Simplified analytical model to assess key factors influenced by fiber alignment and their effect on tensile performance of UHPC

Author(s):  
Le Teng ◽  
Huanghuang Huang ◽  
Kamal H. Khayat ◽  
Xiaojian Gao
2010 ◽  
Vol 29-32 ◽  
pp. 2350-2355
Author(s):  
Wei Liu ◽  
Ying Cao Zhou ◽  
Qing Zhao

The severe lateral vibration and impact of drill string will not only cause the damage of drill string but also have bad effects on the quality of directional drilling operation. It is difficult to control lateral vibration amplitude and impact intensity even with advanced measurement apparatus while drilling. So it is feasible to use a theoretic method to analyze and predict lateral vibration of drill string in order to adjust and optimize drilling parameters in real-time. On the basis of beam-column series and spring-concentrated mass model, a new analytical model is established to realize the control of lateral vibration and impact by controlling some key factors, such as under-gauge stabilizer, initial phase angle and initial deformation, WOB (weight on bit) and ROB (rotation of bit).


2020 ◽  
Vol 38 (6) ◽  
pp. 680-688 ◽  
Author(s):  
Jianyong Shi ◽  
Guohui Lei ◽  
Jingfeng Zhang ◽  
Yazhou Wei ◽  
Yu Ping Li ◽  
...  

It is a well appreciated fact that temperature is one of the key factors influencing the degradation of organics. Heat exchangers are a viable option that can be used to adjust the temperature in solid waste to an extent most suitable for waste degradation. This paper focuses on an experimental and theoretical investigation of the feasibility of using a water-circulating heat exchanger for thermal regulation of waste degradation. A cylindrical bioreactor with a central pipe connected to a water circulation system is devised and instrumented. The changes in temperature and gas production were monitored during the degradation of the organic component of the waste. Test results with and without thermal regulation are analyzed and compared. In addition, an analytical model is proposed to simulate the symmetrical heat transport behavior subjected to heat exchange. Heat generation due to the degradation of organics is taken into account. There was a good correlation between the analytical model prediction and the experimental data obtained from the laboratory test and field monitoring.


2019 ◽  
Vol 7 (7) ◽  
pp. 236
Author(s):  
Ou ◽  
Hu ◽  
Mao ◽  
Li

How to reduce the cogging torque of the integrated propeller motor is an important means to improve its noise performance because cogging torque is one of the key factors causing torque ripple. We proposed a method to reduce the cogging torque by optimizing the size of the Halbach array’s auxiliary pole. First, an analytical model for the airgap magnetic field of Halbach array based on different dimensions (including the circumference ratio and the radial thickness) of the auxiliary pole is given. Then the finite element method is used to verify the analytical model. On the basis, we calculated the cogging torque of different size of auxiliary poles as sample data by combining different circumference ratio and radial thickness. Furthermore, using the two-variable single-objective neural network genetic optimization algorithm based on Backpropagation (BP), we obtain the optimal size of the auxiliary pole. Finally, comparing the motor cogging torque and torque ripple before and after optimization indicated that the cogging torque and torque ripple are effectively reduced after optimizing the size of the auxiliary pole.


2014 ◽  
Vol 584-586 ◽  
pp. 2466-2475
Author(s):  
Dong Bing Huang ◽  
Qi Jun Li ◽  
Li Juan Shen

Construction cost risk management is an essential part of construction cost management,especially in the context of the ‘triple overrun’ that has been rampant across China over the last few years,i.e. the cost overrunning the budget,the budget overrunning the budgetary estimate, and the budgetary estimate overrunning the initial estimate. Since traditional methods of calculating construction reserve funds fail to serve the purpose of curbing the ‘triple overrun’,we deem it necessary to establish a quantitative, rational, and accurate calculation and analytical model to measure basic reserve funds. This paper aims to provide an analytical model based on the VaR technique, where parameters are determined by VaR’s three key factors, and a standard VaR process of analyzing basic reserve funds is set up. The model proves to be effective in our case study when basic reserve funds predicted by the model well match the actual ones,which is shown clearly by the Q-Q plot curves and CDF curves.


Author(s):  
Xiao Zhang

Polymer microscopy involves multiple imaging techniques. Speed, simplicity, and productivity are key factors in running an industrial polymer microscopy lab. In polymer science, the morphology of a multi-phase blend is often the link between process and properties. The extent to which the researcher can quantify the morphology determines the strength of the link. To aid the polymer microscopist in these tasks, digital imaging systems are becoming more prevalent. Advances in computers, digital imaging hardware and software, and network technologies have made it possible to implement digital imaging systems in industrial microscopy labs.


2019 ◽  
Vol 24 (5) ◽  
pp. 14-15
Author(s):  
Jay Blaisdell ◽  
James B. Talmage

Abstract Ratings for “non-specific chronic, or chronic reoccurring, back pain” are based on the diagnosis-based impairment method whereby an impairment class, usually representing a range of impairment values within a cell of a grid, is selected by diagnosis and “specific criteria” (key factors). Within the impairment class, the default impairment value then can be modified using non-key factors or “grade modifiers” such as functional history, physical examination, and clinical studies using the net adjustment formula. The diagnosis of “nonspecific chronic, or chronic reoccurring, back pain” can be rated in class 0 and 1; the former has a default value of 0%, and the latter has a default value of 2% before any modifications. The key concept here is that the physician believes that the patient is experiencing pain, yet there are no related objective findings, most notably radiculopathy as distinguished from “nonverifiable radicular complaints.” If the individual is found not to have radiculopathy and the medical record shows that the patient has never had clinically verifiable radiculopathy, then the diagnosis of “intervertebral disk herniation and/or AOMSI [alteration of motion segment integrity] cannot be used.” If the patient is asymptomatic at maximum medical improvement, then impairment Class 0 should be chosen, not Class 1; a final whole person impairment rating of 1% indicates incorrect use of the methodology.


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