Search results for "printing"
showing 10 items of 532 documents
Cold gas dynamic spray additive manufacturing today: Deposit possibilities, technological solutions and viable applications
2017
This paper reports the current potentials of cold gas dynamic spraying (CGDS). CGDS has been significantly developed to produce several functional solutions categorized as follows: deposits with a single powder nature, composites-based deposits, nanotechnological deposits and hybrid coating/substrate assemblies. CGDS process has improved in proficiency and is still gaining attention from scientists and industry. Covering a wide range of materials, both standard and advanced, this additive manufacturing process offers substantial applications for surface functionalization, structural or dimensional restoration, bulk production providing specific material properties, and art/decoration. Progr…
ASSESSING TRACE ELEMENT (DIS)EQUILIBRIUM AND THE APPLICATION OF SINGLE ELEMENT THERMOMETERS IN METAMORPHIC ROCKS
2018
Abstract Empirical and experimental calibration of single element solubility thermometers, such as Zr-in-rutile, Zr-in-titanite, Ti-in-zircon, and Ti-in-quartz, within the past 13 years has greatly expanded our ability to assess the pressure and temperature conditions of individual minerals associated with specific textures in metamorphic rocks. Combined with advances in in situ techniques for analyzing trace concentrations, this has led to an increase in the combined use of single element thermometers, geochronometers, and isotope ratios, often simultaneously, in metamorphic minerals. Here we review the calibration and application of single element thermometers at the pressure and temperat…
Shear zone junctions: Of zippers and freeways
2017
Abstract Ductile shear zones are commonly treated as straight high-strain domains with uniform shear sense and characteristic curved foliation trails, bounded by non-deforming wall rock. Many shear zones, however, are branched, and if movement on such branches is contemporaneous, the resulting shape can be complicated and lead to unusual shear sense arrangement and foliation geometries in the wall rock. For Y-shaped shear zone triple junctions with three joining branches and transport direction at a high angle to the branchline, only eight basic types of junction are thought to be stable and to produce significant displacement. The simplest type, called freeway junctions, have similar shear…
Evaluating ice fabrics using fabric analyser techniques in Sørsdal Glacier, East Antarctica
2011
AbstractIce cores (∼4 m long) obtained from areas of different surface velocities near the terminus of Sørsdal Glacier, East Antarctica, have been investigated using two versions of a fabric analyser (G50). In sections parallel to the flow plane, the microstructure is typically interlocking with elongate grains that parallel air-bubble elongation, X, reflecting their development in an earlier ductile regime. The c-axis fabric patterns vary with respect to X and vary from single–double maxima to asymmetric small-circle girdles oblique to the planar foliation, which can be attributed to a simple shear regime. The siteto-site variations in the c-axis patterns can be related to areas of differe…
Production of extracellular fructans by Gluconobacter nephelii P1464.
2015
UNLABELLED Bacterial extracellular fructans, known as levans, have potential applications in food, pharmaceutical and cosmetic industries and high fructan producing strains could contribute into the cost reduction and more extensive commercial usage of them. An acetic acid bacteria (AAB) isolate P1464 was obtained from the Microbial Strain Collection of Institute of Microbiology and Biotechnology, University of Latvia and identified as Gluconobacter nephelii by DNA-DNA hybridization and the formation of extracellular fructans by this strain was confirmed. Isolated extracellular fructose polymers were characterized using FT-IR spectroscopy and the structural features of fructan appeared as s…
Hydrogel‐Based 3D Bioprinting for Bone and Cartilage Tissue Engineering
2020
As a milestone in soft and hard tissue engineering, a precise control over the micropatterns of scaffolds has lightened new opportunities for the recapitulation of native body organs through three dimentional (3D) bioprinting approaches. Well-printable bioinks are prerequisites for the bioprinting of tissues/organs where hydrogels play a critical role. Despite the outstanding developments in 3D engineered microstructures, current printer devices suffer from the risk of exposing loaded living agents to mechanical (nozzle-based) and thermal (nozzle-free) stresses. Thus, tuning the rheological, physical, and mechanical properties of hydrogels is a promising solution to address these issues. Th…
Chemical host detection and differential attraction in a parasitic pea crab infecting two echinoids
2011
Mechanisms of host detection and host choice are important for mobile parasites or symbionts that frequently move among host individuals. The parasitic pea crab Dissodactylus primitivus is an ectoparasite exploiting asymmetrically two spatangoid echinoid hosts, Meoma ventricosa and Plagiobrissus grandis. The entire life cycle takes place on M. ventricosa, while only adults colonize P. grandis, the host where female's fecundity is the greatest. Dissodactylus primitivus frequently exhibits host-switching, a behaviour that raises the question of host detection. To test if adult crabs are able to detect potential hosts and are attracted to the host where their fitness is greater, crab olfactory…
Artificial Biosystems by Printing Biology
2020
The continuous progress of printing technologies over the past 20 years has fueled the development of a plethora of applications in materials sciences, flexible electronics, and biotechnologies. More recently, printing methodologies have started up to explore the world of Artificial Biology, offering new paradigms in the direct assembly of Artificial Biosystems (small condensates, compartments, networks, tissues, and organs) by mimicking the result of the evolution of living systems and also by redesigning natural biological systems, taking inspiration from them. This recent progress is reported in terms of a new field here defined as Printing Biology, resulting from the intersection betwee…
Enhancing the sound absorption of small-scale 3D printed acoustic metamaterials based on Helmholtz resonators
2018
Acoustic metamaterials have recently become of interest for their ability to attenuate sound by breaking the mass-density law. In this paper, acoustic metamaterials based on Helmholtz resonators and capable of attenuating sound up to 30 dB are fabricated for sound absorption applications in the small scale. The proposed metamaterials are subwavelength at a factor of $\lambda /12$ with respect to the lateral dimension of the units. The directional response due to the position of the acoustic source on the sound attenuation provided by the metamaterial is investigated by controlling the location of a loudspeaker with a robot arm. To enhance and broaden the absorption bands, structural modific…
On the Heuristic Procedure to Determine Processing Parameters in Additive Manufacturing Based on Materials Extrusion
2020
We present a heuristic procedure for determining key processing parameters (PPs) in materials-extrusion-based additive manufacturing processes. The concept relies on a design-of-experiment approach and consists of eleven &ldquo