Electrical Properties of Thin ZrSe3 Films for Device Applications

Measurements of key properties of the two-dimensional transition metal trichalcogenide ZrSe3are reported. The bulk material was created by chemical vapor deposition and subsequently exfoliated to obtain thin films of varying thicknesses. The samples were then characterized by atomic force microscopy measurements and Raman spectroscopy and contacted by e-beam lithography. Electrical measurements give values for the band gap energy of 0.6 eV increasing for thinner samples. Transistor measurements show ZrSe3to be an n-type semiconductor. By looking at several samples with varying thicknesses, it was possible to determine a mean free path of 103 nm for the bulk material which opens the possibility for new electronic devices

The impact of leadership and leadership development in higher education: a review of the literature and evidence

Leadership development and its effectiveness has not been explored in depth empirically, especially across university settings. It is therefore timely that the Leadership Foundation has sought to invest in exploring what is known in the area of the impact of leadership development in higher education settings

Inside/Outside : Post-Synthetic Modification of the Zr-Benzophenonedicarboxylate Metal–Organic Framework

The Zr-based metal–organic framework, Zr-bzpdc-MOF, contains the photoreactive linker molecule benzophenone-4,4'-dicarboxylate (bzpdc) which imparts the possibility for photochemical post-synthetic modification. Upon irradiation with UV light, the keto group of the benzophenone moiety will react with nearly every C-H bond-containing molecule. Within this paper, we further explore the photochemical reactivity of the Zr-bzpdc-MOF, especially with regard to which restrictions govern internal versus external reactions. We show that apart from reactions with C-H bond-containing molecules, the MOF reacts also with water. By studying the reactivity versus linear alcohols we find a clear delineation in that shorter alcohol molecules (up to butanol as a borderline case) react with photoexcited keto groups throughout the whole crystals whereas longer ones react only with surface-standing keto groups. In addition, we show that with the alkanes n-butane to n-octane, the reaction is restricted to the outer surface. We hypothesize that the reactivity of the Zr-bzpdc-MOF versus different reagents depends on the accessibility of the pore system which in turn depends mainly on the size of the reagents and on their polarity. The possibility to direct the post-synthetic modification of the Zr-bzpdc-MOF (selective modification of the whole pore system versus surface modification) gives additional degrees of freedom in the design of this metal–organic framework for shaping and for applications. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

The impact of leadership and leadership development in higher education : a review of the literature and evidence

Leadership development and its effectiveness has not been explored in depth across university settings. Few studies link leadership development programmes to organisational outcomes in Higher Education (HE) or performance assessment exercises, such as the UK Research Excellence Framework (REF). This review explores what is known in the area of the impact of leadership development in HE settings and offers a contribution to further thinking in this field

Experimental and numerical investigations of the development of residual stresses in thermo-mechanically processed Cr-alloyed steel 1.3505

Residual stresses in components are a central issue in almost every manufacturing process, as they influence the performance of the final part. Regarding hot forming processes, there is a great potential for defining a targeted residual stress state, as many adjustment parameters, such as deformation state or temperature profile, are available that influence residual stresses. To ensure appropriate numerical modeling of residual stresses in hot forming processes, comprehensive material characterization and suitable multiscale Finite Element (FE) simulations are required. In this paper, experimental and numerical investigations of thermo-mechanically processed steel alloy 1.3505 (DIN 100Cr6) are presented that serve as a basis for further optimization of numerically modeled residual stresses. For this purpose, cylindrical upsetting tests at high temperature with subsequently cooling of the parts in the media air or water are carried out. Additionally, the process is simulated on the macroscale and compared to the results based on the experimental investigations. Therefore, the experimentally processed specimens are examined regarding the resulting microstructure, distortions, and residual stresses. For the investigation on a smaller scale, a numerical model is set up based on the state-data of the macroscopic simulation and experiments, simulating the transformation of the microstructure using phase-field theory and FE analysis on micro- and meso-scopic level

Leadership development in higher education : a literature review and implications for programme redesign

Leadership development (LD) activity and its effectiveness has not been explored rigorously across changing university settings globally. As Higher Education settings change radically throughout the world, Higher Education professionals are operating in more uncertain environments, and leaders are taking increasingly complex and diverse approaches to their leadership roles. LD activities therefore become important in supporting this highly complex context, yet little is known in the literature about LD and its impact in Higher Education. We examine peer‐reviewed work on LD in Higher Education settings globally to understand what may be learned about its content, processes, outcomes and impact. Our results suggest the current literature is small‐scale, fragmented and often theoretically weak, with many different and coexisting models, approaches and methods, and little consensus on what may be suitable and effective in the Higher Education context. We reflect on this state of play and develop a novel theoretical approach for designing LD activity in Higher Education institutions

Numerische Prozessauslegung zur gezielten Eigenspannungseinstellung in warmmassivumgeformten Bauteilen unter Berücksichtigung von Makro- und Mikroskala

The aim of this work is the adjustment of an advantageous compressive residual stress profile in hot-formed components by intelligent process control with tailored cooling from the forging heat. The feasibility and potential are demonstrated in a hot forming process in which cylindrical specimen with an eccentric hole are formed at 1000 °C and subsequently cooled in water from the forging heat. Previous work shows that tensile residual stresses occur in the specimen formed in this way from the material 1.3505. Using the presented multi-scale FE models, an alternative process variant is analysed in this work, where advantageous compressive residual stresses can be generated instead of tensile residual stresses through tailored cooling from the forming heat in the specimen. The tailored cooling is achieved by partially exposing the specimen to a water-air spray. In this way, the local plastification can be influenced by inhomogeneous strains due to thermal and transformation-induced effects in order to customise the resulting residual stress distribution. The scientific challenge of this work is to generate different residual stresses in the surface of the specimen without changing the geometrical and microstructural properties. It is demonstrated that influencing the residual stresses and even reversing the stress sign is possible using smart process control during cooling.Ziel dieser Arbeit ist die Einstellung eines vorteilhaften Druckeigenspannungsprofils in warmumgeformten Bauteilen durch intelligente Prozessführung mit angepasster Abkühlung aus der Schmiedewärme. Die Machbarkeit und das Potenzial werden an einem Warmumformprozess, bei dem zylindrische Proben mit exzentrischer Bohrung bei 1000 °C umgeformt und anschließend aus der Schmiedewärme im Wasser abgekühlt werden, aufgezeigt. Vorige Arbeiten zeigen, dass sich Zugeigenspannungen in den derartig umgeformten Proben aus dem Material 1.3505 einstellen. Mittels der vorgestellten mehrskaligen FE-Modelle, wird in dieser Arbeit eine alternative Prozessvariante analysiert, mit der vorteilhafte Druckeigenspannungen anstelle von Zugeigenspannungen durch eine angepasste Abkühlung aus der Umformwärme in den Proben erzeugt werden können. Die angepasste Kühlung wird durch eine partielle Beaufschlagung der Proben mit einem Wasser-Luft-Spray erreicht. Auf diese Weise kann die lokale Plastifizierung durch inhomogene Verzerrungen aufgrund thermischer und umwandlungsinduzierter Effekte beeinflusst werden, um letztlich das Eigenspannungsprofil individuell zu gestalten. Die wissenschaftliche Herausforderung dieser Arbeit besteht darin, unterschiedliche Eigenspannungen in der Oberfläche der Proben zu erzeugen, während die geometrischen und mikrostrukturellen Eigenschaften gleichbleiben. Es wird nachgewiesen, dass eine Beeinflussung der Eigenspannungen und sogar die Umkehr des Spannungsvorzeichens allein durch eine geschickte Prozessführung beim Abkühlen möglich ist

Pregnancy Related Health Care Needs in Refugees : A Current Three Center Experience in Europe

Immigration into Europe has reached an all-time high. Provision of coordinated healthcare, especially to refugee women that are at increased risk for adverse pregnancy outcomes, is a challenge for receiving health care systems. Methods: We assessed pregnancy rates and associated primary healthcare needs in three refugee cohorts in Northern Germany during the current crisis. Results: Out of n = 2911 refugees, 18.0% were women of reproductive age, and 9.1% of these were pregnant. Pregnancy was associated with a significant, 3.7-fold increase in primary health care utilization. Language barrier and cultural customs impeded healthcare to some refugee pregnant women. The most common complaints were demand for pregnancy checkup without specific symptoms (48.6%), followed by abdominal pain or urinary tract infections (in 11.4% of cases each). In 4.2% of pregnancies, severe complications such as syphilis or suicide attempts occurred. Discussion: We present data on pregnancy rates and pregnancy associated medical need in three current refugee cohorts upon arrival in Germany. Healthcare providers should be particularly aware of the requirements of pregnant migrants and should adapt primary caretaking strategies accordingly

Atrophy in the Thalamus But Not Cerebellum Is Specific for C9orf72 FTD and ALS Patients - An Atlas-Based Volumetric MRI Study

Background: The neuropathology of patients with frontotemporal dementia (FTD) or amyotrophic lateral sclerosis (ALS) due to a C9orf72 mutation is characterized by two distinct types of characteristic protein depositions containing either TDP-43 or so-called dipeptide repeat proteins that extend beyond frontal and temporal regions. Thalamus and cerebellum seem to be preferentially affected by the dipeptide repeat pathology unique to C9orf72 mutation carriers. Objective: This study aimed to determine if mutation carriers showed an enhanced degree of thalamic and cerebellar atrophy compared to sporadic patients or healthy controls. Methods: Atlas-based volumetry was performed in 13 affected C9orf72 FTD, ALS and FTD/ALS patients, 45 sporadic FTD and FTD/ALS patients and 19 healthy controls. Volumes and laterality indices showing significant differences between mutation carriers and sporadic patients were subjected to binary logistic regression to determine the best predictor of mutation carrier status. Results: Compared to sporadic patients, mutation carriers showed a significant volume reduction of the thalamus, which was most striking in the occipital, temporal and prefrontal subregion of the thalamus. Disease severity measured by mini mental status examination (MMSE) and FTD modified Clinical Dementia Rating Scale Sum of Boxes (FTD-CDR-SOB) significantly correlated with volume reduction in the aforementioned thalamic subregions. No significant atrophy of cerebellar regions could be detected. A logistic regression model using the volume of the prefrontal and the laterality index of the occipital subregion of the thalamus as predictor variables resulted in an area under the curve (AUC) of 0.88 while a model using overall thalamic volume still resulted in an AUC of 0.82. Conclusion: Our data show that thalamic atrophy in C9orf72 mutation carriers goes beyond the expected atrophy in the prefrontal and temporal subregion and is in good agreement with the cortical atrophy pattern described in C9orf72 mutation carriers, indicating a retrograde degeneration of functionally connected regions. Clinical relevance of the detected thalamic atrophy is illustrated by a correlation with disease severity. Furthermore, the findings suggest MRI volumetry of the thalamus to be of high predictive value in differentiating C9orf72 mutation carriers from patients with sporadic FTD