Der graue Star (Katarakt) zählt zu den häufigsten Erkrankungen im Alter und ist durch eine Trübung der Augenlinse gekennzeichnet. Im Fall einer deutlichen Absenkung der Sehschärfe wird die getrübte Augenlinse mittels Ultraschall entfernt (Phakoemulsifikation) und durch eine Kunststofflinse ersetzt. Als Komplikationen während der Operation können hierbei thermische Schäden auftreten. An der PTB...

The reference hearing thresholds for a commercially available otoacoustic emission probe were determined. This will enable the application of this probe also in subjective hearing tests.

Sophisticated radiochemical investigations have allowed Ca-41 to be extracted from nuclear material. The number of Ca-41 atomic nuclei contained in the material obtained was determined by means of thermal ionization mass spectrometry (TIMS). At PTB, the activity of the radionuclide was measured for the first time using the TDCR method. The half-life of the long-lived isotope Ca-41 was determined...

At PTB, imaging with magnetic resonance could for the first time be carried out at frequencies below 1 kHz. This procedure could open up new possibilities for neurosciences.

In enger Zusammenarbeit mit der Charité und der Freien Universität wurde ein neuartiges Konzept für das Gebiet der zellulären und molekularen Metrologie entwickelt und untersucht, das eventuell die Verwendung komplexer Sonden ersetzen kann. Das dabei verwendete System ist in der Lage die Fluoreszenzemission des endogenen Fluorophors Protoporphyrin ...

Effect of different protection mechanisms for the pressure transducer diaphragms of piezoelectric sensors on the point pressure during the gas pressure measurement on ammunition for short firearms.

It could be shown by a comprehensive measurement program and additional computer simulations that the installation noise levels according to the new standard DIN EN ISO 10052 are larger by 2 dB than the levels determined in accordance with the old standard DIN 52219.

Forty-eight participants from Germany, Austria, France and Switzerland gathered at the 7th LSC user meeting to obtain information and exchange their experiences on the latest developments in the field of liquid scintillation counting for activity measurements.

PTB has been characterizing optical components and detectors in the VUV and EUV spectral ranges by means of synchrotron radiation for a long time. To date, there had been, however, no possibility of performing measurements in the wavelength range from 30 nm to 40 nm. This spectral range is important, for example, to study in space the physical properties of the sun. One of the objectives with the...

To guarantee the worldwide uniformity of dosimetry and the international recognition of PTB calibrations, PTB participated in the key BIPM-organized comparison BIPM.RI(I)-K6, in which the primary standards of PTB and of the BIPM for the realization of the unit "absorbed dose to water" were compared in high-energy photon fields on accelerators. The measurements for this comparison - for which the...

High-intensity therapeutic ultrasound (HITU) is a non-invasive and non-ionizing therapy method in which locally very high ultrasonic intensities (> 10 kW/cm²) can be produced in the body by focusing an ultrasonic field. These high intensities then induce, for example, necrotization and thus the destruction of tumor tissue. Although the number of applications is constantly increasing, there are...

For PTB's reference facility for vehicle speeds, which is based on piezoelectric pressure sensors, the measurement uncertainty budget was verified by comparisons with a high-quality GPS inertial system.

The numerical simulation of a non-linear parabolic equation (the KZK equation) can be favorably applied to the determination of extremely high pressure amplitudes of modern therapeutic ultrasound devices and complement the experimental hydrophone measurement technique.

The national metrology institutes prepare intensively for the redefinition of the base units which is scheduled - from 2015 on – to be traced back to fundamental constants. For that purpose, recommendations for implementation - so called Mises en Pratiques - are elaborated and published. According to the planned redefinition of the Kelvin - the base unit for the temperature - temperature...

The FATAL (A modelling framework for Fault-Tolerant Asynchronous Logic) project is aimed at developing a simulation model for asynchronous logic which takes the impacts of radiation effects on the circuit into account. On the basis of this model, it shall in future be possible to develop asynchronous logic which is resistant to radiation effects.

The 'Innovation Award on Synchrotron Radiation 2011' was given to U. Kroth, M. Richter (PTB Berlin), K.Tiedtke, U. Jastrow, A. A. Sorokin (DESY Hamburg) and S.V. Bobashev (Joffe Physico-Technical Institute, St Petersburg). On 1 December 2011, they received the Innovation Award in Berlin for their contributions to the development and implementation of gas monitor detectors (GMDs) for free-electron...

In the past three years, the European iMERA-Plus research project "Candela: Towards quantum-based photon standards" (http://www.quantumcandela.org) has been focused on the further development of both, the classical radiometry and the radiometry of a few photons and the linkage of both. For this purpose, a calculable, high-efficiency radiation detector was developed on the basis of special silicon...

Mit großem Interesse sind die im November 2010 und November 2011 von der PTB durchgeführten sowie vom Helmholtz-Fond und WELMEC geförderten Workshops zu je einem informationstechnischen Schwerpunktthema des gesetzlichen Messwesens aufgenommen worden. Während ...

Der Fachbereich „Mathematische Modellierung und Datenanalyse“ hat zur für diesen Bereich wesentlichen Konferenz „Advanced Mathematical and Computational Tools for Metrology“ (AMCTM 2011) einen dominanten Beitrag (mehr als 10 Vorträge, 4 von 12 ausgewählten Plenarvorträgen) geleistet. Er prägt zudem ...

Die Bestimmung der Masse in großen Lagertanks erfolgt durch zwei unabhängige Messungen zu Volumen und Temperatur. Durch Verringerung der Messunsicherheit bei der Ermittlung der mittleren Tanktemperatur ...