32,153 research outputs found
Orbit decidability, applications and variations
We present the notion of orbit decidability into a more general framework,
exploring interesting generalizations and variations of this algorithmic
problem. A recent theorem by Bogopolski-Martino-Ventura gave a renovated
protagonism to this notion and motivated several interesting algebraic
applications
Sound and complete axiomatizations of coalgebraic language equivalence
Coalgebras provide a uniform framework to study dynamical systems, including
several types of automata. In this paper, we make use of the coalgebraic view
on systems to investigate, in a uniform way, under which conditions calculi
that are sound and complete with respect to behavioral equivalence can be
extended to a coarser coalgebraic language equivalence, which arises from a
generalised powerset construction that determinises coalgebras. We show that
soundness and completeness are established by proving that expressions modulo
axioms of a calculus form the rational fixpoint of the given type functor. Our
main result is that the rational fixpoint of the functor , where is a
monad describing the branching of the systems (e.g. non-determinism, weights,
probability etc.), has as a quotient the rational fixpoint of the
"determinised" type functor , a lifting of to the category of
-algebras. We apply our framework to the concrete example of weighted
automata, for which we present a new sound and complete calculus for weighted
language equivalence. As a special case, we obtain non-deterministic automata,
where we recover Rabinovich's sound and complete calculus for language
equivalence.Comment: Corrected version of published journal articl
Predicted defect induced vortex core switching in thin magnetic nanodisks
We investigate the influence of artificial defects (small holes) inserted
into magnetic nanodisks on the vortex core dynamics. One and two holes
(antidots) are considered. In general, the core falls into the hole but, in
particular, we would like to remark an interesting phenomenon not yet observed,
which is the vortex core switching induced by the vortex-hole interactions. It
occurs for the case with only one hole and for very special conditions
involving the hole size and position as well as the disk size. Any small
deformation in the disk geometry such as the presence of a second antidot
changes completely the vortex dynamics and the vortex core eventually falls
into one of the defects. After trapped, the vortex center still oscillates with
a very high frequency and small amplitude around the defect center.Comment: 11pages, Revtex format, 17 figure
Evaluation of hardening and darkening of common beans during storage by HR-MAS NMR.
Use the NMR to analyze the variation in the metabolic profile of bean cultivars stored at controlled temperatures and modified atmosphere. Establishing the correlation between the metabolic variation with darkening and hardening grains proposing the best storage condition
Avaliação Radiográfica das Iatrogenias Ocorridas Durante a Realização de Tratamentos Endodônticos Por Alunos de Graduação
O objetivo do presente estudo foi determinar, por meio de radiografias periapicais, a frequência de iatrogenias ocorridas durante o preparo mecânico dos tratamentos endodônticos realizados por alunos de Odontologia da UFES, na disciplina de Endodontia II, durante o período de 2012 a 2014. Registros radiográficos provenientes de 397 dentes unirradiculares e birradiculares tratados endodonticamente, foram selecionados e analisados por três avaliadores especialistas em Endodontia, por meio da projeção das imagens radiográficas. As iatrogenias foram avaliadas de acordo com os seguintes critérios: perfuração (radicular, apical e de furca), perfuração em rasgo, instrumento fraturado, degrau e zip. A seguir, os dentes foram classificados em função da ausência ou presença de iatrogenias em adequados ou inadequados, respectivamente. Nos casos de comparações entre percentuais, foi utilizado o teste para proporções (Qui-quadrado). De acordo com os resultados, 7,3% dos dentes foram considerados inadequados e não houve diferença estatística significante entre os grupos anteriores, incisivos e caninos (p>0,05). O degrau estava presente em 6,54% dos canais radiculares, o zip em 0,75% dos canais radiculares e apenas em um canal radicular foi detectado instrumento fraturado. Em dentes com curvaturas moderadas, a curvatura radicular foi um possível fator que influenciou a ocorrência do degrau (p<0,05). Conclui-se que a maioria dos preparos dos canais radiculares foram considerados adequados em função da baixa frequência de iatrogenias nos tratamentos endodônticos realizados pelos alunos da Universidade Federal do Espírito Santo
Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production
We outline the case for heavy-ion-physics studies using the multi-TeV lead
LHC beams in the fixed-target mode. After a brief contextual reminder, we
detail the possible contributions of AFTER@LHC to heavy-ion physics with a
specific emphasis on quarkonia. We then present performance simulations for a
selection of observables. These show that , and
production in heavy-ion collisions can be studied in new energy and
rapidity domains with the LHCb and ALICE detectors. We also discuss the
relevance to analyse the Drell-Yan pair production in asymmetric
nucleus-nucleus collisions to study the factorisation of the nuclear
modification of partonic densities and of further quarkonia to restore their
status of golden probes of the quark-gluon plasma formation.Comment: 18 pages, 7 figure
Adverse Events among HIV/MDR-TB Co-Infected Patients Receiving Antiretroviral and Second Line Anti-TB Treatment in Mumbai, India.
Significant adverse events (AE) have been reported in patients receiving medications for multidrug- and extensively-drug-resistant tuberculosis (MDR-TB & XDR-TB). However, there is little prospective data on AE in MDR- or XDR-TB/HIV co-infected patients on antituberculosis and antiretroviral therapy (ART) in programmatic settings
Detecting New Physics from CP-violating phase measurements in B decays
The standard CKM model can be tested and New Physics detected using only
CP-violating phase measurements in B decays. This requires the measurement of a
phase factor which is small in the Standard Model, in addition to the usual
large phases and . We also point out that identifying
violations of the unitarity of the CKM matrix is rather difficult, and cannot
be done with phase measurements alone.Comment: 6 pages, Latex, no figure
Underground parallel pipelines domino effect: An analysis based on pipeline crater models and historical accidents
This paper focuses on the analysis of the possibility of domino effect in underground parallel pipelines relying on historical accident data and pipeline crater models. An underground pipeline can be considered as safe following an accident with an adjacent gas or liquefied pipeline when it remains outside the ground crater generated. In order to prevent the domino effect in these cases, the design of parallel pipelines has to consider adequate pipeline separations based on the crater width, which is one of the widely used methods in engineering applications. The objective of this work is the analysis of underground petroleum product pipelines ruptures with the formation of a ground crater as well as the evaluation of possible domino effects in these cases. A detailed literature survey has been carried out to review existing crater models along with a historical analysis of past accidents. A FORTRAN code has been implemented to assess the performance of the Gasunie, the Batelle and the Advantica crater models. In addition to this, a novel Accident-Based crater model has been presented, which allows the prediction of the crater width as a function of the relevant design pipeline parameters as well as the soil density. Modifications have also been made to the Batelle and Accident-Based models in order to overcome the underestimation of the crater width. The calculated crater widths have been compared with real accident data and the performance evaluation showed that the proposed Accident-Based model has a better performance compared to other models studied in this work. The analysis of forty-eight past accidents indicated a major potential of underground parallel pipelines domino effect which is proven by two real cases taken from the literature. Relying on the investigated accidents, the crater width was smaller than or equal to 20 m in most cases indicating that the definition of underground pipeline separations at around 10 m would be sufficient to ensure a small probability of the domino effect
Minimal 3-3-1 model, lepton mixing and muonium-antimuonium conversion
The recent experimental results on neutrino oscillation and on
muonium-antimuonium conversion require extension of the minimal 3-3-1 model. We
review the constraints imposed to the model by those measurements and suggest a
pattern of leptonic mixing, with charged leptons in a non-diagonal basis, which
accounts for the neutrino physics and circumvents the tight muonium-antimuonium
bounds on the model. We also illustrate a scenario where this pattern could be
realized.Comment: 4 pages; abbreviated version, conclusions unchange
- …