120 research outputs found
Charger-mediated energy transfer in exactly-solvable models for quantum batteries
We present a systematic analysis and classification of several models of
quantum batteries involving different combinations of two level systems and
quantum harmonic oscillators. In particular, we study energy transfer processes
from a given quantum system, termed charger, to another one, i.e. the proper
battery. In this setting, we analyze different figures of merit, including the
charging time, the maximum energy transfer, and the average charging power. The
role of coupling Hamiltonians which do not preserve the number of local
excitations in the charger-battery system is clarified by properly accounting
them in the global energy balance of the model.Comment: 11 page
Nutritional Quality of Meat Analogues: Results From the Food Labelling of Italian Products (FLIP) Project
Nowadays, the interest in meat substitutes is increasing, and consumers perceive their nutritional quality better than that of the animal products they intend to resemble. Therefore, this work aimed to investigate the overall nutritional quality of these new products. Regulated information [Regulation (EU) 1169/2011], the presence/absence of nutrition or health claim and organic declarations, the gluten-free indication, and the number of ingredients were collected from the food labels of 269 commercial meat analogues currently sold on the Italian market. Nutritional information of reference animal meat products was used to compare the nutrition profile. As an indicator of the nutritional quality, the Nutri-Score of meat analogues and counterparts was also determined. Plant-based steaks showed significantly higher protein, lower energy, fats and salt contents, and better Nutri-Scores than the other analogues. All the meat analogues showed a higher fibre content than meat products, while plant-based burgers and meatballs had lower protein contents than meat counterparts. Ready-sliced meat analogues showed a lower salt content than cured meats. Overall, all these plant-based products showed a longer list of ingredients than animal meat products. Results from this survey highlighted that plant-based steaks, cutlets, and cured meats have some favourable nutritional aspects compared to animal-based products. However, they cannot be considered a "tout-court" alternative to meat products from a nutritional point of view
Measurements with the ELI-NP cavity Beam Position Monitor Read-out Electronics at FLASH
The Extreme Light Infrastructure - Nuclear Physics
Gamma Beam System (ELI-NP GBS) will be installed and
commissioned starting within the next year in Magurele,
Romania. It will generate gamma beam through Compton
back-scattering of a recirculated laser and a multi-bunch
electron beam, produced by a 720 MeV LINAC. In order
to obtain bunch by bunch position measurements, four cavity
beam position monitors (cBPM) near the two interaction
points are foreseen. Extensive tests on the cBPM readout
electronics, recently developed by Instrumentation
Technologies and acquired for ELI-NP GBS, were performed
in laboratory at INFN-LNF and at FLASH in
DESY, during the user operation. In the latter case, three
cBPMs installed along the LINAC, with similar features as
the ones of ELI-NP GBS, were used as measuring devices
and signal sources for the read-out electronics under test.
We present here the measurements collected and the related
analysis, with a particular focus on the beam position
measurement resolution
Revisiting the "Fundamental Plane" of Black Hole Activity at Extremely Low Luminosities
We investigate the origin of the X-ray emission in low-luminosity AGNs
(LLAGNs). Yuan & Cui (2005) predicted that the X-ray emission should originate
from jets rather than from an advection-dominated accretion flow (ADAF) when
the X-ray luminosity of the source is below a critical value of
. This prediction implies that the
X-ray spectrum in such sources should be fitted by jets rather than ADAFs.
Furthermore, below the correlation between radio ()
and X-ray () luminosities and the black hole mass ()--the
so-called fundamental plane of black hole activity--should deviate from the
general correlation obtained by Merloni, Heinz & Di Matteo (2003) and become
steeper. The Merloni et al. correlation is described by , while the predicted correlation is
. We collect
data from the literature to check the validity of these two expectations. We
find that among the 16 LLAGNs with good X-ray and radio spectra, 13 are
consistent with the Yuan & Cui prediction. For the 22 LLAGNs with , the fundamental plane correlation is described by , also in excellent
agreement with the prediction.Comment: 24 pages, 2 tables, 3 figures; accepted by Ap
The nuclear X-ray emission of nearby early-type galaxies
Nuclear hard X-ray luminosities (Lx,nuc) for a sample of 112 early type
galaxies within a distance of 67 Mpc are used to investigate their relationship
with the central galactic black hole mass Mbh, the inner galactic structure
(using the parameters describing its cuspiness), the age of the stellar
population in the central galactic region, the hot gas content and the core
radio luminosity. Lx,nuc ranges from 10^{38} to 10^{42} erg/s, and the
Eddington ratio Lx,nuc/Ledd from 10^{-9} to 10^{-4}. Lx,nuc increases on
average with the galactic luminosity Lb and Mbh, with a wide variation by up to
4 orders of magnitude at any fixed Lb>6x10^9 Lb,sun or Mbh>10^7 Msun. This
large range should reflect a large variation of the mass accretion rate
\dotMbh. On the circumnuclear scale, \dotMbh at fixed Lb (or Mbh) could vary
due to differences in the fuel production rate from the stellar mass return
linked to the inner galactic structure; however, \dotMbh should vary with
cuspiness by a factor exceeding a few only in hot gas poor galaxies and for
large differences in the core radius. Lx,nuc does not depend on age, but less
luminous nuclei are found among galaxies with a younger stellar component.
Lx,nuc is detected both in gas poor and gas rich galaxies, on average increases
with the total galactic hot gas cooling rate L_{X,ISM}, but again with a large
variation. The lack of a tight relationship between Lx,nuc and the
circumnuclear and total gas content can be explained if the gas is heated by
black hole feedback, and/or the mass effectively accreted can be largely
reduced with respect to that entering the circumnuclear region. Differently
from Lx,nuc, the 5 GHz VLA luminosity shows a trend with the inner galactic
structure similar to that of the total soft X-ray emission; therefore they
could both be produced by the hot gas.Comment: To appear in the ApJ, 21 page
Nutritional Quality of Wholegrain Cereal-Based Products Sold on the Italian Market: Data from the FLIP Study
The consumption of wholegrains (WG) is encouraged worldwide, but the lack of a common legal definition of such products leads to an unclear classification and identification on the grocery store shelf. In Italy, several products are generally sold as WG, but it cannot be determined if they are made entirely with all WG cereal(s) or if they are partially produced with WG ingredients (PWG). The aims of this study were to (a) survey the number of cereal-based food items formulated with WG, PWG, or refined (RG) present on the Italian market; and (b) analyse the nutritional quality, intended as nutrition facts, of WG products in comparison to PWG and RG. Nutritional information and declarations were retrieved from packs of 3040 products belonging to five different categories: breakfast cereals, biscuits, sweet snacks, bread, and bread substitutes. A descriptive analysis of the products and comparison of energy, macronutrients, fibre and salt among RG, PWG and WG products within each category was performed. In all categories, a major portion of the products did not contain WG ingredients. Results showed that the nutritional quality of RG, PWG, and WG products varied in relation to the product category and that WG inclusion cannot be always considered a marker of the overall nutritional quality of foods. Instead, it is necessary to evaluate the global product characteristics, and it is important to pay attention to differences between WG and PWG products that can be perceived by consumers as equivalent
Nutritional Quality of Pasta Sold on the Italian Market: The Food Labelling of Italian Products (FLIP) Study
Breakfast Cereals Carrying Fibre-Related Claims: Do They Have a Better Nutritional Composition Than Those without Such Claims? Results from the Food Labelling of Italian Products (FLIP) Study
Nutrition claims (NCs) on food packaging are, from one side, an informative tool about the nutritional characteristics of the product. From another side, they could bias the consumer in perceiving such products as healthier than those without claims. In order to investigate whether products with NCs have a better nutritional composition that those without claims, the present study aimed to compare the nutrition facts of 376 breakfast cereals, with and without fibre-related NCs, available in 13 Italian retailer online stores. Among these products, 73 items claimed to be a “source of fibre” and 109 “high in fibre”. In addition to a higher fibre content, products “high in fibre” showed higher protein and fat contents but lower carbohydrate, sugar and salt contents compared to both “source of fibre” and without fibre-related NC items. Overall, a high variability in nutritional values was also observed within products with the same type of fibre-related NC. In conclusion, the results suggested that fibre-related NCs should not be considered as a marker of a better nutritional composition of breakfast cereals, and thus consumers should be educated to carefully read the entire nutritional information reported in the food labelling
Sodium Content in Cereal-Based Products Sold in Italy: How Far Are We from the Global Benchmarks?
Reformulation of food products is one of the measures needed for reducing salt consumption. Accordingly, the World Health Organization (WHO) recently proposed global sodium benchmarks for different food categories to be used for setting national policies. Therefore, the sodium content of cereal-based products currently sold in Italy was compared with the WHO benchmarks, highlighting those categories primarily needing a reformulation. To this aim, the sodium content and several declarations (i.e., nutrition and health claims, organic or gluten free declaration) were retrieved from 2917 cereal-based products sold on the Italian market. All “minimally processed breakfast cereals” had a sodium content below the benchmark, while “flatbreads” and “leavened bread” had the highest percentage of items above the respective sodium benchmarks. Flatbreads and “crackers/savory biscuits” showed the highest median delta values from the respective benchmarks of 360 and 278 mg/100 g, respectively. Large variability in terms of percentage of products with sodium content above the benchmark was observed within the same categories, as well as among products with different declarations. A large number of food products currently sold on the Italian market have a sodium content above the benchmark. This result suggests the need to reformulate many food products currently on the market to achieve the WHO/United Nations (UN) objective of 30% global reduction in sodium intake by 2025
Evidence for Rapidly Rotating Black Holes in FR I Radio Galaxies
We investigate the correlation between 151 MHz radio luminosity, L_151MHz,
and jet power, P_jet, for a sample of low-power radio galaxies, of which the
jet power is estimated from X-ray cavities. The jet power for a sample of FR I
radio galaxies is estimated with the derived empirical correlation. We find
that P_jet/L_Edd is positively correlated with Lx(2-10 keV)/L_Edd for FR Is,
where L_Edd is the Eddington luminosity and Lx(2-10 keV) is 2-10 keV X-ray
luminosity. We calculate the jet power of a hybrid model, as a variant of
Blandford-Znajek model proposed by Meier, based on the global solution of the
advection-dominated accretion flow (ADAF) surrounding a Kerr black hole (BH).
Our model calculations suggest that the maximal jet power is a function of mass
accretion rate and the black hole spin parameter j. The hard X-ray emission is
believed to be mainly from the ADAFs in FR Is, and the mass accretion rate is
therefore constrained with the X-ray emission in our ADAF model calculations.
We find that the dimensionless angular momentum of BH j>~0.9 is required in
order to reproduce the observed relation of P_jet/L_Edd-Lx(2-10 keV)/L_Edd for
FR Is. Our conclusion will be strengthened if part of the X-ray emission is
contributed by the jets. Our results suggest that BHs in FR I radio galaxies
are rapidly spinning, which are almost not affected by the uncertainty of the
black hole mass estimates.Comment: Accepted by Ap
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