kinetic characteristics
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2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Guang Jin ◽  
Shuai Ma ◽  
Zhenghui Li

This paper studies the kinematic dynamic simulation modeling of industrial robots in the Industry 4.0 environment and guides the kinematic dynamic simulation modeling of industrial robots in the Industry 4.0 environment in the context of the research. To address the problem that each parameter error has different degrees of influence on the end position error, a method is proposed to calculate the influence weight of each parameter error on the end position error based on the MD-H error model. The error model is established based on the MD-H method and the principle of differential transformation, and then the function of uniform variation of six joint angles with time t is constructed to ensure that each linkage geometric parameter is involved in the motion causing error accumulation. Through the analysis of the robot marking process, the inverse solution is optimized for multiple solutions, and a unique engineering solution is obtained. Linear interpolation, parabolic interpolation, polynomial interpolation, and spline curve interpolation are performed on the results after multisolution optimization in the joint angle, and the pros and cons of various interpolation results are analyzed. The trajectory planning and simulation of industrial robots in the Industry 4.0 environment are carried out by using a special toolbox. The advantages and disadvantages of the two planning methods are compared, and the joint space trajectory planning method is selected to study the planning of its third and fifth polynomials. The kinetic characteristics of the robot were simulated and tested by experimental methods, and the reliability of the simulation results of the kinetic characteristics was verified. The kinematic solutions of industrial robots and the results of multisolution optimization are simulated. The methods, theories, and strategies studied in this paper are slightly modified to provide theoretical and practical support for another dynamic simulation modeling of industrial robot kinematics with various geometries.


Author(s):  
Валерий Анатольевич Полухин ◽  
Римма Михайловна Белякова ◽  
Эльмира Джумшудовна Курбанова

Проведен анализ влияния Ti, Mo и W на характер аморфной нано- и кристаллической структуры на прочностные и кинетические характеристики - диффузии D и проницаемости Ф водорода в мембранных сплавах, созданных на основе бинарных Ni - Nb и V - Ni. Легирование сплавов Ni - V титаном, молибденом и вольфрамом ведет к постепенному замещению ими ниобия и ванадия и способствует образованию нескольких второстепенных фаз хотя и действующих как барьеры для диффузии водорода, но способствующих снижению процессов гидридообразования. Выявлена строгая зависимость кинетики водорода не только от термодинамических параметров -температуры и давления, но и от наличия свободного объема в формируемых аморфных, нано-кристаллических и кристаллических сплавов. Установлено, что процессы селективности, динамика водорода - его поток J, определяемый произведением диффузии и проницаемости (J = D×Ф), зависят от базового состава, выбора легирующих элементов (Ti,Mo и W ), а также формируемых структур - аморфной, нанокристаллической и полифазной дуплексной кристаллической микроструктурой. Установлено, что тщательно подобранный состав определяет производительность селективного процесса и способствует выделению высокочистого водорода с последующими его приложениями для зеленой энергетики. An analysis was carried out of influence of Ti, Mo and W on the nature of the amorphous nano- and crystalline structures on the strength and kinetic characteristics - diffusion D and permeability Ф of hydrogen in membrane alloys based on binary Nb - Ni, V - Ni. Doping with Nb - V alloys, titanium, molybdenum and tungsten leads to the gradual replacement of niobium and vanadium, and promotes the formation of several minor phases while acting as barriers for hydrogen diffusion, but contributing hydride reduction processes. A close dependence of the hydrogen kinetics was revealed not only on thermodynamic parameters - temperature and pressure, but also on the presence of free volume in the formed amorphous, nanocrystalline and crystalline alloys. So, the processes of selectivity, the dynamics of hydrogen - its flux J determined by the product of diffusion D and permeability Ф, J = D×Ф depend on the basic composition and the choice of alloying elements (Ti,Mo and W ), as well as the formed structures - amorphous, nanocrystalline and duplex, represented by multiphase crystalline microstructures. It was found that a carefully selected composition determines the productivity of the selective process and promotes the release of high-purity hydrogen with its subsequent applications for green energy.


2021 ◽  
Author(s):  
Xiyan Yang ◽  
Zihao Wang ◽  
Yahao Wu ◽  
Tianshou Zhou ◽  
Jiajun Zhang

While transcription occurs often in a bursty manner, various possible regulations can lead to complex promoter patterns such as promoter cycles, giving rise to an important issue: How do promoter kinetics shape transcriptional bursting kinetics? Here we introduce and analyze a general model of the promoter cycle consisting of multi-OFF states and multi-ON states, focusing on the effects of multi-ON mechanisms on transcriptional bursting kinetics. The derived analytical results indicate that bust size follows a mixed geometric distribution rather than a single geometric distribution assumed in previous studies, and ON and OFF times obey their own mixed exponential distributions. In addition, we find that the multi-ON mechanism can lead to bimodal burst-size distribution, antagonistic timing of ON and OFF, and diverse burst frequencies, each further contributing to cell-to-cell variability in the mRNA expression level. These results not only reveal essential features of transcriptional bursting kinetics patterns shaped by multi-state mechanisms but also can be used to the inferences of transcriptional bursting kinetics and promoter structure based on experimental data.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3286
Author(s):  
Alexander V. Rassolov ◽  
Igor S. Mashkovsky ◽  
Galina N. Baeva ◽  
Galina O. Bragina ◽  
Nadezhda S. Smirnova ◽  
...  

This research was focused on studying the performance of the Pd1Ag3/Al2O3 single-atom alloy (SAA) in the liquid-phase hydrogenation of di-substituted alkyne (1-phenyl-1-propyne), and development of a kinetic model adequately describing the reaction kinetic being also consistent with the reaction mechanism suggested for alkyne hydrogenation on SAA catalysts. Formation of the SAA structure on the surface of PdAg3 nanoparticles was confirmed by DRIFTS-CO, revealing the presence of single-atom Pd1 sites surrounded by Ag atoms (characteristic symmetrical band at 2046 cm−1) and almost complete absence of multiatomic Pdn surface sites (<0.2%). The catalyst demonstrated excellent selectivity in alkyne formation (95–97%), which is essentially independent of P(H2) and alkyne concentration. It is remarkable that selectivity remains almost constant upon variation of 1-phenyl-1-propyne (1-Ph-1-Pr) conversion from 5 to 95–98%, which indicates that a direct alkyne to alkane hydrogenation is negligible over Pd1Ag3 catalyst. The kinetics of 1-phenyl-1-propyne hydrogenation on Pd1Ag3/Al2O3 was adequately described by the Langmuir-Hinshelwood type of model developed on the basis of the reaction mechanism, which suggests competitive H2 and alkyne/alkene adsorption on single atom Pd1 centers surrounded by inactive Ag atoms. The model is capable to describe kinetic characteristics of 1-phenyl-1-propyne hydrogenation on SAA Pd1Ag3/Al2O3 catalyst with the excellent explanation degree (98.9%).


2021 ◽  
pp. 118275
Author(s):  
Tingrui Xu ◽  
Xuejiao Li ◽  
Na Li ◽  
Mengmeng Liu ◽  
Feng Wang ◽  
...  

Fuel ◽  
2021 ◽  
Vol 305 ◽  
pp. 121626
Author(s):  
Wei Lu ◽  
Jinhu Li ◽  
Jinliang Li ◽  
Qilin He ◽  
Wanshu Hao ◽  
...  

Author(s):  
И.К. Гиндулин ◽  
В.В. Юрченко

Изучение термодинамических и кинетических характеристик позволяет более эффек- тивно использовать углеродные адсорбенты в технологических процессах, чем поддерживается тех- нология их использования на оптимальном уровне. В работе изучалась адсорбционная активность углеродных нанопористых материалов, рассчитывались кинетические характеристики процесса ад- сорбции, термодинамические характеристики (энергия Гиббса, энтальпия, константа адсорбции) адсорбции ионов меди на активных углях, полученных на установках (модульная пиролизная реторт- ная установка) и УВП (углевыжигательная печь). Установлено, что процесс идёт самопроизвольно, характер адсорбционного взаимодействия экзотермический. Адсорбционные равновесие достигается меньше чем за 15 мин. The study of thermodynamic and kinetic characteristics allows more efficient use of carbon adsorbents in technological processes. Thus, keeping their use at an optimal level. The adsorption activity of carbon nanoporous materials was studied, the kinetic characteristics of the adsorption process, thermodynamic characteristics (Gibbs energy, enthalpy, adsorption constant) of copper adsorption on activated carbons obtained at MPRP and CK installations were calculated in this work. It was found that the process is spontaneous (G <0). The nature of the adsorption behavior is exothermic. Adsorption equilibrium is achieved in less than 15 minutes.


2021 ◽  
Vol 1 (7) ◽  
pp. 92-98
Author(s):  
Oleg G. Blinkov ◽  

Research objective is to work out a method of evaluating the performance of roller-cone drill bits by kinetic criteria. Introduction. It is difficult to determine the absolute criteria for the performance of rock cutting tools. Therefore, the relative values of wear resistance of the cutting structure of roller-cone bits and their relative mechanical rates of drilling are adopted as process criteria. Methods of research. The calculation and analysis of kinetic criteria for evaluating the performance of drill bits have significant differences. Taking them into account is important when studying various modifications of rock cutting tools. The set of kinetic criteria gives a picture of the relative performance of the bit using the model of the well bottom close to the real one. The set of kinetic characteristics (criteria) is conventionally called the kinetic datasheet of the drill bit. The key points of constructing an analytical model of the drill bit operation on the deformable well bottom have been considered. Scope of results. This technique provides for a comparative evaluation of roller-cone drill bits of various modifications, allows for finding feedback, i.e. searching for the appropriate combination of geometrical parameters of the rock cutting tool according to given kinetic characteristics. The versatile approach intended for use in the study of the performance of rock cutting tools allows the most complete and accurate evaluation of the influence of one factor or another on the final result.


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