Filament Diameter Research Articles

Did the first two Argentine flags of Macha and Ayohuma wave together?

Historical sources claim that the Argentine ensigns commonly referred to as Macha and Ayohuma flags have the same origin. The difference in their designs is remarkable, with the former being white, blue, and white in horizontal bands, while the latter has the coloured stripes at its ends. According to a historical account, these two flags were used by the patriot and creator of the Argentine flag, one of the parents of the homeland, Manuel Belgrano, when he first raised them on the banks of the Paraná River on February 27, 1812. Both flags were found by Father Martín Castro in 1883 behind a painting of Santa Cecilia in the church of Titiri near the town of Macha in Bolivia at an altitude of 4350 m above sea level. The composition of the Ayohuma flag was analysed in this paper, and the results were compared with those obtained and already published for the study conducted on the flag of Macha. It was determined by ATR-FTIR spectroscopy that the Ayohuma flag is made of silk, with the diameter of the individual silk filament of 12.5 μm, the dye used to colour the silk is indigotin, according to its resonance Raman spectrum, and methylene blue was detected by Surface-Enhanced Resonance Raman Spectroscopy, presumably utilized for the restoration of the coloured part of the flag.

Impact of local plastic deformation on thermo-magnetic instability of high-J c Nb3Sn strand

The future fusion reactor devices built by Institute of Plasma Physics, Chinese Academy of Science will be a compact burning plasma facility to fill the gap between ITER and the China Fusion Engineering Test Reactor, with the mission of studying the deuterium–tritium plasma in steady-state operation. The winding-package (WP) of its toroidal field coil is graded into high-field WP and low-field WP, and the high critical current density (J c) Nb3Sn strand will be applied to the high-field WP based on the current design. The thermo-magnetic instability is the main issue in the application of high-J c Nb3Sn strand, which may induce premature quenching in the low field regions. This issue can be improved by reducing the effective filament diameter (d eff) to suppress flux jumps and increasing the residual resistivity ratio (RRR) to enhance the release of heat generated by flux jumps. However, in the conductor manufacturing process, local plastic deformations (indentation) of strands can impact the sub-element layout and degrade the RRR of the strand, which would increase again the risk on instability. In this study, magnetization measurements and V–I tests were performed on samples with different indentation depths. The hysteresis loss and d eff of the indented sample was obtained from the test results. The impact of local plastic deformation on the thermo-magnetic instability of two types of Nb3Sn strand was confirmed by cross-sectional metallographic observation and quantitative microstructure analysis. It was shown that flux jumps were suppressed at indentation depths below 0.3 mm. Further indentation increase leads to severe flux jumps.

Layer thickness and path width setting in 3D printing of pre-impregnated continuous carbon, glass fibers and their hybrid composites

3D printing has been successfully applied in the manufacturing of variety continuous fiber and hybrid fiber reinforced composites. The process parameters have a significant impact on the overall performance of the printed parts. This paper investigates the effects of layer thickness and path width on the bending strength and surface roughness of printed pre-impregnated continuous carbon fiber, glass fiber, and their hybrid composites. Additionally, the microstructures of the fracture surfaces of the printed parts were analyzed. The results indicate that the optimal combination of bending strength and surface accuracy for printed single fiber parts is achieved when the printing layer thickness is set to 30%–40% of the fiber filament diameters. Furthermore, finely matched path width settings significantly improve the surface accuracy of printed hybrid carbon/glass fiber composites. Notably, the bending strength of printed interlayer hybrid fiber composite specimens increased by 35% compared to the specimens uniformly set according to the carbon fiber path width.

Solvent-cast 3D printing with molecular weight polymer blends to decouple effects of scaffold architecture and mechanical properties on mesenchymal stromal cell fate.

The biochemical and physical properties of a scaffold can be tailored to elicit specific cellular responses. However, it is challenging to decouple their individual effects on cell-material interactions. Here, we solvent-cast 3D printed different ratios of high and low molecular weight (MW) poly(caprolactone) (PCL) to fabricate scaffolds with significantly different stiffnesses without affecting other properties. Ink viscosity was used to match processing conditions between inks and generate scaffolds with the same surface chemistry, crystallinity, filament diameter, and architecture. Increasing the ratio of low MW PCL resulted in a significant decrease in modulus. Scaffold modulus did not affect human mesenchymal stromal cell (hMSC) differentiation under osteogenic conditions. However, hMSC response was significantly affected by scaffold stiffness in chondrogenic media. Low stiffness promoted more stable chondrogenesis whereas high stiffness drove hMSC progression toward hypertrophy. These data illustrate how this versatile platform can be used to independently modify biochemical and physical cues in a single scaffold to synergistically enhance desired cellular response.

Formation of layered nanofibric materials and composite coatings

Using an electrospinning device, we determined the optimal conditions for producing nanofibers from a 10% solution of Co–AN. These conditions involved applying a 15[Formula: see text]kV voltage to the anode, which was connected to the syringe containing the solution, and maintaining a distance of 12–15[Formula: see text]cm from the needle tip to the collector screen (cathode). The filament diameter (d) ranged from 0.2 to 0.5[Formula: see text]mm. This setup allowed the formation of nanofibers under the cover. The electrolysis process was conducted for varying durations, ranging from 4 to 14[Formula: see text]h, while applying currents of 2[Formula: see text]mA, 4[Formula: see text]mA, and 8[Formula: see text]mA. At 4[Formula: see text]mA and 8[Formula: see text]mA, a substantial portion (approximately 65–70%) of the macroions in the solution reassembled on the electrode surfaces. These images clearly illustrate the restoration of macroions on the electrode surfaces, achieved through electron exchange processes. This phenomenon results in the combination of macroions and their neutralization, leading to the formation of a composite coating on the titanium, iron plate, and rods.

Macromolecular structure development of dry-spinning UHMWPE fibers through the industrial high-ratio hot-drawing process

Ultra-high molecular weight polyethylene (UHMWPE) and its decalin suspension were subjected to several industrial processes including swelling, dissolving, spinning, drying, and multi-stage high-ratio hot drawing to fabricate UHMWPE fibers (UPE fibers). The morphologies and architectures of the UPE fibers at different drawing stages were characterized by polarizing optical microscope (POM), scanning electron microscope (SEM) and atomic force microscopy (AFM). The aggregation structure evolution of UHMWPE macromolecules during the high-ratio hot-drawing process was studied by differential scanning calorimeter (DSC), wide-angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS) and other testing methods. The experimental results demonstrated that the UHMWPE/decalin spinning suspension was extruded from the spinneret hole to form a fine spinning flow, followed by the formation of the transitional-state fibers at different processing stages, and finally the ready-made fibers. The total drafting ratio of the UPE fibers after fabrication reached more than 600 times. The diameter of the single UPE filament was reduced to 5.66 μm with elevated drawing ratios. The crystal structure of the prepared UPE fibers was progressively improved, and the folding-chain crystals of fibers gradually transformed into extended-chain crystals. The mechanical properties of the UPE fibers were significantly improved. The fracture strength of the as-spun UPE fibers reaches 48.1 cN/dtex, which endows the fibers with specific characteristics such as ultra-fine denier and ultra-high strength.

Liquid-templated graphene aerogel electromagnetic traps.

For decades, the inherently reflective nature of metallic electromagnetic (EM) shields and their induced secondary EM pollution have posed significant challenges for sensitive electronics. While numerous efforts have been made to develop superior EM shielding systems, the issue of reflection dominancy in metallic substrates remains unresolved. Herein, we addressed this long-lasting obstacle by pairing metallic shields with ultra-lightweight (density of 3.12-3.40 mg cm-3) elastic anti-reflection aerogels, altering their shielding mechanism from dominant reflection (reflectance >0.8) to absorption (absorbance >0.7) by trapping EM waves inside the aerogel. The aerogel EM traps were generated using interfacial complexation, yielding engineerable filamentous liquid structures. These served as templates for aerogel creation through a follow-up process of freezing and lyophilization. The engineerable lossy medium of aerogels benefits from a multi-scale porous construct with the combined action of dielectric and conduction losses, highly dissipating the EM waves and minimizing the reflections. Notably, declining the diameter of aerogel filaments promoted its absorption dominancy, rendering it a potent dissipating medium for EM waves. Pairing a metallic substrate with filamentous aerogel EM traps has resulted in an exceptionally effective absorption-dominant shielding system, achieving absorbance levels between 0.70-0.81. This system offers a shielding effectiveness of 53-89 dB within the X-band frequency range. This innovation addresses a persistent issue in shielding science related to the reflective characteristics of metallic substrates, effectively inhibiting their induced EM reflections.

The route to achieve isotropy in 3D printing parts via Fused Filament Fabrication with Advanced Semicrystalline Thermoplastics

This review investigates the challenges of Additive Manufacturing using commodity, engineering, and advanced materials, both amorphous and semicrystalline. It explains the reasons behind the weaker mechanical performance of semicrystalline materials compared to amorphous polymers used in the 3D printing process. The performance of 3D printing is discussed to demonstrate the current position of additive manufacturing as one of the promising techniques meeting the requirements of the 5.0 Industrial Revolution, particularly in terms of delivering personalized products. The differences between amorphous and semicrystalline materials on a macromolecular level, including the strength of the single bond in the polymer backbone chain and the effect of electron donation to the backbone, are discussed. Interlayer imperfections are classified into several groups: moisture in the feedstock filament, inconsistent filament diameter, shrinkage of the deposited materials, and, most importantly, crystallization kinetics of semicrystalline materials. Finally, insights on how to achieve properties closer to an isotropic body when advanced semicrystalline materials are printed, in order to overcome layer-layer defects, are provided.

Structure–mechanical property relationships of 3D-printed porous polydimethylsiloxane films

Abstract Complex microstructures can be produced from different base materials by combining three-dimensional (3D) printing technology and ink formulations. The surface wettability of the 3D-printed porous polydimethylsiloxane (PDMS), particularly its superhydrophobic property, strongly depends on its physical structure. However, the mechanism underlying the effect of the microporous structure on the mechanical properties is not understood, which seriously constrains the structural–functional integration design of the 3D-printed superhydrophobic porous PDMS. To solve this problem, we studied the influence of the printing parameters on the mechanical properties in the compression and tension directions using a finite element method. The results showed that the load transfer path of the 3D-printed porous PDMS was along the overlapping area of the adjacent filaments. As the filament spacing decreased or the filament diameter increased, the elastic modulus of the porous PDMS was enhanced, improving its resistance to tensile and compressive deformation. A quantitative relationship was established between the relative densities of the porous PDMS films and their relative elastic moduli. This study provides theoretical guidance for the structural–functional integration design of 3D-printed superhydrophobic porous PDMS.

Pengaruh Sudut Part Build Orientation Z-Direction Terhadap Kuat Tarik Spesimen Uji Standar Astm D638 Type IV Menggunakan Filamen Pla+

This study will try to investigate variations in the angle of the Z-direction build part by using a 3D Printer with Fused Deposition Modeling (FDM) technology made from PLA + Sugoi. This study uses a 0.4mm nozzle with a Bowden type extruder. This study uses a PLA+ filament from the Sugoi brand with a nozzle of 0.4 mm, diameter filament 1,75 mm, 3D Printer with Fused Deposition Modeling (FDM) technology used is Creality Ender 3 V2 with process parameter settings in slicing software using a layer thickness of 0.30 mm, Top solid Layer 5, Bottom Solid Layer 5, Fill density 100%, cooling speed 100%, and flowrate 100%, nozzle temperature 205°C, and bed temperature 60°C. Variation in angle Part build Z-direction is proven to have a significant difference in Tensile strength with a difference of 10° resulting in a difference in Tensile strength of 15 MPa, where the highest tensile strength is 67.50 MPa with part build Z-direction at an angle of 80°, and the lowest tensile strength of 52.50 MPa with a Z-direction part build angle at an angle of 70°.

Synthesis, Processing, and Characterization of CNT Filaments for Printing of High-Performance Flexible Electronics

The rapid advancement of 3D printing technology has provided opportunities for exploring novel materials, such as carbon nanotubes (CNTs), that possess significant capabilities for improving electrical devices. CNTs exhibit remarkable conductivity and mechanical characteristics within the flexible electronics domain, rendering them an up-and-coming contender for propelling advancements in this discipline. The synthesis, processing, and characterization of CNT-based filaments play a crucial role in entirely using the capabilities of these materials for applications in flexible electronics. This work presents the CNT Filaments for Printing System (CNT-FPS), a holistic approach incorporating cutting-edge CNT manufacturing, filament processing, and material characterization methodologies. The CNT-FPS material exhibits distinctive characteristics, such as precise control over diameter management, elevated levels of purity, and remarkable dispersion of CNTs inside the polymer matrix. The CNT-FPS method exhibited superior performance in eight key metrics. These metrics include filament diameter (1.15 mm), surface morphology (8.75 µm), electrical conductivity (375.62 S/cm), tensile strength (61.24 MPa), Young's Modulus (13.45 GPa), thermal stability (340.75°C), crystallinity (48.75%), and wear rate (0.009 mm³/Nm). The findings of this study demonstrate a potentially fruitful direction for advancing the field of high-performance flexible electronics. The research provides a foundation for developing electrical devices that exhibit exceptional durability, adaptability, and functionality through the strategic enhancement of CNT synthesis, processing, and characterization techniques inside the CNT-FPS framework. These devices have immense potential for diverse applications like wearable technology, healthcare, and beyond.

Variation of effective filament diameter, irreversibility field, anisotropy, and pinning efficiency in Bi-2212 round wires

In recent years Bi2Sr2CaCu2O x (Bi-2212) received increasing attention due to its round wire multifilamentary architecture, a unique feature in high-Tc superconductor. In fact, round wires are preferable for magnet designs, including solenoids for nuclear magnetic resonance (NMR) or research purpose and accelerator magnets. However, due to the narrow over-pressure heat treatment conditions necessary to obtain high Jc and to the peculiar microstructure of Bi-2212 wires, a full understanding of the correlations between the different properties has not yet been developed. In this paper we investigate the effect of a vital part of Bi-2212 optimization, the maximum heat-treatment temperature T max in the range of 885 °C–896 °C, on the variations of Jc , effective filament diameter d eff, anisotropy γ, INTER- and intra-grain irreversibility fields and pinning energies U 0, all critical parameters in unravelling the complex mix of vortex pinning and connectivity that ultimately determines the critical current density. We found that d eff of the higher Jc wires heat-treated at lower temperature is much smaller than for the lower Jc wires. Moreover, a systematic increase of the irreversibility field and a decrease of the intrinsic Bi-2212 anisotropy underpins the higher Jc . The analysis of the pinning energies reveals that there is little sample-to-sample variation in the INTER-grain pinning, whereas in all samples the intra-grain pinning has an enhancement below ∼40–45 K becoming more and more evident with increasing Jc . These results suggest that the overall Jc performance are not only related to the wire microstructure and connectivity, which obviously affect the INTER-grain properties, but they are also intimately related to the intrinsic and intra-grain properties such as γ and U 0.

Development of HFCVD apparatus for synthesizing diamond films with low thermal budget

The electrical power consumption, which is approximately equal to the thermal budget, accounts for the majority of the total cost to synthesize diamond films by the hot filament chemical vapor deposition (HFCVD) apparatus. In this study, two strategies, visualizing as certain additional parts in the apparatus, are proposed for reducing the thermal budget and synthesis cost. Detailed effects are proven by the finite volume method (FVM) simulation, temperature measurement and deposition experiments, demonstrating that the reduction of thermal conductivity of the worktable (by changing the worktable material) and the insertion of the circular ring copper shielding will significantly contribute to the reduction of the heat dissipation and substrate temperature rise. Influences of major filament parameters on substrate temperature values and distributions are then clarified, suggesting that in order to control the substrate temperatures in a similar and reasonable range in the modified apparatus, the best choice is to synchronously reduce the filament diameter and the electrical power, while retaining the filament temperature still in a high level (around 2200 °C). Finally, the energy saving ratios are as high as 28.4% (experimental apparatus) and 27.4% (commercial apparatus), and the substrate temperature distributions can also be improved, guaranteeing the uniformity of as-deposited diamond films on mass substrates.

Non-contact online inspection method for the appearance diameter uniformity of chemical fiber filaments

As chemical fiber filaments diameter variation directly affects spinning quality, spinning condition monitoring becomes more and more important in an intelligent manufacturing environment. Firstly, based on the single-slit Fraunhofer diffraction model and the Babinet principle, the non-contact filaments diffraction model is developed to generate diffraction fringe patterns by irradiating chemical fiber filaments with He–Ne laser. Secondly, for the characteristics of diffraction fringe patterns, a segmentation mask window-based diffraction fringe center of gravity extraction method is proposed, and a zero-phase Butterworth low-pass filter is designed and applied to the diffraction light intensity curves to accurately extract the extreme points positions of the adjacent dark fringe and calculate the diameter information. Finally, the non-contact chemical fiber filaments appearance diameter online inspection experiment platform is built to carry out static and dynamic experiments of filaments. The experimental results show that the maximum absolute value of absolute error is less than 1.1 μm for static measurement and less than 10 μm for dynamic measurement.

Breakup regimes of the long-time dynamics of a finite-size air filament in a dense fluid

The long-time dynamics of a quiescent finite-size three-dimensional air filament in a static liquid is studied using three-dimensional numerical simulations. The two ends of the air filament retract under the effect of surface tension and form bulges. A long filament with the aspect ratio Γ = 30 is considered to trigger the end-pinching regime of the filament rupture. The study focuses on the effect of the Ohnesorge number, which relates viscous forces to inertia and surface tension forces. Depending on the value of the Ohnesorge number, two or three successive ruptures of the filament are observed. Wavy structures form at the interface of the air filament after the first rupture and lead to a subsequent breakup in the middle of the filament or in several places depending on the corresponding Ohnesorge number. The size distribution of the bubbles generated is provided and shows an average diameter twice as large as the initial diameter of the air filament. Microbubbles are generated, and their number is shown to increase when the Ohnesorge number decreases.

Tensile Properties of 3D Printed Recycled PLA Filament: A Detailed Study on Filament Fabrication Parameters

Polylactic acid (PLA), a biodegradable and biocompatible thermoplastic commonly utilized in 3D Printing filaments, undergoes changes in properties upon recycling. The objective was to elucidate the role of extrusion temperature and screw speed in modulating the quality of recycled PLA filament, as well as in controlling its dimensional attributes. Recycled PLA pellets (3D850D) were extruded using a single filament extruder machine within an extrusion temperature range of 145°C to 165°C and a screw speed varying from 2 rpm to 6 rpm. The extruded filaments were subsequently 3D printed into specimens adopting a 0° raster angle, line infill pattern, and a 100 percent infill density, then tested as per ASTM D638 mechanical standards. The study revealed a profound influence of extrusion parameters on the filament's ultimate tensile strength, yield strength, and diameter. Optimal extrusion conditions - 155°C and 5 rpm - resulted in maximum mechanical strengths, while the parameters yielding filament diameters closest to commercial standards were identified as 5 rpm and 155°C. These results under-score the possibility of optimizing the recycled PLA filament's properties through adept control of extrusion parameters. Consequently, this investigation supports the potential use of recycled PLA filament in the 3D printing industry as a sustainable and performance-efficient material, offering a tangible step towards environmentally friendly additive manufacturing practices.

Multi-Effects of Acute Salinity Stress on Osmoregulation, Physiological Metabolism, Antioxidant Capacity, Immunity, and Apoptosis in Macrobrachium rosenbergii.

Salinity stress can trigger a series of physiological changes. However, the mechanism underlying the response to acute salinity stress in Macrobrachium rosenbergii remains poorly understood. In this study, osmoregulation, physiological metabolism, antioxidant capacity, and apoptosis were examined over 96 h of acute salinity stress. Hemolymph osmolality increased with increasing salinity. After 48 h of salinity exposure, the glucose, triglycerides, total protein, and total cholesterol contents in two salinity stress groups (13 and 26‱ salinity) were significantly lower than those in the 0‱ salinity group. The highest levels of these parameters were detected at 6 h; however, superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) were the lowest at 96 h in the 13‱ salinity group. The activity of immunity-related enzyme alkaline phosphatase (AKP) showed a decreasing trend with increasing salinity and remained at a low level in the 26‱ salinity group throughout the experiment. No significant differences were observed in aspartate aminotransferase (AST), alanine aminotransferase (ALT), or lysozyme (LZM) among the three treatments at 96 h. After 96 h of salinity treatments, the gill filament diameter significantly decreased, and a more pronounced terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive signal was detected in the 13‱ and 26‱ groups compared to that in the 0‱ group. Expression levels of apoptosis-related genes, including Cysteine-aspartic acid protease 3 (Caspase 3), Cysteine-aspartic acid protease 8 (Caspase 8), Cytochrome c (Cyt-c), tumor suppressor gene (P53), Nuclear factor kappa-B (NF-κB), and B cell lymphoma 2 ovarian killer (Bok) were significantly higher in the 26‱ salinity group than in the other groups at 24 h, but lower than those in the 0‱ salinity group at 96 h. Cyt-c and P53 levels exhibited a significantly positive relationship with MDA, AST, and LZM activity during salinity stress. In the 13‱ salinity group, Bok expression was significantly correlated with SOD, T-AOC, AKP, acid phosphatase, and LZM activity, whereas in the 26‱ group, the AST content was positively correlated with Caspase 8, Cyt-c, and P53 expression. A significant negative relationship was observed between Caspase 3 expression and catalase (CAT) activity. These findings provide insight into the mechanisms underlying the response to acute salinity stress and will contribute to improving M. rosenbergii aquaculture and management practices.

Closing the Loop: Toward Sustainable 3D Print Recycling in the Clinic

THREE-DIMENSIONAL (: 3D) printing is becoming ubiquitous in Radiation Therapy resulting in large amounts of plastic waste generated. We report on the feasibility, workflows, material properties and cost effectiveness of 3D print recycling to increase sustainability of 3D printing in clinics. Polylactic acid (PLA) prints were recycled using a consumer-grade recycling system consisting of i) plastic shredder to granulate used prints ii) heated extruder to melt material into filament iii) fan-cooled path for rapid cooling iv) spooling rig and v) pelletizer to cut filament into more regularized pellets as input material for step ii). The recovery percentage of material was characterized after each step by weighing inputs/outputs; timing and workloads were also recorded. Resulting recycled filaments were characterized in diameter and tensile strength and were compared between two different extruder nozzle configurations and with vs without pelletization to find an optimal recycling process. Recycled filament was finally used to create clinical items and evaluated. Lastly, a cost analysis over the past 1 year of recycling use was performed to determine the cost effectiveness of the recycling system. PLA prints were recycled with an overall efficiency of 79.3 ± 12.2% (standard deviation) between color batch runs. The best recycled filament quality was produced using the pelletization process and wider 3.25mm extruder nozzle. Relative to new filament, tensile strength testing showed recycled filament strength was 79% vs 70% (pelletized vs unpelletized) and 86% vs 60% (3.25mm vs 2.85mm nozzle). Extrusion and spooling procedures proved difficult to optimize, requiring lots of operator supervision (∼45 minutes per spool, mean 475g) and achieved a best filament diameter of 2.85 ± 0.09mm. A cost analysis shows that without accounting for operator time, it would require over 25 years to recoup the cost of the recycling system. Over the past 1-year, clinical 3D printing at our site consisted of 40 patient boluses and 25 electron cutouts, consuming about 6.5kg of PLA. Due to infection control concerns only 35% of this material was eligible for recycling, however 3.5 times that amount was collected from other printing activities. Recycling reduced new filament use by 56% ($470). Recycling workflows proved difficult to streamline and resulted in filament diameter that was marginally outside common industry standards and about 20% less strong but deemed adequate for clinical printing. Although the cost savings analysis indicates a poor return on investment, increasing the scale of the operation would be beneficial. To achieve this, we plan to recycle PLA boluses after disinfection and solicit other clinics in our hospital network and local 3D printing hobbyist community to recycle their prints.

Non-destructive evaluation of melt-extruded part quality using in situ data

PurposeThis study aims to collect real-time, in situ data from polymer melt extrusion (ME) 3D printing and use only the collected data to non-destructively identify printed parts that contain defects.Design/methodology/approachA set of sensors was created to collect real-time, in situ data from polymer ME 3D printing. A variance analysis was completed to identify an “acceptable” range for filament diameter on a popular desktop 3D printer. These data were used as the basis of a quality evaluation process to non-destructively identify spatial regions of printed parts in multi-part builds that contain defects.FindingsAnomalous parts were correctly identified non-destructively using only in situ collected data.Research limitations/implicationsThis methodology was developed by varying the filament diameter, one of the most common reasons for print failure in ME. Numerous other printing parameters are known to create faults in melt extruded parts, and this methodology can be extended to analyze other parameters.Originality/valueTo the best of the authors’ knowledge, this is the first report of a non-destructive evaluation of 3D-printed part quality using only in situ data in ME. The value is in improving part quality and reliability in ME, thereby reducing 3D printing part errors, plastic waste and the associated cost of time and material.

Indications for a genetic basis for big bacteria and description of the giant cable bacterium Candidatus Electrothrix gigas sp. nov.

Bacterial cells can vary greatly in size, from a few hundred nanometers to hundreds of micrometers in diameter. Filamentous cable bacteria also display substantial size differences, with filament diameters ranging from 0.4 to 8 µm. We analyzed the genomes of cable bacterium filaments from 11 coastal environments of which the resulting 23 new genomes represent 10 novel species-level clades of Candidatus Electrothrix and two clades that putatively represent novel genus-level diversity. Fluorescence in situ hybridization with a species-level probe showed that large-sized cable bacteria belong to a novel species with the proposed name Ca. Electrothrix gigas. Comparative genome analysis suggests genes that play a role in the construction or functioning of large cable bacteria cells: the genomes of Ca. Electrothrix gigas encode a novel actin-like protein as well as a species-specific gene cluster encoding four putative pilin proteins and a putative type II secretion platform protein, which are not present in other cable bacteria. The novel actin-like protein was also found in a number of other giant bacteria, suggesting there could be a genetic basis for large cell size. This actin-like protein (denoted big bacteria protein, Bbp) may have a function analogous to other actin proteins in cell structure or intracellular transport. We contend that Bbp may help overcome the challenges of diffusion limitation and/or morphological complexity presented by the large cells of Ca. Electrothrix gigas and other giant bacteria. IMPORTANCE In this study, we substantially expand the known diversity of marine cable bacteria and describe cable bacteria with a large diameter as a novel species with the proposed name Candidatus Electrothrix gigas. In the genomes of this species, we identified a gene that encodes a novel actin-like protein [denoted big bacteria protein (Bbp)]. The bbp gene was also found in a number of other giant bacteria, predominantly affiliated to Desulfobacterota and Gammaproteobacteria, indicating that there may be a genetic basis for large cell size. Thus far, mostly structural adaptations of giant bacteria, vacuoles, and other inclusions or organelles have been observed, which are employed to overcome nutrient diffusion limitation in their environment. In analogy to other actin proteins, Bbp could fulfill a structural role in the cell or potentially facilitate intracellular transport.