Search results for "R40"
showing 8 items of 8 documents
On-site Experimental Study of HCFC-22 Substitution with HFCs Refrigerants
2012
Abstract The European Regulation no 2037/2000 has banned manufacturing HCFC refrigerants from January 1st 2010, although its use is allowed up to 2015 if the fluids come from a recycling process. This situation creates the need for developing new working fluids to replace the HCFC in the refrigeration plants now in operation. Among all the HCFCs the R22 is the most widely used in a wide range of applications, especially in air conditioning. This paper presents the results of an experimental analysis comparing the performance of a vapour compression refrigerating unit operating with R22, and its performance in comparison to some HFCs fluids, substituting the former. In particular, the plant …
Transport, mondialisation, développement urbain et régional. Introduction au dossier
2007
La nodalité : un concept fondamental de l’organisation de l’espace. Introduction au dossier
2005
Quel rôle du réseau de voirie urbaine sur la distribution des flux piétonniers ?
2007
In the urban networks, the pedestrian frequency of streets is variable. At an aggregated level, it partially depends on the spatial configuration of the urban network. This concept, called the “natural movement”, is a key-notion in space syntax. It is here investigated by assuming several explanatory factors: metric accessibility, network linearity, route linearity, route continuity. Data obtained from a pedestrian movement survey in the city of Lille (France) were used. The factors were represented by series of theoretical frequencies defined with origin and destination points stemmed from real trips. These theoretical frequencies were compared to the observed pedestrian frequencies. The s…
Paysages et choix d'itinéraires pédestres en milieu urbain. Une nouvelle approche par les bifurcations
2007
Walking has long been neglected in urban mobility research. In the context of a sustainable mobility, it is now included into numerous works including various approaches. The well-known models of flows affectation are often used to study the behaviour of pedestrians and to identify their preferences. However, the factors that are usually chosen to describe the urban environment are usually limited or inappropriate to the pedestrian movement. In addition, these models assume that the choices made by pedestrians are predetermined at the start of each trip, without any possible decision intervening along these trips. In this paper, we propose to test the role of urban landscape by using a new …
Comment réduire les émissions de CO2 du transport de fret en France ? Évaluation socio-économique de trois politiques publiques
2018
France must implement voluntarist policies in order to reduce CO2 emissions, which raises questions regarding the effectiveness of competing options and their costs, for both public finances and society. This paper estimates abatement costs of one ton of CO2 from three scenarios aimed at softening the environmental impacts of freight moved by trucks. Hybrid trucks may generate large CO2 savings (5.7 Mt/year in 2030), at a moderate discounted abatement cost (88 €/t). The option based on natural gas for vehicles leads to a similar abatement cost and to lower environmental gains (3.2 Mt/year in 2030). Whilst inducing small CO2 savings (0.2 Mt/year in 2030), megatrucks present a negative discou…
An experimental study of a refrigerating plant when replacing R22 with HFCs refrigerants
2011
This paper presents the results of an experimental analysis comparing the performance of a vapour compression refrigerating unit operating with R22, and its performance in comparison to some HFCs fluids, substituting the former according to reg. n. 2037/2000. In particular, the plant working efficiency was first tested with R22 and then with three HFC fluids: R417A, R407C and R404A. The investigation verified that the performance with HFCs refrigerants did not result as efficient as when using R22. An environmental analysis also was performed.
Vertical integration and exclusivities in maritime freight transport
2011
A key recent theme in maritime freight transport is the involvement of shipping lines in terminal management. Such investments are costly but allow liners to provide better service. Most of these new terminals are dedicated terminals but some are non-exclusive and let rivals access them for a fee. In this paper, we show that a shipping line that builds its own terminal finds it strategically profitable (i) to continue routing part of its cargo through the open port facilities, and (ii) to keep its terminal non-exclusive. In this way, the liner investor pushes part of the rival's freight from the open to the new terminal. Besides, under non-exclusivities, the shipping lines offer a wider var…