Riadh W. Y. Habash

Recent Advances in Research on Radiofrequency Fields and Health: 2001–2003

The widespread use of wireless telecommunications devices, particularly mobile phones and wireless networks, has resulted in increased human exposure to radiofrequency (RF) fields. Although national and international agencies have established safety guidelines for exposure to RF fields, concerns remain about the potential for adverse health outcomes to occur in relation to RF field exposure. The extensive literature on RF fields and health was reviewed by a number of authorities, including the Royal Society of Canada (1999). This report is the third in a series of updates to the original report of the Royal Society of Canada, covering the period 2004–2007. In particular, the present study examined new data on (1) dosimetry and exposure assessment, (2) biological effects of RF fields such as enzyme induction, and (3) toxicological effects, including genotoxicity and carcinogenicity. Epidemiological studies of the potential health effects of RF exposure, particularly from mobile phones, were determined, along with human and animal studies of neurological and behavioural effects. Within the last 4 yrs investigators concluded that there is no clear evidence of adverse health effects associated with RF fields, although continued research is recommended to address specific areas of concern, including exposure to RF fields among children using mobile phones. The results of the ongoing 13-country World Health Organization INTERPHONE study of mobile phones may provide important new information on the potential cancer risks associated with mobile phone use.

Electromagnetic Fields and Radiation: Human Bioeffects and Safety

Introductory topics. Part 1 Extremely low-frequency fields: sources of electric and magnetic fields bioeffects of ELF fields epidemiological assessment studies regulatory activities and safety trends. Part 2 Radio frequency radiation: sources of radio frequency radiation introduction to bioelectromagnetics bioeffects of radio frequency radiation human and epidemiological studies RF regulations and protection guidelines incident field dosimetry RF site surveys internal field dosimetry acronyms and abbreviations.

Performance of a Contrarotating Small Wind Energy Converter

Responding to more demand in coming years, the task of the small wind energy industry requires progress on several fronts—the public policy initiatives, technology development, and market growth. One important issue of the wind energy utilization is the conversion efficiency of the usable energy into productive power. Enhanced technologies such as contrarotating blades, gearbox and lubrication, airfoils, generators, and power electronics will lower cost and increase energy production. The purpose of this paper is, therefore, to reinforce the effectiveness of employing contrarotating system to enhance the performance of a small wind energy converter (SWEC). With this concept, the SWEC works more efficiently and therefore produces more energy in a unit turbine area. To verify the SWEC performance, a research model has been built and tested over a range of operating conditions. Wind tunnel tests were carried out to ascertain the overall performance of the contrarotating SWEC. Results are presented for cases of different wind speeds and Reynolds number. The results demonstrated a significant increase in wind energy conversion efficiency and capability of operation at lower wind speeds while keeping up performance compared to a single-rotor system of the same type.

Microstrip patch antenna for RFID applications

The microstrip patch antenna is a popular printed resonant antenna for narrow-band microwave wireless link applications such as radio frequency identification (RFID) systems that require semi-hemispherical coverage. In this paper, a 865 MHz microstrip patch antenna fed by a microstrip line designed on a substrate is considerably studied and thoroughly analyzed. The antenna has been designed using the 3D High Frequency Structure Simulator (HFSS). The initial design provides a gain of 4.2 dBi, while the final optimized design achieved a total antenna gain of 5.6 dBi and a return loss or reflection coefficient (S11) of −35dB at 865 MHz for 116 mm patch length. Modeling and optimization of the presented microstrip patch antenna has produced results that are suitable for RFID applications.

A risk assessment framework for the smart grid

The smart grid, generally referred to as the next generation power electric system, relies on robust information and communication technologies (ICTs) to provide efficient, secure, and reliable information delivery. The implementation of the smart grid includes the deployment of multiple new infrastructures with vulnerabilities that have not yet been identified. Therefore, the traditional focus on security, reliability, compliance, and human safety is a paramount concern. This paper first addresses critical issues of smart grid primarily in terms of ICTs and standards. A risk-based approach has been presented, which could be implemented to address the security aspects and health impact of the smart grid. The paper evaluates the security threats to the smart grid as well as the health risks of smart meters currently under implementation in the context of radio frequency (RF) radiation. Finally, a combined framework for risk management in major technological and health domains has been proposed. Such a framework calls for a coordinated assessment of cyber and power grid risks keeping the whole grid security and safety goals in mind.

Performance Testing and Control of a Small Wind Energy Converter

Responding to more demand in coming years, the task of the small wind energy industry requires progress on several fronts—from public policy initiatives, to technology development, to market growth. Enhanced technologies such as contra-rotating blades, transmission systems, lubrication, airfoils, generators, and power electronics will lower cost and increase energy production. This paper mainly considers two key technological points of a small wind energy converter (SWEC) namely, the performance of the rotor system and induction generator. Small-scale prototypes have been built to experimentally verify the performance of the SWEC. Wind tunnel tests of the power output, power coefficient, and turbine speed were carried out to ascertain the aerodynamic power conversion and the operation capability at lower wind speeds. The results demonstrated a significant increase in performance compared to a single-rotor system of the same type. Another aspect of development and test is to present a comparative performance evaluation between a standard induction generator and an efficient but with modified design (TRIAS Generator) as a realistic solution of clean power for grid-connected SWECs. The paper also discusses issues related to control and monitoring of SWEC.

Sustainable Design of a Nearly Zero Energy Building Facilitated by a Smart Microgrid

One of the emerging milestones in building construction is the development of nearly zero energy buildings (NZEBs). This complex concept is defined as buildings that on a yearly average consume as much energy as they generate using renewable energy sources. Realization of NZEBs requires a wide range of technologies, systems, and solutions with varying degrees of complexity and sophistication, depending upon the location and surrounding environmental conditions. This paper will address the role of the above technologies and solutions and discusses the challenges being faced. The objective is to maximize energy efficiency, optimize occupant comfort, and reduce dependency on both the grid and the municipal potable water supply by implementing sustainable strategies in designing a research and sports facility. Creative solutions by the architectural and engineering team capitalize on the design of a unique glazing system; energy efficient technologies; water use reduction techniques; and a combined cooling, heating, and power (CCHP) microgrid (MG) with integrated control aspects and renewable energy sources.

Harnessing the Winds: Trends and Advances

Power is available from two different sources: nonrenewable (coal, fuel, natural gas) and renewable (wind, solar, hydro, wave). Nonrenewable sources have limited potential and they are expected to diminish within the next centuries due to high rates of exploitation. This is one of many other reasons why clean and renewable energy resources are currently sought.

Performance optimization of a dual-rotor wind turbine system

We are building an efficient and smart wind turbine system. The significant features of this turbine are its dual rotor blade system which is positioned horizontally at upwind and downwind locations, its drive train which is installed horizontally inside the tower with a new efficient induction generator, and its control and safety systems. The project focuses mainly on the methodology to analyze the power flow performance. The scientific literature indicates that a dual-rotor system could extract additional 20–30% power compared to a single rotor system from the same wind stream. Our wind tunnel test indicates that a scaled-down version of the dual-rotor turbine system may produce up to 60% more power than a single-rotor system. Designed for on-site power generation by commercial, industrial, and residential electric users in remote locations, our model uses wind tunnel effect to capture and amplify wind for optimized production of energy. It is intended that this turbine system will be available in tower-mounted design and can capture wind in regions where it has low speed wind. The successful design should allow an economical transition to a utility scale.

Foreseeable Health Risk of Electric and Magnetic Field Residential Exposures

Exposure to electric and magnetic fields (EMFs) emanating from the generation, distribution and utilization of electricity is widespread. The major debate in recent years has been the possibility that EMFs influence various effects on the human body especially development of cancer. Epidemiologists were the first scientists to publicize this fact through human population studies. Current investigations into this topic split up over diverse areas of research. This paper provides a review of information on health risk of EMF residential exposure. Four major areas have been considered for evaluating the possible risks with emphasis on recent studies. These include safety standards for EMFs, residential field measurement surveys, biological and epidemiological studies of diseases with foreseeable association with EMFs including childhood leukemia, breast cancer, and pregnancy adverse outcomes. On the basis of review findings, it is difficult to provide a robust conclusion about health risk of EMFs, raising the significance of researching this area further. No policy advise is offered, however, as a voluntary precautionary measure, public health professionals, regulatory authorities, standard setters, electric utilities, and individuals are encouraged to advocate minimizing EMF exposures wherever possible.