385 research outputs found
Design and modeling of an integrated flywheel magnetic suspension for kinetic energy storage systems
The paper presents a novel configuration of an axial hybrid magnetic bearing (AHMB) for the suspension of steel flywheels applied in power-intensive energy storage systems. The combination of a permanent magnet (PM) with excited coil enables one to reduce the power consumption, to limit the system volume, and to apply an effective control in the presence of several types of disturbances. The electromagnetic design of the AHMB parts is carried out by parametric finite element analyses with the purpose to optimize the force performances as well as the winding inductance affecting the electrical supply rating and control capability. Such investigation considers both the temperature dependence of the PM properties and the magnetic saturation effects. The electrical parameters and the force characteristics are then implemented in a control scheme, reproducing the electromechanical behavior of the AHMB-flywheel system. The parameter tuning of the controllers is executed by a Matlab/Simulink code, examining the instantaneous profiles of both the air-gap length and the winding ampere-turns. The results of different dynamic tests are presented, evidencing the smooth air-gap changes and the optimized coil utilization, which are desirable features for a safe and efficient flywheel energy storage
Nitrifying soil bacterium Nitrosomonas europaea: operational improvement of standard culture medium
Nitrosomonas europaea is the most extensively studied ammonia-oxidizing bacterium (AOB), being a ubiquitous player in the conversion of ammonia in the soil environment. The precipitation of constituents of the standard culture medium, American Type Culture Collection (ATCC) \#2265, further hinders both the study of N. europaea vital role in the nitrogen cycle and the development of biotechnological applications, as the presence of inorganic debris severely compromises scale-up procedures and downstream processing. The standard formulation was analyzed; the precipitate was identified as being struvite. Struvite is spontaneously formed when magnesium, phosphate, and ammonium are available in a high pH solution. This combination is common and transversal to a series of AOB media formulations. Therefore, a non-precipitating medium was developed. The modified medium does not require filter sterilization, which reduces 99\\% of its production cost. The kinetic performance of N. europaea was evaluated in the standard and modified medium. A precise and direct quantification of the bacterium cell growth profile was achieved using fluorescent in situ hybridization (FISH) and flow cytometry, which was correlated with other metabolic parameters. The performance of N. europaea was not impaired in the modified medium.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Susana Cortez would like to acknowledge the research grant funded by FCT (SFRH/BPD/73720/2010). Gonzalo Tortella would like to acknowledge the FONDECYT project 1161713.info:eu-repo/semantics/publishedVersio
Induction Machine Stator Fault Tracking using the Growing Curvilinear Component Analysis
Detection of stator-based faults in Induction Machines (IMs) can be carried out in numerous ways. In particular, the shorted turns in stator windings of IM are among the most common faults in the industry. As a matter of fact, most IMs come with pre-installed current sensors for the purpose of control and protection. At this aim, using only the stator current for fault detection has become a recent trend nowadays as it is much cheaper than installing additional sensors. The three-phase stator current signatures have been used in this study to observe the effect of stator inter-turn fault with respect to the healthy condition of the IM. The pre-processing of the healthy and faulty current signatures has been done via the in-built DSP module of dSPACE after which, these current signatures are passed into the MATLABÂź software for further analysis using AI techniques. The authors present a Growing Curvilinear Component Analysis (GCCA) neural network that is capable of detecting and follow the evolution of the stator fault using the stator current signature, making online fault detection possible. For this purpose, a topological manifold analysis is carried out to study the fault evolution, which is a fundamental step for calibrating the GCCA neural network. The effectiveness of the proposed method has been verified experimentally
Predictors of nonâadherence to prescribed prophylactic clottingâfactor treatment regimens among adolescent and young adults with a bleeding disorder
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/133588/1/hae12951_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133588/2/hae12951.pd
Fungal pellets of Anthracophyllum discolor with different formulations to improve biological activities in a biomixture under atrazine application
Carbendazim dissipation in the biomixture of on-farm biopurification systems and its effect on microbial communities
The impact of repeated carbendazim (CARB) applications on the extent of \CARB\ dissipation, the microbial diversity, the community level physiological profile (CLPP), and the enzymatic activity within the biomixture of an on-farm biopurification system was evaluated. After three successive \CARB\ applications, the \CARB\ dissipation efficiency was high; the efficiency of dissipation was 87%, 94% and 96% after each application, respectively. Although microbial enzymatic activity was affected significantly by \CARB\ application, it could recover after each \CARB\ pulse. Likewise, the numbers of cultivable bacteria, fungi and actinomycetes (as measured in CFUs) were slightly affected by the addition of CARB, but the inhibitory effect of the pesticide application was temporary. Denaturing gradient gel electrophoresis (DGGE) and Biolog Ecoplate assays demonstrated that the microbial populations remained relatively stable over time when compared to the control. The results obtained herein therefore demonstrate the high dissipation capacity of this biomixture and highlight the microbiological robustness of this biological system.This work was supported by FONDECYT project No 11100236
Combined microbiological test to assess changes in an organic matrix used to avoid agricultural soil contamination, exposed to an insecticide
Combined microbiological test (Biolog Ecoplate, denaturing gradient gel electrophoresis (DGGE) and Real Time PCR (qPCR)) were developed to evaluate the impact of repeated diazinon (DZN) applications at high concentration (40 mg kg-1) on microbial communities in a microcosm simulating the organic matrix (straw (50%): peat (25%): soil (25%) vv-1) of an pesticide biopurification system (PBS). Moreover, pesticide dissipation was also evaluated. After three successive exposition of DZN, dissipation efficiency was high; achieved 87%, 93% and 96% after each application, respectively showing a clear accelerated dissipation of this pesticide in the organic matrix. The results obtained with Biolog Ecoplate showed that community level physiological profiles were no affected by the addition of DZN. On the other hand, molecular assays (DGGE and QPCR) demonstrated that the microbial structure (bacteria and fungi) remained relatively stable over time with high DZN doses compared to control. Therefore, the results of the present study, clearly, demonstrate the high dissipation capacity of this biomixture and highlight the microbiological robustness of this biological system.Fil: Tortella, G. R.. Universidad de la Frontera. Nucleo Cientifico y Tecnologico En Recursos Naturales (bioren-ufro). Departamento de Ciencias Quimicas y Recursos Naturales; ChileFil: Salgado, E.. Universidad de la Frontera. Nucleo Cientifico y TecnolĂłgico En Recursos Naturales; ChileFil: Cuozzo, Sergio Antonio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico TucumĂĄn. Planta Piloto de Procesos Industriales MicrobiolĂłgicos (i); ArgentinaFil: Mella Herrera, R. A.. Universidad de la Frontera. Nucleo Cientifico y TecnolĂłgico En Recursos Naturales; ChileFil: Parra, L.. Universidad de la Frontera. NĂșcleo CientĂfico y TecnolĂłgico en Recursos Naturales; ChileFil: Diez, M. C.. Universidad de la Frontera. Nucleo Cientifico y TecnolĂłgico En Recursos Naturales; ChileFil: Rubilar, O.. Universidad de la Frontera. Nucleo Cientifico y TecnolĂłgico En Recursos Naturales; Chil
Virtual reality versus computer-aided exposure treatments for fear of flying
Evidence is growing that two modalities of computer-based exposure therapiesâvirtual reality and computer-aided psychotherapyâare effective in treating anxiety disorders, including fear of flying. However, they have not yet been directly compared. The aim of this study was to analyze the efficacy of three computer-based exposure treatments for fear of flying: virtual reality exposure therapy (VRET), computer-aided exposure with a therapistâs (CAE-T) assistance throughout exposure sessions, and self-administered computer-aided exposure (CAE-SA). A total of 60 participants with flying phobia were randomly assigned to VRET, CAE-T, or CAE-SA. Results indicate that the three interventions were effective in reducing fear of flying at posttreatment and at 1-year follow-up; furthermore, there were no significant differences between them in any of the outcome measure. Large within-group effect sizes were found for all three treatment conditions at both posttreatment and at follow-up. The results suggest that therapist involvement might be minimized during computer-based treatments and that CAE can be as effective as VRET in reducing fear of flyin
Neuronal and glial markers are differently associated with computed tomography findings and outcome in patients with severe traumatic brain injury: a case control study
NNZ-2566 treatment inhibits neuroinflammation and pro-inflammatory cytokine expression induced by experimental penetrating ballistic-like brain injury in rats
<p>Abstract</p> <p>Background</p> <p>Inflammatory cytokines play a crucial role in the pathophysiology of traumatic brain injury (TBI), exerting either deleterious effects on the progression of tissue damage or beneficial roles during recovery and repair. NNZ-2566, a synthetic analogue of the neuroprotective tripeptide Glypromate<sup>Âź</sup>, has been shown to be neuroprotective in animal models of brain injury. The goal of this study was to determine the effects of NNZ-2566 on inflammatory cytokine expression and neuroinflammation induced by penetrating ballistic-like brain injury (PBBI) in rats.</p> <p>Methods</p> <p>NNZ-2566 or vehicle (saline) was administered intravenously as a bolus injection (10 mg/kg) at 30 min post-injury, immediately followed by a continuous infusion of NNZ-2566 (3 mg/kg/h), or equal volume of vehicle, for various durations. Inflammatory cytokine gene expression from the brain tissue of rats exposed to PBBI was evaluated using microarray, quantitative real time PCR (QRT-PCR), and enzyme-linked immunosorbent assay (ELISA) array. Histopathology of the injured brains was examined using hematoxylin and eosin (H&E) and immunocytochemistry of inflammatory cytokine IL-1ÎČ.</p> <p>Results</p> <p>NNZ-2566 treatment significantly reduced injury-mediated up-regulation of IL-1ÎČ, TNF-α, E-selectin and IL-6 mRNA during the acute injury phase. ELISA cytokine array showed that NZ-2566 treatment significantly reduced levels of the pro-inflammatory cytokines IL-1ÎČ, TNF-α and IFN-Îł in the injured brain, but did not affect anti-inflammatory cytokine IL-6 levels.</p> <p>Conclusion</p> <p>Collectively, these results suggest that the neuroprotective effects of NNZ-2566 may, in part, be functionally attributed to the compound's ability to modulate expression of multiple neuroinflammatory mediators in the injured brain.</p
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