6 resultados para vibration active control

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

80.00% 80.00%

Publicador:

Resumo:

The industries of food, medicine and cosmetic apply microencapsulation for many reasons, among them, stabilize the active, control the release of encapsulated and separate incompatible components of the formulation. In this context, microencapsulation techniques have been used in the food industry to provide stable liquid and solid ingredients. Anthocyanins have high antioxidant potential, but they are photodegradable. The challenges are therefore directed to the research for techniques that could make this potential remaining active and bioavailable and could be used as a vehicle for the delivery release of bioactive and micronutrients in appropriate conditions and levels. This work has as main objective to propose a method to encapsulate the anthocyanins in the extract of mountain apple using the interfacial polymerization technique. As well as to define the ideal conditions of temperature and agitation system for this procedure. The microparticles were characterized for size, morphology, active distribution, surface charge, degradation, composition and stability. The results, like particle diameter of 5.94 μm and Zeta potential of 7.03 mV, showed that the technique used to obtain these microparticles was satisfactory and has potential for application in cosmetics and food

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Background: stroke causes long-term impairments, limitation of activities and restriction in participation in daily life situations, especially for upper limb impairment (UL). Action Observation (AO) has been used for the rehabilitation of UL in these patients. It's a multisensory therapy which consists in observing a healthy subject performing a motor task, followed by physical practice. Objectives: assess whether the AO improves motor function of UL and dependence for activities of daily living (ADLs) of stroke patients or cause any adverse effects. Search methods: a search strategy was words and terms used for the identification of articles, in the following scientific basis Cochrane Central Register of Controlled Trials; MEDLINE; PsycINFO; CINAHL and LILACS. In addition to manual search of the references of articles and search for theses and dissertations in Portal Capes and LILACS. The identification of the studies was conducted from October to December 2015, being the last search on December 3. Selection criteria: randomised controlled trials (RCT) involving adults with stroke who had deficits in upper limb function and used AO as an intervention. Data collection and analysis: the data extracted from the studies were used to analyze the risk of bias, the effect of the treatment and the quality of the body of evidence. Main results: 6 studies were included, totaling 270 patients. The primary outcome analyzed was the motor function of MS. Were combined in meta-analyzes studies comparing AO versus placebo or an active control, considering the immediate and long-term effect (n=241). Regarding the motor function of the arm (5 trials), the estimated effect for the therapy was not significant. However, when considering the hand function estimating the effect was favorable to the group that conducted the AO, in short (mean difference = 6.93, 95% CI 1.48 to 12.39; P = 0.01) and long-term (mean difference = 7.57; 95% CI 1.34 the 13.80; p = 0.02). Unable to perform the analysis for functional dependency. The studies showed a low or uncertain risk of bias, but the quality of evidence the body was considered low and very low quality. Authors’ conclusions: AO was effective in improving hand function of stroke patients. Despite the low quality evidence that the use of OA in clinical practice should not be discouraged. RCT new studies should be conducted with greater methodological rigor and larger samples, covering important outcomes such as functional dependence for ADLs.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

ARAUJO, Márcio V. ; ALSINA, Pablo J. ; MEDEIROS, Adelardo A. D. ; PEREIRA, Jonathan P.P. ; DOMINGOS, Elber C. ; ARAÚJO, Fábio M.U. ; SILVA, Jáder S. . Development of an Active Orthosis Prototype for Lower Limbs. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 20., 2009, Gramado, RS. Proceedings… Gramado, RS: [s. n.], 2009

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Smart structures and systems have the main purpose to mimic living organisms, which are essentially characterized by an autoregulatory behavior. Therefore, this kind of structure has adaptive characteristics with stimulus-response mechanisms. The term adaptive structure has been used to identify structural systems that are capable of changing their geometry or physical properties with the purpose of performing a specific task. In this work, a sliding mode controller with fuzzy inference is applied for active vibration control in an SMA two-bar truss. In order to obtain a simpler controller, a polynomial model is used in the control law, while a more sophisticated version, which presents close agreement with experimental data, is applied to describe the SMA behavior of the structural elements. This system has a rich dynamic response and can easily reach a chaotic behavior even at moderate loads and frequencies. Therefore, this approach has the advantage of not only obtaining a simpler control law, but also allows its robustness be evidenced. Numerical simulations are carried out in order to demonstrate the control system performance.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Smart structures and systems have the main purpose to mimic living organisms, which are essentially characterized by an autoregulatory behavior. Therefore, this kind of structure has adaptive characteristics with stimulus-response mechanisms. The term adaptive structure has been used to identify structural systems that are capable of changing their geometry or physical properties with the purpose of performing a specific task. In this work, a sliding mode controller with fuzzy inference is applied for active vibration control in an SMA two-bar truss. In order to obtain a simpler controller, a polynomial model is used in the control law, while a more sophisticated version, which presents close agreement with experimental data, is applied to describe the SMA behavior of the structural elements. This system has a rich dynamic response and can easily reach a chaotic behavior even at moderate loads and frequencies. Therefore, this approach has the advantage of not only obtaining a simpler control law, but also allows its robustness be evidenced. Numerical simulations are carried out in order to demonstrate the control system performance.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

ARAUJO, Márcio V. ; ALSINA, Pablo J. ; MEDEIROS, Adelardo A. D. ; PEREIRA, Jonathan P.P. ; DOMINGOS, Elber C. ; ARAÚJO, Fábio M.U. ; SILVA, Jáder S. . Development of an Active Orthosis Prototype for Lower Limbs. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 20., 2009, Gramado, RS. Proceedings… Gramado, RS: [s. n.], 2009