The Effect of Pressure on Ion Track Formation in Minerals

In many dielectrics, energetic heavy ions produce thin cylindrical damage zones along their trajectories. Massive physical and chemical changes can occur in these ion tracks with diameters of several nm. In nature, such trails are generated by spontaneous fission of 238U-nuclei. So far, irradiation experiments with heavy ions were always performed under vacuum conditions. Studies of ion-track formation in pressurized solids are expected to contribute to an improved understanding of the creation conditions for fission tracks in the Earth�s crust. Such experiments will be important for dating of geological samples using the fission-track technique. In addition, it is a question of great interest whether the energy deposition of swift heavy ions in a solid, being exposed to extreme pressure, can induce specific phase transitions. This work describes the first experiments on ion track formation under high pressures up to 140 kbar which were performed at GSI by injecting relativistic heavy ions, accelerated with the SIS-heavy-ion synchrotron, through the diamond anvils of a high-pressure cell. It turned out that high pressures can significantly affect the interaction between heavy ions and solids. The effects observed include the suppression of track formation, the complete recrystallization, and the nucleation of new phases

Bitter taste receptors of the zebra finch (Taeniopygia guttata)

Despite the important role of bitter taste for the rejection of potentially harmful food sources, birds have long been suspected to exhibit inferior bitter tasting abilities. Although more recent reports on the bitter recognition spectra of several bird species have cast doubt about the validity of this assumption, the bitter taste of avian species is still an understudied field. Previously, we reported the bitter activation profiles of three zebra finch receptors Tas2r5, -r6, and –r7, which represent orthologs of a single chicken bitter taste receptor, Tas2r1. In order to get a better understanding of the bitter tasting capabilities of zebra finches, we selected another Tas2r gene of this species that is similar to another chicken Tas2r. Using functional calcium mobilization experiments, we screened zebra finch Tas2r1 with 72 bitter compounds and observed responses for 7 substances. Interestingly, all but one of the newly identified bitter agonists were different from those previously identified for Tas2r5, -r6, and –r7 suggesting that the newly investigated receptor fills important gaps in the zebra finch bitter recognition profile. The most potent bitter agonist found in our study is cucurbitacin I, a highly toxic natural bitter substance. We conclude that zebra finch exhibits an exquisitely developed bitter taste with pronounced cucurbitacin I sensitivity suggesting a prominent ecological role of this compound for zebra finch

In situ defect annealing of swift heavy ion irradiated CeO2 and ThO2 using synchrotron X‐ray diffraction and a hydrothermal diamond anvil cell

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111991/1/S160057671500477X.pd

Influences of Extraction Techniques on the Quality of Measured Quantities of Pedestrian Characteristics

For the proper understanding and modelling of pedestrian dynamics, reliable empirical data are necessary. Trajectories of every person with a high temporal and spatial resolution allow a detailed analysis of movement as well as the calibration and verification of microscopic models in space and time.To extract individual trajectories on a microscopic level different techniques have been developed de- pending on miscellaneous requirements. In this paper we analyse how the quality of quantities like velocity or density depend on the technique chosen to track pedestrians. For this purpose, errors due to perspective distortion, use of markers, type of markers, and other conditions will be scrutinized.It turns out that the usage of imaging systems like cameras give currently the best results and that marker particularly structured marker for detecting a person in a crowd obtain the most accurate trajectory especially if the height of the person is coded by the marker or the distance to the camera is measured otherwise. To minimize the errors resulting from the perspective view a small angle of view and thus high mounted cameras should be used for capturing the whole area of interest. The small angle of view also decreases the risk of occlusion and lens systems for large focal lengths usually have a smaller optical distortion error

What influences the decision to drop out? Longitudinal analyses of the interplay between study satisfaction, content knowledge and dropout intention in chemistry, engineering and social sciences

Die Untersuchung der Gründe für den Studienabbruch von Studierenden in MINT-Fächern ist wegen des akuten Fachkräftemangels von großer Bedeutung. Dabei ist bisher wenig über Unterschiede zwischen MINT-Studiengängen, aber auch im Vergleich zu anderen Studiengängen, hinsichtlich der Abbruchgründe bekannt. Die längsschnittlich angelegte Studie untersucht daher individuelle Einflussfaktoren auf den Studienerfolg und Studienabbruch in zwei typischen MINT-Studiengängen (Chemie und Maschinenbau) und kontrastierend dazu in Studiengängen aus dem sozialwissenschaftlichen Bereich (Politikwissenschaft, Soziologie, Soziale Arbeit). Während in bisherigen Studien (z.B. Heublein et al., 2017) fachübergreifende Prädiktoren für den Studienabbruch identifiziert werden konnten, wurde in den Analysen dieser Studie festgestellt, dass sich diese zwischen den Fächern und auch zwischen unterschiedlichen Hochschultypen sehr unterschiedlich auswirken. Vor allem die Sozialwissenschaften zeigen im Vergleich zu den MINT-Fächern einen deutlich geringeren Einfluss des Fachwissens auf den Studienabbruch. (DIPF/Orig.)In view of the current shortage of qualified personnel in STEM subjects, the investigation of the reasons for dropping out of university studies is of great importance. Little is known about the differences between STEM study programmes and other study programmes with regard to the reasons for dropping out. The longitudinal study of this project therefore examines the factors influencing the success and termination of studies in two typical STEM programmes (chemistry and mechanical engineering) and, in contrast, in programmes of the social sciences (political science, sociology, social work). Based on Heublein et al. (2017), data were collected to identify subject-specific factors influencing the dropout of students. The results of path analyses indicate that dropout by students of social sciences is less influenced by content knowledge compared to STEM study programmes. (DIPF/Orig.

Agroforestry : an appropriate and sustainable response to a changing climate in Southern Africa?

CITATION: Sheppard, Jonathan P. et al. 2020. Agroforestry : an appropriate and sustainable response to a changing climate in Southern Africa? Sustainability 12(17):6796, doi:10.3390/su12176796.The original publication is available at: https://www.mdpi.comENGLISH ABSTRACT: Agroforestry is often discussed as a strategy that can be used both for the adaptation to and the mitigation of climate change e ects. The climate of southern Africa is predicted to be severely a ected by such changes. With agriculture noted as the continent’s largest economic sector, issues such as food security and land degradation are in the forefront. In the light of such concerns we review the current literature to investigate if agroforestry systems (AFS) are a suitable response to the challenges besetting traditional agricultural caused by a changing climate. The benefits bestowed by AFS are multiple, o ering ecosystem services, influence over crop production and positive impacts on rural livelihoods through provisioning and income generation. Nevertheless, knowledge gaps remain. We identify outstanding questions requiring further investigation such as the interplay between trees and crops and their combination, with a discussion of potential benefits. Furthermore, we identify deficiencies in the institutional and policy frameworks that underlie the adoption and stimulus of AFS in the southern African region. We uphold the concept that AFS remains an appropriate and sustainable response for an increased resilience against a changing climate in southern Africa for the benefit of livelihoods and multiple environmental values.Publisher's versio

„Projektierung und Implementierung einer bildverarbeitungsbasierten Systemkomponente als Element des Strahlenschutzes“

Das Ziel der Arbeit ist die Verbesserung des Sicherstandards eines Röntgenlabors. Mit diesem System soll das Labor auf sich darin befindliche Personen überprüft werden. Somit kann sichergestellt werden, dass sich während des Betriebs der im Labor befindlichen Röntgenanlage keine Person im Labor aufhält. Es wird so ausgeschlossen, dass Personen Röntgendosisleistungen ausgesetzt werden, die schädigende Wirkungen auf den menschlichen Organismus haben. Die Erkennung von Personen soll durch die Installation einer bildverarbeitungsbasierten Systemkomponente bestehend aus PC, Kamera und Bildverarbeitungssoftware im Labor realisiert werden. Zur Festlegung der in Anwendung kommenden Komponenten sollten mehrere alternative Lösungskonzepte aufgezeigt und mittels einer Bewertungsmatrix verglichen werden, um das für diese Anwendung zweckdienlichste System zu ermitteln. Die zu erstellende Systemkomponente soll über ein Relais, als Schnittstelle zum vorhandenen Sicherheitskreis, in das bestehende Personensicherheitssystem eingefügt werden, um den Betrieb der Röntgenanlage an die zu erstellenden Systemkomponente zu koppeln. Mit einer in der Bildverarbeitungssoftware zu erstellenden Applikation, die über eine Datenerfassung das Relais steuert, soll bei Erkennung von Personen im Labor der Betrieb der Röntgenanlage unterbrochen werden oder gar nicht erst ermöglicht werden

Packaging-Strategien für robuste Netze: Das "Internet der Dinge" treibt die Vernetzung in Wirtschaft und Gesellschaft voran

Ob Smart Home, Smart Grid, Smart City oder Industrie 4.0, immer wenn Szenarien der Zukunft gemalt werden, steht die Vernetzung zum "Internet der Dinge" im Mittelpunkt. Was bei diesen Zukunftsbildern oft stillschweigend vorausgesetzt wird, ist das Vorhandensein von miniaturisierten, multifunktionellen und autark operierenden Sensor- und Aktorsystemen (so genannte Cyber Physical Systems, CPS), um die Daten aufzunehmen, zu verarbeiten, zu übertragen und auszugeben