Search results for "dab"
showing 10 items of 1280 documents
Microsimulation-based passenger car equivalents for heavy vehicles driving turbo-roundabouts
2016
Due to its geometric design, turbo-roundabouts impose greatest constraints to the vehicular trajectories; by consequence, one can expect a more unfavourable impact of heavy vehicles on the traffic conditions than on other types of roundabouts. The present paper addresses the question of how to estimate Passenger Car Equivalents (PCEs) for heavy vehicles driving turbo-roundabouts. The microsimulation approach used revealed as a useful tool for evaluating the variation of quality of traffic in presence of mixed fleets (different percentages of heavy vehicles). Based on the output of multiple runs of several scenarios simulation, capacity functions for each entry lane of the turbo-roundabout w…
Processing and Properties of Biopolymer/Polyhydroxyalkanoates Blends
2011
In this paper, the processability and the performance of a biodegradable polymer, Mater-Bi, and of its blends with either a sample of poly (hydroxy alkanoates) (PHA) or with bacterial biomass containing PHAs were compared. Adding PHA or directly the biomass containing it allows improving the processability of the matrix. Moreover, the mechanical behaviour of the systems was compared considering two different preparation methods, namely compression and injection moulding. The injection moulded samples show poorer mechanical performances than those of the compression moulded systems. The impact strength significantly improves when PHA is added while it reduces when bacterial biomass is used i…
Hydrolysis rates, methane production and nitrogen solubilisation of grey waste components during anaerobic degradation.
2005
Abstract Municipal grey waste (i.e. the remaining fraction in municipal waste management systems in which putrescibles (biowaste) and other recyclables (paper, metals, glass) are source-segregated) was manually sorted into six main fractions on the basis of composition and also separated by sieving (100 mm mesh size) into two fractions, oversized and undersized, respectively. In practice, in waste management plant the oversized fraction is (or will be) used to produce refuse-derived fuel and the undersized landfilled after biological stabilisation. The methane yields and nitrogen solubilisation of the grey waste and the different fractions (all studied samples were first milled to 5 mm part…
Effects of storage on characteristics and hygienic quality of digestates from four co-digestion concepts of manure and biowaste.
2007
This study evaluated the effects of storage in northern winter conditions (5 degrees C) on the characteristics and nutrients separation of digestates from co-digestion of manure and biowaste as well as the hygienic quality of the digestates after digestion and storage. During 3-11 months' storage average nitrogen losses and reductions of total solids (TS) and volatile solids (VS) were 0-15%. With some exceptions, soluble chemical oxygen demand (SCOD) had increased slightly (from approximately 6.5 to approximately 7.5g/l) after 3 months' storage, while after 9-11 months' it had decreased from 8.3-11 to 5.6-8.4g/l. The concentrations of P(tot) and PO4-P in the separated liquid fractions decre…
Trimeprazine is enantioselectively degraded by an activated sludge in ready biodegradability test conditions
2018
[EN] A great number of available pharmaceuticals are chiral compounds. Although they are usually manufactured as racemic mixtures, they can be enantioselectively biodegraded as a result of microbial processes. In this paper, a biodegradability assay in similar conditions to those recommended in OECD tests of enantiomers of trimeprazine (a phenothiazine employed as a racemate) is carried out. Experiments were performed in batch mode using a minimal salts medium inoculated with an activated sludge (collected from a Valencian Waste Water Treatment Plant, WWTP) and supplemented with the racemate. The concentration of the enantiomers of trimeprazine were monitored by means of a chiral HPLC metho…
Kaļķaino zāļu purvu veģetācijas sukcesija Engures ezera dabas parkā
2015
Eiropā kaļķainu zāļu purvu platības pēdējā gadsimta laikā ir strauji sarukušas, jo tās netiek atbilstoši apsaimniekotas. Dabiskās sukcesijas gaitā šie biotopi aizaug ar kokiem, krūmiem un graudzālēm. Šī tendence vērojama arī Engures ezera dabas parka kaļķainos zāļu purvos. Viena no dabas parka zāļu purvu lielākajām vērtībām ir augstā orhideju sastopamība. Darba mērķis ir noskaidrot sukcesijas ietekmi uz augu sabiedrībām un orhideju cenopopulācijām. Pētījuma ietvaros aprakstīti 787 veģetācijas parauglaukumi. Biežāk sastopamajām orhideju sugām novērtēta vitalitāte un sastopamība. Dabas parka zāļu purva kvalitāte vērtējama kā vidēja, savukārt orhideju vitalitāte kā zema līdz vidēja, bet sastop…
Researching a Capacity Model for Multilane Roundabouts with Negotiation of the Right-of-Way between Antagonist Traffic Flows
2012
This article summarizes a research program designed to assess operating conditions through capacity estimation at not-conventional roundabouts characterized by a central island with a large diameter and by two (or more) entering and circulating lanes. Although giving priority to vehicles on circulatory roadway is the nominal operating rule, on-field observations highlighted that in some infrastructural schemes of the type considered in this research drivers negotiate the right-of-way according to a consensus pattern that alternates between antagonist traffic flows, similarly to that observed at all-way-stop-controlled intersections. Considering the peculiarity of the way of working at round…
Estimation of Measures of Effectiveness (MOE) for the C-Roundabouts
2013
The C-roundabout (cyclist roundabout) is a new multi-lane roundabout designed to improve the safety of cyclists at and make multi-lane roundabouts more cyclist-friendly. The geometric layout of C-Roundabouts allows the decrease of the vehicle speeds through the roundabout to around 30 km/h. The rare C-roundabout installations so far implemented in the world have not allowed analysing the capacity by means empirical data. In the light of this considerations, the main objective of the paper is to give a theoretical closed-form model for evaluation the measures of effectiveness MOE (capacity, delay, queues) of the C-Roundabouts.
Crash modeling for urban roundabouts: a case study
2013
In many cities and towns, a large number of intersections are considered sites with promise for safety and operational improvements. Several studies have been carried out in many countries to establish relationships between crashes and flow and non-flow explanatory variables, using statistical tools to investigate factors critical to road safety. Starting from a brief review of existing information and analysis on the issue, this article summarizes the findings of an exploratory analysis aimed at modeling injury crashes for a sample of urban roundabouts. The methodological path followed in this research allowed to handle issues associated with the estimation of a safety performance function…
A paradigm of extreme rainfall pluvial floods in complex urban areas: the flood event of 15 July 2020 in Palermo (Italy)
2021
Abstract. In the last years, some regions of the Mediterranean area are witnessing a progressive increase in extreme events, such as urban and flash floods, as a response to the increasingly frequent and severe extreme rainfall events and their ground effects, which are often exacerbated by ever-growing urbanization. In such a context, the traditional defense of urban areas, which are usually based on urban drainage systems designed without regard to the impacts of urbanization and climate change on natural systems, may not be sufficient to deal with the risk deriving from the occurrence of such events. This study focuses on a very recent and particularly intense urban flood that occurred i…