Optimization of Technological Parameters of the Process for Obtaining a Strip by the Combined Method of Metal Casting and Deformation

2020 ◽  
Vol 992 ◽  
pp. 473-479
Author(s):  
V.V. Chernomas ◽  
S.N. Khimukhin ◽  
T.S. Khimukhina

In order to obtain high-quality metal products with the desired properties (process stability) using the combined methods of metal casting and deformation, it is necessary to take into account the specific parameters of this process and the fact that the metal in the crystallizer stays simultaneously in several physical states: liquid, liquid-solid, solid-liquid and solid. Structurally, the mold consists of four walls moving relative each other along a given sophisticated trajectory. The object of the research is the production technology from non-ferrous alloys using the combined method of continuous casting and metal pressure treatment. The thermal processes occurring in the mold of a continuous horizontal metal casting and deformation installation (CHMCDI) during the formation of metal products have been examined as a research subject. The methods of physical modeling of the thermal processes which take place in the system “crystallizing metal-tool deformation” under different conditions of the mold cooling (using closed-perforated tubes and straight-flow tubes) have been used. Subsequent data processing of the full factorial experiment using the least square method as well as solving the optimization problem by using the Pareto principle of optimality made it possible to determine the optimal parameters for the process of obtaining metal products from aluminum alloys (TV = 40 oС; рv = 0.7 kg / cm2; SR = 5.8), which have been confirmed by the results of the experimental test on obtaining the strip from technical aluminum AD0 strip with a cross section of 40–12 mm.

2011 ◽  
Vol 148-149 ◽  
pp. 1260-1263
Author(s):  
Bin Chen ◽  
Ge Liu ◽  
Xian Ming Zhang

As the characteristic of high velocity arc spraying(HVAS)restoration are nonlinear, time-varying and multi-model, it is challenge to identify the model, Takagi-Sugeno (T_S) fuzzy model of abrasion resistance of HVAS coating and technological parameters is proposed. The identification method is presented identifying the consequent parameters with least square method and identifying the input space location and the clustering centre with Fuzzy C-Means Clustering Algorithm. T-S fuzzy model of HVAS tested at the term of examination data, the predictive model and the experiment have the deviation within the-8.6-5.8% limits to abrasion resistance,-8-8% limits to compactness properties.


1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.


2015 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Miftahol Arifin

The purpose of this research is to analyze the influence of knowledge management on employee performance, analyze the effect of competence on employee performance, analyze the influence of motivation on employee performance). In this study, samples taken are structural employees PT.centris Kingdom Taxi Yogyakarta. The analysis tool in this study using multiple linear regression with Ordinary Least Square method (OLS). The conclusion of this study showed that the variables of knowledge management has a significant influence on employee performance, competence variables have an influence on employee performance, motivation variables have an influence on employee performance, The analysis showed that the variables of knowledge management, competence, motivation on employee performance.Keywords: knowledge management, competence, motivation, employee performance.


2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.


2009 ◽  
Vol 29 (4) ◽  
pp. 994-996
Author(s):  
De-quan SUN ◽  
Jun ZHANG ◽  
Xiao-feng LI ◽  
Hui LI

1998 ◽  
Vol 37 (12) ◽  
pp. 335-342 ◽  
Author(s):  
Jacek Czeczot

This paper deals with the minimal-cost control of the modified activated sludge process with varying level of wastewater in the aerator tank. The model-based adaptive controller of the effluent substrate concentration, basing on the substrate consumption rate and manipulating the effluent flow rate outcoming from the aerator tank, is proposed and its performance is compared with conventional PI controller and open loop behavior. Since the substrate consumption rate is not measurable on-line, the estimation procedure on the basis of the least-square method is suggested. Finally, it is proved that cooperation of the DO concentration controller with the adaptive controller of the effluent substrate concentration allows the process to be operated at minimum costs (low consumption of aeration energy).


2020 ◽  
Vol 165 ◽  
pp. 03009
Author(s):  
Li Yan-yi ◽  
Huang Jin ◽  
Tang Ming-xiu

In order to evaluate the performance of GPS / BDS, RTKLIB, an open-source software of GNSS, is used in this paper. In this paper, the least square method, the weighted least square method and the extended Kalman filter method are respectively applied to BDS / GPS single system for data solution. Then, the BDS system and GPS system are used for fusion positioning and the positioning results of the two systems are compared with that of the single system. Through the comparison of experiments, on the premise of using the extended Kalman filter method for positioning, when the GPS signal is not good, BDS data is introduced for dual-mode positioning, the positioning error in e direction is reduced by 36.97%, the positioning error in U direction is reduced by 22.95%, and the spatial positioning error is reduced by 16.01%, which further reflects the advantages of dual-mode positioning in improving a system robustness and reducing the error.


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