A5049213862- Advanced Thermoelectric Materials and Devices
- Surface and Thin Film Phenomena
- Semiconductor Lasers and Optical Devices
- Advanced Machining and Optimization Techniques
- Photonic and Optical Devices
- Advanced machining processes and optimization
- Advanced Sensor Technologies Research
- Advanced Surface Polishing Techniques
- Semiconductor materials and interfaces
- Calibration and Measurement Techniques
- Thermodynamic and Structural Properties of Metals and Alloys
- Semiconductor Quantum Structures and Devices
- Molecular Junctions and Nanostructures
- Crystallography and molecular interactions
- Crystallization and Solubility Studies
- Thermal properties of materials
- Thermography and Photoacoustic Techniques
- X-ray Diffraction in Crystallography
- Radioactive element chemistry and processing
- Physics and Engineering Research Articles
- Technology Assessment and Management
- Surface Roughness and Optical Measurements
- Analytical chemistry methods development
- Spaceflight effects on biology
- Marketing and Advertising Strategies
Physikalisch-Technische Bundesanstalt
2012-2022
Leipzig University
2014
OSRAM (Germany)
2011
University of Duisburg-Essen
2011
Karlsruhe Institute of Technology
2006-2009
Abstract The paper describes a measuring system and method to measure the Seebeck coefficient electrical conductivity of different bulk materials. Some improvements original setup allow reduction achievable relative measurement uncertainty regarding few percent. This is demonstrated by results measurements metallic semiconducting samples (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In this paper, we describe a measuring system based on the Van der Pauw principle with four calibrated type S thermocouples. By means of system, conducted traceable measurements absolute Seebeck coefficients and electrical conductivity thermoelectric bulk materials to establish precise determination power factor. The results comparative investigation metallic (ISOTAN® Nickel) semiconducting (SiGe) in temperature range 300 K-1100 K are presented. good agreement conductivities measured using...
Due to the ongoing miniaturisation in industrial sectors like automotive, electronics or medical, development of new manufacturing processes which are suitable for micro system technologies gains more and importance. The components leads challenges parts. One application area is moulds powder injection moulding (μPIM) process. This process requires good surface qualities a sufficient demoulding behaviour moulds. Micro milling, electrical discharge machining (μEDM) laser beam (μLBM)...
Thermocouples are often exposed to harsh conditions when used for high-temperature measurements in industry. They suffer commonly from unavoidable drift effects which influence the required process efficiency and control. A self-validation concept thermocouples monitor their performance temperature range between 1000 C about 1800 oxidizing atmospheres by using integrated miniature fixed-point units of different designs was tested. Two models crucibles filled with high purity palladium...
Laser projectors integrated in portable devices offer a new platform for media display but put strong demands on the laser sources terms of efficiency, modulation band width, operating temperature range and device cost. Osram Opto Semiconductors has developed produces synthetic green lasers projection applications which latest results are reported. Based vertical external cavity surface emitting (VECSEL) technology second harmonic generation an output power >75mW been achieved. The maximum...
Using laser beam machining with ultrashort pulses, microstructures in the micrometer region can be manufactured virtually all materials, regardless of their mechanical properties. However, times are slow if good surface qualities required. Micro electrical discharge (EDM) is also capable removing material nearly without process forces, but a higher processing speed structure sizes exceed certain value. With combination both processes, specific advantages realized while disadvantages...
In this paper, we measure and analyze the pump power wavelength dependent gain of an optically pumped infrared 1050-nm vertical external-cavity surface-emitting laser (VECSEL) developed for application as a frequency doubled green in mobile projectors. Increasing reflectivity chip coating from 3% to 20% is found result maximal 7.9%, more than twice high that coating, spectral narrowing wavelength-dependent consequence enhanced coupling between optical field quantum well medium. From our...
We have developed an optically pumped infrared 1060-nm vertical-external-cavity surface-emitting laser for application as a frequency doubled green in mobile projectors. The efficiency has been investigated function of pump wavelength and differential η <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">diff</sub> 50% demonstrated using 808-nm source. usage longer decreases the quantum defect increases to over 52%. light absorption chip is absorber...
We investigate cross-correlations in the tunneling currents through two parallel quantum dots coupled to independent electrodes and gates interacting via an inter-dot Coulomb interaction. The correlations reveal additional information, beyond what can be learned from current or conductance, about dynamics of transport processes system. find qualitatively different scenarios for dependence on gate voltages. Reducing temperature below interaction, regions a given sign change spherical shapes...
Zusammenfassung Der Zweifel am Klimawandel reicht bis in hohe politische Ämter, wie die Beispiele USA und Brasilien zeigen. Doch auch Deutschland versuchen Organisationen, Publizisten Interessenvertreter, Öffentlichkeit davon zu überzeugen, dass Klimaforschung irrt. Wie erfolgreich sind sie damit? Ein Vergleich zwischen den Klimaskeptikern bzw. Klima(wandel)leugnern zeigt erhebliche Unterschiede auf – etwa im Hinblick Finanzen, Organisationsgrad mediale Reichweite. Andererseits bestehen...
By laser ablation with ultra short pulses smallest microstructures sizes in the micrometer region can be manufactured hardened steel. However, machining times are slow if good surface qualities required. Micro-EDM (electric discharge machining) is also capable of removing material without any process forces but a higher processing speed structure exceed certain value. quality worse than ablation. With combination both processes specific advantages utilized while disadvantages partially...
Zusammenfassung In diesem Beitrag werden der konstruktive Aufbau graphitbasierter Thermoelemente, die Ergebnisse von Messungen absoluter Seebeck-Koeffizienten zum Bau Thermoelemente verwendeten Graphitmaterialien bis ca. 550 ○ C und metrologischer Untersuchungen graphitbasierten Thermoelementen bezüglich ihrer thermoelektrischen Stabilität 1950 beschrieben.
Technical systems designed with the ability to be adaptable changes could longer valuable for stakeholders and thus remain competitive in market. The system properties that provide value if modified future (Key Parameters) are ones should adaptably. In order identify KPs of technical systems, a methodology was developed. This paper presents workshop carried out cooperation industry apply real obtain its KPs. results presented, analyzed discussed.
The paper at hand builds up on the fundamentals developed within field of Real Options Analysis (ROA) and presents monetary assessment two Architectures a Carbon Fibre Placement System with different degrees Adaptability. analysis is based decisive Key Parameters (KPs), that capture physical, functional, other performance aspects are subjective value to one or several stakeholders. It pays tribute crucial influence uncertainty both from technological as well market point view by use...