Effects on the Non-Relativistic Dynamics of a Charged Particle Interacting with a Chern-Simons Potential

The hydrogen atom in two dimensions, described by a Schr\"odinger equation with a Chern-Simons potential, is numerically solved. Both its wave functions and eigenvalues were determined for small values of the principal quantum number $n$. The only possible states correspond to $l=0$. How the result depends on the topological mass of the photon is also discussed. In the case $n=1$, the energy of the fundamental state corresponding to different choice for the photon mass scale are found to be comprehended in the interval $-3,5 \times 10^{-3} eV \leq E \leq -9,0 \times 10^{-2} eV$, corresponding to a mean radius of the electron in the range $(5.637 \pm 0.005) \times 10^{-8}$~cm $\leq \leq (48.87 \pm 0.03) \times 10^{-8}$~cm. In any case, the planar atom is found to be very weekly bounded showing some features similar to the Rydberg atoms in three dimensions with a Coulombian interaction.Comment: 6 pages, 5 figure

A PENDULUM-BASED MODEL FOR FLUID STRUCTURE INTERACTION ANALYSES

In the present contribution a pendulum-based model is used to represent fluid-structure interactions. For this purpose, a theoretical and experimentalanalysis of the dynamic behavior of a viscously damped spherical non rotational single-degree-of-freedom pendulum was performed. The dampingprocess is characterized according to two different regimes: in the first, it can be seen as a viscous low Reynolds’ number flow and, in the second, it can be considered as a viscously damped system. The pendulum was tested experimentally in a large reservoir containing a Newtonian fluid for validation purposes and good agreement was found between numerical and experimental results

Efeito de extractos de raízes eliciadas de Castanea sativa no crescimento do fungo ectomicorrízico Pisolithus tinctorius

O castanheiro (Castanea sativa Mill.) estabelece associação com numerosas espécies de fungos ectomicorrízicos, estando descritos os efeitos benéficos para a planta após micorrização com Pisolithus tinctorius. Neste processo é essencial que ocorra a troca de sinais entre os simbiontes, para que seja reconhecida a sua compatibilidade e para que ocorra a formação dos órgãos ectomicorrízicos. Neste trabalho são fornecidas evidências que sugerem a capacidade de extractos de raízes de castanheiro, nos estádios iniciais de contacto com P. tinctorius regularem o crescimento do fungo micorrízico

Morphology and strength of acrylonitrile butadiene styrene welds performed by robotic friction stir welding

The aim of this study is to examine the main factors affecting friction stir welding (FSW) of acrylonitrile butadiene styrene (ABS) plates, performed by a robotic system developed to this purpose. Welds were carried out using a tool with stationary shoulder and an external heating system. The welding parameters studied were the axial force, rotational and traverse speeds and temperature of the tool. The major novelty is to perform FSW of a polymer in a robotic system and to study the influence of the axial force on weld quality. In a robotic solution the control of axial force allows to eliminate robot positional errors and guarantee the contact between the FSW tool and the work pieces. Strength and strain properties of the welds are evaluated and correlated with the morphology of the welded zone. A comparison between welds produced in the robotic FSW system and in a dedicated FSW machine is presented. It is shown the feasibility of robotic FSW of ABS without deteriorating the mechanical properties of the welds in relation to those produced in the dedicated FSW machine

JCML: A specification language for the runtime verification of Java Card programs

AbstractJava Card is a version of Java developed to run on devices with severe storage and processing restrictions. The applets that run on these devices are frequently intended for use in critical, highly distributed, mobile conditions. They are required to be portable and safe. Often, the requirements of the application impose the use of dynamic, on-card verifications, but most of the research developed to improve the safety of Java Card applets concentrates on static verification methods. This work presents a runtime verification approach based on Design by Contract to improve the safety of Java Card applications. To this end, we propose JCML (Java Card Modelling Language) a specification language derived from JML (Java Modelling Language) and its implementation: a compiler that generates runtime verification code. We also present some experiments and quality indicators. This paper extends previous published work from the authors with a more complete and precise definition of the JCML language and new experiments and results

Modeling chronic pain experiences from online reports using the Reddit Reports of Chronic Pain dataset

Objective: Reveal and quantify qualities of reported experiences of chronic pain on social media, from multiple pathological backgrounds, by means of the novel Reddit Reports of Chronic Pain (RRCP) dataset, using Natural Language Processing techniques. Materials and Methods: Define and validate the RRCP dataset for a set of subreddits related to chronic pain. Identify the main concerns discussed in each subreddit. Model each subreddit according to their main concerns. Compare subreddit models. Results: The RRCP dataset comprises 86,537 Reddit submissions from 12 subreddits related to chronic pain (each related to one pathological background). Each RRCP subreddit has various main concerns. Some of these concerns are shared between multiple subreddits (e.g., the subreddit Sciatica semantically entails the subreddit backpain in their various concerns, but not the other way around), whilst some concerns are exclusive to specific subreddits (e.g., Interstitialcystitis and CrohnsDisease). Discussion: These results suggest that the reported experience of chronic pain, from multiple pathologies (i.e., subreddits), has concerns relevant to all, and concerns exclusive to certain pathologies. Our analysis details each of these concerns and their similarity relations. Conclusion: Although limited by intrinsic qualities of the Reddit platform, to the best of our knowledge, this is the first research work attempting to model the linguistic expression of various chronic pain-inducing pathologies and comparing these models to identify and quantify the similarities and differences between the corresponding emergent chronic pain experiences.Comment: 24 pages, 26 figures, 8 table