Search results for "DEMAND"
showing 10 items of 759 documents
Exploring the limits of anaerobic biodegradability of urban wastewater by AnMBR technology
2018
[EN] Anaerobic membrane bioreactors (AnMBRs) can achieve maximum energy recovery from urban wastewater (UWW) by converting influent COD into methane. The aim of this study was to assess the anaerobic biodegradability limits of urban wastewater with AnMBR technology by studying the possible degradation of the organic matter considered as non-biodegradable as observed in aerobic membrane bioreactors operated at very high sludge retention times. For this, the results obtained in an AnMBR pilot plant operated at very high SRT (140 days) treating sulfate-rich urban wastewater were compared with those previously obtained with the system operating at lower SRT (29 to 70 days). At 140 days SRT the …
Wastewater COD characterization: analysis of respirometric and physical-chemical methods for determining biodegradable organic matter fractions
2010
BACKGROUND: In this work, a comprehensive study of the respirometric and physical–chemical methods has been performed to evaluate the information provided by these two methodologies in order to assess the biodegradable organic matter fractions of wastewater. RESULTS: First, an analysis was performed of the influence of the initial substrate on biomass ratio (F0/X0) in the assessment of readily biodegradable organic matter, SS, through respirometric experiments. In order to achieve an adequate assessment of the SS component, similar conditions (given by the initial F0/X0 ratio) must be employed in experiments that are carried to determine SS and YH (heterotrophic yield). Second, a comparativ…
Ionic Liquids on Demand in Continuous Flow
2009
We report on the development of an alternative protocol for the facile, solvent-free synthesis of various novel imidazolium-based ionic liquids (ILs) that affords highly pure products without the necessity of subsequent purification steps. The continuous approach is based on the combination of HPLC pumps with a micromixer and a capillary residence tube. Our system provides a high degree of control over the alkylation reactions due to a high surface-to-volume ratio and superior heat and mass transport. Within the scope of our studies, we focused on ionic liquids containing differently substituted phenyl rings and characterized these compounds with respect to further use for direct applicatio…
Influence of Reactant Polarity on the Course of the Inverse-Electron-Demand Diels−Alder Reaction. A DFT Study of Regio- and Stereoselectivity, Presen…
1999
The molecular mechanisms for the inverse-electron-demand Diels−Alder reactions between nitroethene and three substituted ethenes (propene, methyl vinyl ether, and dimethylvinylamine) to give the corresponding nitroso cycloadducts have been characterized with density functional theory methods using the B3LYP/6-31G* calculational level. On the basis of stability arguments and molecular orbital analysis relative rates, regioselectivity, and stereoselectivity, the presence of Lewis acid catalyst modeled by the BH3 system and the inclusion of solvent effects as a function of the nature of substituent in the dienophile fragment are analyzed and discussed. The ortho attack mode presents transition…
ChemInform Abstract: Influence of Reactant Polarity on the Course of the Inverse-Electron-Demand Diels-Alder Reaction. A DFT Study of Regio- and Ster…
2010
The molecular mechanisms for the inverse-electron-demand Diels−Alder reactions between nitroethene and three substituted ethenes (propene, methyl vinyl ether, and dimethylvinylamine) to give the corresponding nitroso cycloadducts have been characterized with density functional theory methods using the B3LYP/6-31G* calculational level. On the basis of stability arguments and molecular orbital analysis relative rates, regioselectivity, and stereoselectivity, the presence of Lewis acid catalyst modeled by the BH3 system and the inclusion of solvent effects as a function of the nature of substituent in the dienophile fragment are analyzed and discussed. The ortho attack mode presents transition…
Networked Analysis of a Teaching Unit for Primary School Symmetries in the Form of an E-Book
2021
In mathematics education, technology offers many opportunities to enrich curricular contents. Plane symmetries is a topic often skipped by primary teachers. However, it is important and may be worked in attractive ways in dynamic geometry software environments. In any regular classroom there are students with different levels of mathematical attainment, some needing easy tasks while others, particularly mathematically-gifted students, need challenging problems. We present a teaching unit for plane symmetries, adequate for upper primary school grades, implemented in a fully interactive electronic book, with most activities solved in GeoGebra apps. The book allows student to choose which itin…
Studies on money and labour market dynamics and goods market imperfections
2010
Rinse, Repeat. Paratextual Poetics of Literary Twitter Collage Retweeted
2019
This essay studies what happens to the poetics of a text that was first written on or for a certain internet platform when it is later copy-pasted to a different literary medium – that of an edited and printed book. The main target of the discussion is Finnish author Karri Kokko’s conceptual literary work Retweeted (2016), a print-on-demand book, the roots of which are firmly in both the traditions of print media and the digital interfaces of the social media platform Twitter. The analysis pays close attention to the medial qualities of both Twitter and the conceptual novel that draws material from it. The essay aims to highlight the poetic qualities of the material produced and circulated …
The on-demand warehousing problem
2022
Warehouses are key elements of supply chain networks, and great attention is paid to increase their efficiency. Highly volatile space requirements are enablers of innovative resource sharing concepts, where warehouse capacities are traded on online platforms. In this context, our paper introduces the on-demand warehousing problem from the perspective of platform providers. The objective prioritises demand–supply matching with maximisation of the number of transactions. If there is a tie, the secondary objective maximises the number of suppliers matched with at least one customer and the number of customers that have matches within a specific threshold with respect to the minimum achievable …
Intensified Job Demands and Cognitive Stress Symptoms : The Moderator Role of Individual Characteristics
2020
Intensified job demands (IJDs) originate in the general accelerated pace of society and ever-changing working conditions, which subject workers to increasing workloads and deadlines, constant planning and decision-making about one’s job and career, and the continual learning of new professional knowledge and skills. This study investigated how individual characteristics, namely negative and positive affectivity related to competence demands, and multitasking preference moderate the association between IJDs and cognitive stress symptoms among media workers (n = 833; 69% female, mean age 48 years). The results show that although IJDs were associated with higher cognitive stress symptoms at wo…