104 research outputs found

    Framework for a space shuttle main engine health monitoring system

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    A framework developed for a health management system (HMS) which is directed at improving the safety of operation of the Space Shuttle Main Engine (SSME) is summarized. An emphasis was placed on near term technology through requirements to use existing SSME instrumentation and to demonstrate the HMS during SSME ground tests within five years. The HMS framework was developed through an analysis of SSME failure modes, fault detection algorithms, sensor technologies, and hardware architectures. A key feature of the HMS framework design is that a clear path from the ground test system to a flight HMS was maintained. Fault detection techniques based on time series, nonlinear regression, and clustering algorithms were developed and demonstrated on data from SSME ground test failures. The fault detection algorithms exhibited 100 percent detection of faults, had an extremely low false alarm rate, and were robust to sensor loss. These algorithms were incorporated into a hierarchical decision making strategy for overall assessment of SSME health. A preliminary design for a hardware architecture capable of supporting real time operation of the HMS functions was developed. Utilizing modular, commercial off-the-shelf components produced a reliable low cost design with the flexibility to incorporate advances in algorithm and sensor technology as they become available

    Density, refractive index, apparent volumes and excess molar volumes of four protic ionic liquids + water at T=298.15 AND 323.15 K

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    Densities and refractive index of binay mixtures of water with four protic ionic liquids, based on ammonium and fatty acids, were measured at 298.15 and 323.15 K, under atmospheric pressure. Apparent and excess molar volumes were obtained by experiments and fitting data to the Redlich-Meyer (RM), Redlich-Kister (RK) and Prigogine-Flory-Patterson (PFP) equations. The molar volume values were high, suggesting strong ion-solvent interaction. The same interaction also became stronger as the temperature increased. Excess volume values were negative, indicating that packing efficiency ability or attractive interactions occurred in mixtures of ionic liquid + water. The errors (AARD) for the properties in excess were in the range of 1.8% to 7.2%. The PFP error for the apparent volume was in the range of 0.34% to 0.06%, lower than the RM error for the same property, which was in the range of 0.70 to 1.55%. The Gladstone-Dale model was applied to correlate the refractive index of the binary mixture with the density from the values of both pure components323671682FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2011/19736-

    Coupling stem water potential and soil water potential on irrigated and not irrigated vines: preliminary results for Vitis vinifera L. cv Teroldego

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    Improving wine quality necessitates precise control over plant water stress, which requires accurate scheduling of irrigation based on the plant's water status and the soil's water availability. The aim of this experiment is to monitor the water status of grapevines and soil in both irrigated and not-irrigated conditions to quantify differences in the plant's physiological response and yield. In addition, novel microtensiometer probes for measuring continuously the Stem Water Potential were tested for efficacy. These probes were coupled with a handcrafted tensiometer to monitor the Soil Water status and at the end of the season all the yield was analyzed to determine the main oenological parameters driving the final quality of the musts. Initial findings indicate that the microtensiometers gave effective estimates of the vines’ water status, revealing rapid plant responses to water inputs and atmospheric changes. Notably for the experiment, soil moisture exceeded field capacity under irrigated vines before irrigation, suggesting potential water loss through deep percolation, and both the irrigated and not-irrigated vines were in water comfort for all the vegetative season without any detriment both in production and quality

    Detection and distribution of European stone fruit yellows (ESFY) in apricot cv. ‘Bergeron’ and epidemiological studies in the province of Trento (Italy)

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    The aim was to investigate the performance of ‘Bergeron’ on ‘Wavit’ in 4 experimental fields, in the province of Trento (Italy), where European stone fruit yellows (ESFY) caused by “Candidatus Phytoplasma prunorum” has been constantly spreading since 2000.This included visual inspections for typical symptoms (early bud-break during dormancy and premature leaf-roll) and a highly sensitive Real time-PCR (Rt-PCR) assay. 25 % of the propagation material was checked with this method and found to be healthy, before planting in 2005.The epidemiology of the disease was also studied by focusing on: the presence of the vector Cacopsylla pruni (Scopoli) on conifers, the detection of “Ca. P. prunorum” in psyllid eggs and the transmission efficiency at different stages. This was done by exposing apricot trees in 2 locations, during 2 periods from January to July, to the overlapping presence in the orchards of the re-immigrants and the new generation of C. pruni. The results obtained demonstrated that ‘Bergeron’ seems to be highly susceptible to ESFY: typical bud-break was rarely observed, but up to 20-30% of the plants showed premature leaf-roll, fruit deformation and dieback. C. pruni was caught only once on Picea abies during winter; “Ca. P. prunorum” was found in 4 egg samples from 2 locations and the preliminary results on the exposed trees confirmed that the re-immigrants could be the most efficient vectors at least on apricot.Keywords: Prunus armeniaca, cultivar ‘Bergeron’, Real time-PCR, “Candidatus Phytoplasma prunorum”,epidemiolog

    Accounting for risk of non linear portfolios: a novel Fourier approach

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    The presence of non linear instruments is responsible for the emergence of non Gaussian features in the price changes distribution of realistic portfolios, even for Normally distributed risk factors. This is especially true for the benchmark Delta Gamma Normal model, which in general exhibits exponentially damped power law tails. We show how the knowledge of the model characteristic function leads to Fourier representations for two standard risk measures, the Value at Risk and the Expected Shortfall, and for their sensitivities with respect to the model parameters. We detail the numerical implementation of our formulae and we emphasizes the reliability and efficiency of our results in comparison with Monte Carlo simulation.Comment: 10 pages, 12 figures. Final version accepted for publication on Eur. Phys. J.

    Design, Synthesis and Discovery of N,N'-Carbazoyl-aryl-urea Inhibitors of Zika NS5 Methyltransferase and Virus Replication

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    The recent outbreaks of Zika virus (ZIKV) infection worldwide make the discovery of novel antivirals against flaviviruses a research priority. This work describes the identification of novel inhibitors of ZIKV through a structure‐based virtual screening approach using the ZIKV NS5‐MTase. A novel series of molecules with a carbazoyl‐aryl‐urea structure has been discovered and a library of analogues has been synthesized. The new compounds inhibit ZIKV MTase with IC50 between 23–48 μM. In addition, carbazoyl‐aryl‐ureas also proved to inhibit ZIKV replication activity at micromolar concentration

    FUS-ALS mutants alter FMRP phase separation equilibrium and impair protein translation

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    FUsed in Sarcoma (FUS) is a multifunctional RNA binding protein (RBP). FUS mutations lead to its cytoplasmic mislocalization and cause the neurodegenerative disease amyotrophic lateral sclerosis (ALS). Here, we use mouse and human models with endogenous ALS-associated mutations to study the early consequences of increased cytoplasmic FUS. We show that in axons, mutant FUS condensates sequester and promote the phase separation of fragile X mental retardation protein (FMRP), another RBP associated with neurodegeneration. This leads to repression of translation in mouse and human FUS-ALS motor neurons and is corroborated in vitro, where FUS and FMRP copartition and repress translation. Last, we show that translation of FMRP-bound RNAs is reduced in vivo in FUS-ALS motor neurons. Our results unravel new pathomechanisms of FUS-ALS and identify a novel paradigm by which mutations in one RBP favor the formation of condensates sequestering other RBPs, affecting crucial biological functions, such as protein translation

    DESTILAÇÃO DE ÁGUA POR ENERGIA SOLAR

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    Vários países têm enfrentado problemas relacionados ao fornecimento de água potável e também para atender às necessidades das indústrias. Alguns destes países têm procurado soluções para obter água purificada a partir de água salgada encontrada em poços ou água do mar. O objetivo deste trabalho foi realizar um estudo sobre produtos processos tecnológicos na área de purificação de água por energia solar abrangendo documentos de patentes publicados desde a década de 1950. A China destaca-se no número de patentes e inventores. Grande parte dos processos de purificação são fundamentalmente baseados na vaporização de água através da concentração de energia solar por espelhos côncavos ou por placas metálicas com estruturas tipo estufa. O Brasil tem sete depósitos de patentes nesta área, disponíveis nas bases de dados nacionais e internacionais
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