March 2001

Release date: 21 March, 2001 Three NUI Galway Researchers Honoured for Excellence in Erosion and Sediment Control Three National University of Ireland, Galway (NUI, Galway) researchers have been honoured for excellence in natural resource conservation and environmental protection. The researchers measured the amount of erosion resulting from sheep grazing peat hillsides in western Ireland. Rain can wash sediment from such erosion into streams, threatening water quality and spawning grounds of wild Atlantic salmon. John Mulqueen, of Teagasc, who is based in the University and Michael Rodgers and Niall Marren, of NUI, Galway s Civil Engineering Department, describe their findings in a technical paper, Erosion of Hill Peat in Western Ireland. Their paper has received the 2001 Most Distinguished Technical Paper Award, from the International Erosion Control Association (IECA). Dr. Michael Rodgers accepted the award on behalf of all three researchers during formal ceremonies at the recent 2001 IECA conference in Las Vegas, Nevada, Nearly 2000 erosion control professionals from around the world attended the conference. The award is made to a scientific paper that contributes most to advancing erosion control knowledge and also recognises concise, clear technical writing, which presents innovative solutions to erosion control problems. The NUI, Galway research, the first of its kind involving peat hillsides, was prompted by concerns that increased stocking rates of sheep could accelerate erosion. Grazing by more sheep could remove too much soil-protecting vegetation and increased foot treading on paths could loosen the peat soils, leaving them more vulnerable to the erosive impact of raindrops and to runoff. The two-year field study involved an 8-hectare Leenane subcatchment of the Erriff River on a Teagasc research farm at Glendavock townland (Co. Mayo). Many slopes on the farm have gradients of 9% to 18%. Average annual rainfall, about 2,500 mm, is among the highest in Ireland. In addition to the field studies at Leenane, the researchers conducted laboratory tests on undisturbed slabs of peat from Leenane and three other sites at Maam, Croagh Patrick and Newport at the Environmental Engineering and Soil Mechanics Laboratories at NUI, Galway. In the laboratory tests the researchers varied the slope and simulated the type of soil disturbance caused by sheep traffic. They found that annual peat sediment losses at the Leenane hill farm averaged 278 kg per hectare with a stocking rate of 0.9 Scottish Blackface ewes per hectare. In the laboratory trials, the virgin peats at Leenane and Maam were very resistant to erosion, while virgin peats from both Newport and Croagh Patrick were erodible. According to the researchers, this study suggests that overstocking, primarily through excessive sheep traffic damaging the peat and weathering of shallow peat, increases the likelihood of erosion. Removal of vegetation, per se, by grazing has less impact on erosion because of the strength of the peat's fibrous top layer.For hill peat farming, the sustainable sheep-stocking rate depends on the proportion and strategic use of greenland available. Under the management system at Leenane, this stocking rate is 0.9 ewes per hectare. To reduce erosion, sheep access areas and corridors should be changed from time to time. If heavily treaded with little vegetation, these areas should be fenced off to allow for recovery of the peat surface and re-establishment of vegetation. The research was financed, in part, by European Union Structural Funding through Teagasc. The IECA, founded in 1972, is a non-profit professional organisation, with members in 56 countries around the world who are dedicated to minimising accelerated soil erosion. This is the tenth year of the annual IECA Environmental Excellence Awards programme. Ends Information from: Máire Mhic Uidhir, Press Officer, NUI, Galway. Tel. 091 750418

Release date: 12 March, 2001 Ultra-fast laser facility puts Galway Centre at thecutting edge of Technology The National Centre for Laser Applications (NCLA) NUI, Galway has just opened a new state-of-the-art laser processing facility. The new laboratory is built around a femto-second laser system, supplied by Clark MXR of the US. This is only one of four similar systems installed in laboratories around Europe and places the NCLA at the forefront of the new science of ultra-fast laser processing of materials. "This new laser will allow us to provide this cutting-edge technology to Irish companies for the first time", according to Dr Gerard O Connor, manager of the NCLA. "The first industrial research project based on this new technology has just been agreed between the NCLA and a leading global manufacturer of micro-components." The NCLA is Ireland s centre of excellence in laser technology, working closely with Irish industry on the development of new production tools and techniques based on laser and optical systems. Laser technology is successfully employed in a large number of industries, from drilling and cutting of engineering materials, to precision marking and welding of advanced polymers. "Lasers are also a key enabling technology in the automation of high precision industrial processes, " explains Dr. O Connor. "Many Irish companies, both indigenous and multi-national, in sectors ranging from electronics to medical devices, benefit significantly from the improved product quality, greater efficiency and higher throughput, which laser tooling can provide". The medical device manufacturing sector is one of the most active in the uptake of laser technology and the NCLA provides much support in terms of research and development services to this sector and runs a successful conference each year for this industry. Galway is now acknowledged as the European Centre for medical device manufacturing, with many thousands employed in companies such as Boston Scientific and Medtronic AVE. Femto-second lasers are an exciting new technology in the field of materials processing applications. "The technology is based on the generation of a stream of extremely short, high intensity light pulses, each lasting for only a few hundred femto-seconds. (A femto-second is equal to 10-15 of a second, or a million-billionth of a second!)," explains Dr. O Connor. "The key benefits of such ultra-short pulses lie in their ability to deposit energy into materials in a very short time interval, offering significant advantages over conventional laser sources in high-precision applications such as micro-machining, micro-drilling and ultra-precise cutting." Materials processing with femto-second lasers is also largely independent of the optical properties of the material, which opens up the possibility of processing transparent materials like glasses and highly reflective and conductive materials such as aluminium and copper which have traditionally been unsuitable for laser machining. "Femto-second lasers are facilitating 21st century advances in science and technology, enabling the machining of the smallest precision features in biological and man-made materials," according to Dr. Jonathan Magee, a senior engineer at the NCLA. As the energy is transferred from the laser beam into the material, the temperature of the material rises rapidly above its boiling point, where it vapourises. This process is called ablation. "With conventional laser processing techniques, the heat is conducted quickly away from the absorption region before ablation occurs, leading to melting of the material over a larger area. This results in a lower precision and quality of the laser processed parts," says Dr. Magee. The femtosecond system located at NUI, Galway consists of three laser sources in a single table-top system. These lasers are referred to as the semiconductor seed laser, the YAG pump laser and the titanium-sapphire amplifier laser. The system will deliver up to one thousand ultra-short pulses per second and the duration of the pulse can be varied from 180 to 1000 femtoseconds. "This is an exciting development for the NCLA and we look forward to giving many Irish companies the opportunity to develop new products and processes using this new facility" says Dr. O Connor. Ends Information from: Máire Mhic Uidhir, Press Officer, Tel. 091 750418