1,142 research outputs found
Magnetic suspension characteristics of electromagnetic actuators
Electromagnetic actuators that use a current-carrying coil (which is placed in a magnetic field) to generate mechanical force are conceptually attractive components for active control of rotating shafts. In one concept that is being tested in the laboratory, the control forces from such actuators are applied on the flexibly supported bearing housings of the rotor. Development of this concept into a practical reality requires a clear and thorough understanding of the role of electromechanical parameters of these actuators in delivering the right amount of control force at the right phase into the rotor. The electromechanical parameters of the actuators investigated are the mass of the armature, stiffness of its suspension, electrical resistance, and inductance of the coils. Improper selection of these parameters can result in degradation in their performance, leading to mistuning between the actuator and the rotor. Through a simple analysis, it is shown that use of such mistuned actuators could result in sharp fluctuations in the phase of the control force delivered into the rotor around the critical speeds. These sharp fluctuations in phase, called 'Phase Glitches', are undesirable. Hence, future designs of controllers should take into account the undesirable mistuning effects between the actuator and the rotor caused by the phase glitches
Computer-based attention-demanding testing unveils severe neglect in apparently intact patients
We tested a group of ten post-acute right-hemisphere damaged patients. Patients had no neglect according to paper-and-pencil cancellation tasks. They were administered computer-based single- and dual-tasks, requiring to orally name the position of appearance (e.g. left vs. right) of briefly-presented lateralized targets. Patients omitted a consistent number of contralesional targets (approximate to 40%) under the single-task condition. When required to perform a concurrent task which recruited additional attentional resources (dual-tasks), patients' awareness for contralesional hemispace was severely affected, with less than one third of contralesional targets detected (approximate to 70% of omissions). In contrast, performance for ipsilesional (right-sided) targets was close to ceiling, showing that the deficit unveiled by computer-based testing selectively affected the contralesional hemispace. We conclude that computer-based, attention-demanding tasks are strikingly more sensitive than cancellation tasks in detecting neglect, because they are relatively immune to compensatory strategies that are often deployed by post-acute patients
Non-compliance with colonoscopy after a positive faecal immunochemical test doubles the risk of dying from colorectal cancer.
The risk of colorectal cancer (CRC) among subjects with a positive faecal immunochemical test (FIT) who do not undergo a colonoscopy is unknown. We estimated whether non-compliance with colonoscopy after a positive FIT is associated with increased CRC incidence and mortality.
The FIT-based CRC screening programme in the Veneto region (Italy) invited persons aged 50 to 69 years with a positive FIT (>20 µg Hb/g faeces) for diagnostic colonoscopy at an endoscopic referral centre. In this retrospective cohort study, we compared the 10-year cumulative CRC incidence and mortality among FIT positives who completed a diagnostic colonoscopy within the programme (compliers) and those who did not (non-compliers), using the Kaplan-Meier estimator and Cox-Aalen models.
Some 88 013 patients who were FIT positive complied with colonoscopy (males: 56.1%; aged 50-59 years: 49.1%) while 23 410 did not (males: 54.6%; aged 50-59 years: 44.9%).The 10-year cumulative incidence of CRC was 44.7 per 1000 (95% CI, 43.1 to 46.3) among colonoscopy compliers and 54.3 per 1000 (95% CI, 49.9 to 58.7) in non-compliers, while the cumulative mortality for CRC was 6.8 per 1000 (95% CI, 5.9 to 7.6) and 16.0 per 1000 (95% CI, 13.1 to 18.9), respectively. The risk of dying of CRC among non-compliers was 103% higher than among compliers (adjusted HR, 2.03; 95% CI, 1.68 to 2.44).
The excess risk of CRC death among those not completing colonoscopy after a positive faecal occult blood test should prompt screening programmes to adopt effective interventions to increase compliance in this high-risk population
Hand–foot motor priming in the presence of temporary inability to use hands
To verify if the link between observed hand actions and executed foot actions found in aplasics is essentially induced by the constant use of foot substituting the hand, we investigated if the vision of a grasping hand is able to prime a foot response in normals. Participants were required to detect the time-to-contact of a hand grasping an object either with a suitable or a less suitable movement, an experimental paradigm known to induce a priming effect. Participants responded either with the hand or the foot, while having free or bound hands. Results showed that for hand responses motor priming effect was stronger when the hands were free, whereas for foot responses it was stronger when the hands were bound. These data are interpreted as a further evidence that a difficulty to move affects specific cognitive functions and that the vision of a grasping hand may prime a foot response
Experimental investigation of drying of malt bagasse
[EN] The aim of this work was to investigate the convective drying process of malt bagasse and to evaluate the influence of this process on the application of this residue as adsorbent in methylene blue removel by adsorption process. The experimental system for drying was a fixed bed dryer with parallel airflow, with operating conditions: air temperature in the range of 40 to 90 oC and air veocity of 2 m/s. The adsorption experiments were perfomed with solution of methylene blue at 70 ppm concentration. The drying kinetics showed a constant drying rate period followed by a falling drying rate. The results obtained for the dye removal efficiency were 56% for in natura sample and in the range of 81.69% to 93.99% for dried samples.Zorzi, B.; Machry, K.; Krolow, P.; Moura, C.; Oliveira, E.; Rosa, G. (2018). Experimental investigation of drying of malt bagasse. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1029-1034. https://doi.org/10.4995/IDS2018.2018.7785OCS1029103
Níveis de metano e perdas energéticas em bovinos de corte, suplementados ou não, em pastagem de capim mombaça (Panicum maximum cv. Mombaça).
Objetivou-se avaliar o impacto da suplementação protéico-energética na emissão de metano (CH4) de novilhos, durante a recria, em pastagem de capim-mombaça. Os tratamentos avaliados foram: T0 - Apenas suplementação mineral; T1 - Suplementação protéico-energética. Utilizou-se a técnica do gás traçador interno hexafluoreto de enxofre (SF6) para estimar a emissão diária de CH4. Foram utilizados 20 animais, sendo dez de cada tratamento, em dois ensaios, com medição de CH4 em cinco dias consecutivos. Na análise estatística dos dados de emissão de CH4 , utilizou-se a metodologia de modelos mistos para medidas repetidas do SAS. Os animais foram também avaliados quanto à eficiência de utilização do alimento, utilizando-se como critério o consumo alimentar residual (CAR). Animais suplementados e não suplementados não diferiram (P>0,05) quanto à produção diária de metano e quanto à perda total diária de energia na forma de CH4. Entretanto, quando a perda de energia foi expressa em g/kg de matéria seca consumida (21,51 vs. 29,76 g/kg) e como porcentagem da energia bruta (EB) ingerida (6,36 versus 8,59 %), os animais suplementados tiveram menores perdas (P0,05) quanto aos níveis de emissão de metano (total ou por kg de matéria seca - MS ingerida). Assim, conclui-se que: a suplementação com concentrado age de forma efetiva na mitigação da emissão de metano; diferenças no CAR não podem ser atribuídas a diferenças nos níveis de emissão de metano
Níveis de metano e perdas energéticas em bovinos de corte, suplementados ou não, em pastagem de capim mombaça (Panicum maximum cv. Mombaça).
Objetivou-se avaliar o impacto da suplementação protéico-energética na emissão de metano (CH4) de novilhos, durante a recria, em pastagem de capim-mombaça. Os tratamentos avaliados foram: T0 ? Apenas suplementação mineral; T1 ? Suplementação protéico-energética. Utilizou-se a técnica do gás traçador interno hexafluoreto de enxofre (SF6) para estimar a emissão diária de CH4. Foram utilizados 20 animais, sendo dez de cada tratamento, em dois ensaios, com medição de CH4 em cinco dias consecutivos. Na análise estatística dos dados de emissão de CH4 , utilizou-se a metodologia de modelos mistos para medidas repetidas do SAS. Os animais foram também avaliados quanto à eficiência de utilização do alimento, utilizando-se como critério o consumo alimentar residual (CAR). Animais suplementados e não suplementados não diferiram (P>0,05) quanto à produção diária de metano e quanto à perda total diária de energia na forma de CH4. Entretanto, quando a perda de energia foi expressa em g/kg de matéria seca consumida (21,51 vs. 29,76 g/kg) e como porcentagem da energia bruta (EB) ingerida (6,36 versus 8,59 %), os animais suplementados tiveram menores perdas (P0,05) quanto aos níveis de emissão de metano (total ou por kg de matéria seca ? MS ingerida). Assim, conclui-se que: a suplementação com concentrado age de forma efetiva na mitigação da emissão de metano; diferenças no CAR não podem ser atribuídas a diferenças nos níveis de emissão de metano
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