Search results for "Diss"

Quantum transport and the phase space structure of the Wightman functions

2019

We study the phase space structure of exact quantum Wightman functions in spatially homogeneous, temporally varying systems. In addition to the usual mass shells, the Wightman functions display additional coherence shells around zero frequency $k_0=0$, which carry the information of the local quantum coherence of particle-antiparticle pairs. We find also other structures, which encode non-local correlations in time, and discuss their role and decoherence. We give a simple derivation of the cQPA formalism, a set of quantum transport equations, that can be used to study interacting systems including the local quantum coherence. We compute quantum currents created by a temporal change in a par…

Non-equilibrium dynamics of a scalar field with quantum backreaction

2021

We study the dynamical evolution of coupled one- and two-point functions of a scalar field in the 2PI framework at the Hartree approximation, including backreaction from out-of-equilibrium modes. We renormalize the 2PI equations of motion in an on-shell scheme in terms of physical parameters. We present the Hartree-resummed renormalized effective potential at finite temperature and critically discuss the role of the effective potential in a non-equilibrium system. We follow the decay and thermalization of a scalar field from an initial cold state with all energy stored in the potential, into a fully thermalized system with a finite temperature. We identify the non-perturbative processes of …

Momentum anisotropy effects for quarkonium in a weakly coupled quark-gluon plasma below the melting temperature

2017

In the early stages of heavy-ion collisions, the hot QCD matter expands more longitudinally than transversely. This imbalance causes the system to become rapidly colder in the longitudinal direction and a local momentum anisotropy appears. In this paper, we study the heavy-quarkonium spectrum in the presence of a small plasma anisotropy. We work in the framework of pNRQCD at finite temperature. We inspect arrangements of non-relativistic and thermal scales complementary to those considered in the literature. In particular, we consider temperatures larger and Debye masses smaller than the binding energy, which is a temperature range relevant for presently running LHC experiments. In this set…

Robotic transanal total mesorectal excision: Is the future now?

2021

Total mesorectal excision (TME) is the standard surgical treatment for the curative radical resection of rectal cancers. Minimally invasive TME has been gaining ground favored by the continuous technological advancements. New procedures, such as transanal TME (TaTME), have been introduced to overcome some technical limitations, especially in low rectal tumors, obese patients, and/or narrow pelvis. The earliest TaTME reports showed promising results when compared with the conventional laparoscopic TME. However, recent publications raised concerns regarding the high rates of anastomotic leaks or local recurrences observed in national series. Robotic TaTME (R-TaTME) has been proposed as a nove…

2020

The Internet has become one of the main sources of information for university students’ learning. Since anyone can disseminate content online, however, the Internet is full of irrelevant, biased, or even false information. Thus, students’ ability to use online information in a critical-reflective manner is of crucial importance. In our study, we used a framework for the assessment of students’ critical online reasoning (COR) to measure university students’ ability to critically use information from online sources and to reason on contentious issues based on online information. In addition to analyzing students’ COR by evaluating their open-ended short answers, we also investigated the stude…

Coulomb dissociation of 27P

2011

International audience; In this work the astrophysical 26Si(p,γ)27P reaction is studied using the Coulomb dissociation technique. We performed a 27P Coulomb Dissociation experiment at GSI, Darmstadt (28 May-5 June 2007) using the ALADIN-LAND setup which allows complete-kinematic studies. A secondary 27P beam at 498 AMeV impinging a 515mg/cm2 Pb target was used. The relative energy of the outgoing system (26Si+p) is measured obtaining the resonant states of the 27P. Preliminary results show four resonant states measured at 0.36±0.07, 0.88±0.09, 1.5±0.2, 2.3±0.3 MeV and evidence of a higher state at around 3.1 MeV. The preliminary total cross section obtained for relative energies between 0 a…

Experimental study of the 15O(2p, γ)17Ne cross section by Coulomb Dissociation for the rp process

2016

6th Nuclear Physics in Astrophysics Conference (NPA), Lisbon, Portugal, 19 May 2013 - 24 May 2013; Journal of physics / Conference Series 665, 012046 (2016). doi:10.1088/1742-6596/665/1/012046

Before newspapers and the telegraph: information distribution in Livland more than two hundred years ago

2020

This paper concerns information dissemination in the Livland province of the Russian Empire at the turn of the eighteenth and the nineteenth centuries, when its rulers sent their orders to the provincial capital, Riga, by horse post. In Riga they were translated into German, and the ancient network of information dissemination used by the Lutheran Church was engaged. The orders of both the Empire and provincial rulers were delivered to Lutheran pastors, who announced this information to their parishes from the pulpit, speaking in Latvian or Estonian so as to be understood by local peasants (serfs), and allowed the texts to circulate around the manors of the parish. The infrastructure of th…

Theoretical investigations of nitrogen doping on Co 3 O 4 for water dissociation catalytically activity

2018

We report the results of theoretical investigations of nitrogen doping on Co 3 O 4 (100) bulk by means of the plane-wave periodic density functional theory (DFT) calculations combined with the Hubbard-U approach and statistical thermodynamics.Using accurate DFT+U calculations, we have shown that bulk Co ions denote charges in value 0.017 - 0.57e. For further water adsorption process studies was selected structures with most changes in charges in Co ions: (3) structure for n = 25%, (2) structure forn = 12.5% and structure for (1) structure.

From Nazi holocaust to nuclear holocaust: a lesson to learn?

1986

In a 1986 address to the International Physicians for the Prevention of Nuclear War, a German physician describes his profession's embrace of National Socialism. The nationalistic sentiments of German scientists led them to identify with the goals of the Third Reich and to participate in its programs. He gives examples of physician involvement in the Nazi Party, discrimination against "non-Aryan" doctors, "eugenic" mass murder, and lethal experiments with human subjects. The few who protested were regarded as traitors by the profession as a whole, and post-war apologists argue that physicians' organizations had no choice but to collaborate with the Nazis. Hanauske-Abel rejects this reasonin…