Increasing evacuation flow through school bus emergency roof hatches.

Appl Ergon

Department of Industrial & Systems Engineering, 3301 Shelby Center, Auburn University, AL, 36849, USA. Electronic address:

Published: October 2020

Emergency escape roof hatches are used to evacuate school buses in rolled-over orientations. In the United States, the minimum opening size of a roof hatch is defined by Federal Motor Vehicle Safety Standard (FMVSS) no. 217. With the prevalence of rising obesity rates among children, the minimum roof hatch opening size may not be large enough to accommodate larger passengers. Post-accident conditions such as injuries, disorientation, and exit obstructions may also prevent unobstructed passage for egress within acceptable time limits. The purpose of this study was to redesign and fabricate a roof hatch with a larger opening and evaluate its egress characteristics for a range of typical school bus passengers. The larger roof hatch opening allows greater evacuation flow rates, and is almost functionally equivalent to the evacuation flow rate of the front door on an upright school bus.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.apergo.2020.103178DOI Listing

Publication Analysis

Top Keywords

roof hatch
16
evacuation flow
12
school bus
12
roof hatches
8
opening size
8
hatch opening
8
roof
6
increasing evacuation
4
school
4
flow school
4

Similar Publications

A challenge remains in achieving adequate surface roughness of SLM fabricated interior channels, which is crucial for fuel delivery in the space industry. This study investigated the surface roughness of interior fine flow channels (1 mm diameter) embedded in SLM fabricated TC4 alloy space components. A machine learning approach identified layer thickness as a significant factor affecting interior channel surface roughness, with an importance score of 1.

View Article and Find Full Text PDF

Future climatic scenarios forecast increases in average temperatures as well as in the frequency, duration, and intensity of extreme events, such as heatwaves. Whereas behavioral adjustments can buffer direct physiological and fitness costs of exposure to excessive temperature in wild animals, these may prove more difficult during specific life stages when vagility is reduced (e.g.

View Article and Find Full Text PDF

Embryonic development of the skull in a parthenogenetic lizard, the mourning gecko (Lepidodactylus lugubris).

J Anat

October 2023

Department of Evolutionary Biology and Conservation of Vertebrates, Faculty of Biological Sciences, University of Wrocław, Wrocław, Poland.

Gekkotans are one of the major clades of squamate reptiles. As one of the earliest-diverging lineages, they are crucial in studying deep-level squamate phylogeny and evolution. Developmental studies can shed light on the origin of many important morphological characters, yet our knowledge of cranial development in gekkotans is very incomplete.

View Article and Find Full Text PDF

Developmental origins of the crocodylian skull table and platyrostral face.

Anat Rec (Hoboken)

October 2022

Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA.

Article Synopsis
  • The dorsoventrally flattened skull of modern crocodilians is an adaptation for their semi-aquatic feeding habits, and its developmental origins are largely unexplored.
  • A study involving 103 extant crocodilian species used geometric morphometrics to analyze both embryonic development and post-hatching growth of their skulls, revealing that embryonic skull shapes are conserved across different ecomorphs.
  • The findings indicate that significant developmental changes occur right before hatching, with the flattened skull fully formed by the end of embryonic development, suggesting that both selection pressures for hatchling performance and constraints in skull shape played a role in this conservation pattern, possibly dating back over 200 million years.
View Article and Find Full Text PDF

Embryonic staging tables provide a standard of developmental stages that can be used by individual investigators and provide approximate time points for the study of developmental phenomena. Surprisingly, despite the presence of a plethora of studies on the chicken skull and its role as a model species in developmental research, a staging table of the development of the chicken skull remains lacking. A detailed photographic staging table of the osseous portion of the chicken skull is thus presented here based on cleared and stained HH stages spanning HH 35 (first appearance of skull ossification) to the final stage before hatching (HH 45).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!