The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Jianghui Zheng - One of the best experts on this subject based on the ideXlab platform.
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spin coating free Fabrication for highly efficient perovskite solar cells
Solar Energy Materials and Solar Cells, 2017Co-Authors: Jianghui Zheng, Xiaofan Deng, Shujuan Huang, Martin A Green, Chao Chen, Meng Zhang, Anita HobaillieAbstract:A spin-coating-free Fabrication Sequence has been developed for the Fabrication of highly efficient organic-inorganic halide perovskite solar cells (PSCs). A novel blow-drying method is demonstrated to be successful in depositing high quality mesoporous TiO2 (mp-TiO2), methylammonium lead halide (CH3NH3PbI3) perovskite and spiro-MeOTAD layers. When combined with compact TiO2 (c-TiO2) deposited by spray pyrolysis which is also a spin-coating-free process, a stabilized power conversion efficiency exceeding 17% can be achieved for the glass/FTO/c-TiO2/mp-TiO2/ CH3NH3PbI3/spiro-MeOTAD/Au device. This is the highest efficiency for PSCs fabricated without the use of spin-coating to our knowledge. This method provides a pathway towards a scalable process for fabricating high-performance, large area and reproducible PSCs.
Wu J. - One of the best experts on this subject based on the ideXlab platform.
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Space-time topology optimization for additive manufacturing: Concurrent optimization of structural layout and Fabrication Sequence
'Springer Science and Business Media LLC', 2019Co-Authors: Wang W., Munro D.p., Wang C.c., Van Keulen A., Wu J.Abstract:The design of optimal structures and the planning of (additive manufacturing) Fabrication Sequences have been considered typically as two separate tasks that are performed consecutively. In the light of recent advances in robot-assisted (wire-arc) additive manufacturing which enable addition of material along curved surfaces, we present a novel topology optimization formulation which concurrently optimizes the structure and the Fabrication Sequence. For this, two sets of design variables, i.e., a density field for defining the structural layout, and a time field which determines the Fabrication process order, are simultaneously optimized. These two fields allow to generate a Sequence of intermediate structures, upon which manufacturing constraints (e.g., Fabrication continuity and speed) are imposed. The proposed space-time formulation is general, and is demonstrated on three Fabrication settings, considering self-weight of the intermediate structures, process-dependent critical loads, and time-dependent material properties.Materials and ManufacturingStructural Optimization and Mechanic
A. Van Keulen - One of the best experts on this subject based on the ideXlab platform.
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Space-time topology optimization for additive manufacturing : Concurrent optimization of structural layout and Fabrication Sequence
Structural and Multidisciplinary Optimization, 2019Co-Authors: Weiming Wang, D.p. Munro, Charlie C. L. Wang, A. Van KeulenAbstract:The design of optimal structures and the planning of (additive manufacturing) Fabrication Sequences have been considered typically as two separate tasks that are performed consecutively. In the light of recent advances in robot-assisted (wire-arc) additive manufacturing which enable addition of material along curved surfaces, we present a novel topology optimization formulation which concurrently optimizes the structure and the Fabrication Sequence. For this, two sets of design variables, i.e., a density field for defining the structural layout, and a time field which determines the Fabrication process order, are simultaneously optimized. These two fields allow to generate a Sequence of intermediate structures, upon which manufacturing constraints (e.g., Fabrication continuity and speed) are imposed. The proposed space-time formulation is general, and is demonstrated on three Fabrication settings, considering self-weight of the intermediate structures, process-dependent critical loads, and time-dependent material properties.
József Farkas - One of the best experts on this subject based on the ideXlab platform.
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Minimum cost design of a cellular plate loaded by uniaxial compression
Structural and Multidisciplinary Optimization, 2012Co-Authors: Károly Jármai, József FarkasAbstract:Cellular plates are constructed from two base plates and an orthogonal grid of stiffeners welded between them. Halved rolled I-section stiffeners are used for Fabrication aspects. The torsional stiffness of cells makes the plate very stiff. In the case of uniaxial compression the buckling constraint is formulated on the basis of the classic critical stress derived from the Huber’s equation for orthotropic plates. The cost function contains the cost of material, assembly and welding and is formulated according to the Fabrication Sequence. The unknown variables are the base plate thicknesses, height of stiffeners and numbers of stiffeners in both directions. The cellular plate is lighter and cheaper than the plate stiffened on one side. The Particle Swarm Optimization and the IOSO techniques are used to find the optimum. PSO contains crazy bird and dynamic inertia reduction criteria, IOSO is based on a response surface technology.
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Optimum Design of a Belt-Conveyor Bridge Constructed as a Welded Ring-Stiffened Cylindrical Shell
Welding in the World, 2004Co-Authors: József Farkas, Károly Jármai, Zdravko ViragAbstract:In the structural optimization of a ring-stiffened cylindrical shell the unknown variables are the shell thickness as well as the thickness and the number of flat rings. The shell diameter enables to realize a belt-conveyor structure inside of the shell. The uniformly distributed vertical load consists of dead and live load. The design constraints relate to the local shell buckling strength, to the panel ring buckling and to the deflection of the simply supported bridge. The cost function includes the material and Fabrication costs. The Fabrication cost function is formulated according to the Fabrication Sequence and includes also the cost of forming of shell elements into the cylindrical shape as well as the cost of cutting of the flat plate ring-stiffeners. Since the shell thickness does not depend on the number of ring-stiff-eners (n), the n_opt is calculated for a selected region of n.
Kazuhiro Hane - One of the best experts on this subject based on the ideXlab platform.
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Compact Triangulation Sensor Array Constructed by Wafer Bending
Japanese Journal of Applied Physics, 2005Co-Authors: Satoshi Endou, Minoru Sasaki, Masahiro Ishimori, Kazuhiro HaneAbstract:An optical triangulation distance sensor array was constructed by bending a silicon wafer. Since bending is the final process in the Fabrication Sequence, planar photolithography can be included in the Fabrication Sequence. The elements on the Si wafer are all prealigned under a planar condition, and the position-sensitive detector, mirror, and alignment pit for the collimation ball lens are prepared before bending the wafer. The size of the optical bench produced by the sensor substrate is 1.4 mm deep. By batch Fabrication, a 2×2 sensor array was produced. A dynamic range of 4 mm and a noise level of ±1% was confirmed by testing.
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Compact triangulation distance sensor realized by wafer bending technique
MEMS MOEMS and Micromachining, 2004Co-Authors: Minoru Sasaki, Satoshi Endou, Kazuhiro HaneAbstract:The triangulation distance sensor is constructed using the originally proposed wafer bending technique. Since the bending process is final in the Fabrication Sequence, the planer photolighography can be combined. On the Si wafer, the elements are pre-aligned at the unfolded planer condition. The position sensitive detector (PSD), mirror, and alignment pit for the collimation ball lens are prepared. The realized sensor substrate is 1.4mm in depth. Taking the advantage of the batch Fabrication, 2x2 sensor array is prepared. The dynamic range of 4mm with ± 1% noise is confirmed.
