A5076824806- Additive Manufacturing Materials and Processes
- Advanced Welding Techniques Analysis
- Aluminum Alloys Composites Properties
- Additive Manufacturing and 3D Printing Technologies
- Global Peace and Security Dynamics
- MXene and MAX Phase Materials
- Nuclear Materials and Properties
- Welding Techniques and Residual Stresses
- Catalytic C–H Functionalization Methods
- South African History and Culture
- Nuclear materials and radiation effects
- Synthesis and Catalytic Reactions
- Political Conflict and Governance
- International Development and Aid
- Legal Issues in South Africa
- Radioactive element chemistry and processing
- Global Political and Social Dynamics
- Phenothiazines and Benzothiazines Synthesis and Activities
- Aluminum Alloy Microstructure Properties
- International Arbitration and Investment Law
- Geological and Geochemical Analysis
- Cellular and Composite Structures
- Microstructure and mechanical properties
- ICT Impact and Policies
- Law, logistics, and international trade
Lawrence Livermore National Laboratory
2023-2025
Virginia Tech
2018-2024
Port Macquarie Base Hospital
2019
GlaxoSmithKline (United Kingdom)
2017-2018
University of Strathclyde
2017-2018
North Hertfordshire College
2018
University of North Carolina at Greensboro
1991-2016
The repair of high strength, performance 7075 aluminum alloy is essential for a broad range aerospace and defense applications. However, it challenging to implement using traditional fusion welding-based approaches, owing hot cracking void formation during solidification. Here, the use an emerging solid-state additive manufacturing technology, friction stir deposition, explored volume damages such as through -holes grooves in alloy. Three experiments have been conducted: double through-hole...
Owing to the occurrence of hot cracking during solidification and vaporization solute elements melting, beam-based additive manufacturing has encountered serious problems in printing high-strength, nonweldable Al alloys. After aging, mechanical properties these alloys are often substantially inferior their wrought alloy counterparts. Here, a deformation-based process is used for high-strength 7075 (i.e., AA7075), wherein frictional heating leveraged enable rapid plastic deformation. The...
A new and efficient process to access β-functionalisation of cyclic amines<italic>via</italic>a mild oxidative β-sulfonylation.
A metal-free strategy for the formation of lactams via selective oxidation cyclic secondary and tertiary amines is described. Molecular iodine facilitates both chemoselective regioselective C-H bonds directly adjacent to a amine. The mild conditions, functional group tolerance, substrate scope are demonstrated using suite diverse small molecule amines, including clinically approved drug scaffolds.
ConspectusStructural metal components play a vital role in broad range of industries, from aerospace and automotive to infrastructure defense. In service, these can experience substantial wear, thermal fatigue, erosion, corrosion, or chemical reactions, resulting significant surface even volumetric damages. Replacement is often energy-intensive economically impractical. Structural repair, which aims restore the original geometry while enabling good mechanical performance postrepair, offset...
Given the challenges in feed material supply and quality control, metal additive manufacturing has rarely been implemented austere environments, especially underwater. This paper explores underwater operation potential of an emerging solid-state technology: friction stir deposition, wherein feeding bonding are enabled by mechanical forces with minimal influences from water. It is demonstrated that deposition 304 stainless steel can be successfully performed print head substrate immersed High...
Additive friction stir deposition (AFSD) is a solid-state metal additive manufacturing technique, which utilizes frictional heating and plastic deformation to create large deposits parts. Much like its cousin processes, welding processing, AFSD has seen the most compatibility use with lower-temperature metals, such as aluminum; however, there growing interest in higher-temperature materials, titanium steel alloys. In this work, we explore of an ultrahigh-temperature refractory material,...
Understanding plutonium’s interaction with metals is crucial for optimizing pyrochemical operations, nuclear fuel containment, and various actinide processing techniques. Traditionally, tantalum crucibles are employed plutonium due to their high durability, excellent temperature stability, low solubility in plutonium. However, faces challenges such as wetting diffusion, making surface coatings particularly important applications enhance corrosion resistance against Tantalum also expensive...
Within the Lorne Basin, Mesozoic granitoid plutons and dacitic to rhyolitic extrusions form extensive components in a faulted, eroded Triassic sedimentary basin. Late Cenozoic plugs flows of evolved basalts represent easterly extensions Comboyne Volcano. The basin marks terminal outpost New England Orogen, much modified by later alkaline felsic intrusions flow remnants. Many origins are invoked for its tectonic genesis magmatic evolution including plate tectonic, caldera even meteoritic...
It is now widely accepted that, in many cases, the democratization process that began Africa 1990 has been crippled by several factors (Chazan 1994; Bratton Lemarchand 1992). These range from weak patterns of state-society relations to economic disequilibium. Another potential obstacle received little examination trend, particularly West Africa, military rulers resigning their commissions and competing “democratic” elections designed supervised regimes (The New York Times, 24 October, 1996)....
Abstract Additive friction stir deposition is an emerging solid-state additive manufacturing technology that has shown promise for bulk fabrication of metals and metal-matrix composites. Here, we perform a preliminary investigation into the influence tool geometries on particle distribution matrix-particle coherence SiC in matrix Aluminum Alloy 6061 commercially pure Copper. Two have been used: (1) simple, featureless (2) complex geometry with four surface protrusions. For simple geometry,...