279 research outputs found
Degrees of Freedom of the Quark Gluon Plasma, tested by Heavy Mesons
Heavy quarks (charm and bottoms) are one of the few probes which are
sensitive to the degrees of freedom of a Quark Gluon Plasma (QGP), which cannot
be revealed by lattice gauge calculations in equilibrium. Due to the rapid
expansion of the QGP energetic heavy quarks do not come to an equilibrium with
the QGP. Their energy loss during the propagation through the QGP medium
depends strongly on the modelling of the interaction of the heavy quarks with
the QGP quarks and gluons, i.e. on the assuption of the degrees of freedom of
the plasma. Here we compare the results of different models, the pQCD based
Monte-Carlo (MC@sHQ), the Dynamical Quasi Particle Model (DQPM) and the
effective mass approach, for the drag force in a thermalized QGP and discuss
the sensitivity of heavy quark energy loss on the properties of the QGP as well
as on non-equilibrium dynamicsComment: proceedings symposion "New Horizons" Makutsi, South Africa, Nov 201
Net Charge on a Noble Gas Atom Adsorbed on a Metallic Surface
Adsorbed noble gas atoms donate (on the average) a fraction of an electronic
charge to the substrate metal. The effect has been experimentally observed as
an adsorptive change in the electronic work function. The connection between
the effective net atomic charge and the binding energy of the atom to the metal
is theoretically explored.Comment: ReVvTeX 3.1 format, Two Figures, Three Table
Systematic model behavior of adsorption on flat surfaces
A low density film on a flat surface is described by an expansion involving
the first four virial coefficients. The first coefficient (alone) yields the
Henry's law regime, while the next three correct for the effects of
interactions. The results permit exploration of the idea of universal
adsorption behavior, which is compared with experimental data for a number of
systems
Finite difference calculations of permeability in large domains in a wide porosity range.
Determining effective hydraulic, thermal, mechanical and electrical properties of porous materials by means of classical physical experiments is often time-consuming and expensive. Thus, accurate numerical calculations of material properties are of increasing interest in geophysical, manufacturing, bio-mechanical and environmental applications, among other fields. Characteristic material properties (e.g. intrinsic permeability, thermal conductivity and elastic moduli) depend on morphological details on the porescale such as shape and size of pores and pore throats or cracks. To obtain reliable predictions of these properties it is necessary to perform numerical analyses of sufficiently large unit cells. Such representative volume elements require optimized numerical simulation techniques. Current state-of-the-art simulation tools to calculate effective permeabilities of porous materials are based on various methods, e.g. lattice Boltzmann, finite volumes or explicit jump Stokes methods. All approaches still have limitations in the maximum size of the simulation domain. In response to these deficits of the well-established methods we propose an efficient and reliable numerical method which allows to calculate intrinsic permeabilities directly from voxel-based data obtained from 3D imaging techniques like X-ray microtomography. We present a modelling framework based on a parallel finite differences solver, allowing the calculation of large domains with relative low computing requirements (i.e. desktop computers). The presented method is validated in a diverse selection of materials, obtaining accurate results for a large range of porosities, wider than the ranges previously reported. Ongoing work includes the estimation of other effective properties of porous media
Kinetin and nitrogen in agronomic characteristics of soybean.
The objective of this work was to evaluate the application of kinetin associated with nitrogen in coverage on the agronomic characteristics and soybean yield. In the 2016/2017 harvest, a 6x2 factorial scheme was used, six doses of kinetin (0; 0.30; 0.60; 0.90; 1.20; 1.50 g ha−1) and two doses of N (20 and 40 kg ha−1) and in the 2017/2018 harvest, factorial scheme 5x2 was used, five doses of kinetin (0; 0.25; 0.75; 1.00; 1.25 g ha−1) and two doses of N (20 and 40 kg ha−1). Agronomic plant height characteristics, first pod insertion height, number of grains per plant, number of pods per plant, number of grains per pod, number of grains per pod, hundred-grain mass and grain yield were evaluated. The use of N alone and associated with kinetin increased the number of pods and grains in the 2016/2017 harvest. In the 2017/2018 crop, kinetin caused a reduction of 8.9% at plant height and N caused an increase in plant height and first pod insertion and reduced the number of pods and grains per plant, grains per pods and productivity
Characterization of the degree of food processing in the European Prospective Investigation into Cancer and Nutrition: Application of the Nova classification and validation using selected biomarkers of food processing
Background: Epidemiological studies have demonstrated an association
between the degree of food processing in our diet and the risk of various
chronic diseases. Much of this evidence is based on the international Nova
classification system, which classifies food into four groups based on the type
of processing: (1) Unprocessed and minimally processed foods, (2) Processed
culinary ingredients, (3) Processed foods, and (4) “Ultra-processed” foods
(UPF). The ability of the Nova classification to accurately characterise the
degree of food processing across consumption patterns in various European
populations has not been investigated so far. Therefore, we applied the Nova
coding to data from the European Prospective Investigation into Cancer and
Nutrition (EPIC) in order to characterize the degree of food processing in our
diet across European populations with diverse cultural and socio-economic
backgrounds and to validate this Nova classification through comparison with
objective biomarker measurements.
Methods: After grouping foods in the EPIC dataset according to the Nova
classification, a total of 476,768 participants in the EPIC cohort (71.5% women;
mean age 51 [standard deviation (SD) 9.93]; median age 52 [percentile (p)25–
p75: 58–66] years) were included in the cross-sectional analysis that
characterised consumption patterns based on the Nova classification. The
consumption of food products classified as different Nova categories were
compared to relevant circulating biomarkers denoting food processing,
measured in various subsamples (N between 417 and 9,460) within the EPIC
cohort via (partial) correlation analyses (unadjusted and adjusted by sex,
age, BMI and country). These biomarkers included an industrial transfatty
acid (ITFA) isomer (elaidic acid; exogenous fatty acid generated during
oil hydrogenation and heating) and urinary 4-methyl syringol sulfate (an
indicator for the consumption of smoked food and a component of liquid
smoke used in UPF).
Results: Contributions of UPF intake to the overall diet in % grams/day varied
across countries from 7% (France) to 23% (Norway) and their contributions to
overall % energy intake from 16% (Spain and Italy) to >45% (in the UK and
Norway). Differences were also found between sociodemographic groups;
participants in the highest fourth of UPF consumption tended to be younger,
taller, less educated, current smokers, more physically active, have a higher
reported intake of energy and lower reported intake of alcohol. The UPF
pattern as defined based on the Nova classification (group 4;% kcal/day) was
positively associated with blood levels of industrial elaidic acid (r = 0.54) and
4-methyl syringol sulfate (r = 0.43). Associations for the other 3 Nova groups
with these food processing biomarkers were either inverse or non-significant
(e.g., for unprocessed and minimally processed foods these correlations were
–0.07 and –0.37 for elaidic acid and 4-methyl syringol sulfate, respectively).
Conclusion: These results, based on a large pan-European cohort,
demonstrate sociodemographic and geographical differences in the
consumption of UPF. Furthermore, these results suggest that the Nova
classification can accurately capture consumption of UPF, reflected by
stronger correlations with circulating levels of industrial elaidic acid and a
syringol metabolite compared to diets high in minimally processed foods
Characterization of the degree of food processing in the European Prospective Investigation into Cancer and Nutrition: Application of the Nova classification and validation using selected biomarkers of food processing
Background: Epidemiological studies have demonstrated an association between the degree of food processing in our diet and the risk of various chronic diseases. Much of this evidence is based on the international Nova classification system, which classifies food into four groups based on the type of processing: (1) Unprocessed and minimally processed foods, (2) Processed culinary ingredients, (3) Processed foods, and (4) Ultra-processed foods (UPF). The ability of the Nova classification to accurately characterise the degree of food processing across consumption patterns in various European populations has not been investigated so far. Therefore, we applied the Nova coding to data from the European Prospective Investigation into Cancer and Nutrition (EPIC) in order to characterize the degree of food processing in our diet across European populations with diverse cultural and socio-economic backgrounds and to validate this Nova classification through comparison with objective biomarker measurements. Methods: After grouping foods in the EPIC dataset according to the Nova classification, a total of 476,768 participants in the EPIC cohort (71.5% women; mean age 51 [standard deviation (SD) 9.93]; median age 52 [percentile (p)25-p75: 58-66] years) were included in the cross-sectional analysis that characterised consumption patterns based on the Nova classification. The consumption of food products classified as different Nova categories were compared to relevant circulating biomarkers denoting food processing, measured in various subsamples (N between 417 and 9,460) within the EPIC cohort via (partial) correlation analyses (unadjusted and adjusted by sex, age, BMI and country). These biomarkers included an industrial transfatty acid (ITFA) isomer (elaidic acid; exogenous fatty acid generated during oil hydrogenation and heating) and urinary 4-methyl syringol sulfate (an indicator for the consumption of smoked food and a component of liquid smoke used in UPF). Results: Contributions of UPF intake to the overall diet in % grams/day varied across countries from 7% (France) to 23% (Norway) and their contributions to overall % energy intake from 16% (Spain and Italy) to >45% (in the UK and Norway). Differences were also found between sociodemographic groups; participants in the highest fourth of UPF consumption tended to be younger, taller, less educated, current smokers, more physically active, have a higher reported intake of energy and lower reported intake of alcohol. The UPF pattern as defined based on the Nova classification (group 4;% kcal/day) was positively associated with blood levels of industrial elaidic acid (r = 0.54) and 4-methyl syringol sulfate (r = 0.43). Associations for the other 3 Nova groups with these food processing biomarkers were either inverse or non-significant (e.g., for unprocessed and minimally processed foods these correlations were -0.07 and -0.37 for elaidic acid and 4-methyl syringol sulfate, respectively). Conclusion: These results, based on a large pan-European cohort, demonstrate sociodemographic and geographical differences in the consumption of UPF. Furthermore, these results suggest that the Nova classification can accurately capture consumption of UPF, reflected by stronger correlations with circulating levels of industrial elaidic acid and a syringol metabolite compared to diets high in minimally processed foods
Optimal Energy Investment and R&D Strategies to Stabilise Greenhouse Gas Atmospheric Concentrations
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