Olympics watch - [engineering london 2012]

THE OLYMPIC STADIUM is the focal point of any Games. It is the place where, arguably, all the highest profile events take place, and where the world?s top performers set about smashing the iconic records set by the legendary athletes of the past. The stadium is also the place that remains etched onto the memory long after the Olympic torch has passed on. Memories of 2012 will be of a stadium in London.     

Feeding the power [power biofuels]

A controlled experiment, perhaps: divide a country in two, and feed only one half properly. One way to see the importance of good nutrition is to look at the countries on each side of the Demilitarised Zone on the Korean peninsula. In North Korea, plagued by endemic food shortages for decades, average heights are 18cm shorter than in richer, better fed South Korea.     

High power [Power]

The famous ?war of currents? between Thomas Edison, champion of direct current systems, and alternating current advocate Nikola Tesla was won by Tesla. Until a few decades ago, practically all transmission systems were AC. Technological advances, however, have caused DC to gain favour and, although most systems are still AC, Edison might still have the last laugh.     

Poised for power [power over Ethernet]

This article details the power-over-Ethernet specification (802.3af) which defines a method to deliver power to devices such as IP phones and security systems from networking equipment such as routers and switches. This takes place over the same twisted-pair cable used to carry data over Ethernet networks, and removes the need to install separate power wiring or rely on sources derived from a wall-mounted power supply. Accounting for typical losses in the cabling, this system permits each powered device (PD) to draw up to a maximum of 12.95 W. Each PD must include at least one DC/DC converter that transforms the input voltage to levels that suit its construction and also provides a 1500 V isolation barrier. To stay active, the device under power must draw a minimum current of 10 mA. This allows detection logic within the power source to remove power to a port when equipment is disconnected. The article also discusses revisions to the specification which would enable higher power levels to be supplied.     

Lovelock's choice [nuclear power]

This paper presents the controversial views of British environmentalist, James Lovelock, on the issue of nuclear energy. Lovelock believes that the UK should take advantage of nuclear power for its energy needs and proposes the adoption of Finland's nuclear waste management program. He, however, does not favor building new nuclear power plants but instead suggests extending the lives of the current crop of nuclear facilities. Lovelock expresses his frustration over the so-called modern environmentalists and explains his views on renewable technologies. While he does not believe in wind and solar, he favors tidal generation and carbon capture. Lovelock also expressed concern over the climate crisis, saying that the Earth's systems are responding to the changes humans have made to the planet by shifting itself to a new physiological state.     

Atomic agents [atomic power]

This paper presents an interview with Yuri Sokolov, deputy director general of the UN's International Atomic Energy Agency (IAEA), about some issues regarding the development and proliferation of nuclear weapons throughout the world and how the IAEA works to prevent the spread of nuclear arms and promote the safe use of atomic power.     

Brave new world [nuclear power]

In the run up to the parliamentary election, the media has reported UK government plans for nuclear build; one report in The Independent on Sunday declares a 'secret' Department of Trade and Industry (DTI) team has made a case for building up to 10 nuclear reactors. Fact or fiction, it is difficult to deny a mood swing is taking place across the globe. This article looks at developments in nuclear power around the world, and the UK's indefinite position on nuclear generation.     

All at sea [tidal power]

Being an island nation regularly feeling the force of the Atlantic down its western coasts, the UK is well placed to harness tidal and wave power. The largest single potential source of tidal energy in the UK lies in the Severn Estuary, where the tides are the highest in Europe. Developers believe a barrage built across the estuary could provide as much as 7% of the power needs of England and Wales. There are concerns, however, that the barrage could have a negative impact on the existing habitat and wildlife. Alternatives to the barrage have been put forward including the installation of tidal lagoons which would have a significantly less environmental impact than a full-bodied barrage.     

Milking the microbes- [power biofuels]

Until recently, biofuels had been a much heralded answer to our growing CO2 emissions from transport. That was until controversy erupted over their use of feedstocks that are needed to feed the spiralling world population.     

False alarm [wind power generation]

This article looks at the operation of an electricity system with wind energy generation, and the misconceptions surrounding the use of this and other intermittent renewable energy sources. An overview of wind generation and its economics related to the electricity supply industry as a whole finds that far from being a liability, wind could be an asset.     

Fresh forecasts [wind power forecasting]

Wind power forecasting falls broadly into two headings: statistical or physical modelling. Statistical modelling makes no real attempt to model the physical processes that drive the wind, but relies on previous wind speed patterns over time to make a prediction. In contrast, physical modelling tries to understand the physical processes that drive the wind, such that with sufficient input data, a model of the physical system can make a prediction some time into the future. In practice, a combination of statistical and physical modelling is used to provide an optimum wind power forecast over a time-horizon that may stretch out to 48 hours or more. To this end, a range of different 'model chains' can be used to forecast wind power.     

Bionic batteries - [electronics power]

Things don?t change quickly in battery design. The choice of materials to make better batteries is pretty limited and the core material ? lithium ? has been a feature of batteries with high energy densities for a long time already. The first lithium battery appeared in the early 1970s, although they were not rechargeable systems.     

Power shift - [power asia]

Today, the players in the great energy game are different to what they used to be. They include Russia, China, Iran and Turkey, the traditional regional powers, but they also include new players such as the EU, USA , India, drug smugglers and religious extremists. However, the strategies are traditional ? economic, political, military, diplomatic and religious.     

Cuba's power struggle [Power Cuba]

Climate change represents a challenge to all world governments, but Nicholas Newman finds that in Cuba, the problem is as serious as securing stable and affordable energy supplies for its citizens.     

Hot pursuit [configurable power supplies]

In the race to win market share, power suppliers are making real breakthroughs in configurable devices. The article looks at one device and its competitors. A former power distributor, XP, is aiming to take on leading suppliers of AC/DC power systems in Europe. XP has transformed itself from distributor to manufacturer with a series of acquisitions, re-branding itself as XP Power. XP recently released a configurable power supply called Flexpower. The AC/DC system is configurable from a universal input, providing 400 to 900 W at 3.3 to 60 V with a high line option that can bring the power output to 1100 W. Two chassis together can provide up to 2200 W. XP believes that the ability to connect units with different power levels allows system designers to specify the power level they need for different applications without having to pay extra for additional power capabilities. UK-based Lambda also has a range of AC/DC supplies. Their HWS series runs from 15 to 150 W versions, with nominal output voltages selectable from 3.3, 5, 12, 15, 24 or 48 V Each model accepts a continuous input from 85 to 265 VAC. California-based Astec Power, is also confident that configurable AC/DC power supplies form part of a major growing market.