Cupriavidus necator has been identified as a potential producer of PHB for industrial
applications due to its ability to produce high amounts of the polymer under controlled conditions, using a wide
range of waste substrates. In this study, the ability of Cupriavidus necator DSM 545 strain to produce PHB was
tested in a fed-batch strategy providing two different organic substrates. The first is a sugar-based syrup (SBS),
derived from cereal waste. The second is an acetate-rich medium obtained through CO2 -H2 fermentation by the
acetogenic bacterium Acetobacterium woodii. The carbon sources were tested to improve the accumulation of PHB
in the strain. C. necator DSM 545 proved to be able to grow and to perform high accumulation of biopolymer on
waste substrates containing glucose, fructose, and acetate, reaching about 10 g/L of PHB, 83% of biopolymer
accumulation in cell dry mass, in 48 h of fed-batch fermentation in 0.6 L working volume in a bioreactor.
Moreover, a Life Cycle Assessment analysis was performed to evaluate the environmental impact of the process
converting the sugar syrup alone and the integrated one. It demonstrated that the integrated process is more
sustainable and that the most impactful step is the PHB production, followed by the polymer extraction
The modification of the energy spectrum of charged particles by exotic open 4-smoothness via superstring theory
In this paper we present a model where the modified Landau-like levels of
charged particles in a magnetic field are determined due to the modified
smoothness of as underlying structure of the Minkowski
spacetime. Then the standard smoothness of is shifted to the
exotic , , . This is achieved by
superstring theory using gravitational backreaction induced from a strong,
almost constant magnetic field on standard . The exact string
background containing flat is replaced consistently by the
curved geometry of as part of the modified exact
backgrounds. This corresponds to the change of smoothness on
from the standard to some exotic . The
calculations of the spectra are using the CFT marginal deformations and
Wess-Zumino-Witten (WZW) models. The marginal deformations capture the effects
of the magnetic field as well as its gravitational backreactions. The spectra
depend on even level of WZW on SU(2). At the same time the WZ term as
element of determines also the exotic smooth
. As the consequence we obtain a non-zero mass-gap emerges
in the spectrum induced from the presence of an exotic .Comment: 11 pages, Revtex4-1, will appear IJGMMP Vol. 50(1), 201
A model for the generic alpha relaxation of viscous liquids
Dielectric measurements on molecular liquids just above the glass transition
indicate that alpha relaxation is characterized by a generic high-frequency
loss varying as , whereas deviations from this come from one or
more low-lying beta processes [Olsen et al, Phys. Rev. Lett. {\bf 86} (2001)
1271]. Assuming that long-wavelength fluctuations dominate the dynamics, a
model for the dielectric alpha relaxation based on the simplest coupling
between the density and dipole density fields is proposed here. The model,
which is solved in second order perturbation theory in the Gaussian
approximation, reproduces the generic features of alpha relaxation
Evaluation of [C(sp3)/[C(sp2)] ratio in diamondlike films through the use of a complex dielectric constant
The evaluation of the amount of tetrahedral and trigonal cross-linking, that is, the sp3- and sp2-hybridized carbon, is of great importance in understanding the properties of amorphous carbon films. In this paper we report a method for deducing the [sp3]/[sp2] ratio from the experimental values of the complex dielectric constant as obtained by optical transmittance and reflectance measurements. We assume a Gaussian-like distribution of Ï and Ï* electronic densities of states in order to fit the contribution of ÏâÏ* to the imaginary part, Δ2, of the dielectric constant in the low-energy region. Through the Kramers-Kronig relationships we deduce the corresponding values of the real part Δ1 of the dielectric constant for such transitions. By subtracting these values from the measured Δ1 we deduce the contribution of ÏâÏ* to Δ1. The Wemple-Didomenico model has been used to obtain the dispersion energy and the average excitation energy. Knowing the plasmon energies, we apply the ââf-sum rule'' to deduce the [sp3]/[sp2] ratio. The method applied to a-C:H films deposited by rf diode sputtering provides results in agreement with those obtained by other techniques
study on the afm force spectroscopy method for elastic modulus measurement of living cells
The cell elasticity gives information about its pathological state and metastatic potential. The aim of this paper is to study the AFM Force Spectroscopy technique with the future goal of realizing a reference method for accurate elastic modulus measurement in the elasticity range of living cells. This biological range has not been yet explored with a metrological approach. Practical hints are given for the realization of a Sylgard elasticity scale. Systematic effects given by the sample curing thickness and nanoindenter geometry have been found with regards of the measured elastic modulus. AFM measurement reproducibility better than 20% is obtained in the entire investigated elastic modulus scale of 101 â 104 kPa
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