scholarly journals Determination of optimal parameters of vibrо-activation of hydrated lime

Author(s):  
A.I. Zahrai ◽  
◽  
Z.I. Borovets' ◽  
I.V. Lutsyuk ◽  
Yа.M. Novitskyi

The method of mechanical activation of hydrated lime in a vibrating activator of bunker type was offered in this work. The influence of design features and angle of fixing of vibrating blades on the speed and degree of dispersion of hydrated lime was investigated by measuring the change in the logarithmic decrement of mass attenuation during vibro-activation. The effect of the duration of the vibro-activation process on the dispersion in the system "hydrated lime–water" was studied. The efficiency of lime dispersion was shown in the case of mounting the blades at the angle of 860 for 40–60 minutes. Comparative studies of the strength of cement stone showed that the addition of vibro-activated hydrated lime in an amount of 2 wt.% leads to an increase in the strength of lime-cement compositions.

1988 ◽  
Vol 21 (5) ◽  
pp. 133-136
Author(s):  
N Zarsav

The use of high frequency ultrasonic Lamb waves to measure the thickness of thin plates and foils, is discussed and the feasibility of their application to the determination of the degree of cure of polymer coating on coated tin plated steel sheet (as used by the food can industry) is evaluated. The paper also discusses briefly the design features of the purpose built precision double probe ultrasonic goniometer used to carry out these measurements.


Author(s):  
Duy-Chinh Nguyen

In this paper, an analytical method is presented to determine the optimal parameters of the symmetric tuned mass damper, such as the ratio between natural frequency of tuned mass damper and shaft (tuning ratio) and the ratio of the viscous coefficient of tuned mass damper (damping ratio). The optimal parameters of tuned mass damper are applied to reduce the torsional vibration of the shaft based on consideration of the vibration duration and stability criterion. The dynamic equations of the shaft are provided via Lagrangian equations, and the optimal parameters of tuned mass damper are derived by using the principle of minimum kinetic energy. Analytical and numerical examples are implemented to verify the reliability of the proposed method. The analytical and numerical results indicate that the optimal parameters of tuned mass damper have significant effects in the torsional vibration reduction of the shaft.


2018 ◽  
Vol 13 (6) ◽  
pp. 50
Author(s):  
Gleb V. Grenkin ◽  
Alexander Yu. Chebotarev ◽  
Valeri I. Babushok ◽  
Sergey S. Minaev

The optimization procedure was developed to derive the global kinetic parameters using experimental dependence of burning velocity on the equivalence ratio. The simple model of laminar premixed flame propagation with assumed constant parameters was used to demonstrate the features of the suggested procedure. The suggested method allows finding optimal parameters for the defined functional dependence of the reaction rate on the temperature and reactant concentrations. The dependence of combustion adiabatic temperature on equivalence ratio is assumed to be known from the flame equilibrium calculations. The global kinetic parameters of combustion reaction were determined for methane, ethylene and propane mixtures with air on the basis of experimental data on burning velocity as function of the equivalence ratio. The calculated overall kinetic parameters are compared with parameters obtained by other methods within similar global model.


2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Rashiqah Rashli ◽  
Elmi Abu Bakar ◽  
Shahrul Kamaruddin

Ultrasonic welding had been widely used in various manufacturing industries such as aviation, medical, electronic device and many more. It offers a continued safe operation, faster and also low cost as it able to join weld part less than one second and also simple to maintain the tooling devices. Though ultrasonic welding brings a lot of advantages in assembly especially in thermoplastic material of manufacturing product, it also has a dominant problem to be deal with. The problem in ultrasonic welding is poor weld quality due to improper selection of ultrasonic welding parameters especially in near field configuration. Thus, an optimal combination of parameters is crucial in order to produce good quality weld assembly for this configuration. In this paper, ultrasonic welding process, ultrasonic weld joint defects and determination of optimal parameters for thermoplastic material had been discussed thoroughly. 


2016 ◽  
Author(s):  
Abdulaha-Al Baquy ◽  
Jiu-Yu Li ◽  
Chen-Yang Xu ◽  
Khalid Mehmood ◽  
Ren-Kou Xu

Abstract. Soil acidity has become a serious constraint in dry land crop production systems of acidic Ultisols in tropical and subtropical regions of southern China, where winter wheat and canola are cultivated as important rotational crops. Regardless of other common existing concerns in acidic Ultisols of southern China, it needs to be investigated whether soil acidity has any effect on wheat and canola growth. There is little information on the determination of critical soil pH as well as aluminium (Al) concentration for wheat and canola crops. The objective of this study was to determine the critical soil pH and exchangeable aluminium concentration (AlKCl) for wheat and canola production. Two pot cultures with two Ultisols from Hunan and Anhui were conducted for wheat and canola crops in a controlled growth chamber, with a completely randomized design. A soil pH gradient ranging from 3.7 (Hunan) and 3.97 (Anhui) to 6.5, with three replications, was used as a treatment. Aluminium sulfate (Al2(SO4)3) and hydrated lime (Ca(OH)2) were used to obtain the target soil pH levels. Plant height, shoot dry weight, root dry weight, and chlorophyll content (SPAD value) of wheat and canola were adversely affected by soil acidity in both locations. The critical soil pH and AlKCl of the Ultisol from Hunan for wheat were 5.29 and 0.56 cmol kg−1, respectively. At Anhui, the threshold soil pH and AlKCl for wheat were 4.66 and 2.36 cmol kg−1, respectively. On the other hand, the critical soil pH for canola was 5.65 and 4.87 for the Ultisols from Hunan and Anhui, respectively. The critical soil exchangeable Al for canola cannot be determined from the experiment of this study. The results suggested that the critical soil pH and AlKCl varied between different locations for the same variety of crop, due to the different soil types and their other soil chemical properties. The critical soil pH for canola was higher than that for wheat for both Ultisols, thus canola was more sensitive to soil acidity. Therefore, we recommend that liming should be undertaken to increase soil pH if it falls below these critical soil pH levels for wheat and canola production.


2021 ◽  
Vol 285 ◽  
pp. 02007
Author(s):  
Ivan Masienko ◽  
Sergey Shevchenko ◽  
Kirill Glytyan

The paper presents the determination of main parameters and operating modes of scattered centrifugal devices of technical units when using them in the technology with scattered sowing when performing the technological operation of sowing rice in liquid-flexible soil. Theoretical studies of the dependence of design features of the blade of a spreading disk on the number of blades installed on it and the radius of curvature of the end bend on the height of blades are carried out. The values of the diameter of the disk of a centrifugal dispenser and parameters of blades are set, which will increase the uniformity of distribution of seed material for a given width of a gripper and reduce its consumption.


This research is a study of the turning process by testing with brass material. There are three control factors: spindle of speed, feed rate, and depth of cut respectively. The turning process requires variable control,affect the quality of production productivity and production costplanning an experiment with the Taguchi Method help in theexperiment the analysis of variance, orthogonal array, and signal and noise ratios were considered as an experiment and survey of brass turning characteristics to determine the lowest material removal rate.The results obtained from the experiment were used to repeat the experiment for confirmation. This requires the turning process to be reliable and optimized


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