23,433 research outputs found
Probing quantum fluctuation theorems in engineered reservoirs
Fluctuation Theorems are central in stochastic thermodynamics, as they allow
for quantifying the irreversibility of single trajectories. Although they have
been experimentally checked in the classical regime, a practical demonstration
in the framework of quantum open systems is still to come. Here we propose a
realistic platform to probe fluctuation theorems in the quantum regime. It is
based on an effective two-level system coupled to an engineered reservoir, that
enables the detection of the photons emitted and absorbed by the system. When
the system is coherently driven, a measurable quantum component in the entropy
production is evidenced. We quantify the error due to photon detection
inefficiency, and show that the missing information can be efficiently
corrected, based solely on the detected events. Our findings provide new
insights into how the quantum character of a physical system impacts its
thermodynamic evolution.Comment: 9 pages, 4 figure
Detection of Exotic Massive Hadrons in Ultra High Energy Cosmic Ray Telescopes
We investigate the detection of exotic massive strongly interacting hadrons
(uhecrons) in ultra high energy cosmic ray telescopes. The conclusion is that
experiments such as the Pierre Auger Observatory have the potential to detect
these particles. It is shown that uhecron showers have clear distinctive
features when compared to proton and nuclear showers. The simulation of uhecron
air showers, and its detection and reconstruction by fluorescence telescopes is
described. We determine basic cuts in observables that will separate uhecrons
from the cosmic ray bulk, assuming this is composed by protons. If these are
composed by heavier nucleus the separation will be much improved. We also
discuss photon induced showers. The complementarity between uhecron detection
in accelerator experiments is discussed.Comment: 9 page 9 figure
Probing the two-scale-factor universality hypothesis by exact rotation symmetry-breaking mechanism
We probe the two-scale factor universality hypothesis by evaluating, firstly
explicitly and analytically at the one-loop order, the loop quantum corrections
to the amplitude ratios for O() scalar field theories with
rotation symmetry-breaking in three distinct and independent methods in which
the rotation symmetry-breaking mechanism is treated exactly. We show that the
rotation symmetry-breaking amplitude ratios turn out to be identical in the
three methods and equal to their respective rotation symmetry-breaking ones,
although the amplitudes themselves, in general, depend on the method employed
and on the rotation symmetry-breaking parameter. At the end, we show that all
these results can be generalized, through an inductive process based on a
general theorem emerging from the exact calculation, to any loop level and
physically interpreted based on symmetry ideas.Comment: 17 pages, 3 figure
Protocolo modificado para extração de DNA do gênero Pestalotiopsis.
Objetivou-se com este trabalho modificar o protocolo de extração de DNA do gênero Pestalotiopsis. Foram obtidos 200 mg de micélio de 11 isolados de Pestalotiopsis sp. O protocolo de extração proposto por Joshi (2009) foi modificado e testado retirando-se o fenol no processo de desproteinização do DNA. A quantidade de DNA genômico extraído foi quantificada em fotodocumentador e a qualidade do DNA final foi avaliada em gel 0,9% de agarose e em reações de marcadores RAPD. A metodologia sem o emprego do fenol proporcionou quantidade satisfatória (32,55 a 49,92 ng/µL) e pureza de DNA para caracterização molecular do fungo. O protocolo modificado, portanto, pode ser utilizado para extrair DNA do gênero Pestalotiopsis com eficiência do método e segurança para os usuários
Magnetic phases evolution in the LaMn1-xFexO3+y system
We have investigated the crystal structure and magnetic properties for
polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0,
prepared by solid state reaction in air. All samples show the ORT-2
orthorhombic structure that suppresses the Jahn-Teller distortion, thus
favoring a ferromagnetic (FM) superexchange (SE) interaction between
Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in
the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82%
of the usual Mn^{3+} ions, with possible double exchange interaction between
them. The Fe doping in this system is known to produce only stable Fe^{3+}
ions. We find an evolution from a fairly strong FM phase with a Curie
temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with
T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass
behavior. For intermediate Fe contents a mixed-phase state occurs, with a
gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic
transition broadening for 0.2 < x < 0.7. A model based on the expected exchange
interaction among the various magnetic-ion types, accounts very well for the
saturation-magnetization dependence on Fe doping.Comment: 27 pages, 9 figure
Manejo e controle da Cochonilha Ortézia (Orthezia praelonga), em plantios irrigados de acerola, no Submédio São Francisco.
O cultivo da acerola é uma importante alternativa econômica para a Região Nordeste do Brasil. No Submédio São Francisco, há cerca de mil hectares cultivados e a expansão do cultivo deve-se, basicamente, ao apreciado sabor da fruta e ao alto teor de ácido ascórbico (vitamina C), que, em algumas variedades, alcança até 5.000 miligramas por 100 gramas de polpa.bitstream/CPATSA/37176/1/CTE83.pd
Influence of culture media on the physical and chemical properties of Ag–TiCN coatings
The aim of this study was to verify the possible physical and chemical changes that may occur on the surface of Ag–TiCN coatings after exposure to the culture media used in microbiological and cytotoxic assays, respectively tryptic soy broth (TSB) and Dulbecco's modified eagle's medium (DMEM). After sample immersion for 24 h in the media, analyses were performed by glow discharge optical emission spectroscopy discharge radiation (GDOES), Rutherford backscattering spectroscopy (RBS) and x-ray photoelectron spectroscopy (XPS). The results of GDOES profile, RBS and XPS spectra, of samples immersed in TSB, demonstrated the formation of a thin layer of carbon, oxygen and nitrogen that could be due to the presence of proteins in TSB. After 24 h of immersion in DMEM, the results showed the formation of a thin layer of calcium phosphates on the surface, since the coatings displayed a highly oxidized surface in which calcium and phosphorus were detected. All these results suggested that the formation of a layer on the coating surface prevented the release of silver ions in concentrations that allow antibacterial activity.IC acknowledges the financial support of FCT-Fundacao para a Ciencia e a Tecnologia through the grant SFRH/BD/67022/2009. REG acknowledges support from Ramon y Cajal programme (RyC2007-0026). This research is sponsored by FEDER funds through the program COMPETE-Programa Operacional Factores de Competitividade and by national funds through FCT-Fundacao para a Ciencia e a Tecnologia in the framework of the Strategic Projects PESTC/FIS/UI607/2011, PEST-C/EME/UI0285/2011, PTDC/CTM/102853/2008.The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project 'BioHealth-Biotechnology and Bioengineering approaches to improve health quality', Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. The authors also thank the project 'Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB', Ref. FCOMP-01-0124-FEDER-027462
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