Over the past several years, several bushings equipped with draw leads have failed in service. These bushings are not isolated to a single manufacturer and all of them have passed standardroutine and type tests. A co...
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Over the past several years, several bushings equipped with draw leads have failed in service. These bushings are not isolated to a single manufacturer and all of them have passed standardroutine and type tests. A common characteristic of each failure is the arcing marks found between the draw lead cable and the tube in the center of the bushing. Most of the bushings also failed violently, in that the bushing exploded and caused a fire. The purpose of this panel session paper is four fold: First, extensive investigations have already been conducted on aspects of certain failure mechanisms, and the findings will be reported. Second, other possible, but as yet uninvestigated, failure modes are given. Third, it is hoped this report will draw the interest of others in the industry who will add to the knowledge surrounding this subject. Fourth, suggestions are made to prevent or alleviate the problem. It is not known exactly what causes the arcing in the first place, but it is currently thought that it is initiated by a transient of some kind then is sustained by the power frequency service voltage. Possible transient generators and the ensuing failure mechanism are described.
Pure poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and zinc oxide (ZnO)/PHBV composite nanofibers were fabricated by an electrospinning *** nanoparticles (NPs) with a diameter of about 10-20 nm were doped in the...
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Pure poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and zinc oxide (ZnO)/PHBV composite nanofibers were fabricated by an electrospinning *** nanoparticles (NPs) with a diameter of about 10-20 nm were doped in the PHBV fibers and no dispersion agent was *** pure PHBV and composite electrospun fibers were smooth and *** NPs did not affect the basic crystalline structure of electrospun PHBV fibers.
Polymer-nanoinorganic particles composite membranes present an interesting approach for improving the physical and chemical,as well as separation properties of polymer membranes,because they possess character-istics o...
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Polymer-nanoinorganic particles composite membranes present an interesting approach for improving the physical and chemical,as well as separation properties of polymer membranes,because they possess character-istics of both organic and inorganic membranes such as good permeability,selectivity,mechanical strength,ther-mal stability and so *** preparations and structures of polymer-nanoinorganic particles composite membranes and their unique properties are reviewed.
A Hybrid Pneumatic Power System (HPPS) has been developed for several years with the major aim of reducing the vehicle fuel consumption, environment pollution and enhancing the vehicle performance as well. Comparing w...
A Hybrid Pneumatic Power System (HPPS) has been developed for several years with the major aim of reducing the vehicle fuel consumption, environment pollution and enhancing the vehicle performance as well. Comparing with the conventional hybrid system, HPPS replaces the battery′s electrochemical energy with a high-pressure air storage tank and enables the internal combustion engine (ICE) to function at its sweet spot. Besides, the HPPS, which effectively merges both the high-pressure air flow from the storage tank and the recycled exhaust flow from the ICE, thereby increases the thermal efficiency of the ICE and transforms the merged flow energy into mechanical energy using a high-efficiency turbine. This paper focuses on the majorresearch process into HPPSs, including overall dynamic simulation and experimental validation. By using the simulation tool ITI-Sim, this research demonstrates an experiment which can be operated precisely according to the requirements of various driving conditions under which a car actually runs on the road in accordance with the regulatedrunning vehicle test mode. HPPS is expected to increase the performance of the entire system from 15% to 39%, and is likely to replace the traditional system in the coming years.
This paper presents a method for generating optimal command profiles for linear time-invariant mechanical systems with model *** generation for such systems should satisfy multiple conditions and constraints such as i...
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This paper presents a method for generating optimal command profiles for linear time-invariant mechanical systems with model *** generation for such systems should satisfy multiple conditions and constraints such as initial and final conditions,actuator limits,andresidual vibration suppression after the *** had previously proposed a novel command-generation method forrelatively simple dynamic systems and verified the method using single input *** the proposed method,the control input is represented as a linear superposition of triangle waves,and the problem is formulated as a linear programming *** this study,the proposed method is applied to more general linear time-invariant mechanical systems and verified using some benchmark problems,including a multi-input case.
The lattice parameters, band structure, density of state and elastic constant of rE-doped CeO2 (rE=Sm, Gd, dy), the buffer material for coated HTS conductors, are calculated using the plane-wave method with pseudopote...
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The lattice parameters, band structure, density of state and elastic constant of rE-doped CeO2 (rE=Sm, Gd, dy), the buffer material for coated HTS conductors, are calculated using the plane-wave method with pseudopotentials based on the density functional theory (dFT) of first-principle. The rule and mechanism of the effect of rare earth impurity on the critical thickness of the CeO2 buffer layer are investigated. It is found that, in the range of the calculation, the changes of the lattice volume V and elastic constant E of CeO2 with the impurity are mainly determined by the increased electrons ne of the system. The relationship of the elastic constant E and increased electrons ne is established. It is indicated that the critical thickness of the CeO2 single buffer layerdoped with Sm, Gd, anddy may be enhanced by 22%, 43% and 33%, respectively.
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