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Search Results: 1 - 10 of 120149 matches for " Hongbing Wang "
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Finite Element Analysis on a Square Canister Piezoelectric Energy Harvester in Asphalt Pavement  [PDF]
Hongbing Wang, Chunhua Sun
World Journal of Engineering and Technology (WJET) , 2016, DOI: 10.4236/wjet.2016.42035
Abstract: A novel square canister piezoelectric energy harvester was proposed for harvesting energy from asphalt pavement. The square of the harvester was of great advantage to compose the harvester array for harvesting energy from the asphalt pavement in a large scale. The open circuit voltage of the harvester was obtained by the piezoelectric constant d33 of the piezoelectric ceramic. The harvester is different from the cymbal harvester which works by the piezoelectric constant d31. The finite element model of the single harvester was constructed. The open circuit voltage increased with increase of the outer load. The finite element model of the single harvester buried in the asphalt pavement was built. The open circuit voltage, the deformation difference percent and the stress of the ceramic of the harvester were obtained with different buried depth. The open circuit voltage decreased when the buried depth was increased. The proper buried depth of the harvester should be selected as 30 - 50 mm. The effects of structure parameters on the open circuit voltage were gotten. The output voltage about 64.442 V could be obtained from a single harvester buried under 40 mm pavement at the vehicle load of 0.7 MPa. 0.047 mJ electric energy could be gotten in the harvester. The output power was about 0.705 mW at 15 Hz vehicle load frequency.
Finite Element Analysis and Test of an Ultrasonic Compound Horn  [PDF]
Hongbing Wang, Chunhua Sun
World Journal of Engineering and Technology (WJET) , 2017, DOI: 10.4236/wjet.2017.53029
Abstract: An?ultrasonic compound horn is designed and manufactured, and the horn is analyzed by wave equation, finite element method and test. The modal frequencies and frequencies of the first and second longitudinal vibration of the horn are obtained by the finite element analysis. The horn is made and modal testing is carried out. The modal frequencies of the first and second longitudinal vibration are obtained respectively. The test results are in good agreement with the theoretical calculation. Experimental results show the maximum amplitude of the horn can reach 9?nm with applied excitation voltage of amplitude 7?V and frequency 21,450?Hz, when the amplitude of voltage increases?to 80?V, the horn of maximum amplitude reaches?23 μm. The maximum amplitude of the horn is approximately proportional to the amplitude of excitation voltage. The horn has the characteristics of high sensitivity and large amplitude, and can be used in ultrasonic machining and other fields.
Research Status and Development Direction of Piezoelectric Wind Energy Harvesting Technology  [PDF]
Hongbing Wang, Chunhua Sun
Journal of Power and Energy Engineering (JPEE) , 2019, DOI: 10.4236/jpee.2019.73001
Abstract: In recent years, with the rapid development of large-scale distributed wireless sensor systems and micro-power devices, the disadvantages of traditional chemical battery power supply mode are becoming more and more obvious. Piezoelectric energy collector has attracted wide attention because of its simple structure, no heating, no electromagnetic interference, environmental protection and easy miniaturization. Wind energy is a reproducible resource. Wind energy harvester based on piezoelectric intelligent material can be named piezoelectric wind energy harvesting which converts wind energy into electric power and will have great application prospect. To promote the development of piezoelectric wind energy harvesting technology, research statuses on piezoelectric wind energy harvesting technology are reviewed. The existing problem and development direction about piezoelectric wind energy harvester in the future are discussed. The study will be helpful for researchers engaged in piezoelectric wind energy harvesting.
On Piezoelectric Energy Harvesting from Human Motion  [PDF]
Chunhua Sun, Guangqing Shang, Hongbing Wang
Journal of Power and Energy Engineering (JPEE) , 2019, DOI: 10.4236/jpee.2019.71008
Abstract: With the rapid development of low-power communication technology and microelectronics technology, wearable and portable embedded health monitoring devices, micro-sensors, and human body network positioning devices have begun to appear. For seeking reliable energy sources to replace battery on these devices, it is of great significance for developing low power products to explore the research of piezoelectric effect in conversion of human motion into electricity. Based on the different human motions, the existing technology of piezoelectric energy harvester (PEH) is firstly classified, including PEHs through heel-strike, knee-joint, arm motion, center of mass. The technology is then summarized and the direction of future development and efforts is further pointed out.
Review of cigarette smoking and tuberculosis in China: intervention is needed for smoking cessation among tuberculosis patients
Jianming Wang, Hongbing Shen
BMC Public Health , 2009, DOI: 10.1186/1471-2458-9-292
Abstract: An observational study was conducted in two rural areas of China. A total of 613 TB patients frequency matched with 1226 controls were interviewed by using a structured questionnaire. The associations between cigarette smoking and risk of TB were estimated by computing odds ratios (ORs) and 95% confidence intervals (95% CIs) from logistic regression model. Patients' smoking behavior and patterns of smoking cessation were followed after TB diagnosis. Multivariate Cox proportional hazards model was applied to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) in analyzing the risk factors for smoking relapse. The Kaplan-Meier estimate was computed to plot the ability of smoking-free after cessation among different groups, with the Log-rank test being used to compare the difference.The proportion of cigarette smoking was 54.6% in TB cases, which was significantly higher than that in controls (45.1%) with adjusted OR of 1.93(95% CI: 1.51–2.48). Though 54.9% smokers stopped smoking after being diagnosed with TB, more than 18% relapsed during the follow-up period. The proportion of relapse was higher within 6–9 months (6%) and 12–15 months (11%) after cessation. In the Cox regression estimates adjusted for age and gender, compared with those highly educated and previously treated patients, the hazard ratios of smoking relapse were 3.48(95% CI: 1.28–9.47) for less educated (< 6 years) and 4.30(95% CI: 1.01–18.30) for newly treated patients, respectively.Cigarette smoking is associated with TB in the Chinese. Interventions of smoking cessation are recommended to be included in the current TB control practice.Tuberculosis (TB) is one of the leading causes of death in the world and remains a major public health burden in many developing countries [1]. From worldwide epidemic of TB in 2006, around 9.2 million new cases and 1.7 million deaths were expected every year, of which 0.7 million cases and 0.2 million deaths were in HIV-positive people [2].As a risk f
Modeling of Fuel Elements Cycling System in Pebble Bed Reactor Based on Timed Places Control Petri Nets  [PDF]
Hongbing Liu, Peng Shen, Dong Du, Xin Wang, Haiquan Zhang
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B098
Abstract:

Pebble bed reactors use cycling scheme of spherical fuel elements relying on fuel elements cycling system (FECS). The structure and control logic of FECS are very complex. Each control link has strict requirements on time and sequence. This increases the difficulties of description and analysis. In this paper, timed places control Petri nets (TPCPN) is applied for the modeling of FECS. On this basis the simulation of two important processes, namely uploading fuel elements into the core for the first time and emptying the core is finished by simulation software Arena. The results show that as TPCPN is able to describe different kinds of logic relationship and has time properties and control properties, it’s very suitable for the modeling and analysis of FECS.

Finite Element Analysis of Vehicle Load Effect on Harvesting Energy Properties of a Piezoelectric Unit  [PDF]
Chunhua Sun, Hongbing Wang, Jie Liu, Guangqing Shang
Energy and Power Engineering (EPE) , 2015, DOI: 10.4236/epe.2015.710047
Abstract: To realize the goal of harvesting energy from pavement vibration on a large scale, a new type of piezoelectric harvesting units as the energy transducer has been proposed. The piezoelectric harvesting units are paved 40 mm below the asphalt, which is the same as thickness of the top layer of typical asphalt pavement in China. The spacing distance is 2200 mm, which is the same as the one between two tires of a normal vehicle. A mathematical model of the unit is deduced on Meda empirical formula and Hamilton principle and piezoelectric equations. Effects of the external vehicle load on its harvesting energy properties and pavement deformation and stress are analyzed with the finite element method. The results show that the excited voltage is linearly variation with contact pressure while the harvested electrical energy exponential varies with contact pressure. The more the contact pressure is, the larger the harvested electrical energy and the deformation and stress are. The harvested electrical energy also increases with the load frequency. At least 100 mJ of electrical energy can be collected with the proposed piezoelectric harvesting unit. It shows that the technology application of the piezoelectric harvesting energy from pavement is promising.
Parameters Optimization for Piezoelectric Harvesting Energy from Pavement Based on Taguchi’s Orthogonal Experiment Design  [PDF]
Chunhua Sun, Hongbing Wang, Guangqing Shang, Jianhong Du
World Journal of Engineering and Technology (WJET) , 2015, DOI: 10.4236/wjet.2015.34016
Abstract: To effectively harvest vibration energy from pavement without affecting driving comfort and safety, parameter optimization was done with the orthogonal experiment design and the finite element analysis. L16(44) Taguchi’s orthogonal experiments were carried out with planted depth, PZT material, PZT diameter and thickness as optimization parameters and with open voltage and pavement displacement as optimization objectives. The experiment results were obtained via the finite element method. By using range analysis method, the dominance degree of the influencing factors and the optimum condition was obtained for the two objectives, respectively. Further, the multi-objective optimization was performed based on a weight grade method. The combined optimum conditions in order of their dominance degree are PZT diameter 35 mm, PZT thickness 6 mm, planted depth 50 mm and material PZT4. The validity of optimization scheme was confirmed.
Deep removal of 4,6-dimethyldibenzothiophene from model transportation diesel fuels over reactive adsorbent
Wang, Shengqiang;Wang, Ruicong;Yu, Hongbing;
Brazilian Journal of Chemical Engineering , 2012, DOI: 10.1590/S0104-66322012000200021
Abstract: this paper presents a new reactive adsorbent used to effectively remove 4,6-dimethyldibenzothiophene (4,6-dmdbt) from model transportation diesel fuels. this reactive adsorbent was composed of formaldehyde, phosphotungstic acid and mesoporous silica gel. the experiment was based on an assumed condensation reaction of 4,6-dmdbt with formaldehyde using phosphotungstic acid as catalyst in pore spaces. the effect of temperature and the amount of formaldehyde and phosphotungstic acid loaded on the substrate were investigated in a batch system. in the breakthrough experiment, three different model diesel fuels containing 1000 mg/kg 4,6-dmdbt were pumped through a fixed-bed reactor packed with reactive adsorbent at constant temperature and atmospheric pressure, respectively. the experimental results showed that sulfur-free model fuel was obtained at 80oc despite the presence of aromatics. the sulfur capacity of regenerated reactive adsorbent was almost totally recovered.
The Brief Research on the Pitch Pattern Comparison of Electroacoustic Disguised Voice  [PDF]
Hongbing Zhang
Open Journal of Acoustics (OJA) , 2013, DOI: 10.4236/oja.2013.32006
Abstract: Camouflage voice is the common check material form in judicial voice testing field that brings about many difficulties to speaker identification. Aiming at the electroacoustic disguised voice, we get fundamental frequency variation rule before and after voice change of multiple corpuses by analyzing map and data. The results show that the fundamental frequency before and after voice change exists a linearity relationship, we can realize speaker identification in electroacoustic disguised speech field through comparing Chinese pitch pattern.
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