Free Form Fabrication—Process Overview

2000 ◽  
pp. 287-323
Author(s):  
Sean O’Reilly
Keyword(s):  
Fabrication Process ◽  
Free Form

Characteristics of Free Form Finishing Applying V-CAM System

2007 ◽  
Vol 329 ◽  
pp. 273-278
Author(s):  
Wei Min Lin ◽  
Hitoshi Ohmori ◽  
T. Suzuki ◽  
Yoshihiro Uehara ◽  
Y. Watanabe ◽  
...  
Keyword(s):  
Research And Development ◽  
Fabrication Process ◽  
Free Form ◽  
Polished Surface ◽  
Precision Control ◽  
Form Accuracy ◽  
Cad System ◽  
Free Form Surface ◽  
The Relationship ◽  
Fundamental Experiment

A new CAD system, which is called Volume-CAD (VCAD) have been developed. We carried out research and development of VCAD fabrication process based on VCAD/CAM precision control. In this study, a developed V-CAM had been used for a polishing fundamental experiment of a free form surface. The relationship between NC resolution and form accuracy of polished surface are discussed.

3D Free Form Fabrication Using the Pivoting Side Trowel with Ceramic Material

2010 ◽  
Vol 658 ◽  
pp. 268-271 ◽  
Author(s):  
Hong Kyu Kwon ◽  
Moo Kyung Jang
Keyword(s):  
Ceramic Material ◽  
Computer Control ◽  
Fabrication Process ◽  
Free Form ◽  
Contour Crafting ◽  
Construction Automation ◽  
Initial Investigation ◽  
Superior Surface

This paper presents our concepts and initial investigation of a novel construction automation approach using a new layered fabrication process called Contour Crafting (CC). The process aims at automated construction of whole houses as well as sub-components. The potential of CC became evident from the initial investigations and experiments with various materials and geometries. Using this process, a single house or a colony of houses, each with possibly a different design, may be automatically constructed in a single run. CC uses computer control to take advantage of the superior surface forming capability of trowels to create large intricate structures with smooth and accurate surfaces.

2613 Development of Super Finishing Tool for Large Free Form Surface : 1^ report: Approach to a fabrication process of large free form mirrors

2005 ◽  
Vol 2005.4 (0) ◽  
pp. 63-64
Author(s):  
Hitoshi OHMORI ◽  
Weimin LIN ◽  
Shin-ya MORITA ◽  
Yoshihiro UEHARA ◽  
Yutaka WATANABE ◽  
...  
Keyword(s):  
Fabrication Process ◽  
Free Form ◽  
Free Form Surface ◽  
Finishing Tool

Modeling of Multifunctional Porous Tissue Scaffolds With Continuous Deposition Path Plan

2012 ◽  
Author(s):  
A. K. M. B. Khoda ◽  
Ibrahim T. Ozbolat ◽  
Bahattin Koc
Keyword(s):  
Pore Size ◽  
Tool Path ◽  
Medial Axis ◽  
Tissue Scaffolds ◽  
Fabrication Process ◽  
Free Form ◽  
Tissue Scaffold ◽  
Medial Axis Transformation ◽  
Material Deposition ◽  
Continuous Material

A novel modeling technique for porous tissue scaffolds with targeting the functionally gradient variational porosity with continuous material deposition planning has been proposed. To vary the porosity of the designed scaffold functionally, medial axis transformation is used. The medial axis of each layers of the scaffold is calculated and used as an internal feature. The medial axis is then used connected to the outer contour using an optimum matching. The desired pore size and hence the porosity have been achieved by discretizing the sub-regions along its peripheral direction based on the pore size while meeting the tissue scaffold design constraints. This would ensure the truly porous nature of the structure in every direction as well as controllable porosity with interconnected pores. Thus the desired controlled variational porosity along the scaffold architecture has been achieved with the combination of two geometrically oriented consecutive layers. A continuous, interconnected and optimized tool-path has been generated for successive layers for additive-manufacturing or solid free form fabrication process. The proposed methodology has been computationally implemented with illustrative examples. Furthermore, the designed example scaffolds with the desired pore size and porosity has been fabricated with an extrusion based bio-fabrication process.

scholarly journals BIM-Based Digital Fabrication Process for a Free-Form Building Project in South Korea

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Joo-sung Lee ◽  
Nahyun Kwon ◽  
Nam-hyuk Ham ◽  
Jae-jun Kim ◽  
Yong-han Ahn
Keyword(s):  
South Korea ◽  
Digital Fabrication ◽  
Fabrication Process ◽  
Information Modeling ◽  
Free Form ◽  
Productivity Analysis ◽  
Analysis Model ◽  
Queuing Model ◽  
Building Information ◽  
And Performance

Since the concept of building information modeling (BIM) was introduced in South Korea in 2008, digital fabrication concerning free-form shapes and complex parametric information has been expanding owing to the development of BIM software and tools. However, the digital fabrication process is inadequate in terms of efficiency and productivity because of the need to convert from conventional two-dimensional (2D) drawings to a BIM design; this adversely affects the unified design, fabrication, installation, and inspection processes. Moreover, an optimized process has not been developed thus far because the productivity of digital fabrication has not been quantitatively verified for various projects in the field. This study proposes a BIM-based digital fabrication process for prefabricated parts of buildings. In addition, a productivity analysis method based on the queuing model is proposed using personnel input and performance calculation data to verify productivity. It is expected that the digital fabrication process and productivity analysis model proposed here will be applied to complex digital fabrication works.

Linewidth measurement using the low voltage SEM

1986 ◽  
Vol 44 ◽  
pp. 652-653
Author(s):  
M.G. Rosenfield
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Secondary Electron ◽  
Low Voltage ◽  
Fabrication Process ◽  
Critical Dimensions ◽  
Linewidth Measurement ◽  
Threshold Technique ◽  
Scanning Electron

Minimum feature sizes in experimental integrated circuits are approaching 0.5 μm and below. During the fabrication process it is usually necessary to be able to non-destructively measure the critical dimensions in resist and after the various process steps. This can be accomplished using the low voltage SEM. Submicron linewidth measurement is typically done by manually measuring the SEM micrographs. Since it is desirable to make as many measurements as possible in the shortest period of time, it is important that this technique be automated.Linewidth measurement using the scanning electron microscope is not well understood. The basic intent is to measure the size of a structure from the secondary electron signal generated by that structure. Thus, it is important to understand how the actual dimension of the line being measured relates to the secondary electron signal. Since different features generate different signals, the same method of relating linewidth to signal cannot be used. For example, the peak to peak method may be used to accurately measure the linewidth of an isolated resist line; but, a threshold technique may be required for an isolated space in resist.

Minimal contribution of cell-bound antibodies to the immunoscintigraphy of inflamed joints with 99mTc-anti-CD4 monoclonal antibodies

2002 ◽  
Vol 41 (03) ◽  
pp. 129-134 ◽  
Author(s):  
A. Wolski ◽  
E. Palombo-Kinne ◽  
F. Wolf ◽  
F. Emmrich ◽  
W. Becker ◽  
...  
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
Synovial Membrane ◽  
In Vitro Release ◽  
Peritoneal Macrophages ◽  
Lymphoid Organs ◽  
Whole Body ◽  
Free Form ◽  
Ankle Joints

Summary Aim: The cellular joint infiltrate in rheumatoid arthritis patients is rich in CD4-positive T-helper lymphocytes and macrophages, rendering anti-CD4 monoclonal antibodies (mAbs) suitable for specific immunoscintigraphy of human/ experimental arthritis. Following intravenous injection, however, mAbs are present both in the free form and bound to CD4-positive, circulating monocytes and T-cells. Thus, the present study aimed at analyzing the relative contribution of the free and the cell-bound component to the imaging of inflamed joints in experimental adjuvant arthritis (AA). Methods: AA rat peritoneal macrophages or lymph node T-cells were incubated in vitro with saturating amounts of 99mTc-anti-CD4 mAb (W3/25) and injected i.v. into rats with AA. Results: In vitro release of 99mTc-anti-CD4 mAb from the cells was limited (on average 1.57%/h for macrophages and 0.84%/h for T-cells). Following i.v. injection, whole body/joint scans and tissue measurements showed only negligible accumulation of radioactivity in inflamed ankle joints (tissue: 0.22 and 0.34% of the injected activity, respectively), whereas the radioactivity was concentrated in liver (tissue: 79% and 71%, respectively), kidney, and urinary bladder. Unlike macrophages, however, anti-CD4 mAb-coated T-cells significantly accumulated in lymphoid organs, the inflamed synovial membrane of the ankle joints, as well as in elbow and knee joints. Conclusion: While the overall contribution of cell-bound mAbs to the imaging of arthritic joints with anti-CD4 mAbs is minimal, differential accumulation of macrophages and T-cells in lymphoid organs and the inflamed synovial membrane indicates preferential migration patterns of these 2 cell populations in arthritic rats. Although only validated for 99mTc-anti-CD4 mAbs, extrapolation of the results to other anticellular mAbs with similar affinity for their antigen may be possible.

Immunoreactivity of Tissue Plasminogen Activator and of Its Inhibitor Complexes

1989 ◽  
Vol 61 (03) ◽  
pp. 409-414 ◽  
Author(s):  
M Rånby ◽  
G Nguyen ◽  
P Y Scarabin ◽  
M Samama
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Degradation Products ◽  
Gel Filtration ◽  
Free Form ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Significant Difference ◽  
Tissue Plasminogen ◽  
Pai 1

SummaryAn enzyme linked immunosorbent assay (ELISA) based on goat polyclonal antibodies against human tissue plasminogen activator (tPA) was evaluated. The relative immunoreactivity of tPA in free form and tPA in complex with inhibitors was estimated by ELISA and found to be 100, 74, 94, 92 and 8l% for free tPA and tPA in complex with PAI-1, PAI-2, α2-antiplasmin and C1-inhibitor, respectively. Addition of tPA to PAI-1 rich plasma resulted in rapid and total loss of tPA activity without detectable loss of ELISA response, indicating an immunoreactivity of tPA in tPA/PAI-1 complex of about l00%. Three different treatments of citrated plasma samples (acidification/reneutralization, addition of 5 mM EDTA or of 0.5 M lysine) prior to determination by ELISA all resulted in increased tPA levels. The fact that the increase was equally large in all three cases along with good analytical recovery of tPA added to plasffi, supported the notion that all tPA antigen present in plasma samples is measured by the ELISA. Analysis by ELISA of fractions obtained by gel filtration of plasma from a patient undergoing tPA treatment identified tPA/inhibitor complexes and free tPA but no low molecular weight degradation products of tPA. Determinations of tPA antigen were made at seven French clinical laboratories on coded and randomized plasma samples with known tPA antigen content. For undiluted samples there was no significant difference between the tPA levels found and those known to be present. The between-assay coefficient of variation was 7 to 10%. In conclusion, the ELISA appeared suited for determination of total tPA antigen in human plasma samples.

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