Calculation of Heavy Truck Deceleration Based on Air Pressure Rise-Time and Brake Adjustment

2004 ◽  
Author(s):  
Wade D. Bartlett
Keyword(s):  
Rise Time ◽  
Pressure Rise ◽  
Air Pressure ◽  
Heavy Truck

Gaseous Deflagration in Piping: Part 2 — Proposed Methods and Code Acceptance Criteria

2017 ◽  
Author(s):  
John C. Minichiello ◽  
Thomas C. Ligon ◽  
David J. Gross
Keyword(s):  
Rise Time ◽  
Lower Energy ◽  
Waste Treatment ◽  
Pressure Rise ◽  
Piping System ◽  
Frequent Event ◽  
Piping Systems ◽  
Hydrogen Accumulation ◽  
Induced Stresses ◽  
Detonation Loading

This paper proposes Piping Code rules to address the effects of hydrogen deflagrations inside piping. Previous work proposed a set of criteria for piping subject to detonation loading [PVP2012-78519, PVP2012-78525]. This paper provides criteria to evaluate the effect of deflagrations, which typically have a slower rise time and lower energy, inside the piping. These deflagration criteria, coupled with the previously cited detonation criteria, are being used at the Hanford Tank Waste Treatment and Immobilization Plant to evaluate piping systems subject to hydrogen accumulation. The previous papers did not investigate or propose criteria for deflagrations, as these were known to have lower pressures and slower pressure rise times, but are still of some significance for piping design. Recent work has shown that there exists a scenario in which the deflagration loading may be very significant: deflagrations in small gas pockets surrounded by large waste slugs. Depending on the assumptions used to develop the loading, the unbalanced forces on piping segments in a long piping system can become high during a deflagration event. Thus, for the set of criteria chosen for deflagration, the deflagration event may become the limiting event, especially if it is the more frequent event. The criteria proposed need to recognize this scenario and guide the user to possible solutions. This paper presents the original methodology for evaluating these “slug” events, briefly discusses the recent testing and theory being pursued to reduce the effect of the loading [PVP2015-45970, PVP2016-63260, PVP2016-63262], and then proposes criteria for evaluating deflagration induced stresses and loads.

Heavy Truck and Bus Brake Testing: The Development and Use of a Forensic Tool

2008 ◽  
Author(s):  
Christopher W. Ferrone
Keyword(s):  
Test Methods ◽  
Air Pressure ◽  
Brake System ◽  
System Failure ◽  
Parking Brake ◽  
Heavy Truck ◽  
The Common ◽  
Common Problems ◽  
Air Brakes ◽  
Accident Conditions

After an accident it is often necessary to check the brake push rod stroke adjustment and pneumatic integrity of the brake system of a truck or bus. In many instances, due to the traumatic accident damage, the brake system may not be able to be tested/checked by the conventional means. Test methods used at the scene of an accident may compromise or influence the brake stroke adjustment levels. A tool has been developed which eliminates these issues. This tool, when used to test air brakes (push-rod stroke) on a heavy truck or bus, will eliminate the common problems and difficulties that occur during brake stroke adjustment testing in a post-accident situation. • Checking brake push rod stroke with improper air pressure levels; • System leaks creating measurement inaccuracies; • Parking brake release issues; • System interruption due to traumatic accident damage. By using this tool an engineer can determine the brake push rod stroke adjustment level or diagnose a system failure in an efficient and nondestructive manner, by minimizing the alteration of post-accident conditions.

Effect of pressure rise time on tidal volume and gas exchange during pressure control ventilation

2000 ◽  
Vol 48 (5) ◽  
pp. 766
Author(s):  
Byung O Jeong ◽  
Youn Suck Koh ◽  
Tae Sun Shim ◽  
Sang Do Lee ◽  
Woo Sung Kim ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Tidal Volume ◽  
Rise Time ◽  
Pressure Rise ◽  
Pressure Control ◽  
Control Ventilation ◽  
Pressure Control Ventilation ◽  
Effect Of Pressure

Effect of pressure rise time on ventilator parameters and gas exchange during neonatal ventilation

2020 ◽  
Vol 55 (5) ◽  
pp. 1131-1138 ◽  
Author(s):  
David Chong ◽  
Sabrina Kayser ◽  
Eniko Szakmar ◽  
Colin J. Morley ◽  
Gusztav Belteki
Keyword(s):  
Gas Exchange ◽  
Rise Time ◽  
Pressure Rise ◽  
Effect Of Pressure ◽  
Neonatal Ventilation

Physiologic Stages of Vocal Reaction Time

1984 ◽  
Vol 27 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Thomas Shipp ◽  
Krzysztof Izdebski ◽  
Philip Morrissey
Keyword(s):  
Reaction Time ◽  
Pressure Rise ◽  
Normal Subjects ◽  
Air Pressure ◽  
Central Processing ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles ◽  
Male Subjects ◽  
Vocal Reaction Time

A simple vocal reaction time (RT) task was performed by 10 male subjects while measures from intrinsic laryngeal muscles and subglottal air pressure were obtained simultaneously. Based only on each subject's fastest time among 15 trials, RT values were similar to the latencies previously observed in normal subjects. The mean of the subjects' fastest trials was 185 ms (range: 160–250ms). Shortest latency values obtained for each measure were interarytenoid muscle, 50 ms; thyroarytenoid muscle, 60 ms; posterior cricoarytenoid muscle, 80 ms; subglottal air pressure rise, 125 ms. From these data estimates were made of 115 ms for the shortest respiratory system latency and 25 ms for the minimal central processing time. These data suggest that fastest vocal RTs are determined principally by the temporal constraints involved in activating pulmonary rather than laryngeal structures.

Possibilistic Analysis of Structural Systems Subjected to Blast Loads

2003 ◽  
Author(s):  
Hari B. Kanegaonkar
Keyword(s):  
Pulse Duration ◽  
Rise Time ◽  
Peak Pressure ◽  
Pressure Rise ◽  
Structural Response ◽  
Offshore Structures ◽  
Blast Loads ◽  
Safety Level ◽  
Ignition Point ◽  
Blast Pulse

The accidental release of the hydrocarbons and the possibility of resulting explosion have to be taken into account while designing the topside systems of the offshore structures. Determination of design explosion loads for the topside structures is a complex task since it involves several sources of uncertainty. Dimensioning of blast loads is important in achieving the desired safety level against the structural failure and related consequences. The design loads must incorporate uncertainties due to variability in the ignition point location, the type of ignition source, the volume of the gas released and the characteristics of the gas cloud etc. These uncertainties which are not statistical in nature may not be categorised as random or probabilistic but are cognitive and fuzzy in nature. The probabilistic framework for structural analysis subjected to blast loads could be quite cumbersome due to high number of uncertain variables and complex interdependency. The uncertainty in the load and corresponding uncertainty in the structural response can either be predicted from variations in the uncertain load parameters — a sensitivity evaluation or through a compact “possibilistic analysis”. The blast loads are usually defined as a triangular pulse through peak pressure, rise time and the blast pulse duration as the parameters. In the present investigation, the parameters in the triangular blast load description are assumed fuzzy. The peak pressure, rise time and blast pulse duration are defined using triangular fuzzy numbers. The possibilistic dynamic response of simple structural system — beam — used in the blast wall is obtained using single-degree of freedom approximation. It is shown that the possibilistic response provides rational decision making tool to arrive at desired safety level.

Experimental Analysis of Minimum Ignition Temperature of Dust Cloud Obtained from Thermally Modified Spruce Wood

2014 ◽  
Vol 919-921 ◽  
pp. 2057-2060
Author(s):  
Jaroslav Zigo ◽  
Peter Rantuch ◽  
Karol Balog
Keyword(s):  
Ignition Temperature ◽  
Dust Cloud ◽  
Pressure Rise ◽  
Dust Sample ◽  
Air Pressure ◽  
Sample Weight ◽  
Dust Clouds ◽  
Spruce Wood ◽  
Minimum Ignition Temperature

This article deals with study of minimum ignition temperature (MIT) of thermally modified spruce dust. Dust of several species of spruce was mixed, sieved, dried and subjected to Thermo-S temperature programme. Samples of dust (200 250 μm) were tested in Goldbert-Greenwald furnace apparatus for determination of the MIT of dust clouds. The influence of air pressure and sample weight to the MIT was studied. The results show that the MIT of thermally modified spruce dust gradually decreases as the sample weight and air pressure rise. The lowest value of MIT (470 °C) was measured, when the air pressure was 50 kPa and the sample weight 0,5 g. To reach even lower values of MIT (˂468 °C), the air pressure should gradually rise to approx. 42 46 kPa and the weight of dust sample should be approx. 0,46 0,53 g.

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