976,191 research outputs found

    Valve degradation detector

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    To determine corrosive degradation of valve while it is in service, detect changes in surface roughness or presence of corrosive layers at junction of poppet and seat by measuring temperature gradients created across junction by small heat source

    Oxidative degradation of a novel AMP/AEP blend designed for CO2 capture based on partial oxy-combustion technology

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    VersiĆ³n aceptada. Embargo 24 mesesSolvent degradation and volatile compound emissions are two of the major concerns about the deployment of carbon capture technologies based on chemical absorption. In this context, partial oxy-combustion might reduce the solvent degradation due to the use of a higher CO2 concentrated flue gas. This work evaluates the oxidative degradation of a novel AMP/AEP blend, namely POS #1, under partial oxy-combustion conditions. The effects of temperature and flue gas composition were evaluated in terms of solvent loss, degradation rates, NH3 emissions and degradation products. The experiments were set at temperatures up to 70ā€ÆĀ°C and two levels of O2 concentration ā€“ 3%v/v and 6%v/v. The CO2 concentration of the flue gas ranged between 15%v/v and 60%v/v CO2. The novel solvent POS#1 showed high resistance to degrade and resulted in lower degradation rates than MEA in all the operating conditions evaluated in this work. The maximum degradation of AEP and AMP was 24% and 19%, respectively. MEA degraded almost double under the same conditions. Temperature and O2 concentration enhanced the oxidative degradation of POS #1. However, the use of higher CO2 concentration in the flue gas led to lower degradation rates of AEP and AMP and hence oxidative degradation was partially inhibited under partial oxy-combustion conditions. The presence of higher CO2 content in the flue gas decreased the NH3 production and a 70% reduction of its emissions was achieved as the CO2 concentration shifted from 15%v/v to 60%v/v. Other major degradation compounds such as formate and 2,4-lutidine were also decreased. New degradation products were not identified so that the suggested degradation pathways proposed in the literature were not influenced by the presence of higher CO2 concentrations.Ministerio de Economia y Competitividad CTM-2014-58573-RUniĆ³n Europea, European Development Research Fund (EDRF

    Effect of pH on ciprofloxacin ozonation in hospital WWTP effluent

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    A bubble column was used for ozonation of the quinolone antibiotic ciprofloxacin and the effect of pH was tested. Degradation at pH 7 increased the ciprofloxacin half life time to 29.1 min compared to pH 3 (26.8 min) and pH 10 (18.7 min), possibly due to increased sorption at neutral pH. Degradation product identification revealed strongest degradation at the piperazinyl substituent at pH 10 while degradation at the quinolone moiety seems promising at pH 7. For P. fluorescens and E. coli, reduction in antibacterial activity, monitored by agar diffusion tests, was in correlation with the ciprofloxacin degradation rate. For B. coagulans, however, no differences in residual antibacterial activity were found in function of pH, indicating that degradation products also affect antibacterial activity of ozonated samples

    The Audio Degradation Toolbox and its Application to Robustness Evaluation

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    We introduce the Audio Degradation Toolbox (ADT) for the controlled degradation of audio signals, and propose its usage as a means of evaluating and comparing the robustness of audio processing algorithms. Music recordings encountered in practical applications are subject to varied, sometimes unpredictable degradation. For example, audio is degraded by low-quality microphones, noisy recording environments, MP3 compression, dynamic compression in broadcasting or vinyl decay. In spite of this, no standard software for the degradation of audio exists, and music processing methods are usually evaluated against clean data. The ADT fills this gap by providing Matlab scripts that emulate a wide range of degradation types. We describe 14 degradation units, and how they can be chained to create more complex, `real-world' degradations. The ADT also provides functionality to adjust existing ground-truth, correcting for temporal distortions introduced by degradation. Using four different music informatics tasks, we show that performance strongly depends on the combination of method and degradation applied. We demonstrate that specific degradations can reduce or even reverse the performance difference between two competing methods. ADT source code, sounds, impulse responses and definitions are freely available for download

    Broad activation of the ubiquitin-proteasome system by Parkin is critical for mitophagy

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    Parkin, an E3 ubiquitin ligase implicated in Parkinson's disease, promotes degradation of dysfunctional mitochondria by autophagy. Using proteomic and cellular approaches, we show that upon translocation to mitochondria, Parkin activates the ubiquitinā€“proteasome system (UPS) for widespread degradation of outer membrane proteins. This is evidenced by an increase in K48-linked polyubiquitin on mitochondria, recruitment of the 26S proteasome and rapid degradation of multiple outer membrane proteins. The degradation of proteins by the UPS occurs independently of the autophagy pathway, and inhibition of the 26S proteasome completely abrogates Parkin-mediated mitophagy in HeLa, SH-SY5Y and mouse cells. Although the mitofusins Mfn1 and Mfn2 are rapid degradation targets of Parkin, we find that degradation of additional targets is essential for mitophagy. These results indicate that remodeling of the mitochondrial outer membrane proteome is important for mitophagy, and reveal a causal link between the UPS and autophagy, the major pathways for degradation of intracellular substrates
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