CAN A TC-99M FILL TYPE FLOOD SOURCE MATCH THE PERFORMANCE OF A COMMERCIALLY MANUFACTURED CO-57 SEALED SOURCE?

1995 ◽  
Vol 20 (7) ◽  
pp. 657
Author(s):  
K Arndt ◽  
D Bosc ◽  
J Vilani
Keyword(s):  
2021 ◽  
Author(s):  
Amrie Singh ◽  
David Dawson ◽  
Mark Trigg ◽  
Nigel Wright

AbstractFlooding is an important global hazard that causes an average annual loss of over 40 billion USD and affects a population of over 250 million globally. The complex process of flooding depends on spatial and temporal factors such as weather patterns, topography, and geomorphology. In urban environments where the landscape is ever-changing, spatial factors such as ground cover, green spaces, and drainage systems have a significant impact. Understanding source areas that have a major impact on flooding is, therefore, crucial for strategic flood risk management (FRM). Although flood source area (FSA) identification is not a new concept, its application is only recently being applied in flood modelling research. Continuous improvements in the technology and methodology related to flood models have enabled this research to move beyond traditional methods, such that, in recent years, modelling projects have looked beyond affected areas and recognised the need to address flooding at its source, to study its influence on overall flood risk. These modelling approaches are emerging in the field of FRM and propose innovative methodologies for flood risk mitigation and design implementation; however, they are relatively under-examined. In this paper, we present a review of the modelling approaches currently used to identify FSAs, i.e. unit flood response (UFR) and adaptation-driven approaches (ADA). We highlight their potential for use in adaptive decision making and outline the key challenges for the adoption of such approaches in FRM practises.


2019 ◽  
Vol 61 (6) ◽  
pp. 741-747
Author(s):  
M. Mostafa ◽  
M. A. Tawfic ◽  
M. A. El-Absy ◽  
H. E. Ramadan ◽  
S. A. Sadeek
Keyword(s):  

2020 ◽  
Vol 51 (3) ◽  
pp. 423-442
Author(s):  
Naser Dehghanian ◽  
S. Saeid Mousavi Nadoushani ◽  
Bahram Saghafian ◽  
Morteza Rayati Damavandi

Abstract An important step in flood control planning is identification of flood source areas (FSAs). This study presents a methodology for identifying FSAs. Unit flood response (UFR) approach has been proposed to quantify FSAs at subwatershed and/or cell scale. In this study, a distributed ModClark model linked with Muskingum flow routing was used for hydrological simulations. Furthermore, a fuzzy hybrid clustering method was adopted to identify hydrological homogenous regions (HHRs) resulting in clusters involving the most effective variables in runoff generation as selected through factor analysis (FA). The selected variables along with 50-year rainfall were entered into an artificial neural network (ANN) model optimized via genetic algorithm (GA) to predict flood index (FI) at cell scale. The case studies were two semi-arid watersheds, Tangrah in northeastern Iran and Walnut Gulch Experimental Watershed in Arizona. The results revealed that the predicted values of FI via ANN-GA were slightly different from those derived via UFR in terms of mean squared error (MSE), mean absolute error (MAE), and relative error (RE). Also, the prioritized FSAs via ANN-GA were almost similar to those of UFR. The proposed methodology may be applicable in prioritization of HHRs with respect to flood generation in ungauged semi-arid watersheds.


2004 ◽  
Vol 71 (1-2) ◽  
pp. 577-580 ◽  
Author(s):  
E.S Martell
Keyword(s):  

2014 ◽  
Vol 41 (11) ◽  
pp. 112502 ◽  
Author(s):  
Frank P. DiFilippo
Keyword(s):  

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 273 ◽  
Author(s):  
Fatemeh Fadia Maghsood ◽  
Hamidreza Moradi ◽  
Ali Reza Massah Bavani ◽  
Mostafa Panahi ◽  
Ronny Berndtsson ◽  
...  

This study assessed the impact of climate change on flood frequency and flood source area at basin scale considering Coupled Model Intercomparison Project phase 5 General Circulation Models (CMIP5 GCMs) under two Representative Concentration Pathways (RCP) scenarios (2.6 and 8.5). For this purpose, the Soil and Water Assessment Tool (SWAT) hydrological model was calibrated and validated for the Talar River Basin in northern Iran. Four empirical approaches including the Sangal, Fill–Steiner, Fuller, and Slope-based methods were used to estimate the Instantaneous Peak Flow (IPF) on a daily basis. The calibrated SWAT model was run under the two RCP scenarios using a combination of twenty GCMs from CMIP5 for the near future (2020–40). To assess the impact of climate change on flood frequency pattern and to quantify the contribution of each subbasin on the total discharge from the Talar River Basin, Flood Frequency Index (FFI) and Subbasin Flood Source Area Index (SFSAI) were used. Results revealed that the projected climate change will likely lead to an average discharge decrease in January, February, and March for both RCPs and an increase in September and October for RCP 8.5. The maximum and minimum temperature will likely increase for all months in the near future. The annual precipitation could increase by more than 20% in the near future. This is likely to lead to an increase of IPF. The results can help managers and policy makers to better define mitigation and adaptation strategies for basins in similar climates.


2015 ◽  
Vol 17 (1) ◽  
pp. 67-74
Author(s):  
Md Fakhar Uddin ◽  
SM Moinul Islam ◽  
M Nasim Khan ◽  
Ratan Kumar Chakraborty ◽  
Shakila Zaman Rima ◽  
...  

The main quality controls of hybrid SPECT/CT are Uniformity and Multiple Head Registration (MHR)/Centre of rotation (COR). Uniformity corrects and verifies camera’s response to uniform distribution of radionuclides on the detector surface. MHR/COR not only observes mechanical errors but also quantitatively corrects the errors due to movement of patients and detectors onthe SPECT images. The aim of the study is to establish baseline values thatcan be used as reference for future quality assurance and to verify the manufacturer’s specification. Both intrinsic and extrinsic Uniformity were measured by using 18?Ci 99mTc point source and 35mCi 99mTc flood source respectively. For MHR/COR measurements, MHR Phantom containing five approximately equal strength (1 mCi99mTc of each) point sourceswere used. The values were found to be in correlation with manufacturer’s specification. DOI: http://dx.doi.org/10.3329/bjnm.v17i1.22494 Bangladesh J. Nuclear Med. 17(1): 67-74, January 2014


Sign in / Sign up

Export Citation Format

Share Document