The Viennese Warehousers, c. 1700: A Commercial Elite between Trade, State Finance and Industry

In 1515, a group of German, later also Swiss and Italian or Savoyard merchants received permission to settle in Vienna and to deal wholesale during the entire year. These so-called „warehousers“ kept their status of being foreign, mostly protestant, inhabitants of the Habsburg capital for almost three centuries. During the early modern period, the warehousers dominated the Viennese wholesale trade, participated in the early establishment of factories from the late 17th century onwards and acted as Imperial creditors. Even if the warehousers are often mentioned in studies on Viennese and Austrian social and economic history, their commercial activities, business contacts and also family relationships are hardly known. As a pilot study, this article offers a broad overview of the current state of research and the most important primary sources. It discusses the wider context of the warehousers’ business activities (the development of the Austrian lands, Imperial commercial policy, markets in Upper and Lower Austria, and consumption in Vienna and its hinterland). The last chapter of the article provides an introduction to some prominent warehouser companies in the age of mercantilism and offers the earliest complete survey of all warehousers drawing on a list from the year 1725.In 1515, a group of German, later also Swiss and Italian or Savoyard merchants received permission to settle in Vienna and to deal wholesale during the entire year. These so-called „warehousers“ kept their status of being foreign, mostly protestant, inhabitants of the Habsburg capital for almost three centuries. During the early modern period, the warehousers dominated the Viennese wholesale trade, participated in the early establishment of factories from the late 17th century onwards and acted as Imperial creditors. Even if the warehousers are often mentioned in studies on Viennese and Austrian social and economic history, their commercial activities, business contacts and also family relationships are hardly known. As a pilot study, this article offers a broad overview of the current state of research and the most important primary sources. It discusses the wider context of the warehousers’ business activities (the development of the Austrian lands, Imperial commercial policy, markets in Upper and Lower Austria, and consumption in Vienna and its hinterland). The last chapter of the article provides an introduction to some prominent warehouser companies in the age of mercantilism and offers the earliest complete survey of all warehousers drawing on a list from the year 1725

Exfoliation mechanisms of 2D materials and their applications

Due to the strong in-plane but weak out-of-plane bonding, it is relatively easy to separate nanosheets of two-dimensional (2D) materials from their respective bulk crystals. This exfoliation of 2D materials can yield large 2D nanosheets, hundreds of micrometers wide, that can be as thin as one or a few atomic layers thick. However, the underlying physical mechanisms unique to each exfoliation technique can produce a wide distribution of defects, yields, functionalization, lateral sizes, and thicknesses, which can be appropriate for specific end applications. The five most commonly used exfoliation techniques include micromechanical cleavage, ultrasonication, shear exfoliation, ball milling, and electrochemical exfoliation. In this review, we present an overview of the field of 2D material exfoliation and the underlying physical mechanisms with emphasis on progress over the last decade. The beneficial characteristics and shortcomings of each exfoliation process are discussed in the context of their functional properties to guide the selection of the best technique for a given application. Furthermore, an analysis of standard applications of exfoliated 2D nanosheets is presented including their use in energy storage, electronics, lubrication, composite, and structural applications. By providing detailed insight into the underlying exfoliation mechanisms along with the advantages and disadvantages of each technique, this review intends to guide the reader toward the appropriate batch-scale exfoliation techniques for a wide variety of industrial applications

Der Donauhandel* . Quellen zur österreichischen Wirtschaftsgeschichte des 17. und 18. Jahrhunderts

von Peter Rauscher (Wien) und Andrea Serles (Wien) Maut- und Zollregister sowie Rechnungsbücher diver­ser Ämter der größeren Handelsorte zählen zu den in­teressantesten Quellengattungen für die Erforschung der Handelsgeschichte. Sind diese Massenquellen über einen langen Zeitraum erhalten, bilden sie für die ein­zelne Forscherin bzw. den einzelnen Forscher ob ihrer Materialfülle häufig aber auch eine Barriere, die bei be­schränkten zeitlichen und finanziellen Ressourcen nur schwer zu überwind..

Nanomechanics and Tribology of Molybdenum-Disulphide Based Solid Lubricants for Space Applications

Molybdenum-disulphide solid lubricant coatings have an established history of use in space applications. However, limited understanding of their breakdown and failure mechanics has led to premature failure of several systems and missions. In the present study, high-resolution nanomechanical testing techniques are used to examine specific failure mechanics of both pure and co-deposited MoS2 coatings. Fundamental properties such as fracture and shear strength are determined in relation to the nanostructural characteristics of the coatings. It is found that purely nanocrystalline MoS2 shows impeded shearing within the structure compared to partially amorphous MoS2 which therefore increases the friction and wear rates. Furthermore, three state-of-the-art co-deposited coatings are tested under earth to low-earth-orbit specific environments. The newly developed prototype coating is found to outperform the best commercially available coatings under true application-specific conditions. This increased fundamental and application-specific understanding of MoS2 based coatings allows for precision tailoring of MoS2 coatings for reliable performance.M.A.S

Strength measurement and rupture mechanisms of a micron thick nanocrystalline MoS2 coating using AFM based micro-bending tests

International audienceThe present study focuses on the measurement of mechanical properties of a 1.1 μm thick nanocrystalline MoS2 coating deposited by magnetron sputtering with a particular interest in the strength of the coating. Mechanical strength is one of the most important properties to best predict failure of the coating, especially in the case of dry contact lubricated systems in which the coating of interest is often used. An Atomic Force Microscope based micro-bending experiment was developed to measure the rupture strength of MoS2 micro cantilever-beams directly milled in the coating using a Focused Ion Beam. Rupture strength of the MoS2 coatings was measured to be 728 ± 88 MPa. Comparisons with nanoindentation was used to validate the micro-bending technique via the statistically indifferent measurement of the Young’s modulus: 63.1 ± 5.0 GPa and 64.5 ± 4.0 GPa respectively. In depth study of the fractured beam surface and the microstructure of the coating revealed that the surface roughness and the crystallite size can be directly correlated to the rupture pattern. The crack was additionally shown to propagate within the nanocrystalline network existing in the coating. Parallels with the tribological behaviour of the coating are drawn and further confirm the lubrication mechanism described in previous studies

High temperature microtribological studies of MoS2 lubrication for low earth orbit

International audienceMolybdenum disulfide is one of the most common lubricant coatings for spaces ystems but it displays enormous susceptibility to environmental conditions making it hard to predict performance throughout the entire lifetime. The majority of mechanisms for space operate in low Earth orbit where temperatures typically reach 120 ◦C along with exposure to highly reactive atomic oxygen which can be detrimental to lubricant performance. In the present study, a MoS2 lubricant coating is tested using friction force microscopy under different environmental conditions including air and dry nitrogen environments with temperatures ranging from 25 ◦C to 120 ◦C. The increased temperaturewas found to be beneficial for friction behaviour inair up to 100◦C as ambient humidity is removed from the contact, but higher temperatures become detrimental as increased reactivity leads to oxidation. These competing effects resulted in a minimum coefficient of friction at 110◦C in the air environment. The high temperature also increases the wear of the coatings as the intrinsic shear strength decreases with thermal energy which in turn disrupts tribofilm formation leading to increased friction. The run-in duration and magnitude are both found to decrease with temperature as the energy barrier to optimal reconfiguration is reduced. Finally, contextualization of the present findings for mechanisms operating in low earth orbit is discussed

Prehospital and intra-hospital time delays in posterior circulation stroke : results from the Austrian Stroke Unit Registry

Therapeutic effect of recombinant tissue-plasminogen activator (rt-PA) is time dependent. There is limited evidence whether localization of stroke within the posterior circulation (PCS) is associated with a treatment delay. We aimed to analyze within a nationwide multicenter cohort whether duration of pre- and intra-hospital patient management differs between patients with PCS and anterior circulation strokes (ACS). We studied onset-to-door-times (ODT) and door-to-needle-times (DNT) of all patients with acute ischemic stroke (IS) enrolled in the Austrian Stroke Unit Registry according to infarct localization. Classification into PCS and ACS was based on clinical presentation applying the criteria used in the Oxfordshire Community Stroke Project. Relationships between ODT, respectively, DNT and explanatory variables were modeled by multivariate linear regression. Between 2003 and 2015, 71010 patients with IS were enrolled, 11,924 with PCS and 59,086 with ACS. Overall, the ODT was significantly longer in PCS: median (IQR): 170 (25th, 75th: 79,420) min versus 110 (60,240); p < 0.001; this finding held true in multivariable analysis. In 10535 rt-PA-treated patients (1022 PCS/9832 ACS), ODT and DNT were significantly longer among those with PCS: ODT: median: 80 min (55,120) versus 72 (50,110), p < 0.001; DNT: 57 (35.90) versus 45 (30.67), p < 0.001. In the multivariate model, PCS was significantly associated with delay in the DNT. In conclusion, in this large nationwide cohort, patient management was significantly slower in PCS as compared to ACS. Increasing awareness about these delays and further elaboration of the underlying causes may translate into higher proportions of patients with PCS receiving rt-PA.(VLID)349737

Structure dependent wear and shear mechanics of nanostructured MoS2 coatings

International audienceSputter deposited molybdenum disulfide coatings are one of the most common lubricants for extreme environments. However, their performance predictability remains limited by the complexity of van der Waals wear and shear mechanics in bulk materials resulting in unexpected premature failure. In the present study, two nanostructured MoS2 coatings of similar macroscopic properties are shown to exhibit entirely different wear and shear mechanics due to their nanostructure. Friction force microscopy with steel-beaded cantilevers is used to measure the per-cycle evolution of friction, wear, and topography in situ over the lubricant lifetime under an inert nitrogen environment. Molecular dynamics simulations confirm the subsurface structural failure mechanisms of the coatings under shear stress and AFM phase imaging and Raman spectroscopy are used to identify tribofilm formation mechanics. The nanocrystal amorphous composite structure shows improved wear resistance but at the cost of limited stress relaxation which creates high-stress failure and fracture-dominated wear. The purely nanocrystalline coating exhibits lower shear resistance but consistent stress relaxation by van der Waals cleavage and triple junction fracture which results in higher wear rates with predictable abrasion-dominated failure. The contrast in nanoscale performance of the coatings allows for the lubricant nanostructure to be tuned for ideal applications for extreme environments