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211.
A practical approach towards mathematical modeling of deposition rate during twin-wire submerged arc welding 总被引:1,自引:1,他引:0
Abhay Sharma Navneet Arora Bhanu K. Mishra 《The International Journal of Advanced Manufacturing Technology》2008,36(5-6):463-474
The present paper deals with a shop floor applicable mathematical model for deposition rate during twin-wire submerged arc
welding. The salient features of this model are (1) instead of melting rate, as modeled during past investigations, it quantifies
the deposition rate, which is the actual outcome of the process and always remains smaller than the melting rate because of
evaporation or spatters losses and (2) it estimates electrode extension in order to predict the deposition rate which makes
the proposed model more practical than the models constituted with the help of experimental measurement of electrode extension.
The model is more scientific than the simplified models where contact tube to work-piece distance has been considered as the
electrode extension. A critical review of the relevant past investigation is given and a mathematical model is developed for
deposition rate during the twin-wire welding with both the polarities, i.e., direct current electrode positive and direct
current electrode negative. The model is calibrated using the results of 200 experimental runs and it is found to be very
accurate with very high coefficient of regression and admissible standard error. The developed model is further validated
with extra experimental runs. The practicality of the considered approach for prediction of deposition rate can further be
used in future research for other consumable arc welding processes. 相似文献
212.
213.
G Ginther RM Edelstein CP Forsyth K Gamarnik AE Kreymer RJ Lipton JM McQuade DM Potter JS Russ L Spiegel DE Johnson D Buchholz LM Cremaldi SW Delchamps HS Mao JL Rosen W Sakumoto RA Schluter SB Sontz C Winter JM Bishop NN Biswas NM Cason L Dauwe J Godfrey VP Kenney P Mooney R Pemper E Rojek RC Ruchti M Sarmiento WD Shephard 《Canadian Metallurgical Quarterly》1987,35(5):1541-1552
214.
215.
216.
Rakesh Kumar Soni Harjeet Singh Krishna Dutt Priyanka Arora 《Journal of Polymer Research》2010,17(3):411-427
The mixing torque behavior of ter blends of isotactic-polypropylene (iPP) with ethylene-propylene diene rubber (EPDM)/Nitrile
rubber (NBR) was studied with the help of Rheometer using resole type phenolic resin as a cross-linking agents. Systematic
changes with varying blend composition were observed in stress-strain behavior in the yield region viz., width of yield peak,
work of yield, yield stress and yield strain. Analysis of yield stress data was made on the basis of various mathematical
expressions of first power and two-thirds power laws of blend composition dependence and the porosity model. It led to consistent
result from the expressions about the variation of stress concentration effect in both uncross-linked and cross-linked blend
systems. With the aid of scanning electron microscopy (SEM) shapes and sizes of dispersed elastomer phase (EPDM / NBR) domains
at varying blend compositions were studied. 相似文献
217.
Deepti Mishra Ruma Arora Swati Lahiri Sudhir Sitaram Amritphale Navin Chandra 《Protection of Metals and Physical Chemistry of Surfaces》2014,50(5):628-631
In the present work iron oxide nanoparticles have been synthesized by alkaline solvo thermal method using anhydrous ferric chloride, sodium hydroxide, polyethylene glycol and cetyl trimethyl ammonium bromide and characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray Spectroscopy (EDX) and Thermal Gravimetric Analysis (TGA). XRD indicated that the product is a mixture of different phases of iron oxide viz. gamma-Fe2O3 (maghemite, tetragonal), Fe2O3 (maghemite, cubic), Fe3O4 (magnetite, cubic) and ?-Fe2O3(epsilon iron oxide). FESEM studies indicated that size of the particles is observed in the range of about 19.8 nm to 48 nm. EDX spectral analysis reveals the presence of carbon, oxygen, iron in the synthesized nanoparticles. The FTIR spectra indicated absorption bands due to O-H stretching, C-O bending, N-H stretching and bending, C-H stretching and Fe-O stretching vibrations. TGA curve represented weight loss of around 3.0446 % in the sample at temperature of about 180°C due to the elimination of the water molecules absorbed by the nanoparticles from the atmosphere. 相似文献
218.
219.
LG Yu DG Fernig MR White DG Spiller P Appleton RC Evans I Grierson JA Smith H Davies OV Gerasimenko OH Petersen JD Milton JM Rhodes 《Canadian Metallurgical Quarterly》1999,274(8):4890-4899
The Galbeta1-3GalNAcalpha (TF antigen)-binding lectin (ABL) from the common edible mushroom (Agaricus bisporus) has a potent anti-proliferative effect without any apparent cytotoxicity. This unusual combination of properties prompted investigation of its mechanism of action. In contrast to soluble lectin, agarose-immobilized, and hence noninternalizable ABL had no effect on proliferation of HT29 colon cancer cells. Electron microscopy of HT29 cells incubated with fluorescein- and gold-conjugated ABL showed internalization of the lectin into endocytotic vesicles and multivesicular bodies. Confocal microscopy showed perinuclear accumulation of fluorescein isothiocyanate-conjugated lectin, which also inhibits HT29 cell proliferation, raising the possibility that the lectin might interfere with nuclear pore function. Transport of heat shock protein 70 into the nucleus in response to heat shock was blocked by preincubation of HT29 cells for 6 h with 40 micrograms/ml ABL. In digitonin-permeabilized cells, nuclear uptake of bovine albumin conjugated to a nuclear localization sequence (NLS)-containing peptide was also inhibited by a 15-min preincubation with 40-100 micrograms/ml ABL. In contrast, serum-stimulated nuclear translocation of mitogen-activated protein kinase, which is NLS-independent, was not affected by pretreatment of cells with the lectin. These results suggest that the anti-proliferative effect of ABL is likely to be a consequence of the lectin trafficking to the nuclear periphery, where it blocks NLS-dependent protein uptake into the nucleus. 相似文献
220.
Basak AK; Kroone RC; Lubsen NH; Naylor CE; Jaenicke R; Slingsby C 《Protein engineering, design & selection : PEDS》1998,11(5):337-344
The 2-domain gammaS-crystallin, a highly conserved early evolutionary
off-shoot of the gamma-crystallin family, is located in the water-rich
region of eye lenses. The expressed C-terminal domain, gammaS-C, has been
crystallized and the 2.56 A X-ray structure determined. There are two
domains in the asymmetric unit which pair about a distorted twofold axis.
One of the domains has an altered conformation in a highly conserved region
of the protein, the tyrosine corner. The distorted gammaS-C dimer of
domains is compared with the highly symmetrical, equivalent recombinant
dimer of C-terminal domains from gammaB- crystallin. Sequence changes close
to the interface, that distinguish gammaS from the other gamma-crystallins,
are examined in order to evaluate their role in symmetrical domain pairing.
相似文献