230 research outputs found

    Inactivation of Fecal coliforms during solar and photocatalytic disinfection by zinc oxide (ZnO) nanoparticles in compound parabolic concentrators (CPCs)

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    Water samples of 0, 50, and 100 nephelometric turbidity units (NTU) spiked with fecal coliforms (107 CFU/ml) were exposed to natural sunshine in 1l quartz glass tubes fitted with rectors' compound parabolic concentrators CPCS at two forms CPC1 (whit nanoparticle zinc oxide) and CPC2(without nanoparticle zinc oxide). The samples were characterized using the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). On clear days, the complete inactivation times (more than 7-log unit reduction in bacterial population) in the systems with CPC1, and CPC2 were 15, and 30 min, respectively. The maximum temperatures obtained in the water samples were 80°C for CPC1, and 82°C for CPC2. The use of CPC1 with hydroxyl radicals (OH·) production significantly improved the efficiency of the old CPCS technique, since these systems (CPC1-2) shortened the exposure times to solar radiation and also minimized the negative effects of turbidity and also regrowth was zero in the disinfected samples. Due to two simultaneous effects of high temperatures and UV, regrowth in most ways of solar disinfection was not seen in these examples. Overall, this technology has been proved to be a good enhancement method to inactivate microorganisms under real conditions and represents a good alternative technique to drinking water treatment. © 2019, Islamic Azad University

    Robust Output Regulation: Optimization-Based Synthesis and Event-Triggered Implementation

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    We investigate the problem of practical output regulation: Design a controller that brings the system output in the vicinity of a desired target value while keeping the other variables bounded. We consider uncertain systems that are possibly nonlinear and the uncertainty of the linear part is modeled element-wise through a parametric family of matrix boxes. An optimization-based design procedures is proposed that delivers a continuous-time control and estimates the maximal regulation error. We also analyze an event-triggered emulation of this controller, which can be implemented on a digital platform, along with an explicit estimates of the regulation error

    Nucleate pool boiling heat transfer of binary nano mixtures under atmospheric pressure around a smooth horizontal cylinder

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    Influence of Al2O3 nanoparticles on nucleate pool boiling heat transfer of diluted binary water-glycerol mixtures has been experimentally measured up to heat flux 91 kW/m2 at diluted volume fractions of 1% to 5% of glycerol into pure water at volumetric concentrations 0.5%, 1% and 1.5% of Al2O3 nanoparticles. Obtained results indicate that presence of nanoparticles into the mixtures result in increasing the pool boiling heat transfer coefficient values and also result in decreasing the wall superheat temperature of surface. Increased values of heat transfer are increased with increasing the volume fractions of Al2O3 too. Generally, it is concurred that Al2O3 nanoparticles typically enhance the pool boiling heat transfer coefficient of binary water-glycerol mixture in comparison with absence of nanoparticles circumstances, up to 25% at 1.5% Al2O3. Additionally, new simple semi - mathematical model has been proposed for a rough estimating of enhanced values with uncertainty about 8%

    Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition

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    Negated bio-events: Analysis and identification

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    Background: Negation occurs frequently in scientific literature, especially in biomedical literature. It has previously been reported that around 13% of sentences found in biomedical research articles contain negation. Historically, the main motivation for identifying negated events has been to ensure their exclusion from lists of extracted interactions. However, recently, there has been a growing interest in negative results, which has resulted in negation detection being identified as a key challenge in biomedical relation extraction. In this article, we focus on the problem of identifying negated bio-events, given gold standard event annotations.Results: We have conducted a detailed analysis of three open access bio-event corpora containing negation information (i.e., GENIA Event, BioInfer and BioNLP'09 ST), and have identified the main types of negated bio-events. We have analysed the key aspects of a machine learning solution to the problem of detecting negated events, including selection of negation cues, feature engineering and the choice of learning algorithm. Combining the best solutions for each aspect of the problem, we propose a novel framework for the identification of negated bio-events. We have evaluated our system on each of the three open access corpora mentioned above. The performance of the system significantly surpasses the best results previously reported on the BioNLP'09 ST corpus, and achieves even better results on the GENIA Event and BioInfer corpora, both of which contain more varied and complex events.Conclusions: Recently, in the field of biomedical text mining, the development and enhancement of event-based systems has received significant interest. The ability to identify negated events is a key performance element for these systems. We have conducted the first detailed study on the analysis and identification of negated bio-events. Our proposed framework can be integrated with state-of-the-art event extraction systems. The resulting systems will be able to extract bio-events with attached polarities from textual documents, which can serve as the foundation for more elaborate systems that are able to detect mutually contradicting bio-events. © 2013 Nawaz et al.; licensee BioMed Central Ltd

    Thermal Performance and Viscosity of Biologically Produced Silver/Coconut Oil Nanofluids

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    In this work, thermal conductivity, viscosity, and boiling heat transfer coefficient of a biologically produced nano-coolant were experimentally quantified. The nanoparticles were produced from silver nitrate via the plant extraction method and by means of green tea leaf extract. The mean size of the particles was 50 nm, with spherical morphology and single-phase structure of Ag (silver). The synthesized particles were dispersed in coconut oil as base fluid. Thermal conductivity and viscosity of the nanofluid were experimentally measured and correlated based on temperature and concentration of nanoparticles via the regression analysis. Thermal performance of the nanofluid inside an annular heat exchanger with convective boiling conditions (in forced convection and nucleate boiling heat transfer regimes) was assessed. The results demonstrated a superior thermal performance in both heat transfer regions over the base oil, and revealed that this nanofluid can be used as a coolant as well as a lubricant in engines with high heat flux conditions, as its thermal conductivity and viscosity were enhanced due to the presence of Ag particles inside the oil

    Evaluation of labor indices in prolonged pregnancy in Shabihkhani Hospital, Kashan 2003

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    Background: Prolonged pregnancy influences different aspects of maternal and neonatal health. Although it is accepted that drug intervention is necessary before labor in prolonged pregnancy but there is debate about the termination time of the pregnancy. Considering the importance and prevalence of this entity we studied the labor indices in the hospitalized women with prolonged pregnancy in Kashan, in 1382-1383.Material and Methods: This descriptive study carried out on 450 women with gestational age of more than 40 weeks (based on their LMP or sonography before 30 weeks) admitted for termination of pregnancy by induction. They had no medical or obstetrical problem. Labor indices including dilatation and effacement at the time of admission, number of inductions, duration of hospitalization, dystocia and type of delivery, as well as mother�s age, history of prolonged pregnancy, and number of parturitions were recorded and then on the base of gestational age categorized in 4 following groups: 40w to 41w and 3days, 40w and 4days to 41w, 41w and 1days to 41w and 3days and 41w, 4days or more.Results: Data showed that 131 women (29.1) have terminated in 40 to 40w and 3days of gestation and 130 women (28.9) in 40w and 4days to 41w, 150 women (33.3) in 41w and 1days to 41w and 3days and only 39 women (8.7) after 41w and 3 day 12 (2.7) of which were more than 42 weeks. There wasn't significant difference between women in dilatation and effacement on admission, dystocia and type of delivery but there was significant difference in the number of induction and duration of hospitalization. Termination of pregnancy in lower gestational age causes increased number of inductions and duration of hospitalization. The most frequent reason for cesarean section was lack of response to drug interventions and induction in lower gestational age. Conclusion: We recommend no intervention for termination of delayed pregnancy up to 41.5 weeks in women without problem
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