338 research outputs found

    Deposition of copper by plasma-enhanced atomic layer deposition using a novel N-Heterocyclic carbene precursor

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    Two novel N-heterocyclic carbene (NHC)-containing copper(I) amides are reported as atomic layer deposition (ALD) precursors. 1,3-Diisopropyl-imidazolin-2-ylidene copper hexamethyldisilazide (1) and 4,5-dimethyl-1,3-diisopropyl-imidazol-2-ylidene copper hexamethyldisilazide (2) were synthesized and structurally characterized. The thermal behavior of both compounds was studied by thermogravimetric analysis (TGA), and they were both found to be reasonably volatile compounds. Compound 1 had no residual mass in the TGA and showed long-term stability at temperatures as high as 130 °C, while 2 had a residual mass of 7.4%. Copper metal with good resistivity was deposited using 1 by plasma-enhanced atomic layer deposition. The precursor demonstrated self-limiting behavior indicative of ALD, and gave a growth rate of 0.2 Å/cycle. Compound 2 was unsuccessful as an ALD precursor under similar conditions. Density functional theory calculations showed that both compounds adsorb dissociatively onto a growing copper film as long as there is some atomic roughness, via cleavage of the Cu-carbene bond

    Molecular organization of the tear fluid lipid layer

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    The tear fluid protects the corneal epithelium from drying out as well as from invasion by pathogens. It also provides cell nutrients. Similarly to lung surfactant, it is composed of an aqueous phase covered by a lipid layer. Here we describe the molecular organization of the anterior lipid layer of the tear film. Artificial tear fluid lipid layers (ATFLLs) composed of egg yolk phosphatidylcholine (60 mol %), free fatty acids (20 mol %), cholesteryl oleate (10 mol %), and triglycerides (10 mol %) were deposited on the air-water interface and their physico-chemical behavior was compared to egg-yolk phosphatidylcholine monolayers by using Langmuir-film balance techniques, x-ray diffraction, and imaging techniques as well as in silico molecular level simulations. At low surface pressures, ATFLLs were organized at the air-water interface as heterogeneous monomolecular films. Upon compression the ATFLLs collapsed toward the air phase and formed hemispherelike lipid aggregates. This transition was reversible upon relaxation. These results were confirmed by molecular-level simulations of ATFLL, which further provided molecular-scale insight into the molecular distributions inside and dynamics of the tear film. Similar type of behavior is observed in lung surfactant but the folding takes place toward the aqueous phase. The results provide novel information of the function of lipids in the tear fluid

    Ultrathin Oxide Films by Atomic Layer Deposition on Graphene

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    In this paper, a method is presented to create and characterize mechanically robust, free standing, ultrathin, oxide films with controlled, nanometer-scale thickness using Atomic Layer Deposition (ALD) on graphene. Aluminum oxide films were deposited onto suspended graphene membranes using ALD. Subsequent etching of the graphene left pure aluminum oxide films only a few atoms in thickness. A pressurized blister test was used to determine that these ultrathin films have a Young's modulus of 154 \pm 13 GPa. This Young's modulus is comparable to much thicker alumina ALD films. This behavior indicates that these ultrathin two-dimensional films have excellent mechanical integrity. The films are also impermeable to standard gases suggesting they are pinhole-free. These continuous ultrathin films are expected to enable new applications in fields such as thin film coatings, membranes and flexible electronics.Comment: Nano Letters (just accepted

    Die Rolle des Freibergerpferdes im Pferdemarkt Schweiz

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    Das Freiberger Pferd hat wie viele andere vergleichbare lokale, ursprĂŒngliche europĂ€ische Pferderassen mit rĂŒcklĂ€ufigen Bestandes- und Geburtenzahlen sowie einer fehlenden RentabilitĂ€t auf Stufe Produktion zu kĂ€mpfen. Agroscope, Schweizer NationalgestĂŒt SNG, untersuchte im Zuge der Erarbeitung eines Strategierapportes zur Erhaltung der Freibergerrasse die MarktkonformitĂ€t des Freibergerpferdes (FM: franches-montagnes) mittels einer Umfrage bei PferdeeigentĂŒmern sowie ergĂ€nzenden Experteninterviews. Die Ergebnisse lassen den Schluss zu, dass bei einer Mehrheit der befragten PferdeeigentĂŒmer die persönlichen Erwartungen an ein Pferd mit der Beurteilung der QualitĂ€ten und der generellen Wahrnehmung des Freibergerpferdes deckungsgleich sind. Daraus lĂ€sst sich ableiten, dass der FM ĂŒber QualitĂ€ten verfĂŒgt, die im Grundsatz im Freizeitpferdemarkt nachgefragt werden (einfacher Charakter, Polyvalenz, Robustheit, Gesundheit). Das Image des Markenbildes FM ist bei den nicht FM-Besitzern deutlich weniger positiv als bei den FM-Besitzern. Die Ergebnisse der Umfrage sowie der Experteninterviews zeigten, dass vor allem Anstrengungen zur Verbesserung der Vermarktung und des Images notwendig sind, um einen besseren Absatz von Freibergerpferden zu gewĂ€hrleisten und damit auch langfristig einen Anstieg der Geburten zu erreichen

    Digital transformation, for better or worse: a critical multi-level research agenda

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    For better or worse, digital technologies are reshaping everything, from customer behaviors and expectations to organizational and manufacturing systems, business models, markets, and ultimately society. To understand this overarching transformation, this paper extends the previous literature which has focused mostly on the organizational level by developing a multi‐level research agenda for digital transformation (DT). In this regard, we propose an extended definition of DT as “a socioeconomic change across individuals, organizations, ecosystems, and societies that are shaped by the adoption and utilization of digital technologies.” We suggest four lenses to interpret the DT phenomenon: individuals (utilizing and adopting digital technologies), organizations (strategizing and coordinating both internal and external transformation), ecosystems (harnessing digital technologies in governance and co‐producing value propositions), and geopolitical frameworks (regulating the environments in which individuals and organizations are embedded). Based on these lenses, we build a multi‐level research agenda at the intersection between the bright and dark sides of DT and introduce the PIAI framework, which captures a process of perception, interpretation, and action that ultimately leads to possible impact. The PIAI framework identifies a critical research agenda consisting of a non‐exhaustive list of topics that can assist researchers to deepen their understanding of the DT phenomenon and provide guidance to managers and policymakers when making strategic decisions that seek to shape and guide the DT.</jats:p

    Designing Value-Oriented Service Systems by Value Map

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    In this paper, we introduce a problem structuring method (PSM) called “Value Map”. Value Map is an extension to the Supplier Adopter Relationship Diagram in the Systemic Enterprise Architecture Method (SEAM). Value Map assists in understanding, analysis and design of value creation and capture in service systems. We illustrate the applicability of the Value Map by modeling value creation and capture in the service system of a social networking company called Webdoc. To validate the usefulness of the Value Map, we conducted an empirical study in which we also compared the Value Map to Business Model Canvas, one of the most established methods in business model design. The results of the study show that the Value Map helps business practitioners in understanding and analyzing customer value, customer value creation, and the value capture processes. We conducted an empirical study in which we assessed the usefulness of Value Map and compared it with Business Model Canvas, one of the most established methods in business model design. The results of the study show that the Value Map helps business practitioners to understand and analyze customer value, customer value creation, and the value capture processes

    Atomic Layer Deposition of 2D Metal Dichalcogenides for Electronics, Catalysis, Energy Storage, and Beyond

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    2D transition metal dichalcogenides (TMDCs) are among the most exciting materials of today. Their layered crystal structures result in unique and useful electronic, optical, catalytic, and quantum properties. To realize the technological potential of TMDCs, methods depositing uniform films of controlled thickness at low temperatures in a highly controllable, scalable, and repeatable manner are needed. Atomic layer deposition (ALD) is a chemical gas-phase thin film deposition method capable of meeting these challenges. In this review, the applications evaluated for ALD TMDCs are systematically examined, including electronics and optoelectonics, electrocatalysis and photocatalysis, energy storage, lubrication, plasmonics, solar cells, and photonics. This review focuses on understanding the interplay between ALD precursors and deposition conditions, the resulting film characteristics such as thickness, crystallinity, and morphology, and ultimately device performance. Through rational choice of precursors and conditions, ALD is observed to exhibit potential to meet the varying requirements of widely different applications. Beyond the current state of ALD TMDCs, the future prospects, opportunities, and challenges in different applications are discussed. The authors hope that the review aids in bringing together experts in the fields of ALD, TMDCs, and various applications to eventually realize industrial applications of ALD TMDCs.Peer reviewe
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