نتایج جستجو برای: kerma

تعداد نتایج: 466  

2007
J. Cardoso L. Santos C. Oliveira

The primary standard for air kerma for the gamma radiation of Cs-137, of the Metrological Laboratory of Ionising Radiation (LMRI), is an ionisation chamber of the type CC01. This instrument was, for the first time, used to characterize the radiation field, in terms of air kerma, produced by a Cs-137 source in an irradiator Shepherd model 81, used mainly for radiation protection calibration purp...

2011
J Urairat S Asavaphatiboon S Singhara Na Ayuthaya N Pongnapang

PURPOSE This study was carried out to assess the radiation dose to patients undergoing interventional radiology procedures at Ramathibodi Hospital, Bangkok, Thailand. METHODS Data were collected from 60 patients under transarterial oily-chemoembolisation (TOCE) and femoral angiography performed with the Toshiba Infinix model VC-i FPD single plane system. Data were also collected from 60 patie...

A. Bozkurt, G. Kemikler, H. Acun,

Background: This study aims to calculate the air-kerma strength (SK), the dose rate constant (∧) and the dose rate profiles of a Gammamed 12i Ir-192 source by using the Monte Carlo technique and to compare the dose rate values with those calculated by the Abacus HDR treatment planning system (TPS). Materials and Methods: Air-kerma strength (in units of U; 1 U= μGy m2 h-1) and the dose ra...

2003
Stephen M. Seltzer Paul J. Lamperti Robert Loevinger Michael G. Mitch James T. Weaver Bert M. Coursey

The new U.S. measurement standard for the air-kerma strength from low-energy photon-emitting brachytherapy seed sources is formally described in detail. This instrument-based standard was implemented on 1 January 1999, with its salient features and the implications of differences with the previous standard given only through a series of informal communications. The Wide-Angle Free-Air Chamber (...

Journal: :The Review of scientific instruments 2014
J-E Groetz N Ounoughi C Mavon A Belafrites M Fromm

We report the design of a millimeter-sized parallel plate free-air ionization chamber (IC) aimed at determining the absolute air kerma rate of an ultra-soft X-ray beam (E = 1.5 keV). The size of the IC was determined so that the measurement volume satisfies the condition of charged-particle equilibrium. The correction factors necessary to properly measure the absolute kerma using the IC have be...

Journal: :Physics in medicine and biology 2008
R Kramer H J Khoury J W Vieira

CALDose_X is a software tool that provides the possibility of calculating incident air kerma (INAK) and entrance surface air kerma (ESAK), two important quantities used in x-ray diagnosis, based on the output of the x-ray equipment. Additionally, the software uses conversion coefficients (CCs) to assess the absorbed dose to organs and tissues of the human body, the effective dose as well as the...

Journal: :Medical physics 2007
J P McCaffrey H Shen B Downton E Mainegra-Hing

The attenuating properties of several types of lead (Pb)-based and non-Pb radiation shielding materials were studied and a correlation was made of radiation attenuation, materials properties, calculated spectra and ambient dose equivalent. Utilizing the well-characterized x-ray and gamma ray beams at the National Research Council of Canada, air kerma measurements were used to compare a variety ...

Journal: :Dotawo 2023

A research programme conducted by the Swiss archaeological mission in oldest sectors of Eastern Cemetery Kerma has uncovered tombs several dozen archers. The appearance these armed warriors dating from ca. 2300 BC onwards can be put parallel with resumption commercial activities between Egypt and Nubia, illustrated Harkhuf expeditions. archers their warrior attributes probably participate emerg...

2016
Kevin A. Wunderle Joseph T. Rakowski Frank F. Dong

Modern fluoroscopes used for image-based guidance in interventional procedures are complex X-ray machines, with advanced image acquisition and processing systems capable of automatically controlling numerous parameters based on defined protocol settings. This study evaluated and compared approaches to technique factor modulation and air kerma rates in response to simulated patient thickness var...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید