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Dive into the research topics where Brian Pullan is active.

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Featured researches published by Brian Pullan.


Nuclear Instruments and Methods | 1975

Spiral cathode spark chambers for radiochromatography

Brian Pullan; João José Pedroso de Lima

Abstract This paper describes and discusses the performance of spark chambers which are designed to visualise the distribution of β-emitting radioactivity on chromatograms. The chambers comprise an assembly of individual detectors with spiral wire cathodes and concentric wire anodes. This design leads to ease of construction with good uniformity of sensitivity and stability of operation; sufficient for routine use in radiochromatography.


Nuclear Instruments and Methods | 1975

Spurious events in spiral cathode spark chambers

João José Pedroso de Lima; Brian Pullan

Abstract The main difficulty in using spark chambers in routine laboratory applications such as autoradiography is the appearance of spurious sparks which are not associated with the passage of ionisation radiation through the gas of the detectors. This paper describes an investigation of the production of initiatory electrons from the cathode surfaces of detectors by field emission effects. Electron emission rates from cathode surfaces have been measured as a function of applied electric field, cathode material and spark frequency. The results show that emission rates are high enough to account for a significant proportion of spurious sparks. Other effects leading to ionisation in the gas will also contribute to the spurious sparking rate. Conclusions are drawn as to suitable materials for spark counter cathodes.


Nuclear Instruments and Methods | 1971

A position sensitive Geiger counter

J.J.P. de Lima; Brian Pullan

Abstract The position of a detected ionising particle in a Geiger counter is determined by measuring the arrival times of an avalanche at the two ends of the counter. The design of a Geiger counter and associated electronics is described. The system is capable of a position resolution of 0.4 cm and a stability of 1% in position measurement provided the voltage on the counter, the pressure and temperature are stabilised.


Physics in Medicine and Biology | 1972

A computer simulation of the performance of a spark chamber gamma camera.

J J P de Lima; Brian Pullan

The response of a spark chamber gamma camera to three-dimensional test objects has been simulated in a computer. The simulation was based on efficiency and point response function measurements for single parallel hole collimators using a Geiger counter as the detector. Measurements and simulations were also done using a NaI scintillation detector. A comparison of the two simulations shows that the product of activity in test objects and exposure time for the spark chamber system is of the order of 1000 times that for a NaI scintillation detector for the same visualization statistics. This results from the spark chambers low detection efficiency and a loss of contrast caused by an inability to discriminate against scattered radiation.


Continuity and Change | 1988

Support and redeem: charity and poor relief in Italian cities from the fourteenth to the seventeenth century

Brian Pullan


The Historical Journal | 1977

‘A Ship with Two Rudders’: ‘Righetto Marrano’ and the Inquisition in Venice

Brian Pullan


Journal of Early Modern History | 2000

Religion and the Rise of Poor Relief

Brian Pullan


The American Historical Review | 2011

James William Brodman . Charity and Religion in Medieval Europe . Washington, D.C. : Catholic University of America Press . 2009 . Pp. xi, 318.

Brian Pullan


The American Historical Review | 2009

59.95.

Brian Pullan


The American Historical Review | 2007

DANA E. KATZ. The Jew in the Art of the Italian Renaissance. (Jewish Culture and Contexts.) Philadelphia: University of Pennsylvania Press. 2008. Pp. xi, 228.

Brian Pullan

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J.J.P. de Lima

University of Manchester

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