Research on Level 2 Rolling Model of Tin Plate Double Cold Reduction Process

Author(s):  
Hui Wang ◽  
Wei Guo ◽  
Yanglong Li ◽  
Fei Chen ◽  
Jie Wen ◽  
...  
2013 ◽  
Vol 631-632 ◽  
pp. 708-712
Author(s):  
Bong Joon Kim ◽  
Eun Soo Park ◽  
Won Yong Byeon ◽  
Dal Joon Cha ◽  
Yong Nam Kwon

In this study, cold reduction process of the tubular metal is applied to manufacture the drive shaft for the rear wheel drive system. With this method during forming process, chip forming such as hobbing and broaching method is not involved. The manufacturing process is as follows; the tube which the sheet is formed and welded to by roll forming machine, is mounted on a suitable mandrel. This mandrel has an external toothing which corresponds to internal toothing of the final product. During axial moving and rotating of the workpiece, forming operation is carried out in lengthwise direction of the toothing. This forming rolls is positioned on the roll head and have a rolling axis vertical with the one of a mandrel. The total forming load needed in the cold reduction process is separated into numerous forming steps along the entire cylindrical length of the zone to be formed. In the process of cold forming on the profiled mandrel during the impact forming operation, material is pushed into depression of toothing of a mandrel mainly in a radial direction. Finally splines can be generated on the surface of components and overall elongated. If the process parameter such as the length of forming per 1rotation of 1roll is not optimized, the impact force from the rolls of the forming process causes geometrical defects. So the optimal parameters such as feeding and rotating speed of workpiece and the forming length should be properly determined. And the effects of the weld line positioning on the formability of the forming process is analyzed to minimize the generation of the defects such as crack on the surface of splined zone.


Author(s):  
Douglas William Jones

Within the past 20 years, archaeobotanical research in the Eastern United States has documented an early agricultural complex before the dominance of the Mesoamerican domesticates (corn, beans, and squash) in late prehistoric and historic agricultural systems. This early agricultural complex consisted of domesticated plants such as Iva annua var.macrocarpa (Sumpweed or Marshelder), Hellanthus annuus (Sunflower) and Chenopodium berlandieri, (Goosefoot or Lasbsquarters), and heavily utilized plants such as Polygonum erectum (Erect Knotweed), Phalaris caroliniana (May grass), and Hordeum pusillum (Little Barley).Recent research involving the use of Scanning Electron Microscopy (SEM) specifically on Chenopodium has established diagnostic traits of wild and domesticated species seeds. This is important because carbonized or uncarbonized seeds are the most commonly recovered Chenopodium material from archaeological sites. The diagnostic seed traits assist archaeobotanists in identification of Chenopodium remains and provide a basis for evaluation of Chenopodium utilization in a culture's subsistence patterns. With the aid of SEM, an analysis of Chenopodium remains from three Late Prehistoric sites in Northwest Iowa (Blood Run [Oneota culture], Brewster [Mill Creek culture], and Chan-Ya-Ta [Mill Creek culture]) has been conducted to: 1) attempt seed identification to a species level, 2) evaluate the traits of the seeds for classification as either wild or domesticated, and 3) evaluate the role of Chenopodium utilization in both the Oneota and Mill Creek cultures.


2018 ◽  
Author(s):  
Handan Özek Erkuran ◽  
Şermin Yalin Sapmaz ◽  
Ahmet Herdem ◽  
Masum Öztürk ◽  
Öznur Bilaç ◽  
...  

1998 ◽  
Vol 10 (1-3) ◽  
pp. 57-72 ◽  
Author(s):  
K. S. B. Keats-Rohan

The COEL database and database software, a combined reference and research tool created by historians for historians, is presented here through Screenshots illustrating the underlying theoretical model and the specific situation to which that has been applied. The key emphases are upon data integrity, and the historian's role in interpreting and manipulating what is often contentious data. From a corpus of sources (Level 1) certain core data are extracted for separate treatment at an interpretive level (Level 3), based upon a master list of the core data (Level 2). The core data are interdependent: each record in Level 2 is of interest in itself; and it either could or should be associated with an(other) record(s) as a specific entity. Sometimes the sources are ambiguous and the association is contentious, necessitating a probabilty-coding approach. The entities created by the association process can then be treated at a commentary level, introducing material external to the database, whether primary or secondary sources. A full discussion of the difficulties is provided within a synthesis of available information on the core data. Direct access to the source texts is only ever a mouse click away. Fully query able, COEL is formidable look-up and research tool for users of all levels, who remain free to exercise an alternative judgement on the associations of the core data. In principle, there is no limit on the type of text or core data that could be handled in such a system.


2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
Author(s):  
A. M. Abdelghany ◽  
A.H. Oraby ◽  
Awatif A Hindi ◽  
Doaa M El-Nagar ◽  
Fathia S Alhakami

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.


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