Pulsar Timing Sensitivities to Gravitational Waves from Relativistic Metric Theories of Gravity

Pulsar timing experiments aimed at the detection of gravitational radiation have been performed for decades now. With the forthcoming construction of large arrays capable of tracking multiple millisecond pulsars, it is very likely we will be able to make the first detection of gravitational radiation in the nano-Hertz band, and test Einstein's theory of relativity by measuring the polarization components of the detected signals. Since a gravitational wave predicted by the most general relativistic metric theory of gravity accounts for {\it six} polarization modes (the usual two Einstein's tensor polarizations as well as two vector and two scalar wave components), we have estimated the single-antenna sensitivities to these six polarizations. We find pulsar timing experiments to be significantly more sensitive, over their entire observational frequency band ($\approx 10^{-9} - 10^{-6}$ Hz), to scalar-longitudinal and vector waves than to scalar-transverse and tensor waves. At $10^{-7}$ Hz and with pulsars at a distance of $1$ kpc, for instance, we estimate an average sensitivity to scalar-longitudinal waves that is more than two orders of magnitude better than the sensitivity to tensor waves. Our results imply that a direct detection of gravitational radiation by pulsar timing will result into a test of the theory of general relativity that is more stringent than that based on monitoring the decay of the orbital period of a binary system.Comment: 11 pages, 2 figures. Submitted to Phys. Rev.

Searching for Elko dark matter spinors at the CERN LHC

The aim of this work is to explore the possibility to discover a fermionic field with mass dimension one, the Elko field, in the Large Hadron Collider (LHC). Due to its mass dimension, an Elko can only interact either with Standard Model (SM) spinors and gauge fields at 1-loop order or at tree level through a quartic interaction with the Higgs field. In this Higgs portal scenario, the Elko is a viable candidate to a dark matter constituent which has been shown to be compatible with relic abundance measurements from WMAP and direct dark matter--nucleon searches. We propose a search strategy for this dark matter candidate in the channel $pp \rightarrow l^+ l^- + \not\!\! E_T$ at the $\sqrt{s}=14$ TeV LHC. We show the LHC potential to discover the Elko considering a triple Higgs-Elko coupling as small as $\sim 0.5$ after 1 pb$^{-1}$ of integrated luminosity. Some phenomenological consequences of this new particle and its collider signatures are also discussed.Comment: 7 pages, 3 figure

Constraining Elko Dark Matter at the LHC with Monophoton Events

A mass dimension one fermion, also known as Elko, constitutes a dark matter candidate which might interact with photons at the tree level in a specific fashion. In this work, we investigate the constraints imposed by unitarity and LHC data on this type of interactions using the search for new physics in monophoton events. We found that Elkos which can explain the dark matter relic abundance mainly through electromagnetic interactions are excluded at the 95\%CL by the 8 TeV LHC data for masses up to 1 TeV.Comment: 6 pages, 4 figure

Remote experimentation: integrating research, education, and industrial application

This paper presents a low-cost scaled model of a silo for drying and airing cereal grains. It allows the control and monitor of several parameters associated to the silo's operation, through a remote accessible infrastructure. The scaled model consists of a 2.50 m wide × 2.10 m long plant with all control and monitor capacities provided by micro-Web servers. An application running on the micro-Web servers enables storing all parameters in a data basis for later analysis. The implemented model aims to support a remote experimentation facility for technological education, research-oriented tutorials, and industrial applications. Given the low-cost requirement, this remote facility can be easily replicated in other institutions to support a network of remote labs, which encompasses the concurrent access of several users (e.g. students)

From cheating to teaching: a path for conversion of illegal gambling machines

Video poker machines, a former symbol of fraud and gambling in Brazil, are now being converted into computer-based educational tools for Brazilian public primary schools and also for governmental and non-governmental institutions dealing with communities of poverty and social exclusion, in an attempt to reduce poverty risks (decrease money spent on gambling) and promote social inclusion (increase access and motivation to education). Thousands of illegal gambling machines are seized by federal authorities, in Brazil, every year, and usually destroyed at the end of the criminal apprehension process. This paper describes a project developed by the University of Southern Santa Catarina, Brazil, responsible for the conversion process of gambling machines, and the social inclusion opportunities derived from it. All project members worked on a volunteer basis, seeking to promote social inclusion of Brazilian young boys and girls, namely through digital inclusion. So far, the project has been able to convert over 200 gambling machines and install them in over 40 public primary schools, thus directly benefiting more than 12,000 schoolchildren. The initial motivation behind this project was technology based, however the different options arising from the conversion process of the gambling machines have also motivated a rather innovative and unique experience in allowing schoolchildren and young people with special (educational) needs to access to computer-based pedagogical applications. The availability of these converted machines also helps to place Information and Communication Technologies (ICT) in the very daily educational environment of these children and youngsters, thus serving social and cultural inclusion aspects, by establishing a dialogue with the community and their technological expectations, and also directly contributing to their digital literacy

Seletividade de extrato aquoso de Zingiber officinale [Willd] Roscoe sobre o predador Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinelidae)

Os coleópteros da família Coccinellídeae são predadores de diversas pragas de importância econômica. Cryptolaemus montrouzieri Mulsant é uma espécie exótica no qual foram enviada da Austrália à Califórnia entre 1891-92 por Albert Koeble, para controlar as espécies de cochonilhas que estavam atacando citros (SANCHES et al, 2002). De acordo com Gravena et al. (2006) C. montouzieri é um consumidor generalista e voraz de várias espécies de cochonilha em ambas as fases de larva e adulto. Dentre os predadores de cochonilhas e afídeos, os Coccinelídeos são os mais conhecidos e eficientes, pois uma única larva pode consumir até 250 cochonilhas. O produto fitossanitário ideal, do ponto de vista da produção agrícola e do Manejo Integrado de Pragas, seria aquele que apresentasse seletividade total, isto é, que matasse somente as pragas visadas e preservasse os artrópodes benéficos, evitando, com isso, o desequilíbrio biológico. Os inseticidas comumente utilizados em citros, na sua maioria, são nocivos às joaninhas e outros insetos benéficos que visitam esta cultura (YAMAMOTO e BASSANEZI, 2003). De acordo com Bacci (2001) é de extrema importância que sejam utilizados inseticidas seletivos para a preservação das espécies benéficas no agroecossistema. Apesar da importância da seletividade na preservação do controle biológico natural de pragas, existem ainda poucos estudos a esse respeito.pdf 170

Remote Experimentation supported by Learning Analytics and Recommender Systems

This paper proposes a process based on learning analytics and recommender systems targeted at making suggestions to students about their remote laboratories activities and providing insights to all stakeholders taking part in the learning process. To apply the process, a log with requests and responses of remote experiments from the VISIR project were analyzed. A request is the setup of the experiment including the assembled circuits and the configurations of the measuring equipment. In turn, a response is a message provided by the measurement server indicating measures or an error when it is not possible to execute the experiment. Along the two phases of analysis, the log was analyzed and summarized in order to provide insights about students' experiments. In addition, there is a recommendation service responsible for analyzing the requests thus returning, in case of error, precise information about the assembly of circuits or configurations. The evaluation of the process is consistent in what regards its ability to afford recommendations to the students as they carry out the experiments. Moreover, the summarized information intends to offer teachers means to better understand and develop strategies to scaffold students' learning.info:eu-repo/semantics/publishedVersio

Remote Experimentation supported by Learning Analytics and Recommender Systems

This paper proposes a process based on learning analytics and recommender systems targeted at making suggestions to students about their remote laboratories activities and providing insights to all stakeholders taking part in the learning process. To apply the process, a log with requests and responses of remote experiments from the VISIR project were analyzed. A request is the setup of the experiment including the assembled circuits and the configurations of the measuring equipment. In turn, a response is a message provided by the measurement server indicating measures or an error when it is not possible to execute the experiment. Along the two phases of analysis, the log was analyzed and summarized in order to provide insights about students' experiments. In addition, there is a recommendation service responsible for analyzing the requests thus returning, in case of error, precise information about the assembly of circuits or configurations. The evaluation of the process is consistent in what regards its ability to afford recommendations to the students as they carry out the experiments. Moreover, the summarized information intends to offer teachers means to better understand and develop strategies to scaffold students' learning.info:eu-repo/semantics/publishedVersio