Desulfurization of coal prior to combustion has developed the need for an accurate technique to determine which sulfur groups are present before and after chemical treatment. Atmospheric ...pressure−temperature programmed reduction (AP-TPR) is a technique that can determine the sulfur distribution by using model compounds as calibrants. This study deals with a series of model compounds for oxidized sulfur functionalities. It is proven by AP-TPR and AP-TPR-MS that the sulfur groups of these model compounds are decomposed and that decomposition products (SO/SO2) are only partially reduced. Diaryl sulfoxides and sulfones are found to be more stable than their aryl alkyl-substituted counterparts, and sulfones are more stable than the structurally related sulfoxides. Sulfates are generally found to be the most stable oxidized forms of sulfur.
We address the question of the existence of bound states for a suitably projected two-dimensional massless Dirac operator in the presence of a Bessel-Macdonald potential (also known as ...\(K_0\)-potential potential), raised by De Lima, Del Cima and Miranda, in Eur.Phys.J. B (2020) 93, 187. Based on Relativistic Hardy Inequality, we prove that this operator has no bound states if \(\gamma \leqslant \gamma_{\rm crit}\) (subcritical region), where \(\gamma\) is a coupling constant.
The Brown-Ravenhall operator was initially proposed as an alternative to describe the fermion-fermion interaction via Coulomb potential and subject to relativity. This operator is defined in terms of ...the associated Dirac operator and the projection onto the positive spectral subspace of the free Dirac operator. In this paper, we propose to analyze a modified version of the Brown-Ravenhall operator in two-dimensions. More specifically, we consider the Brown-Ravenhall operator with a short-range attractive potential given by a Bessel-Macdonald function (also known as \(K_0\)-potential) using the Foldy-Wouthuysen unitary transformation. Initially, we prove that the two-dimensional Brown-Ravenhall operator with \(K_0\)-potential is bounded from below when the coupling constant is below a specified critical value (a property also referred to as stability). A major feature of this model is the fact that it does not cease to be bounded below even if the coupling constant is above the specified critical value. We also investigate the nature of the spectrum of this operator, in particular the location of the essential spectrum, and the existence of eigenvalues, which are either isolated from the essential spectrum or embedded in it.
The present study aimed to evaluate the effect of alkaline treatments with urea, NaOH and Ca(OH)2 on chemical composition and in situ ruminal degradability of dry matter, crud protein and neutral ...detergent fiber of sugarcane tip hay. Samples were incubated in the rumen of three cannulated cattle for up to 72 hours in a split plot randomized block design. Ammoniation with 6% urea increased (p<0.05) the crude protein content by 13% and reduced the neutral detergent fiber and insoluble nitrogen content of the hay. When treated with the highest doses of the compounds, there was a high potential degradability of dry matter, crude protein and neutral detergent fiber, and a shorter neutral detergent fiber lag time. Ammoniation with urea promotes a reduction in the content of NDF, hemicellulose and insoluble nitrogen, with an increase in the content of CP in the hay, with emphasis for the level of 6% urea. The ruminal degradation of sugarcane tip hay increases with alkaline treatments using 6% urea or 3% NaOH, however, ammoniation with urea is indicated for the treatment of hay, as this is low cost and can be easily adopted by farmers in the semiarid region.
The Gerda 1 and Majorana 2 projects, both searching for the neutrinoless double beta-decay of 76Ge, are developing a joint Monte-Carlo simulation framework called MaGe. Such an approach has many ...benefits: the workload for the development of general tools is shared between more experts, the code is tested in more detail, and more experimental data is made available for validation.
Objective To evaluate the preoperative presence of C-reactive protein (CRP) and troponin T(hs-TnT) in patients with coronary artery disease (CAD) undergoing cardiopulmonary bypass (CPB) in order to ...better clarify the role of atrial inflammation and/or myocardial ischemia in the development of postoperative atrial fibrillation (POAF). Design Prospective, nonrandomized study. Setting University hospital. Participants Thirty-eight consecutive ischemic patients admitted to the authors’ hospital for CAD undergoing elective on-pump coronary artery bypass grafting (CABG). Intervention Elective on-pump CABG. Measurements and Main Results Peripheral blood samples were collected from all patients before and 24 hours after CABG to assess high sensitive (hs)-CRP and troponin T (hs-TnT) levels. The patients’ heart rhythm was monitored by continuous ECG telemetry. Biopsies from the right atrial appendage were obtained at the beginning of the CABG procedure in order to perform immunohistochemistry for CRP and reverse transcription polymerase chain reaction for CRP mRNA expression. Fourteen patients out of 38 (36%) developed POAF. Atrial CRP was found in 31 patients (82%), 10 with POAF and 21 with sinus rhythm (71% v 87% respectively, p = ns). None of the atrial samples was positive for CRP mRNA. Atrial CRP did not correlate with serum hs-CRP levels and with occurrence of POAF, but with the incidence of diabetes (p = 0.010). Postoperative hs-TnT levels, but not hs-CRP levels, were identified as the only predictor of POAF occurrence (p = 0.016). Conclusions In patients undergoing CABG, neither peripheral nor tissue preoperative CRP levels, but only postoperative hs-TnT levels, correlated with POAF, suggesting the primary role of an ischemic trigger of atrial fibrillation.
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