University of the Aegean

About: University of the Aegean is a education organization based out in Mytilene, Greece. It is known for research contribution in the topics: Population & Context (language use). The organization has 2818 authors who have published 8100 publications receiving 179275 citations. The organization is also known as: UAEG.

DBP levels in chlorinated drinking water: effect of humic substances.

Abstract: Chlorination is the most widely used technique for disinfection of drinking water A consequence of chlorination is the formation of Disinfection By-Products (DBPs) The formation of DBPs in drinking water results from the reaction of chlorine with naturally occurring organic materials, principally humic and fulvic acids This paper focuses on the effect of humic substances on the formation of twenty-four compounds belonging to different categories of DBPs This investigation was conducted in two water treatment plants in Greece, Menidi and Galatsi, from July 1999 to April 2000 Humic substances were determined by the diethylaminoethyl (DEAE) method with subsequent UV measurement The techniques used for the determination of DBPs were liquid-liquid extraction, gas chromatography and mass spectrometry The concentrations of DBPs were generally low Total trihalomethanes (TTHMs) ranged from 51 to 246 microg L(-1), and total haloacetic acids (HAAs) concentration ranged from 86 to 284 microg L(-1), while haloaketones (HKs) and chloral hydrate (CH) occurred below 1 microg L(-1) The content of humic substances was found to influence the formation of DBPs and especially TTHMs, trichloroacetic acid (TCA), dibromoacetic acid (DBA), CH, 1,1-dichloropropanone (11-DCP) and 1,1,1-trichloropropanone (1,1,1-TCP) Seasonal variation of TTHMs and HAAs generally followed that of humic substances content with peaks occurring in autumn and spring The trends of 1,1-DCP, 1,1,1-TCP and CH formation seemed to be in contrast to TTHMs and HAAs Trends of formation of individual compounds varied in some cases, probably due to influence of parameters other than humic substances content Statistical analysis of the results showed that the concentrations of TTHMs, CH, 1,1-DCP, 1,1,1-TCP, TCA and DBA are strongly affected from humic substances content (at 001 confidence level) The opposite is true for dichloroacetic acid (DCA) concentration Humic substances also vary to a statistically significant degree during different months, as well as the concentrations of TTHMs, CH, 1,1-DCP, 1,1,1-TCP, TCA and DCA The variance of DBA was not statistically significant Regarding the effect of sampling station, humic substances content showed no statistically significant difference between the two raw water sources studied

Prototype business models for Mobility-as-a-Service

Abstract: Mobility as a Service (MaaS) is a promising concept which aims at offering seamless mobility to end users and providing economic, societal, transport-related and environmental benefits to the cities of the future. To achieve a successful future market take-up of MaaS it is important to develop prototype business models to offer high-value bundled mobility services to customers, as well as enable the MaaS operator and the involved actors to capture value. This paper aims at investigating the business perspective of MaaS by collecting qualitative data from workshops and in-depth interviews in three European metropolitan areas: Budapest, Greater Manchester and the city of Luxembourg. The analysis of the collected data contributed to the in-depth analysis of the MaaS business ecosystem and the identification of the champions of MaaS in the three areas. Prototype business models for MaaS are developed based on the Osterwalder’s canvas, to describe how MaaS operators may create, deliver, and capture value. Our findings indicate that the MaaS ecosystem comprises of public and private actors who need to cooperate and compete in order to capture value. Although noticeable deviations among the study areas are observed, mobility service providers, public transport authorities and regional authorities were commonly indicated as the key actors in a MaaS partnership. In addition, viewed as a system, enablers and barriers to MaaS are identified based on the systems’ of innovation approach. The analysis indicates that the regulatory framework of the cities, the lack of standardization and openness of the application programming interfaces and the need for transport-related investments constitute risks for the successful implementation of MaaS in the study areas. Trust between MaaS actors and cooperation in e-ticketing are key enablers in some of the study areas.

Measurements of b-jet tagging efficiency with the ATLAS detector using tt¯ events at √s=13 TeV

Abstract: The efficiency to identify jets containing b-hadrons (b-jets) is measured using a high purity sample of dileptonic top quark-antiquark pairs ( $ t\overline{t} $ ) selected from the 36.1 fb$^{−1}$ of data collected by the ATLAS detector in 2015 and 2016 from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy $ \sqrt{s}=13 $ TeV. Two methods are used to extract the efficiency from $ t\overline{t} $ events, a combinatorial likelihood approach and a tag-and-probe method. A boosted decision tree, not using b-tagging information, is used to select events in which two b-jets are present, which reduces the dominant uncertainty in the modelling of the flavour of the jets. The efficiency is extracted for jets in a transverse momentum range from 20 to 300 GeV, with data-to-simulation scale factors calculated by comparing the efficiency measured using collision data to that predicted by the simulation. The two methods give compatible results, and achieve a similar level of precision, measuring data-to-simulation scale factors close to unity with uncertainties ranging from 2% to 12% depending on the jet transverse momentum.