During West-Greenland summers, icebergs up to 200 metres high float into the sea while glaciers speed up to 30 metres per day. (Photo: WikiCommons)
Estimates of the current loss of land ice in Greenland vary between 130 and 230 cubic kilometres of water per year. The controversy rages even within the TU’s faculty of Aerospace Engineering.
“The present day climate is too hot for Greenland,” says Dr Ernst Schrama, a remote sensing veteran with a track record at Nasa who recently gave a lecture at the faculty of Civil Engineering Geosciences. Schrama showed results of the Grace satellites orbiting the Earth, mapping variations in gravity and thus in mass. The data required advanced filtering techniques and educated interpretation, but ultimately Schrama presented a mass loss of 200 gigatonnes per year for Greenland. And worse: the ice loss accelerates by 10 percent each year. Together with colleagues from the University of Utrecht and the Royal Netherlands Meteorological Institute, Schrama published these results last year November in Science. Continued…
Posted in Articles, Delta.
Tagged with Climate change, GRACE, Greenland, land ice.
By admin
– december 2, 2010
Layers of quantum dots can be used as solar cells. Better connections between the dots are needed however to boost the efficiency.
Ilustration: Elise Talgorn
They come in all colours. Nano-sized semiconductor crystals, endearingly called quantum dots or q-dots, manifest properties between those of molecular matter and bulk material. The reason is that an electron in a q-dot experiences quantum confinement. This results in discrete steps between energy states (bandgaps), which depend on the material as well as the size. Hence, by varying the size of the q-dots one can tune them to a specific colour, rendering them interesting candidates for use in solar cells. Continued…
Posted in Articles, Delta.
Tagged with q-dots, quantumdots, solar cell.
By admin
– november 25, 2010
Squeezing, rolling, wiggling – the things people do when they are stressed. Now here’s a pen that not only knows when people are stressed but also relaxes them.
Empathic technology, devices that know how you feel and act correspondingly, is the next big thing in man-machine interaction. Already there are cars that give feedback on your driving style, or alarm clocks that wait to ring until the person moves. PhD researcher Miguel Bruns Alonso (Industrial Design) now wants to take this concept one step further: devices that interact subconsciously with the user. As a contrasting example, he mentions the anti-RSI computer programme, Workpace, which simply tells people when to relax or might temporarily block your work in progress for your own well-being. “It’s so in your face,” Bruns says. Continued…
Posted in Articles, Delta.
Tagged with empathic technology, haptic pen.
By admin
– november 25, 2010
The electro-osmotic pump transports fluid through the central axis between the greenish silver electrodes. Bypasses are needed to prevent blockage by entrapped air bubbles (Photo: Friedjof Heuck)
The micropipette can deliver fog droplets of liquid to molecule-sized targets. Pharmaceutical labs are following the developments with great interest.
“It’s not a world record, but it’s definitely one of the smallest pumps ever made,” says Dr Friedjof Heuck, of the microscopic pump he developed at Dimes. German-born Heuck followed his professor, Urs Staufer, from Switzerland to Delft three years ago. Prof. Staufer (Mechanical, Maritime and Materials Engineering) wanted to extend the scanning force microscope (a device that scans surfaces with resolution in the nanometre range) with a micropipette, including a pump and electrodes. After three years, Dr Heuck has succeeded in constructing an electric pump that measures only 40 microns across (one half of a hair). The active part is even thinner, about a tenth of a hair, and pumps 35 picolitre (a millionth of a millionth litre) per second – it would need nine centuries to pump a litre. Continued…
Posted in Articles, Delta.
Tagged with micropipette, scanning force microscope, SFM.
By admin
– november 18, 2010
The eruption of the Eyjafjallajökull last spring was unusual in all respects. Geophysicist Dr Andy Hooper analysed the events in pursuit of better understanding.
Dr Andy Hooper experiences the early phases of the Eyjafjallajökull eruption (Photo: Sigrún Hreinsdóttir)
Last spring, whilst air traffic across the Atlantic Ocean was shut down due to an Icelandic volcano spewing ashes out into the atmosphere, high overhead the TerraSAR-X satellite silently passed by, taking its regular readings, as it had been doing for nearly a year up to that point. In taking fresh measurements every 11 days, the satellite’s imaging radar had shown how the slopes of the Eyjafjallajökull (‘Island Mountain Icecap’) had risen by several centimetres prior to the eruption on its flank on 20 March 2010. Continued…
Posted in Articles, Delta.
Tagged with Iceland, radar interferometry, volcano.
By admin
– november 18, 2010
Loud telephone calls are the number one irritation in trains. The first-ever Dutch lip reader might provide a solution: silent speech or mute miming.
If a talking mouth is all there is on the screen, the automated lip reader that Dr Alin Chitu has developed even beats experienced human lip readers. However, as soon as the image widens, humans win hands down. Context is perhaps the most important factor for humans in visual speech recognition. You needn’t be especially gifted to understand the request for a ‘Biertje?’ in a crowded, noisy bar. Continued…
Posted in Articles, Delta.
Tagged with communication, deaf, lip reading, mobile phones.
By admin
– november 11, 2010
After years of protests from residents against Shell’s plan to inject 400,000 tonnes of compressed CO2 under a local shopping mall, the plan was finally scrapped last week by the new Dutch minister of economic affairs, Maxime Verhagen.
On Thursday, 4 November, Minister Maxime Verhagen informed the Dutch House of Representatives that the proposed CO2 sequestration project in Barendrecht would be stopped due to a ‘complete lack of local support’, as well as a delay of more than three years in obtaining permits. Nature carried the story on its website. Continued…
Posted in Articles, Delta.
Tagged with Barendrecht, CCS, CO2.
By admin
– november 11, 2010
Deok-je Bang next to the 10 kW prototype of his direct-drive generator (Photo: Bong-jun Kim)
Scaling up wind turbines from the current 3 megawatts to 5, 10 or even 20 megawatts demands daring and creative concepts. Dr Deok-je Bang presented some in his thesis.
To harvest more power from the wind, you need to build monstrously large devices. A 10 megawatt (MW) wind turbine would need a blade diameter as large as the Euromast. Mounted on its support mast, it would actually dwarf that Rotterdam monument. Continued…
Posted in Articles, Delta.
Tagged with wind turbines.
By admin
– november 4, 2010
By lowering the EPC energy performance coefficient, the government aims to reduce energy use by buildings. Dr Olivia Guerra Santín has shown however that the EPC barely works.
“It’s very tempting to think that by simply lowering a figure you can control the energy aspects of newly built housing,” says Professor Henk Visscher (OTB), who lectures on housing quality and process innovation. The reality however is that there are other factors in play, such as building quality and differences between households (which can vary up to a factor of 2).
Continued…
Posted in Articles, Delta.
Tagged with energy conservation, EPC, housing.
By admin
– november 4, 2010
Water jets at various pressures drilled into a human heel bone. Higher-pressure jets tend to make smaller holes. (Photo: Steven den Dunnen)
High-pressure water jets might be just the tools orthopaedic surgeons need. Biomechanical engineers have started working on their development.
Some things have to get worse before they get better. Take for instance local injuries to knee cartilage, which are treated by removing the damaged tissue, followed by hammering a series of 3-millimetre holes into the bone’s head. This treatment, devised by Dr Richard Steadman in 1981, is based on the healing properties of the ensuing blood and bone marrow cells, which form a secondary cartilage layer within about a week’s time. The trouble though is that hammering holes is not a very precise procedure. Continued…
Posted in Articles, Delta.
Tagged with orthopaedics; water-jet; biomechanics.
By admin
– oktober 14, 2010
