A Novel Parameter for Fatigue Damage Assessment of Laser-Repaired Nickel-Based Alloy.

The fatigue damage assessment of laser-repaired components is critical to their service safety. However, since laser repairing is an advanced green remanufacturing technology, the current research on its fatigue mechanical behavior and fatigue damage evaluation methods is still immature. In addition, the relevant models used for the fatigue damage evaluation can only indicate the fatigue limit of components, which cannot describe the damage accumulation process of the components during the fatigue testing.

IntelliScan: Improving the quality of x-ray computed tomography surface data through intelligent selection of projection angles.

X-ray computed tomography (XCT) enables the dimensional measurement and inspection of highly geometrically complex engineering components that are unmeasurable using optical and tactile instruments. Conventional XCT scans use a circular scan trajectory where X-ray projections are acquired with a uniform angular spacing; this approach treats all projections as being of equal importance, in practice, some projections contain more object information than others. In this work we capitalize on this concept by intelligently selecting projections with a view to improve the quality of surface models extracted from an XCT data-set.

Gradient Structure Design and Welding-Hammering Hybrid Remanufacturing Process of Continuous Casting Rollers.

To improve the service life and reduce the repair cost of continuous casting rollers, a new welding-hammering hybrid remanufacturing process in which the roller was designed with a gradient structure was proposed, and corresponding equipment was developed. First, the failure modes and their causes for a continuous casting roller were analyzed by numerical simulation. The cyclic tension-compression shear stress, cyclic tension-compression normal stress, thermal cycle, and highly corrosive environment caused fatigue cracking and overall peeling of the roller surface.

A new approach to simultaneously reducing, nitrogen doping and noble metal coating of graphene oxide via active-screen plasma.

Graphene is widely used for various applications, especially after nitrogen doping and incorporation with metal nanoparticles. Herein, a simultaneous approach to reducing, nitrogen doping and noble metals coating of graphene oxide (GO) is reported using an advanced active-screen plasma (ASP) technique. With a noble metal plate added as an extra lid of active screen cage, the corresponding noble metal, mainly or fully in pure metal state, depending on the noble metal type, as well as a minority of Fe and Cr, is deposited on GO with simultaneous reduction and nitrogen doping.

Supply chain optimisation for recycling and remanufacturing sustainable management in end-of-life vehicles: A mini-review and classification.

End-of-life vehicles (ELV) management is becoming a global concern in the automotive industry. However, there is still limited study on supply chain optimisation that focusses on specific ELV treatments. Therefore, this mini-review article analyses the supply chain optimisation for recycling and remanufacturing sustainable management in ELV.

Upcycling Glass Waste into Porous Microspheres for Wastewater Treatment Applications: Efficacy of Dye Removal.

Each year about 7.6 million tons of waste glasses are landfilled without recycling, reclaiming or upcycling. Herein we have developed a solvent free upcycling method for recycled glass waste (RG) by remanufacturing it into porous recycled glass microspheres (PRGMs) with a view to explore removal of organic pollutants such as organic dyes.

Developing high intensity ultrasonic cleaning (HIUC) for post-processing additively manufactured metal components.

The high energy phenomenon of cavitation bubble collapses has enabled numerous applications, including cleaning. In ultrasonic cleaning, cavitation intensity is typically lower than in other applications, such as sonochemistry and material processing. However, there has been an emerging application in intense cleaning of metal additively manufactured (AM) components.

3D ultrasonic imaging of surface-breaking cracks using a linear array.

Ultrasonic linear arrays have great potential to generate high-quality three-dimensional (3D) images by scanning the array. However, the generated images suffer from low resolution in the elevation plane, limiting the image quality for a reliable 3D Non-Destructive Testing (NDT) inspection. Although several ultrasonic imaging methods have been implemented to inspect different types of defects, there has been limited research to characterise surface-breaking cracks (SBCs) in 3D quantitatively.

Stress Evaluation of Welded Joints with Metal Magnetic Memory Testing Based on Tension-Compression Fatigue Test.

Metal magnetic memory testing (MMMT) is an effective nondestructive technique for fatigue damage monitoring of weldments because of its capacity for stress evaluation. An experimental investigation of the effect of the applied fatigue stress on MMMT signals, including the tangential component and the normal component , during tension-compression fatigue tests in welded joints was carried out systematically. The and signals at different fatigue cycles and fatigue stresses were collected and analyzed, and the results showed that there was a peak of and abnormal peaks of that existed at the welded joint before loading.

Modeling and Analyzing the Impact of the Internet of Things-Based Industry 4.0 on Circular Economy Practices for Sustainable Development: Evidence From the Food Processing Industry of China.

The Industry 4.0 concept proposes that new cutting-edge technologies, such as the Internet of Things (IoT), will grow. The acceptance of IoT in the circular economy (CE) is still in its infancy, despite its enormous potential.

Research on services decision-making in closed-loop supply chain dominated by a logistics provider.

Remanufacturing is an advanced form of recycling in circular economy. In order to promote the development of remanufacturing, the government gradually uses subsidy policies to regulate and intervene related enterprises. In this paper, we assume that a closed-loop supply chain consists of an original equipment manufacturer (OEM) producing new products from raw materials, a remanufacturer producing re-manufactured products from used items directly collected from customers, and a logistics provider which sells and distributes two products as a monopolist in the given market.

Through transmission ultrasonic inspection of fiber waviness for thickness-tapered composites using ultrasound non-reciprocity: Simulation and experiment.

This study proposed the use of ultrasound non-reciprocity in periodic structures to inspect fiber waviness in thickness-tapered composites. Ultrasound propagation in plain and thickness-tapered composites with complex microstructure were precisely modelled using TexGen® and OnScale® simulation software. Ultrasound non-reciprocity and attenuation was comparatively calculated to inspect fiber waviness through both simulation and experiment.

Environmental benefits of remanufacturing mechanical products: a harmonized meta-analysis of comparative life cycle assessment studies.

Remanufactured mechanical products with high-added value are generally claimed to gain environmental benefits. These claims were made based on different products and assessment methodologies. The variability of life cycle assessment (LCA) results precludes a meaningful comparison across products and studies.

Intelligent systems for additive manufacturing-based repair in remanufacturing: a systematic review of its potential.

The conventional component repair in remanufacturing involves human decision making that is influenced by several factors such as conditions of incoming cores, modes of failure, severity of damage, features and geometric complexities of cores and types of reparation required. Repair can be enhanced through automation using additive manufacturing (AM) technology. Advancements in AM have led to the development of directed energy deposition and laser cladding technology for repair of damaged parts and components.

A Transferrable, Adaptable, Free-Standing, and Water-Resistant Hyperbolic Metamaterial.

Hyperbolic metamaterials (HMMs) have attracted significant attention due to the profound manipulation of the photonic density of states, resulting in the efficient optoelectronic devices with the enhanced light-matter interaction. HMMs are conventionally built on rigid large-size substrates with poor conformability and the absence of flexibility. Here, we demonstrate a grating collageable HMM (GCHMM), which is composed of eight alternating layers of Au and poly(methyl methacrylate) (PMMA) and PMMA grating nanostructure containing quantum dots (QDs).

Phase Transition Effect on Ferroelectric Domain Surface Charge Dynamics in BaTiO Single Crystal.

The ferroelectric domain surface charge dynamics after a cubic-to-tetragonal phase transition on the BaTiO single crystal (001) surface was directly measured through scanning probe microscopy. The captured surface potential distribution shows significant changes: the domain structures formed rapidly, but the surface potential on polarized domain was unstable and reversed its sign after lengthy lapse; the high broad potential barrier burst at the corrugated domain wall and continued to dissipate thereafter. The generation of polarization charges and the migration of surface screening charges in the surrounding environment take the main responsibility in the experiment.

Exploring Contact Angle Hysteresis Behavior of Droplets on the Surface Microstructure.

It is confirmed that surfaces with specific microstructures could exhibit good superhydrophobic properties, and there are also a lot of conclusions about droplet hysteresis behavior. However, most of the research methods are based on two-dimensional ideal model and experimental observation at the macroscale. Further research needs to be conducted about the hysteresis behavior of droplets on the microstructure surface under three-dimensional conditions.

Estimating the Product of the X-ray Spectrum and Quantum Detection Efficiency of a CT System and Its Application to Beam Hardening Correction.

Lab-based X-ray computed tomography (XCT) systems use X-ray sources that emit a polychromatic X-ray spectrum and detectors that do not detect all X-ray photons with the same efficiency. A consequence of using a polychromatic X-ray source is that beam hardening artefacts may be present in the reconstructed data, and the presence of such artefacts can degrade XCT image quality and affect quantitative analysis. If the product of the X-ray spectrum and the quantum detection efficiency (QDE) of the detector are known, alongside the material of the scanned object, then beam hardening artefacts can be corrected algorithmically.

Leveling the cost and carbon footprint of circular polymers that are chemically recycled to monomer.

Mechanical recycling of polymers downgrades them such that they are unusable after a few cycles. Alternatively, chemical recycling to monomer offers a means to recover the embodied chemical feedstocks for remanufacturing. However, only a limited number of commodity polymers may be chemically recycled, and the processes remain resource intensive.

Micropatterning of polymer substrates for cell culture.

The cell microenvironment such as substrate topology plays an important role in biological processes. In this study, microgrooves were successfully produced on surfaces of both thermoplastic and thermoset polymers using cost-effective techniques for mass production. The micropatterning of thermoplastic polystyrene (PS) petri dish was accomplished efficiently using an in-house developed low-cost hot embossing system.

Numerical Simulation and Experimental Study on Residual Stress in the Curved Surface Forming of 12CrNi2 Alloy Steel by Laser Melting Deposition.

The performance and service life of the nuclear emergency diesel engine shaft made of 12CrNi2 alloy steel is very important for the safety of nuclear power. Laser melting deposition (LMD) is a challenging camshaft-forming technology due to its high precision, rapid prototyping, and excellent parts performance. However, LMD is an unsteady process under the local action of laser, especially for curved surface forming, which is more likely to generate large residual stress on components, resulting in cracks and other defects.

Interfacial viscoelasticity and jamming of colloidal particles at fluid-fluid interfaces: a review.

Colloidal particles can be adsorbed at fluid-fluid interfaces, a phenomenon frequently observed in particle-stabilized foams, Pickering emulsions, and bijels. Particles adsorbed at interfaces exhibit unique physical and chemical behaviors, which affect the mechanical properties of the interface. Therefore, interfacial colloidal particles are of interest in terms of both fundamental and applied research.

On-Substrate Joule Effect Heating by Printed Micro-Heater for the Preparation of ZnO Semiconductor Thin Film.

Fabrication of printed electronic devices along with other parts such as supporting structures is a major problem in modern additive fabrication. Solution-based inkjet printing of metal oxide semiconductor usually requires a heat treatment step to facilitate the formation of target material. The employment of external furnace introduces additional complexity in the fabrication scheme, which is supposed to be simplified by the additive manufacturing process.

Spatial resolution improvement of 450 kV computed tomography via vertical subpixel detector shifting.

X-ray sources with acceleration voltages of 450 kV typically have large focal spot sizes that lead to low spatial resolution computed tomography (CT) data. In this work a method to improve the spatial resolution of 450 kV CT is developed. The proposed method relies on using vertical subpixel detector shifting and deconvolution to generate a projection-set that has double the number of pixels in the direction parallel to the axis of rotation.

Influence of Crack Size on Stress Evaluation of Ferromagnetic Low Alloy Steel with Metal Magnetic Memory Technology.

Based on the magneto-mechanical effect, the influence of crack size on stress evaluated with metal magnetic memory (MMM) technology was discussed in this paper. Based on equivalent theory, the regular rectangular grooves, with different widths and depths, were precut in the surface of an experimental sample for simulating surface crack, and a three dimensional electrically controlled displacement system was used to collect the () signal of the sample under different stresses, and the fracture morphology was observed by using scanning electron microscopy (SEM). The results show that the influence of detection line on () signal can be ignored; as stress increases, the () signal turns counterclockwise around zero-crossing point and its mutation, corresponding to the location of groove, becomes distinct gradually.