99 research outputs found
Calibration Khafagi venturi QV 303 and QV 308: Discharge characteristics for free flow and submerged flow
No full textExploring the novel PES/malachite mixed matrix membrane to remove organic matter for water purification
No full text© 2020 Institution of Chemical Engineers This study presents a greener approach to fabricate mixed matrix membranes (MMMs) by introducing malachite nanoparticles (MLC NPs) synthesized from copper sulfate, a toxic waste from many industrial applications, into polyethersulfone (PES) membrane to remove organic matter for water reclamation. The PES/MLC MMMs were characterized by XRD, FTIR, SEM(EDX), Raman Spectroscopy, Photoluminescence Spectrometry, and Contact angle measurements. Results showed that the incorporation of MLC NPs into PES altered the membrane morphology, and made the membrane more hydrophilic. At the optimal amount of 0.1 wt.% MLC NPs, PES/MLC showed the best water flux of 931.1 L/(m2 h) (LMH) with the highest breaking stability of 5.06 ± 0.33 MPa. The membrane also exhibited enhanced adsorption of organic foulants with a corresponding flux recovery rate of 0.55 ± 0.03%. The inevitable agglomeration of MLC NPs witnessed at MLC NP dosage of 1 wt.% compromised either the throughput or the mechanical integrity. The elevated NP loading rate from 0 to 1 wt.% enhanced the removal rate of organic carbon (C) from 20.8 ± 1.7% to 26.3 ± 2.3%, respectively. Optical methods demonstrated the preferential rejection of aromatic constituents by the fabricated membranes suggests their potential applicability of optical methods, particularly the fluorescence spectrometry for better prediction of treated water quality by membrane filtration
Organic carbon source-dependent properties of soluble microbial products in sequencing batch reactors and its effects on membrane fouling
No full text© 2019 Elsevier Ltd This study investigated the influence of three different organic carbon sources including sodium acetate (SOD), glucose (GLU), and starch (STAR), on soluble microbial products (SMP), which presumably have dissimilar uptake rates and metabolic pathways, in sequencing batch reactors (SBR) and their subsequent effects on membrane fouling of ultrafiltration (UF). SMP were mainly characterized by fluorescence excitation emission matrix coupled with parallel factor analysis (EEM-PARAFAC) and size exclusion chromatography (SEC). SMP produced in SOD-fed SBR showed higher abundances of protein-like fluorescent component and large sized aliphatic biopolymer (BP) than GLU- or STAR-fed counterpart did, while the STAR-based operation resulted in more SMP enriched with humic-like fluorescence. The differences in SMP exerted marked effects on UF membrane fouling as indicated by the highest fouling potential with reversibility shown for the SMP from the SOD-fed reactor. Regardless of the carbon source, BP fraction and protein-like component exhibited the greatest extent of reversible fouling, suggesting that size exclusion plays a critical role. However, notable differences in the reversible fouling propensity of relatively smaller size fractions among the three SBRs signified the possible involvement of chemical interactions as a secondary fouling mechanism and its dependency on different carbon sources. Our results provide a new insight into the roles of carbon sources in the characteristics of SMP in biological treatment systems and their effects on the post-treatment using membrane filtration, which is ultimately beneficial to the optimization of biological treatment design and membrane filtration operation
Insights into the roles of recently developed coagulants as pretreatment to remove effluent organic matter for membrane fouling mitigation
No full text© 2018 Elsevier B.V. Membrane fouling by dissolved organic matter (EfOM) in secondary treated effluent is a problematic and inevitable issue during wastewater reclamation using low pressure membrane filtration. This study evaluates the performance of coagulation/flocculation (C/F) using two recently developed coagulants (namely TiCl4 and ZrCl4) in comparison to conventional alum (i.e. Al2(SO4)3) as pretreatment to remove EfOM for subsequent ultrafiltration (UF) membrane fouling mitigation. At the optimal dosage, TiCl4-based C/F pretreatment showed the greatest performance in membrane fouling mitigation, followed by ZrCl4 and then alum. The underlying mechanisms were well explained by classical fouling models and the extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) theory, highlighting a dominant role of standard blocking in the fouling potential of the C/F treated EfOM. The interfacial free energy of cohesion and adhesion showed that C/F pretreatment using TiCl4 and ZrCl4 as coagulant can lower the binding affinity between EfOM molecules and between EfOM molecules and membrane surface, ultimately reduce membrane fouling. The results of size exclusion chromatography (SEC) and fluorescence excitation emission matrix- parallel factor analysis (EEM-PARAFAC) also supported the classical fouling mechanisms, providing additional insights into the potential roles of chemical interactions in the preferential removal of certain organic substances by C/F pretreatment and the chemical composition of subsequent membrane foulants. Protein-like components were highly associated with reversible fouling after the C/F, while the reversibility of humic-like substances was enhanced upon C/F pretreatment. After C/F pretreatment, small sized EfOM molecules became the dominant fraction responsible for UF membrane fouling
નવમા ધોરણના ઇતિહાસમાં વિધાર્થીઓને ગાંધીજીની આઝાદીની ચળવળોમાંથી મૂલ્યોનુ શિક્ષણ
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More hidden heavy quarkonium molecules and their discovery decay modes
No full textTo validate the molecular description of the observed Z(b)(10610)/Z(b)(10650) and Z(c)(3900)/Z(c)(4025), it is valuable to investigate their counterparts, denoted as Z(QV)(()'()) in this work, and the corresponding decay modes. In this work, we present an analysis of the Z(QV)(()'()) using flavor symmetry. We also use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate the partial widths for the isospin conserved channels Z(QV)(()'()) -> eta V-Q. The predicted partial widths are of an order of MeV for Z(QV) -> eta V-Q which corresponds to branching ratios of the order 10(-2) similar to 10(-1). For Z(QV)' -> eta V-Q, the partial widths are a few hundreds of keV and the branching ratios are about 10(-3). Future experimental measurements can test our predictions on the partial widths and thus examine the molecule description of heavy quarkoniumlike exotic states.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)[email protected]
Daniele Del Giudice e «la varietà di tutto il resto»
No full textAccording to a quite popular opinion, Daniele Del Giudice was not a very prolific writer. The modest number of his novels is taken into account both by his devotees and critics; however this may become an unfair distinctive element of a much more complex author. For about forty years, Del Giudice showed and produced ‘Culture’ throughout press, conferences, curatorships, with the same essential prose and immaculate style of his novels and short stories. He is the author of a consistent collateral anthology that needs to be placed side by side with his literature in order to establish organicity and continuity between the two. The article displays and comments his journalistic works for the Paese Sera and the Corriere
Improving algal bloom detection using spectroscopic analysis and machine learning: A case study in a large artificial reservoir, South Korea
No full textThe prediction of algal blooms using traditional water quality indicators is expensive, labor-intensive, and timeconsuming, making it challenging to meet the critical requirement of timely monitoring for prompt management. Using optical measures for forecasting algal blooms is a feasible and useful method to overcome these problems. This study explores the potential application of optical measures to enhance algal bloom prediction in terms of prediction accuracy and workload reduction, aided by machine learning (ML) models. Compared to absorptionderived parameters, commonly used fluorescence indices such as the fluorescence index (FI), humification index (HIX), biological index (BIX), and protein-like component improved the prediction accuracy. However, the prediction accuracy was decreased when all optical indices were considered for computation due to increased noise and uncertainty in the models. With the exception of chemical oxygen demand (COD), this study successfully replaced biochemical oxygen demand (BOD), dissolved organic carbon (DOC), and nutrients with selected fluorescence indices, demonstrating relatively analogous performance in either training or testing data, with consistent and good coefficient of determination (R2) values of approximately 0.85 and 0.74, respectively. Among all models considered, ensemble learning models consistently outperformed conventional regression models and artificial neural networks (ANNs). However, there was a trade-off between accuracy and computation efficiency among the ensemble learning models (i.e., Stacking and XGBoost) for algal bloom prediction. Our study offers a glimpse of the potential application of spectroscopic measures to improve accuracy and efficiency in algal bloom prediction, but further work should be carried out in other water bodies to further validate our proposed hypothesis.LSI
Caractéristiques comparatives de 238 malades anorexiques et boulimiques hospitalisés / Comparisons between anorexia nervosa and bulimia nervosa patients: Study of 238 consecutive hospitalized patients
No full textauthor cannot archive publisher's version/PDFInternational audienceL’histoire, le tableau clinique, le contexte psychologique et la qualité de vie de 238 malades adultes souffrant soit d’anorexie mentale (75 restrictives, AMR et 91 anorexiques-boulimiques, AMB), soit de boulimie (76 malades, B) ont été comparés, lors de leur admission à l’hôpital. Les AMB et B avaient eu, par le passé, un IMC plus élevé et des compulsions alimentaires plus fréquentes que les AMR. Elles s’étaient mis au régime hypocalorique plus souvent que les AMR (p 22) touchait 27 % des malades (plus en cas d’AMB et de B que d’AMR, p 30) touchait 52 % des malades. La qualité de vie (QV) était fortement altérée : elle était touchée dans chacune de ses six composantes (physique, psychique, hédonique, TCA, affective, socioprofessionnelle). Chacun des six sous-scores était au moins trois fois plus élevé (QV plus altérée) que celui de sujets témoins (jusqu’à 11 fois)
Un’austera Venezia di fine XVIII secolo
No full textThe poem La Cuccagna by Giuseppe Lazzari was published during the Venetian Revolution of 1797. This paper will provide an edition based on its two extant copies as well as a commentary, whose aim is to contextualize the poem in regards to the historic events after the fall of the Republic of Venice. Inscribed in the long literary tradition of the ‘land of Cockayne’ or ‘feast of Cockayne’, the text exhibits nonetheless a significant deviation from its more traditional expressions. Taking advantage of the cuccagna’s meaning of wealth and freedom, the author praises Napoleon and the revolution, having faith in new social and political circumstances, while at the same time claiming for radical reforms
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