Advanced control and optimisation of DC-DC converters with application to low carbon technologies

Prompted by a desire to minimise losses between power sources and loads, the aim of this Thesis is to develop novel maximum power point tracking (MPPT) algorithms to allow for efficient power conversion within low carbon technologies. Such technologies include: thermoelectric generators (TEG), photovoltaic (PV) systems, fuel cells (FC) systems, wind turbines etc. MPPT can be efficiently achieved using extremum seeking control (ESC) also known as perturbation based extremum seeking control. The basic idea of an ESC is to search for an extrema in a closed loop fashion requiring only a minimum of a priori knowledge of the plant or system or a cost function. In recognition of problems that accompany ESC, such as limit cycles, convergence speed, and inability to search for global maximum in the presence local maxima this Thesis proposes novel schemes based on extensions of ESC. The first proposed scheme is a variance based switching extremum seeking control (VBS-ESC), which reduces the amplitude of the limit cycle oscillations. The second scheme proposed is a state dependent parameter extremum seeking control (SDP-ESC), which allows the exponential decay of the perturbation signal. Both the VBS-ESC and the SDP-ESC are universal adaptive control schemes that can be applied in the aforementioned systems. Both are suitable for local maxima search. The global maximum search scheme proposed in this Thesis is based on extensions of the SDP-ESC. Convergence to the global maximum is achieved by the use of a searching window mechanism which is capable of scanning all available maxima within operating range. The ability of the proposed scheme to converge to the global maximum is demonstrated through various examples. Through both simulation and experimental studies the benefit of the SDP-ESC has been consistently demonstrated

Shareholder activism in Malaysia: exploring a missing parameter

The topic of shareholder activism has become an important issue for discussion in the corporate world, and debate continues to exist with regard to this matter. In the corporate world, the minority shareholders are the least protected corporate participants, due to their minimal voice in corporate decision-making. This paper is not empirically based but merely conceptual. Therefore, it is aimed at presenting the preliminary work for a study. The concepts of corporate governance, ownership structure and control, shareholder-companies relationship and majority-minority shareholders relationship are discussed, in order to gain an understanding of the concept and some practical perspectives of shareholder activism. From the discussion, several missing parameters of shareholder activism were derived. These missing parameters are considered red flags; there is a dire need to conduct further research for a better understanding of this important topic

Sustainable Development: An Analytical Vision for Smart Dubai City Social Policies

This study explores the sociological perspective required for achieving holistic and sustainable development in social contexts. It focuses on Dubai as a smart city exemplar, investigating the integration of comprehensive development that encompasses social, economic, cultural, and technological aspects, as well as sustainable development that includes environmental sustainability. The research provides valuable insights into Smart Dubais social dimensions and highlights its commendable efforts towards sustainable social development. The discussion explores the various social policies implemented in Dubai, which serve to regulate the conduct, initiatives, and practices of both the government and non-governmental entities, as well as individuals, in order to address a wide array of social challenges. Furthermore, it explores the application of certain development theories, such as post-modernism, and how they have contributed to Dubais cultural shift towards embracing socio-economic standards. Additionally, the theory of ecological modernization is examined, highlighting its role in integrating environmental concerns with social institutions that promote sustainable policies for the advancement of a smart city. The research employs a case study methodology, analyzing secondary data and official records to assess Smart Dubais policies and highlight its social sustainability development. Findings reveal that Smart Dubai has made significant progress in embracing social issues through its policies, and it is on the road towards social sustainability in terms of family unity, gender equality, demographic balance, health, education, popular participation and balancing in terms of services between UAE citizens and expatriates. The research recommends that Dubai have a bureau for studying policies to mitigate social challenges and phenomena as well as an authority for collecting social data

Synthesis and Antibacterial Activity of some 5,5’-(1,4-phenylene)-bis-1,3,4-Oxadiazole and bis-1,2,4-Triazole Derivatives as Precursors of New S-Nucleosides

Five compounds, namely 5,5’-benzene-1,4-diylbis(1,3,4-oxadiazole-2-thiol)6 and 5,5’-benzene-1,4-diylbis(1H-1,2,4-triazole-3-thiol) 7a and its derivatives 7b–d were synthesized. Two related S-nucleosides 9 and 10 have been prepared from 6 and 7a. Some of these synthesized compounds were tested in vitro by spotting on Mueller Hinton Agar medium against some Gram-positive bacteria, Staphylococcus aureus and Enterococcus faecalis and three Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, Pseudomonas fluorescens and compared with the known antibiotics cephalosporin (cefotaxim) and gentamycin. Compound 6 showed significant inhibitory activity against Gram-positive E. faecalis and Gram-negative E. coli bacteria while the others have shown variable inhibition activity.Keywords: Terephthalic acid, 1,3,4-oxadiazole, 1H-1,2,4-triazole, S-nucleosides, antimicrobial activit

DM model transformations framework

Metamodelling produces a \u27metamodel\u27 capable of generalizing the domain. A metamodel gathers all domain concepts and their relationships. It enables partitioning a domain problem into sub-problems. Decision makers can then develop a variety of domain solutions models based on mixing and matching solutions for sub-problems indentified using the metamodel. A repository of domain knowledge structured using the metamodel would allow the transformation of models generated from a higher level to a lower level according to scope of the problem on hand. In this paper, we reveal how a process of mixing and matching disaster management actions can be accomplished using our Disaster Management Metamodel (DMM). The paper describes DM model transformations underpinned by DMM. They are illustrated benefiting DM users creating appropriate DM solution models from extant partial solutions

Synthesis of Novel Thieno[3,2-b]quinolines and Thieno[3,2-d][1,3]thiazoles

New heterocyclic 2-Aryl-9-chloro-5,6,7,8-tetrahydrothieno[3,2-b]quinoline derivatives [Aryl-CTTQ] (2a–e) and 5-arylthieno[3,2-d][1,3]thiazol-2-amine derivatives[Aryl-TZA] (6a–e)were achieved in good yields starting from 5-aryl-3-aminothiophene-2-carboxylic acid (1a–c).Keywords: 5-Aryl-3-aminothiophene-2-carboxylic acid, thieno[3,2-b]quinoline, thiourea, thieno [3,2-d][1,3]thiazol

Effect of leptin level in non insulin dependant (type 2) obese diabetic subjects

Background: Determine how do obesity and type2 diabetes intertwined? and what it takes to turn an obese person into a person with diabetes. That link may help to understand why some obese people never develop diabetes while many others do. Serum sugar level was used as indicator of insulin level; leptin level was used as indicator of leptin resistance. A total of 50 obese subjects were involved in this study, 25 obese subject (BMI >30) had diabetes mellitus type 2(no insulin dependant), selected from Baghdad teaching Hospital in Baghdad /Iraq. The remaining 25 obese (BMI >30) were normal healthy individuals. Patients and Methods: ELSA technique was used for the measurement of serum leptin. Blood sugar was determined by using colorimetric method. Data were expressed as mean ± SD results and were evaluated using the student t-test for paired data. Conventional methods were used for the correlation and regression analyses. Results: Obtained results showed that the level of serum leptin in healthy obese subjects were significantly lower than that of obese diabetes subjects. , serum sugar in non diabetic obese subjects was significantly lower than obese diabetes type2 subjects. Serum leptin correlated negatively with level of serum sugar at the same time had a positive correlation with BMI in non diabetic obese group whereas level of serum leptin correlated positively with each of BMI and serum sugar in diabetic type2 group. All results are thoroughly discussed in the text. Conclusion: The present study indicates the possibility of future development of a new class of anti diabetic agents that act centrally and independent of insulin action

Evaluation of Trace Metal Levels in Tissues of Two Commercial Fish Species in Kapar and Mersing Coastal Waters, Peninsular Malaysia

This study is focused on evaluating the trace metal levels in water and tissues of two commercial fish species Arius thalassinus and Pennahia anea that were collected from Kapar and Mersing coastal waters. The concentrations of Fe, Zn, Al, As, Cd and Pb in these coastal waters and muscle, liver and gills tissues of the fishes were quantified. The relationship among the metal concentrations and the height and weight of the two species were also examined. Generally, the iron has the highest concentrations in both water and the fish species. However, Cd in both coastal waters showed high levels exceeding the international standards. The metal level concentration in the sample fishes are in the descending order livers > gills > muscles. A positive association between the trace metal concentrations and weight and length of the sample fishes was investigated. Fortunately the level of these metal concentrations in fish has not exceeded the permitted level of Malaysian and international standards