Search results

The purpose of this paper is to study the cause of severe corrosion of the galvanized lightning rods in a 220 kV transformer substation, and to seek the effective corrosion inhibition measures for the hollow lightning rods.

The corrosion morphology and rust component of lightning rod was analyzed, and the corrosion process of lightning rod was researched by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), ion chromatography and electrochemical tests.

The results indicated that the outer surface of hollow lightning rod was corroded slightly; however, its inner surface suffered severe corrosion because of a long time high-humidity environment inside the tube caused by the rainwater permeation. A rust layer consisted of Fe₃O₄ and a little FeOOH was accumulated on the inner surface of the hollow lightning rod. Moreover, Fe₃O₄ rust layer worked as a large cathode area which could promote the corrosion of metal substrate further. A self-accelerating corrosion process was formed on the inner surface, making the corrosion failure of lightning rod occurred and aggravated gradually.

The corrosion of inner surface of hollow lightning rod cannot be detected easily. More attention should be paid to the corrosion inhibition of lightning rod. The key of corrosion inhibition for the hollow lightning rod was to avoid the rainwater accumulation inside tube. The research results can provide guidelines on the corrosion inhibition measures selection of lightning rod in transformer substation.

For the climbing rod object with large diameter variation and the need of obstacle crossing, this paper aims to propose a new embracing-type climbing robot named as EVOC-I robot.

The design philosophy and structural scheme are introduced. The kinematic analysis of embracing and telescoping mechanisms is carried out to provide the theoretical foundation for the effective climbing of the robot. Based on the prototype robot, three preliminary experiments are carried out to verify the effectiveness of the designed robot.

The theoretical and experimental analyses have verified the reasonability and effectiveness of the proposed robot design.

As the preliminary study, the prototype still need a lot of improvement. The experimental verification is also limited. Future work will focus on improving the design and increasing the theoretical analysis, especially increasing experimental study and designing the next generation of the rod climbing robot.

The designed climbing robot can be used for climbing the rod with variation diameter and flange obstacle, especially the lightening rod in the transformer substation.

The paper designs a new climbing robot that integrates the ability of large variation diameter adaptation and obstacle crossing.

The paper aims to estimate the instantaneous breakdown voltage of the lightning discharge from simulated figures in an energized rod-plane configuration protected by a lightning rod. The same configuration of electrodes has been the subject of experimental investigations for the measurement of the instantaneous breakdown voltage using oscillographic monitoring. This study validates the simulation model by making a comparison with experimentation and involves the role of the inception field of the upward discharge in the propagation of this last one.

The research methodology is based on the development of a fractal lightning protection model based on real physical conditions of the discharge propagation, such as the downward discharge and the upward one emanating from protection. The voltage drop and the randomness character of the lightning discharge are also taken into account. The electrical field is an important parameter in discharge development; it is considered in this work at each step of the discharge propagation by the finite element method. The instantaneous breakdown voltage is measured and estimated by both empirical equations and simulated figures of lightning discharge

The established model that allows estimating the instantaneous breakdown voltage from simulated discharges and empirical equations gives results in a good agreement with experimentation. The involvement of the upward discharge inception field emanating from the lightning rod in the evolution of electrical discharge is illustrated.

The work presented in this paper aims to develop a new fractal lightning protection model taking into consideration physical phenomena intervening in the development of the lightning discharge.

The originality of this work consists of the combination between fractals modelling of the electrical discharge and the protection against lightning, in addition, to use one of the characteristics of the electrical discharge, which is the instantaneous breakdown voltage, to prove the importance of the inception field emanating from the upward discharge in the propagation criterion of this last one.

This paper aims to present a new approach to the numerical solution of skin effect integral equations in cylindrical conductors. An approximate, but very simple and accurate method for calculating the current density distribution, skin-effect resistance and inductance, in pulse regime of cylindrical conductor, having a circular or rectangular cross-section, is considered. The differential evolution method is applied for minimization of error functional. Because of its application in the practice, the lightning impulse is observed. Direct and inverse fast Fourier transform is applied.

This method contributes to increasing of correctness and much faster convergence. As the electromagnetic field components depend on the current density derivation, the proposed method gives a very accurate solution not only for current density distribution and resistance but also for field components and for internal inductance coefficients. Distribution of current and electromagnetic field in bus-bars can be successfully determined if the proximity effect is included together with the skin effect in calculations.

The study shows the strong influence of direct lightning strikes on the distribution of electrical current in cables used in lightning protection systems. The current impulse causes an increase in the current density at all points of the cross-section of the conductor, and in particular the skin effect on the external periphery. Based on the data calculated by using the proposed method, it is possible to calculate the minimum dimensions of the conductors to prevent system failures.

There are a number of approximations of lightning strike impulse in the literature. This is a limiting factor that affects the reliability and agreement between measured data with calculated values.

In contrast with other methods, the current density function is approximated by finite functional series, which automatically satisfy wave equation and existing boundary conditions. It is necessary to minimize the functional. This approach leads to a very accurate solution, even in the case when only two terms in current approximation are adopted.

The purpose of this paper is to emphasize the importance of anticipation rather than prediction in business strategy.

The paper takes the form of an opinion column.

This column attempts to demonstrate that supplementing standard strategy with a right‐brain, inductive examination of the basic working assumptions of the organization is the best way to anticipate catastrophe.

The paper presents an historic perspective on catastrophe and change that may be unavailable elsewhere.

Pay, tenure and promotion decisions are frequently based upon inferences regarding the value of faculty research. Meanwhile, departmental, college and university reputations are frequently based on perceptions regarding the quality of research being produced by its faculty. Making correct inferences requires accurate measurement of research quality, which is often based upon the journal through which results are shared. This research expands upon the research found elsewhere through its detailed investigation of leading journals in two business disciplines, including examination of four different citation-based measures and four journal characteristics which are exogenous to the quality of any individual piece of research. The paper aims to discuss this issue.

This study assists in the development of an accurate perspective regarding research quality, by studying the popular Journal Citation Reports (JCR) impact factor. A further expansion on the past literature is consideration of three newer journal quality metrics: SCImago Journal Rank (SJR), Source Normalized Impact per Paper (SNIP) and percentage of articles cited. Top-tier journals in finance and information systems are compared to evaluate the consistency of these measures across disciplines. Differences in journal characteristics and their impact on citation-rate based measures of quality are also examined. The potential impact of discipline-based variation in acceptance rate, issue frequency, the time since journal inception and total reviewers are put forth as additional potential exogenous factors that may impact the perception of journal quality. t-Tests are employed for discipline comparisons, while correlation and multiple regression are used for journal characteristic analysis.

There is a significant difference in the JCR impact measures of high-quality finance journals vs high-quality information systems journals, which are correlated with a variety of journal-specific factors including the journal’s acceptance rate and frequency of issue. Information systems journals domination of finance journals persists whether one considers mean, median, minimum or maximum impact factors. SJR measures for finance journals are consistently higher than information systems journals, though the SJR value of any individual journal can be quite volatile. By comparison, the SNIP metric rates premier information systems journals higher. Over 12 percent more of the articles in leading information systems journals are cited during the initial three years.

Logical extensions of this research include examining journals in other business disciplines. One could also evaluate quality measures reaction to variation in journal characteristics (i.e. changes in acceptance rates). Furthermore, one could include other measures of journal quality, including the recently released CiteScore metric. Such research will build on the present research and improve the accuracy of research quality assessment.

To the extent that citation-based research measures and journal-specific factors vary across disciplines as demonstrated by our investigation, discipline-specific traits should be considered adjusted for, when making inferences about the long-term value of recently published research. For instance, finance faculty publishing in journals with JCR readings of 2.0 are in journals that are 53 percent above the discipline’s average, while information systems faculty publishing in journals with JCR readings of 2.0 are in journals that are 18 percent below the discipline’s average. Furthermore, discipline-specific differences in journal characteristics, leading to differences in citation-based quality measures, should be considered when making inferences about the long-term value of recently published research in the process of making recommendations regarding salary adjustments, retention and promotion.

Quantity and quality of research are two hallmarks of leading research institutions. Assessing research quality is very problematic because its definition has changed from being based on review process (i.e. blind refereed), to acceptance rates, to impact factors. Furthermore, the impact factor construct has been a lightning rod of controversy as researchers, administrators and journals themselves argue over which metric to employ. This research is attempting to assess how impact factors and journal characteristics may influence the impact factors, and how these interactions vary business discipline. The research is especially important and relevant to the authors which separately chair departments including finance and information systems faculty, and therefore are in roles requiring assessment of faculty research productivity including quality.

This study is a detailed analysis of bibliographic aspects of the top-tier journals in two quantitative business areas. In addition to the popular JCR, SJR and SNIP measures of performance, the analysis studies the seldom-examined percentage of the article cited metric. A deeper understanding of citation-based measures is obtained though the evaluation of changes in how journals have been rated on these metrics over time. The research shows that there are discipline-related systematic differences in both citation-based research measures and journal-specific factors and that these discipline-specific traits should be considered when making inferences about the long-term value of recently published research. Furthermore, discipline-specific difference in journal characteristics, leading to differences in citation-based quality measures, should be considered when making personnel and remuneration decisions.

The purpose of this paper is to report research into the social defence of splitting and projection in schools. In splitting and projection, organisational members separate their unbearable feelings from the more acceptable ones and project them, typically towards other individuals and groups.

The research was undertaken in three secondary (11‐18), co‐educational, maintained schools in Wales, UK, using a case study method and a psychoanalytic approach and interpretive perspective. Data were collected during interviews and meetings with key players.

The cross‐case analysis and interpretation showed how features in the whole system such as institutional stress can create a setting in which splitting and projection may flourish. The inadequate definition and management of institutional roles may also contribute. Individuals and groups may act as “lightning rods” receiving and taking in projected feelings and may play a part in establishing themselves in that role. Splitting and projection can develop into blame, demonisation, scapegoating and bullying. The ability of those involved to transform projected feelings, that is, to accept them, contain them, change them into benign and acceptable forms, and then return them in that different form, is crucial to minimising the impact of splitting and projection and to ensuring that it does not grow into more dangerous organisational phenomena. This transformation‐and‐return process is a key educational leadership task.

The paper provides a new perspective on a widespread behaviour in schools and colleges and describes how the behaviour can be managed. It has implications for all educational leaders.

Over 3,000 scientists, technologists and industrialists attended the 1955 World Petroleum Congress, held in Rome, Italy, from June 6 to 17. Delegates representing 45 countries read papers covering all aspects of the petroleum industry, including geology and geophysics, drilling and production, oil processing, the production of chemicals from petroleum, the composition of petroleum, utilisation of petroleum products, and other more general subjects. Abstracts of papers included in the corrosion section are given below, and these discuss problems of graphite formation, the occlusion of hydrogen, static electricity, and corrosion inhibition in refinery equipment.

The purpose of this paper is to review the 1985-1991 project called “The Consumer Behavior Odyssey”, including a retrospective assessment of its context and role in influencing consumer research paradigms.

The study is based on personal recollections, introspective fieldnotes from the Odyssey and various publications and videos that emerged from the project. It also reflects on several subsequent “inside” and “outside” accounts of the project and its impact.

The paper concludes that the Odyssey was a critical event within a nexus of other critical events that helped precipitate what is now widely called Consumer Culture Theory. It was a highly visible project that acted as a lightning rod that attracted both supporters and opponents at the time, but that ultimately helped carve out a place for interpretive, qualitative, visual and ethnographic consumer research within business schools.

Although there were a number of methodological and research outputs from the Odyssey during the 1980s and early 1990s and there have been several recent “outside” appraisals of its influence since then, there has been only one subsequent “inside” account of its ontological and epistemological impact − a 2011 video made for the 50th anniversary of the major funding organization for the project, the Marketing Science Institute. This paper offers a more extensive appraisal by one of the project’s leaders.