Development of an FPGA-based gate signal generator for a multilevel inverter

The application of Field Programmable Gate Array (FPGA) in the development of power electronics circuits control scheme has drawn much attention lately due to its shorter design cycle, lower cost and higher density. This paper presents an FPGA-based gate signal generator for a multilevel inverter employing an online optimal PWM switching strategy to control its output voltage. FPGA is chosen for the hardware implementation of the switching strategy mainly due to its high computation speed that can ensure the accuracy of the instants that gating signals are generated. The gate signal generator has been realized by an FPGA (FLEXlOKZO) from Altera. The design and development of the FPGA based gate signal generator is described in detail. Results from the timing simulation using MAX+PLUSII software are given and verified by the results obtained from the FLEXlOK2O output

Axial anomaly of QED in a strong magnetic field and noncommutative anomaly

The Adler-Bell-Jackiw (ABJ) anomaly of a 3+1 dimensional QED is calculated in the presence of a strong magnetic field. It is shown that in the regime with the lowest Landau level (LLL) dominance a dimensional reduction from D=4 to D=2 dimensions occurs in the longitudinal sector of the low energy effective field theory. In the chiral limit, the resulting anomaly is therefore comparable with the axial anomaly of a two dimensional massless Schwinger model. It is further shown that the U(1) axial anomaly of QED in a strong magnetic field is closely related to the ``nonplanar'' axial anomaly of a conventional noncommutative QED.Comment: 18 pp, no figure. v2: The version accepted to be publidhed in PR

Construction Site Workers’ Awareness on Using Safety Equipment : Case Study

Construction sector is an important sector and contributed significantly to national development. However, this sector poses higher risk to accident. This is due to fact that construction site can be considered as a dangerous zone to workers and to the public. Due to the variety of cases occurs on site, the contractor will usually have to pay the cost related to accidents in the form of higher insurance premium. Despite various measures, accidents still occur at construction sites. Personal Protective Equipment (PPE) is one of the important means to protect the wearer from hazards in the workplace. Since this equipment is the last frontier of the wearer from worksite hazards, it is important to select it based on the job scope and the intended protection. Therefore, this study was formulated to find out the level of knowledge and awareness of construction workers on PPE usage. It was also important to know what make the workers would want or do not want to use the PPE. It was found in this study that the level of awareness and knowledge among workers on the proper use of PPE is moderate. Construction sites accident can be further be reduced with proper implementation of PPE voluntarily by all workers

Leaf blight disease of coconut 2. studies on Curvularia sp

The cultural behaviour of Curvularia lunata Wakker, which caused lesions in leaves of coconut seedlings, was studied on different agar media. Temperature -growth studies indicated that the colony growth and sporulation were best at 30 perc. The optimum temperature for germination of conidia on water agar was 30 perc. Germination was reduced with the increase of concentration of conidia, and was less on leaf surface than on water agar. When coconut leaves were inoculated with C. eragrostidis which was occasionally isolated from lesions, failed to produce any symptoms on inoculatio

The Evolution of Paediatric Cardiology Service in Oman

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Impact of Chinese engines in the marine fishing sector of Kerala

Impact of Chinese engines in the marine fishing sector of Keral

Subsidies in Indian fisheries-Methodological issues and implications for the future

Subsidies are financial contributions made by Government or public bodies which provide a private benefit. Westlund (2003) defined fisheries subsidies as “government actions or inactions that are specific to the fisheries industry and that modify – by increasing or decreasing – the potential profits by the industry in the short, medium or long-term”. World attention was drawn to the scale of the global fisheries crisis and also the extent of fishery subsidies in 1992 with the publication of an FAO report, Marine Fisheries and the Law of the Sea: A Decade of Change. The adverse effect of subsides depend on the existing management regime and the bioeconomic conditions of the fishery. Subsidies lower the cost of harvest and raise the effective price of fish. As a management tool, cost-reducing or profit-increasing subsidies may result in increased productive efforts and hence considered as harmful through over exploitation of fish resources and unsustainable harvesting

Constraint analysis on the impediments faced by Indian seafood exporters

Among the leading non traditional exports, fish and fishery products play a prominent role contributing significantly to the success of India's export effort to bridge the yawning trade gap of India.They have become one of the major foreign exchange earners in the agricultural and a1lied sectors of India in the recent years. Starting from mere scraps in the pre independence period, it is a saga of steady striking and sustained growth that the industry had recorded raising India's status and prestige and securing for her a respectable position among the maritime nations of the worl