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At least 19 records

Disassembling 2D van der Waals crystals into macroscopic monolayers and reassembling into artificial lattices

Two-dimensional materials from layered van der Waals (vdW) crystals hold great promise for electronic, optoelectronic, and quantum devices, but technological implementation will be hampered by the lack of high-throughput techniques for exfoliating single-crystal monolayers with sufficient size and high quality. Here, we report a facile method to disassemble vdW single crystals layer by layer into monolayers with near-unity yield and with dimensions limited only by bulk crystal sizes. The macroscopic monolayers are comparable in quality to microscopic monolayers from conventional Scotch tape exfoliation. The monolayers can be assembled into macroscopic artificial structures, including transition metal dichalcogenide multilayers with broken inversion symmetry and substantially enhanced nonlinear optical response. This approach takes us one step closer to mass production of macroscopic monolayers and bulk-like artificial materials with controllable properties.

Science & Technology - Other Topics↗

Reimagining Disassembly Interfaces With Visualization: Combining Instruction Tracing and Control Flow With DisViz

In applications where efficiency is critical, developers may examine their compiled binaries, seeking to understand how the compiler transformed their source code and what performance implications that transformation may have. This analysis is challenging due to the vast number of disassembled binary instructions and the many-to-many mappings between them and the source code. These problems are exacerbated as source code size increases, giving the compiler more freedom to map and disperse binary instructions across the disassembly space. Interfaces for disassembly typically display instructions as an unstructured listing or sacrifice the order of execution. Here, we design a new visual interface for disassembly code that combines execution order with control flow structure, enabling analysts to both trace through code and identify familiar aspects of the computation. Central to our approach is a novel layout of instructions grouped into basic blocks that displays a looping structure in an intuitive way. We add to this disassembly representation a unique block-based mini-map that leverages our layout and shows context across thousands of disassembly instructions. Finally, we embed our disassembly visualization in a web-based tool, DisViz, which adds dynamic linking with source code across the entire application. DizViz was developed in collaboration with program analysis experts following design study methodology and was validated through evaluation sessions with ten participants from four institutions. Participants successfully completed the evaluation tasks, hypothesized about compiler optimizations, and noted the utility of our new disassembly view. Our evaluation suggests that our new integrated view helps application developers in understanding and navigating disassembly code.

Computer science↗

AGC-4 Disassembly Report

The Advanced Reactor Terminology Graphite Research and Development program is currently measuring irradiated material property changes in several grades of nuclear graphite to predict behavior and operating performance within the core of these new high temperature reactor designs. The Advanced Graphite Creep (AGC) experiment, consisting of six irradiation capsules, will generate the irradiated graphite performance data for the Very High Temperature Reactor operating conditions. All six capsules in the experiment conducted at Idaho National Laboratory will be irradiated in the Advanced Test Reactor, disassembled in the Hot Fuel Examination Facility, and examined at the Idaho National Laboratory Research Center. This is the disassembly report describing the disassembly, shipment, post irradiation inspection, and storage of the graphite specimens contained within the AGC 4 irradiation test series capsule (the fourth irradiation capsule of the series). AGC 4 was irradiated in the Advanced Test Reactor (ATR) East Flux Trap (EFT) during ATR Cycle 157D, 158A, 162A, 162B, 164A, 164B, 166A, and Cycle 166B. Approximately 3.6 dpa was achieved. Desired experiment temperatures were exceeded by at least 100C during the second Cycle of irradiation due to the insertion of the KJRR experiment. The capsule was removed from the ATR and transferred to the Hot Fuel Examination Facility on May 15, 2020 and eventually unloaded into the Hot Fuel Examination Facility (HFEF) Decon Cell through Penetration 2D on February 26, 2021. It was moved to the HFEF Main Cell Window 3M for disassembly on March 15, 2021. Disassembly and specimen extraction began March 18, 2021, and packaging of the graphite specimens was completed on April 16, 2021. Several anomalies were noted, specifically that the radiological dose rates were nominally an order of magnitude higher than that of the previous AGC experiments. This report summarizes the disassembly of the AGC 4 experiment.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

AGC-4 Disassembly Report

The Advanced Reactor Terminology Graphite Research and Development program is currently measuring irradiated material property changes in several grades of nuclear graphite to predict behavior and operating performance within the core of these new high temperature reactor designs. The Advanced Graphite Creep (AGC) experiment, consisting of six irradiation capsules, will generate the irradiated graphite performance data for the Very High Temperature Reactor operating conditions. All six capsules in the experiment conducted at Idaho National Laboratory will be irradiated in the Advanced Test Reactor, disassembled in the Hot Fuel Examination Facility, and examined at the Idaho National Laboratory Research Center. This is the disassembly report describing the disassembly, shipment, post irradiation inspection, and storage of the graphite specimens contained within the AGC 4 irradiation test series capsule (the fourth irradiation capsule of the series). AGC 4 was irradiated in the Advanced Test Reactor (ATR) East Flux Trap (EFT) during ATR Cycle 157D, 158A, 162A, 162B, 164A, 164B, 166A, and Cycle 166B. Approximately 3.6 dpa was achieved. Desired experiment temperatures were exceeded by at least 100C during the second Cycle of irradiation due to the insertion of the KJRR experiment. The capsule was removed from the ATR and transferred to the Hot Fuel Examination Facility on May 15, 2020 and eventually unloaded into the Hot Fuel Examination Facility (HFEF) Decon Cell through Penetration 2D on February 26, 2021. It was moved to the HFEF Main Cell Window 3M for disassembly on March 15, 2021. Disassembly and specimen extraction began March 18, 2021, and packaging of the graphite specimens was completed on April 16, 2021. Several anomalies were noted, specifically that the radiological dose rates were nominally an order of magnitude higher than that of the previous AGC experiments. This report summarizes the disassembly of the AGC 4 experiment.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

How short peptides disassemble tau fibrils in Alzheimer’s disease

Reducing fibrous aggregates of the protein tau is a possible strategy for halting the progression of Alzheimer’s disease (AD). Previously, we found that in vitro, the d-enantiomeric peptide (D-peptide) D-TLKIVWC disassembles ultra-stable tau fibrils extracted from the autopsied brains of individuals with AD (hereafter, these tau fibrils are referred to as AD-tau) into benign segments, with no energy source other than ambient thermal agitation. To consider D-peptide-mediated disassembly as a potential route to therapeutics for AD, it is essential to understand the mechanism and energy source of the disassembly action. Here, in this work, we show that the assembly of D-peptides into amyloid-like (‘mock-amyloid’) fibrils is essential for AD-tau disassembly. These mock-amyloid fibrils have a right-handed twist but are constrained to adopt a left-handed twist when templated in complex with AD-tau. The release of strain that accompanies the conversion of left-twisted to right-twisted, relaxed mock-amyloid produces a torque that is sufficient to break the local hydrogen bonding between tau molecules, and leads to the fragmentation of AD-tau. This strain-relief mechanism seems to operate in other examples of amyloid fibril disassembly, and could inform the development of first-in-class therapeutics for amyloid diseases.

Alzheimer's disease↗

Automation for Electric Vehicle Battery Pack Disassembly

Battery‐electric vehicles (EVs) are growing exponentially. The demand for these batteries is expected to increase sevenfold by 2035. The EV batteries reach their end of life when the capacity fades to 70%–80% of new, with some being removed from the primary applications with even lower levels of degradation. These batteries can be used in less demanding applications. The disassembly process is currently manual, slow, unsafe, and expensive. Automation is needed to increase the throughput. EV battery packs feature various continually changing designs and form factors, which limit the usefulness of deterministically programmed robotic solutions. The conceptual robotic disassembly of EV batteries has attracted the attention of researchers. However, while many approaches have been proposed, practical implementations are lacking. Here, we review proposed concepts for EV battery disassembly and describe the selected approach, with elements of partial solutions validated in a laboratory setting, including the selection of commercial solutions, the development of custom end effectors, and methodologies for detection, localization, and classification of fasteners. The computer vision tasks employed an overhead 2D camera to detect the type of battery pack and approximate localization of fasteners, and a 3D camera mounted on the robotic arm for precise localization (position and tilt) and classification.

Islam, Abu [Rochester Inst. of Technology, Rochest↗

Photographic Mitigation Documentation Related to the Engine Assembly and Disassembly Facility, Area 25, Nevada National Security Site, Nye County, Nevada

This letter report provides documentation in partial fulfillment of the mitigation of adverse effects to the Engine Maintenance Assembly and Disassembly (E-MAD) facility, a major component of the Nuclear Rocket Development Station (NRDS) Historic District located in Area 25 of the Nevada National Security Site (NNSS). Construction of the E-MAD facility began in 1962 for the purpose of disassembling and maintaining nuclear-powered rocket engines. Once the building was complete in 1967, the E-MAD facility remained in continuous operation until the nuclear rocket program was terminated in 1973. The mothballed facility was repurposed in 1977 for spent nuclear fuel handling and packaging activities. By the mid-1980s, all activities at the E-MAD facility had ceased (Reno et al. 2019). This submission is intended to comply with Stipulation III.D.1 of the Memorandum of Agreement DE-GM58-20NA25534 between the U.S. Department of Energy and the Nevada State Historic Preservation Officer Regarding Corrective Action Activities and Demolition of the Engine Maintenance Assembly and Disassembly Facility and the Test Cell C Historic District, Major Components of the Nuclear Rocket Development Station Historic District Located in Area 25 at the Nevada National Security Site Nye County (hereafter referred to as the MOA). Stipulation III.D.1 states the U.S. Department of Energy (DOE) will submit the existing supplementary collection of the large-format, black-and-white photographic prints taken during the 1996 Historic American Engineering Record (HAER) documentation of the E-MAD facility to the Nuclear Testing Archive (NTA), located on the second floor of the Rogers Building at Desert Research Institute (DRI) in Las Vegas, Nevada.

54 ENVIRONMENTAL SCIENCES↗

Alignment Pins for Assembling and Disassembling Structures

Simple, easy-to-use, highly effective tooling has been devised for maintaining alignment of bolt holes in mating structures during assembly and disassembly of the structures. The tooling was originally used during removal of a body flap from the space shuttle Atlantis, in which misalignments during removal of the last few bolts could cause the bolts to bind in their holes. By suitably modifying the dimensions of the tooling components, the basic design of the tooling can readily be adapted to other structures that must be maintained in alignment. The tooling includes tapered, internally threaded alignment pins designed to fit in the bolt holes in one of the mating structures, plus a draw bolt and a cup that are used to install or remove each alignment pin. In preparation for disassembly of two mating structures, external supports are provided to prevent unintended movement of the structures. During disassembly of the structures, as each bolt that joins the structures is removed, an alignment pin is installed in its place. Once all the bolts have been removed and replaced with pins, the pins maintain alignment as the structures are gently pushed or pulled apart on the supports. In assembling the two structures, one reverses the procedure described above: pins are installed in the bolt holes, the structures are pulled or pushed together on the supports, then the pins are removed and replaced with bolts. The figure depicts the tooling and its use. To install an alignment pin in a bolt hole in a structural panel, the tapered end of the pin is inserted from one side of the panel, the cup is placed over the pin on the opposite side of the panel, the draw bolt is inserted through the cup and threaded into the pin, the draw bolt is tightened to pull the pin until the pin is seated firmly in the hole, then the draw bolt and cup are removed, leaving the pin in place. To remove an alignment pin, the cup is placed over the pin on the first-mentioned side of the panel, the draw bolt is inserted through the cup and threaded into the pin, then the draw bolt is tightened to pull the pin out of the hole.

Campbell, Oliver C.↗

Joining, Disassembly, and Reconfiguration of Thermoplastic Composites for Space Applications

Thermoplastic composites are increasingly being investigated for aerospace applications because of their relatively short processing time, good chemical and radiation resistance, and potential for reforming and reuse via melting. The manufacturing, reforming, and reuse of thermoplastic composites can be leveraged to advance joining, disassembly, and reassembly of structures for space exploration activities. Potential applications include, but are not limited to, habitats and on-orbit assembly and reassembly of large-scale truss structures. This work focuses on demonstrating the feasibility of joining, disassembly, and reassembly of a thermoplastic bond using heat and pressure. Polyether ether ketone (PEEK) composite adherends were joined using low-melt polyaryl ether ketone (LM-PAEK) thermoplastic films at the bonding interface. The single lap shear specimens with LM-PAEK film were tested and had a maximum shear strength between 5 and 8 MPa and consistently failed adhesively at the bondline. Reassembly of disassembled specimens was successfully demonstrated using additional thermoplastic interlayers. Thus, the reassembly of thermoplastic composite joints was found to be feasible. However, additional work is required to reduce film flowout and optimize consolidation parameters for an in space environment.

thermoplastic composites↗

Assignment of structural transitions during mechanical unwrapping of nucleosomes and their disassembly products

Nucleosome DNA unwrapping and its disassembly into hexasomes and tetrasomes is necessary for genomic access and plays an important role in transcription regulation. Previous single-molecule mechanical nucleosome unwrapping revealed a low- and a high-force transitions, and force-FRET pulling experiments showed that DNA unwrapping is asymmetric, occurring always first from one side before the other. However, the assignment of DNA segments involved in these transitions remains controversial. Here, using high-resolution optical tweezers with simultaneous single-molecule FRET detection, we show that the low-force transition corresponds to the undoing of the outer wrap of one side of the nucleosome (∼27 bp), a process that can occur either cooperatively or noncooperatively, whereas the high-force transition corresponds to the simultaneous unwrapping of ∼76 bp from both sides. This process may give rise stochastically to the disassembly of nucleosomes into hexasomes and tetrasomes whose unwrapping/rewrapping trajectories we establish. In contrast, nucleosome rewrapping does not exhibit asymmetry. To rationalize all previous nucleosome unwrapping experiments, it is necessary to invoke that mechanical unwrapping involves two nucleosome reorientations: one that contributes to the change in extension at the low-force transition and another that coincides but does not contribute to the high-force transition.

59 BASIC BIOLOGICAL SCIENCES↗

AGR 5/6/7 Disassembly and Metrology

AGR 5/6/7 Disassembly and Metrology background, disassembly obervations on graphite holders and fuel compacts, metrology fuel compacts and graphite holders, and summary.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Disassembly of Capsules after Irradiation of Prototype Metal and Nanocomposite Specimens in the High Flux Isotope Reactor

This report summarizes the disassembly, thermometry (TM) analysis, and future post-irradiation examination of irradiation capsules that contain nanodispersion-strengthened materials for the improved neutron irradiation resistance of fuel cladding and reactor core materials. All six capsules were successfully disassembled, and all TM was shipped to the Low Activation Materials Development and Analysis Laboratory for further analysis. The results of this project will support the development of new radiation-resistant materials by helping researchers understand the mechanism of defect evolution at interfaces in nanodispersion-strengthened materials.

36 MATERIALS SCIENCE↗

Unwrapping Radiograph Target Disassembly Using Adaptive Machine Learning [Slides]

Advanced analysis methods were developed to determine the electron temperature and density evolution of targets disassembly by intense electron beams at DARHT based on shearing interferometer and shadowgraph measurements. New methods have been developed to spatially and temporally resolve electron velocity and temperature, expanding on recently published first results of Aluminum target disassembly. A surrogate model has been created for use in developing Adaptive Machine Learning analysis techniques. The results will also be used to guide the development of the system and experimental approach to future measurements on DARHT Axis-I and a new system to be deployed on DARHT Axis-II.

43 PARTICLE ACCELERATORS↗

Standard operating procedure for post-operation component disassembly and observation of benchtop water electrolyzer testing

Post-operation component disassembly and observation of electrolyzer parts is useful in understanding the interactions of the components and the electrochemical environment beyond the systems electrochemical output. We report a standard protocol for post-operation component disassembly and observation, including directions for cell-component preservation, preliminary visual inspection of cell components, and a guide for the advanced inspection of specific components with suggestions for further analysis if necessary. The procedures outlined here allow for a standardized method that can be used and compared between different laboratories and for literature comparison to experimental results.

03 NATURAL GAS↗

Recycling Disassembled Automotive Plastic Components for New Vehicle Components: Enabling the Automotive Circular Economy

As the automotive industry increasingly relies on plastic components to meet fuel efficiency and emissions targets, the challenge of managing end-of-life vehicle (ELV) plastics continues to grow. Currently, more than 80% of ELV plastics in the U.S. are landfilled due to limited economic incentives and technical barriers to recycling. This study examines a mechanical recycling pathway for thermoplastic components disassembled from ELVs and assesses their usability for reintegration into new vehicle parts. Four representative materials were chosen based on material labels embedded in recovered parts and aligned with their virgin industrial equivalents: polypropylene (PP), 10% talc-filled PP (PP-T10), 20% talc-filled PP (PP-T20), and a 20% glass-/mineral-filled polyamide (PA6 + GF7 + MF13). The materials underwent shredding, drying, and injection molding before being characterized by particle size analysis, density measurement, thermal analysis (TGA, DSC), mechanical testing, and heat deflection temperature (HDT) evaluation. The results in this work indicated that minor differences in crystallinity were observed and small differences between model materials and ELV materials could have contributed to these changes. Mechanical testing revealed that neat polypropylene suffered a 15–20% reduction in stiffness and tensile strength, but talc-filled polypropylene and glass/mineral-filled nylon retained >90% of their modulus, strength, and heat deflection temperature values relative to virgin controls. Differences between virgin and ELV materials could have been attributed to use life degradation, contamination during use life, or even chemical/processing differences in model materials and ELV materials. However, these findings suggest that mechanically recycled, disassembled ELV plastics can retain sufficient structural performance to support circularity efforts in the automotive sector.

automotive recycling↗

Damage-Free Relief-Valve Disassembly

Tool safely disassembles relief valves without damage to sensitive parts. Relief-valve disassembly tool used to extract valve nozzle from its housing. Holding device on tool grops nozzle. When user strikes hammer against impact disk, holding device pulls nozzle from press fit. Previously, nozzle dislodged by striking spindle above it, but practice often damaged retaining screw. New tool removes nozzle directly. With minor modifications, tool adapted to valves from different manufacturers.

Haselmaier, H.↗

Assembly, disassembly and repair of large truss structures in space

This paper addresses the problem of planning assembly, disassembly and repair sequences for large truss structures in space. First, the AND/OR graph representation scheme for mechanical assemblies is reviewed and extended to truss structures. The assembly, disassembly and repair sequence planning problem is then formulated as a graph search problem using assembly's AND/OR graph and appropriate cost functions. The general search problem, which is known to be exponential, is simplified by taking advantage of the symmetries that exist in truss structures. General cost functions for truss assembly are discussed.

Desai, Rajiv S.↗

Strategies for achieving circular economy goals in the lighting industry through design for disassembly- based methodologies

The significance of circular economy and its integration into core strategies for smart, sustainable, and inclusive growth, is increasingly being recognized by individuals, organisations, and nations in recent times. The term Design for Disassembly (DfD) may conjure up images about the end-of-life of a product or its disposal. However, DfD connects to numerous circularity and sustainability goals over the lifetime of a product or project and can have a large impact on the carbon footprint of the product. The DfD is a product development methodology which is in line with the vision of a circular economy, and supports increase in material efficiency, extends product lifetimes and improves recycling efficiency. Reduction of the imposed environmental risks and impact on the climate, by utilising circularity approaches such as remanufacturing, are tied to lowering of carbon footprint. This paper describes specific and actionable approaches that can be applied by luminaire manufacturers, specifiers, and other players in the lighting industry. The readers will learn about current tools and methodologies that can be used to improve iterative design, as well as measure, assess, and compare products or materials.

design for disassembly, dfd, circularity↗