997 resultados para Railroad cars.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The current research explores the relationship between people and their cars within the framework of Altman's theory of human territoriality. It further develops the research of Sandqvist by examining the descriptions given by people with differing ownership and uses of their cars and exploring the congruence between these and the characteristics used to describe human territories. Thirteen focus groups were held with young drivers between the ages of 18 and 25 years, drivers over the age of 25 who are parents of pre-license age children, drivers over the age of 25 who do not regularly transport children, and drivers of work vehicles. Analyses of discussions revealed that drivers’ descriptions of the relationship with their car could be matched with Brown and Altman's descriptions of territory types. However, variations existed both between and within individuals as to the application of the labels ‘primary’, ‘secondary’ and ‘public’ territory to the car. Implications for the understanding of road user behaviour and the further development of theory on the car as a place or an object in terms of territoriality are discussed.


Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article reports on the underlying dimensions used by petrol-electric hybrid and conventional car buyers when evaluating a vehicle with the intent to purchase. Buyers of conventionally fuelled vehicles reported that they considered quality and performance as the most important determinants of choice. They rated as least important, the image they derive from driving a particular car and social influence. On the other hand, petrol-electric hybrid car buyers reported that social influence and projecting a “green” image were most important considerations and quality and appeal were least important. These findings provide social marketers with a crucial understanding that helps in the selection of an appropriate model to promote the diffusion of eco-friendly vehicles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In an episode of South Park titled ‘Hey, People, You’ve Gotta Drive Hybrids Already’, Stan convinces townsfolk to buy hybrid cars. This reduces the rate of smog but creates a toxic cloud of ‘smug’. In this paper, I use this parody of eco-correctness to interrogate some of Outdoor Education’s environmental aims. Michel Foucault’s later work on the self, morality and governmentality is used to analyse the production of the [neo- iberal] ‘environmentally responsible citizen’. The possibilities and problems of contemporary citizenship discourse are explored in relation to findings from a longitudinal study of students undertaking a tertiary outdoor and environmental education course.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One way to manage disturbance to waterbirds in natural areas where humans require access is to promote the occurrence of stimuli for which birds tolerate closer approaches, and so cause fewer responses. We conducted 730 experimental approaches to 39 species of waterbird, using five stimulus types (single walker, three walkers, bicycle, car and bus) selected to mimic different human management options available for a controlled access, Ramsar-listed wetland. Across species, where differences existed (56% of 25 cases), motor vehicles always evoked shorter flight-initiation distances (FID) than humans on foot. The influence of stimulus type on FID varied across four species for which enough data were available for complete cross-stimulus analysis. All four varied FID in relation to stimuli, differing in 4 to 7 of 10 possible comparisons. Where differences occurred, the effect size was generally modest, suggesting that managing stimulus type (e.g. by requiring people to use vehicles) may have species-specific, modest benefits, at least for the waterbirds we studied. However, different stimulus types have different capacities to reduce the frequency of disturbance (i.e. by carrying more people) and vary in their capacity to travel around important habitat

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We tested the 'cars cause less disturbance' hypothesis by comparing the flight-initiation distance (FID) evoked by a car versus a single walker for 38 species of waterbird (n = 657 standardised approaches). For the 15 species where we had sample size adequate for statistical testing (n ≥ 5), we found that cars elicited shorter responses after controlling for starting distance. Within-species analyses revealed that this difference was significant in 8 of 15 species. Although mean FIDs for car approaches were always shorter than FIDs toward single walkers in the remaining species (7), the tests in those species lacked sufficient power to draw meaningful conclusions. Our results provide support for the hypothesis that birds respond to cars at shorter distances. The wide taxonomic breadth of species investigated suggests that this principle may be broadly applicable, at least in waterbirds. The results of this study and the FID estimates we present will allow development of meaningful stimulus-specific buffer zones to protect waterbirds from disturbance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The luciferases of the railroad worm Phrixotrix (Coleoptera: Phengodidae) are the only beetle luciferases that naturally produce true red bioluminescence. Previously, we cloned the green- (PxGR) and red-emitting (PxRE) luciferases of railroad worms Phrixotrix viviani and P. hirtus[OLE1]. These luciferases were expressed and purified, and their active-site properties were determined. The red-emitting PxRE luciferase displays flash-like kinetics, whereas PxGR luciferase displays slow-type kinetics. The substrate affinities and catalytic efficiency of PxRE luciferase are also higher than those of PxGR luciferase. Fluorescence studies with 8-anilino-1-naphthalene sulfonic acid and 6-p-toluidino-2-naphthalene sulfonic acid showed that the PxRE luciferase luciferin-binding site is more polar than that of PxGR luciferase, and it is sensitive to guanidine. Alutagenesis and modelling studies suggest that several invariant residues in the putative luciferin-binding site of PxRE luciferase cannot interact with excited oxyluciferin. These results suggest that one portion of the luciferin-binding site of the red-emitting luciferase is tighter than that of PxGR luciferase, whereas the other portion could be more open and polar.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To find the regions having a major influence on the bioluminescence spectra of railroad worm luciferases, we constructed new chimeric luciferases switching the fragments from residues 1-219 and from 220-545 between Phrixotrix viviani (PxvGR; λmax = 548 nm) green light-emitting luciferase and Phrixothrix hirtus (PxhRE; λmax = 623 nm) red light-emitting luciferases. The emission spectrum (λmax = 571 nm) and KM for luciferin in the chimera PxRE220GR (1-219, PxhRE; 220-545, PxvGR) suggested that the region above residue 220 of PxvGR had a major effect on the active site. However, switching the sequence between the residues 226-344 from PxvGR luciferase into PxhRE (PxREGRRE) luciferase resulted in red light emission (λmax = 603 nm), indicating that the region 220-344 by itself does not determine the emission spectrum. Furthermore, the sequence before residue 220 of the green-emitting luciferase is incompatible for light emission with the sequence above residue 220 of PxhRE. These results suggest that the fragments before and after residue 220, which correspond to distinct subdomains, may fold differently in the green- and red-emitting luciferases, affecting the active site conformation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper is the result of real-scale physical modeling study designed to simulate the load-deformation characteristics of railroad foundation systems that include the railroad ties, the ballast, and the sub-base layers of a railroad embankment. The study presents comparisons of the application of dynamic loads of 100kN on the rails, and the resulting deformations during a 500,000 cycle testing period for three rail support systems; wood, concrete and steel. The results show that the deformation curve has an exponential shape, with the larger portion of the deformation occurring during the first 50,000 load cycles followed by a tendency to stabilize between 100,000 to 500,000 cycles. These results indicate that the critical phase of deformations of a new railroad is within the first 50,000 cycles of loading, and after that, it slowly attenuates as it approaches a stable value. The paper also presents empirically derived formulations for the estimation of the deformations of the rail supports as a result of rail traffic.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper analyses the static and dynamic behavior of the railroad track model in laboratory. Measurements of stresses and strains on a large-scale railroad track apparatus were studied. The model includes: compacted soil, representing the final layers of platform, ballast layer, and ties (steel, wooden, and pre-stressed concrete). The soil and soil ballast interface were instrumented with pneumatic stress gauge. Settlement measurement device were positioned at the same levels as the load cells. Loads were applied by hydraulic actuators, statically and dynamically. After the prescribed number of load cycles, in pre-determined intervals, stresses and strains were measured. Observations indicate that stress and strain distributions, transmitted by wooden or steel ties, behave similarly. A more favorable behavior was observed with pre-stressed concrete mono block ties. Non-linear response was observed after a threshold numbers of cycles were surpassed, showing that the strain modulus increases with the numbers of cycles. © 2009 IOS Press.