scholarly journals Study of Factors Determinant of Siliceous Electrical Porcelain Resistance to Structural Degradation

2016 ◽  
Vol 61 (3) ◽  
pp. 1489-1496
Author(s):  
P. Ranachowski ◽  
Z. Ranachowski ◽  
S. Kudela ◽  
A. Pawełek ◽  
A. Piątkowski
Keyword(s):  
Low Voltage ◽  
Operating Conditions ◽  
Electrical Porcelain ◽  
Ageing Process ◽  
Material Structure ◽  
Structural Factors ◽  
Structural Degradation ◽  
Degradation Processes ◽  
Decisive Influence ◽  
The Subject

Abstract The subject of this study was investigation of the factors that have a decisive influence on the resistance of siliceous porcelain to degradation processes. There was tested material C 110 type, which is widely used for the production of low-voltage (LV) elements such as insulators and bushings. On the basis of mechanical-acoustic and microscopic research of small-sized samples, which were subjected to compression, there were distinguished successive stages of degradation of the material structure. In the authors’ opinion, they have a reference to the ageing process, taking place during many years of work under operating conditions. Thus, it was possible to assess the structural factors that determine the durability and reliability of LV electroinsulating elements. The results were related to electrical aluminous porcelains.

The Economic Theory of the Firm: A Generalization

2012 ◽  
pp. 41-66 ◽  
Author(s):  
M. Storchevoy
Keyword(s):  
Economic Theory ◽  
General Theory ◽  
Contract Theory ◽  
Theory Of The Firm ◽  
Material Structure ◽  
Structural Factors ◽  
Boundaries Of The Firm ◽  
Opportunistic Behaviour ◽  
New Variant

The paper deals with development of a general theory of the firm. It discusses the demand for such a theory, reviews existing approaches to its generalization, and offers a new variant of general theory of the firm based on the contract theory. The theory is based on minimization of opportunistic behaviour determined by the material structure of production (a classification of ten structural factors is offered). This framework is applied to the analysis of three boundaries problems (boundaries of the job, boundaries of the unit, boundaries of the firm) and five integration dilemmas (vertical, horizontal, functional, related, and conglomerate).

Renovating the View of Cost Sharing for the Underground Low Voltage Cable Projects in Hanoi

2019 ◽  
Vol 35 (5E) ◽  
Author(s):  
Pham Thi Thu Ha ◽  
Phan Dieu Huong
Keyword(s):  
Willingness To Pay ◽  
Cost Sharing ◽  
Low Voltage ◽  
Power Grid ◽  
Field Studies ◽  
Power Industry ◽  
Well Field ◽  
The Subject ◽  
Sharing Responsibility ◽  
The Cost

Underground power grid projects in Hanoi is so urgent that it requires immediate implementation. To synchronously and quickly implement the underground power grid projects, people in charge should not follow the outdated perspectives of just including the power industry, but also need to call for the support and cost sharing responsibility from consumers. This paper aims at approaching the subject both from the producers and consumers’ perspectives to together sharing the cost of putting the power grid underground not only in Hanoi but other metropolitans in Vietnam as well. Field studies (including 104 families) at Hoan Kiem District, Hanoi and CBA method were applied to investigate the willingness to pay (WTP) level of consumers to share the cost with the power industry for the underground power grid projects in Hanoi. The overview of the results shows that cost for the underground power grid in Hoan Kiem District ranging from 30,000 VND/household/month to 46,000VND/household/month. On the other hand, the willingness to pay of a typical household of four people within Hoan Kiem District ranges from 17,000VND/month to 24,000VND/month, with the most favorable method of annual payment within a detailed timeline.

scholarly journals A Novel Hybrid LDC Converter Topology for the Integrated On-Board Charger of Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3603
Author(s):  
Vu-Hai Nam ◽  
Duong-Van Tinh ◽  
Woojin Choi
Keyword(s):  
Low Voltage ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Battery Charger ◽  
Forward Converter ◽  
Vehicle To Grid ◽  
Circulating Current ◽  
In Series ◽  
Converter Topology ◽  
Output Capacitor

Recently, the integrated On-Board Charger (OBC) combining an OBC converter with a Low-Voltage DC/DC Converter (LDC) has been considered to reduce the size, weight and cost of DC-DC converters in the EV system. This paper proposes a new integrated OBC converter with V2G (Vehicle-to-Grid) and auxiliary battery charge functions. In the proposed integrated OBC converter, the OBC converter is composed of a bidirectional full-bridge converter with an active clamp circuit and a hybrid LDC converter with a Phase-Shift Full-Bridge (PSFB) converter and a forward converter. ZVS for all primary switches and nearly ZCS for the lagging switches can be achieved for all the operating conditions. In the secondary side of the proposed LDC converter, an additional circuit composed of a capacitor and two diodes is employed to clamp the oscillation voltage across rectifier diodes and to eliminate the circulating current. Since the output capacitor of the forward converter is connected in series with the output capacitor of the auxiliary battery charger, the energy from the propulsion battery can be delivered to the auxiliary battery during the freewheeling interval and it helps reduce the current ripple of the output inductor, leading to a smaller volume of the output inductor. A 1 kW prototype converter is implemented to verify the performance of the proposed topology. The maximum efficiency of the proposed converter achieved by the experiments is 96%.

Perlite in the production of low-voltage electrical porcelain

1967 ◽  
Vol 24 (2) ◽  
pp. 93-94
Author(s):  
I. G. Khizanishvili ◽  
A. A. Aizenberg
Keyword(s):  
Low Voltage ◽  
Electrical Porcelain

Application of Moving Car Observer Method for Measuring Free Flow Speed on Two-lane Highways

2014 ◽  
Vol 69 (6) ◽  
Author(s):  
Othman Che Puan ◽  
Muttaka Na’iya Ibrahim ◽  
Usman Tasiu Abdurrahman
Keyword(s):  
Field Measurement ◽  
Flow Speed ◽  
Operating Conditions ◽  
Free Flow ◽  
Geometric Features ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Free Flow Speed ◽  
The Subject ◽  
Low Traffic

There exists a need to evaluate the performance indicator that reflects the current level of service (LOS) of the subject facility to justify any decision making on expenditures to be made for improving the performance level of a road facility. Free-flow speed (FFS) is one of the key parameters associated with LOS assessment for two-lane highways. Application of a more realistic approach for assessing road’s performance indicators would result in better estimates which could in turn suggest the most appropriate decision to be made (for situations where upgrading is needed); especially, in terms of finance, materials and human resources. FFS is the driver’s desired speed at low traffic volume condition and in the absence of traffic control devices. Its estimation is significant in the analysis of two-lane highways through which average travel speed (ATS); an LOS indicator for the subject road class is determined. The Highway Capacity Manual (HCM) 2010 offers an indirect method for field estimation of FSS based on the highway operating conditions in terms of base-free-flow-speed (BFFS). It is however, recommended by the same manual that direct field FSS measurement approach is most preferred. The Malaysian Highway Capacity Manual (MHCM) established a model for estimating FFS based on BFFS, the geometric features of the highway and proportion of motorcycles in the traffic stream. Estimating FFS based on BFFS is regarded as an indirect approach which is only resorted to, if direct field measurement proved difficult or not feasible. This paper presents the application of moving car observer (MCO) method for direct field measurement of FFS. Data for the study were collected on six segments of two-lane highways with varying geometric features. FFS estimates from MCO method were compared with those based on MHCM model. Findings from the study revealed that FFS values from MCO method seem to be consistently lower than those based on MHCM model. To ascertain the extent of the difference between the FFS values from the two approaches, student t-statistics was used. The t-statistics revealed a P–value of less than 0.05 (P < 0.05) which implies that there is a statistically significant difference between the two sets of data. Since MCO method was conducted under low traffic flow (most desired condition for field observation), it can be suggested that MCO estimates of FFS represent the actual scenario. A relationship was therefore developed between the estimates from the two methods. Thus, if the MHCM model is to be applied, the measured value needs to be adjusted based on the relationship developed between the two approaches.

scholarly journals The Dependence of Selected Technical and Combustion Characteristics of Fire on Moisture Levels in Alternative Fuels

2014 ◽  
Vol 9 (1) ◽  
pp. 25-30
Author(s):  
Martin Kulich
Keyword(s):  
Alternative Fuels ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Final Part ◽  
Operational Risks ◽  
Operational Safety ◽  
The Subject

Abstract The subject of this paper is to analyse the influence of moisture on selected technical and combustion characteristics of alternative fuels. The analyses are conducted on the basis of analyses of samples of alternative fuels simulating states of the fuel in expected operating conditions, focusing on the identification of potential operational risks. The final part consists of a set of recommended measures to ensure the operational safety of the practical use of alternative fuels based on the results of the analysis.

scholarly journals Midlife - Maturity and Creativity

2019 ◽  
Vol 12 (2) ◽  
pp. 143-149
Author(s):  
Valeria Egidi Morpurgo
Keyword(s):  
Severe Trauma ◽  
Ageing Process ◽  
Collective Trauma ◽  
Generational Transmission ◽  
The Subject ◽  
Process Loss ◽  
Specific Difficulty ◽  
Mass Murders ◽  
Development Of Tolerance ◽  
Mourning Process

Abstract Midlife is an age of crisis according to many authors, as it sets the subject up against the inevitability of the ageing process, loss, and the limitedness of life. Most authors view midlife as an age of crisis where everything can be staked back into the game. But some other authors have highlighted how midlife is characterised by a new burst of creativity, by new object investments and by a redressing of the balance between narcissism (which decreases) and object investments for which a larger share of the libido becomes available. The Author thinks that it seems worthwhile to make a distinction between midlife, as indicative of a phase of life, and maturity, construed as a psychic position which is relatively independent of age. Therefore, she explores the creativity area of the trans-generational transmission, quoting some psychoanalysts and poets, and introducing a clinical example of the mourning process for losses inherent in the passing of time and the development of tolerance capacities to deal with a change in the balance between the libido and narcissism. Then the Author affords a specific difficulty in transmitting a trans-generational mandate, when the treatment concerns cases of severe trauma, like victims of collective trauma and mass murders. What can be transmitted in these cases if the psychological concatenation between the generations is interrupted and breaks down? How can it be linked up again? The story and re-elaboration by Henri Parens is brought as an example to be studied and commented.

scholarly journals Algorithms and models of power losses in circuit breakers installed in networks

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (4) ◽  
pp. 345-353
Author(s):  
E. I. Gracheva ◽  
A. N. Gorlov ◽  
A. N. Alimova
Keyword(s):  
Power Supply ◽  
Low Voltage ◽  
Technical Condition ◽  
Active Power ◽  
Operating Conditions ◽  
Public Utility ◽  
Electrical Networks ◽  
Power Losses ◽  
Circuit Breakers ◽  
Technical Parameters

Determination of the main characteristics of the topology and technical condition of equipment underoperating conditions is necessary for analyzing and assessing power and electricity losses in intrashoplow-voltage industrial power supply networks. A comparative analysis of the technical characteristicsof automatic circuit breakers VA57-31 (KEAZ), NSX100 TM-D (Schneider Electric), DPX3 160 (Legrand), Tmax XT1 TMD (ABB) has shown that the main technical parameters of the machines are close in their values. At that it has been found out that automatic switches of the BA57-31 series have the lowest value of power losses per pole (7.5 W), whereas the automatic switches of the Tmax XT1 TMD series have the highest value (10 W). Thus, under the operating conditions of the equipment, the lowest value of power and electricity losses is characteristic of low-voltage electrical networks with installed circuit breakers of the BA57-31 series, and the highest value of losses is noted in in-shop systems with installed circuit breakers Tmax XT1 TMD. Using catalog data, the dependences of active power losses in circuit breakers on rated currents have been established; the algorithms have been developed and the obtained dependences have been modeled using approximating functions. The standard deviation of the compiled approximating functions has been calculated. Analytical expressions of the dynamics of power losses per pole have been determined as a function of the rated current. The graphical dependences of the investigated parameters of low-voltage equipment have been presented. The developed models are recommended to be used to increase the reliability of the assessment and refinement of the amount of active power and electricity losses in low-voltage electrical networks of industrial power supply systems, agrotechnical complexes, and enterprises of the public utility sector.

Resistance of Polymer Dispersion Additive Modified Concrete to Light Liquids Action

2014 ◽  
Vol 941-944 ◽  
pp. 730-733 ◽  
Author(s):  
Maciej Gruszczyński
Keyword(s):  
Concrete Strength ◽  
Polymer Concrete ◽  
Material Structure ◽  
Reinforced Concrete Structures ◽  
Polymer Dispersion ◽  
Petrol Station ◽  
Concrete Properties ◽  
Different Types ◽  
The Subject ◽  
Styrene Butadiene

Numerous concrete and reinforced concrete structures (industrial floors, petrol station or manoeuvring park pavements, elements of sewage system) are subjected to danger of permanent or periodical action of petroleum liquids that often causes the considerable reduction in concrete strength as well as decrease of bond between concrete and steel, which usually results in structure damages. The subject of the paper is estimation of influence of polymer dispersion additive (styrene-acrylic co-polymer and styrene-butadiene latex) onto durability of concrete subjected to action of different types of light liquids. The influence of polymer dispersion additive was confronted with the action of silica fume usually applied for sealing the structure of concrete. In the paper there are presented tests results for different types of light liquids onto such cement-polymer concrete properties as: strength, penetration depth of light liquids into material structure.

Hypermedia Programs for Mechanical Engineering

1994 ◽  
Author(s):  
Timothy K. Hight ◽  
Lee E. Hornberger ◽  
Elizabeth Lawrence ◽  
Matthew W. Gawlowski
Keyword(s):  
Engineering Students ◽  
New Technology ◽  
Technical Information ◽  
Operating Conditions ◽  
Machine Design ◽  
Standard Type ◽  
Stage Of Development ◽  
The Subject ◽  
Information Transmittal ◽  
Accessible Form

Abstract Engineers need to absorb and learn large amounts of new technical information. Effective methods of receiving this information are needed. Hypermedia stacks are one emerging avenue for information transmittal. This paper discusses two programs that have been created to address two distinct requirements for information transmittal — description of new technology in an easily accessible form, and guiding novices in developing skills and gaining insights in solving a particular type of problem. The first program was developed using a HyperCard stack and a Macintosh computer and describes current techniques available for rapid prototyping. Professional engineers and engineering students are largely unaware of these technologies because information on the subject is new. The second program is being developed using ToolBook under Windows and deals with the problem of sizing an idler shaft under given loads and operating conditions. This is a standard type of problem that might be given in a junior level machine design course. It draws on knowledge from statics and strength of materials and so acts as a review of fundamentals as well as a test of deeper understanding. This second program is at an earlier stage of development.

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