High Magnification Scanning Electron Microscopy Research Articles

Optimized Design of Material Preparation for Cotton Linters-Based Carbon Black Dispersion Stabilizers Based on Response Surface Methodology.

Carbon black particles possess dimensions on the nanometer or sub-nanometer scale. When utilized, these particles have a tendency to aggregate, which compromises their stability under storage conditions. To address this issue, a dispersant was prepared using cotton short fibers as raw materials through etherification and graft polymerization with acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as raw materials. The dispersant was then used to disperse carbon black to test its dispersing performance. A response surface optimization test was utilized to ascertain the influence of AMPS monomer mass, AM monomer mass, and potassium persulfate (KPS) initiator mass on the dispersibility of carbon black during dispersant preparation, and a set of optimal preparation conditions were obtained. The dispersion stability of carbon black in water was assessed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), elemental analysis (EA), thermogravimetric analysis (TG), zeta potential analysis, high magnification scanning electron microscopy (SEM), and contact angle measurements. Results revealed that the optimum mass ratio of carboxymethyl cellulose (CMC) to AMPS to AM was 1:0.69:1.67, with the KPS initiator comprising 1.56% of the total monomer mass. By incorporating the dispersant at a concentration of 37.50%, the particle size of carbon black particles was observed to decrease from 5.350 μm to 0.255 μm, and no agglomeration of carbon black particles occurred even after 3 weeks of storage.

Segmentation and Classification of Fission as Pores in Reactor Iirradiated Annular U[sbnd]10Zr Metallic Fuel Using Machine Learning Models

Metallic fuels, particularly U10Zr, are promising candidates for next-generation sodium-cooled fast reactors. Irradiation of nuclear fuels in reactors can lead to the formation of solid and gas fission product which subsequently forms microstructural pores, deteriorating fuel performance. Due to the massive amount of pores and complex phases formed, a quantitative description of fission gas pores is not yet available, preventing the development of microstructure-informed fuel performance modeling for fuel qualification. This paper applied a pre-trained deep learning model to ∼10,260 high magnification scanning electron microscopy images. This method increased the accuracy of fission gas pore segmentation and allows statistical features to be extracted which cannot be achieved manually. A pre-trained decision tree model worked on the segemenation resutls and further classified the pores into different categories to produce a correlation between the pores, movement of lanthanides, and temperature gradient during irradiation. This paper emphasizes the potentials of machine learning models to accelerate fuel research, development, and qualification for advanced reactors.

Embryonic and Early Larval Development of the Pacific Razor Clam (Siliqua patula).

AbstractThe Pacific razor clam, Siliqua patula (Sugpiaq: Cingtaataq, Dixon, 1789), is vital to commercial, recreational, and subsistence fisheries across the Pacific Northwest Coast of North America. Despite the species' status as one of the most popular shellfish species harvested in the Pacific Northwest, British Columbia, and Alaska, its larval development has never been fully characterized. Generating a developmental times series, and describing development fully, is crucial for guiding targeted management, developing a mariculture strategy for the species, and providing a more pointed avenue for studies examining the response of S. patula to ocean change. This study presents the first photographic documentation of larval development in S. patula, including the timing of key transitions during embryogenesis and early larval development. Scanning electron microscopy revealed that the larval shell forms via a concretion, a process typically documented in early gastropod development. This novel characterization is pertinent, as it conveys the need for the inclusion of alternative bivalve development processes, such as a concretion, in bivalve research. This study also compared development in S. patula to a global assortment of bivalve species, including two other members of the Pharidae family, determining that the timing to D-veliger and trochophore stages was similar to the majority of bivalves surveyed. While bivalve response to climate change is a topic of great interest, not all species of concern have undergone comprehensive developmental assessments, a requisite benchmark for designing climate change studies that examine early life history sensitivity to such changes. This research supports the use of comprehensive developmental studies as prerequisites for designing climate change experimentation, establishes the necessity of high-magnification and high-resolution scanning electron microscopy within developmental assessments, and provides information about the development of a cornerstone bivalve species.

Late CambrianPywackiais a cnidarian, not a bryozoan: Insights from skeletal microstructure

AbstractThe phylum Bryozoa had long been the only major phylum unknown from the Cambrian and by inference the Cambrian Explosion of biodiversity. When described in 2010 as a late Cambrian cryptostome bryozoan,Pywackia baileyiLanding in Landing et al., 2010 became the oldest known bryozoan (early Cambrian bryozoans have since been described). Controversy remains about the phylum-level identification ofPywackiaLanding in Landing et al., 2010—one study proposed an interpretation ofPywackiaas an octocoral. No previous studies of the skeletal microstructure ofPywackiahave employed the analysis of petrographic thin sections and high-magnification scanning electron microscopy. These two methods, with the addition of data from previous studies, are employed in this analysis of skeletal microstructure, a feature often important for higher-level taxonomic identification. Although many candidate groups were considered,Pywackia's distinctive pillar and laminae, porous skeleton like many Cnidaria, topology of the body walls, and growth of modules are consistent with a cnidarian affinity.Pywackiaskeletons with primary microstructure were 100% phosphate mineral and were collected from a setting of pervasive phosphatic replacement, which leaves uncertainty as to the original skeletal composition.Pywackiais not assigned here to a cnidarian class and likely represents an early, rare, short-lived cnidarian evolutionary group.

Analysis of composition and microstructure of diatom frustules in mud on the coast of Boryeong- city, South Korea

The microstructure of diatom frustules found in mud sediments along the coast of Boryeong- city, South Korea, was observed using a scanning electron microscopy (SEM), and the constituent elements of diatoms were analyzed using energy-dispersive X-ray spectroscopy (EDS). Diatom frustules and clay minerals were present in the SEM images of the mud powder. High-magnification SEM images revealed that the surface of the frustules contained identically shaped circular pores, measuring 1 μm in diameter, arranged at regular intervals. This study revealed that the diatom shell fragments in the mud powder ranged in size from 3 to 30 μm, with an average thickness of approximately 2.5 μm. The elements Si, Al, Fe, K, Na, Mg, and Ti were detected while analyzing the frustule constituents, with Si being the primary component with the highest content.

Magnetron Sputtering of Transition Metals as an Alternative Production Means for Antibacterial Surfaces.

In the light of the SARS-CoV-2 pandemic and growing numbers of bacteria with resistance to antibiotics, the development of antimicrobial coatings is rising worldwide. Inorganic coatings are attractive because of low environmental leakage and wear resistance. Examples for coatings are hot metal dipping or physical vapor deposition of nanometer coatings. Here, magnetron sputtering of various transition metals, such as gold, ruthenium and tantalum, was investigated. Metal films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDX). We investigated the growth of Pseudomonas aeruginosa isolated from household appliances on different sputter-coated metal surfaces. The fine-grained nanometric structure of these metal coatings was between 14 nm (tantalum) and 26 nm (gold) and the roughness was in a range of 164 pm (ruthenium) to 246 pm (gold). Antibacterial efficacy of metal surfaces followed the order: gold > tantalum > ruthenium. Interestingly, gold had the strongest inhibitory effect on bacterial growth, as analyzed by LIVE/DEAD and CFU assay. High-magnification SEM images showed dead bacteria characterized by shrinkage induced by metal coatings. We conclude that sputtering might be a new application for the development of antimicrobial surfaces on household appliances and or surgical instruments.

Surface integrity studies on ZrB2 and graphene reinforced ZrB2 ceramic matrix composite in EDM process

Zirconium diboride is a potential ceramic for high temperature applications because of its combination of properties, such as very high melting point, high hardness, elevated temperature strength, good thermal and electrical conductivity. Although the near net shape components are made from this material, machining is required to create additional features for the application requirements. This ceramic's high hardness and low fracture toughness make it very difficult to use the conventional processes for machining. The good electrical conductivity of this ceramic makes electrical discharge machining (EDM) the preferred machining process. This paper presents the surface and sub-surface modifications during Wire cut EDM (WEDM) and EDM of ZrB2 an ultra high temperature ceramic (UHTC) and ZrB2-GNP (ceramic matrix composite with 7 vol% Graphene Nano Platelets) along with the surface characterization of the copper electrode (EDM tool). Scanning Electron Microscope (SEM) with Energy Dispersive Spectroscopy (EDS) and Raman spectroscopy (for GNPs) were used to characterize the melt-solidified layer and the recrystallized region. The presence of micro cracks and pores was observed in the melt-solidified layer. Growing dendrites of ZrB2 were observed in the high magnification SEM images of the melt-solidified layer surface. Under the melt-solidified layer, a recrystallized fine grain structure was observed with reduced porosity compared to the rest of the bulk. After the WEDM of ZrB2-GNP (7 vol%), the stacks of cut GNP were retained, whereas GNPs were damaged after EDM The end surface of the copper electrode showed the partial deposition of ZrB2 and the formation of a micro scale pattern on it. The effect of peak current and pulse ON time on surface roughness (Sa), material removal rate (MRR) and relative tool wear (%) were studied for ZrB2-GNP (7 vol%) The results indicated that the surface roughness (Sa), MRR and the relative tool wear (%) increase with increasing peak current. The rise in pulse ON time also increases surface roughness (Sa) and MRR but reduces the relative tool wear rate (%)

Scanning electron microscopy (SEM) and macroscopic analysis of immature human permanent molar immersion in hydrochloric acid (HCL, 38%)

Recent literature indicates the destruction of human remains using hydrochloric acid (HCl, 38%) is often attempted to obscure the identity of victims or as a disposal method. Dentition are informative in an investigation where acid is used as a means of body disposal, as teeth are more likely to survive intact. Importantly, researchers studying acid immersion have not observed immature dentition, nor have they analyzed immature acid-treated teeth using scanning electron microscopy (SEM). This study analyzes the effects of HCl on immature human molars, with two goals: understanding the timing and nature of physical changes to immature molars caused by HCl immersion, and aiding in the identification and age determination of dental tissues partially or nearly completely destroyed using HCl.Our results indicated that immature human molars immersed in HCl follow a pattern of physical changes and decrease in weight as they dissolve similar to mature molars, although the timing of dissolution is affected by their smaller size and incompletely developed roots in a predictable way. With less root material present and an open root tip, we observed that HCl can more quickly penetrate the pulp cavity of immature molars. The mobile SEM images indicated immature and mature molars immersed in HCl exhibit similar changes at the microscopic level. Immature molars treated with HCl for over 18 h exhibited cracking features similar to those visible on mature molars that were difficult to differentiate from similar features on untreated teeth (both mature and immature) when images were taken at 3,000x or less. The appearance of features such as peeling layers and lamination at high magnification (6000x) were visible on both acid-treated mature and immature molars, but were not visible on untreated molars at the same level of magnification.By observing changes in the enamel and pulp cavity, it was possible to determine whether third molars were immature until approximately 18 h immersed in acid. At 42 h, it was no longer possible to determine whether the molars were immature. However, they were still easily identifiable as human teeth. In situations where teeth may no longer be identifiable macroscopically, we found that the laminating and peeling features observed on high magnification SEM imagery can be useful in characterizing acid treatment even on very small fragments of dental remains, potentially allowing investigators to determine if acid was used as a disposal method.

Multi-analytical study of the archaeological leather discovered near the medieval Oratea fortress

Recent archaeological excavations made on the plateau located east of the medieval fortress at Oratea (Podu Dâmboviţei, Argeş County) evidenced a fortified position of the Roman Age. Among other finds there is a relatively large leather fragment, belonging to the earliest phase (beginning of the second century AD). This discovery is extremely rare since suitable preservation conditions for leather are rarely meet in the specific soil and climate conditions in Romania. The contact with atmosphere induced sudden dehydration and consequent fragmentation of leather, which required a multi-analytical approach to extract useful information about its degradation condition. A combination of molecular (Fourier transform infrared spectroscopy in attenuated total refection mode, FTIR-ATR) and elemental (X-ray fluorescence, XRF) spectroscopic techniques with micro differential scanning calorimetry (micro-DSC) and scanning electron microscopy (SEM) was applied to this purpose. FTIR-ATR analysis allowed us to detect gelatin on the samples’ surface based on the collagen spectral components. Collagen extended de-tanning, gelatinisation and conversion into amorphous structures was quantified by microDSC. The alterations of leather microstructure and morphology were observed by high magnification SEM. XRF analysis also provided the elemental composition of soil. Overall, the archaeological samples shown extremely high fragility and the tendency to turn into powder on drying. This behaviour is due to the gelatinous-amorphous structure of leather strengthened only by the mineral components of the soil. Given the extremely high risk of loss, the authors recommend the application of a consolidation method based on halloysite and other nanoclays incorporation with utmost urgency.

In-situ SEM cyclic nanoindentation of pre-sintered and sintered zirconia materials

Efficient diamond machining of zirconia requires a comprehensive understanding of repetitive diamond indentation mechanics. This paper reports on in-situ cyclic nanoindentations of pre-sintered and sintered zirconia materials performed inside a scanning electron microscope (SEM). In-situ SEM imaging of cyclic indentation processes and high-magnification SEM mapping of indentation imprints were conducted. The elastic and plastic behaviors of pre-sintered and sintered zirconia materials were investigated as a function of the cyclic nanoindentation number using the Sakai and Sakai-Nowak models. For pre-sintered zirconia, cyclic nanoindentation induced quasi-plastic deformation, causing localized agglomeration of zirconia crystals with microcracks and large cracking along the indentation edge. Severely compressed, fragmented, and pulverized zirconia crystals and smeared surfaces were also observed. For sintered zirconia, shear bands dominated quasi-plastic deformation with the formation of edge pile-ups and localized microfractures occurred at indentation apex and diagonals. All elastic and plastic behaviors for pre-sintered and sintered zirconia materials revealed significantly microstructure-dependent. Pre-sintered zirconia yielded significantly lower contact hardness, Young's moduli, resistance to plasticity, elastic deformation components, and resistance to machining-induced cracking, and higher elastic and plastic displacements than sintered state. Meanwhile, all the behaviors for the two materials were independent from the cyclic nanoindentation number. A model was proposed for cyclic nanoindentation mechanics, revealing their cyclic indentation-induced microstructural changes in the two zirconia materials. This study advances the fundamental understanding of nanoindentation mechanics of zirconia materials.

Effect of substrate–induced localized stress on the combustion properties of Al/CuO reactive multilayer films

Reactive multilayer films are a high energy dense configuration for energetics widely studied for various pyrotechnic applications. The objective of this study is to investigate the influence of substrate–induced localized stress on the combustion properties of Al/CuO reactive thin films. Square microbumps are patterned on glass substrates to serve as embedded stressor elements. Stress-induced structural or morphological changes of the materials deposited around the microbumps are characterized using high-magnification transmission and scanning electron microscopy, providing simultaneous nanometer imaging resolution and detailed chemical analysis. The structural and chemical changes (appearance of reactant intermixing and voids) around the microbumps modify the energetic reservoir and the thermophysical properties of the film. The heat of reaction, the flame temperature and the effective thermal conductivity of the film are altered (loss of ∼15%), leading to a global decrease in the material reactivity. The flame velocity of the film deposited on the substrate with microbumps drops by 9.2%, 32.4% and 48.7% for microbump heights of 0.15, 0.35 and 0.83 µm, respectively. This work helps deepen the understanding of the effect of stress-induced strain on reactive film combustion properties and provides perspectives for controlling the reaction of reactive thin films by tailoring the strain distributions within the films.

The Terrestrial Plastisphere: Diversity and Polymer-Colonizing Potential of Plastic-Associated Microbial Communities in Soil.

The concept of a ‘plastisphere microbial community’ arose from research on aquatic plastic debris, while the effect of plastics on microbial communities in soils remains poorly understood. Therefore, we examined the inhabiting microbial communities of two plastic debris ecosystems with regard to their diversity and composition relative to plastic-free soils from the same area using 16S rRNA amplicon sequencing. Furthermore, we studied the plastic-colonizing potential of bacteria originating from both study sites as a measure of surface adhesion to UV-weathered polyethylene (PE) using high-magnification field emission scanning electron microscopy (FESEM). The high plastic content of the soils was associated with a reduced alpha diversity and a significantly different structure of the microbial communities. The presence of plastic debris in soils did not specifically enrich bacteria known to degrade plastic, as suggested by earlier studies, but rather shifted the microbial community towards highly abundant autotrophic bacteria potentially tolerant to hydrophobic environments and known to be important for biocrust formation. The bacterial inoculates from both sites formed dense biofilms on the surface and in micrometer-scale surface cracks of the UV-weathered PE chips after 100 days of in vitro incubation with visible threadlike EPS structures and cross-connections enabling surface adhesion. High-resolution FESEM imaging further indicates that the microbial colonization catalyzed some of the surface degradation of PE. In essence, this study suggests the concept of a ‘terrestrial plastisphere’ as a diverse consortium of microorganisms including autotrophs and other pioneering species paving the way for those members of the consortium that may eventually break down the plastic compounds.

The influence of cut direction and process parameters in wire electrical discharge machining of carbon fibre\u2013reinforced plastic composites

The paper details a comprehensive experimental investigation on the influence of operating parameters and cut direction (parallel and perpendicular to fibre orientation) when wire electrical discharge machining (WEDM) unidirectional CFRP composites using zinc-coated brass wire (0.25-mm diameter). A Taguchi L18 fractional factorial orthogonal array considering four variable parameters including open voltage, ignition current and pulse-on time as well as pulse-off time was carried out for each cut direction. Results showed that a ~ 16% increase in maximum material removal rate was achieved when machining parallel to fibre direction (2.41 mm3/min) compared to cutting perpendicular to the fibres (~ 2.08 mm3/min), which was attributed to the higher electrical conductivity of the workpiece along the fibre length leading to greater discharge energies. This however resulted in relatively larger average kerf widths and poorer workpiece surface roughness (Sa) caused by the Joule heating effect. Workpieces machined parallel to fibre direction were generally free of any major edge defects, in contrast to severe delamination observed on both the top and bottom surfaces of specimens cut perpendicular to fibre orientation. High-magnification scanning electron microscopy of the machined surfaces revealed the presence of adhered resin material, fibre cracking, cavities/gaps in the matrix phase and interlayer cracks on most of the samples analysed, with damage severity dependent on the operating parameters and cut direction.

Thin films of formamidinium lead iodide (FAPI) deposited using aerosol assisted chemical vapour deposition (AACVD)

Formamidinium lead iodide (CH(NH2)2PbI3, FAPI) thin films have been deposited on glass substrates at 150 °C using ambient pressure aerosol assisted chemical vapour deposition (AACVD). The films have been analysed by a range of techniques including powder X-ray diffraction (pXRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and UV–Vis–NIR absorption spectroscopy. Sharp reflections in the pXRD pattern can be indexed to the α-phase of FAPI which confirms the crystallinity of the as-deposited film and reveals a preferred growth orientation along the (002) plane with respect to the substrate. High magnification SEM images show that the thin film is comprised of a network of intimately connected FAPI crystallites which form a mesoporous architecture. EDX mapping of lead and iodine emission peaks show that the Pb and I within these films are spatially co-localised. Optical measurements show as-deposited FAPI films have absorption onsets in the near infra-red with a direct bandgap value of 1.46 eV, suitable for single junction solar cells. Four-point probe measurement of as deposited films show that the electrical conductivity (σ) of the FAPI thin film is 5.2 × 10–7 S/cm, which is similar to FAPI thin films deposited by spin coating technique.

Controlled Synthesis of Porous Carbon Nanostructures with Tunable Closed Mesopores via a Silica-Assisted Coassembly Strategy

Controllable fabrication of mesoporous carbon nanoparticles (MCNs) with tunable pore structures is of great interest, due to the remarkable effect of pore structure on electrochemical performance o...

Effect of tool geometry in dissimilar Al-Steel Friction Stir Welding

Aluminum-Steel joining is an example of a multi-material design. An amalgamation of both the material is very beneficial, yet they pose their set of difficulties in joining due to a significant difference in properties. Solid-state joining processes such as friction stir welding are beneficial in avoiding fusion and formation of a thick intermetallic layer in the Al-steel joint. Critical control of process parameters and tool geometry is essential in friction stir welding to attain a reasonably sound joint. In present work, butt welding of low carbon steel with Aluminum 5052 alloy is performed with the use of three different tools. Progressive refinement in the geometry of tools was done to achieve the optimized dimensions of the tool. The weld joints obtained from various tools were compared based on heat generation. The joints were characterized based on peak temperature achieved, tensile strength, and the number of steel fragments in the Al matrix through micrographs. The weld joint was observed under an optical microscope and Field emission scanning electron microscope (FESEM) for quantification of intermetallic compounds (IMC) layer. Energy-dispersive X-ray spectroscopy (EDX) and XRD analysis were performed to investigate the phase and composition of the IMC layer. The fractured surface under tensile loading was observed under high magnification scanning electron microscope. The tool with a shoulder diameter of 13 mm and a cylindrical pin was found to be optimized for its minimum heat generation and strongest weld joint formation with a minimum number of void-causing steel fragments.

Multistage Self-Assembly Strategy: Designed Synthesis of N-doped Mesoporous Carbon with High and Controllable Pyridine N Content for Ultrahigh Surface-Area-Normalized Capacitance

Nitrogen doping could improve the performance of carbon materials in electrocatalysis, CO2 adsorption, and energy storage. [1]However, the control of the doping type and the amount of nitrogen (N)-...

Gigapixel-like imaging strategies for dental anthropology: Applications for scientific communication and training in digital image analysis

Gigapixel and gigapixel-like (GPL) imaging strategies are a powerful means of communicating scientific results of visual observations in academic and public spheres. GPL images are made from a photomosaic of multiple, adjacent extended focus images, which allows users to “pan and zoom” across a surface to document or analyze specific features. Microscopic approaches using GPL imaging strategies are gaining popularity in use-wear analyses of lithics and bone implements but have not been applied to the study of human skeletal or dental remains. Here we present three examples of GPL imaging using scanning electron microscopy (SEM) of the dental surfaces of teeth excavated from the Chalcolithic contexts of El Mirador Cave (Sierra de Atapuerca, Burgos, Spain). Numerous common features are identifiable in the GPL examples from El Mirador Cave that include wear features (e.g., enamel chipping, labial striations), perikymata, calculus deposits, hypoplasias, and postmortem taphonomic features. One GPL example shows a less-commonly documented pair of lingual surface features (i.e., lingual surface attrition of the maxillary anterior teeth [LSAMAT] and a continuous cingular lesion [CCL]) for which co-occurrence has not been previously documented. Another example using a combination of GPL, macrophotography, and additional high magnification SEM images shows a case of chemical erosion on a labial surface of the tooth - a seldom documented form of wear in bioarchaeological contexts. This latter example also highlights the complementary nature of SEM (and GPL) with digital macrophotography for documenting dental wear features. Together, these examples illustrate the utility of GPL images of dental surfaces for didactic purposes and analysis.

Microstructure characteristics and mechanical behaviour of a selective laser melted Inconel 718 alloy

In this study, an Inconel 718 alloy was prepared by selective laser melting (SLM) with a pre-alloyed powder, and the microstructure and mechanical behaviour of the fabricated parts were studied. First, the settled layer structure, composed of several interlaced "perlage" molten pools and molten channels, was captured by low-magnification optical microscopy (OM), and the formation mechanism was revealed by the Gaussian heat source distribution characteristics of the laser source used for the SLM fabrication. Second, high-magnification scanning electron microscopy (SEM) captured the different crystal structures in different fabricated positions; meanwhile, the "cross-border growth phenomenon" along the forming direction and the "growth and distribution characteristics of the crystal" in the radial direction (perpendicular to the forming direction) were also captured. By introducing the component super-cooling theory, the growth mechanism of crystal structures in different positions under a multi-dimensional temperature gradient heat conduction coupling mode is proposed. Finally, combined with transmission electron microscopy (TEM) and a mechanical properties test, it was found that the mechanical properties were between those of parts fabricated by casting and those by forging because the γ" phase and γ' phase were distributed in the crystal, while the carbide phase and Laves phase were distributed in the intercrystal region.

Effect of Gas Flow Rates on Quality of Aerosol Jet Printed Traces With Nanoparticle Conducting Ink

AbstractThis paper focuses on the influence of carrier gas flow rate (CGFR) and sheath gas flow rate (SGFR) on the quality of conductive traces printed with nanoparticle inks using aerosol jet printing (AJP). This investigation was motivated by previous results of two AJP specimens that were printed at different gas flow rates and yielded significantly different thermal cycling durability lifetimes. A parametric sensitivity study was executed by printing and examining serpentine trace structures at 15 different combinations of CGFRs and SGFRs. The analysis included quantifying the trace's macroscale geometry, electrical properties, and micromorphological features. Interesting macroscale results include an increase in effective conductivity with increasing CGFR. At the microscale, image processing of high magnification scanning electron microscope (SEM) images of the printed traces revealed that agglomerations of silver clusters on the surface of traces became coarser at higher CGFR and also that agglomerates in the bulk were finer than those on the surface. Crystalline silver deposits were observed at all flow rates. In addition, cross sectioning of the printed traces showed higher incidences of buried cohesive cracking at higher gas flow rates. These cohesive cracks reduce the robustness of the traces but may not always be visible from the surface. The degree of cohesive cracking was seen to be broadly correlated with the coarseness of the surface agglomerates, thus suggesting that the coarseness of surface agglomerates may provide a visible surrogate measure of the print quality. The results of this study suggest that print quality may degrade as gas flow rates increase.