New program will join MIT's global network of supply chain centers.
MIT's Center for Transportation and Logistics (MIT-CTL) and LOGyCA, a Colombia-based logistics company, have signed an agreement worth $19 million creating the Center for Latin-American Logistics Innovation (CLLI), the leading research and education center for supply chain and logistics in Latin America.
CLLI will join MIT-CTL and the Zaragoza Logistics Center in Spain as the third member of MIT's growing international network of centers dedicated to supply chain education and research that now spans the United States, Europe and Latin America.
CLLI will help Latin American businesses and individuals compete in local, regional and global markets by delivering leading-edge research, technology and educational programs in logistics, transportation and supply chain management. The Center will also become a major force in academia within Latin America and across the globe.
LOGyCA, which boasts the most robust supply chain technology infrastructure in the region, will house the CLLI in its Bogota, Colombia, headquarters. CLLI researchers and students will have access to the infrastructure and knowledge base that helped Colombia establish the largest collaborative technology platform in Latin America.
CLLI will also connect with its counterparts in the United States through MIT-CTL in Cambridge, MA, and in Europe through the Zaragoza Logistics Center (ZLC) in Spain. The partnership between MIT-CTL and ZLC, launched in 2003, has created a highly regarded educational program and continues to play a key role in the economic growth of the Aragon region and the success of the PLAZA Logistics Park in Zaragoza.
MIT Professor of Engineering Systems and Director of MIT-CTL Yossi Sheffi said that launching the CLLI extends the reach of both MIT-CTL and the ZLC, and enhances their ability to meet the ever-growing demand for truly global supply chain education and research programs.
"Globalization continues to bring new opportunities for growth - and immense challenges. To stay on the cutting edge and help companies keep pace with these changes, we are expanding our unique network of learning centers where faculty, students, researchers and companies across continents collaborate on supply chain and logistics projects that have global impact," said Sheffi, who is also Director of the MIT Engineering Systems Division.
Rafael Florez, Director of LOGyCA, said the creation of CLLI is an excellent opportunity to strengthen the development of Colombian and Latin American logistics, a well-known strategic component of competitiveness.
"By joining the MIT-CTL network, CLLI will actively participate in the development of global educational and research programs. It will also give CLLI the opportunity to develop solutions that reflect the unique logistics and supply chain challenges in our economies. Latin American business leaders will have access to world-class academic programs that will contribute to improving value chains through the continent. This has always been LOGyCA's mission: leadership in innovation for value networks," said Florez.
The partnership between MIT-CTL and LOGyCA is based on a 10-year agreement, which officially begins on March 1, 2008. The $19-million deal includes a $4 million gift from LOGyCA to the MIT Center for Transportation & Logistics.
Sunday, February 3, 2008
River plants may play major role in health of ocean coastal waters
Aquatic plants in rivers and streams may play a major role in the health of large areas of ocean coastal waters, according to recent research from MIT's Department of Civil and Environmental Engineering.
This work, which appeared in the Dec. 25 issue of the Journal of Fluid Mechanics (JFM), describes the physics of water flow around aquatic plants and demonstrates the importance of basic research to environmental engineering. This new understanding can be used to guide restoration work in rivers, wetlands and coastal zones by helping ecologists determine the vegetation patch length and planting density necessary to damp storm surge, lower nutrient levels, or promote sediment accumulation and make the new patch stable against erosion.
Professor Heidi Nepf, a MacVicar Faculty Fellow, was principal investigator on the research. Brian White, a former graduate student at MIT who is now an assistant professor at the University of North Carolina, was co-author with Nepf of the JFM paper. Marco Ghisalberti, a postdoctoral associate at the University of Western Australia, worked with Nepf on some aspects of this research when he was an MIT graduate student. This work was supported by grants from the National Science Foundation.
Traditionally, people have removed vegetation growing along rivers to speed the passage of waters and prevent flooding, but that practice has changed in recent years. Ecologists now advocate replanting, because vegetation provides important habitat. In addition, aquatic plants and the microbial populations they support remove excess nutrients from the water. The removal of too many plants contributes to nutrient overload in rivers, which can subsequently lead to coastal dead zones--oxygen-deprived areas of coastal water where nothing can survive. One well-documented dead zone in the Gulf of Mexico, fed by nutrient pollution from the Mississippi River, grows to be as large as the state of New Jersey every summer.
Nepf's work, which describes how water flows into and through a plant canopy and how long it remains within the canopy, can be used to find the right balance between canopy and flow in a river.
Vegetation generates resistance to flow, so the velocity within a canopy is much less than the velocity above it. This spatial gradient of velocity, or shear, produces a coherent swirl of water motion, called a vortex. Using scaled physical models, Nepf and Ghisalberti described the dynamic nature of these vortices and developed predictive models for canopy flushing that fit available field observations. The team showed that vortices control the flushing of canopies by controlling the exchange of fluid between the canopy and overflowing water. Similar vortices also form at the edge of a vegetated channel, setting the exchange between the channel and the vegetation.
The structure and density of the canopy controls the extent to which flow is reduced in the canopy and also the water-renewal time, which ranges from minutes to hours for typical submerged canopies. These timescales are comparable to those measured in much-studied underground hyporheic zones, suggesting that channel vegetation could play a role similar to these zones in nutrient retention. In dense canopies, the larger vortices cannot penetrate the full canopy height. Water renewal in the lower canopy is controlled by much smaller turbulence generated by individual stems and branches.
"We now understand more precisely how water moves through and around aquatic canopies, and know that the vortices control the water renewal and momentum exchange," said Nepf. "Knowing the time scale over which water is renewed in a bed, and knowing the degree to which currents are reduced within the beds helps researchers determine how the size and shape of a canopy will impact stream restoration."
This work, which appeared in the Dec. 25 issue of the Journal of Fluid Mechanics (JFM), describes the physics of water flow around aquatic plants and demonstrates the importance of basic research to environmental engineering. This new understanding can be used to guide restoration work in rivers, wetlands and coastal zones by helping ecologists determine the vegetation patch length and planting density necessary to damp storm surge, lower nutrient levels, or promote sediment accumulation and make the new patch stable against erosion.
Professor Heidi Nepf, a MacVicar Faculty Fellow, was principal investigator on the research. Brian White, a former graduate student at MIT who is now an assistant professor at the University of North Carolina, was co-author with Nepf of the JFM paper. Marco Ghisalberti, a postdoctoral associate at the University of Western Australia, worked with Nepf on some aspects of this research when he was an MIT graduate student. This work was supported by grants from the National Science Foundation.
Traditionally, people have removed vegetation growing along rivers to speed the passage of waters and prevent flooding, but that practice has changed in recent years. Ecologists now advocate replanting, because vegetation provides important habitat. In addition, aquatic plants and the microbial populations they support remove excess nutrients from the water. The removal of too many plants contributes to nutrient overload in rivers, which can subsequently lead to coastal dead zones--oxygen-deprived areas of coastal water where nothing can survive. One well-documented dead zone in the Gulf of Mexico, fed by nutrient pollution from the Mississippi River, grows to be as large as the state of New Jersey every summer.
Nepf's work, which describes how water flows into and through a plant canopy and how long it remains within the canopy, can be used to find the right balance between canopy and flow in a river.
Vegetation generates resistance to flow, so the velocity within a canopy is much less than the velocity above it. This spatial gradient of velocity, or shear, produces a coherent swirl of water motion, called a vortex. Using scaled physical models, Nepf and Ghisalberti described the dynamic nature of these vortices and developed predictive models for canopy flushing that fit available field observations. The team showed that vortices control the flushing of canopies by controlling the exchange of fluid between the canopy and overflowing water. Similar vortices also form at the edge of a vegetated channel, setting the exchange between the channel and the vegetation.
The structure and density of the canopy controls the extent to which flow is reduced in the canopy and also the water-renewal time, which ranges from minutes to hours for typical submerged canopies. These timescales are comparable to those measured in much-studied underground hyporheic zones, suggesting that channel vegetation could play a role similar to these zones in nutrient retention. In dense canopies, the larger vortices cannot penetrate the full canopy height. Water renewal in the lower canopy is controlled by much smaller turbulence generated by individual stems and branches.
"We now understand more precisely how water moves through and around aquatic canopies, and know that the vortices control the water renewal and momentum exchange," said Nepf. "Knowing the time scale over which water is renewed in a bed, and knowing the degree to which currents are reduced within the beds helps researchers determine how the size and shape of a canopy will impact stream restoration."
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