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rapid-prototyping
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Total 29 records
On the development of direct metal laser sintering for rapid tooling
, Article Journal of Materials Processing Technology ; Volume 141, Issue 3 , 2003 , Pages 319-328 ; 09240136 (ISSN) ; Petzoldt, F ; Pohl, H ; Sharif University of Technology
2003
Abstract
An iron based powder blend has been developed for rapid tooling using a direct laser sintering process. The powder consists of a mixture of different elements including Fe, C, Cu, Mo and Ni. High sintering activities were obtained by tailoring the powder characteristics and optimizing the chemical constituents. The manufacturing of complex-shaped parts is possible at rates of 6.75 cm3/h according to CAD data. The residual porosity is less than 5 vol.%. The bending strength is around 900 MPa and the artifact hardness is 490 HV30. To further improve the service life of tools, the processed parts are sintered again in a vacuum furnace at 1260 °C for 30 min. This enables to manufacture precision...
Rapid design space exploration of DSP applications using programmable SOC devices - A case study
, Article 15th Annual IEEE International ASIC/SOC Conference, ASIC/SOC 2002, 25 September 2002 through 28 September 2002 ; Volume 2002-January , 2002 , Pages 273-277 ; 10630988 (ISSN); 0780374940 (ISBN) ; Sharifì, S ; Gudarzi, M ; Hessabi, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2002
Abstract
In this paper, we present results of our experiments in implementation of a widely used DSP primitive on a programmable SoC (System-on-a-Chip) Device. The DSP primitive is a 16-bit digital FIR filter which we implemented on Triscend E5 CSoC® family. Experimental results show that by properly breaking the DSP task into hardware and software parts, one can achieve higher throughput compared to DSP processor implementations, while having more flexibility and less time-to-design compared to full-hardware realizations. Programmable SoC device facilitates rapid design-space exploration, which we employed to optimize our mixed hardware-software architecture. We compared our filter throughput to...
Design and Fabrication of a 3D Multiparticle Microfluidic System
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor) ; Annabestani, Mohsen (Co-Supervisor)
Abstract
Microfluidic technology is a field of science that deals with the design, implementation, optimization, and testing of fluid systems in small dimensions. This technology has made significant progress in various fields in the last decade, especially in medical engineering. As an interdisciplinary scientific field, this growing technology has many applications in medicine, pharmaceuticals, chemistry, and electronic industries. One of the primary applications of microfluidic devices is the development of "lab-on-a-chip" systems as point-of-care diagnostic tools, such as rapid diagnosis during surgery. A microfluidic system includes various functional modules: sample preparation and fluid...
Design and Assessment of Accuracy of a Patient-Specific Drill Guide Template for Thoracic Pedicle Screw Placement
, M.Sc. Thesis Sharif University of Technology ; Arjmand, Navid (Supervisor)
Abstract
Fusion surgery or fixation of vertebrae in the spine is used to treat scoliosis, fractures, infections, tumors, spinal cord injuries, and disc herniation. In this type of surgery, two or more vertebrae are connected by special screws called pedicle screws to eliminate movement between the vertebrae. Given the serious risks of spinal fusion surgery, if the slightest mistake is made at the entry point or angle of the screw inside the vertebrae, the risk of spinal cord injury is very high, which is one of the complications of fusion surgery. Therefore, in order to increase the accuracy of screw placement, patient-specific template guides are used as drill guides in this operation. For this...
Investigation of the Effect of Additive Manufacturing Process Parameters on the Geometry of Components Made of Inconel 625 by Direct Metal Deposition
, M.Sc. Thesis Sharif University of Technology ; Akbary, Javad (Supervisor) ; Moradi, Mahmoud (Supervisor)
Abstract
Additive manufacturing technology (AM) is one of the new methods of rapid prototyping. Experts claim that using this process can produce a prototype of the product with any complex geometry in the shortest possible time. Among the methods of metal additive fabrication, the direct metal layering method with the powder coaxial nozzle has different capabilities and has received much attention by researchers. In this research, we intend to find a relationship between device parameters and the geometry of samples made by direct metal layer method. According to the research, many parameters affect the quality of the samples made by this method, the most effective of which are the three parameters...
Selection of the Optimal Orientation of Parts in Rapid Prototyping Processes
, M.Sc. Thesis Sharif University of Technology ; Khodaygan, Saeed (Supervisor)
Abstract
Additive manufacturing (AM), also known as Rapid prototyping or D printing, is a new technology for the manufacturing of the physical parts through an additive manner. In the AM process, the orientation pattern of the part is one of the most important factors that significantly affects the product properties such as the build time, the surface roughness, the mechanical strength, the wrinkling, and the amount of support material. The build time and the surface roughness are the more imperative criteria than others that can be considered to find the optimum orientation of parts. In this research, Two method is used to optimize part build orientation (PBO). In the first method a new combined...
Reducing part Warpage by Optimizing Process Parameters in Selective Laser Sintering
, M.Sc. Thesis Sharif University of Technology ; Movahhedy, Mohammad Reza (Supervisor) ; Akbari, Javad (Supervisor)
Abstract
One of the newest methods of rapid prototyping is SLS . In this day, SLS is more common in compare others methods, because it uses little time and man does not nearly interfere in the producing stages of part which is made by SLS method. Also, sophisticated parts, which cannot be built by other methods, can be produced by SLS method. One of the disadvantages of SLS method is low dimensions accuracy of parts produced in this way. This problem has two major reasons: Shrinkage and Warpage. These two phenomena are created because of ununiformed temperature distribution. Others features which have effect on dimensions accuracy are residual stress, porosity and removing space of between powder...
Modeling of the Mechanical Behavior of Rapid Prototyped Scaffolds Based on Their Pore Architecture and Introducing a Prototyping Method to Produce Ceramic Scaffolds
, Ph.D. Dissertation Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Baghaban Eslaminejad, Mohamad Reza (Supervisor)
Abstract
Mechanical behavior of tissue engineering scaffolds plays a key role in their biological performance; however the effect of microstructural features on mechanical behavior of such scaffolds is still under investigation. The objective of this study was to investigate the influence of pore architecture and relative density on mechanical behavior of rapid prototyped scaffolds. In this regard, scaffolds with different cubic, hexagonal and trigonal unit cells were designed. These unit cells were repeated in different arrangements in 3D space to produce different nodal connectivities. The internal dimension of pores varied from 500 to 600 μm. Plastic models of scaffolds then fabricated by 3D...
Design and Analysis of a Robotic Duct Cleaning System
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Gholamreza (Supervisor) ; Ghaemi Osgouie, Kambiz (Supervisor)
Abstract
Delivering high quality and clean air into occupied spaces is the main goal of Heating, Ventilation and Air Conditioning (HVAC) systems. HVAC systems draw supply air which usually contains fungi and moisture. Fungi and moisture plus organic materials create a good bed for mold growth. Studies prove that duct cleaning process can definitely reduce the amount of pollutants present in the ducts. Hence, it has positive impact on human lives both regarding psychological and physical points of view. Duct cleaning method’s application difficulties and ducts’ unreachable environments motivated duct cleaning firms to employ robots for duct cleaning tasks. Although there are considerable numbers of...