Resolving hydrogen atoms at metal-metal hydride interfaces

Hydrogen as a fuel can be stored safely with high volumetric density in metals. It can, however, also be detrimental to metals causing embrittlement. Understanding fundamental behavior of hydrogen at atomic scale is key to improve the properties of metal-metal hydride systems. However, currently, there is no robust technique capable of visualizing hydrogen atoms. Here, we demonstrate that hydrogen atoms can be imaged unprecedentedly with integrated differential phase contrast, a recently developed technique performed in a scanning transmission electron microscope. Images of the titanium-titanium monohydride interface reveal remarkable stability of the hydride phase, originating from the interplay between compressive stress and interfacial coherence. We also uncovered, thirty years after three models were proposed, which one describes the position of the hydrogen atoms with respect to the interface. Our work enables novel research on hydrides and is extendable to all materials containing light and heavy elements, including oxides, nitrides, carbides and borides

Crossing Central Europe

This volume studies elements of Austro-Hungarian or Central European culture that were common across linguistic, national, and ethnic communities, and shows how some of these commonalities survived or were transformed by the turmoil of the 20th century: two world wars, a major depression between the wars, Stalinism and the Iron Curtain

Health-related quality of life outcomes after kidney transplantation

With the improvements in short and long term graft and patient survival after renal transplantation over the last two decades Health-Related Quality of Life (HRQL) is becoming an important additional outcome parameter. Global and disease specific instruments are available to evaluate objective and subjective QOL. Among the most popular global tools is the SF-36, examples of disease specific instruments are the Kidney Transplant Questionnaire (KTQ), the Kidney Disease Questionnaire (KDQ) and the Kidney Disease-Quality of Life (KDQOL). It is generally accepted that HRQL improves dramatically after successful renal transplantation compared to patients maintained on dialysis treatment but listed for a transplant. It is less clear however which immunosuppressive regimen confers the best QOL. Only few studies compared the different regimens in terms of QOL outcomes. Although limited in number, these studies seem to favour non-cyclosporine based protocols. The main differences that could be observed between patients on cyclosporine versus tacrolimus or sirolimus therapy concern the domains of appearance and fatigue. This may be explained by two common adverse effects occurring under cyclosporine therapy, gingival hyperplasia and hair growth. Another more frequently occurring side effect under calcineurin inhibitor therapy is tremor, which may favour CNI free protocols. This hypothesis, however, has not been formally evaluated in a randomised trial using HRQL measurements. In summary HRQL is becoming more of an issue after renal transplantation. Whether a specific immunosuppressive protocol is superior to others in terms of HRQL remains to be determined

Identification of factors limiting fruit set in tomato (Solanum lycopersicum L.) with the aim of genetic improvement of heat tolerance

[no abstract

Grenzüberschreitungen : Kulturelle Transfers als aktuelle Forschungsperspektive

info:eu-repo/semantics/publishe

[...] versucht ihr wirklich euch zu integrieren oder ist das nur so dahergesagt?

Die Arbeit ist an den Schnittstellen der anthropologischen Migrationsforschung, der Soziolinguistik und der Biografieforschung angelegt und handelt davon, wie gesellschaftliche und politische Diskurse auf den (Deutsch-)Spracherwerb von Frauen, die vor mindestens 5 Jahren nach Wien migriert sind, wirken

Die Bewertung von Siedlungsstrukturen des verdichteten Wohnbaus im urbanen Umfeld

Die vorliegende Arbeit befasst sich mit der Bewertung unterschiedlicher Siedlungsstrukturen aus dem urbanen Umfeld hinsichtlich der allgemeinen gefühlsmäßigen Beurteilung, der erwarteten Befriedigung von Wohnbedürfnissen und der erwarteten nachbarschaftlichen Beziehungen. Dazu wurden vier verschiedene Struktururen (kreisförmige, reihenförmige, verstreute und offen-kreisförmige Siedlungen) mit jeweils zwei Bildern untersucht. Das Bildmaterial besteht aus acht Luftbildaufnahmen von Mehrfamilienhaus-Siedlungen aus österreichischen Hauptstädten, welche in einer Online-Untersuchung 215 Personen vorgegeben wurden. Die wichtigsten Ergebnisse der Studie beziehen sich auf Gemeinsamkeiten in den Beurteilungen bei Siedlungen gleicher Struktur. So etwa werden in reihenförmigen Siedlungen wenig Möglichkeiten zur Selbstverwirklichung erwartet, sie scheinen für Kinder nicht so gut geeignet zu sein und es wird eher wenig nachbarschaftliche Unterstützung und Hilfe erwartet. Siedlungen mit verstreuter Struktur erwecken einen aufgelockerten und zugänglichen Eindruck und sie werden als funktional angesehen. Kreisförmige Siedlungen wirken auf die Beurteiler eher abwechslungsreich und verbinden. Die Siedlungen mit offener Kreisstruktur werden insgesamt am besten bewertet. Sie gefallen besonders gut, werden als abwechslungsreich, verbindend und funktional eingestuft, scheinen für Kinder gut geeignet zu sein und es wird viel Unterstützung und Hilfe durch die Nachbarn erwartet. Hinsichtlich der nachbarschaftlichen Beziehungen werden die offen-kreisförmigen Siedlungen und eine der kreisförmigen Siedlungen generell am positivsten bewertet. Dies bestätigt auch Annahmen aus der Literatur, wodurch Siedlungen mit semiprivaten Übergangszonen, welche ästhetisch und ansprechend wirken, eine optische Einheit nach Außen bilden, ausreichend öffentlichen Raum für Kontakte bieten und über einen gemeinsamen Innenhof verfügen, nachbarschaftliche Beziehungen unterstützen

Real space imaging of hydrogen at a metal - metal hydride interface

Hydrogen as a prospective fuel can be stored safely with high volumetric density in metals. It can, however, also be detrimental to metals causing embrittlement. For a better understanding of these metal-metal hydride systems, and in particular their interfaces, real-space imaging of hydrogen with atomic resolution is required. However, hydrogen has not been imaged before at an interface. Moreover, to date, a robust technique that is capable to do such light-element imaging has not been demonstrated. Here, we show that integrated Differential Phase Contrast (iDPC), a recently developed imaging technique performed in an aberration corrected scanning transmission electron microscope, has this capability. Atomically sharp interfaces between hexagonal close-packed titanium and face-centered tetragonal titanium monohydride have been imaged, unambiguously resolving the hydrogen columns. Exploiting the fact that this monohydride has two types of columns with identical surrounding of the host Ti atom we have, 30 years after they were first proposed, finally resolved which one of the proposed structural models holds for the interface. Using both experimental and simulated images, we compare the iDPC technique with the currently more common annular bright field (ABF) technique, showing that iDPC is superior regarding complicating wave interference effects that may lead to erroneous detection of light element columns

Real space imaging of hydrogen at a metal - metal hydride interface

Hydrogen as a prospective fuel can be stored safely with high volumetric density in metals. It can, however, also be detrimental to metals causing embrittlement. For a better understanding of these metal-metal hydride systems, and in particular their interfaces, real-space imaging of hydrogen with atomic resolution is required. However, hydrogen has not been imaged before at an interface. Moreover, to date, a robust technique that is capable to do such light-element imaging has not been demonstrated. Here, we show that integrated Differential Phase Contrast (iDPC), a recently developed imaging technique performed in an aberration corrected scanning transmission electron microscope, has this capability. Atomically sharp interfaces between hexagonal close-packed titanium and face-centered tetragonal titanium monohydride have been imaged, unambiguously resolving the hydrogen columns. Exploiting the fact that this monohydride has two types of columns with identical surrounding of the host Ti atom we have, 30 years after they were first proposed, finally resolved which one of the proposed structural models holds for the interface. Using both experimental and simulated images, we compare the iDPC technique with the currently more common annular bright field (ABF) technique, showing that iDPC is superior regarding complicating wave interference effects that may lead to erroneous detection of light element columns