Designing a Site Electrical System With Arc Flash Energy Under 20 $ \hbox{cal}/\hbox{cm}^{2}$

2009 ◽  
Vol 45 (3) ◽  
pp. 1180-1183 ◽  
Author(s):  
Daniel R. Doan
Keyword(s):  
Electrical System ◽  
Arc Flash ◽  
A Site

AC and DC Arc Flash Analysis for an Industrial Electrical System Infrastructure and Its Importance

2021 ◽  
Author(s):  
Jehan Perera ◽  
Nkiru L. Agu ◽  
Gobind G. Pillai ◽  
Musbahu Muhammad ◽  
Gill Lacey
Keyword(s):  
Electrical System ◽  
Arc Flash ◽  
Dc Arc

"Having a Blast" - Assessment of Compartment Overpressure following an Arc Fault

2018 ◽  
Author(s):  
A Lane ◽  
P Worthington ◽  
I Thompson ◽  
W Galloway ◽  
G Stark
Keyword(s):  
Spatial Representation ◽  
Pressure Rise ◽  
System Modelling ◽  
Guidance Document ◽  
Electrical System ◽  
Level Data ◽  
Personnel Safety ◽  
Arc Flash ◽  
Conference Papers ◽  
Previous Conference

The assessment of arc flash incident energy and the mitigation of the associated hazards in naval platform applications is now well defined and understood, with many previous conference papers having been presented, supported by published guidance notes and standards, such as IEEE1584, NFPA 70E, BR2000(52)-1 and Lloyd’s Register Arc Flash guidance document. However, the assessment of the resultant effects of any arc blast on compartment overpressure and the mitigation of the associated hazards to ships structure and ship’s staff are not yet well defined or understood. Literature indicated that considerable damage could be caused to brick built substations and concern was raised about the possible impact on ship structure and personnel safety. With the above in mind, BAE Systems Naval Ships has developed a modelling tool for assessing the effects of an arc blast on a switchboard room compartment and any personnel that may be within the blast boundary. The toolset uses a spatial representation of the switchboard room being assessed, along with the electrical system fault level data, calculated through the normal power system modelling activities, to calculate the pressure rise resulting from an arcing fault. The developed modelling tool allows engineers the ability to perform calculations of arc blast pressure rise for the purpose of identifying the degree of hazard due to pressure and identifying applicable mitigation activities.

Eels Under Standing Wave Conditions

1982 ◽  
Vol 40 ◽  
pp. 492-495
Author(s):  
O.L. Krivanek ◽  
J. TaftØ
Keyword(s):  
Standing Wave ◽  
Wave Conditions ◽  
Set Up ◽  
A Site ◽  
Complex Crystal

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.

Head Size and DNA Content in Bacteriophage T4

1972 ◽  
Vol 30 ◽  
pp. 200-201
Author(s):  
Fred Eiserling ◽  
A. H. Doermann ◽  
Linde Boehner
Keyword(s):  
Electron Microscopy ◽  
Dna Content ◽  
Bacteriophage T4 ◽  
Head Size ◽  
Virus Particles ◽  
Altered Protein ◽  
A Cell ◽  
Bacterial Viruses ◽  
A Site ◽  
Protein Shell

The control of form or shape inheritance can be approached by studying the morphogenesis of bacterial viruses. Shape variants of bacteriophage T4 with altered protein shell (capsid) size and nucleic acid (DNA) content have been found by electron microscopy, and a mutant (E920g in gene 66) controlling head size has been described. This mutant produces short-headed particles which contain 2/3 the normal DNA content and which are non-viable when only one particle infects a cell (Fig. 1).We report here the isolation of a new mutant (191c) which also appears to be in gene 66 but at a site distinct from E920g. The most striking phenotype of the mutant is the production of about 10% of the phage yield as “giant” virus particles, from 3 to 8 times longer than normal phage (Fig. 2).

Exploration-Stage Implementation Variation

2014 ◽  
Vol 222 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Stephanie Romney ◽  
Nathaniel Israel ◽  
Danijela Zlatevski
Keyword(s):  
Parent Training ◽  
Average Cost ◽  
Cost Savings ◽  
Training Group ◽  
Group Differences ◽  
Triple P ◽  
Community Based ◽  
Parent Training Program ◽  
A Site ◽  
The Cost

The present study examines the effect of agency-level implementation variation on the cost-effectiveness of an evidence-based parent training program (Positive Parenting Program: “Triple P”). Staff from six community-based agencies participated in a five-day training to prepare them to deliver a 12-week Triple P parent training group to caregivers. Prior to the training, administrators and staff from four of the agencies completed a site readiness process intended to prepare them for the implementation demands of successfully delivering the group, while the other two agencies did not complete the process. Following the delivery of each agency’s first Triple P group, the graduation rate and average cost per class graduate were calculated. The average cost-per-graduate was over seven times higher for the two agencies that had not completed the readiness process than for the four completing agencies ($7,811 vs. $1,052). The contrast in costs was due to high participant attrition in the Triple P groups delivered by the two agencies that did not complete the readiness process. The odds of Triple P participants graduating were 12.2 times greater for those in groups run by sites that had completed the readiness process. This differential attrition was not accounted for by between-group differences in participant characteristics at pretest. While the natural design of this study limits the ability to empirically test all alternative explanations, these findings indicate a striking cost savings for sites completing the readiness process and support the thoughtful application of readiness procedures in the early stages of an implementation initiative.

DISTRIBUTION OF STRAINS AT Fe2+A SITE IN THE THIOSPINEL FeSc2S4

1976 ◽  
Vol 37 (C6) ◽  
pp. C6-23-C6-28 ◽  
Author(s):  
L. BROSSARD ◽  
H. OUDET ◽  
P. GIBART
Keyword(s):  
A Site

Technical textiles for protection against Arc-flash fire: Savesplash®

2020 ◽  
pp. 67-78
Author(s):  
Nandan Kumar ◽  
Sainath Shrikant Pawaskar
Keyword(s):  
Attenuation Factor ◽  
Threshold Energy ◽  
Single Layer ◽  
Weather Conditions ◽  
Electric Arc ◽  
Risk Category ◽  
Technical Textiles ◽  
Flash Fire ◽  
Level 3 ◽  
Arc Flash

Flash fire caused by electric arc is different than that caused by flammable liquids/fumes or combustible dusts. A suitable protective clothing for protection against electric arc-flash must be designed as per Indian weather conditions. Currently available garments are manufactured using two or three layers of woven/nonwoven combinations to achieve higher Hazard Risk Category (HRC) rating (level 3 and above). However, they are heavy and not comfortable to the end users. Savesplash® is a single layer inherent flame-retardant knitted fabric. Its arc rating was determined using ASTM standards. It achieved arc thermal performance value (ATPV) of 41 cal/cm2, breakopen threshold energy (E_BT) of 42 cal/cm2 and heat attenuation factor (HAF) of 94% when tested as per ASTM F1959/F1959M-14 which translated into an arc rating of 41 cal/cm2. This is equivalent to HRC level 4 ratings as per National Fire Protection Association’s NFPA 70E standard (USA). Further, cut and sewn gloves (HM-100) developed using Savesplash® fabric reinforced with leather on palm area achieved ATPV of 63 cal/cm2 and HAF of 94.5% when tested as per ASTM F2675/F2675M-13.

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