abstract：:Nuclear emulsions of the Ilford K series, exposed to X-rays from 15 to 150 kVp and systematically underdeveloped, exhibit supralinear blackness--exposure curves ranging from 1- to 4-hit in character, and whose shape is the same at all excitation voltages. Processing can be so adjusted that the curve shape is well repr...

journal_title：Physics in medicine and biology

authors： Katz R,Pennington EC

更新日期：1978-11-01 00:00:00

abstract：:The propagation of errors in quantitative biplane cineroentgenography was investigated to see which variables were the most critical. The analysis was carried out both for the propagation of root-mean-square errors and for errors as derived by a Taylor expansion of the reconstruction equations. The reconstruction is m...

journal_title：Physics in medicine and biology

authors： Smith WM,Starmer CF

更新日期：1978-07-01 00:00:00

abstract：:The feasibility of detecting gamma rays with energies below 1.5 MeV by means of a large-volume liquid-filled Cerenkov counter has been examined, together with the characteristics and limitations of an experimental counter. Various liquids (water, glycerol, sodium iodide solution; and glycerol plus a wavelength shifter...

journal_title：Physics in medicine and biology

authors： Hesp R

更新日期：1978-05-01 00:00:00

abstract：:New definitions of the absorbed dose conversion factors Clambda and CE are proposed. The absorbed dose in water is given by the product of absorbed dose conversion factor, exposure calibration factor, ionisation chamber reading, cap displacement correction factor and perturbation correction factor. At exposure calibra...

journal_title：Physics in medicine and biology

authors： Shiragai A

更新日期：1978-03-01 00:00:00

abstract：:An in vivo method for the determination of Cd levels in human kidney and liver has been developed. The method allows detection of absolute quantities of Cd in the left kidney and Cd concentration in the liver. The limit of detection of cadmium is 2.5 mg for the left kidney and 1.8 microgram/g (wet weight) for the live...

journal_title：Physics in medicine and biology

authors： Vartsky D,Ellis KJ,Chen NS,Cohn SH

更新日期：1977-11-01 00:00:00

abstract：:The possible use of fluorescence bronchoscopy for localization of bronchogenic tumours at the carcinoma in situ stage has been investigated. The target lesion is 80 micrometer thick with a mass of 250 microgram, containing 250 pg of haematoporphyrin derivative. The injected haematoporphyrin-derivative is preferentiall...

journal_title：Physics in medicine and biology

authors： Profio AE,Doiron DR

更新日期：1977-09-01 00:00:00

abstract：:Monte Carlo calculations of the energy response of LiF dosemeters have been carried out to help resolve the discrepancy between the measurements of Holt, Edelstein and Clark (1975) and those of Paliwal and Almond (1975) and others. It is concluded that the assumptions used by Holt et al. are largely responsible. They ...

journal_title：Physics in medicine and biology

authors： O'Brien K

更新日期：1977-09-01 00:00:00

abstract：:An X-ray technique has been developed to enable reproducible and quantitative data to be obtained from radiographs taken by a diagnostic X-ray machine. Careful attention has been paid to the alignment of the specimen and the diagnostic tube and to operating conditions. The choice of X-ray spectrum is described togethe...

journal_title：Physics in medicine and biology

authors： King SD

更新日期：1977-07-01 00:00:00

abstract：:An experimental investigation of the central axis depth-dose and stopping rate distribution of the SIN biomedical pion beam is reported. The pion stopping rate in a thin disc of tissue-equivalent plastic was determined using a counter telescope. The dose rate at the position of this dic 'target' was measured using a s...

journal_title：Physics in medicine and biology

authors： Nordell B,Baarli J,Sullivan AH,Zielczynski M

更新日期：1977-05-01 00:00:00

abstract：:A recently described, computer aided method of attenuation analysis has been applied to free-air chamber measurements of the attenuation by up to 30mm A1 of the exposure rate of a narrow beam of X-radiation excited at a thick W target in a Be window tube by constant potentials of 60, 80, 100, 120 and 140 kV. It has ...

journal_title：Physics in medicine and biology

authors： Soole BW

更新日期：1977-03-01 00:00:00

abstract：:The extent to which occupational radiation exposure contributes to cancer mortality is an influence on future world energy policy. It is also a factor in deciding the level of expenditure to reduce radiation levels experienced by workers. Here we discuss some of the difficulties in analysing the situation and presen...

journal_title：Physics in medicine and biology

authors： Reissland JA,Kay P,Dolphin GW

更新日期：1976-11-01 00:00:00

abstract：:A mathematical model has been constructed to simulate the response of cells in vitro to fractionated doses of radiation. The model is capable of describing most of the radiobiological functions that are commonly studied. Input data are measurable cell properties. The details of the model and methods of acquiring the i...

journal_title：Physics in medicine and biology

authors： Niederer J,Cunningham JR

更新日期：1976-09-01 00:00:00

abstract：:Detailed studies of the basic contrast mechanisms in computerized transverse axial tomography scanners have been carried out. Contrast is related to the effective atomic numbers and electron densities of materials and the resultant linear attenuation coefficients. We have therefore quantitatively evaluated various sam...

journal_title：Physics in medicine and biology

authors： Tsai CM,Cho ZH

更新日期：1976-07-01 00:00:00

abstract：:Calculations indicate that an assembly consisting of an antimony-beryllium source at the centre of a 4 cm radius water sphere surrounded by a 1 mm thick shell of boron-10 will emit neutrons with a broad spectrum at intermediate energies. A device based on this design was constructed using a water-filled, boron-carbide...

journal_title：Physics in medicine and biology

authors： Harvey JR,Bending RC

更新日期：1976-01-01 00:00:00

abstract：:The infrasonic part of the spectrum of the carotid artery wall vibration in the neck was obtained. Differences between the spectral content and vibrational amplitude in normal and occluded carotids were found. The application of this technique in clinical practice could be useful in the detection of the carotid insuff...

journal_title：Physics in medicine and biology

authors： Anastassiades AJ,Petounis AD

更新日期：1976-01-01 00:00:00

abstract：:We examined the reasons for the reduction in response of a multidetector radiation counting system when operated at high count-rates and established a convenient method of correction which is accurate to within +/- 1% up to 0-6 X 10(5) counts per second. In its application the method uses the observed count-rates from...

journal_title：Physics in medicine and biology

authors： Oxby CB,Oldroyd B,Appleby DB

更新日期：1976-01-01 00:00:00

abstract：:Average cross-sections for inactivation of dry ribonuclease by H, He and N projectiles with energies between 100 eV and 10 keV are presented. The trend of the damage cross-sections with particle energy is consistent with the trend of the molecular quasi-elastic scattering and ionization cross-sections. A tentative rad...

journal_title：Physics in medicine and biology

authors： Watt DE,Sutcliffe JF

更新日期：1975-11-01 00:00:00

abstract：:Many of the inadequacies of the system presently used for surveying environments containing penetrating radiation stem from the impossibility of defining a radiation parameter which is additive, measurable and closely related to peak dose equivalent in the body. Many of the present conceptual difficulties would be eli...

journal_title：Physics in medicine and biology

authors： Harvey JR

更新日期：1975-11-01 00:00:00

abstract：:The dearth of information on the physical processes involved in the propagation of ultrasound in tissue and the growing need for such information are discussed. The physical nature of the ultrasonic diagnostic process in considered in terms of a wave phenomenon and the limitations and advantages of frequency spectral ...

journal_title：Physics in medicine and biology

authors： Chivers RC,Hill CR

更新日期：1975-09-01 00:00:00

abstract：:A transformation method was investigated for applying the MIRD absorbed fraction to internal dose calculations for an individual. The transformation method consists of two parts, transformation of the target organ mass, and of the distance between source and target organs. The variation of the specific absorbed fracti...

journal_title：Physics in medicine and biology

authors： Yamaguchi H,Kato Y,Shiragai A

更新日期：1975-07-01 00:00:00

abstract：:The process of organ motion correction in scintigraphy is analysed in the frequency domain. The sequence of the chi- and gamma- coordinates registered during scintigraphic recording is converted to a frequency spectrum by a discrete Fourier transform. In the frequency domain motion correction is performed by linear fi...

journal_title：Physics in medicine and biology

authors： Schmidlin P

更新日期：1975-05-01 00:00:00

abstract：:Factors influencing the precision of measuring changes in the calcium content of sections of bone, including vertebrae, using reactor neutrons for partial body in vivo activation analysis have been examined and quantified. These factors include (a) the choice of incidient neutron spectrum, (b) the uniformity of activa...

journal_title：Physics in medicine and biology

authors： Boddy K,Glaros D,Robertson I

更新日期：1975-01-01 00:00:00