First in-beam studies of a Resistive-Plate WELL gaseous multiplier

We present the results of the first in-beam studies of a medium size (10$\times$10 cm$^2$) Resistive-Plate WELL (RPWELL): a single-sided THGEM coupled to a pad anode through a resistive layer of high bulk resistivity ($\sim$10$^9 \Omega$cm). The 6.2~mm thick (excluding readout electronics) single-stage detector was studied with 150~GeV muons and pions. Signals were recorded from 1$\times$1 cm$^2$ square copper pads with APV25-SRS readout electronics. The single-element detector was operated in Ne\(5% $\mathrm{CH_{4}}$) at a gas gain of a few times 10$^4$, reaching 99$\%$ detection efficiency at average pad multiplicity of $\sim$1.2. Operation at particle fluxes up to $\sim$10$^4$ Hz/cm$^2$ resulted in $\sim$23$\%$ gain drop leading to $\sim$5$\%$ efficiency loss. The striking feature was the discharge-free operation, also in intense pion beams. These results pave the way towards robust, efficient large-scale detectors for applications requiring economic solutions at moderate spatial and energy resolutions.Comment: Accepted by JINS

Chromosome variations and diversity of Epidendrum ibaguense Lindl. (Orchidaceae) on the Tepequém's Tepuy, Roraima, Brazil.

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Morphometric patterns and preferential uses of Capsicum peppers in the State of Roraima, Brazilian Amazonia.

O objetivo deste estudo foi verificar distinções no padrão morfológico de frutos de pimentas do gênero Capsicum spp. (Solanaceae) utilizados por grupos tradicionais indígenas (vivendo em aldeias) e não-indígenas (derivado da migração/colonização, contendo ou não miscigenação, situados fora de áreas indígenas), em Roraima, norte da Amazônia brasileira. Para tanto foi utilizado um banco de dados com 182 subamostras de Capsicum spp. coletadas em 39 localidades daquele estado (14 indígenas e 25 não-indígenas). As localidades foram caracterizadas também por tipos fitofisionômicos predominantes (savana ou floresta) e por zona domiciliar do usuário (rural ou urbana). Os resultados indicaram haver diferenças morfológicas nos frutos de pimenta relacionadas tanto a fitofisionomia, quanto a zona domiciliar da área de coleta, mas não a origem étnica do grupo. Isto indica que as diferenças estão relacionadas mais a fatores inerentes aos tratos culturais, fortemente influenciados pelo ambiente, que à preferência do usuário. Os morfotipos com frutos de menor peso e alta pungêngia das espécies C. chinense e C. frutescens, independente da cor, foram os preferidos dos usuários indígenas e não-indígenas para produção de molhos e jiquitaia (pó de pimenta). A 'aderência cultural' é sugerida para explicar o uso preferencial comum de pimentas entre os agrupamentos étnicos analisados em Roraima

A podridão do tronco do sisal

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On the use of haptic tablets for UGV teleoperation in unstructured environments: system design and evaluation

Teleoperation of Unmanned Ground Vehicles (UGVs), particularly for inspection of unstructured and unfamiliar environments still raises important challenges from the point of view of the operator interface. One of these challenges is caused by the fact that all information available to the operator is presented to the operator through a computer interface, providing only a partial view of the robot situation. The majority of existing interfaces provide information using visual, and, less frequently, sound channels. The lack of Situation Awareness (SA), caused by this partial view, may lead to an incorrect and inefficient response to the current UGV state, usually confusing and frustrating the human operator. For instance, the UGV may become stuck in debris while the operator struggles to move the robot, not understanding the cause of the UGV lack of motion. We address this problem by studying the use of haptic feedback to improve operator SA. More precisely, improving SA with respect to the traction state of the UGV, using a haptic tablet for both commanding the robot and conveying traction state to the user by haptic feedback. We report (1) a teleoperating interface, integrating a haptic tablet with an existing UGV teleoperation interface, and (2) the experimental results of a user study designed to evaluate the advantage of this interface in the teleoperation of a UGV, in a search and rescue scenario. Statistically significant results were found supporting the hypothesis that using the haptic tablet elicits a reduction in the time that the UGV spends in states without traction.info:eu-repo/semantics/publishedVersio

Levantamento detalhado de solos em uma área de reassentamento de colonos na Bacia do Jatobá - PE.

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