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Foto des neuartigen 300 GHz-Detektors

Until now, it has not been possible to measure the radiated power of millimeter waves in the terahertz spectral range in the so-called H-band with frequencies from 220 GHz to 330 GHz traceable to the International System of Units. The solution to this problem is a new type of terahertz detector, which was developed as part of a Franco-German cooperation project.

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A working group of the Consultative Committee for Time and Frequency (CCTF), with the participation of PTB, has drawn up a plan for a future redefinition of the second based on the progress made with optical atomic clocks. The progress achieved and the improvements still required are being discussed in order to secure in the long term and to improve the quality of frequency measurements and time...

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PTB and NIST performed a comparison for high accuracy continuous wave optical power measurements in the kilowatt regime. The NIST carried out measurements with a power meter relying on photon momentum, while PTB performed the measurements with a modified off-the-shelf thermal power meter. The non-absorbing photon momentum measurement approach permits the two power meters to measure the same laser...

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a)Aufsicht auf einen graphenbasierten Quanten-Hall-Widerstand mit aufgebrachter Epoxid-Diffusionsbarriere b) Schaltung im Probenhalter mit zusätzlich aufgesetzter Steckplatine oberhalb der Schaltung

Ein neuer Ansatz zur Entwicklung stabiler graphenbasierter Quantenwiderstandsnormale verfolgt die Anwendung eines Flip-Chip-Verfahrens zur Probenkontaktierung, welches ohne Bonddrähte auskommt. Erwartete Vorteile gegenüber der herkömmlichen Drahtkontaktierung umfassen neben erhöhter Kompaktheit und Kontaktierungsgenauigkeit auch Möglichkeiten zur elektrischen Abschirmung der Proben sowie deren...

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Darstellung eines bidirektionalen Ladevorgangs (oben) und eines dynamischen induktiven Ladevorgangs (unten)

Werden Messwerte bei der Lieferung von elektrischer Energie als Grundlage für die Abrechnung und damit für den geschäftlichen Verkehr herangezogen, sind die Messwerte vom Eichrecht geschützt und müssen daher eichrechtskonform erfasst werden. Die PTB arbeitet in drei neuen, durch das Bundesministerium für Wirtschaft und Klimaschutz geförderten Forschungsprojekten mit, um den Verbraucherschutz bei...

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The characterization of dispersions, suspensions, and emulsions is important in a wide range of scientific and industrial applications. Samples may consist of different materials with a wide range of particle sizes and concentrations. In a technology transfer project with LUM GmbH, a single particle sizing and counting instrument with a dynamic detection range of ≥6 decades has been developed to...

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The sound power level characterises the total amount of sound emitted by a source. Due to this basic importance it is used in many legal and other regulations in occupational health, environmental control and consumer protection. The sound power level is measured in accordance with about 10 different internationally harmonised basic standards. Here, quantities directly measured are either the...

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The separate imaging of fat and water rich tissue is a frequent objective in magnetic resonance imaging (MRI). An efficient solution is provided by the Dixon technique where both compartments are excited simultaneously and the signals are later separated based on their different temporal evolution. At the 'ultrahigh' MRI field strength of 7T, the frequency shift between fat and water protons is...

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Abbildung: Graphische Darstellung des Signal-Interpretieren Petri-Netzen (SPIN) der Energiezustände

Research work at PTB is concerned with the analysis, modelling and performance optimisation of energy states in mobile embedded systems. The approach is also transferable to other IT systems, such as data centres.

Mobile devices have become an integral part of communication, business and social interactions. The energy consumption of such systems is constantly increasing due to the ever-expanding...

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WELMEC Legal Metrology Banner

The WELMEC Working Group 7 "Software" [1] of the European Cooperation in Legal Metrology (WELMEC) [2] met online for its 29th meeting on 28 February 2024. The working group is chaired by PTB's Division 8.5 "Metrological IT".

WELMEC Working Group 7 "Software" develops technical interpretations of the essential requirements of the European Measuring Instruments Directive (MID) and incorporates...

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Last fall, the research paper "Wirelessly interfacing sensor-equipped implants and MR scanners for improved safety and imaging" by Berk Silemek, Lukas Winter, and colleagues was published in Magnetic Resonance in Medicine (MRM). This article was now chosen as an MRM Highlights Pick "… because they openly shared design files and software for the MRI implant sensor they developed" (see gitlab1.ptb...

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Single photon emitters in hexagonal boron nitride have gathered a lot of attention due
to their favourable emission properties and the manifold of possible applications. Despite
extensive scientic effort, the exact atomic origin of these emitters has remained unkown
thus far. Recently, several studies have tied the emission in the yellow spectral region
to carbon-related defects, but the exact atomic...

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The optical constants fully describe how a material transmits, reflects, absorbs, refracts or scatters light. Their precise knowledge is therefore of central importance for optical technology. As part of the European joint projects "Advanced Traceable Metrology for Optical Constants" (ATMOC) and "14 Angstrom CMOS IC technology" (14ACMOS), PTB has started to build up a database of optical constants...

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In a cooperation project between the PTB departments “Detector Radiometry and Radiation Thermometry” and “International Cooperation”, the Federal Association for Wholesale, Foreign Trade and Services (BGA) and the Business Scout for Development programme of the Federal Ministry for Economic Cooperation and Development (BMZ), a simple but effective cooling effect was demonstrated on buildings in...

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Die PTB-Bibliothek setzt ihre Unterstützung der Open-Access-Transformation durch den erneuten Abschluss der DEAL-Verträge mit den Verlagen Springer Nature und Wiley fort.

Die vom DEAL-Konsortium ausgehandelten Vertragskonditionen beinhalten sowohl den lesenden Zugriff auf das Zeitschriftenportfolio der beiden Verlage als auch die zentrale Abrechnung der Publikationskosten.

Bei diesen zweiten...

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Mithilfe von kurzwelliger und energiereicher UVC-Strahlung werden schon seit Jahrzehnten Oberflächen, Trinkwasser oder Raumluft desinfiziert. Dabei nutzt man aus, dass diese Strahlung Zellen schädigen kann – insbesondere diejenigen von Viren, Bakterien oder anderen Mikroorganismen. Allerdings kann sie auch Zellen in menschlichen Organen wie Haut und Auge schädigen. Die radiometrische Kalibrierung...

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An independent international group of researchers from academics and national agencies formed a dedicated task group within the American Association of Physicists in Medicine to identify key image quality characteristics and objective test methods for macroscopic fluorescence-guided surgery (FGS). The minimum set of measurements considered important for basic device performance are image sharpness,...

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PhD completed

Sebastian Dietrich-Conzelmann successfully defended his PhD thesis "Quantitative MRI for assessment of myocardial fat infiltration at ultra-high field strength" at the Faculty V – Mechanical Engineering and Transport Systems, Chair of Medical Engineering, of the Technical University Berlin. His work at PTB was supervised by Sebastian Schmitter, Head of PTB's Ultrahigh Field MRI Group 8.14....

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