نتایج جستجو برای: ray output

تعداد نتایج: 484816  

A novel ultra-high compliance, low power, very accurate and high output impedance current output stage (COS) with extremely high output current drive capability is proposed in this paper. The principle of operation of this unique structure is discussed, its most important formulas are derived and its outstanding performance is verified by HSPICE simulation in TSMC 0.18µm CMOS, BSIM3, and Level4...

Behzad Mohsenzadeh Mohammad Reza Deevband,

Introduction: Paediatric patients deserve special attention because of the higher radiation risks compared with adults. The main purpose of this study is to determine patient dose and diagnostic reference level for Paediatric through Entrance Surface Dose (ESD) calculations in common X-ray examination and to establish Paediatric national DRLs in digital radiography in Iran. <...

Journal: :Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics 2016
Mayuresh Kulkarni Ronald Dendere Fred Nicolls Stef Steiner Tania S Douglas

We present a method for simulating slot-scanning X-ray imaging using the general-purpose Monte Carlo simulation package PENELOPE and penEasy Imaging. Different phantoms can be defined with the PENGEOM package, which defines bodies as combinations of volumes limited by quadric surfaces. The source-detector geometry, the position of the object, the collimator, the X-ray tube properties, the detec...

1998
R. Shaw J. C. Hsu

We describe calstis2, the calstis calibration module which combines CRSPLIT and repeated exposures to produce a single, cosmic ray rejected image. Cosmic ray rejection in the STIS pipeline employs a noise model and parameterized rejection criteria to identify and exclude discrepant values in forming the output image. The calstis pipeline is able to perform this cosmic ray rejection because the ...

1998
Stefi Baum J. C. Hsu Harry Ferguson

In this ISR we describe calstis-2, the calstis calibration module which combines CRSPLIT exposures to produce a single cosmic ray rejected image. Cosmic ray rejection in the STIS pipeline will follow the same basic philosophy as does the STSDAS task crrej a series of separate CRSPLIT exposures are combined to produce a single summed image, where discrepant (different by some number of sigma fro...

Journal: :Journal of nuclear medicine technology 2004
J Anthony Seibert

The purpose is to review in a 4-part series: (i) the basic principles of x-ray production, (ii) x-ray interactions and data capture/conversion, (iii) acquisition/creation of the CT image, and (iv) operational details of a modern multislice CT scanner integrated with a PET scanner. Advances in PET technology have lead to widespread applications in diagnostic imaging and oncologic staging of dise...

1999
GREG M. MADEJSKI

This paper summarizes the observations which provide the best evidence for the presence of black holes in active galactic nuclei. This includes: X–ray variability; kinematical studies using optical emission lines as well as the distribution of megamaser spots; and the shape of the Fe Kα X–ray emission line. It also presents the current status of our understanding of jetdominated active galaxies...

2008
Louis Edward Fernandes Edward Fernandes Chandrasekhar Ramanathan

We investigate the use of an Amptek Cool-X X-ray Generator for an instructional tool in the physics of x-rays, as well as a source for x-rays for crystal diffraction experiments. The x-ray source is a solid-state two-phase air-cooled source with a timevarying photon output. Two detectors are used in this experiment, the first being an Amptek X-123 Spectrometer and the second a combination scint...

2004
J. Anthony Seibert

The purpose is to review in a 4-part series: (i) the basic principles of x-ray production, (ii) x-ray interactions and data capture/conversion, (iii) acquisition/creation of the CT image, and (iv) operational details of a modern multislice CT scanner integrated with a PET scanner. Advances in PET technology have lead to widespread applications in diagnostic imaging and oncologic staging of dise...

A. Shabestani Monfared, A.R. Shirazi, H. Babapour, T. Allahverdi Pourfallah,

Background: Making use of the orthovoltage machines in Radiotherapy, is one of the routine methods for the treatment of the superficial lesions. In this study, an important determinant of X-ray quality, the HVL (Half Value Layer), has been evaluated. Materials and Methods: The HVLs of a orthovoltage X-ray machine in 120 and 180 kVp are measured, using an empirical method, in which the HVLs are ...

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