scholarly journals Measurement of Uniformity and Multiple Head Registration (MHR)/Centre of Rotation (COR) of a Newly Installed Hybrid SPECT/CT At INMAS, Mymensingh

2015 ◽  
Vol 17 (1) ◽  
pp. 67-74
Author(s):  
Md Fakhar Uddin ◽  
SM Moinul Islam ◽  
M Nasim Khan ◽  
Ratan Kumar Chakraborty ◽  
Shakila Zaman Rima ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Point Source ◽  
Uniform Distribution ◽  
Quality Controls ◽  
Equal Strength ◽  
Detector Surface ◽  
Baseline Values ◽  
Centre Of Rotation ◽  
Flood Source ◽  
Spect Images

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

scholarly journals Composite elastomeric materials filled with modified mineral fillers

2021 ◽  
Vol 264 ◽  
pp. 05006
Author(s):  
Ahmadjon Ibadullayev ◽  
Elmira Teshabayeva ◽  
Bakhadir Kakharov ◽  
Dilnoza Nigmatova
Keyword(s):  
Uniform Distribution ◽  
Mineral Filler ◽  
Equal Strength ◽  
Elastomeric Materials ◽  
Adsorbed Sulfur ◽  
Technical Properties ◽  
Mineral Fillers ◽  
Butadiene Styrene

In the paper, the influence of modified Angren kaolin on the properties of composite elastomeric materials based on butadiene-styrene rubber has been established that the addition of modified Angren kaolin into rubber mixtures instead of gas pedals, activators and mineral fillers causes intensive connection of sulfur with macromolecules. Adsorbed sulfur on the surface of particles of modified Angren kaolin and its uniform distribution in the composition and formation of the structure with equal force were determined. This effect shows that the modified Angren kaolin in the curing processes accelerates and activates and affects the formation of the curing grid with equal strength and helps distribution throughout the composite. It has been established that introduction of MAK into the composition of elastomers more than 50 wt. % per 100 wt. % of rubber changes technological and technical properties of composite elastomeric materials. The application of modified Angren kaolin instead of the gas pedal, activator of vulcanization and mineral filler in composite elastomeric materials allows making rubber goods of various purposes.

Quality controls for CBCT devices: The efomp guideline for quality assurance of images and dose

2016 ◽  
Vol 32 ◽  
pp. 280-281 ◽  
Author(s):  
H. las Heras ◽  
O. Rampado ◽  
J. Andersson ◽  
I. Hernandez Giron ◽  
M. Nilsson ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Quality Controls

Defining the Critical Phase

1984 ◽  
Vol 3 (6) ◽  
pp. 377-380
Author(s):  
R. S. DeWoskin ◽  
B. M. Sadler
Keyword(s):  
Quality Assurance ◽  
Reference Standards ◽  
Quality Assurance Program ◽  
Specific Reference ◽  
Quality Controls ◽  
Critical Phase ◽  
Mean Compliance ◽  
Principal Researcher ◽  
Intended Use

Quality does not mean compliance with a checklist of standards but rather “fitness for use.” Compliance with a checklist of standards will only assure quality if the standards specifically address the intended use of the final results. In the design of a quality assurance program, the emphasis is upon quality controls and monitoring schedules for those aspects of the study that significantly alter the variability of the final results and alter the variability to the extent that the final results are no longer useful. Therefore, the principal researcher in conjunction with the quality assurance staff contribute to the quality of a study by applying combined expertise in the design of specific reference standards that both address the fitness for use criterion and the more comprehensive government standards.

scholarly journals Earth Observation for Citizen Science Validation, or, Citizen Science for Earth Observation Validation? The Role of Quality Assurance of Volunteered Observations

2017 ◽  
Author(s):  
Didier Leibovici ◽  
Jamie Williams ◽  
Julian Rosser ◽  
Crona Hodges ◽  
Colin Chapman ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Citizen Science ◽  
Open Data ◽  
Secondary Data ◽  
Earth Observation ◽  
Japanese Knotweed ◽  
Fallopia Japonica ◽  
Quality Controls ◽  
Assurance Process

Environmental policy involving citizen science (CS) is of growing interest. In support of this open data stream, validation or quality assessment of the CS data and their appropriate usage for evidence-based policy making, needs a flexible and easily adaptable data curation process ensuring transparency. Addressing these needs, this paper describes an approach for automatic quality assurance as proposed by the Citizen OBservatory WEB (COBWEB) FP7 project. This approach is based upon a workflow composition that combines different quality controls, each belonging to seven categories or ‘pillars’. Each pillar focuses on a specific dimension in the types of reasoning algorithms for CS data qualification. These pillars attribute values to a range of quality elements belonging to three complementary quality models. Additional data from various sources, such as Earth Observation (EO) data, are often included as part of the inputs of quality controls within the pillars. However, qualified CS data can also contribute to the validation of EO data. Therefore, the question of validation can be considered as ‘two sides of the same coin’. Based on an invasive species CS study, concerning Fallopia japonica (Japanese knotweed), the paper discusses the flexibility and usefulness of qualifying CS data, either when using an EO data for the validation within the quality assurance process, or validating an EO data product that describes the risk of occurrence of the plant. Both validation paths are found to be improved by quality assurance of the CS data. Addressing the reliability of CS open data, issues and limitations of the role of quality assurance for validation, due to the quality of secondary data used within the automatic workflow, are described, e.g. error propagation, paving the route to improvements in the approach.

Experimental Investigation on Road Marking Distress Evolution: Beyond Testing, Quality Assurance and Maintenance Improvement

2013 ◽  
Vol 723 ◽  
pp. 846-853 ◽  
Author(s):  
Marco Pasetto ◽  
Stefano Damiano Barbati
Keyword(s):  
Experimental Investigation ◽  
Quality Assurance ◽  
Maintenance Management ◽  
Skid Resistance ◽  
Quality Controls ◽  
The Road ◽  
Road Pavement ◽  
Road Marking ◽  
Sprayed Coatings

Road markings should always be visible, readable and effective. Their performance is related to the quality of materials, their application and textural characteristics of the road pavement. The evolution of properties (visibility, skid resistance, color and durability) also depends on the product, its resistance to traffic abrasion, the application technique and adhesion between coating and substrate. This paper analyzes the results of a wide campaign of tests (over more than 4,000 km of lines) on road marking performances, with the purpose of evaluating a model for design and maintenance management. Mainly post-sprayed coatings are investigated with regard to quality controls, their frequency and protocols, according to the standards in force.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

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