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Influence of Free Layer Surface Roughness on Tunnel Magnetoresistance in 300 mm CMOS-compatible MTJ Stacks
No full textThe magnetic tunnel junction (MTJ) is a highly versatile device widely used in magnetoresistive random-access memory (MRAM), magnetic sensors and prospective as a read device in racetrack memory. Tuning the MTJ stack to match the desired properties, such as tunnel magnetoresistance (TMR), magnetic anisotropy or coercive field of the free layer, requires careful optimization of the deposition parameters as well as precise thickness control. Here, the deposition of individual layers in a wedged manner across 300 mm wafers is proposed to engineer the thicknesses within the stack more efficiently. Furthermore, this technique provides detailed insights into effects related to surface roughness, magnetic anisotropy and TMR
A Comparative Evaluation of Requirement Template Systems (Summary)
No full text4748Our publication at the 31th International Requirements Engineering Conference 2023 concerns the multiple semi-formal syntax templates for natural language requirements, that foster to reduce ambiguity while preserving readability. Yet, existing studies on their effectiveness do not allow to systematically investigate quality benefits and compare different notations. We strive for a comparative benchmark and evaluation of template systems to support practitioners in selecting template systems and enable researchers to work on pinpoint improvements and domain-specific adaptions. We conduct a comparative experiment with a control group of free-text requirements and treatment groups of their variants following different templates. We compare effects on metrics systematically derived from quality guidelines. We present a benchmark consisting of a systematically derived metric suite over seven relevant quality categories and a dataset of 1764 requirements, comprising 249 free-text forms from five projects and variants in five template systems. We evaluate effects in comparison to free text. Except for one template system, all have solely positive effects in all categories. The proposed benchmark enables the identification of the relative strengths and weaknesses of different template systems. However, overall effect sizes are relatively similar. Yet, the results show that templates can generally improve quality compared to free text
Gripoptimierung weicher Polymeroberflächen am Beispiel des Handballs
No full textEin umgangssprachlich "guter Grip" ist an vielen Stellen des täglichen Lebens grundlegende Voraussetzung für eine sichere und zuverlässige Handhabung von Geräten und Gegenständen. Die zur Steigerung der Griffigkeit häufig genutzten weichen Polymeroberflächen ergeben zusammen mit der menschlichen Haut und den spezifischen Umgebungsbedingungen tribologischer Systeme, welche sich durch viele Besonderheiten, spezielle Anforderungen und einen hohen Grad an Komplexität auszeichnen. Diese werden zusammen mit aktuellen Herausforderungen am Beispiel des Handballsports vorgestellt. Dazu wird ein allgemeiner Überblick gegeben und mit Ergebnissen aus eigenen Forschungsprojekten untersetzt
Influence of Increased Fe, Cu, and Zn Concentrations on Phase Formation in Aluminum A356 (AlSi7Mg0.3) Alloy
No full text234240The production of Al alloysAl alloys from end-of-life (EoL) scrap is being accompanied by increased Fe-, Cu-, and Zn content. The influence of these elements was evaluated with special emphasis on phase formationPhase formation, via the application of CALPHAD methodsMethod to address the questions if a defined heat treatmentHeat treatment can compensate for the formationFormation of Al9Si2Fe2 and Al2Cu, how the combinations of such elements influence the formationFormation of detrimental phases and whether a combined approach of heat treatmentHeat treatment and alloy designAlloy design is valid for higher amounts of Fe, Cu, and Zn in primary-based alloysAlloys. It was found that Cu and Zn up to established limits in common supply specifications are less detrimental to alloyAlloys properties. Fe was found to be manageable, which is in good agreement with previous findings
AlScN Based Piezoelectrically Driven Quasi-Static MEMS Scanners with Large Field of View and Selectable Regions of Interest
No full text435438AlScN driven quasi-static MEMS scanners demonstrate exceptional actuation force, precision and movement linearity, making them ideal for applications ranging from LiDAR to quantum computing. We investigate the separation of the piezoelectric layer on each actuator into a main and a sub segment for sensing and actuation purposes. Raw data shows a good sensitivity of up to 8 mV/°TOSA in resonant drive without data procession. When driving the main and sub segment quasi-statically the segmentation yields an 11 % performance increase despite reduced actuation area. Additionally, quasi-static deflections of 30° TOSA and complex scan patterns such as a controllable ROI scan can be performed to extend the system operation capabilities in applications like LiDAR or space communication
Mechanistic profiling and optimized production of Altenusin, a fungal carboxy-biphenyl scaffold for tyrosinase inhibition
No full text98349850Tyrosinase is a binuclear copper oxidase central to melanogenesis and food browning and is a major target for depigmenting and anti-browning agents. Here we evaluate Altenusin, a fungal carboxy-biphenyl polyketide, as a tyrosinase-inhibitor scaffold by combining structure-based screening, enhanced fermentation and mechanistic enzymology. Docking against the mushroom tyrosinase Agaricus bisporus PPO3 (AbPPO3) highlighted Altenusin as a presumed dicopper-site binder, and genome mining of the producer strain revealed a polyketide synthase gene cluster consistent with its biosynthesis. Fermentation optimization and bioreactor transfer increased Altenusin titers up to 0.254 ± 0.022 g L-1. In vitro, Altenusin inhibited in a substrate-dependent manner, with IC50 values of 0.381 ± 0.002 mM (L-tyrosine) and 0.162 ± 0.023 mM (L-DOPA); kinetic analysis indicated competitive monophenolase inhibition and mixed-type diphenolase inhibition. Altenusin also showed strong radical-scavenging and copper-reducing activity, moderate Cu2+ chelation and a narrow cytotoxicity window in HepG2 cells (48 h, CC50: 0.093 mM). Overall, these data define Altenusin as a biotechnologically tractable starting point for fungal carboxy-biphenyl inhibitor discovery.161
Deep Learning-Based Postprocessing to Enhance Subseasonal Soil Moisture Forecasts Over Europe
No full textAccurate forecasts on subseasonal (S2S) timescales are essential for the preparation and mitigation of the impacts of high-impact events, such as flash droughts. To improve the accuracy of soil moisture forecasts—a critical factor in identifying flash droughts—we present a hybrid modeling framework that combines dynamical forecasts from the European Centre for Medium-Range Weather Forecasts with deep learning (DL) models. This approach not only corrects biases in numerical weather prediction models but also improves spatial resolution, increasing the accuracy of S2S forecasts. By using deterministic inputs, such as the ensemble mean and spread, we further assess the uncertainty of forecasts through dropout neural networks via Monte Carlo sampling. Our results demonstrate that the DL models outperform baseline methods, offering skillful S2S forecasts of soil moisture. This advanced hybrid framework provides more accurate soil moisture predictions, ultimately supporting improved strategies for managing and mitigating the impacts of flash droughts.2
Functionalising silk hydrogels with hetero- and homotypic nanoparticles
No full text35253535Despite many reports detailing silk hydrogels, the development of composite silk hydrogels with homotypic and heterotypic silk nanoparticles and their impact on material mechanics and biology have remained largely unexplored. We hypothesise that the inclusion of nanoparticles into silk-based hydrogels enables the formation of homotropic and heterotropic material assemblies. The aim was to explore how well these systems allow tuning of mechanics and cell adhesion to ultimately control the cell-material interface. We utilised nonporous silica nanoparticles as a standard reference and compared them to nanoparticles derived from Bombyx mori silk and Antheraea mylitta (tasar) silk (approximately 100-150 nm in size). Initially, physically cross-linked B. mori silk hydrogels were prepared containing silica, B. mori silk nanoparticles, or tasar silk nanoparticles at concentrations of either 0.05% or 0.5% (w/v). The initial modulus (stiffness) of these nanoparticle-functionalised silk hydrogels was similar. Stress relaxation was substantially faster for nanoparticle-modified silk hydrogels than for unmodified control hydrogels. Increasing the concentrations of B. mori silk and silica nanoparticles slowed stress relaxation, while the opposite trend was observed for hydrogels modified with tasar nanoparticles. Cell attachment was similar for all hydrogels, but proliferation during the initial 24 h was significantly improved with the nanoparticle-modified hydrogels. Overall, this study demonstrates the manufacture and utilisation of homotropic and heterotropic silk hydrogels.14
Design of a Charging Station for Electric Vehicles Based on a Photovoltaic-Biodiesel Hybrid Renewable Energy System Combined with Battery Storage
No full textThe rapid deployment of electric vehicles (EVs) in Jordan requires massive efforts to prepare the infrastructures that serve the transportation sector. The lack of EV charging stations is the major obstacle that faces EV drivers. Utilizing renewable energy in EV charging stations contributes to the spread of these stations. Renewable energy technologies are environmentally friendly as they mitigate greenhouse gases that cause the global warming phenomenon. In this paper, an EV charging station, based on a PV-biodiesel-battery hybrid system, is investigated. The importance of this article is to discuss the hybrid system of PV and waste vegetable oil (WVO) along with storage that applies the maximum reliability supply, having an environmentally friendly supply and achieving the lowest energy cost of charging. This station is designed based on renewable and WVO utilization. In fact, WVO, coming from restaurants, is exploited to produce electricity by a diesel generator through direct burning after converting it into biodiesel. The capacity of each station is 14 cars/day with a medium-speed charger of 7 kW. The system is simulated and optimized using iHOGA software where multiobjective optimization is applied to achieve the minimum net present cost (NPC) and CO2 emissions considering three cases, PV-diesel, PV-biodiesel, and PV-WVO, all with battery-hybrid system. These values for the EV charging station that uses the PV-biodiesel-battery hybrid system are 624408 € and 15.4 tons/year, respectively. The corresponding values are 781473 € and 15.14 tons/year and 615310 € and 18.84 tons/year for the systems that work with diesel and WVO, respectively, and energy cost is achieved in best solution to be 0.11 Euro/kWh. Simulation results show that the proposed technique led to enhanced operational efficiency in terms of both NPC and annual CO2 emissions.202