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April 8, 2007
March 27, 2007
Rapid improvements to the efficiency and power of light-emitting diodes (LEDs) will soon allow the decades-old technology to revolutionize how we illuminate our world, according to an industry expert.
Mass adoption of LEDs could cut global electricity use by 10 percent, said George Craford, chief technology officer for Philips Lumileds in San Jose, California.
Craford presented a review paper on the latest LED advances last Tuesday during a meeting of the American Physical Society in Denver, Colorado.
A switch to LEDs in place of conventional lighting would save “a huge amount of electricity and a huge amount of money,” he told National Geographic News.
The energy savings “will amount to well over a hundred nuclear power plants worldwide.”
Materials scientist Steve DenBaars directs a research center at the University of California, Santa Barbara (UCSB), that focuses on energy-efficient lighting and display technologies like LEDs.
DenBaars said that Craford’s estimate of energy savings may be a slight overstatement, “but it’s on that scale.”
“Twenty-two percent of [U.S.] electrical energy consumption goes into lighting, and we’re talking about taking the efficiency up several factors here and taking that number down to like 3 or 4 percent,” he said.
By that calculation, he said, energy-efficient lighting could save the U.S. the equivalent of the power produced annually by 133 coal-fired power plants.
LEDs are tiny devices made of semiconductors—solid materials such as silicon that have varying abilities to conduct electricity.
Since the 1960s scientists have known that LEDs made from different semiconductors glow at different colors when voltage is applied (see a related photo of LEDs being tested at a semiconductor factory).
Unlike regular incandescent bulbs, LEDs emit light without a wire filament, so they take longer to burn out, and they produce less heat.
But semiconductors have long been too expensive for use in a broad range of commercial applications. Until the 1990s LEDs were primarily used only as indicator lights, such as those in power buttons on electronic gadgets.
oday the costs of semiconductors are dropping by about half each year, according to DenBaars.
Craford, of Philips Lumileds, said that advances in the materials and designs used to make LEDs have also led to dramatic improvements in how light is generated and extracted.
While no single breakthrough stands out, Craford said, the cumulative advances translate to higher production and output.
“We are generating more light inside the [semiconductor] chip and we are getting more of what we generate out, and that makes the total output substantially higher,” he said.
UCSB’s DenBaars said that increasingly complex structures drawn on the semiconductor chips themselves have led to the improved light extraction efficiency.
It’s “literally like drawing lenses on the chip,” he said.
“Holy Grail” of Lighting
Within the last decade colored LEDs have been widely adopted for uses such as exit signs, traffic lights, and automobile taillights, Craford noted.
The U.S. Department of Energy reported in 2003 that these types of niche applications already save the country 9.6 terawatt hours a year of electricity.
Perhaps the biggest remaining challenge is to create efficient and economical white-light LEDs, Craford said.
LEDs by their nature give off distinct colors—one type of material glows green while another glows blue. But white is a combination of colors, Craford explained.
To make white light with an LED, scientists most commonly add a yellowish phosphorescent chemical to a blue-emitting diode. The combination of yellow and blue gives an appearance of white to the human eye.
(Related news: “Accidental Find to Signal ‘Lights Out’ for Incandescent Bulbs?” [November 1, 2005].)
Advances in phosphor technology have already given white LEDs traction in the marketplace, especially in flashlights, according to Craford.
And he believes that as the technological advances continue, white LEDs “will replace conventional lighting for most general illumination purposes.
“I happen to believe it will replace virtually everything,” he added.
A complete switch from modern light bulbs, though, could still be decades distant, he noted. Currently the best LEDs are about as efficient as compact fluorescent light bulbs.
These bulbs are five times more energy efficient than incandescent bulbs and are a much cheaper option than LEDs.
Noah Horowitz is a senior scientist with the nonprofit Natural Resources Defense Council in California.
He said through a spokesperson that LEDs that are more efficient than compact fluorescent bulbs are the “holy grail” of lighting, and the environmental group is optimistic about the use of LED technology in the future.
But today, he said, “they cost a lot and are not yet widely available for consumer applications.”
Horowitz added that obtaining white light from LEDs that resembles the light of an incandescent remains a challenge, as does spreading the light out from the LED.
Currently, Horowitz said, LEDs are good at providing directional lighting, such as in a spotlight, but not as good for practical uses in things such as table lamps.
Philips Lumileds’ Craford is confident that these improvements are coming and will soon make LEDs the light source of choice.
“LEDs are going to be a substantial part of the lighting in the upcoming years,” he said, “and it’s beginning to happen right now.”
February 23, 2007
– A Case Study Of The Sarawak – Kalimantan Border of Malaysia and Indonesia
Malaysia shares a number of strategic border regions in terms of national security between members of the ASEAN countries. These border regions are in the form of river demarcating boundary lines as in the case of the northern border region that separates West Malaysia from Thailand, or in the form of a water body such as the Straits of Malacca that separates the Island of Sumatra from Peninsular Malaysia or the Straits of Johore that separates Singapore from Peninsular Malaysia. East Malaysia too shares strategic border areas from neighbouring ASEAN countries. The state of Sabah is separated from the islands of Pahlawan and Mindanao in the Phillippines by the Sulu Sea, whilst the states of Sarawak and Sabah in East Malaysia are separated by a mountainous landmass from the state of Kalimantan in Indonesia. These border regions are strategic areas, as it encourages illegal migration and illegal cross border activities that are a threat to the national security of the Malaysia. This paper attempts to model the activities of illegal migration at the Sarawak – Kalimantan border of Malaysia – Indonesia and how it influences the national security of West Malaysia (Malaysia). The model was based on an extensive field study carried out in 1998 which included an exhaustive questionnaire survey on the settlement inhabitants of the region. The thrust of the paper relates national security to the inflow and illegal smuggling of weapons, drugs, diseases and the indirect impact of border land clearing and the problem of pollution associated with uncontrolled land resources exploitation at the border region.
Khairulmaini Bin Osman Salleh, PhD(1) & Fauza Ab Ghaffar, PhD(2)
February 12, 2007
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On 14 November 2006, Scottish Executive Social Research in conjunction with the Scottish Executive Geographic Information Service team (SEGIS), held an afternoon seminar on the role of Geographic Information Systems (GIS) in Government Social Research.
The demand for the seminar came from two quarters, which were introduced at the seminar’s outset: the launch of a strategy paper called ‘One Scotland One Geography’ and SE Social Research’s commitment to developing professional skills in geospatial analysis to make most effective use of government data.
In November 2005, the ‘One Scotland One Geography’ Strategy was launched, which sets out a proposed approach to the more systemic and effective use of geographic information in the development and delivery of policies and services to the benefit of the people of Scotland. It mirrors a similar strategy paper currently being developed in Whitehall. The strategy recognises that geographic information is fundamentally important to the daily lives of every person and organisation in Scotland – “everyone is always somewhere” the first speaker argued – and is increasingly important to the delivery of better, more efficient, cost effective and responsive public services. All public sector employees in Scotland have a commitment to the strategy which has now become part of the Efficient Government agenda and will be implemented between.
Social researchers have a role to play in driving forward the strategy and the presentations that followed provided useful illustrations of how GIS has been applied in social research. The key note presentation, given by Andrew Crooks of University College London, introduced GIS and its various policy applications. These range from identifying clusters of health inequalities to spatial analysis of crime and policing. The presentation demonstrated that one of the main advantages of GIS is its ability to condense vast amounts of data into manageable and accessible information, which enables more efficient use of data sources. It confirmed too that GIS has benefits beyond mapping and spatial analysis. It allows analysis and join-up of data in different ways that conventional social science methods would not allow or would be too time consuming to consider.
Postcard presentations followed, which provided snapshot examples of GIS analysis undertaken by analysts in the Scottish Executive and confirmed these attributes. The postcards covered patient experiences of the Health System, urban/rural classification in the Scottish Household Survey, Scottish Neighbourhood Statistics, small area crime data, and the Scottish Executive Travel Survey 2006. The latter postcard, for example, identified the clear visual impact that GIS can have; an impact which is appreciated and easily understood by many policy colleagues.
In a facilitated workshop session, researchers discussed the pros and cons of the method in a social research setting, and while GIS can be criticised for being too deterministic, the groups concluded that GIS could be used to complement other methods, strengthening a combined methods research approach that would deepen understanding of social and spatial phenomena.
The workshop also developed an understanding of the planning required to add a geographical dimension to social research work, and especially the need to draw on the support of specialists. It was reassuring to hear that, with dedicated support from SEGIS in the Scottish Executive, no specific training and only basic GIS skills are required to integrate this useful presentational and analytical tool to our many and varied social research projects.
February 12, 2007
Geographic Information System (GIS) is a computer based information system used to digitally represent and analyse the geographic features present on the Earth’ surface and the events (non-spatial attributes linked to the geography under study) that taking place on it. The meaning to represent digitally is to convert analog (smooth line) into a digital form.
“Every object present on the Earth can be geo-referenced”, is the fundamental key of associating any database to GIS. Here, term ‘database’ is a collection of information about things and their relationship to each other, and ‘geo-referencing’ refers to the location of a layer or coverage in space defined by the co-ordinate referencing system.
Work on GIS began in late 1950s, but first GIS software came only in late 1970s from the lab of the ESRI. Canada was the pioneer in the development of GIS as a result of innovations dating back to early 1960s. Much of the credit for the early development of GIS goes to Roger Tomilson. Evolution of GIS has transformed and revolutionized the ways in which planners, engineers, managers etc. conduct the database management and analysis.