Case Study of Certification of Small Quantities of RAM: Comparison With SGQ Concept

2011 ◽  
Author(s):  
Glenn Abramczyk ◽  
James Shuler ◽  
Steven J. Nathan ◽  
Allen C. Smith
Keyword(s):  
Radiation Dose ◽  
Dose Rate ◽  
Large Dose ◽  
Hazardous Materials ◽  
Photon Radiation ◽  
Radiation Hazard ◽  
Functional Requirements ◽  
Radioactive Materials ◽  
Regulatory Limits

The Small Gram Quantity (SGQ) concept is based on the understanding that small amounts of hazardous materials, in this case radioactive materials, are significantly less hazardous than large amounts of the same materials. The essential functional requirements for RAM packaging are containment of the material, ensuring sub-criticality, and ensuring that the radiation hazard of the package, as represented by the radiation dose for the package, is within the regulatory limits. Knowledge of the composition of the material being shipped is also required. By placing the contents in a containment vessel which is helium leaktight, and limiting the mass so that subcriticality is ensured, the first two requirements are readily met. Some materials emit sufficiently strong photon radiation that a small amount of material can yield a large dose rate. Foreknowledge of the dose rate which will be present for a proposed content is a challenging issue for the SGQ approach. Issues associated with certification for several cases of contents which fall within the SGQ envelop are discussed.

Outdoor Background Radiation Levels in Mining Locations and Major Activity Areas of Ebonyi State, South-Eastern, Nigeria and Their Radiological Impacts

2021 ◽  
Vol 11 (12) ◽  
pp. 65-69
Author(s):  
Sunday Elijah Igwe ◽  
Hyacienth Uche Chiegwu ◽  
Christopher Chukwuemeka Ohagwu
Keyword(s):  
Radiation Dose ◽  
Cancer Risk ◽  
Dose Rate ◽  
Background Radiation ◽  
Radiation Hazard ◽  
Radiation Monitor ◽  
Major Activity ◽  
Mining Areas ◽  
The Mean ◽  
Activity Areas

Background: Miners and the people living close to mining sites are exposed to elevated levels of ionizing radiation with or without their knowledge. This study was designed to evaluate the outdoor background radiation levels in some selected mining locations and major activity areas of Ebonyi State, South-Eastern, Nigeria and their radiological impacts. Materials and Methods: The levels of background radiation in these mining areas were estimated using a well calibrated International Medicom CRM-100 Digital Radiation Monitor (survey meter). A cross-sectional survey was adopted for this study. Based on standard method, the radiation monitor was held at a distance of 1.0 meters above the ground and three readings taken at each location and the mean recorded. The radiation dose rates were calculated. A descriptive statistic and inferential statistic were used to summarize the data using statistical package for social Sciences SPSS version 21. Results: The mean dose rate for all the mining locations studied is 0.269+0.039(µSv/hr) and OAEDR of 0.470+0.068(mSv/yr). The excess life cancer risk for adult and children are 1.645 x 10-3 and 1.175 x 10-3 in the mining areas respectively. The mean outdoor Annual Equivalent Dose Rate (OAEDR) for the mining locations of Ebonyi States was 0.470±0.068 and mean of the radiation dose values recommended by UNSCEAR (2008) was 2.4± 0.48. There was statistically significance mean difference between the mean of OAEDR and the UNCEAR recommended value (p = 0.001). Conclusion: the outdoor background radiation levels emitted from the study area are within permissible limits for the general population. Therefore there is little risk of instantaneous radiation hazard within the mining areas of Ebonyi State. Key words: Absorb dose, excess life Cancer risk, radiation hazard.

scholarly journals On systematically building a controlled natural language for functional requirements

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Alvaro Veizaga ◽  
Mauricio Alferez ◽  
Damiano Torre ◽  
Mehrdad Sabetzadeh ◽  
Lionel Briand
Keyword(s):  
Information System ◽  
Natural Language ◽  
Qualitative Methodology ◽  
Case Study Research ◽  
Empirical Evaluation ◽  
Functional Requirements ◽  
Industrial Case Study ◽  
Requirements Specifications ◽  
Financial Domain

AbstractNatural language (NL) is pervasive in software requirements specifications (SRSs). However, despite its popularity and widespread use, NL is highly prone to quality issues such as vagueness, ambiguity, and incompleteness. Controlled natural languages (CNLs) have been proposed as a way to prevent quality problems in requirements documents, while maintaining the flexibility to write and communicate requirements in an intuitive and universally understood manner. In collaboration with an industrial partner from the financial domain, we systematically develop and evaluate a CNL, named Rimay, intended at helping analysts write functional requirements. We rely on Grounded Theory for building Rimay and follow well-known guidelines for conducting and reporting industrial case study research. Our main contributions are: (1) a qualitative methodology to systematically define a CNL for functional requirements; this methodology is intended to be general for use across information-system domains, (2) a CNL grammar to represent functional requirements; this grammar is derived from our experience in the financial domain, but should be applicable, possibly with adaptations, to other information-system domains, and (3) an empirical evaluation of our CNL (Rimay) through an industrial case study. Our contributions draw on 15 representative SRSs, collectively containing 3215 NL requirements statements from the financial domain. Our evaluation shows that Rimay is expressive enough to capture, on average, 88% (405 out of 460) of the NL requirements statements in four previously unseen SRSs from the financial domain.

scholarly journals Radiation Awareness for Endovascular Abdominal Aortic Aneurysm Repair in the Hybrid Operating Room: An Instant Operator Risk Chart for Daily Practice

2021 ◽  
pp. 152660282110074
Author(s):  
Quirina M. B. de Ruiter ◽  
Frans L. Moll ◽  
Constantijn E. V. B. Hazenberg ◽  
Joost A. van Herwaarden
Keyword(s):  
Radiation Dose ◽  
Dose Rate ◽  
Effect Size ◽  
Radiation Risk ◽  
Dose Limit ◽  
Access Site ◽  
Femoral Access ◽  
Dose Rates ◽  
Rate Prediction ◽  
Operator Dose

Introduction: While the operator radiation dose rates are correlated to patient radiation dose rates, discrepancies may exist in the effect size of each individual radiation dose predictors. An operator dose rate prediction model was developed, compared with the patient dose rate prediction model, and converted to an instant operator risk chart. Materials and Methods: The radiation dose rates (DRoperator for the operator and DRpatient for the patient) from 12,865 abdomen X-ray acquisitions were selected from 50 unique patients undergoing standard or complex endovascular aortic repair (EVAR) in the hybrid operating room with a fixed C-arm. The radiation dose rates were analyzed using a log-linear multivariable mixed model (with the patient as the random effect) and incorporated varying (patient and C-arm) radiation dose predictors combined with the vascular access site. The operator dose rate models were used to predict the expected radiation exposure duration until an operator may be at risk to reach the 20 mSv year dose limit. The dose rate prediction models were translated into an instant operator radiation risk chart. Results: In the multivariate patient and operator fluoroscopy dose rate models, lower DRoperator than DRpatient effect size was found for radiation protocol (2.06 for patient vs 1.4 for operator changing from low to medium protocol) and C-arm angulation. Comparable effect sizes for both DRoperator and DRpatient were found for body mass index (1.25 for patient and 1.27 for the operator) and irradiated field. A higher effect size for the DRoperator than DRpatient was found for C-arm rotation (1.24 for the patient vs 1.69 for the operator) and exchanging from femoral access site to brachial access (1.05 for patient vs 2.5 for the operator). Operators may reach their yearly 20 mSv year dose limit after 941 minutes from the femoral access vs 358 minutes of digital subtraction angiography radiation from the brachial access. Conclusion: The operator dose rates were correlated to patient dose rate; however, C-arm angulation and changing from femoral to brachial vascular access site may disproportionally increase the operator radiation risk compared with the patient radiation risk. An instant risk chart may improve operator dose awareness during EVAR.

Radioactive Excretion in Human Milk Following Administration of Technetium Tc 99m Macroaggregated Albumin

PEDIATRICS ◽  
1982 ◽  
Vol 70 (2) ◽  
pp. 231-234
Author(s):  
W. B. Pittard ◽  
R. Merkatz ◽  
B. D. Fletcher
Keyword(s):  
Nuclear Medicine ◽  
Breast Milk ◽  
Human Serum Albumin ◽  
Radiation Dose ◽  
Human Milk ◽  
Radiation Hazard ◽  
Base Line ◽  
Pulmonary Emboli ◽  
Lung Scan ◽  
Total Body

Albumin-tagged sodium pertechnetate (technetium) is routinely used in nuclear medicine for scanning procedures of the lung. The rate of excretion of this radionuclide into breast milk and the resultant potential radiation hazard to the nursing infant have received little attention. Therefore the milk from a nursing mother who required a lung scan because of suspected pulmonary emboli using an intravenous injection of 4 mCi of technetium Tc 99 macroaggregated human serum albumin was monitored. Albumin tagging severely limited the entrance of technetium into her milk and the radio-activity of the milk returned to base line by 24 hours. A total of 2.02 µCi of technetium was measured in the 24-hour milk collection after technetium injection and 94% of this amount was excreted by 15.5 hours. This amount of technetium administered orally to a newborn would deliver a total body radiation dose of .3 mrad. Therefore, an infant would receive trivial doses of radiation if breast-feeding were resumed 15.5 hours after administration of the radionuclide to the mother and nursing can clearly be resumed safely 24 hours after injection.

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