scholarly journals Catalytic conversion of isopropyl alcohol on the heteropolic acid –titanium oxide system

2021 ◽  
Vol 102 (2) ◽  
pp. 53-62
Author(s):  
E.A. Guseinova ◽  
◽  
K.Yu. Adzhamov ◽  
S.E. Yusubova ◽  
◽  
...  

A complex of modern physicochemical methods (X-ray phase analysis, low-temperature adsorption of nitrogen, scanning electron microscopy, element analysis)was used to studythe phase and texture properties of the phosphomolybdenum heteropoly acid–titanium oxide catalytic system. It was found that the optimal content of phosphomolybdenum heteropoly acid, which leads to an increase in the catalytic activity of titanium dioxide, is 7% wt.: the diisopropyl ether yield is higher,it reaches maximum values in a shorter period of time, and the samples are characterized by greater stability. It is shown that the textural characteristics of the specific surface area and dispersion are not the key factors responsible for the catalytic activity.It has been suggested that the activity of phosphomolybdenum heteropoly acid-containing samples is associated with the emergence of a new type of active centers that exhibit increased electron-donorproperties(terminal oxygen atoms of the outer frag-ments of octahedra М = О heteropolyacids). A drop in the catalytic activity of samples with a phosphomolyb-denum heteropoly acid content of more than 7% wt. associated with the formation of surface metaphosphoric acid and entails a decrease in active centers.

2011 ◽  
Vol 55-57 ◽  
pp. 664-669
Author(s):  
Jin Ning Nie ◽  
Hui Wang ◽  
De Feng Xie

According to the situation that the dual-friction drums on the new type towing machine lack stress analysis when designed, the safety is difficult to test and verify. The pull of wire rope in various positions was derived and calculated, so both compressive stress and tangent friction force generated by the pull of wire rope were calculated. The result made by ANSYS software demonstrates the safety of the left drum which suffers from larger loads, structure improvement measures are put forward for the drum.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1203-1207
Author(s):  
Yan Lin ◽  
Xue Jun Zhou ◽  
Yu Chen Liu ◽  
Wen Qing Kong

A new type of concrete-filled square steel tubular column to steel-encased concrete composite beam joint is proposed. In order to study the influences of parameters on bearing capacity for the joint formed plastic hinge in the beam end, nonlinear finite element analysis under monotonic loading is conducted by software ANSYS. The results show that axial compression ratio has little influence on joint bearing capacity, and with the increasing of it, the bearing capacity is enhanced slightly. The height of U-shape steel has a significant impact on joint bearing capacity, and with the rise of it, the bearing capacity is enhanced obviously. The thickness of U-shape steel has a comparatively obvious effect on joint bearing capacity with certain limits, and with the growth of it, the bearing capacity of the joint is also grown observably. The diameter of longitudinal reinforcement in the flange slab of beam has some effects on joint bearing capacity, and with the improvement of diameter, the bearing capacity is achieved.


2010 ◽  
Vol 139-141 ◽  
pp. 938-942
Author(s):  
Ji Jing Lin ◽  
Yan Hong Chen

MFPSE, Micro Free Piston Swing Engine, is a new type of miniature internal combustion engine based on the working principle of two-stroke swing engine. The successful development and operation of this type of miniature internal combustion engine provide important significance for the miniaturization of the internal combustion engine, and provide a number of important research theory, computation method and experimental data. In this article, according to the work characteristics and co-ordination requirements of MFPSE (Micro Free Piston Swing Engine), whose strain interference is analyzed using finite element analysis software, the problems and interference of the center pendulum and cylinder is found evidently. The data of analysis provides theory basis for the MFPSE’s structural optimization, and is critical to improve the performance of MFPSE.


2014 ◽  
Vol 644-650 ◽  
pp. 455-458
Author(s):  
Yao Ye ◽  
Yong Hai Wu

Frame has important effects on the performance of the whole of heavy semi-trailer. A heavy semi-trailer frame is analyzed and researched on in the finite-element way in this article. The frame of 3D geometric model is established by using Pro/E. And it was imported into the Hypermesh to establish frame finite element model. Frame are calculated by using ANSYS solver in bending condition, emergency braking conditions and rapid turn conditions of stress and deformation conditions. The computational tools and methods we used provide the new type of frame and development with a reference method to refer to in this paper.


Author(s):  
Shufeng Sun

To adapt the miniaturized development tendency of nanometer positioning devices, a new type of micro-displacement stage with six degree of freedom, which can implement nanometer-level ultra-precision positioning without feedback control is designed. It takes a group of piezoelectric ceramics actuators (PZTAs) connected in series as actuation unit, takes flexure hinges as elastic guide rail. To overcome the non-linearity and hysteresis of PZTAs, binary actuation principle is adopted to control a group of actuators that work together to output many discrete, repeatable displacements. If these displacements are distributed within a scope of several microns, only simple on and off actuator commands may obtain nanometer-level repeatable positioning without feedback control. Theoretical calculation and finite element analysis (FEA) are used to design and simulate the stage. Expressions of rigidity and stress are obtained by theoretical calculation. FEA and experimental results verify the rationality and feasibility of the stage.


2020 ◽  
Vol 94 (2) ◽  
pp. 301-309
Author(s):  
E. A. Guseinova ◽  
K. Yu. Adzhamov ◽  
S. E. Yusubova

2007 ◽  
Vol 342-343 ◽  
pp. 829-832
Author(s):  
J.M. Luo ◽  
L. Zheng ◽  
X.H. Shi ◽  
Yao Wu ◽  
Xing Dong Zhang

Stress concentration is one of the main mechanical problems leading to the failure of clinical application for osteointegrated implant of percutaneous osteointegrated prosthesis, which is especially marked for higher amputated leg prosthesis. Traditionally design was composed of only the distal part. To improve the biomechanical safety, a new design with the lag part similar to the lag screw was introduced. Based on CT scan data, relatively accurate model of femur for finite element analysis (FEA) were obtained. The FEA results with the new implant demonstrated that compared to traditional design, the declination of bone stress peak ranged from 15.68% to 28.67%, perpendicular deformation from 34.73% to 72.16%, and maximal stress of implant from 14.51% to 23.36% with the increasing of loads from 3750N to 2000N. So the new design of osteointegrated implant would be more secure mechanically, in the case of higher amputated leg attachment.


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