2,581 research outputs found
Preliminary investigation on auto-thermal extrusion of ground tire rubber
Ground tire rubber (GTR) was processed using an auto-thermal extrusion as prerequisite to green reclaiming of GTR. The reclaimed GTR underwent a series of tests: thermogravimetric analysis combined with Fourier-transform infrared spectroscopy (TGA-FTIR), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and static headspace and gas chromatography-mass spectrometry (SHS-GC-MS) in order to evaluate the impact of barrel heating solution (with/without external barrel heating) on reclaiming process of GTR. Moreover, samples were cured to assess the impact of reclaiming heating solution on curing characteristics and physico-mechanical properties. Detailed analysis of the results indicated that the heat supplied by the machinery was replaced by energy generated due to the high shearing phenomenon, what significantly influenced energy consumption and hereby lowered processing costPostprint (published version
Mehrsprachigkeit und Methode: Der Umgang mit dem sprachlichen Egalitätsprinzip im Unionsrecht
Ferromagnetism in one-dimensional metals: breakdown of the Hartree-Fock approximation and possible first order phase transition
We calculate the Gibbs potential Gamma (M) of a one-dimensional metal at
constant magnetization M to second order in the screened electron-electron
interaction U. At zero temperature we find that Gamma (M) contains non-analytic
corrections proportional to M^2 \ln | M| and | M |^3, implying that a possible
paramagnetic-ferromagnetic quantum phase transition in one-dimensional metals
must be first order.Comment: 8 pages, 7 figures; we have changed our choice of the ultraviolet
cutoff, as suggested by a referee. Phase transition occurs now for Stoner
factor smaller than unity. Fig 5 and Fig.7 are have been redraw
Investigating the impact of curing system on structure-property relationship of natural rubber modified with brewery by-product and ground tire rubber
The application of wastes as a filler/reinforcement phase in polymers is a new strategy to modify the performance properties and reduce the price of biocomposites. The use of these fillers, coming from agricultural waste (cellulose/lignocellulose-based fillers) and waste rubbers, constitutes a method for the management of post-consumer waste. In this paper, highly-filled biocomposites based on natural rubber (NR) and ground tire rubber (GTR)/brewers’ spent grain (BSG) hybrid reinforcements, were prepared using two different curing systems: (i) sulfur-based and (ii) dicumyl peroxide (DCP). The influence of the amount of fillers (in 100/0, 50/50, and 0/100 ratios in parts per hundred of rubber) and type of curing system on the final properties of biocomposites was evaluated by the oscillating disc rheometer, Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, swelling behavior, tensile testing, and impedance tube measurements. The results show, that the scorch time and the optimum curing time values of sulfur cured biocomposites are affected by the change of the hybrid filler ratio while using the DCP curing system, and the obtained values do not show significant variations. The results conclude that the biocomposites cured with sulfur have better physico-mechanical and acoustic absorption, and that the type of curing system does not influence their thermal stability. The overall analysis indicates that the difference in final properties of highly filled biocomposites cured with two different systems is mainly affected by the: (i) cross-linking efficiency, (ii) partial absorption and reactions between fillers and used additives, and (iii) affinity of additives to applied fillersPostprint (published version
Emotion in the German Lutheran Baroque and the development of subjective time consciousness
This study examines some of the ways in which it was possible to understand emotion in Lutheran church music of the seventeenth and early eighteenth centuries. It suggests that emotion related to music more through association and contextual factors than through a fixed relationship, thus explaining the ways in which musical passages and techniques could be taken from a secular context to serve a sacred purpose. With these factors in mind, it is possible to suggest ways in which a listener's likely emotional association with music can be harnessed through particular compositional procedures. Schütz's setting of part of the Song of Songs may well engage with the listener's consciousness over time, stretching it and reinforcing the ‘useful’ emotional associations that the sacred context might bring. The opening aria of Bach's cantata ‘Liebster Jesu, mein Verlangen’ achieves something similar over a longer span and with greater emotional intensity. Here there is the added sense of the believer finding, losing and then rediscovering the object of spiritual adoration. The music thus implies the potential alienation of the listener, something both supported and overcome through the very structuring of the music. Its repetitive ritornello process is sometimes hidden but always latent, thus playing on the potential for subconscious recognition. Together, these two examples suggest that music can be used as a powerful demonstration of the historical development of modern forms of consciousness as related to emotional states over time
Polynomial Chaos-based Bayesian Inference of K-Profile Parametrization in a General Circulation Model of the Tropical Pacific
The authors present a Polynomial Chaos (PC)-based Bayesian inference method
for quantifying the uncertainties of the K-Profile Parametrization (KPP) within
the MIT General Circulation Model (MITgcm) of the tropical pacific. The
inference of the uncertain parameters is based on a Markov Chain Monte Carlo
(MCMC) scheme that utilizes a newly formulated test statistic taking into
account the different components representing the structures of turbulent
mixing on both daily and seasonal timescales in addition to the data quality,
and filters for the effects of parameter perturbations over those due to
changes in the wind. To avoid the prohibitive computational cost of integrating
the MITgcm model at each MCMC iteration, we build a surrogate model for the
test statistic using the PC method. To filter out the noise in the model
predictions and avoid related convergence issues, we resort to a
Basis-Pursuit-DeNoising (BPDN) compressed sensing approach to determine the PC
coefficients of a representative surrogate model. The PC surrogate is then used
to evaluate the test statistic in the MCMC step for sampling the posterior of
the uncertain parameters. Results of the posteriors indicate good agreement
with the default values for two parameters of the KPP model namely the critical
bulk and gradient Richardson numbers; while the posteriors of the remaining
parameters were barely informative
Systematic Perturbation Theory for Dynamical Coarse-Graining
We demonstrate how the dynamical coarse-graining approach can be
systematically extended to higher orders in the coupling between system and
reservoir. Up to second order in the coupling constant we explicitly show that
dynamical coarse-graining unconditionally preserves positivity of the density
matrix -- even for bath density matrices that are not in equilibrium and also
for time-dependent system Hamiltonians. By construction, the approach correctly
captures the short-time dynamics, i.e., it is suitable to analyze non-Markovian
effects. We compare the dynamics with the exact solution for highly
non-Markovian systems and find a remarkable quality of the coarse-graining
approach. The extension to higher orders is straightforward but rather tedious.
The approach is especially useful for bath correlation functions of simple
structure and for small system dimensions.Comment: 17 pages, 5 figures, version accepted for publication in PR
The potential role of T-cells and their interaction with antigen-presenting cells in mediating immunosuppression following trauma-hemorrhage
Objective: Trauma-hemorrhage results in depressed immune responses of antigen-presenting cells (APCs) and T-cells. Recent studies suggest a key role of depressed T-cell derived interferon (IFN)-g in this complex immune cell interaction. The aim of this study was to elucidate further the underlying mechanisms responsible for dysfunctional T-cells and their interaction with APCs following trauma-hemorrhage.
Design: Adult C3H/HeN male mice were subjected to trauma-hemorrhage (3-cm midline laparotomy) followed by hemorrhage (blood pressure of 35�5mmHg for 90 min and resuscitation) or sham operation. At 24 h thereafter, spleens were harvested and T-cells (by Microbeads) and APCs (via adherence) were Isolated. Co-cultures of T-cells and APCs were established for 48 h and stimulated with concanavalin A and lipopolysaccharide. T-Cell specific cytokines known to affect APC function (i.e. interleukin(IL)-2, IL-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF)) were measured in culture supernatants by Multiplex assay. The expression of MHC class II as well as co-stimulatory surface molecules on T-cells and APCs was determined by flow cytometry.
Results: The release of IL-4 and GM-CSF by T-cells was suppressed following trauma-hemorrhage, irrespective of whether sham or trauma-hemorrhage APCs were present. Antigen-presenting cells from animals subjected to trauma-hemorrhage did not affect T-cell derived cytokine release by sham T-cells. In contrast, T-cells from traumahemorrhage animals depressed MHC class II expression of CD11c(þ) cells, irrespective of whether APCs underwent sham or trauma-hemorrhage procedure. Surprisingly, co-stimulatory molecules on APCs (CD80, CD86) were not affected by trauma-hemorrhage.
Conclusions: These results suggest that beside IFN-g other T-cell derived cytokines contribute to immunosuppression following trauma-hemorrhage causing diminished MHC II expression on APCs. Thus, T-cells appear to play an important role in this interaction at the time-point examined. Therapeutic approaches should aim at maintenance of T-cell function and their interaction with APCs to prevent extended immunosuppression following trauma-hemorrhage
Die meterologischen Bedingungen der Ausbreitung luftfremder Stoffe in Ispra/Italien bei den Reaktoren der Euratom. EUR 3167. = Meteorological conditions governing the propogration of air-contaminating substances released from the Euratom reactors at Ispra, Italy. EUR 3167.
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