scholarly journals Assessment of the potential impact of embedded radioactive fragments following the use of a crude radiological dispersal device (‘dirty bomb’)

2020 ◽  
Vol 40 (4) ◽  
pp. 1217-1235
Author(s):  
Laurence Jones ◽  
Donna Moor ◽  
Thomas Peacock ◽  
Thomas Melley ◽  
Crawford Foster ◽  
...  
Keyword(s):  
Dirty Bomb ◽  
Potential Impact ◽  
Radiological Dispersal

scholarly journals CHALLENGES FOR PHYSICS-BASED MODELS OF A RADIONUCLIDE DISPERSAL DEVICE

2019 ◽  
Vol 8 (1) ◽  
pp. 83-85
Author(s):  
David William Hummel ◽  
Lucian Ivan
Keyword(s):  
Terrorist Attack ◽  
Decision Makers ◽  
High Fidelity ◽  
Effective Response ◽  
Response Strategies ◽  
Dirty Bomb ◽  
Highly Sensitive ◽  
The Subject ◽  
Emergency Decision ◽  
Radiological Dispersal

A “dirty bomb” is a type of hypothetical radiological dispersal device (RDD) that has been the subject of significant safety and security concerns given the disruption that would result in a postulated terrorist attack. Reliable and accurate predictions of dispersion of radiological material from an RDD are absolutely necessary for first responders and emergency decision makers to plan effective response strategies. Development of high-fidelity, mechanistic models of a dirty bomb are complicated because dispersion over areas with the greatest risk of contamination is highly sensitive to the source of contaminant particles, and this source term is governed by processes over much smaller temporal and spatial length scales than the dispersion. New work on accelerating high-fidelity models of RDDs has been initiated that looks to incorporate the multiscale aspects of the problem and enhance predictive capabilities that may assist in anti-terrorism activities.

Prevalence of Radioactive Signals from Surveillance of an Emergency Department

2006 ◽  
Vol 21 (4) ◽  
pp. 276-281
Author(s):  
Frank Guyette ◽  
Joe Suyama ◽  
Jerry Rosen ◽  
Michael Allswede
Keyword(s):  
Emergency Department ◽  
Background Radiation ◽  
Radiation Detector ◽  
Healthcare Setting ◽  
Radiation Detectors ◽  
The United States ◽  
Mean Value ◽  
Dirty Bomb ◽  
Radiological Dispersal ◽  
Terrorist Event

AbstractIntroduction:Since the 11 September 2001 terrorist attacks in the United States, concerns have been raised regarding the threat of a radiological terrorist weapon. Although the probability of the employment of a nuclear device is remote, the potential of a radiological dispersal device (RDD) or “dirty bomb” is of concern. While it is unlikely that such a device would produce massive numbers of casualties, it is far more likely that it would result in pub- lic panic and perhaps even disable the local healthcare system. The utility of surveillance with radiation detectors in the healthcare setting has not been fully evaluated.Objective:The objective of this study was to characterize the prevalence of radioactive sources entering an urban emergency department (ED).Methods:A retrospective review of data obtained from a radiation detector positioned to detect radioactive people entering an ED of an urban academic hospital that serves 45,000 patients/year was performed. Graphical outputs of radioactivity were recorded in Microsoft ExcelTM (Microsoft, Redmond, WA, US) spreadsheets in microREM/hour. Data were collected continuous-ly from 22 December 2003 to 22 January 2004. An event was defined as any elevation in radiation levels >95% confidence interval from the mean level of background radiation over 72 hours (h).Results:A total of 215 events were observed over a 28-day period, with a mean value of 7.7 events/day, and a maximum of 15 events/day. During the 28-day period, the baseline mean level of background radiation was 2–4 microREM/h. Readings ranged from 2,148.28–17,292.25 microREM/h with a maximum sustained detector exposure of 684.37 microREM. Distinct signal patterns were seen at both detectors including tonic, phasic, dual, and short duration spikes.Conclusion:The number of radioactive signals detected from persons entering the ED was much higher than expected. While the vast majority of these signals pose no health threat, they may make routine screening for a radiological terrorist event difficult.Further study is needed to determine this correlation.

scholarly journals Establishing Remediation Levels in Response to a Radiological Dispersal Event (or “Dirty Bomb”)

2004 ◽  
Vol 38 (9) ◽  
pp. 2505-2512 ◽  
Author(s):  
Deborah Elcock ◽  
Gladys A. Klemic ◽  
Anibal L. Taboas
Keyword(s):  
Dirty Bomb ◽  
Radiological Dispersal

Effects of Gender, Parental Role, and Time on Infant- and Adult-Directed Read and Spontaneous Speech

2019 ◽  
Vol 62 (11) ◽  
pp. 4001-4014
Author(s):  
Melanie Weirich ◽  
Adrian Simpson
Keyword(s):  
Parental Involvement ◽  
Gender Identity ◽  
Spontaneous Speech ◽  
First Year ◽  
Space Size ◽  
Vowel Space ◽  
Potential Impact ◽  
Phonetic Features ◽  
And Gender ◽  
Description Task

Purpose The study sets out to investigate inter- and intraspeaker variation in German infant-directed speech (IDS) and considers the potential impact that the factors gender, parental involvement, and speech material (read vs. spontaneous speech) may have. In addition, we analyze data from 3 time points prior to and after the birth of the child to examine potential changes in the features of IDS and, particularly also, of adult-directed speech (ADS). Here, the gender identity of a speaker is considered as an additional factor. Method IDS and ADS data from 34 participants (15 mothers, 19 fathers) is gathered by means of a reading and a picture description task. For IDS, 2 recordings were made when the baby was approximately 6 and 9 months old, respectively. For ADS, an additional recording was made before the baby was born. Phonetic analyses comprise mean fundamental frequency (f0), variation in f0, the 1st 2 formants measured in /i: ɛ a u:/, and the vowel space size. Moreover, social and behavioral data were gathered regarding parental involvement and gender identity. Results German IDS is characterized by an increase in mean f0, a larger variation in f0, vowel- and formant-specific differences, and a larger acoustic vowel space. No effect of gender or parental involvement was found. Also, the phonetic features of IDS were found in both spontaneous and read speech. Regarding ADS, changes in vowel space size in some of the fathers and in mean f0 in mothers were found. Conclusion Phonetic features of German IDS are robust with respect to the factors gender, parental involvement, speech material (read vs. spontaneous speech), and time. Some phonetic features of ADS changed within the child's first year depending on gender and parental involvement/gender identity. Thus, further research on IDS needs to address also potential changes in ADS.

Exploring the Potential Impact of Sentence-Level Comprehension and Sentence-Level Fluency on Deaf Students' Passage Comprehension

2020 ◽  
Vol 63 (7) ◽  
pp. 2281-2292
Author(s):  
Ying Zhao ◽  
Xinchun Wu ◽  
Hongjun Chen ◽  
Peng Sun ◽  
Ruibo Xie ◽  
...  
Keyword(s):  
Independent Predictor ◽  
Vocabulary Knowledge ◽  
Group Differences ◽  
Regression Analyses ◽  
Deaf Students ◽  
Mediating Role ◽  
Sentence Level ◽  
Mediating Mechanisms ◽  
Potential Impact ◽  
The Relationship

Purpose This exploratory study aimed to investigate the potential impact of sentence-level comprehension and sentence-level fluency on passage comprehension of deaf students in elementary school. Method A total of 159 deaf students, 65 students ( M age = 13.46 years) in Grades 3 and 4 and 94 students ( M age = 14.95 years) in Grades 5 and 6, were assessed for nonverbal intelligence, vocabulary knowledge, sentence-level comprehension, sentence-level fluency, and passage comprehension. Group differences were examined using t tests, whereas the predictive and mediating mechanisms were examined using regression modeling. Results The regression analyses showed that the effect of sentence-level comprehension on passage comprehension was not significant, whereas sentence-level fluency was an independent predictor in Grades 3–4. Sentence-level comprehension and fluency contributed significant variance to passage comprehension in Grades 5–6. Sentence-level fluency fully mediated the influence of sentence-level comprehension on passage comprehension in Grades 3–4, playing a partial mediating role in Grades 5–6. Conclusions The relative contributions of sentence-level comprehension and fluency to deaf students' passage comprehension varied, and sentence-level fluency mediated the relationship between sentence-level comprehension and passage comprehension.

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