Abstract:
:Flows in lung bifurcations are complicated by geometry, and it is recognized that accurate lung dosimetric models require realistic calculations of the flow and particle deposition patterns. A computational fluid dynamics study of flow and particle concentration has been carried out for a lung bifurcation based on the model developed by Weibel. The predicted flow patterns match well with previously reported experimental data. Secondary flow patterns and locations close to the walls having high particle concentrations are clearly seen.
journal_name
Health Physjournal_title
Health physicsauthors
Kinsara AA,Tompson RV,Loyalka SKdoi
10.1097/00004032-199301000-00002subject
Has Abstractpub_date
1993-01-01 00:00:00pages
13-22issue
1eissn
0017-9078issn
1538-5159journal_volume
64pub_type
杂志文章相关文献
HEALTH PHYSICS文献大全abstract::The use of nuclear gauges for process control and elemental analysis in the mining industry in Ghana, West Africa, is wide spread and on the increase in recent times. The Ghana Radiation Protection Board regulates nuclear gauges through a system of notification and authorization by registration or licensing, inspectio...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0b013e3181cd7c6f
更新日期:2010-05-01 00:00:00
abstract::Measurements of the effective diffusion coefficient, De, of 222Rn in concrete are important for accurate determination of transport mechanisms and computer modeling of radon entry into structures. A method for in-situ determination of De as well as the emanation fraction, F, is described. It is based on continuous mea...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199506000-00008
更新日期:1995-06-01 00:00:00
abstract::Measurements of radon at 50 sites with varying geology indicate that outdoor air in Nevada is comparable to that measured nationwide by Hopper et al. (1991). The statewide median of 15 Bq m-3 (0.4 pCi L-1) is essentially the same as the nationwide median. The range is considerable: from 2.6-52 Bq m-3 (0.07-1.40 pCi L-...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199404000-00009
更新日期:1994-04-01 00:00:00
abstract::Databases are being created that contain verified and updated dosimetry and worker history information for workers at the Mayak Production Association. Many workers had significant external and internal exposures, particularly during the early years (1948-1952) of operation. These dosimetric and worker history data ar...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-200007000-00012
更新日期:2000-07-01 00:00:00
abstract::In this statement, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) presents its principles for protection against adverse health effects from exposure to non-ionizing radiation. These are based upon the principles for protection against ionizing radiation of the International Commission for ...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0000000000001252
更新日期:2020-05-01 00:00:00
abstract::The Brookhaven National Laboratory Sigma Pile is a radium-beryllium neutron source imbedded in a cube of graphite blocks. The pile is approximately 2.13 m on four sides and is 3.07 m high. Thermoluminescent dosimeters were used to determine the neutron and gamma-ray dose rates in the pile. Gamma-ray dose rate measurem...
journal_title:Health physics
pub_type: 杂志文章
doi:
更新日期:2004-05-01 00:00:00
abstract::Comparatively little research has been published on radioactive contamination from nuclear medicine patients using hospital toilet facilities. The present study was undertaken to obtain an estimate of the amount of restroom contamination found in a typical 700-bed community hospital as a result of nuclear medicine pro...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199205000-00015
更新日期:1992-05-01 00:00:00
abstract::The yield of chromosome aberrations (dicentric and ring chromosomes) was determined for five patients who had been extensively exposed to diagnostic x rays. Remarkably high aberration yields were obtained for each of them leading to correspondingly high equivalent whole body doses ("biological dosimetry"). The contrib...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199502000-00012
更新日期:1995-02-01 00:00:00
abstract::Prompt gamma emission data from the International Atomic Energy Agency's Prompt Gamma-ray Neutron Activation Analysis database are analyzed to determine the absorbed dose rates in tissue to be expected when natural elements are exposed in a near-thermal neutron environment. ...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0000000000000288
更新日期:2015-10-01 00:00:00
abstract::Medical health physics is the profession dedicated to the protection of healthcare providers, members of the public, and patients from unwarranted radiation exposure. Medical health physicists must be knowledgeable in the principles of health physics and in the applications of radiation in medicine. Advances in medica...
journal_title:Health physics
pub_type: 杂志文章,评审
doi:10.1097/00004032-200405000-00001
更新日期:2004-05-01 00:00:00
abstract::Haemopoietic stem cell assays allow investigation of local radiation damage at any time after contamination. These techniques were used to determine the relative effectiveness of 241Am and 226Ra in inducing damage in various cortical and trabecular bone marrow sites. Male Balb/c mice were injected with either 230 or 6...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198306001-00054
更新日期:1983-01-01 00:00:00
abstract::Experience gained during a field training exercise with a Medical Reserve Corps unit on the screening of large groups of individuals for possible contamination with radioactive material revealed that while exercise participants were generally attentive to the proper use of protective equipment and detectors, they tend...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.HP.0000324204.28443.ae
更新日期:2008-11-01 00:00:00
abstract::Software has been developed to aid in the management of a radiation safety quality control program in diagnostic radiology. The core of the system is a data base of radiation safety activities. Software design goals were the prioritization, scheduling, and reporting of these activities. Computerization has helped orga...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199201000-00015
更新日期:1992-01-01 00:00:00
abstract::This work describes the design, development, and characterization of an ionization chamber to detect and locate gamma ray sources with intensities down to 100 mu Gy h(-1). The results show that sources of x ray and gamma radiation in the energy range of 14 to 1,250 keV can be located. The directional sensitivity of th...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199604000-00007
更新日期:1996-04-01 00:00:00
abstract::During an invited visit to the University of Pittsburgh Medical Center (UPMC) gamma knife facility, officials from the Nuclear Regulatory Commission (NRC) observed what they considered as an apparent violation of the physical presence requirements specified in 10 CFR 35.615(f)(3). This event initiated an inspection an...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.HP.0000334061.89160.7f
更新日期:2009-02-01 00:00:00
abstract::An unventilated 70 m underground space, with 2.1 m high ceilings and an inner set of concrete walls to damp vibrations, was discovered to have relatively stable radon levels of ~1,080 Bq m over a 1-y period. The addition of radium sources was not required to achieve high and somewhat variable radon levels, as these ar...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0000000000001047
更新日期:2019-06-01 00:00:00
abstract::The calculation of radiation dose estimates to the fetus is often important in nuclear medicine. To obtain the best estimates of radiation dose to the fetus, the best biological and physical models should be employed. In this paper the most recent data available on the placental crossover of many radiopharmaceuticals ...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199711000-00002
更新日期:1997-11-01 00:00:00
abstract::A simultaneous detection of gross alpha and beta radioactivity was studied using gas proportional counting. This measurement is a part of a method mandated by US Environmental Protection Agency to screen for alpha and beta radioactivity in drinking water. Responses of a gas proportional detector to alpha and beta part...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-200111000-00011
更新日期:2001-11-01 00:00:00
abstract::The vertical distribution of weapons testing fallout 237Np has been determined in an undisturbed grassland soil (Alfisol). By using a compartmental model for multi-layered soils, the mean residence half-times of 237Np in each soil layer were calculated and compared with results on weapons fallout 239 + 240Pu, 241Am an...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199501000-00011
更新日期:1995-01-01 00:00:00
abstract::In recent years, regulatory emphasis on the prevention of loss, theft and intentional misuse of radioactive materials at academic institutions has forced radiation safety personnel to devote increasing amounts of time and effort to address security issues. NRC regulations require that radioactive materials used or sto...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-200311002-00009
更新日期:2003-11-01 00:00:00
abstract::More than 380 Chinese adults of both sexes were studied for their total body K and 40K using the National Tsing Hua University whole-body counter. The K values were found to have an average of 1.75 +/- 0.4 g K kg-1 body weight for males and 1.41 +/- 0.1 g K kg-1 body weight for females. The average K value for both se...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198911000-00006
更新日期:1989-11-01 00:00:00
abstract::Data were obtained from the literature for gonad and body weights and for the Pu or Ce content of the gonads and body at death for several laboratory animal species, five human Pu injection cases, and 731 human adults exposed environmentally to Pu in fallout. Data for Pu concentration in gonads, liver, and bone sample...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198907001-00012
更新日期:1989-01-01 00:00:00
abstract::More than 150 data sets giving time-dependent concentrations of 131I and 137Cs in feed and milk of cows after the Chernobyl accident are evaluated using a minimal compartmental modeling approach. Transfer of cesium via the grass-cow-milk pathway is adequately described by a three-compartmental model. No unique model r...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199406000-00005
更新日期:1994-06-01 00:00:00
abstract::Studies of laboratory animal retinal exposure to green monochromatic laser radiation show an increasing stability of tissue with increasing pulse duration up to 10(-1) s. This mechanism of biological response of the eye to light damage is fundamental to living systems. It does not manifest itself in animals under deep...
journal_title:Health physics
pub_type: 杂志文章,评审
doi:10.1097/00004032-198905000-00004
更新日期:1989-05-01 00:00:00
abstract::The (241)Am contents in the United States Transuranium and Uranium Registries' (USTUR) case 0102 leg phantom were previously estimated to be 1,243 ± 11 Bq. Recent analysis of the computed tomography images of the phantom revealed multiple bone structures missing from various regions of the phantom skeleton including: ...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/hp.0b013e318269bf81
更新日期:2013-01-01 00:00:00
abstract::Monte Carlo neutron transport calculations were performed to obtain the neutron response functions of a superheated drop detector (SDD-100) that is surrounded by polyethylene of various thicknesses. The calculational results suggest that a SDD-100 surrounded by 2.54 cm of polyethylene gives the best dose-equivalent re...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199203000-00001
更新日期:1992-03-01 00:00:00
abstract::An investigation of the performance of a diffusion barrier, charcoal-based 222Rn monitor under several artificial environmental conditions showed that both temperature and relative humidity levels affect 222Rn uptake. A physical model was developed adequately describing the temperature effects, while an empirical mode...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-199001000-00002
更新日期:1990-01-01 00:00:00
abstract::The Human Monitoring Laboratory has replaced its lung counting system with four large area (85 mm x 30 mm) HPGe detectors, electronics, and software. The system has been calibrated with the same lung set and phantom that was used to calibrate the Human Monitoring Laboratory's previous lung counting system and the Came...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/01.hp.0000167148.87179.b7
更新日期:2005-10-01 00:00:00
abstract::For much of the 20th century, U.S. radiation protection policies were similar to those elsewhere in the world, in large part because the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP) were closely aligned. In the 1970s, several U.S. r...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/HP.0000000000000236
更新日期:2015-02-01 00:00:00
abstract::Panasonic UD-801 thermoluminescent dosimeters ( TLDs ) containing two calcium sulfate phosphors were tested under Performance Specification 3.1 established by the American National Standard Institute ( ANSI75 ) and in the U.S. Nuclear Regulatory Commission's Regulatory Guide 4.13 ( NRC77 ). The specific qualifying tes...
journal_title:Health physics
pub_type: 杂志文章
doi:10.1097/00004032-198405000-00002
更新日期:1984-05-01 00:00:00