Journal articles on the topic '3d multilayer structures'
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1
Mensing, Glennys, Thomas Pearce, and David J. Beebe. "An Ultrarapid Method of Creating 3D Channels and Microstructures." JALA: Journal of the Association for Laboratory Automation 10, no. 1 (February 2005): 24–28. http://dx.doi.org/10.1016/j.jala.2004.11.006.
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We present a method of creating three dimensional microfluidic channel networks and freestanding microstructures using liquid phase photopolymerization techniques. The use of liquid phase microfabrication facilitates the creation of microstructured devices using low-cost materials and equipment. The ability to add multiple layers allows for complex geometries and increases the functional density of channeled devices. The multilayer technique provides a method of interconnecting layers or combining separate layers to form a truly integrated multilayered microfluidic device, as well as a means of forming multilayered freestanding structures. Because this method is based on the fundamentals of microfluidic tectonics (μFT), all components (valves, mixers, filters) compatible with μFT can be integrated into the multilayer channel networks.
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Wang, Zhipeng, Guoli Zhang, Youxin Zhu, Liqing Zhang, Xiaoping Shi, and Weiwei Wang. "Theoretical analysis of braiding strand trajectories and simulation of three-dimensional parametric geometrical models for multilayer interlock three-dimensional tubular braided preforms." Textile Research Journal 89, no. 19-20 (February 13, 2019): 4306–22. http://dx.doi.org/10.1177/0040517519826888.
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Multilayer interlock three-dimensional (3D) tubular braided composites have been widely used in propeller blades, high pressure pipelines, rocket nose cones and engine nozzles owing to prominent interlaminar shear properties, reliable damage tolerance and outstanding torsion performance. The prediction of the mechanical properties and the design of the fabric structures for the 3D braided composites are dependent on the trajectory distribution of strands and the geometrical model of the braided structure. This paper aims to build theoretical models for the braiding strand trajectories and presents a creative method to establish the parametric geometrical models for the multilayer interlock 3D tubular braided structures. Firstly, mathematical models of braiding strand trajectories are derived based on the analysis for the characteristics of carrier paths, the interlacing and interlocking of braided structures and the motion of braiding strands. The mathematical models are then developed to establish parametric expressions for multilayer interlock 3D tubular braided structures by the advanced development of UG NX®. In addition, the models of corresponding braiding strand trajectories and braiding structures can be obtained automatically in the simulation environment with the modification of design parameters. Finally, the established models are compared with the carbon fiber braided specimen. The results show that the innovative parametric geometric models of the multilayer interlock 3D tubular braided structures accurately describe the key characteristics of the preform.
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Recio-Sánchez, G., V. Torres-Costa, M. Manso-Silván, and R. J. Martín-Palma. "Nanostructured Porous Silicon Photonic Crystal for Applications in the Infrared." Journal of Nanotechnology 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/106170.
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In the last decades great interest has been devoted to photonic crystals aiming at the creation of novel devices which can control light propagation. In the present work, two-dimensional (2D) and three-dimensional (3D) devices based on nanostructured porous silicon have been fabricated. 2D devices consist of a square mesh of 2 μm wide porous silicon veins, leaving5×5 μm square air holes. 3D structures share the same design although multilayer porous silicon veins are used instead, providing an additional degree of modulation. These devices are fabricated from porous silicon single layers (for 2D structures) or multilayers (for 3D structures), opening air holes in them by means of 1 KeV argon ion bombardment through the appropriate copper grids. For 2D structures, a complete photonic band gap for TE polarization is found in the thermal infrared range. For 3D structures, there are no complete band gaps, although several new partial gaps do exist in different high-symmetry directions. The simulation results suggest that these structures are very promising candidates for the development of low-cost photonic devices for their use in the thermal infrared range.
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BRISCHETTO, SALVATORE. "AN EXACT 3D SOLUTION FOR FREE VIBRATIONS OF MULTILAYERED CROSS-PLY COMPOSITE AND SANDWICH PLATES AND SHELLS." International Journal of Applied Mechanics 06, no. 06 (December 2014): 1450076. http://dx.doi.org/10.1142/s1758825114500768.
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A 3D free vibration analysis of multilayered structures is proposed. An exact solution is developed for the differential equations of equilibrium written in general orthogonal curvilinear coordinates. The equations consider a geometry for shells without simplifications and allow the analysis of spherical shell panels, cylindrical shell panels, cylindrical closed shells and plates. The method is based on a layer-wise approach, the continuity of displacements and transverse shear/normal stresses is imposed at the interfaces between the layers of the structures. Results are given for multilayered composite and sandwich plates and shells. A free vibration analysis is proposed for a number of vibration modes, thickness ratios, imposed wave numbers, geometries and multilayer configurations embedding isotropic and orthotropic composite materials. These results can also be used as reference solutions for plate and shell 2D models developed for the analysis of multilayered structures.
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Partsch, Uwe, Adrian Goldberg, Martin Ihle, Gunter Hagen, and D. Arndt. "Novel Technology Options for Multilayer-Based Ceramic Microsystems." Journal of Microelectronics and Electronic Packaging 8, no. 3 (July 1, 2011): 95–101. http://dx.doi.org/10.4071/imaps.292.
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Ceramic multilayer technologies such as LTCC (low temperature cofired ceramics) or HTCC (high temperature cofired ceramics) are applied for the fabrication of highly integrated ceramic microelectronic packages. Furthermore, ceramic multilayer technologies offer the possibility of additionally integrating 3D structures for multilayer-based microsystems. This paper presents a new machine for tape/multilayer structuring that combines micro punching tools and micro UV-laser ablation/cutting. The application for the production of different multilayer-based components is described (e.g., LTCC-based PEM fuel cell system, LTCC-based pressure sensors). Aerosol jet printing is a new technology, for example, for rapid prototyping for LTCC multilayer and 3D deposition of functional layers on LTCC. Advantages and limitations of the technology are discussed.
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Wu, Guanzhao, Yangxue Liu, Zhen Yang, Nandakumar Katakam, Hossein Rouh, Sultan Ahmed, Daniel Unruh, Kazimierz Surowiec, and Guigen Li. "Multilayer 3D Chirality and Its Synthetic Assembly." Research 2019 (June 27, 2019): 1–11. http://dx.doi.org/10.34133/2019/6717104.
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3D chirality of sandwich type of organic molecules has been discovered. The key element of this chirality is characterized by three layers of structures that are arranged nearly in parallel fashion with one on top and one down from the center plane. Individual enantiomers of these molecules have been fully characterized by spectroscopies with their enantiomeric purity measured by chiral HPLC. The absolute configuration was unambiguously assigned by X-ray diffraction analysis. This is the first multilayer 3D chirality reported and is anticipated to lead to a new research area of asymmetric synthesis and catalysis and to have a broad impact on chemical, medicinal, and material sciences in future.
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Charfeddine, Mohamed Ali, Jean-Francis Bloch, and Patrice Mangin. "Mercury porosimetry and x-ray microtomography for 3-dimensional characterization of multilayered paper: Nanofibrillated cellulose, thermomechanical pulp, and a layered structure involving both." BioResources 14, no. 2 (February 13, 2019): 2642–50. http://dx.doi.org/10.15376/biores.14.2.2642-2650.
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Mercury intrusion porosimetry (MIP) is an inexpensive and common technique to characterize porous structures like paper. One major limitation of MIP is the lack of information about the arrangement of pores in the structure, information that is particularly relevant for multilayer structures such as thickness-structured paper. In this article, results from Synchrotron X-ray 3D microtomography are combined with MIP data to provide in-depth and improved information about the structures.
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Cheng, Hao, Taeuk Lim, Hyunjoon Yoo, Jie Hu, Seonwoo Kang, Sunghoon Kim, and Wonsuk Jung. "Fabrication of Three-Dimensional Multilayer Structures of Single-Walled Carbon Nanotubes Based on the Plasmonic Carbonization." Nanomaterials 11, no. 9 (August 27, 2021): 2213. http://dx.doi.org/10.3390/nano11092213.
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We developed a complex three-dimensional (3D) multilayer deposition method for the fabrication of single-walled carbon nanotubes (SWCNTs) using vacuum filtration and plasmonic carbonization without lithography and etching processes. Using this fabrication method, SWCNTs can be stacked to form complex 3D structures that have a large surface area relative to the unit volume compared to the single-plane structure of conventional SWCNTs. We characterized 3D multilayer SWCNT patterns using a surface optical profiler, Raman spectroscopy, sheet resistance, scanning electron microscopy, and contact angle measurements. Additionally, these carbon nanotube (CNT) patterns showed excellent mechanical stability even after elastic bending tests more than 1000 times at a radius of 2 mm.
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Leclercq, J. L., P. Rojo-Romeo, C. Seassal, J. Mouette, X. Letartre, and P. Viktorovitch. "3D structuring of multilayer suspended membranes including 2D photonic crystal structures." Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures 21, no. 6 (2003): 2903. http://dx.doi.org/10.1116/1.1627796.
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Deffenbaugh, Paul I., Mike Newton, and Kenneth H. Church. "Digital Manufacturing for Electrically Functional Satlet Structures." International Symposium on Microelectronics 2015, no. 1 (October 1, 2015): 000210–15. http://dx.doi.org/10.4071/isom-2015-wa15.
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3D printing structures is natural for the layer by layer approach. Using a single type of material and building complex structures is not optimized but it is mature. This digital approach to manufacturing has the advantages of lighter structures that maintain strength and can also address the emerging custom market. While these are important contributions, adding electrically functional characteristics to the structures will open new opportunities for next generation products. In the case of the presented materials, the target application is small satellite or Satlets. Adding electronics to 3D structures is not optimized or mature and therefore studying this will be important to understand the potential and the obstacles that must be addressed. Utilizing the combination of 3D printing and printed electronics, we printed a number of device demonstrations the show it is feasible to make diverse shapes with functional electronics. Demonstrations included 3D printed multilayer ceramic Ethernet harness, 3D printed plastic RF controlled impedance interconnect and USB harness and finally 3D printed connectors. Data will be presented on mechanical integrity of printed structures and electrical performance.
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Ihle, Martin, Uwe Partsch, Sindy Mosch, and Adrian Goldberg. "Aerosol Printing of High Resolution Films for LTCC-Multilayer Components." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (September 1, 2012): 000071–76. http://dx.doi.org/10.4071/cicmt-2012-ta25.
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For the electronic packaging of sensor stable and cost-efficient fine-line printing technologies on LTCC and high frequency laminates are needed. Especially common technologies like screen printing and thin film techniques are unsuitable for fine structures or too expensive. In addition there is no direct write technology for 3D-LTCC-designs as well as for high reliability Co-firing structures. Closing this gap the aerosol printing technology is used to print high resolution conductors on planar and non-planar substrates. Aerosol printing is a direct write non-contact printing technology of functional layers. After a pneumatic atomization the ink is transformed into 1 to 5 μm droplets. The resulting, continuous aerosol stream is focused by a sheath gas in the printing head. Thus the long standoff distance between substrate and deposition tip of max. 5 mm allows the 3D-printing on non-planar substrates. With optimized inks and printing parameters line widths of 10 μm are achievable. This paper will present applications for aerosol printed functional layers on LTCC. These are, for example, aerosol printed films embedded in co-fired LTCC, fine line structures for high frequency applications and the evaluation of printed 3D-structures like LTCC-stairways. Furthermore the 90 degree contacting of unconventional sensor designs will be presented.
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Ihle, Martin, Uwe Partsch, Sindy Mosch, and Adrian Goldberg. "Aerosol Printing of High Resolution Films for LTCC-Multilayer Components." Journal of Microelectronics and Electronic Packaging 9, no. 3 (July 1, 2012): 133–37. http://dx.doi.org/10.4071/imaps.340.
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For the electronic packaging of sensor stable and cost-efficient fine line printing technologies on LTCC and high frequency laminates are needed. Especially common technologies like screen printing and thin film techniques are unsuitable for fine structures or too expensive. In addition, there is no direct write technology for 3D LTCC designs as well as for high reliability cofiring structures. Closing this gap, aerosol printing technology is used to print high resolution conductors on planar and nonplanar substrates. Aerosol printing is a direct write noncontact printing technology of functional layers. After pneumatic atomization, the ink is transformed into 1–5 μm droplets. The resulting continuous aerosol stream is focused by a sheath gas in the printing head. Thus, the long standoff distance between the substrate and the deposition tip of max. 5 mm allows 3D printing on nonplanar substrates. With optimized inks and printing parameters, line widths of 10 μm are achievable. This paper will present applications for aerosol printed functional layers on LTCC. These are, for example, aerosol printed films embedded in cofired LTCC, fine line structures for high frequency applications, and the evaluation of printed 3D structures like LTCC stairways. Furthermore, the 90° contact of unconventional sensor designs will be presented.
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Jin, Lanming, Gaoming Jiang, Honglian Cong, and Chenguang Hou. "Geometrical Modelling of Jacquard Quilted Structures Weft Knitted Fabrics." Journal of Engineered Fibers and Fabrics 11, no. 1 (March 2016): 155892501601100. http://dx.doi.org/10.1177/155892501601100109.
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Jacquard quilted structure weft-knitted fabrics have many advantages, such as strong stereoscopic patterns, soft handling, adjustable apparel thickness, and use as home textiles. However, the final visual effects of such fabrics are difficult to predict prior to processing because of the rough surface caused by the connecting yarn and the inlay yarn of the fabric. This research applied a three-dimensional (3D) model instead of the original single-loop model to simulate knitted fabric. The 3D model is more suitable for a multilayer fabric because the simulation is quick, real, and convenient. The article includes experiments on structural parameters concerning regular dents of different samples, analysis of parameter data about the surface, and the simulation process with the objective of understanding the computer simulation of fabric. Results show good correlation between the simulation results and the actual fabric. Importantly, we can clearly see the expected effects in the fabrics without going through production and processing. This research will be useful for establishing a quick computer-generated simulation system for multilayer fabrics.
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Kung, Yu-Chun, Kuo-Wei Huang, Yu-Jui Fan, and Pei-Yu Chiou. "Fabrication of 3D high aspect ratio PDMS microfluidic networks with a hybrid stamp." Lab on a Chip 15, no. 8 (2015): 1861–68. http://dx.doi.org/10.1039/c4lc01211a.
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We report a novel methodology for fabricating large-area, multilayer, thin-film, high aspect ratio, 3D microfluidic structures with through-layer vias and open channels that can be bonded between hard substrates.
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Li, Zhen Xing, Akinori Yamanaka, and Masahiko Yoshino. "A New Process to Fabricate Three Dimensional Ordered Nano Dot Array Structures by Nano Plastic Forming and Dewetting." Key Engineering Materials 523-524 (November 2012): 627–32. http://dx.doi.org/10.4028/www.scientific.net/kem.523-524.627.
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Three dimensional (3D) nano/quantum dot array structures have attracted more and more attention due to their broad applications. A new fabrication method of multilayer ordered nano dot array with low cost and high throughput is developed in this paper. This process is combination of Top-down and Bottom-up approaches: Nano Plastic Forming (NPF) patterning of metal layer coated on the substrate as Top-down approach and self-organization by dewetting as Bottom-up approach. Effects of process conditions on 3D nano-dot array formation are studied experimentally. Regularity and uniformity of first layer nano-dot array is transferred to the second layer nano-dots by optimizing thickness of the spacer layer and Au coating layer. Multilayer ordered nano dot array structures with good alignment are obtained by repeating coating and annealing processes.
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Martens, R. L., D. J. Larson, T. F. Kelly, A. Cerezo, P. ’H Clifton, and N. Tabat. "Preparation of 3D Atom Probe Samples of Multilayered Film Structures using a Focused Ion Beam." Microscopy and Microanalysis 6, S2 (August 2000): 522–23. http://dx.doi.org/10.1017/s1431927600035108.
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Focused ion beam (FIB) instruments have become essential for the preparation of atom probe samples from heterogeneous materials. Previous sample preparation methods such as electropolishing are limited in their application due to either geometrical or electrochemical constraints. Recent developments in sample preparation using a FIB have enabled the production of AP samples from various materials and, more importantly, from non-traditional sample geometries that contain multilayered thin film structures (MLF).Most sample preparation using a FIB first involves a sample that has been reduced in size through some manual sample preparation technique like tripod polishing or cutting. Smaller, thinner samples require less milling time in the FIB. A silicon wafer etched with the “Bosch” process was used to produce a surface that contains millions of 20, 16, 12, 8, and 4 μm square by -180 μrn long “posts”, Fig. 1. A multilayer film structure is deposited on the flat surface of the silicon posts in a standard deposition process.
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NABET, BAHRAM, FRANCISCO CASTRO, AMRO ANWAR, and ADRIANO COLA. "HETERODIMENSIONAL CONTACTS AND OPTICAL DETECTORS." International Journal of High Speed Electronics and Systems 10, no. 01 (March 2000): 375–86. http://dx.doi.org/10.1142/s0129156400000386.
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The structures of systems of different dimensions and their interface can be called heterodimensional devices. In this paper we discuss a family of photodetector devices that are based on embedding three dimensional (3D) to two dimensional (2D) contacts by employing modulation doping of a layered heterostructure and contacting the resultant two dimensional electron gas by Schottky metal. The process of current transport between 3D and 2D is analyzed showing barrier enhancement mechanisms due to electron confinement. Optical spectral behavior is also discussed showing the effect of quantized energy levels as well as the electric field present in these multilayer structures.
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Azzolini, Claudio, Terenzio Congiu, Simone Donati, Alberto Passi, Petra Basso, Eliana Piantanida, Cesare Mariotti, et al. "Multilayer Microstructure of Idiopathic Epiretinal Macular Membranes." European Journal of Ophthalmology 27, no. 6 (May 19, 2017): 762–68. http://dx.doi.org/10.5301/ejo.5000982.
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Purpose To identify the ultramicroscopic structure of idiopathic epiretinal macular membranes (iEMMs) by scanning electron microscopy (SEM). Methods We examined 28 iEMMs surgically removed from 28 eyes of 28 patients. All specimens, previously observed at stereomicroscope, were treated with an osmium maceration technique. Fine resolution of iEMMs’ 3D architecture and their interaction with the retina were studied using a Philips SEM-FEG XL-30 microscope. Results The specimens appeared as laminar connective structures partially or completely adherent to the inner limiting membrane (ILM). We identified 4 types of structures: ( 1 ) distinct layers of thin sheets of woven fibers; ( 2 ) folded layers of inhomogeneous thickness of fibrous material more consistent; ( 3 ) thicker and more rigid layers recognizable as collagen fibrils with typical 64-nm period, collagen fibrils isolated or intermingled between them; ( 4 ) lacunar structures with inflammatory and/or necrotic material. The first 3 types of structures appear to thicken towards a centripetal direction from the ILM to the vitreous in order from 1 to 3. The interface of ILM-iEMM tissue shows particular small bridges of connection. Cells are rarely found, especially in the tissue near the ILM. Conclusions Layers of various materials follow one another in iEMMs. Cells are rarely found. The interface ILM-iEMM tissue shows particular small bridges of connection. The dynamic modeling of bended layers begins in soft tissue.
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Heunisch, Andreas, Ulrich Marzok, Marco Münchow, Ralf Müller, and Torsten Rabe. "In Situ Characterization of the Sintering Behavior of LTCC Laminates with Embedded Cavities by High Temperature Laser Profilometry." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2013, CICMT (September 1, 2013): 000275–82. http://dx.doi.org/10.4071/cicmt-tha44.
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Three-dimensionally structured LTCC multilayer with channels and inner cavities are required for numerous applications like microreactors, microfluidic systems or sensors. For the performance of such devices, the dimensional accuracy of the embedded structures is crucial. In the green state, the desired structures can be precisely implemented in the LTCC tapes by laser cutting, punching or milling. Unfortunately, during lamination and sintering, shape integrity of cavities and channels is notably affected by warpage and deformation. To investigate the sintering behavior of structured LTCC laminates, a newly developed High Temperature Laser Profilometer (HTLP) can be used. The HTLP allows 3D in-situ shape detection of flat ceramic samples and tapes all along the sintering process. It is applicable for temperatures up to 1000 °C and sample sizes up to 200 mm × 200 mm × 10 mm. During a measurement, the rotating sample is scanned spirally by a linearly moving laser distance sensor through a slot in the furnace top wall. Distance and position values deliver a 3D surface image of the sample. Current lateral dimensions, which are determined by sintering shrinkage, can be measured continuously. Local deformation and warpage can be visualized time- and temperature-resolved. This new method was used, to analyze the sintering behavior of LTCC multilayer laminates containing large size cavities. These were fabricated out of punched green sheets by low pressure lamination without inserts. Samples with cavities of varying cross sections, as well as cavities with and without connection to the surface were observed.
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He, Yan-Ping, Lv-Bing Yuan, and Jian Zhang. "Polycatenation tuned microporosity of two metal–tris(4′-carboxybiphenyl)amine frameworks with multilayer structures." Dalton Transactions 46, no. 39 (2017): 13352–55. http://dx.doi.org/10.1039/c7dt02976d.
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By employing a nanosized tris(4′-carboxybiphenyl)amine ligand to assemble with Zn2+ ions, a novel trilayer network (FIR-37) and an unprecedented 2D → 3D microporous polycatenation framework (FIR-38) based on unusual tetralayers have been synthesized and structurally characterized.
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Bilisik, Kadir, and Nesrin Sahbaz. "Structure-unit cell-based approach on three-dimensional representative braided preforms from four-step braiding: Experimental determination of effects of structure-process parameters on predetermined yarn path." Textile Research Journal 82, no. 3 (September 30, 2011): 220–41. http://dx.doi.org/10.1177/0040517511404597.
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The aim of this study was to understand the effects of braid pattern and the number of layers on three-dimensional (3D) braided unit cell structures. Various unit cell-based representative 3D braided preforms were developed. Data generated from these structures included unit cell dimensions, yarn angle, and yarn length in the unit cell structures. It was shown that braid patterns affected the 3D braided unit cell structures. The 1 × 1 braid pattern made fully interconnected integral 3D braided unit cell structures, whereas the 2 × 1 braid pattern created disconnected braid layers that were connected to the structures edges. When the number of layers increased, 3D braided unit cell thickness also increased. Braid pattern slightly affected the braider yarn angle, whereas the number of layers did not influence it. It was observed that the number of layers considerably affected the yarn length in the unit cell structure. Increasing the layer number from five to 10 layers created a yarn path in the unit cell edge regions called the ‘multilayer yarn length’. This yarn path was not observed below five-layer 3D braided unit cell structures. In jamming conditions, minimum jamming decreased the width of the unit cell structure, but maximum jamming increased its width. On the other hand, minimum jamming decreased the surface angle of the unit cell structure, whereas maximum jamming increased the surface angle. In addition, it was realized that jamming conditions influenced the density of the unit cell but did not affect the yarn length in the unit cell structures.
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Dehlinger, Dietrich, Benjamin Sullivan, Sadik Esener, Dalibor Hodko, Paul Swanson, and Michael J. Heller. "Automated Combinatorial Process for Nanofabrication of Structures Using Bioderivatized Nanoparticles." JALA: Journal of the Association for Laboratory Automation 12, no. 5 (October 2007): 267–76. http://dx.doi.org/10.1016/j.jala.2007.05.006.
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A fully automated electronic microarray control system (Nanochip 400 System) was used to carry out a combinatorial process to determine optimal conditions for fabricating higher order three-dimensional nanoparticle structures. Structures with up to 40 layers of bioderivatized nanoparticles were fabricated on a 400-test site CMOS microarray using the automated Nanochip 400 System. Reconfigurable electric fields produced on the surface of the CMOS microarray device actively transport, concentrate, and promote binding of 40 nm biotin- and streptavidin-derivatized nanoparticles to selected test sites on the microarray surface. The overall fabrication process including nanoparticle reagent delivery to the microarray device, electronic control of the CMOS microarray and the optical/fluorescent detection, and monitoring of nanoparticle layering are entirely controlled by the Nanochip 400 System. The automated nanoparticle layering process takes about 2 minutes per layer, with 10–20 seconds required for the electronic addressing and binding of nanoparticles, and roughly 60 seconds for washing. The addressing and building process is monitored by changes in fluorescence intensity as each nanoparticle layer is deposited. The final multilayered 3D structures are about 2 μm in thickness and 55 μm in diameter. Multilayer nanoparticle structures and control sites on the microarray were verified by SEM analysis.
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Bilisik, Kadir. "Three-dimensional axial braided preforms: experimental determination of effects of structure-process parameters on unit cell." Textile Research Journal 81, no. 20 (August 22, 2011): 2095–116. http://dx.doi.org/10.1177/0040517511414978.
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The aim of this study was to understand the effects of braid pattern and number of layers on 3D axial braided unit cell structures. Various unit cell based representative 3D axial braided preforms were developed. Data generated from these structures included unit cell dimensions, yarn angle and yarn length in the unit cell structures.It was shown that braid patterns affected the 3D axial braided unit cell structures. The 1 × 1 braid pattern made fully interconnected integral 3D axial braided unit cell structures, whereas the 2 × 1 braid pattern created disconnected braid layers which were connected to the structure edges. When the number of layers increased 3D axial braided unit cell thickness also increased. Braid pattern slightly affected the braided yarn angle. On the other hand, it was observed that the number of layers considerably affected the yarn length in the unit cell structure. Increasing the layer number from six to eight layers created a yarn path in the unit cell edge regions called the ‘multilayer yarn length’. This yarn path was not observed below eight layer 3D axial braided unit cell structures. In jamming conditions, minimum jamming decreased the width of the unit cell structure but maximum jamming increased its width. In addition, minimum jamming decreased the surface angle of the unit cell structure, conversely, however, the maximum jamming increased the surface angle. Also, it was realized that jamming conditions influenced the density of the unit cell but did not affect the yarn length in the unit cell structures.
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Ding, Da-Qiao, Atsushi Matsuda, Kasumi Okamasa, and Yasushi Hiraoka. "Linear elements are stable structures along the chromosome axis in fission yeast meiosis." Chromosoma 130, no. 2-3 (April 7, 2021): 149–62. http://dx.doi.org/10.1007/s00412-021-00757-w.
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AbstractThe structure of chromosomes dramatically changes upon entering meiosis to ensure the successful progression of meiosis-specific events. During this process, a multilayer proteinaceous structure called a synaptonemal complex (SC) is formed in many eukaryotes. However, in the fission yeast Schizosaccharomyces pombe, linear elements (LinEs), which are structures related to axial elements of the SC, form on the meiotic cohesin-based chromosome axis. The structure of LinEs has been observed using silver-stained electron micrographs or in immunofluorescence-stained spread nuclei. However, the fine structure of LinEs and their dynamics in intact living cells remain to be elucidated. In this study, we performed live cell imaging with wide-field fluorescence microscopy as well as 3D structured illumination microscopy (3D-SIM) of the core components of LinEs (Rec10, Rec25, Rec27, Mug20) and a linE-binding protein Hop1. We found that LinEs form along the chromosome axis and elongate during meiotic prophase. 3D-SIM microscopy revealed that Rec10 localized to meiotic chromosomes in the absence of other LinE proteins, but shaped into LinEs only in the presence of all three other components, the Rec25, Rec27, and Mug20. Elongation of LinEs was impaired in double-strand break-defective rec12− cells. The structure of LinEs persisted after treatment with 1,6-hexanediol and showed slow fluorescence recovery from photobleaching. These results indicate that LinEs are stable structures resembling axial elements of the SC.
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Naghshine, Babak B., and Amirkianoosh Kiani. "Laser processing of thin-film multilayer structures: comparison between a 3D thermal model and experimental results." Beilstein Journal of Nanotechnology 8 (August 24, 2017): 1749–59. http://dx.doi.org/10.3762/bjnano.8.176.
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In this research, a numerical model is introduced for simulation of laser processing of thin film multilayer structures, to predict the temperature and ablated area for a set of laser parameters including average power and repetition rate. Different thin-films on Si substrate were processed by nanosecond Nd:YAG laser pulses and the experimental and numerical results were compared to each other. The results show that applying a thin film on the surface can completely change the temperature field and vary the shape of the heat affected zone. The findings of this paper can have many potential applications including patterning the cell growth for biomedical applications and controlling the grain size in fabrication of polycrystalline silicon (poly-Si) thin-film transistors (TFTs).
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Zaraska, Krzysztof, Janina Gaudyn, Adam Bieńkowski, Marek Dohnalik, Andrzej Czerwiński, Mariusz Płuska, and Monika Machnik. "X-Ray Inspection of LTCC Devices." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, CICMT (September 1, 2011): 000215–23. http://dx.doi.org/10.4071/cicmt-2011-wp13.
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The appeal of LTCC (Low Temperature Cofired Ceramic) process lies in the possibility of creating multilayer (3D) structures, integrating conductor paths, passive elements, such as inductors and resistors and resonance cavities. Unfortunately, the very nature of cofired device makes post-firing optical inspection of buried elements impossible, as the ceramic material is opaque to visible light. This limitation, however, does not exist at X-ray wavelengths. The aim of this paper is to provide a practical overview of application of high resolution X-ray imaging for non-destructive inspection and fault detection in multilayer LTCC structures. First, we present a simplified mathematical description of X-ray absorption inside an LTCC structure and demonstrate that due to physical properties of substrate (glass/Al2O3 ceramic), conductor material (silver) and cavity fill (air), a high contrast image of the investigated structure can be obtained. Next, we show application of a commercial off-the shelf industrial X-ray system for imaging various faults in LTCC structures, such as: via voids (caused by inadequate filling of a via hole with conductor material), microcracks, paste creep (during lamination, excess via conductor leaks out of the via hole and in between the tape layers, shorting the via to an adjacent circuit), interruptions in conductor paths and alignment errors. We also demonstrate application of computed tomography for verifying 3D geometry of buried resonance cavities and detecting tape delaminations. Finally, we discuss limitations of the method, related to structure thickness (number of layers), material composition, imaging geometry and equipment characteristics, such as detector resolution and spatial noise.
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Umair, Muhammad, Syed Talha Ali Hamdani, Muhammad Ayub Asghar, Tanveer Hussain, Mehmet Karahan, Yasir Nawab, and Mumtaz Ali. "Study of influence of interlocking patterns on the mechanical performance of 3D multilayer woven composites." Journal of Reinforced Plastics and Composites 37, no. 7 (January 10, 2018): 429–40. http://dx.doi.org/10.1177/0731684417751059.
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Three-dimensional multilayer woven composites are mostly used in high-performance applications due to their excellent out-of-plane mechanical performance. The current research presents an experimental investigation on the mechanical behavior of three-dimensional orthogonal layer-to-layer interlock composites. The glass filament yarn and carbon tows were used as reinforcement in warp and weft directions respectively, whereas epoxy was used as a resin for composite fabrication. Three different types of orthogonal layer to layer interlock namely warp, weft, and bi-directional interlock composites were fabricated and the effect of interlocking pattern on their mechanical performance was evaluated. The evaluation of the mechanical performance was made on the basis of tensile strength, impact strength, flexural strength, and dynamic mechanical analysis of composites in warp and weft directions. It was found that warp and weft interlock composites showed better tensile behavior as compared to bi-directional interlock composite both in the warp and weft directions, due to the presence of less crimp as compared to the bi-directional interlock composite. However, the bi-directional interlock composite exhibited considerably superior impact strength and three-point bending strength as compared to the other structures under investigation. These superior properties of bi-directional interlock composites were achieved by interlocking points in warp and weft directions simultaneously, creating a more compact and isotropic structure. Tan delta values of dynamic mechanical analysis results showed that bi-directional interlock composite displayed the highest capacity of energy dissipation in the warp and weft directions while weft interlock structures displayed highest storage and loss moduli in the warp direction.
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Rupsa Roy, Swarup Sarkar,. "QCA based Novel Reversible Reconfigurable Ripple Carry Adder with Ripple Borrow Subtractor in Electro-Spin Technology." Psychology and Education Journal 58, no. 2 (February 10, 2021): 813–23. http://dx.doi.org/10.17762/pae.v58i2.1916.
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An important arithmetic component of “Arithmetic and Logic Unit” or ALU is reconfigured in this paper, known as “Full-Adder-Subtractor”, where an advance low-power, high-speed nano technology “QCA” with electro-spin criterion is used with reversibility and the advancement of multilayer 3D circuitry. In this modern digital world, this selected nano-sized technology is an effective alternative of widely used “CMOS Technology” because all the limitations, mainly limitation due to the presence of high power dissipation at the time of device-density increment in a “CMOS” based integrated circuit, can be optimized by “QCA” nano technology with electro-spin criterion and this technology also supports reversible logic in multilayer 3D platform with less complexity. This paper, primarily presents two novel “QCA” based 3-layered “Adder-Subtractor” designs using the collaboration of multilayer inverter gates, reversible modified 3-input Feynman-Gate and 3-input MG (Majority Gate) with very less cell-complexity, area-occupation, delay and energy-dissipation and high output-strength, temperature-tolerance and accuracy. A clear parametric investigation on presented designs are shown clearly in this paper through a comparative manner with some previous published related structures. Additionally, another parametric-experiment on a novel multibit reversible multilayer “QCA” based “Full-Adder-Subtractor” circuitry using the working phenomenon of “Ripple Carry Adder” (RCA) and multibit subtractor (“ripple borrow subtractor” or RBS) is presented in this proposed work in a proper way and this combination of RCA and multibit subtraction operation converts the proposed circuitry into a hybrid form, which is more effective compare to some other advanced adders in parametric-optimization field.
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Müller, Dominik, Jonas Graetz, Andreas Balles, Simon Stier, Randolf Hanke, and Christian Fella. "Laboratory-Based Nano-Computed Tomography and Examples of Its Application in the Field of Materials Research." Crystals 11, no. 6 (June 12, 2021): 677. http://dx.doi.org/10.3390/cryst11060677.
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In a comprehensive study, we demonstrate the performance and typical application scenarios for laboratory-based nano-computed tomography in materials research on various samples. Specifically, we focus on a projection magnification system with a nano focus source. The imaging resolution is quantified with common 2D test structures and validated in 3D applications by means of the Fourier Shell Correlation. As representative application examples from nowadays material research, we show metallization processes in multilayer integrated circuits, aging in lithium battery electrodes, and volumetric of metallic sub-micrometer fillers of composites. Thus, the laboratory system provides the unique possibility to image non-destructively structures in the range of 170–190 nanometers, even for high-density materials.
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Zaraska, Krzysztof, Janina Gaudyn, Adam Bienńkowski, Marek Dohnalik, Andrzej Czerwiński, Mariusz Płuska, Monika Machnik, and Katarzyna Wójcik. "X-Ray Inspection of LTCC Devices: Theory and Practice." Journal of Microelectronics and Electronic Packaging 8, no. 2 (April 1, 2011): 49–57. http://dx.doi.org/10.4071/imaps.289.
Full textAbstract:
The appeal of the LTCC (low temperature cofired ceramic) process lies in the possibility of creating multilayer (3D) structures, integrating conductor paths between passive elements, such as inductors, resistors, and resonance cavities. Unfortunately, the very nature of a cofired device makes postfiring optical inspection of buried elements impossible, as the ceramic material is opaque to visible light. This limitation, however, does not exist at x-ray wavelengths. The aim of this paper is to provide a practical overview of the application of high resolution x-ray imaging for nondestructive inspection and fault detection in multilayer LTCC structures. First, we present a simplified mathematical description of x-ray absorption inside an LTCC structure and demonstrate that due to the physical properties of the substrate (glass/Al2O3 ceramic), the conductor material (silver), and the cavity fill (air), a high contrast image of the investigated structure can be obtained. Next, we show the application of a commercial off the shelf industrial x-ray system for imaging various faults in LTCC structures, such as via voids (caused by inadequate filling of a via hole with conductor material), microcracks, paste creep (during lamination, excess via conductor leaks out of the via hole and in between the tape layers, shorting the via to an adjacent circuit), interruptions in conductor paths, and alignment errors. We also demonstrate the application of computed tomography to verify 3D geometry of buried resonance cavities and detect tape delaminations. Finally, we discuss the limitations of the method, related to structure thickness (number of layers), material composition, imaging geometry, and equipment characteristics, such as detector resolution and spatial noise.
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Baitab, Danish Mahmood, Dayang Laila Abdul Majid, Ermira Junita Abdullah, and Mohd Faisal Abdul Hamid. "Improving the stiffness of multilayer 3D woven composites by the integration of shape memory alloys (SMAs) into structures." Journal of The Textile Institute 111, no. 9 (December 3, 2019): 1371–79. http://dx.doi.org/10.1080/00405000.2019.1696129.
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Chen, Xiaojun, Deyun Mo, and Manfeng Gong. "A Flexible Method for Nanofiber-based 3D Microfluidic Device Fabrication for Water Quality Monitoring." Micromachines 11, no. 3 (March 6, 2020): 276. http://dx.doi.org/10.3390/mi11030276.
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Water pollution seriously affects human health. Accurate and rapid detection and timely treatment of toxic substances in water are urgently needed. A stacked multilayer electrostatic printing technique was developed for making nanofiber-based microfluidic chips for water-quality testing. Nanofiber membrane matrix structures for microfluidic devices were fabricated by electrospinning. A hydrophobic barrier was then printed through electrostatic wax printing. This process was repeatedly performed to create three-dimensional nanofiber-based microfluidic analysis devices (3D-µNMADs). Flexible printing enabled one-step fabrication without the need for additional alignment or adhesive bonding. Practical applications of 3D-µNMADs include a colorimetric platform to quantitatively detect iron ion concentrations in water. There is also great potential for personalized point-of-care testing. Overall, the devices offer simple fabrication processes, flexible prototyping, potential for mass production, and multi-material integration.
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Vyslouzilova, Lucie, Martin Seidl, Jakub Hruza, Jiri Bobek, David Lukas, and Petr Lenfeld. "Nanofibrous Filters for Respirators." Advanced Materials Research 1119 (July 2015): 126–31. http://dx.doi.org/10.4028/www.scientific.net/amr.1119.126.
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This article deals with a development of new filtration materials for respirators. Contemporary used filters with charged microfibers are not sufficiently stable in all conditions and not efficient for all types of particles and that is the reason why the requirement for new generation of filtration materials is rising up. The research was focused on the development of nanofibrous filters that have a great precondition to be used as filters for respirators. The filtering material was designed as a multilayer sandwich consisting of spundbound, meltblown and nanofibrous layers. For the evaluation of final properties and filtering performances different 3D structures were also created.
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Yan, Zheng, Fan Zhang, Fei Liu, Mengdi Han, Dapeng Ou, Yuhao Liu, Qing Lin, et al. "Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials." Science Advances 2, no. 9 (September 2016): e1601014. http://dx.doi.org/10.1126/sciadv.1601014.
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Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the original versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. A 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality (Q) factors and broader working angles compared to those of conventional 2D counterparts.
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Khoshk Rish, Salman, Arash Tahmasebi, Rou Wang, Jinxiao Dou, and Jianglong Yu. "Novel composite nano-materials with 3D multilayer-graphene structures from biomass-based activated-carbon for ultrahigh Li-ion battery performance." Electrochimica Acta 390 (September 2021): 138839. http://dx.doi.org/10.1016/j.electacta.2021.138839.
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Hübner, Matthias, Monireh Fazeli, Thomas Gereke, and Chokri Cherif. "Geometrical design and forming analysis of three-dimensional woven node structures." Textile Research Journal 88, no. 2 (November 13, 2016): 213–24. http://dx.doi.org/10.1177/0040517516677231.
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Structural frames have been established in many technical applications and typically consist of interconnected profiles. The profiles are commonly joined with node elements. For lightweight structures, the use of composite node elements is expedient. Due to the anisotropic mechanical properties of the fibers, high demands are placed on the orientation of the fibers in the textile reinforcement structure. A continuous fiber course around the circumference and at the junctions is necessary for an excellent force transmission. A special binding and forming process was developed based on the weaving technology. It allows the production of near-net-shaped node elements with branches in any spatial direction, which meet the requirements of load-adjusted fiber orientation. The principles by which these three-dimensional (3D) node elements are converted into a suitable geometry for weaving as a net shape multilayer fabric are reported. The intersections of the branches are described mathematically and flattened to a plane. This is the basis for the weave pattern development. Forming simulations on the macro- and meso-scales complement the analyses. A macro-scale model based on the finite element method (FEM) is used to verify the general formability and the accuracy of the flattenings. Since yarns are pulled through the textile structure in the novel forming process, the required tensile forces and the pulling lengths of the individual yarns are analyzed with a meso-scale FEM model. The flattening for two different node structures is realized successfully, and the simulation proves formability. Furthermore, the necessary forming forces are determined. Finally, the developed method for flattening the 3D geometry is suitable for the design of a variety of spatial node structures and the simulation supports the design of automated forming processes.
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Hagen, Gunter, Thomas Kopp, Steffen Ziesche, Uwe Partsch, and Ester Ruprecht. "Combined 3D Micro Structuring of Ceramic Green Tape Using Punching, Embossing and Laser Processing." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (September 1, 2012): 000341–47. http://dx.doi.org/10.4071/cicmt-2012-wa34.
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Multilayer ceramics technology, as LTCC, offers several advantages for the fabrication of miniaturized three-dimensional structures, e.g. for microsystem applications, where electrical, mechanical and fluidic functions can be combined in robust and compact packages. 3D features, required by those applications, are e.g. vias for electrical and thermal interconnection, cavities for chip integration and channels for fluidic functions. They can be realized, in principle, in the sintered, as well as in the green state, but structuring in the green state dominates due to the then far better machinability of the material. Ceramic green tape structuring is usually accomplished by mechanical or laser machining. Punching is the standard process for realizing vias or cavities in LTCC. By nature, only through tape features can be realized, but 3D features can be realized by stacking of several layers. Embossing can be used for the realization of quite complex 3D structures with high resolution. It can be carried out either at elevated temperature, at which the binder of the tape is softened (hot embossing) or at room temperature (cold embossing). Laser structuring is a quite flexible method, which allows both through-cutting and engraving without any specific tool. However, a certain roughness of ablated areas cannot be avoided, and depth control and uniformity of laser engraved features remain challenging. In the present paper, the different techniques will be compared regarding their appropriateness for different structuring tasks. A combined use of punching, embossing and laser processing is described, which has been made possible by a novel machine and tool concept.
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Wu, Guanzhao, Yangxue Liu, Zhen Yang, Liulei Ma, Yao Tang, Xianliang Zhao, Hossein Rouh, et al. "Triple-Columned and Multiple-Layered 3D Polymers: Design, Synthesis, Aggregation-Induced Emission (AIE), and Computational Study." Research 2021 (February 8, 2021): 1–13. http://dx.doi.org/10.34133/2021/3565791.
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Conjugated polymers and oligomers have great potentials in various fields, especially in materials and biological sciences because of their intriguing electronic and optoelectronic properties. In recent years, the through-space conjugation system has emerged as a new assembled pattern of multidimensional polymers. Here, a novel series of structurally condensed multicolumn/multilayer 3D polymers and oligomers have been designed and synthesized through one-pot Suzuki polycondensation (SPC). The intramolecularly stacked arrangement of polymers can be supported by either X-ray structural analysis or computational analysis. In all cases, polymers were obtained with modest to good yields, as determined by GPC and 1H-NMR. MALDI-TOF analysis has proven the speculation of the step-growth process of this polymerization. The computational study of ab initio and DFT calculations based on trimer and pentamer models gives details of the structures and the electronic transition. Experimental results of optical and AIE research confirmed by calculation indicates that the present work would facilitate the research and applications in materials.
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Shao, Changmin, Yuxiao Liu, Junjie Chi, Jie Wang, Ze Zhao, and Yuanjin Zhao. "Responsive Inverse Opal Scaffolds with Biomimetic Enrichment Capability for Cell Culture." Research 2019 (October 29, 2019): 1–10. http://dx.doi.org/10.34133/2019/9783793.
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Three-dimensional (3D) porous scaffolds have a demonstrated value for tissue engineering and regenerative medicine. Inspired by the predation processes of marine predators in nature, we present new photocontrolled shrinkable inverse opal graphene oxide (GO) hydrogel scaffolds for cell enrichment and 3D culture. The scaffolds with adjustable pore sizes and morphologies were created using a GO and N-isopropylacrylamide dispersed solution as a continuous phase of microfluidic emulsions for polymerizing and replicating. Because of the interconnected porous structures and the remotely controllable volume responsiveness of the scaffolds, the suspended cells could be enriched into the inner spaces of the scaffolds through predator-like swallowing and discharging processes. Hepatocyte cells concentrated in the scaffold pores could form denser 3D spheroids more quickly via the controlled compression force caused by the shrinking of the dynamic scaffolds. More importantly, with a program of scaffold enrichment with different cells, an unprecedented 3D multilayer coculture system of endothelial-cell-encapsulated hepatocytes and fibroblasts could be generated for applications such as liver-on-a-chip and bioartificial liver. It was demonstrated that the resultant multicellular system offered significant improvements in hepatic functions, such as albumin secretion, urea synthesis, and cytochrome P450 expression. These features of our scaffolds make them highly promising for the biomimetic construction of various physiological and pathophysiological 3D tissue models, which could be used for understanding tissue level biology and in vitro drug testing applications.
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Alidoost, F., and H. Arefi. "KNOWLEDGE BASED 3D BUILDING MODEL RECOGNITION USING CONVOLUTIONAL NEURAL NETWORKS FROM LIDAR AND AERIAL IMAGERIES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (June 10, 2016): 833–40. http://dx.doi.org/10.5194/isprsarchives-xli-b3-833-2016.
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In recent years, with the development of the high resolution data acquisition technologies, many different approaches and algorithms have been presented to extract the accurate and timely updated 3D models of buildings as a key element of city structures for numerous applications in urban mapping. In this paper, a novel and model-based approach is proposed for automatic recognition of buildings’ roof models such as flat, gable, hip, and pyramid hip roof models based on deep structures for hierarchical learning of features that are extracted from both LiDAR and aerial ortho-photos. The main steps of this approach include building segmentation, feature extraction and learning, and finally building roof labeling in a supervised pre-trained Convolutional Neural Network (CNN) framework to have an automatic recognition system for various types of buildings over an urban area. In this framework, the height information provides invariant geometric features for convolutional neural network to localize the boundary of each individual roofs. CNN is a kind of feed-forward neural network with the multilayer perceptron concept which consists of a number of convolutional and subsampling layers in an adaptable structure and it is widely used in pattern recognition and object detection application. Since the training dataset is a small library of labeled models for different shapes of roofs, the computation time of learning can be decreased significantly using the pre-trained models. The experimental results highlight the effectiveness of the deep learning approach to detect and extract the pattern of buildings’ roofs automatically considering the complementary nature of height and RGB information.
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Alidoost, F., and H. Arefi. "KNOWLEDGE BASED 3D BUILDING MODEL RECOGNITION USING CONVOLUTIONAL NEURAL NETWORKS FROM LIDAR AND AERIAL IMAGERIES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (June 10, 2016): 833–40. http://dx.doi.org/10.5194/isprs-archives-xli-b3-833-2016.
Full textAbstract:
In recent years, with the development of the high resolution data acquisition technologies, many different approaches and algorithms have been presented to extract the accurate and timely updated 3D models of buildings as a key element of city structures for numerous applications in urban mapping. In this paper, a novel and model-based approach is proposed for automatic recognition of buildings’ roof models such as flat, gable, hip, and pyramid hip roof models based on deep structures for hierarchical learning of features that are extracted from both LiDAR and aerial ortho-photos. The main steps of this approach include building segmentation, feature extraction and learning, and finally building roof labeling in a supervised pre-trained Convolutional Neural Network (CNN) framework to have an automatic recognition system for various types of buildings over an urban area. In this framework, the height information provides invariant geometric features for convolutional neural network to localize the boundary of each individual roofs. CNN is a kind of feed-forward neural network with the multilayer perceptron concept which consists of a number of convolutional and subsampling layers in an adaptable structure and it is widely used in pattern recognition and object detection application. Since the training dataset is a small library of labeled models for different shapes of roofs, the computation time of learning can be decreased significantly using the pre-trained models. The experimental results highlight the effectiveness of the deep learning approach to detect and extract the pattern of buildings’ roofs automatically considering the complementary nature of height and RGB information.
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Alaluss, Khaled, and Peter Mayr. "Additive Manufacturing of Complex Components through 3D Plasma Metal Deposition—A Simulative Approach." Metals 9, no. 5 (May 17, 2019): 574. http://dx.doi.org/10.3390/met9050574.
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This study examines simulative experimental investigations on the additive manufacturing of complex component geometries using 3D plasma metal deposition (3DPMD). Here, complex contour surfaces for a cross-rolling tool were produced from weld metals in multilayer technology through 3DPMD. As a consequence of the special features of 3DPMD with large-weld metal volumes, greatly differing properties between base material/deposited material and asymmetrical heat input, the resulting shrinkage, deformation and residual stresses are particularly critical. These lead to dimensional and form deviations as well as the formation of cracks, which has a negative influence on the quality of the plasma deposition-welded component structures. By means of the thermo-elastic-plastic simulation model, the temperature field distribution, deformation, and residual stresses occurring during additive 3DPMD of tool contours were predicted and analyzed. The temperature field distribution and its gradients were determined using the ellipsoid heat-source model for the 3DPMD process. On this basis, a coupled thermo-elastic-plastic structural–mechanical analysis was performed. Accordingly, the results achieved were used for the production of almost-net-shaped tool contour surfaces with predefined layer properties. The acquired simulation results of the temperature fields, deformation, and residual stress condition show good alignment with the experimental results.
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Bogomol’nyi, V. M. "Electroelasticity Relations and Fracture Mechanics of Piezoelectric Structures." Applied Mechanics Reviews 60, no. 1 (January 1, 2007): 21–36. http://dx.doi.org/10.1115/1.2375142.
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Three-dimensional (3D) constitutive equations of piezoelectric (PZ) plates and shells are considered for inverse linear and electrostrictive (quadratic) piezoeffects. Prestressed multilayer PZ shells reinforced with metal including the case of uneven thickness polarization are studied. Asymptotic and variational methods to solve the governing differential equations of PZ shells are considered. Concentrations of electrical and mechanical fields near structure imperfections and external local loading are investigated. The electrothermoviscoelastic heating of PZ shells is considered at harmonic excitation. From numerical analysis and the experimental data of energy dissipation and the temperature behavior of PZ shell the conditions of optimal transformation of electric energy into mechanical deformations are defined. Thus, the geometrical parameters and working frequencies are determined with due account of dielectric relaxation processes. The following nonlinear phenomena are studied: acoustoelectronic wave amplification; electron injection into metalized polar dielectric; resonance growth by 5–20 times of internal electrical field strength in the PZ shells and plates; and autothermostabilization of ferroelectric resonators. For a better understanding of R.D. Mindlin’s gradient theory of polarization in view of electron processes in thin metal-dielectric-metal structures, use was made of solid state physics interpretations as well as experimental data. High concentration of mechanical stresses and temperature and electrical fields near structure defects (first of all, near boundary between various materials) defines the main properties of polar dielectrics. An unknown domain of electrode rough surface influence was estimated, and as result an uneven polarization distribution was found. A theory of nonlinear autowave systems with energy dissipation was used in a physical model of the electrothermal fracture of dielectrics (contacting with metal electrodes), and as a result a nondestructive testing method to study the microstructure defect formation has been suggested.
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Stier, Simon P., and Holger Böse. "Ablative Laser Structuring for Stretchable Multilayer and Multi-Material Electronics and Sensor Systems." Proceedings 56, no. 1 (December 17, 2020): 21. http://dx.doi.org/10.3390/proceedings2020056021.
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Conventional machining and shaping processes for polymers and elastomers such as injection molding exhibit significant disadvantages, as specific tools have to be manufactured, the method of machining is highly dependent on the material properties, and the cost of automation is usually high. Therefore, additive manufacturing processes (3D printing) have established themselves as an alternative. This eliminates the expensive production of tools and the production is individualized. However, the specific (additive) manufacturing process remains highly dependent on the properties of the material. These processes include selective laser sintering (SLS) for powdered thermoplastic polymers and metals, extrusion such as fused deposition modeling (FDM) for thermoplastic polymers in wire form, or optical curing such as digital light processing (DLP) for liquid resins. Especially for elastomer sensors or circuit boards (structure of several alternately constituted approx. 100 µm-thick elastomer films made with different types of liquid silicone rubber), there is no suitable additive manufacturing process that combines liquid, partly non-transparent source materials, multi-component printing, and very fine layer thicknesses. In order to enable a largely automated, computer-aided manufacturing process, we have developed the concept of ablative multilayer and multi-material laser-assisted manufacturing. Here, the layers (conductive and non-conductive elastomers, as well as metal layers for contacting) are first coated over the entire surface (e.g., spray, dip, or doctor blade coating, as well as galvanic coating) and then selectively removed with a CO2 or fiber laser. These steps are repeated several times to achieve a multi-layer structured design. Is it not only possible to adjust and improve the work previously carried out manually, but also to introduce completely new concepts, such as fine through-plating between the layers to enable much more compact structures to be possible. As an exemplary application, we have used the process for manufacturing a thin and surface solderable pressure sensor and a stretchable circuit board.
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Yang, Xiaojiang, Xiaotao Wen, Dongyong Zhou, Yahui Wang, Zhenghe Yan, and Xiao Li. "Reconstruction of distorted structures in the fault shadow zone based on the fully connected network." Interpretation 9, no. 4 (September 7, 2021): T1089—T1100. http://dx.doi.org/10.1190/int-2020-0233.1.
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Lateral changes in velocity about faults can give rise to fault shadow (FS) zones on time-migrated data volumes, which can result in structural interpretation artifacts in the fault trap reservoir. To address this issue, we have adopted a new reconstruction method of FS distortion structures based on a deep learning fully connected network (FCN). We use the 3D stratigraphic dip attributes to quantitatively delineate the extent of the FS zone. Then, we train a model to construct a nonlinear trend surface based on the structures of the stratigraphic reflectors that fall outside of the shadow zone. Finally, we use this nonlinear trend surface to compensate for the distorted structure within the FS zone. We calibrate our method using synthetic data and find that the method can accurately recover structural data within the FS distortion zone. We then test the effectiveness of our workflow by applying it to recover real FS distortion structures in the Pearl River Mouth Basin of the South China Sea. The results confirm that our method significantly reduces drilling depth errors in the FS zone. Compared to the traditional polynomial fitting method, the multilayer, multiparameter, and flexible nonlinear activation function of FCN is more capable of reconstructing nonlinear geologic structures in the FS zone. We find the FCN-based geologic reconstruction method to be efficient and effective for exploring potential structures in the FS zone and thereby in avoiding the risks of structural failure.
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Isapour, A., D. Bahloul, and A. B. Kouki. "A comparative study on four different transmission lines in LTCC for 60 GHz applications." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2016, CICMT (May 1, 2016): 000191–98. http://dx.doi.org/10.4071/2016cicmt-tha22.
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Abstract The wireless telecommunication systems have an undeniable role in today's society. The rapid progress of wireless services and applications accelerates demands for high data-rate reliable systems. The 60 GHz band with its 5 GHz globally unlicensed available spectrum, provides a great opportunity for the next generation of high data-rate wireless communication. Despite this attractive bandwidth surrounding 60 GHz, there are still many challenges to be addressed such as the loss performance and the integration with other systems. Low Temperature Cofired Ceramic (LTCC) technology, with its unique and mature multilayer fabrication process, has excellent capability of realizing miniaturized 3D low loss structures to overcome these challenges. Since, one of the key components in any communication system for both interconnecting and designing components is Low loss transmission lines, in this article we overview the performances and challenges for four different most practical transmission lines at 60 GHz in LTCC: Microstrip, Stripline, Coplanar Waveguide (CPW), and LTCC Integrated Waveguide (LIW).
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Radovanović, J., V. Milanović, Z. Ikonić, and D. Indjin. "Optimization of Semimagnetic Semiconductor-Based Nanostructures for Spintronic Applications." Materials Science Forum 518 (July 2006): 35–40. http://dx.doi.org/10.4028/www.scientific.net/msf.518.35.
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We have analyzed the spin-filtering effects of the electron current in asymmetric ZnSe/Zn1-xMnxSe multilayer structures, under the influence of both an external magnetic field and a bias voltage. In this type of semiconductor systems, conduction band electrons interact with 3d electrons of the magnetic Mn2+ ions. Because of this sp-d exchange interaction, an external magnetic field modulates the effective potential profile seen by spin-up and spin-down electrons, giving rise to a large Zeeman effect. It is found that the degree of spin polarization changes significantly when the electrical bias is switched from forward to reverse, thus the proposed structure displays obvious behavior of spin-filter diode. This originates from the effective “lifting” of the potential for spin-up electrons, which tunnel through actual potential barriers. Structural parameters optimization, with the goal of maximizing the spin-filtering coefficient, was performed by using simulated annealing algorithm. The described effect may be important for designing new tunable spin-based multifunctional semiconductor devices.
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Ouassal, Hassna, Jafar Shaker, Langis Roy, Khelifa Hettak, and Reza Chaharmir. "Line Defect-Layered EBG Waveguides in Dielectric Substrates." International Journal of Antennas and Propagation 2018 (June 4, 2018): 1–9. http://dx.doi.org/10.1155/2018/3469730.
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A dielectric-based multilayer structure composed of U-shaped rings (ML-UR) is used to develop a class of novel electromagnetic band gap (EBG) slab waveguide. The structure has two band gaps that narrow down as dielectric constant is increased. The EBG slab waveguide is created by embedding a single-layer line defect inside the 3D crystal of the EBG slab guide. Unlike our previously published foam-based EBG structure, the use of dielectric spacer in the EBG waveguides offers significant advantages in terms of overall size, structure reliability, and design flexibility. The waveguide structures reported in this paper are designed to operate at X-band (8–12 GHz) while being fed by coplanar-slotline transitions. Prototypes were fabricated and characterized experimentally. The insertion loss decreases by decreasing the number of full lattices of ML-UR surrounding the channels. The proposed waveguide has potential in microwave components such as directional couplers, phase shifters, and antenna array feeding networks.
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Nasreen, Adeela, Muhammad Umair, Khubab Shaker, Syed Talha Ali Hamdani, and Yasir Nawab. "Development and characterization of three-dimensional woven fabric for ultra violet protection." International Journal of Clothing Science and Technology 30, no. 4 (August 6, 2018): 536–47. http://dx.doi.org/10.1108/ijcst-02-2018-0013.
Full textAbstract:
Purpose The purpose of this paper is to investigate the effect of materials, three dimensional (3D) structure and number of fabric layers on ultraviolet protection factor (UPF), air permeability and thickness of fabrics. Design/methodology/approach Total 24 fabrics samples were developed using two 3D structures and two weft materials. In warp direction cotton (CT) yarn and in weft direction polypropylene (PP) and polyester (PET) were used. Air permeability, thickness and UPF testings were performed and relationship among fabric layers, air permeability, thickness and UPF was developed. Findings UPF and thickness of fabrics increases with number of fabric layers, whereas air permeability decreases with the increase in number of fabric layers. Furthermore, change of multilayer structure from angle interlock to orthogonal interlock having same base weave does not give significant effect on UPF. However, change of material from polyester (PET) to polypropylene (PP) has a dominant effect on UPF. Minimum of three layers of cotton/polyester fabric, without any aid of ultraviolet radiation (UV) resistant coating, are required to achieve good. Cotton/polyester fabrics are more appropriate for outdoor application due to their long-term resistance with sunlight exposure. Originality/value Long-term exposure to UV is detrimental. So, there is need of proper selection of material and fabric to achieve ultraviolet protection. 3D fabrics have yarns in X, Y as well as in Z directions which provide better ultraviolet protection as compared to two dimensional (2D) fabrics. In literature, mostly work was done on ultraviolet protection of 2D fabrics and surface coating of fabrics. There is limited work found on UPF of 3D woven fabrics.
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Jao, Ruei-Fu, and Ming-Chieh Lin. "Quantitative Analysis of Photon Density of States for One-Dimensional Photonic Crystals in a Rectangular Waveguide." Crystals 9, no. 11 (November 4, 2019): 576. http://dx.doi.org/10.3390/cryst9110576.
Full textAbstract:
Light propagation in one-dimensional (1D) photonic crystals (PCs) enclosed in a rectangular waveguide is investigated in order to achieve a complete photonic band gap (PBG) while avoiding the difficulty in fabricating 3D PCs. This work complements our two previous articles (Phys. Rev. E) that quantitatively analyzed omnidirectional light propagation in 1D and 2D PCs, respectively, both showing that a complete PBG cannot exist if an evanescent wave propagation is involved. Here, we present a quantitative analysis of the transmission functions, the band structures, and the photon density of states (PDOS) for both the transverse electric (TE) and transverse magnetic (TM) polarization modes of the periodic multilayer heterostructure confined in a rectangular waveguide. The PDOS of the quasi-1D photonic crystal for both the TE and TM modes are obtained, respectively. It is demonstrated that a “complete PBG” can be obtained for some frequency ranges and categorized into three types: (1) below the cutoff frequency of the fundamental TE mode, (2) within the PBG of the fundamental TE mode but below the cutoff frequency of the next higher order mode, and (3) within an overlap of the PBGs of either TE modes, TM modes, or both. These results are of general importance and relevance to the dipole radiation or spontaneous emission by an atom in quasi-1D periodic structures and may have applications in future photonic quantum technologies.