scholarly journals Synchronization and Stability of a Three Co-Rotating Rotor System Coupled with Springs in a Non-Resonance System

2021 ◽  
pp. 580-598
Author(s):  
Mingjun Du ◽  
Yongjun Hou ◽  
Tong Tang ◽  
Lian Tang ◽  
Jialong Wang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Phase Synchronization ◽  
Drilling Fluid ◽  
Electromagnetic Coupling ◽  
Rapid Development ◽  
Research Result ◽  
Electrical Coupling ◽  
High Capacity ◽  
Rotor System ◽  
Horizontal Drilling

With the rapid development of horizontal drilling technology, the drilling fluid shale shaker (DFSS) features high capacity and high efficiency. Hence, a vibrating mechanism of a three co-rotating rotor system coupled with springs is proposed for designing large-sized and heavy-duty vibrating screens in petroleum drilling engineering. To master synchronization of the vibrating system, the dynamic equations of three corotating rotors coupled with springs are first developed based on Lagrange’s equations. Second, synchronous conditions of the system are derived based on the average method, and its stability criterion is obtained by adopting Hamilton’s principle. Furthermore, the influences of various factors, including positional parameters of three motors, stiffness coefficient of the springs and frequency ratio on synchronization behaviour, are numerically analysed in the steady state. Additionally, the Runge–Kutta algorithm with adaptive control is employed to build an electromagnetic coupling model, and the relationships between the synchronization state of the system and its mechanical-electrical coupling characteristics are investigated. Finally, an experimental prototype is designed to validate the theory and numerical analysis. The research result shows that the in-phase synchronization of three co-rotating rotors coupled with springs is easy to implement with the selection of a sufficiently large stiffness.

scholarly journals A Multi-Loop Vehicle-Counting Method under Gray Mode and RGB Mode

2021 ◽  
Vol 11 (15) ◽  
pp. 6831
Author(s):  
Yue Chen ◽  
Jian Lu
Keyword(s):  
Intelligent Transportation Systems ◽  
High Efficiency ◽  
Road Traffic ◽  
Low Cost ◽  
Rapid Development ◽  
Intelligent Transportation ◽  
Transportation Systems ◽  
Counting Method ◽  
Moving Vehicle ◽  
Available Information

With the rapid development of road traffic, real-time vehicle counting is very important in the construction of intelligent transportation systems (ITSs). Compared with traditional technologies, the video-based method for vehicle counting shows great importance and huge advantages in its low cost, high efficiency, and flexibility. However, many methods find difficulty in balancing the accuracy and complexity of the algorithm. For example, compared with traditional and simple methods, deep learning methods may achieve higher precision, but they also greatly increase the complexity of the algorithm. In addition to that, most of the methods only work under one mode of color, which is a waste of available information. Considering the above, a multi-loop vehicle-counting method under gray mode and RGB mode was proposed in this paper. Under gray and RGB modes, the moving vehicle can be detected more completely; with the help of multiple loops, vehicle counting could better deal with different influencing factors, such as driving behavior, traffic environment, shooting angle, etc. The experimental results show that the proposed method is able to count vehicles with more than 98.5% accuracy while dealing with different road scenes.

scholarly journals Regional Zenith Tropospheric Delay Modeling Based on Least Squares Support Vector Machine Using GNSS and ERA5 Data

2021 ◽  
Vol 13 (5) ◽  
pp. 1004
Author(s):  
Song Li ◽  
Tianhe Xu ◽  
Nan Jiang ◽  
Honglei Yang ◽  
Shuaimin Wang ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Least Squares ◽  
High Efficiency ◽  
Rapid Development ◽  
Support Vector ◽  
Tropospheric Delay ◽  
Improvement Rate ◽  
Zenith Tropospheric Delay ◽  
Background Data ◽  
Mean Square Errors

The meteorological reanalysis data has been widely applied to derive zenith tropospheric delay (ZTD) with a high spatial and temporal resolution. With the rapid development of artificial intelligence, machine learning also begins as a high-efficiency tool to be employed in modeling and predicting ZTD. In this paper, we develop three new regional ZTD models based on the least squares support vector machine (LSSVM), using both the International GNSS Service (IGS)-ZTD products and European Centre for Medium-Range Weather Forecasts Reanalysis 5 (ERA5) data over Europe throughout 2018. Among them, the ERA5 data is extended to ERA5S-ZTD and ERA5P-ZTD as the background data by the model method and integral method, respectively. Depending on different background data, three schemes are designed to construct ZTD models based on the LSSVM algorithm, including the without background data, with the ERA5S-ZTD, and with the ERA5P-ZTD. To investigate the advantage and feasibility of the proposed ZTD models, we evaluate the accuracy of two background data and three schemes by segmental comparison with the IGS-ZTD of 85 IGS stations in Europe. The results show that the overall average Root Mean Square Errors (RMSE) value of all sites is 30.1 mm for the ERA5S-ZTD, and 10.7 mm for the ERA5P-ZTD. The overall average RMSE is 25.8 mm, 22.9 mm, and 9 mm for the three schemes, respectively. Moreover, the overall improvement rate is 19.1% and 1.6% for the ZTD model with ERA5S-ZTD and ERA5P-ZTD, respectively. In order to explore the reason of the lower improvement for the ZTD model with ERA5P-ZTD, the loop verification is performed by estimating the ZTD values of each available IGS station. In actuality, the monthly improvement rate of estimated ZTD is positive for most stations, and the biggest improvement rate can even reach about 40%. The negative rate mainly comes from specific stations, these stations are located on the edge of the region, near the coast, as well as the lower similarity between the individual verified station and training stations.

High Efficiency Combined Aggregate – Submerged Combustion Melter–Electric Furnace for Vitrification of High-Level Radioactive Wastes

2004 ◽  
Author(s):  
L. S. Pioro ◽  
I. L. Pioro
Keyword(s):  
Electric Furnace ◽  
High Efficiency ◽  
High Capacity ◽  
Main Idea ◽  
Melting Process ◽  
Radioactive Wastes ◽  
Single Stage ◽  
Interface Surface ◽  
High Level ◽  
Submerged Combustion

It is well known that high-level radioactive wastes (HLRAW) are usually vitrified inside electric furnaces. Disadvantages of electric furnaces are their low melting capacity and restrictions on charge preparation. Therefore, a new concept for a high efficiency combined aggregate – submerged combustion melter (SCM)–electric furnace was developed for vitrification of HLRAW. The main idea of this concept is to use the SCM as the primary high-capacity melting unit with direct melt drainage into an electric furnace. The SCM employs a single-stage method for vitrification of HLRAW. The method includes concentration (evaporation), calcination, and vitrification of HLRAW in a single-stage process inside a melting chamber of the SCM. Specific to the melting process is the use of a gas-air or gas-oxygen-air mixture with direct combustion inside a melt. Located inside the melt are high-temperature zones with increased reactivity of the gas phase, the existence of a developed interface surface, and intensive mixing, leading to intensification of the charge melting and vitrification process. The electric furnace clarifies molten glass, thus preparing the high-quality melt for subsequent melt pouring into containers for final storage.

scholarly journals Development of COVID-19 vaccines utilizing gene therapy technology

2021 ◽  
Author(s):  
Hironori Nakagami
Keyword(s):  
Viral Vectors ◽  
High Efficiency ◽  
Genetic Disorders ◽  
Rapid Development ◽  
Adenovirus Vector ◽  
Phase 3 ◽  
Double Blind ◽  
Time Period ◽  
Short Period ◽  
Long Time

Abstract There is currently an outbreak of respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronavirus disease 2019 (COVID-19) is caused by infection with SARS-CoV-2. Individuals with COVID-19 have symptoms that are usually asymptomatic or mild in most initial cases. However, in some cases, moderate and severe symptoms have been observed with pneumonia. Many companies are developing COVID-19 vaccine candidates using different technologies that are classified into four groups (intact target viruses, proteins, viral vectors and nucleic acids). For rapid development, RNA vaccines and adenovirus vector vaccines have been urgently approved, and their injection has already started across the world. These types of vaccine technologies have been developed over more than 20 years using translational research for use against cancer or diseases caused by genetic disorders but the COVID-19 vaccines are the first licensed drugs to prevent infectious diseases using RNA vaccine technology. Although these vaccines are highly effective in preventing COVID-19 for a short period, safety and efficiency evaluations should be continuously monitored over a long time period. As the time of writing, more than 10 projects are now in phase 3 to evaluate the prevention of infection in double-blind studies. Hopefully, several projects may be approved to ensure high-efficiency and safe vaccines.

scholarly journals Achieving Atomic Dispersion of Highly Loaded Transition Metals in Small‐Pore Zeolite SSZ‐13: High‐Capacity and High‐Efficiency Low‐Temperature CO and Passive NO x Adsorbers

2018 ◽  
Vol 57 (51) ◽  
pp. 16672-16677 ◽  
Author(s):  
Konstantin Khivantsev ◽  
Nicholas R. Jaegers ◽  
Libor Kovarik ◽  
Jonathan C. Hanson ◽  
Franklin (Feng) Tao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Transition Metals ◽  
High Efficiency ◽  
High Capacity ◽  
Small Pore ◽  
Highly Loaded

Robust, high-efficiency, high-capacity cryogenic trap

1991 ◽  
Vol 63 (11) ◽  
pp. 1182-1184 ◽  
Author(s):  
Carl A. M. Brenninkmeijer
Keyword(s):  
High Efficiency ◽  
High Capacity

Research of Android Platform Application Based on HTML5

2014 ◽  
Vol 651-653 ◽  
pp. 1901-1904
Author(s):  
Xian Wei Li
Keyword(s):  
Data Storage ◽  
Computer Technology ◽  
High Efficiency ◽  
Rapid Development ◽  
Management Information ◽  
Development Environment ◽  
Android Platform ◽  
User Data ◽  
Realization Process ◽  
Application Module

In the society with the rapid development and popularization of computer technology, the management information system has become the hot field of software development. It runs stably in the browsers, like IE6, IE7, IE8, IE9 and FireFox, with high efficiency, sound security, friendly interface and simple operation. It has done research on the design and realization process of HTML5 off-line data storage on the Android platform. Under the Eclipse integrated development environment, with Android SDK and HTML5 grammar, develop the system, which realize the functions of off-line storage, addition, deletion and modification of user data. It enables the application of HTML5 of Android platform and has made detailed analysis on the Android platform and HTML5 application module. The result indicates, the webpage application design of HTML5 conducted on the Android platform, is simple and fast, which can better meet the demand of Android cellphone users.

A Study on the Control of Residual Stress of Copper Thick-Film Using 2D Nanomaterial

2021 ◽  
Vol 21 (12) ◽  
pp. 5960-5964
Author(s):  
Kwon Jai Lee ◽  
Jee Young Oh ◽  
Kyong Nam Kim
Keyword(s):  
Residual Stress ◽  
Heat Dissipation ◽  
High Efficiency ◽  
Rapid Development ◽  
Electronic Devices ◽  
Copper Film ◽  
Electronics Industry ◽  
Electronic Components ◽  
Graphene Layers ◽  
Electronic Parts

With the rapid development of the electronics industry, high-density electronic devices and component mounting have gained popularity. Because of the heat generated from these devices, efficiency of the electronic parts is significantly lowered and life of various electronic devices is considerably shortened. Therefore, it is essential to efficiently dissipate the heat generated from the device to extend product life and ensure high efficiency of electronic components. This study evaluated how residual stress is impacted by the thickness of the deposited copper film, which is widely used as a heat dissipation material, and the number of graphene layers. The results confirmed that the residual stress decreased with increasing thickness. Moreover, the residual stress changed based on the transfer area of graphene, which had an elastic modulus eight times that of copper, indicating that the residual stress of the deposited copper film can be controlled.

Steady-State Characteristics of a Dual-Rotor System With Intershaft Bearing Subjected to Mass Unbalance and Base Motions

2018 ◽  
Author(s):  
Xi Chen ◽  
Mingfu Liao
Keyword(s):  
Steady State ◽  
High Efficiency ◽  
Equations Of Motion ◽  
Axial Rotation ◽  
Rotor System ◽  
Mode Shapes ◽  
Mass Unbalance ◽  
Moving Base ◽  
Lateral Rotation ◽  
Force Vectors

A dual-rotor system with an intershaft bearing subjected to mass unbalance and base motions is established. Using Lagrange’s principle, equations of motion for dual-rotor system relative to moving base are derived. Rotary inertia, gyroscopic inertia, transverse shear deformation, mass unbalance, and six components of deterministic base motions are taken into account. Using state-space vector, steady-state characteristics of dual-rotor system are analyzed through dual-rotor critical speed map, mode shapes, unbalance responses considering base rotations, frequency responses due to base motions, and shaft orbits. The results show that base translations just add external force vectors, while base rotations bring on parametric system matrices and additional force vectors. Base rotations not only change natural frequencies of dual-rotor system, but also break the symmetry of dynamic characteristics in the case of base lateral rotation. Excited by base harmonic translation, resonant frequencies correspond to whirl frequencies. The orbit remains circular under base axial rotation, while it becomes elliptical with a static offset under lateral rotation and then a complicated curve due to harmonic translation. When harmonic frequency of base translation gets close to dual-rotor excitation frequencies, obvious beat vibration appears. Overrall, this flexible approach can ensure calculation accuracy with high efficiency and good expandability.

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