Knowledge and information awareness for initiating transactive memory system processes of computer-supported collaborating ad hoc groups

This paper presents an innovative approach for initiating processes of a transactive memory system in newly formed groups of experts collaborating computer-supported in a complex problem-solving task. Our empirical study compared 15 experimental and 15 control groups, each consisting of triads. In the experimental condition, the triads were provided with a tool for fostering knowledge and information awareness, that is, being informed about the knowledge and the underlying information of the collaboration partners in form of digital concept maps. In the control condition, the groups had no access to this tool. Results confirmed the potential of the tool to initiate processes of a transactive memory system: shared agreement of the knowledge of the other group members’ knowledge proved to influence group performance positively. In addition, previous findings of the tool’s potential to establish knowledge and information awareness and to augment group performance could be replicated. However, the postulated mediating effect of processes of a transactive memory system concerning the impact of knowledge and information awareness on group performance did not reach statistical significance. Aspects for future studies and implications of these findings regarding their practical implementation, for example, in teams of organizations, are discussed.     

The GHG balance of biofuels taking into account land use change

The contribution of biofuels to the saving of greenhouse gas (GHG) emissions has recently been questioned because of emissions resulting from land use change (LUC) for bioenergy feedstock production. We investigate how the inclusion of the carbon effect of LUC into the carbon accounting framework, as scheduled by the European Commission, impacts on land use choices for an expanding biofuel feedstock production. We first illustrate the change in the carbon balances of various biofuels, using methodology and data from the IPCC Guidelines for National Greenhouse Gas Inventories. It becomes apparent that the conversion of natural land, apart from grassy savannahs, impedes meeting the EU's 35% minimum emissions reduction target for biofuels. We show that the current accounting method mainly promotes biofuel feedstock production on former cropland, thus increasing the competition between food and fuel production on the currently available cropland area. We further discuss whether it is profitable to use degraded land for commercial bioenergy production as requested by the European Commission to avoid undesirable LUC and conclude that the current regulation provides little incentive to use such land. The exclusive consideration of LUC for bioenergy production minimizes direct LUC at the expense of increasing indirect LUC.     

Metall-Recycling mittels Biohydrometallurgie

Biohydrometallurgy as a section of hydrometallurgy uses specific metabolic capabilities of microorganisms for metal extraction. Biomining is the application of bioleaching for metal extraction from sulfide ores. For recycling, i.e., metal extraction from waste and industrial residues, there are no biohydrometallurgical technologies yet, but promising laboratory studies on metal extraction from solids. In this review article, these are summarized, and perspectives are shown.     

Cardiac- versus diaphragm-based respiratory navigation for proton spectroscopy of the heart

Magnetic Resonance Materials in Physics, Biology and Medicine - To study inter-individual differences of the relation between diaphragm and heart motion, the objective of the present study was to...     

Einfluss der elastischen Nachgiebigkeit auf die Kraft beim tauchenden Kegelradschleifen

Forschung im Ingenieurwesen - Aufgrund steigender Anforderungen an den Wirkungsgrad und die Geräuschanregung von Zahnradgetrieben ist die Hartbearbeitung von Zahnrädern für viele...     

PPAR-Gamma Activation May Inhibit the In Vivo Degeneration of Bioprosthetic Aortic and Aortic Valve Grafts under Diabetic Conditions

Background: We aimed to examine the anti-calcification and anti-inflammatory effects of pioglitazone as a PPAR-gamma agonist on bioprosthetic-valve-bearing aortic grafts in a rat model of diabetes mellitus (DM). Methods: DM was induced in male Wistar rats by high-fat diet with an intraperitoneal streptozotocin (STZ) injection. The experimental group received additional pioglitazone, and controls received normal chow without STZ (n = 20 each group). Cryopreserved aortic donor grafts including the aortic valve were analyzed after 4 weeks and 12 weeks in vivo for analysis of calcific bioprosthetic degeneration. Results: DM led to a significant media proliferation at 4 weeks. The additional administration of pioglitazone significantly increased circulating adiponectin levels and significantly reduced media thickness at 4 and 12 weeks, respectively (p = 0.0002 and p = 0.0107, respectively). Graft media calcification was highly significantly inhibited by pioglitazone after 12 weeks (p = 0.0079). Gene-expression analysis revealed a significant reduction in relevant chondro-osteogenic markers osteopontin and RUNX-2 by pioglitazone at 4 weeks. Conclusions: Under diabetic conditions, pioglitazone leads to elevated circulating levels of adiponectin and to an inhibition of bioprosthetic graft degeneration, including lower expression of chondro-osteogenic genes, decreased media proliferation, and inhibited graft calcification in a small-animal model of DM.     

Wear Performance of Dental Materials: A Comparison of Substructure Ceramics,Veneering Ceramics,and Non‐Precious Alloys

The aim of this in vitro study was to compare the two‐body wear resistance of different dental ceramics and non‐precious alloys. Two‐body wear tests were performed in a chewing simulator with steatite antagonists. A pin‐on‐block design with a vertical load of 50 N for 1.2 × 10⁵ cycles (f = 1.6 Hz; lateral movement: 1 mm, mouth opening: 2 mm) was used for the wear test. Surface roughness R_a (SP6, Perthen‐Feinprüf, G) and wear depth were determined using a 3D‐Profilometer (Laserscan 3D, Willytec, G). Scanning electron microscopy (Quanta FEG 400, FEI, NL) was applied for evaluating wear performance of both, materials and antagonists. Statistics: one‐way ANOVA (α = 0.05). The in vitro wear test showed that the wear performance of dental materials is strongly influenced by the type of material (ceramic, zirconia, or alloy). Zirconia and alloy provided low wear in contrast to glass‐ceramic systems. In contradiction to common expectations, hard zirconia and alloy systems showed even lower antagonistic wear than glass‐ceramics.     

From Lithium-Metal toward Anode-Free Solid-State Batteries: Current Developments,Issues, and Challenges

The development of rechargeable batteries with high-energy density is critical for future decarbonization of transportation. Anode-free Li-ion batteries, using a bare current collector at the anode side without any excess of Li, provide the highest volumetric energy density ( > 1500 Wh L⁻¹) among all possible cell configurations. Furthermore, elimination of the anode material coating reduces material consumption and greatly simplifies cell production, which in turn lowers costs. Although significant progress has been made recently by the application of modified current collectors, optimized cycling parameters and improved liquid electrolytes, insufficient efficiencies, and dendritic growth during lithium plating lead to poor cycle life of typically less than 100 cycles as well as safety issues. Alternatively, very recent studies have demonstrated anode-free solid-state batteries that combine the benefits of high energy anode-free cell configuration and solid-state systems with high safety, exceeding 1000 cycles. This review provides an overview of recent developments toward anode-free solid-state batteries and highlights the current issues and challenges in this nascent field. It is concluded that, although major challenges remain at the present, the lessons learned in the fields of liquid electrolytes and solid-state lithium metal batteries can accelerate the development of anode-free solid-state batteries of practical relevance.