scholarly journals Experimental Characterization of Polymer Surfaces Subject to Corona Discharges in Controlled Atmospheres

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1646 ◽  
Author(s):  
Leon-Garzon ◽  
Dotelli ◽  
Tommasini ◽  
Bianchi ◽  
Pirola ◽  
...  
Keyword(s):  
Polymethyl Methacrylate ◽  
Power Transmission ◽  
Polymer Surface ◽  
Operating Conditions ◽  
Polymer Surfaces ◽  
Corona Discharges ◽  
Structural Modifications ◽  
Controlled Atmospheres ◽  
Insulating Polymers ◽  
Polymeric Dielectrics

Polymeric dielectrics are employed extensively in the power transmission industry, thanks to their excellent properties; however, under normal operating conditions these materials tend to degrade and fail. In this study, samples of low-density polyethylene, polypropylene, polymethyl methacrylate, and polytetrafluorethylene were subjected to corona discharges under nitrogen and air atmospheres. The discharges introduced structural modifications over the polymer surface. From a chemical perspective, the alterations are analogous among the non-fluorinated polymers (i.e., polyethylene (PE), polypropylene (PP), and polymethyl methacrylate (PMMA)). A simulation of the corona discharge allowed the identification of highly reactive species in the proximity of the surface. The results are consistent with the degradation of insulating polymers in high-voltage applications due to internal partial discharges that ultimately lead to the breakdown of the material.

scholarly journals Powering Multiple Gas Condensate Wells in Russia’s Arctic: Power Supply Systems Based on Renewable Energy Sources

Resources ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 130
Author(s):  
Gennadiy Stroykov ◽  
Alexey Y. Cherepovitsyn ◽  
Elizaveta A. Iamshchikova
Keyword(s):  
Renewable Energy ◽  
Transmission Lines ◽  
Power Supply ◽  
Power Transmission ◽  
Renewable Energy Sources ◽  
Operating Conditions ◽  
Gas Condensate ◽  
The Arctic ◽  
Power Transmission Lines ◽  
Power Sources

Using renewable energy off-grid power supply and choosing the right equipment that meets the operating conditions in the Arctic can provide companies with reliable power sources for producing gas at facilities located in remote areas and will reduce capital and operating costs associated with the construction of power transmission lines. For more than 15 years, a remote control system powered by renewable energy has been used in parallel with power transmission lines by Gazprom to operate its multiwell pads in Russia’s Far North, which validates the relevance of this study. The subject of the study is a group of gas condensate wells that consists of four multiwell pads operated by Wintershall Russland GmbH. The article discusses a stand-alone renewable-based power system as an option for powering remote oil and gas production facilities. The procedures used in the study include calculating such parameters as power output and power consumption, choosing equipment, describing the design features of a power supply system for a multiwell pad, conducting an economic assessment of the project, comparing different power supply options, analyzing project risks, and developing measures to mitigate these risks.

scholarly journals Durable superoleophobic polypropylene surfaces

2016 ◽  
Vol 374 (2073) ◽  
pp. 20160193 ◽  
Author(s):  
Philip S. Brown ◽  
Bharat Bhushan
Keyword(s):  
High Temperature ◽  
Plastic Material ◽  
Polymer Surface ◽  
Polymer Surfaces ◽  
Surface Structures ◽  
Structured Surfaces ◽  
Mechanical Durability ◽  
Plastic Containers

Polypropylene (PP) is a popular plastic material used in consumer packaging. It would be desirable if such plastic containers were liquid repellent and not so easily fouled by their contents. Existing examples of superoleophobic surfaces typically rely on poorly adhered coatings or delicate surface structures, resulting in poor mechanical durability. Here, we report a facile method for creating superoleophobic PP surfaces via incorporation of nanoparticles (NPs) into the polymer surface. A solvent–NP–PP mixture was spin coated at high temperature to achieve the necessary roughness. Such surfaces were further functionalized with fluorosilane to result in a durable, super-repellent surface. They were also found to exhibit some repellency towards shampoos. This method of incorporating NPs into polymer surfaces could also prove useful in improving the anti-bacterial, mechanical and liquid-repellent properties of plastic devices. This article is part of the themed issue ‘Bioinspired hierarchically structured surfaces for green science’.

Tailored Polymer Surfaces

MRS Bulletin ◽  
1997 ◽  
Vol 22 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Anne M. Mayes ◽  
Sanat K. Kumar
Keyword(s):  
Statistical Mechanics ◽  
Chemical Modification ◽  
Surface Chemistry ◽  
First Principles ◽  
Surface Composition ◽  
Polymer Surface ◽  
Polymer Surfaces ◽  
Computing Power ◽  
Complex Chemical ◽  
Theoretical Approaches

The control of surface chemistry and topography has great technological relevance for numerous applications of polymers in textiles, adhesives, coatings, packaging, membranes, and biomedical implants. Conventionally, chemical modification of polymer surfaces has been achieved through kinetically governed practices that allow little control over the final surface composition or morphology. These chemically generated surfaces are also prone to reconstruction. Hence the development of inexpensive, scaleable routes to impart stable and more complex chemical functionality to polymer surfaces continues to be an active area of research. Apart from surface chemistry, the topography of a polymer surface often plays a determinant role in the adhesive, optical, and wetting characteristics of the surface. Consequently methods to produce surfaces of controlled texture are also of interest. Toward these goals, new, statistical, mechanics-based theoretical approaches, coupled with increased computing power, can now facilitate the first-principles design of polymer surfaces that are chemically and structurally “tailored” for a given application. In this article, we review some of the recent, significant developments in this area.

scholarly journals Quantitative Inference in a Mechanical Design “Compiler”

1989 ◽  
Author(s):  
A. C. Ward ◽  
W. P. Seering
Keyword(s):  
Design Process ◽  
Power Transmission ◽  
Mechanical Design ◽  
Operating Conditions ◽  
Optimal Selection ◽  
High Level Language ◽  
Hydraulic Power ◽  
Detailed Design ◽  
High Level ◽  
Selection Of

Abstract This paper introduces the theory underlying a computer program that takes as input a schematic of a mechanical or hydraulic power transmission system, plus specifications and a utility function, and returns catalog numbers from predefined catalogs for the optimal selection of components implementing the design. Unlike programs for designing single components or systems, this program provides the designer with a high level “language“ in which to compose new designs. It then performs much of the detailed design process. The process of “compilation”, or transformation from a high to a low level description, is based on a formalization of quantitative inferences about hierarchically organized sets of artifacts and operating conditions. This allows design compilation without the exhaustive enumeration of alternatives. The paper introduces the formalism, illustrating its use with examples. It then outlines some differences from previous work, and summarizes early tests and conclusions.

scholarly journals OPTIMAL POWER FLOW WITH TCSC DEVICE USING CUCKOO OPTIMIZATION ALGORITHM

2018 ◽  
Vol 54 (3A) ◽  
pp. 52
Author(s):  
Duong Thanh Long
Keyword(s):  
Power System ◽  
Optimization Algorithm ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Power Transmission ◽  
Optimization Techniques ◽  
Operating Conditions ◽  
Cuckoo Optimization Algorithm ◽  
Facts Devices ◽  
Optimal Power

Optimal Power Flow (OPF) problem is an optimization tool through which secure and economic operating conditions of power system is obtained. In recent years, Flexible AC Transmission System (FACTS) devices, have led to the development of controllers that provide controllability and flexibility for power transmission. Series FACTS devices such as Thyristor controlled series compensators (TCSC), with its ability to directly control the power flow can be very effective to power system security. Thus, integration TCSC in the OPF is one of important current problems and is a suitable method for better utilization of the existing system. This paper is applied Cuckoo Optimization Algorithm (COA) for the solution of the OPF problem of power system equipped with TCSC. The proposed approach has been examined and tested on the IEEE 30-bus system. The results presented in this paper demonstrate the potential of COA algorithm and show its effectiveness for solving the OPF problem with TCSC devices over the other evolutionary optimization techniques.

scholarly journals Methods for predicting the wear of contact inserts of electric rolling stock pantographs

2021 ◽  
Vol 258 ◽  
pp. 02032
Author(s):  
Victor Philippov ◽  
Oleg Sidorov ◽  
Elena Sidorova ◽  
Svetlana Podgornaya
Keyword(s):  
Service Life ◽  
Power Transmission ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Labor Costs ◽  
Contact Materials ◽  
High Speeds ◽  
Number Of Factors ◽  
Electric Rolling Stock

The use of current-collecting contact elements with an extended service life is one of the most economical and least costly ways to ensure reliable, economical and environmentally friendly power transmission to the rolling stock. To assess and predict the service life, Omsk State Transport University developed and successfully tested a methodology for conducting experimental studies of contact inserts for pantographs, including bench tests of each pair of contact materials. The obtained test results are the initial data for predicting the wear of elements of contact pairs and assessing their service life in real operating conditions. Prediction of wear and service life of contact elements is carried out using mathematical modeling of wear processes, taking into account the maximum possible number of factors that negatively affect the elements. The purpose of this article is to improve the method for predicting wear, taking into account high speeds. The use of a mathematical model in forecasting makes it possible to reduce time and labor costs by 2.5 - 3 times for conducting experimental studies and assessing the resource of an element of a contact pair.

scholarly journals A Multiobjective Optimization Analysis of Spur Gear Pair: The Profile Shift Factor Effect on Structure Design and Efficiency

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Samya Belarhzal ◽  
Kaoutar Daoudi ◽  
El Mostapha Boudi ◽  
Aziz Bachir ◽  
Samira Elmoumen
Keyword(s):  
Multiobjective Optimization ◽  
Power Transmission ◽  
Spur Gear ◽  
Shift Factor ◽  
Structure Design ◽  
Operating Conditions ◽  
Gear Pair ◽  
Contact Ratio ◽  
Face Width ◽  
Volume Equation

Spur gears are an indispensable element of power transmission, most of the time used in small environments with severe operating conditions such as high temperature, vibrations, and humidity. For this reason, manufacturers and transmission designers are required to look for better gear designs and higher efficiency. In this paper, a multiobjective optimization was conducted, using genetic algorithms (GAs) for corrected spur gear pair with an objective to reduce the structure volume and transmission power loss and reveal the influence of the profile shift factor on the optimal structure fitness. The optimization variables included are the pinion and wheel profile shift factors in addition to the module, face width, and the number of pinion teeth mostly used in standard gear optimization. The profile shift factor influences the shape of the gear teeth, the contact ratio, and the load sharing. It affects then the optimal results meaningfully. The gear pair volume, center distance, and efficiency presented the objective functions while contact stress, bending stress, face with coefficient, and tooth tip interferences served as constraints. Furthermore, a volume equation was developed, in which a bottom clearance formula is included for more accurate results. "Multiobjective optimization" is conducted at medium and high speeds, and the results show that the structure design is compact compared to standard gears with reasonable efficiency for medium contact ratio.

Nonlinear Resonance and Parametric Instability of a Power Transmission Belt: Numerical Analysis With Experiments

2001 ◽  
Author(s):  
Fabrizio Vestroni ◽  
Francesco Pellicano ◽  
Giulia Catellani ◽  
Annalisa Fregolent
Keyword(s):  
Numerical Analysis ◽  
Power Transmission ◽  
Damping Ratio ◽  
Parametric Instability ◽  
Nonlinear Resonance ◽  
Numerical Approach ◽  
Operating Conditions ◽  
High Dimensional ◽  
Response Curves ◽  
Parametric Resonances

Abstract In this paper a numerical approach is developed to forecast the dynamic behavior of a power transmission belt running on eccentric pulleys. Basic partial differential equations are developed, considering the elastic effect of the lower branch of the belt. Nonlinear resonances and dynamic instabilities are analyzed in detail using a high dimensional discrete model, obtained through the Galerkin procedure. The numerical analysis is performed by means of direct simulations and a continuation software. Numerical results are compared with available experimental data. It is shown that the numerical method is able to predict correctly the amplitudes of oscillation in several operating conditions: direct and parametric resonances. Frequency response curves are obtained when the belt is harmonically excited close to the first and second linear natural frequency. The damping ratio and the linear frequencies are identified at zero axial speed.

Utilization factor of adhesive weight of a locomotive with group tractive engine drive of wheelsets

2017 ◽  
pp. 267-279
Author(s):  
Victor Kruchek ◽  
Aleksander Grishenko ◽  
Tamila Tytova
Keyword(s):  
Mathematical Model ◽  
Power Transmission ◽  
Characteristic Curve ◽  
Practical Importance ◽  
Analytical Calculation ◽  
Operating Conditions ◽  
Railway Track ◽  
Movement Speed ◽  
Power Equipment ◽  
Utilization Factor

Objective: To improve accuracy of analytical calculation of adhesive weight of constructed and newly projected locomotives with wheelset group tractive drive. To bring out analytical dependence of a locomotive’s adhesive weight usage coefficient from a number of wheelsets in a group tractive engine considering constructive features of a vehicle, operating conditions and power equipment cycle of operation. Methods: Analytical dependences and a mathematical model were obtained on the basis of higher mathematics, laws of theoretical mechanics, reliability theory, probability theory, wheel-rail adhesion theory and the laws of self-excited frictional oscillations during slippage. Results: Mathematical model was developed to determine the highest value of a twisting moment, in the process of which occurs different slippage of a wheelset group tractive drive of a locomotive, taking into account the stochastic character of wheel-rail adhesion, shaking at the moment of starting and in the process of running. Characteristic curve of equalizing factor was plotted from a generalized parameter of a locomotive tractive drive. Practical importance: Analytical dependences make it possible to identify the right adhesive weight of a locomotive with wheelset group tractive drive for conducting traction calculations and the assessment of locomotive’s tractive capacity in the process of operation on different cycles of power equipment and movement speed. The level of dynamic load on group tractive drive components was determined, taking into account constructive features of trucks and power transmission, such as the jet thrust location of wheelset axial gear units, as well as maintenance conditions – movement speed and irregularities of a railway track. The results of the study may be applied in projecting the new and constructed locomotives.

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