Modeling and Experimental Study of Inorganic Crystal Response Function for Gamma Spectroscopy and Dosimetry

Author(s):  
Muhammad Ali ◽  
Nafisah Khan ◽  
Ahmed Hosny ◽  
Rachid Machrafi

A gamma spectrometer based on LaBr3(Ce) crystal has been developed. The spectrometer uses a compact data acquisition system including a multi-channel analyzer and corresponding electronics components. The response function of the detector has been simulated using Monte Carlo Code (MCNPX 2.7E). It has been also tested, at the University of Ontario Institute of Technology radiation facilities, using a series of gamma radiation sources. The simulated data has been compared with experiments and a good agreement has been achieved. This paper presents the parameters of the developed spectrometer and the results of its testing along with a comparison with NaI(TI) crystal.

1974 ◽  
Vol 5 (1) ◽  
pp. 32-49 ◽  
Author(s):  
JOHN TVEIT

This article deals with the problem of insulating measuring weirs to avoid ice disturbances. The development of a simple method for insulating a conventional V-weir is described. This method will serve its purpose in many cases. For more difficult cases a special type of a fully insulated weir is described. The experiments described were carried out by The Division of Hydraulic Engineering, The University of Trondheim, The Norwegian Institute of Technology, at the River and Harbour Laboratory of the University, and at the IHD representative basin Sagelva.


2021 ◽  
Vol 13 (13) ◽  
pp. 7174
Author(s):  
Massimo Rundo ◽  
Paolo Casoli ◽  
Antonio Lettini

In hydraulic components, nonlinearities are responsible for critical behaviors that make it difficult to realize a reliable mathematical model for numerical simulation. With particular reference to hydraulic spool valves, the viscous friction coefficient between the sliding and the fixed body is an unknown parameter that is normally set a posteriori in order to obtain a good agreement with the experimental data. In this paper, two different methodologies to characterize experimentally the viscous friction coefficient in a hydraulic component with spool are presented. The two approaches are significantly different and are both based on experimental tests; they were developed in two distinct laboratories in different periods of time and applied to the same flow compensator of a pump displacement control. One of the procedures was carried out at the Fluid Power Research Laboratory of the Politecnico di Torino, while the other approach was developed at the University of Parma. Both the proposed methods reached similar outcomes; moreover, neither method requires the installation of a spool displacement transducer that can significantly affect the results.


Radiocarbon ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 325-330 ◽  
Author(s):  
K D Macario ◽  
P R S Gomes ◽  
R M Anjos ◽  
C Carvalho ◽  
R Linares ◽  
...  

After 22 yr of the low-level liquid scintillation counting 14C laboratory at the Center for Nuclear Energy in Agriculture (CENA) at São Paulo University (USP), Piracicaba, Brazil, and several collaborative projects with Brazilian and international researchers from distinct scientific areas, the first 14C accelerator mass spectrometry (AMS) laboratory in Latin America was installed at the Physics Institute of the Universidade Federal Fluminense (UFF), Niterói, Brazil. A 250kV single stage accelerator produced by National Electrostatics Corporation began its operation in 2012. In this work, we compare measurements performed at the AMS Radiocarbon Laboratory at UFF (LAC-UFF) with those performed at CENA and the University of Georgia (UGAMS), Georgia, USA. All the results obtained from distinct inorganic and organic samples were in very good agreement.


2021 ◽  
Author(s):  
Emily J. King ◽  
Natalie N. Viscariello ◽  
Larry A. DeWerd

This work seeks to develop standard X-ray beams that are matched to radiobiology X-ray irradiators. The calibration of detectors used for dose determination of these irradiators is performed with a set of standard X rays that are more heavily filtered and/or lower energy, which leads to a higher uncertainty in the dose measurement. Models of the XRad320, SARRP, and the X-ray tube at the University of Wisconsin Medical Radiation Research Center (UWMRRC) were created using the BEAMnrc user code of the EGSnrc Monte Carlo code system. These models were validated against measurements, and the resultant modeled spectra were used to determine the amount of added filtration needed to match the X-ray beams at the UWMRRC to those of the XRad320 and SARRP. The depth profiles and half-value layer (HVL) simulations performed using BEAMnrc agreed to measurements within 3% and 3.6%, respectively. A primary measurement device, a free-air chamber, was developed to measure air kerma in the medium energy range of X rays. The resultant spectra of the matched beams had HVL's that matched the HVL's of the radiobiology irradiators well within the 3% criteria recommended by the International Atomic Energy Agency (IAEA) and the average energies agreed within 2.4%. In conclusion, three standard X-ray beams were developed at the UWMRRC with spectra that more closely match the spectra of the XRad320 and SARRP radiobiology irradiators, which will aid in a more accurate dose determination during calibration of these irradiators.


2021 ◽  
Author(s):  
Roger Few ◽  
Mythili Madhavan ◽  
Narayanan N.C. ◽  
Kaniska Singh ◽  
Hazel Marsh ◽  
...  

This document is an output from the “Voices After Disaster: narratives and representation following the Kerala floods of August 2018” project supported by the University of East Anglia (UEA)’s GCRF QR funds. The project is carried out by researchers at UEA, the Indian Institute for Human Settlements (IIHS), the Indian Institute of Technology (IIT), Bombay, and Canalpy, Kerala. In this briefing, we provide an overview of some of the emerging narratives of recovery in Kerala and discuss their significance for post-disaster recovery policy and practice. A key part of the work was a review of reported recovery activities by government and NGOs, as well as accounts and reports of the disaster and subsequent activities in the media and other information sources. This was complemented by fieldwork on the ground in two districts, in which the teams conducted a total of 105 interviews and group discussions with a range of community members and other local stakeholders. We worked in Alleppey district, in the low-lying Kuttanad region, where extreme accumulation of floodwaters had been far in excess of the normal seasonal levels, and in Wayanad district, in the Western Ghats, where there had been a concentration of severe flash floods and landslides.


2010 ◽  
Vol 88 (8) ◽  
pp. 575-584 ◽  
Author(s):  
M. K. Ghosh ◽  
P. K. Haldar ◽  
S. K. Manna ◽  
A. Mukhopadhyay ◽  
G. Singh

In this paper we present some results on the nonstatistical fluctuation in the 1-dimensional (1-d) density distribution of singly charged produced particles in the framework of the intermittency phenomenon. A set of nuclear emulsion data on 16O-Ag/Br interactions at an incident momentum of 200A GeV/c, was analyzed in terms of different statistical methods that are related to the self-similar fractal properties of the particle density function. A comparison of the present experiment with a similar experiment induced by the 32S nuclei and also with a set of results simulated by the Lund Monte Carlo code FRITIOF is presented. A similar comparison between this experiment and a pseudo-random number generated simulated data set is also made. The analysis reveals the presence of a weak intermittency in the 1-d phase space distribution of the produced particles. The results also indicate the occurrence of a nonthermal phase transition during emission of final-state hadrons. Our results on factorial correlators suggests that short-range correlations are present in the angular distribution of charged hadrons, whereas those on oscillatory moments show that such correlations are not restricted only to a few particles. In almost all cases, the simulated results fail to replicate their experimental counterparts.


1960 ◽  
Vol 33 (5) ◽  
pp. 1323-1374 ◽  
Author(s):  
C. L. Weidner ◽  
G. J. Crocker

Abstract An increasing number of papers in the field of adhesion have been appearing in Rubber Chemistry & Technology. In the period 1941–1950 twenty-two papers appeared in this Journal covering various aspects of adhesion, whereas in the year 1959 alone eleven papers appear. The Rubber Division Library at the University of Akron has compiled bibliographies as follows: Bibliography # 10, “Use of Synthetic Resins in Natural and Synthetic Rubbers”, covering the period 1930–1952; Bibliography # 18, “Rubber to Metal Bonding”, in two parts, one covering the period 1937–1954 and a supplement covering 1955–1958; and Bibliography #20, “Reclaim Rubber Cements”, covering the period 1927–1954. In addition, special bibliographies were prepared covering the period 1949–1958 on the subjects “Rubber to Wood Adhesives”, “Rubber to Fabric Adhesives”, “Bonding of Polyurethanes”, “Metal to Metal Adhesives”, and “Chemistry of Rubber Adhesives”. The most comprehensive text in the field is “Adhesion and Adhesives” edited by N. A. DeBruyne and R. Houwink. More limited in scope are “Adhesive Bonding of Metals” by Epstein, “Adhesives for Wood” by Knight, “Adhesive Bonding of Reinforced Plastics” by Perry. Also “Rubber to Metal Bonding” by Buchan, which stresses the brass plating technic. Skeist has recently edited a “Handbook of Adhesives”. The Encyclopedia of Chemical Technology contains articles on “Adhesives” in Volume I and the First Supplement Volume. Various symposia have been sources of worthwhile papers on adhesion. The Division of Paint, Plastics, and Printing Ink Chemistry, ACS, published such papers in their preprint booklets, volume XV, No. 1 (1955) and volume XX, No. 1 (1960). Papers given at this division's “Recent Advances in Adhesives” symposium in 1957 are also published. Publication of papers at two symposia held in 1952 (Society of The Chemical Industry, London; Case Institute of Technology, Cleveland) form a valuable collection. Papers from The Second International Congress of Surface Activity in London in 1957 are also published. Papers from a Symposium on Adhesion held by the Society of Rheology in 1959 are published in volume IV of the Society's Transactions. General review articles on adhesion with extensive bibliographies were published as follows : Rinker-Kline “Survey of Adhesives and Adhesion; Kline-Reinhart “Fundamentals of Adhesion”; Brantley-Charnell “Investigation of the Nature of Forces of Adhesion”; Reinhart-Callomon “Survey of Adhesion and Adhesives” and Rutzler “Types of Bonds Involved in Adhesion”. The Reinhart-Callomon survey is quite extensive in its bibliography.


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