A uniform dispersion equation in a multichannel problem

1982 ◽  
Vol 19 (4) ◽  
pp. 1335-1344
Author(s):  
V. S. Buldyrev ◽  
N. S. Grigor'eva
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.


2011 ◽  
Vol 17 (1) ◽  
pp. 43-46 ◽  
Author(s):  
G.V. Lizunov ◽  
◽  
A.Yu. Leontiev ◽  

Alloy Digest ◽  
2013 ◽  
Vol 62 (5) ◽  

Abstract Centralloy G4879 Micro is a cast nickel alloy with very good high-temperature properties. The alloy has carbides in a uniform dispersion that impede dislocation movement. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on casting, machining, and joining. Filing Code: Ni-708. Producer or source: Schmidt & Clemens Inc..


e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 430-442 ◽  
Author(s):  
Rajdeep Mukherjee ◽  
Arun Kumar Mandal ◽  
Susanta Banerjee

AbstractSulfopropylated polysilsesquioxane and –COOH containing fluorinated sulfonated poly(arylene ether sulfone) composite membranes (SPAES-SS-X) have been prepared via an in situ sol–gel reaction through the solution casting technique. The composite membranes showed excellent thermal and chemical stability, compared to the pristine SPAES membrane. The uniform dispersion of the sulfonated SiOPS nanoparticles on the polymer matrix was observed from the scanning electron microscope images. Atomic force microscopy and transmission electron microscopy images indicated significantly better phase-separated morphology and connectivity of the ionic domains of the composite membranes than the pristine SPAES membrane. The composite membranes showed considerable improvement in proton conductivity and oxidative stability than the pristine copolymer membrane under similar test conditions.


Author(s):  
Muhammad Zahid ◽  
Jiang Li ◽  
Ahmed Ismail ◽  
Francisco Zaera ◽  
Yujun Zhu

PtCo/MIL-101(Cr) with high uniform dispersion Pt–Co IMNs synthesized by a polyol reduction method show higher activity for selective catalytic hydrogenation of α,β-unsaturated aldehydes due to the synergistic effect of PtCo and MIL-101(Cr) support.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 184
Author(s):  
Hongwei Zhu ◽  
Haonan Li ◽  
Furen Xiao ◽  
Zhixiang Gao

Self-designed (NbTi)C nanoparticles were obtained by mechanical alloying, predispersed in Fe powder, and then added to 1045 steel to obtain modified cast steels. The microstructure of cast steels was investigated by an optical microscope, scanning electron microscope, X-ray diffraction, and a transmission electron microscope. The results showed that (NbTi)C particles can be added to steels and occur in the following forms: original ellipsoidal morphology nanoparticles with uniform dispersion in the matrix, cuboidal nanoparticles in the grain, and microparticles in the grain boundary. Calculations by Thermo-Calc software and solubility formula show that cuboidal (NbTi)C nanoparticles were precipitated in the grain, while the (NbTi)C microparticles were formed by eutectic transformation. The results of the tensile strength of steels show that the strength of modified steels increased and then declined with the increase in the addition amount. When the addition amount was 0.16 wt.%, the modified steel obtained the maximum tensile strength of 759.0 MPa, which is an increase of 52% compared with to that with no addition. The hardness of the modified steel increased with the addition of (NbTi)C nanoparticles. The performance increase was mainly related to grain refinement and the particle strengthening of (NbTi)C nanoparticles, and the performance degradation was related to the increase in eutectic (NbTi)C.


2020 ◽  
Vol 7 (4) ◽  
pp. 201-203
Author(s):  
Hans-Rudolf Raab

<b>Background:</b> One critical step in the therapy of patients with localized pancreatic cancer is the determination of local resectability. The decision between primary surgery versus upfront local or systemic cancer therapy seems especially to differ between pancreatic cancer centers. In our cohort study, we analyzed the independent judgement of resectability of five experienced high volume pancreatic surgeons in 200 consecutive patients with borderline resectable or locally advanced pancreatic cancer. <b>Methods:</b> Pretherapeutic CT or MRI scans of 200 consecutive patients with borderline resectable or locally advanced pancreatic cancer were evaluated by 5 independent pancreatic surgeons. Resectability and the degree of abutment of the tumor to the venous and arterial structures adjacent to the pancreas were reported. Interrater reliability and dispersion indices were compared. <b>Results:</b> One hundred ninety-four CT scans and 6 MRI scans were evaluated and all parameters were evaluated by all surgeons in 133 (66.5%) cases. Low agreement was observed for tumor infiltration of venous structures (κ = 0.265 and κ = 0.285) while good agreement was achieved for the abutment of the tumor to arterial structures (interrater reliability celiac trunk κ = 0.708 P &#x3c; 0.001). In patients with vascular tumor contact indicating locally advanced disease, surgeons highly agreed on unresectability, but in patients with vascular tumor abutment consistent with borderline resectable disease, the judgement of resectability was less uniform (dispersion index locally advanced vs. borderline resectable p &#x3c; 0.05). <b>Conclusion:</b> Excellent agreement between surgeons exists in determining the presence of arterial abutment and locally advanced pancreatic cancer. The determination of resectability in borderline resectable patients is influenced by additional subjective factors. <b>Trial registration:</b> EudraCT: 2009–014476–21 (2013–02–22) and NCT01827553 (2013–04–09).


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