Diagnosis of Inter-Turn Short Circuit for a Polyphase Induction Motor in Closed-Loop Vector-Controlled Drives

The main objective of this paper is to develop and experimentally verify a new technique to detect an inter-turn short circuit in one phase of a stator winding of an induction motor energized from a vector-controlled drive. This is in order to overcome the fault masking difficulties associated with the concept of depending on the actual magnetic field pendulous oscillation between the conventional voltage and current space vectors with respect to a reference that is unaltered by the compensation action of the drive. This technique is based on the flux pendulous oscillation phenomenon. This flux pendulous oscillation is also described in this paper, this in addition to the magnetic field pendulous oscillation previously addressed in prior publications. The new approach has been verified through experimental results which are represented here

Participatory variety selection and scaling: Small grain cereals

United States Agency for International Developmen

HAPS Gateway Link in the 5850-7075 MHz and Coexistence with Fixed Satellite Service

Gateway link is essential to connect HAPS platform to terrestrial based networks. This crucial link is incorporated in HAPS fixed service spectrum allocation in considerably high frequencies, renders the link for more attenuations by atmospheric gases, and rain effects, especially when the regional climate is not favorable. However, under the agenda item 1.20 of World Radio Conference-2012 (WRC-12) new HAPS allocation in the 5850-7075 MHz band is proposed. Although, spectrum features are incomparably reliable, on the contrary, Fixed Satellite Service (FSS) uplink transmissions will have signal levels much higher than those in HAPS systems and have the potential for causing interference at the HAPS gateway receiver. In this article a key aspect of co-channel interference phenomena is investigated to facilitate optimum frequency sharing in the band in question. By proposing mitigation techniques and statistical method this generic prediction model enhances the capability of the HAPS spectrum sharing and provides flexibility in spectrum planning for different fixed services

The role of caspases in Parkinson’s Disease pathogenesis: a brief look at the mitochondrial pathway

Parkinson’s disease (PD) is a neurodegenerative disorder characterised by tremor, rigidity, Bradykinesia and reduced facial expression. Development of PD is considered to be the result of deficiency of the neurotransmitter dopamine, which is due to death of Dopamine-Containing Neurons (DCNs) that produce dopamine in the pars compacta region of the substantia nigra. Although the concentrated efforts of the scientific community over the last decades, the etiology of the death of DCN is yet to be understood. Oxidative stress has been considered as one of the causes of defects in the mitochondria leading to the dopaminergic cell damage [1]. Levodopa therapy is a well-known treatment for the symptoms of PD, however long term use of L-dopa causes side effects including further enhancement of oxidative stress [2]. The elevated levels of Reactive Oxidative Species (ROS) such as hydrogen peroxide, superoxide and hydroxyl ions, induce stimulation to the Permeability Transition Pore (mPTP) of the mitochondria leading to the collapse of the mitochondrial membrane potential and the release of cytochrome C. Furthermore, increased ROS activity promote nitric oxide binding to superoxide producing peroxynitrate enhancing oxidative and nitrosative stress, which results in DNA damage, chromosomal mutations, lipid peroxidation and enzyme defects [3]. Mutation of E3 ligase caused by peroxynitrate damage leads to impairment of ubiquitin-proteasome system, resulting in high levels of defective proteins, which accumulate in the Endoplasmic Reticulum (ER) promoting ER stress and ultimately cell death. Moreover, the apoptotic neuron triggers injury signals that activate microglia and promote release of cytokines such as interleukins-6 and -8. Subsequently, interleukins trigger Caspase activation along with inducible NO synthase, which further elevates formation of nitric oxide. Exposure to excessive reactive nitrite species along with enhanced production of ROS and peroxynitrate lead to dysfunction of complex-IV and complex-I activities of the mitochondria and promote mitochondrialmediated apoptosis through Caspase activation [4,5]

A requirements engineering framework for integrated systems development for the construction industry

Computer Integrated Construction (CIC) systems are computer environments through which collaborative working can be undertaken. Although many CIC systems have been developed to demonstrate the communication and collaboration within the construction projects, the uptake of CICs by the industry is still inadequate. This is mainly due to the fact that research methodologies of the CIC development projects are incomplete to bridge the technology transfer gap. Therefore, defining comprehensive methodologies for the development of these systems and their effective implementation on real construction projects is vital. Requirements Engineering (RE) can contribute to the effective uptake of these systems because it drives the systems development for the targeted audience. This paper proposes a requirements engineering approach for industry driven CIC systems development. While some CIC systems are investigated to build a broad and deep contextual knowledge in the area, the EU funded research project, DIVERCITY (Distributed Virtual Workspace for Enhancing Communication within the Construction Industry), is analysed as the main case study project because its requirements engineering approach has the potential to determine a framework for the adaptation of requirements engineering in order to contribute towards the uptake of CIC systems

Crash Analysis and Energy Absorption Characteristics of S-shaped Longitudinal Members

This paper presents finite element simulations of the crash behavior and the energy absorption characteristics of thin S-shaped longitudinal members with variable cross-sections made of different materials to investigate the design of optimized energy-absorbing members. Numerical studies are carried out by simulation via the explicit finite element code LS-DYNA [1] to determine the desired variables for the design of energy-absorbing members. The specific energy absorption (SEA), the weight of the members and the peak force responses during the frontal impact are the main measurements of the S-shaped members' performance. Several types of inner stiffening members are also investigated to determine the influence of the additional stiffness on the crash behavior

Corporate Governance Disclosure Quality: Signalling Theory Insights and a Related UK-Egypt Empirical Analysis and Evaluation

The essential background of this research lies in the domain of corporate governance (CG). The importance of CG comes fundamentally from its attempt to minimise the conflict of interest between the principal and the agent and consequently, decrease the information asymmetry through corporate disclosures. Disclosures made to, and for, the public by a corporation are corporate disclosures. Corporations disclose through regulated financial reports, including financial statements, footnotes, management discussion and analysis, and other regulatory filings. Using Signalling Theory as the theoretical framework, this research examines the effect of three sets of characteristics, namely company characteristics set (stock exchange index, S&P ESG (Standard & Poor's Environmental, Social, and Governance) index, company age, company size, type of auditor, cross-listing, profitability, liquidity, ownership structure, and foreign institutional investors), CG characteristics set (Chief Executive Officer (CEO) duality, Board of Directors (BoD) size, BoD independence, and Audit Committee), and country-specific characteristics set (country) on the Corporate Governance Disclosure (CGD) quality within the context of the U.K. and Egyptian listed companies. The U.K. companies are selected from the population of listed companies on the London Stock Exchange (LSE) under the Financial Times Stock Exchange (FTSE) 100 index. Regarding the sample of the Egyptian companies, it is based on listed companies on the Egyptian Exchange (EGX) EGX100 EWI index. The final testable sample comprised 65 U.K. listed companies and 70 Egyptian listed companies over the period of three years 2019-2021 across six business sectors. The dependent variable CGD quality is a numeric computed variable. For each company, its CGD score is developed using the 52 (financial and non-financial) disclosure items as identified within the 2011 United Nations Conference on Trade and Development (UNCTAD) International Standards of Accounting and Reporting (ISAR) benchmark. The Content Analysis and Evaluation Approach is used to quantify CGD quality for each company. A series of statistical analyses are conducted including correlation, multiple regression, analysis of variance, and T-test. The correlation results for the U.K. sample reveal that only three variables emerged to be highly statistically significant and positively correlated with the CGD quality. These are the variables of company size, BoD size, and BoD independence. However, company age, profitability, liquidity, and ownership structure appear to have no significant correlation with CGD quality. Regarding the Egyptian sample, the correlation results are slightly different. The CGD quality is highly statistically significant and positively correlated with the company size, profitability, ownership structure, and BoD size. On the other hand, the CGD quality is positively correlated and statistically significant with BoD independence. However, while the relationship between the CGD quality and the company age emerges to be highly statistically significant, it is curiously, negatively correlated. Moreover, liquidity (while negatively correlated) appears to have no significant correlation with the CGD quality. In terms of the U.K. and Egyptian samples, both samples reveal that the CGD quality appears to be positively correlated and highly statistically significant with the company size and BoD size. Furthermore, the BoD independence is revealed to be positively correlated with the CGD quality for both samples. however, in the U.K., it was highly statistically significant, while in Egypt, it was statistically significant. Equally, both samples reveal that liquidity appears to have no significant correlation with CGD quality. In terms of the multiple regression results themselves, the research determines that the independent variables, combining company characteristics and CG characteristics as well as the country variable, explain 88.87% of the change in the CGD quality, based on the R-squared %. The results indicate that CGD quality increases with S&P ESG index listing, larger company size, auditor with Big 4 affiliation, being cross-listed, higher profitability, higher liquidity, higher free float percentage, larger BoD size, and higher BoD independence; (2) decreases in older companies, with the existence of foreign institutional investors, with CEO duality, and in companies located in Egypt. Regarding the business sectors, there were two tests employed to explore the differences within and between the six identified business sectors as follows: Analysis of variance and T-test. Regarding the analysis of variance, the results suggested that there is a statistically significant difference in CGD Quality across the six identified business sectors in the U.K. as well as the six identified business sectors in Egypt. As for the T-test, the results indicate that there is a statistically significant difference between the average score of CGD quality in companies in the U.K. compared to Egypt. The U.K. companies have an average CGD quality score higher than the Egyptian companies across all the six identified business sectors. Generally, the results of the research support the theoretical arguments that companies tend to adopt higher CGD quality in order to reduce information asymmetry and, eventually, increase investors' trust. The empirical evidence from this research contributes to knowledge in respect to CGD quality and contributes to policy recommendations for the directors of the companies, investors, and regulators. More importantly, it contributes to the CGD practices in Egypt, one of the developing countries where the financial regulators and professional bodies work hard to improve CGD quality

The Response of Karachi Stock Exchange to Nuclear Detonation

Stock markets are highly reactive to internal and external developments. News of major events take no time to impact, the Stock Exchange that quite often serves as a barometer of the good and bad for the market. The importance of particular events and their effect on the stock market has been a subject of study in financial literature. Such studies attempt to assess the extent to which stock markets’ performance stray’s from the normal around the time of the occurrence of subject events. The stock market crash in the USA of October 1987 and related crash in the Far East later in January 1998 led to several studies of the event. On October 14, 1987, the US stock market began the steepest decline of its history, culminating in the crash of October 19, when the Dow Jones Industrial Average fell 508 points (22.6 percent). Certain aspects of the event of Black Monday as it is called emphasised the need for research to explore what fundamental economic factors triggered the large decline and the institutional and structural factors that were inherent in the trading strategies of investors. Michell and Netter (1989) have presented evidence that a tax bill containing anti takeover provision proposed by the U.S. House Ways and Means Committee of Oct. 13, 1987 was the economic event that triggered the October 19 crash. Other events and economic conditions during October 14–16 have been cited in the literature including higher than expected trade deficits, rising interest rate and increased worries about the government deficit and fear of inflation by many studies. Certain trading strategies such as index arbitrage and portfolio insurance has been cited by the Report of Presidential Task Force (1988). Roll (1988) has argued the crash did not begin in US since many other world markets experienced a severe decline on October 19 before US markets opened.