Controlling mechanical and physical properties of Al-Si alloys by controlling grain size through grain refinement and electromagnetic stirring

The present study concerns the influence of a travelling magnetic field (TMF) on the hardness, tensile strength and electrical conductivity of directionally solidified grain-refined and non-refined Al-7 wt.% Si alloys. Upwards and downwards travelling fields have been applied to force convection within the solidifying melt. Modifications of the examined physical and mechanical properties depend on the formation of a fine equiaxed structure caused by both the addition of grain refining AlTi5B1-particles and by electromagnetic stirring as well. Electromagnetic stirring without grain refining particles leads to an increase in tensile strength. The addition of grain refiners into the melt leads to the highest reduction of the mean grain size and results in a decrease in electrical conductivity. A melt stirring by a sufficiently high magnetic field provides a homogeneous grain size distribution in the sample volume which impacts the distribution of hardness, tensile strength and electrical conductivity

Ultra-thin Materials from Atomic Layer Deposition for Microbolometers

This research focuses on the incorporation of atomic layer deposition (ALD) materials into microbolometer devices for infrared (IR) imaging. Microbolometers are suspended micro-electromechanical (MEMS) devices, which respond electrically to absorbed IR radiation. By minimizing the heat capacity (thermal mass) of these devices, their performance may be substantially improved. Thus, implementing ultra-thin freestanding ALD materials into microbolometer devices will offer a substantial reduction in the overall heat capacity of the device. A novel nanofabrication method is developed to produce robust ultra-thin suspended structures from ALD generated materials including W, Ru and Al2O3. Unique aspects of ALD such as high conformality offer the ability to create 3-dimensional structures with mechanical reinforcement. Additionally, the ability to tune residual stresses via atomically precise thickness control enables the fabrication of flat suspended structures. Since microbolometer elements are electro-thermally active, the electro-thermal properties of ultra-thin ALD W, Ru and Al2O3 are investigated. Several distinct deviations from bulk electro-thermal properties of resistivity, temperature coefficient of resistance, thermal conductivity and specific heat capacity are identified and interpreted with traditional nanoscale transport modeling and theory. For example, for ALD W, the electrical resistivity is increased by up to 99%, thermal conductivity is reduced by up to 91% and specific heat capacity increased 70% from bulk. Finally, the developed ALD nano-fabrication process and measured ALD material properties are combined to fabricate an industrial level, state-of-the-art microbolometer pixel structure with 1.4X performance improvement. Further microbolomter performance enhancements based on the developed nanofabrication methods and electro-thermal measurements are discussed

Role of Natural Binding Proteins in Therapy and Diagnostics

This review systematically investigates the critical role of natural binding proteins (NBPs), encompassing DNA-, RNA-, carbohydrate-, fatty acid-, and chitin-binding proteins, in the realms of oncology and diagnostics. In an era where cancer continues to pose significant challenges to healthcare systems worldwide, the innovative exploration of NBPs offers a promising frontier for advancing both the diagnostic accuracy and therapeutic efficacy of cancer management strategies. This manuscript provides an in-depth examination of the unique mechanisms by which NBPs interact with specific molecular targets, highlighting their potential to revolutionize cancer diagnostics and therapy. Furthermore, it discusses the burgeoning research on aptamers, demonstrating their utility as ‘nucleic acid antibodies’ for targeted therapy and precision diagnostics. Despite the promising applications of NBPs and aptamers in enhancing early cancer detection and developing personalized treatment protocols, this review identifies a critical knowledge gap: the need for comprehensive studies to understand the diverse functionalities and therapeutic potentials of NBPs across different cancer types and diagnostic scenarios. By bridging this gap, this manuscript underscores the importance of NBPs and aptamers in paving the way for next-generation diagnostics and targeted cancer treatments

Mechanical properties of metal matrix composites based on TRIP steel and ZrO2 ceramic foams

AbstractThis study presents the mechanical behaviour of newly developed metal matrix composites (MMCs) in terms of compression and fatigue properties. The matrix of the MMCs consists of a high-alloyed metastable austenitic cast steel, which shows the TRIP-effect (TRIP-TRansformation Induced Plasticity). As reinforcing phase MgO partially stabilized ZrO2 is used which can also undergo a martensitic phase transformation. The samples were produced by infiltration of the cast steel into open foam structures made of ZrO2 with porosities of 30 and 50 ppi. The fatigue properties were investigated under total-strain and stress control. The martensitic phase transformation of the austen-itic steel matrix was investigated using a feritscope sensor. © 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM1