Appropriate renewable hybrid power systems for the remote aboriginal communities

Renewable power supply systems have been a natural choice for many of Australia’s small remote aboriginal communities where the costs of diesel fuel are high. The results have been mixed. This is partially due to design factors, but more importantly due to community acceptance of these technologically complex systems and the maintenance arrangements with the community power station operators and local resource agencies. This paper looks at some of the issues to consider in the selection, design, installation and maintenance of appropriate hybrid power stations for smaller remote aboriginal communities.     

A hardware in the loop simulation platform for vision-based control of unmanned air vehicles

Design and testing of control algorithms for unmanned air vehicles (UAV’s) is difficult due to the delicate and expensive nature of UAV systems, the risk of damage to property during testing, and government regulations. This necessitates extensive simulation of controllers to ensure stability and performance. However, simulations cannot capture all aspects of a flight control, such as sensor noise and actuator lag. For these reasons, hardware in the loop simulation (HILS) platforms are used. In this paper, a novel HILS platform is presented for vision-based control of UAV’s. This HILS platform consists of virtual reality software to produce realistic scenes projected onto a screen and viewed by a camera. Flight hardware includes an UAV with onboard autopilot interfaced to the virtual reality software. This UAV can be mounted in a wind tunnel, allowing attitude regulation through servoing the airfoils.     

Reactive Power Compensation Technologies: State-of-the-Art Review

This paper presents an overview of the state of the art in reactive power compensation technologies. The principles of operation, design characteristics and application examples of Var compensators implemented with thyristors and self-commutated converters are presented. Static Var generators are used to improve voltage regulation, stability, and power factor in ac transmission and distribution systems. Examples obtained from relevant applications describing the use of reactive power compensators implemented with new static Var technologies are also described.     

Impact of Business Practices on Individual Energy Consumption

Changing behaviours and attitudes towards more sustainable individual energy consumption is a difficult topic to address. After identifying the most recurrent factors influencing the bad energy consumption, society's environmental short-sightedness, a lack of individual responsibility and a tendency to put responsibility upon firms, institutions, and governments, the authors evaluated the effect that business practices can have on individual behaviour. By qualifying as highly credible sources of information, positioning themselves as examples to follow, and providing its employees with the necessary smart and innovative technology, business communities can have a major impact on changing individual behaviours towards more sustainable energy consumption.     

Radio Spectrum Management for Tetherless Communications

For any new radio technology, spectrum management is an essential part of the development process, to identify the best frequency band for operation of the system. This has to take account of the many other users and applications of the radio spectrum, so that systems neither cause, nor receive, harmful interference from other radio systems. It is a process that is sometimes considered to be unnecessarily restrictive and slow; however, that is because it is often a difficult balancing act between the technical, commercial and political pressures on the (finite) radio spectrum. This paper describes the underlying principles and processes of radio spectrum management, explaining the relationships between the organisations which are responsible for spectrum management at the national, regional and international levels. It also describes the current work on the identification of frequency bands for the new tetherless communications technologies, and in particular the 2.4 and 5 GHz bands. This revised version was published online in July 2006 with corrections to the Cover Date.     

Response of pocket gophers (Thomomys talpoides) to an operational application of synthetic semiochemicals of stoat (Mustela erminea)

This paper reports on laboratory bioassays and a large-scale field trial of synthetic mustelid anal-gland compounds in controlled-release devices designed for operational application to burrow systems of northern pocket gophers (Thomomys talpoides). The field study was conducted in an apple orchard in the Okanagan Valley of British Columbia. In laboratory bioassays, a 1∶1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane from the stoat (Mustela erminea) and 3,3-dimethyl-1,2-dithiolane from the ferret (M. putorius), dispensed in clay pellets (activated alumina), produced a significant avoidance response by gophers. All resident gophers were permanently removed from 4-ha control and treatment blocks prior to placement of stoat odor in burrows. As indexed by soil mounds, significantly fewer gophers colonized the treatment (40) than the control (68) removal area during a 5.5-month overwinter experiment. There was also a significant difference when comparing the number of mounds between pre-(79) and posttreatment (40) censuses. In addition, most gopher activity tended to occur on the perimeter of the treatment block. Abundance of gophers showed little difference between additional 4-ha control and treatment blocks where gophers had not been removed. The results of this study provide an alternative technique to toxicants for pocket gopher control on forest and agricultural land.     

Antipyrine: radioimmunoassay in plasma and saliva following administration of a high dose and a low dose

The body's equilibrium is possible thanks to the integration of skeletal structure, vertebrae, ligaments and muscles to form one functional unity. The forces which determine posture are composed of two complementary systems, the ligamentary and the muscular systems, which together determine a dynamic act of balance. The ligaments operate mainly against the visco-hydraulic pressure of the nucleus pulposus and bind the vertebral bodies together, whereas the muscles exhibit an antigravity function and support spinal stability. A mathematical model based on a mixed theory of directed and oriented curves is proposed. Through this model it is possible to develop an exact theory governing the deformation of the ligamentous spine. This theory should be universal in the sense that it can be used to supply the spine in any of its environments.     

Diacetyl in Foods: A Review of Safety and Sensory Characteristics

Diacetyl, noted for its appealing butter‐like aroma, is present naturally in many foods, and humans have been exposed to it since the beginning of civilization. The advent of microwave (MW) cooking technology has led to the development of a significant market for MW popcorn, to which diacetyl and other flavoring compounds have been frequently added. Based upon reported associations between diacetyl inhalation and lung disease in employees of MW popcorn processing facilities, a very conservative safe level of occupational exposure to diacetyl has been proposed by the American Conference of Governmental Industrial Hygienists. Yet there is conflicting evidence that diacetyl causes lung disease in workers, and no evidence to condemn diacetyl as the cause of lung problems in MW popcorn consumers. Consumer dietary exposure to diacetyl in foods is below levels of health concern while common airborne levels of diacetyl from MW popcorn are far below the conservatively established limit to protect workers.     

Cognitive responses to stress: Effects of changes in demand and sex.

Replicated a previous study with female Ss by M. J. Horowitz and S. Becker (see record 1972-02452-001) testing the theory that increased intrusive and repetitive thought after exposure to stressful events is a cognitive response tendency occurring in general population groups. Reports by 1 female and 27 male students of mental contents before and after neutral and stress films were analyzed. Data contrasted for male and female Ss and for different instructional demands show that the stress film exerted a significant influence on increase in intrusive and stimulus-repetitive thought; male-female differences and demand effects were nonsignificant. Results support the hypotheses that intrusive and repetitive thinking are general cognitive responses to stress and that such changes in conscious experience can be quantified in the laboratory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)