Increased knowledge transfer by using modern high-speed camera

A broad theoretical knowledge in Optics and Photonics is essential for media engineers. A combination of theory in the lectures augmented by practical work during the laboratory experiments forms the foundation of our gradual approach in communicating clearly and intensively all of the required topics. All laboratory experiments are guided but carried out by the students themselves and produced with a modern high-speed camera. This offers possibilities to analyze and iterate very fast phenomena. The slow motion footage makes it easily to analyze, to measure and to calculate certain sequences. This leads to a very intensive discussion regarding the provided topics and the used camera technology, resulting in a high standard knowledge transfer. Physics get now visible and more accessible for students. This paper presents how the students execute and analyze experiments using modern technology. The results are prepared as media-friendly computer animation and video recordings

Quality assurance of diatom counts in Europe: towards harmonized datasets

Investigations on organism ecology, biodiversity and biogeography often use large compiled datasets to extract information on species ecological preferences, which then can be used in environmental assessment. Freshwater benthic diatoms are commonly used in this context. However, it is important that the taxonomic information of the separate diatom datasets is compatible. At present, inconsistencies between diatom datasets, mainly due to differences and uncertainties in diatom identification, may misinform diatom taxon-specific ecological preferences, geographical distribution and water quality assessment. It is our opinion that these inconsistencies in diatom datasets can be reduced with quality assurance (QA), such as identification exercises. However, the results of these exercises must be well documented and well communicated; otherwise, gained knowledge may not spread inter-regionally or internationally. As a first step to reach greater consistency in QA/harmonization studies, this article (1) presents and compares information of existing diatom identification and counting QA from published and grey (non-peer reviewed) European literature to identify advantages and drawbacks of each approach; (2) summarizes taxa that can easily be misidentified according to European identification exercises; and (3) suggests a consistent design of identification exercises for diatom dataset QA

Phase quantification of ß-Si3N4/ß-SiC mixtures by X-ray powder diffraction analysis

X-ray powder diffraction methods of phase quantification were adapted and compared to mixtures of -Si3N4 and -SiC. Multiline mean-normalized-intensity methods and whole pattern analysis (Rietveld) both have advantages and disadvantages over each other. Satisfactory results (less than 3% absolute deviation) can be achieved in minimal time using intensity normalization methods. Phase quantification using the Rietveld method requires significantly longer measuring time, evaluation time and expertise to obtain the same results

Microcontrollers and optical sensors for education in optics and photonics

The digital revolution is going full steam ahead, with a constantly growing number of new devices providing a steady increase in complexity and power. Most of the success is based on one important invention: the microprocessor/microcontroller. In this paper the authors present how to integrate microcontrollers and optical sensors in the curricula of media engineering by combining subjects of media technology, optics, information technology and media design. Hereby the aim is not to teach these topics separate from each other, but to bring them together in interdisciplinary lectures, projects and applications. Microcontrollers can be applied in various ways to teach content from the fields of optics and photonics. They can be used to control LEDs, displays, light detectors and infrared sensors, which makes it possible to build measuring instruments like e.g. a lux meter, a light barrier or an optical distance meter. The learning goals are to stimulate the student’s interest in the multiplicity of subjects related to this course and to support a deeper understanding of the close connections between them. The teaching method that the authors describe in their paper turned out to be very successful, as the participants are motivated to bring in their own ideas for projects, they spend more time than requested and as many students return to the courses as tutors. It is an example for effectual knowledge transfer and exchange of ideas among students

Application of Statistical Methods for the Derivation of Usage Profiles of Mobile Excavators

Forderungen nach kürzeren Entwicklungszyklen bei gleichzeitig höherer Produktqualität führen in allen Bereichen der Nutzfahrzeugtechnik und insbesondere auch bei Baumaschinen zum verstärkten Einsatz von Simulationssoftware. Um in diesem Sinne Lebensdauerberechnungen durchführen zu können, sind jedoch genaue Kenntnisse über die im Kundeneinsatz auftretenden Betriebslasten und Beanspruchungen erforderlich. Für deren Ermittlung hat der Baumaschinenhersteller VOLVO Construction Equipment einen Mobilbagger umfassend mit Messtechnik ausgestattet, die neben den mechanischen Belastungen an der Arbeitsausrüstung auch wesentliche Kenndaten des Hydrauliksystems und des Fahrantriebs erfasst. Dieser Messbagger wurde bereits bei unterschiedlichen Kunden in Europa eingesetzt. Der Artikel beschreibt die methodische Vorgehensweise zur Verarbeitung der erfassten Daten und zur Generierung von repräsentativen Nutzungsprofilen am Beispiel der mechanischen Belastungen an der Arbeitseinrichtung, die im Wesentlichen vom Fraunhofer Institut für Techno- und Wirtschaftsmathematik (ITWM) erarbeitet wurde.The need for shorter development periods and yet improved product quality leads to an increasing use of numerical simulations in today’s commercial vehicle industry, in particular also in the construction machinery industry. For computer-based durability calculations, detailed knowledge regarding the service loads in customer usage is necessary as input data. To evaluate these loads, VOLVO Construction Equipment has extensively equipped a hydraulic mobile excavator with measurement devices. These measure the loads in the boom and arm and capture characteristic values of the hydraulic system and power train. This excavator has been used by various customers all over Europe. This article describes the systematic approach for the processing of the measured data and the generation of representative customer usage profiles, worked out mainly by Fraunhofer Institute for Industrial Mathematics (ITWM)

Application of Statistical Methods for the Derivation of Usage Profiles of Mobile Excavators

Forderungen nach kürzeren Entwicklungszyklen bei gleichzeitig höherer Produktqualität führen in allen Bereichen der Nutzfahrzeugtechnik und insbesondere auch bei Baumaschinen zum verstärkten Einsatz von Simulationssoftware. Um in diesem Sinne Lebensdauerberechnungen durchführen zu können, sind jedoch genaue Kenntnisse über die im Kundeneinsatz auftretenden Betriebslasten und Beanspruchungen erforderlich. Für deren Ermittlung hat der Baumaschinenhersteller VOLVO Construction Equipment einen Mobilbagger umfassend mit Messtechnik ausgestattet, die neben den mechanischen Belastungen an der Arbeitsausrüstung auch wesentliche Kenndaten des Hydrauliksystems und des Fahrantriebs erfasst. Dieser Messbagger wurde bereits bei unterschiedlichen Kunden in Europa eingesetzt. Der Artikel beschreibt die methodische Vorgehensweise zur Verarbeitung der erfassten Daten und zur Generierung von repräsentativen Nutzungsprofilen am Beispiel der mechanischen Belastungen an der Arbeitseinrichtung, die im Wesentlichen vom Fraunhofer Institut für Techno- und Wirtschaftsmathematik (ITWM) erarbeitet wurde.The need for shorter development periods and yet improved product quality leads to an increasing use of numerical simulations in today’s commercial vehicle industry, in particular also in the construction machinery industry. For computer-based durability calculations, detailed knowledge regarding the service loads in customer usage is necessary as input data. To evaluate these loads, VOLVO Construction Equipment has extensively equipped a hydraulic mobile excavator with measurement devices. These measure the loads in the boom and arm and capture characteristic values of the hydraulic system and power train. This excavator has been used by various customers all over Europe. This article describes the systematic approach for the processing of the measured data and the generation of representative customer usage profiles, worked out mainly by Fraunhofer Institute for Industrial Mathematics (ITWM)

Ein mathematisches Modell zur Schätzung der Dunkelziffer von SARS-CoV-2-Infektionen in der Frühphase der Pandemie am Beispiel Deutschland und Italien

Background!#!Especially in the early phase, it is difficult to obtain reliable figures on the spread of a pandemic. The effects of the COVID-19 pandemic and the associated comprehensive but incomplete data monitoring provide a strong reason to estimate the number of unreported cases.!##!Aim!#!The aim of this paper is to present a simple mathematical model that allows early estimation of the number of unregistered cases (underreporting).!##!Material and methods!#!Prevalences of reported infections in different age groups are combined with additional assumptions on relative contact rates. From this, a corrected prevalence is derived for each age group, which can then be used to estimate the number of unreported cases.!##!Results!#!Our model derives for Germany in mid-April 2020 about 2.8 times more total infections than registered cases. For Italy, the model results in a factor of 8.3. The case mortalities derived from this are 0.98% for Germany and 1.51% for Italy, which are much closer together than the case mortalities of 2.7% and 12.6% derived purely from the number of reports available at that time.!##!Conclusion!#!The number of unreported SARS-CoV-2-infected cases derived from the model can largely explain the difference in observations in case mortalities and of conditions in the early phase of the COVID-19 pandemic in Germany and Italy. The model is simple, fast, and robust to implement, and can respond well when the reporting numbers are not representative of the population in terms of age structure. We suggest considering this model for efficient and early estimations of unreported case numbers in future epidemics and pandemics

In-situ carbon content adjustment in polysilazane derived amorphous SiCN bulk ceramics

The paper is concerned with in-situ carbon content adjustment in amorphous bulk silicon carbonitride ceramic matrices prepared by thermal polymer to ceramic conversion of crosslinked and compacted poly(hydridomethyl)silazane powders (NCP200). Heat treatment under inert (Ar) or reactive (Ar/NH3, NH3) atmosphere was applied for carbon content adjustment. Isothermal annealing steps at various intermediate temperatures were included into the schedule. Optimal annealing temperatures were found to be in the range from 500 - 550°C. Results are presented. Different possible chemical reactions are considered