Microcontrolled pyro-electric instrument for measuring X-ray intensity in mammography

A novel instrument for measurement of X-ray intensity from mammography consists of a sensitive pyro-electric detector, a high-sensitivity, low-noise current-to-voltage converter, a microcontroller and a digital display. The heart of this device, and what makes it unique is the pyro-electric detector, which measures radiation by converting heat from absorbed incident X-rays into an electric current. This current is then converted to a voltage and digitised. The detector consists of a ferro-electric crystal; two types were tested; lithium tantalate and lithium niobate. X-ray measurement in mammography is challenging because of its relatively low photon energy range, from 11 keV to 15 keV equivalent mean energy, corresponding to a peak tube potential from 22 to 36 kV. Consequently, energy fluence rate or intensity is low compared with that of common diagnostic X-ray. The instrument is capable of measuring intensities as low as 0.25 mWm -2 with precision greater than 99%. Not only was the instrument capable of performing in the clinical environment, with high background electromagnetic interference and vibration, but its performance was not degraded after being subjected to 140 roentgen (3.6 × 10 -2 C kg -2 air) as measured by piezo-electric (d 33) or pyro-electric coefficients. © IFMBE 2005.

Towards an information society measurement instrument for Latin America and the Caribbean: getting started with census, household and business surveys

Includes bibliography

Flexibility and torsional resistance of three nickel-titanium retreatment instrument systems

Aim To assess the dimensional characteristics, flexibility and torsional behaviour of nickel-titanium retreatment instruments. Methodology Using image analysis software and high-resolution digital images, the instrument length, tip angle, diameter at 3mm from the tip and the distance between the blades (pitch length) of the following eight instruments were measured (n=12 for each measurement parameter): the ProTaper Universal retreatment (PTU-R) D1, D2 and D3 instruments; the R-Endo R1, R2 and R3 retreatment instruments; and the Mtwo retreatment (Mtwo-R) sizes 25 and 15 retreatment instruments. Maximum torque and the angular deflection at fracture as well as the bending moment at 45° were measured (n=12) according to the International Standards Organisation (ISO) specification number 3630-1. Data were analysed using the analysis of variance (α=0.05). Results The length of the active part of the instruments was found to vary according to the depth of the canal into which they were designed to reach. The pitch length also increased along the active length. The PTU-R D1 and the Mtwo-R instruments had active tips. Measurements of the bending moment at 45° revealed that the Mtwo-R 15 instrument was the most flexible, whereas the PTU-R D1 was the least flexible. The maximum torque tended to increase as the instrument diameter at 3mm from the tip increased, whereas the angular deflection at fracture varied in the opposite direction. Conclusions The geometrical characteristics of the retreatment instruments and their flexibility and torsion behaviour were consistent with their intended clinical application. © 2011 International Endodontic Journal.

The evaluation of an instrument for pediatric oncology patient classification

The objectives of this study were to assess the interrater reproducibility of the instrument to classify pediatric patients with cancer; verify the adequacy of the patient classification instrument for pediatric patients with cancer; and make a proposal for changing the instrument, thus allowing for the necessary adjustments for pediatric oncology patients. A total of 34 pediatric inpatients of a Cancer Hospital were evaluated by the teams of physicians, nurses and nursing technicians. The Kappa coefficient was used to rate the agreement between the scores, which revealed a moderate to high value in the objective classifications, and a low value in the subjective. In conclusion, the instrument is reliable and reproducible, however, it is suggested that to classify pediatric oncology patients, some items should be complemented in order to reach an outcome that is more compatible with the reality of this specific population.

Expert opinion as an instrument for assessing investment in primary education

Includes bibliography

A tax on currency transactions as an instrument in the war against poverty

Includes bibliography

The public corporation: an adequate instrument for the supply of electric power

Includes bibliography

Informe del Seminario sobre las Evaluaciones del Impacto Ambiental como Instrumento de Gestión del Medio Ambiente: Situación y Perspectivas en América Latina y el Caribe = Report of the Seminar on Environmental Impact Assessments as an Instrument of Environmental Management: Situation and Prospects in Latin America and the Caribbean

Contiene asistencia, organización de los trabajos y resumen de los debates de la reunión que tuvo como principal objetivo analizar aspectos de la cooperación internacional en materia de evaluaciones del impacto ambiental.

Poverty measurement as an instrument to design, monitor and evaluate health policy in Chile

Includes bibliography

Instrument for the sensitisation of policy makers about the value of science and technology

Pretende crear conciencia en los encargados de la toma de decisiones de la importancia de integrar los programas de ciencia y tecnologia en los planes nacionales de desarrollo.

Strengthening value chains as an industrial policy instrument. Methodology and experience of ECLAC in Central America

Foreword by Alicia Bárcena.

Roundtable discussion on the nature of the regional instrument: Summary of the answers and the comments from experts in public environmental international law

This document summarizes the development and conclusions of the sixth meeting of the working group on access rights and the regional instrument held virtually on August 1st, 2014. The meeting, which was for information purposes only, had the aim of advancing in the discussions on the nature of the regional instrument by holding a round table discussion with the renowned experts in Public International Law.