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Showing posts with label CIVIL ENGINEERING. Show all posts
Showing posts with label CIVIL ENGINEERING. Show all posts

Switching to vehicles powered by electricity from renewables could save lives - Video

Written By Unknown on Saturday, January 31, 2015 | 5:20 AM

Use of corn ethanol or electricity from coal worse than gasoline for public health
Driving vehicles that use electricity from renewable energy instead of gasoline could reduce the resulting deaths due to air pollution by 70 percent. This finding comes from a new life cycle analysis of conventional and alternative vehicles and their air pollution-related public health impacts, published Monday, Dec. 15, 2014, in the Proceedings of the National Academy of Sciences.

The study also shows that switching to vehicles powered by electricity made using natural gas yields large health benefits. Conversely, vehicles running on corn ethanol or vehicles powered by coal-based or "grid average" electricity are worse for health; switching from gasoline to those fuels would increase the number of resulting deaths due to air pollution by 80 percent or more.

“These findings demonstrate the importance of clean electricity, such as from natural gas or renewables, in substantially reducing the negative health impacts of transportation,” said Chris Tessum, co-author on the study and a researcher in the Department of Civil, Environmental, and Geo- Engineering in the University of Minnesota’s College of Science and Engineering.

The University of Minnesota team estimated how concentrations of two important pollutants—particulate matter and ground-level ozone—change as a result of using various options for powering vehicles. Air pollution is the largest environmental health hazard in the U.S., in total killing more than 100,000 people per year. Air pollution increases rates of heart attack, stroke, and respiratory disease.

The authors looked at liquid biofuels, diesel, compressed natural gas, and electricity from a range of conventional and renewable sources. Their analysis included not only the pollution from vehicles, but also emissions generated during production of the fuels or electricity that power them. With ethanol, for example, air pollution is released from tractors on farms, from soils after fertilizers are applied, and to supply the energy for fermenting and distilling corn into ethanol.

“Our work highlights the importance of looking at the full life cycle of energy production and use, not just at what comes out of tailpipes,” said Bioproducts and Biosystems Engineering Assistant Professor Jason Hill, co-author of the study. “We greatly underestimate transportation’s impacts on air quality if we ignore the upstream emissions from producing fuels or electricity.”

The researchers also point out that whereas recent studies on life cycle environmental impacts of transportation have focused mainly on greenhouse gas emissions, it is also important to consider air pollution and health. Their study provides a unique look at where life cycle emissions occur, how they move in the environment, and where people breathe that pollution. Their results provide unprecedented detail on the air quality-related health impacts of transportation fuel production and use.
“Air pollution has enormous health impacts, including increasing death rates across the U.S.,” said Civil, Environmental and Geo- Engineering Associate Professor Julian Marshall, co-author on this study. “This study provides valuable new information on how some transportation options would improve or worsen those health impacts.”
The study’s authors are Marshall and Tessum (College of Science and Engineering) and Hill (College of Food, Agricultural and Natural Resource Sciences), at the University of Minnesota. Marshall and Hill are also Resident Fellows of the University’s Institute on the Environment. This research was supported by the University of Minnesota’s Initiative for Renewable Energy and the Environment (IREE), the Office of Energy Efficiency & Renewable Energy of the U.S. Dept. of Energy (EERE/DOE), and the Agricultural and Food Research Initiative of the U.S. Dept. of Agriculture (USDA/AFRI).

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Source: University of Minnesota

New technology may identify tiny strains in body tissues before injuries occur

Written By Unknown on Friday, January 16, 2015 | 9:13 PM

The top image shows how the new algorithm is able to identify an area (in red) where stress has created a weak spot in a small piece of plastic wrap. The older method (shown in the bottom half of the picture) is unable to pinpoint the place where the plastic wrap is weakening.
Credit: John Boyle, © The Royal Society (used with permission)
Researchers at Washington University in St. Louis have developed algorithms to identify weak spots in tendons, muscles and bones prone to tearing or breaking. The technology, which needs to be refined before it is used in patients, one day may help pinpoint minor strains and tiny injuries in the body's tissues long before bigger problems occur.

The research is available online Aug. 27 in the Journal of the Royal Society Interface, which publishes research at the nexus of the physical and life sciences.

"Tendons are constantly stretching as muscles pull on them, and bones also bend or compress as we carry out everyday activities," said senior investigator Stavros Thomopoulos, PhD, professor of orthopaedic surgery. "Small cracks or tears can result from these loads and lead to major injuries. Understanding how these tears and cracks develop over time therefore is important for diagnosing and tracking injuries."

To that end, Thomopoulos and his colleagues developed a way to visualize and even predict spots where tissues are weakened. To accomplish this, they stretched tissues and tracked what happened as their shapes changed or became distorted.

The paper's first author, John J. Boyle, a graduate student in biomedical engineering, combined mechanical engineering fundamentals with image-analysis techniques to create the algorithms, which were tested in different materials and in animal models.

"If you imagine stretching Silly Putty or a swimming cap with a picture on it, as you pull, the picture becomes distorted," Boyle said. "This allows us to track how the material responds to an external force."

In one of the experiments described in the paper, Boyle sprayed a pattern of dots on plastic wrap, stretched it and tracked the dots.

"As you pull and stretch the plastic wrap, eventually tears begin to emerge," he explained. 

"The new algorithm allowed us to find the places where the tears were beginning to form and to track them as they extended. Older algorithms are not as good at finding and tracking localized strains as the material stretches."

In fact, one of the two new algorithms is 1,000 times more accurate than older methods at quantifying very large stretches near tiny cracks and tears, the research showed. And a second algorithm has the ability to predict where cracks and failures are likely to form.

"This extra accuracy is critical for quantifying large strains," said Guy Genin, PhD, professor of mechanical engineering and co-senior investigator on the study. "Commercial algorithms that estimate strain often are much less sensitive, and they are prone to detecting noise that can arise from the algorithm itself rather than from the material being examined. The new algorithms can distinguish the noise from true regions of large strains."

Thomopoulos, who also is a professor of biomedical engineering and of mechanical engineering, works with Genin to study the shoulder's rotator cuff, a group of tendons and muscles that connect the upper arm to the shoulder blade. They want to learn why some surgeries to repair rotator cuff injuries ultimately fail. Their goal is to increase the odds that the tissue in the shoulder will heal following surgery, and they believe the new algorithms could help them get closer to that goal.

How soon the new algorithms could be used in patients depends on getting better images of the body's tissues. Current imaging techniques, such as MRI and ultrasound, lack the required clarity and resolution.

Genin also explained that although the goal of the current study is to better understand how forces at work on human tissue cause injury and stress, the algorithms also could help engineers identify vulnerable parts of buildings and other structures. Our muscles and bones, he said, are influenced by the same strains that affect those structures.

"Whether it's a bridge or a tendon, it's vital to understand the ways that physical forces cause structures and tissues to deform so that we can identify the onset of failures and eventually predict them," he said.

In the long run, they want to use the algorithms to prevent additional injuries following surgery to repair knees, shoulders and other tissues. They also said it may be possible some day to predict problems before they occur.

The group, which applied for a provisional patent earlier this year, hopes the algorithms will be useful to researchers in the medical and engineering fields.

As a piece of plastic wrap is stretched, the new algorithms identify the location (in red) where it is weakening, which is where the material eventually breaks.

High-intensity sound waves may aid regenerative medicine

Written By Unknown on Thursday, January 15, 2015 | 6:03 PM

This is a cross section through a histotripsy lesion created in bovine liver tissue with the liquified cellular contents washed out revealing the remaining extracellular matrix. The scale bar represents 5mm. Credit: T.Khoklova/UW
Researchers at the University of Washington have developed a way to use sound to create cellular scaffolding for tissue engineering, a unique approach that could help overcome one of regenerative medicine's significant obstacles. The researchers will present their technique at the 168th meeting of the Acoustical Society of America (ASA), held October 27-31, 2014, at the Indianapolis Marriott Downtown Hotel.

The development of the new technique started with somewhat of a serendipitous discovery. The University of Washington team had been studying boiling histotripsy -- a technique that uses millisecond-long bursts of high-intensity ultrasound waves to break apart tissue -- as a method to eliminate cancerous tumors by liquefying them with ultrasound waves. After the sound waves destroy the tumors, the body should eliminate them as cellular waste. When the researchers examined these 'decellularized' tissues, however, they were surprised by what the boiling left intact.

"In some of our experiments, we discovered that some of the stromal tissue and vasculature was being left behind," said Yak-Nam Wang, a senior engineer at the University of Washington's Applied Physics Laboratory. "So we had the idea about using this to decellularize tissues for tissue engineering and regenerative medicine."

The structure that remains after decellularizing tissues is known as the extracellular matrix, a fibrous network that provides a scaffold for cells to grow upon. Most other methods for decellularizing tissues and organs involve chemical and enzymatic treatments that can cause damage to the tissues and fibers and takes multiple days. Histrostipsy, on the other hand, offers the possibility of fast decellularization of tissue with minimal damage to the matrix.

"In tissue engineering, one of the holy grails is to develop biomimetic structures so that you can replace tissues with native tissue," Wang said. Stripping away cells from already developed tissue could provide a good candidate for these structures, since the extracellular matrix already acts as the cellular framework for tissue systems, Wang said.

Due to its bare composition, the matrix also induces only a relatively weak immune response from the host. The matrix could then theoretically be fed with stem cells or cells from the same person to effectively re-grow an organ.

"The other thought is that maybe you could just implant the extracellular matrix and then the body itself would self-seed the tissues, if it's just a small patch of tissue that you're replacing," Wang said. "You won't have any immune issues, and because you have this biomimetic scaffold that's closer to the native tissue, healing would be better, and the body would recognize it as normal tissue."

Wang is currently investigating decellularization of kidney and liver tissue from large animals. Future work involves increasing the size of the decellularized tissues and assessing their in-vivo regenerative efficacy.

First study of 'Golden Age' mandolins unlocks secrets of their beauty

Written By Unknown on Wednesday, January 14, 2015 | 7:24 PM

Mandolins made by G. Filano 1765 (a), A. Vinaccia 1785 (b), G.B. Fabricatore 1789 (c) and G. Gagliano 1799 (d). Credit: Image courtesy of Springer Science+Business Media
Analyzing varnishes and decorations could provide a new way to identify mandolin "Old Masters."

Some of the most elaborately decorated instruments in history were produced in 18th century Naples. The materials for varnishes and decorations used by individual mandolin masters, honed for wealthy clients in the ancient city's labyrinthine artisan quarter, have been kept secret for over 200 years. Details are disclosed for the first time by Tommaso Rovetta from the Universitร  degli Studi di Pavia and colleagues at the Laboratorio Arvedi Research Group in Springer's journal Applied Physics A -- Materials Science & Processing.

Italian conservation scientists studied ten instruments from some of the most important dynasties of the "Golden Age" of Neapolitan mandolins. Advanced high-resolution imaging techniques shed light on some of the most jealously guarded decorative secrets and could provide a new way to accurately identify mandolins from specific workshops.

The Neapolitan mandolin was set apart by the deeper bowl of its body, producing a more resonant sound heard in works by Beethoven and Verdi. The style was developed by the Vinaccia family and adopted by other leading luthiers such as the Filano, Fabricatore and Gagliano families.

The scientists obtained mandolins from each of these makers courtesy of the National Museum of Musical Instruments in Rome and a private collector. Given their rarity and excellent state of conservation, only microscopic samples could be analysed from already-damaged areas. Nevertheless, the team was able to see that different workshops used different techniques and materials to achieve the same aesthetic effect.

"For mandolins of unknown origin, our results could represent a new way to identify where they were made and therefore their historic and economic value," says Tommaso Rovetta.

In particular, the resin used between patterns of pearl, ivory, bone or possibly horn around the sound hole contain a mixture unique to each workshop. Shellac, a resin from the lac beetle popular today in nail varnish, seems to be the only substance which formed a common base to which pigments and minerals were added. In a 1796 Fabricatore, a mineral found only in the volcanic lavas of Mount Vesuvius was detected. The mixtures in Vinaccia instruments were particularly complex and the scientists were surprised to find the fossilised remains of diatoms, a type of algae.

"We assume there were intense exchanges of technical know-how between masters and their apprentices but, with no written records, this knowledge was taken to the grave," says Rovetta. "We hope the rediscovery of ancient recipes will provide inspiration to today's luthiers."

‘Fury’ tanks in safe hands

Written By Unknown on Sunday, January 11, 2015 | 7:10 PM

Fury Sherman. Credit: Image courtesy of Bournemouth University
BU research engineers have been working on military vehicles that feature in Brad Pitt's new movie.

Set in the Second World War and currently in UK cinemas, 'Fury' sees Pitt's character Wardaddy command a Sherman tank.

Scenes from the movie were filmed at the Tank Museum at Bovington, where the BU research team are investigating how to preserve these historic vehicles.

The team have worked on the Sherman and Tiger 1, which can be seen in the Fury movie trailer (2 minutes 26 seconds in). Researchers Adil Saeed, Dr Zulfiqar Khan, and Professor Mark Hadfield from BU's Sustainable Design Research Centre have published widely on these particular vehicles.

Dr Zulfiqar Khan said, "This movie reflects the importance of the research, which examines how we can preserve these vehicles for the benefit of society for lengths of time that far exceed the basis any normal design intent.

"The centenary of the First World War and the passing of the generation that fought in the Second World War, means the conservation of significantly degraded vehicle collections has taken on a new importance."

The Tank Museum at Bovington is one of the largest military vehicle museums in the world, boasting a collection of over 300 military vehicles with historic significance. Structural deterioration through corrosion, corrosion fatigue, stress corrosion cracking and mechanical failures are a threat to these vehicles in terms of conservation.

The only operational Tiger tank in the world is currently at The Tank Museum at Bovington. This and other vehicles had to be conserved sustainably, while operating modestly for the annual Tank Fest and other events.

Dr Khan concluded, "The opportunity of collaborative research with The Tank Museum at Bovington to develop sustainable methodology of conserving historic military tanks brought us face to face with the history. This research investigated the state of the structural integrity of vehicles used in WW1, WW2 and post war.

"The outcomes of the research informed the current design of control environment in The Tank Museum. In addition a separate research project looked into the cost implications of project management of The Tank Museum.

"This kind of activity is important in engaging new generations with science, technology, maths and mechanical engineering design solutions."

The research has led to further collaborations with Defence Science & Technology Laboratory Ministry of Defence to develop corrosion condition monitoring and predictive modelling techniques.

What's in the grime tarnishing the Taj Mahal?

Written By Unknown on Thursday, January 8, 2015 | 8:51 AM

Taj Mahal
Every several years, workers apply a clay mask to India's iconic but yellowing Taj Mahal to remove layers of grime and reveal the white marble underneath. Now scientists are getting to the bottom of what kinds of pollutants are discoloring one of the world's celebrated wonders. Their findings, published in the ACS journal Environmental Science & Technology, could help inform efforts to protect the mausoleum and other surfaces from pollution.

Mike H. Bergin, Sachchida Nand Tripathi and colleagues note that Indian officials have tried to reduce the effects of pollution on the Taj Mahal by restricting nearby traffic and limiting local industrial emissions. But despite regulations and an occasional deep clean, the domes and minarets continue to accrue a layer of soot. So far, no published studies have looked closely at what specific compounds are causing it to appear yellow. Bergin's and Tripathi's teams wanted to find out.

The researchers analyzed particles in the air and on marble samples near the main dome over several months. Using a novel method they developed, the team estimated how these specks reflect light and therefore affect the color of the building. They conclude that black carbon and brown carbon from the burning of trash, fuels and other materials are among the primary pollutants tarnishing the Taj Mahal. In the future, their approach could be used to craft strategies to address the chronic yellowing and improve air quality, they say.

The authors acknowledge funding from the Indo-U.S. Science and Technology Forum, the Environmental Protection Agency and the National Science Foundation.

Better dam planning strategies

This is a map showing combined effect of current and future dams. Credit: McGill University
When dams are built they have an impact not only on the flow of water in the river, but also on the people who live downstream and on the surrounding ecosystems. By placing data from close to 6,500 existing large dams on a highly precise map of the world's rivers, an international team led by McGill University researchers has created a new method to estimate the global impacts of dams on river flow and fragmentation.

Among their findings, published online today in Environmental Research Letters: 48% of the world's river volume is moderately or severely affected by dams today -- and that figure would nearly double if all dams planned or under construction are completed in the future.
"Over the past 60 years, a myriad of dams have been built either to provide hydroelectric power, or for irrigation purposes, or as flood protection," says Bernhard Lehner, a professor in McGill University's Department of Geography and the research director of the project. "The construction of large dams then slowed down for the last 20 years as we became more aware of their negative effects on people and ecosystems. But now, with fears about how climate change may affect water flows in the future, the goal of creating reservoirs is once more appealing, and dam construction is on the rise."

The new research was made possible by the team's development of a global river map with unprecedented resolution and detail, showing all waterways of the world from small creeks to the largest of rivers, accounting for a cumulative river length of 48.3 million km -- and by a new map of future dam locations assembled by colleagues at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin.

The key components of the team's dam assessment method are two indices that describe river fragmentation and river regulation.

The river fragmentation index (RFI) is a measure of the way that a river's natural flow path (also known as its connectivity) has been disrupted by the creation of dams or by barriers that allow for the transfer of water between basins or towards irrigation areas, for example.
The river regulation index (RRI) is a measure of the proportion of the river water that can be stored in reservoirs, and thus affects the natural fluctuation and properties of river flow downstream.

By combining these two indices, the researchers have arrived at a way of assessing the impact of any existing or planned dam. So, for example, the Danube is severely impacted by fragmentation effects but is relatively weakly affected in terms of flow regulation due to many dams with relatively small reservoirs. The Murray-Darling basin in southern Australia, by contrast, is only weakly affected by fragmentation, but is heavily impacted by flow regulation, due to fewer but larger reservoirs.

"Not all dams are equal," says Gรผnther Grill, a postdoctoral fellow in McGill University's Department of Geography and the lead author on the paper. "Our research assumes that it is not only the size of a dam but also where it is placed along the river that makes a difference. So depending on whether a dam is high up in the mountain headwaters or further down close to the delta, if it is on the main stem of the river or on a small tributary, all of these factors will have varying effects on the rivers and their surrounding ecosystems."

Researchers at the University of Minnesota's Institute on the Environment and the University of Wisconsin's Center for Limnology also contributed to the study.
Some dam and river facts:

There are 6,374 large dams already in existence and 3,377 planned or proposed large dams to be built by 2030.

Currently 48% of the world's river volume is moderately or severely affected by either flow regulation or fragmentation or both.

Assuming that all the dams that are planned or under construction are completed, this number would almost double to 93%, largely due to multiple dams being planned for major tributaries in the Amazon Basin.

Other large rivers that are currently rather free-flowing but on which large dams are planned are the Mekong River in Southeast Asia and the Amur River in Russia.

Scientists twist radio beams to send data: Transmissions reach speeds of 32 gigibits per second

Graphic showing the intensity of the radio beams after twisting.
Credit: Courtesy of Alan Willner / USC Viterbi
Building on previous research that twisted light to send data at unheard-of speeds, scientists at USC have developed a similar technique with radiowaves, reaching high speeds without some of the hassles that can go with optical systems.

The researchers, led by electrical engineering professor Alan Willner of the USC Viterbi School of Engineering, reached data transmission rates of 32 gigabits per second across 2.5 meters of free space in a basement lab at USC.

For reference, 32 gigabits per second is fast enough to transmit more than 10 hour-and-a-half-long HD movies in one second and is 30 times faster than LTE wireless.

"Not only is this a way to transmit multiple spatially collocated radio data streams through a single aperture, it is also one of the fastest data transmission via radio waves that has been demonstrated," Willner said.

Faster data transmission rates have been achieved -- Willner himself led a team two years ago that twisted light beams to transmit data at a blistering 2.56 terabits per second -- but methods to do so rely on light to carry the data.

"The advantage of radio is that it uses wider, more robust beams. Wider beams are better able to cope with obstacles between the transmitter and the receiver, and radio is not as affected by atmospheric turbulence as optics," Willner said.

Willner is the corresponding author of an article about the research that will be published in Nature Communications on Sept. 16. The study's co-lead authors Yan Yan and Guodong Xie are both graduate students at USC Viterbi, and other contributors came from USC, the University of Glasgow, and Tel Aviv University.

To achieve the high transmission rates, the team took a page from Willner's previous work and twisted radio beams together. They passed each beam -- which carried its own independent stream of data -- through a "spiral phase plate" that twisted each radio beam into a unique and orthogonal DNA-like helical shape. A receiver at the other end of the room then untwisted and recovered the different data streams.

"This technology could have very important applications in ultra-high-speed links for the wireless 'backhaul' that connects base stations of next-generation cellular systems," said Andy Molisch of USC Viterbi. Molisch, whose research focuses on wireless systems, co-designed and co-supervised the study with Willner.

Future research will focus on attempting to extend the transmission's range and capabilities.
The work was supported by Intel Labs University Research Office and the DARPA InPho (Information in a Photon) Program.

Source: University of Southern California

Sensors that improve rail transport safety

Cloud-supported sensor network for the condition-based maintenance of rail vehicles.
Credit: © Fraunhofer IZM
A new kind of human-machine communication is to make it possible to detect damage to rail vehicles before it's too late and service trains only when they need it -- all thanks to a cloud-supported, wireless network of sensors.

A train running on damaged wheels could easily be heading for serious trouble. This is why German national rail corporation Deutsche Bahn continuously monitors the wheelsets of its intercity express trains -- a process that costs a considerable amount of time and money. 

Researchers at the Berlin-based Fraunhofer Institute for Reliability and Microintegration IZM are collaborating with industry partners to develop a solution that ensures a great safety while reducing effort and cost. "We want to root out any damage early on and move away from maintenance at set intervals in favor of condition-based maintenance," explains Dr. Michael Niedermayer, microsystems engineer and head of the IZM's Technology-Oriented Design Methods working group. He is also project coordinator for "Mobile Sensor Systems for Condition-Based Maintenance," or MoSe for short.

Seamless monitoring

It's all based on a cloud-supported, wireless network of sensors. Every axle and undercarriage on a train is fitted with small radio sensors, which collect data on the condition of wearing parts. These data are then transferred to the online maintenance cloud, where the measurement and analysis data are encrypted and stored ready for use. The sensors can detect even the tiniest scratch on a ball bearing. As Niedermayer says, "Here we have sensor nodes that can capture even the slightest variations in vibration. We call this in-depth diagnosis." As a result, repairs can be made before anything works its way loose and causes damage.

"What's remarkable about this approach is that it allows everything to be monitored with the train in service, rather than having to inspect it at the rail yard. And in any case, visual checks are not 100 percent reliable," says Manfred Deutzer from project partner Deutzer Technische Kohle GmbH. Although there are wired sensors out there that can be used to examine rail vehicle chassis for wear and tear, these fail to match the high diagnostic quality standards the MoSe developers are striving for.

Using the new method, it is possible to get precise data on, say, whether an axle bearing will have to be replaced three months down the line, which avoids the need to replace it prematurely just in case. The latter is just as uneconomical as the custom of overhauling wheels at preset intervals with a view to resolving any wheel flats that could damage rails. 

"Wheels can tolerate such repairs no more than three times before they have to be scrapped," Deutzer reports. "It would make more sense and cost less to grind only those wheels we know actually turn poorly. The problem is that there has never been a suitable way of checking for wheel flats." MoSe is to change all that and much more besides.

"Not only do we intend to improve diagnostics, a top priority is also to process the data collected in as detailed and tailored a manner as possible," says Niedermayer. The idea is to provide train drivers with all relevant data (for instance about critical wheel damage), diagnostic technicians with detailed measurement data so they can assess how fast gear damage is progressing, and designers with measurement statistics covering wear to all parts, enabling them to improve the technical design of the next product generation. Making sure everyone involved receives the data they need in a form they can work with right away involves developing some clever diagnostic algorithms. "Yet another advantage is that wireless sensors can be easily retrofitted," adds Niedermayer.

What's also new is that the system can adapt to the different rotational speeds of the parts being examined -- such as the wheels on a train -- and in doing so, deliver incredibly precise data at whatever speed the train happens to be traveling. It used to be that sensors were designed to work at constant rotational speeds. Although this setup may be easier to manage, it means that the diagnostic quality suffers. Thanks to analysis algorithms, this is set to change. But developing these algorithms is a balancing act: "Since the system is intended to work without batteries, the algorithms mustn't drain unnecessary energy by using up excessive computing power," explains Niedermayer. As MoSe uses energy harvesting, it can tap energy from the vibrations and heat generated as the parts rotate.

Over the next couple of years a prototype will be developed that will be tested in a tram run by the German city of Brandenburg an der Havel. The system could then be used for monitoring purposes in suburban or long-distance trains.

Source: Fraunhofer-Gesellschaft

Cheaper 3-D virtual reality system: Powerful enough for a gamer, made for an engineer

Written By Unknown on Tuesday, January 6, 2015 | 3:00 AM

It's like a scene from a gamer's wildest dreams: 12 high-definition, 55-inch 3D televisions all connected to a computer capable of supporting high-end, graphics-intensive gaming.
Credit: Image courtesy of Brigham Young University
It's like a scene from a gamer's wildest dreams: 12 high-definition, 55-inch 3D televisions all connected to a computer capable of supporting high-end, graphics-intensive gaming.

On the massive screen, images are controlled by a Wii remote that interacts with a Kinnect-like Bluetooth device (called SmartTrack), while 3D glasses worn by the user create dizzying added dimensions.

But this real-life, computer-powered mega TV is not for gaming. It's for engineering.
Welcome to Brigham Young University's VuePod, a 3D immersive visualization environment run by BYU's Department of Civil and Environmental Engineering. Student-built and operated, under the supervision of civil engineering professor Dan Ames, the VuePod is changing the way engineers are viewing environmental engineering challenges.

"This is gold," said fellow BYU civil engineering professor Kevin Franke. "This technology has the ability to revolutionize my job as an earthquake engineer."

That's because the VuePod allows users to virtually fly over, wander through or hover above 3D environments that are otherwise difficult to visit. The images are created by point data from aircraft equipped with LIDAR (think RADAR, but with lasers). The LIDAR scans the landscape and records millions of data points that are then viewed as an image on the VuePod. Point data can also be created from stitched-together photographs taken from low-cost drones, which is Franke's research focus.

One set of data currently available for study in the VuePod captured a canyon area beneath a plateau in southern Idaho. With 3D glasses and the Wii controller, a user can virtually drop down into the canyon from above, and then fly from one end to the other.

As cool as it is to fly through a canyon, the real engineering application comes in when you combine two sets of data for the same canyon, taken five years a part. With the second set of data, changes in the natural landscape that are invisible to the human eye become clear as day. Thanks to the VuePod's massive 108-square-foot screen, all of the image-making data can be presented for viewing.

"Our eyes and our brains are so amazing; we need to take full advantage of them," Ames said. "That's the value of this project: we're presenting more information for the human eyes to detect changes."

In addition to natural change detection, the VuePod has the potential to assist in infrastructure monitoring -- such as tracking how highways hold up (or slough and crack) over time and seeing the affect on buildings after severe weather or earthquakes.
While the VuePod is certainly not the first immersive visualization system in academia, it may just be the most cost efficient built to date. Some systems cost as much as $10 million to build and maintain, while BYU's VuePod just barely topped the $30,000 mark.
Ames details how BYU was able to build such a powerful system for so little in a new paper published by the Journal of Computing in Civil Engineering.

"Our question has been: How can we make this technology accessible?" Ames said. "We're trying to determine the threshold for getting the most function at the most affordable cost. Ultimately, the goal is to take an expensive tool and make it cheaper for an everyday engineering firm to use."

And even though Ames and his students have achieved that, they believe much more can be done.

"We want whoever reads this paper to be able to build a better system than we built," he said.

Heavy metals and hydroelectricity

Written By Unknown on Monday, December 8, 2014 | 9:30 PM

August 2014 GSA Today cover image: The northeastern shoreline of Lake Junรญn, Peru. The pristine water surface belies a high level of heavy metal contamination of surface sediments. Credit: Donald T. Rodbell
Hydraulic engineering is increasingly relied on for hydroelectricity generation. However, redirecting stream flow can yield unintended consequences. In the August 2014 issue of GSA Today, Donald Rodbell of Union College-Schenectady and coauthors from the U.S. and Peru document the wholesale contamination of the Lake Junรญn National Reserve by acid mine drainage from the Cerro de Pasco mining district.

According to the World Bank, about 60% of Peru's electricity is generated by hydropower, which during the dry season relies heavily on glacial meltwater to augment stream flow. The ongoing reduction in ice cover in Peru that began early in the twentieth century has reduced the aerial extent of glacial ice in some areas by nearly 30%. According to this GSA Today article, climate models project that warming will be pronounced in the highest elevation regions of the tropical Andes, and thus acceleration in ice loss is likely.

To maintain dry-season river discharge and energy generation for a growing Peruvian population, the hydropower industry in Peru has turned to hydraulic engineering, including dam construction. This study highlights an unintended consequence of early dam construction in the Cerro de Pasco region of the central Peruvian Andes, a region that has been a focal point of Peruvian mining operations for centuries.

The Cerro de Pasco mining district is among the most extensively worked mining districts in Peru. Pre-colonial mining there showed some of the earliest evidence of anthropogenic lead enrichment by aerosolic fallout in nearby lakes about 600 years ago. The first copper smelter was established there in 1906, and in 1931 the new and improved Cerro smelter held monopoly over the refining of all nonferrous metals in Peru.

In order to generate hydroelectricity for Cerro de Pasco's operations, the Upamayo Dam was constructed in 1932. The Upamayo Dam is located in the uppermost reach of the Rรญo Mantaro, immediately downstream of the confluence between the Rรญo San Juan, which drains southward from Cerro de Pasco, and the outflow of Lake Junรญn, the largest lake entirely within Peru.

The location of the Upamayo Dam and the small reservoir upstream from it has resulted in the discharge of Rรญo San Juan waters, once destined for the Rรญo Mantaro, directly into Lake Junรญn. Rodbell et al.'s GSA Today paper documents the impact of acid mine drainage from Cerro de Pasco into Lake Junรญn, which in 1974 was designated a Peruvian National Wildlife Reserve.

As a result of the drainage, the upper several decimeters of sediment in the lake now contain levels of lead and zinc that greatly exceed the U.S. Environmental Protection Agency limits for the lake basin. Today, more than 60,000 metric tons of copper, almost 900,000 metric tons of zinc, and almost 41,000 metric tons of lead are contained in the upper 50 cm of lake sediment -- the zinc tonnage representing more than five years' worth of mining production at current rates.

Rodbell and colleagues write that among the biggest challenges that will face any attempt to mitigate the environmental disaster that has befallen Lake Junรญn are finding ways to stop the recycling of zinc from the lake bottom and the remobilization of all metals from the seasonally exposed and submerged deposits that are trapped behind the Upamayo Dam. Finally, they note that as future hydraulic engineering projects are developed in Peru and elsewhere, it would behoove all not to repeat the mistakes that are recorded in the mud of Lake Junรญn.

Source: Geological Society of America

The 70-foot-long, 52-ton concrete bridge survives series of simulated earthquakes

Written By Unknown on Wednesday, October 29, 2014 | 10:22 PM

A new, rocking, pre-tensioned concrete bridge support system has been developed by the University of Washington that reduces on-site construction time and minimizes earthquake damage. The 52-ton, 70-foot-long concrete bridge, built atop three 14- by 14-foot, 50-ton-capacity hydraulically driven shake tables at the University of Nevada, Reno, was shaken in a series of simulated earthquakes, culminating in the large ground motions recorded in the deadly and damaging 1995 magnitude 6.9 earthquake in Kobe, Japan.
A 70-foot-long, 52-ton concrete bridge survived a series of earthquakes in the first multiple-shake-table experiment in the University of Nevada, Reno's new Earthquake Engineering Lab.

"It was a complete success. The bridge withstood the design standard very well and today went over and above 2.2 times the design standard," John Stanton, civil and environmental engineering professor and researcher from the University of Washington, said. Stanton collaborated with Foundation Professor David Sanders of the University of Nevada, Reno in the novel experiment.

"The bridge performed very well," Sanders said. "There was a lot of movement, about 12 percent deflection -- which is tremendous -- and it's still standing. You could hear the rebar inside the columns shearing, like a zipper opening. Just as it would be expected to do."

The set of three columns swayed precariously, the bridge deck twisted and the sound filled the cavernous laboratory as the three 14- by 14-foot, 50-ton-capacity hydraulically driven shake tables moved the massive structure.

"Sure we broke it, but we exposed it to extreme, off-the-scale conditions," Stanton said. "The important thing is it's still standing, with the columns coming to rest right where they started, meaning it could save lives and property. I'm quite happy."

The bridge was designed and the components were pre-cast at the University of Washington in Seattle, and then built atop three 14- by 14-foot, 50-ton-capacity hydraulically driven shake tables in the 24,500 square-foot lab. It was shaken in a series of simulated earthquakes, culminating in the large ground motions similar to those recorded in the deadly and damaging 1995 magnitude 6.9 earthquake in Kobe, Japan.

The rocking, pre-tensioned concrete bridge support system is a new bridge engineering design the team has developed with the aim of saving lives, reducing on-site construction time and minimizing earthquake damage.

"By building the components off-site we can save time with construction on-site, minimizing interruptions in traffic and lowering construction costs," Sanders said. "In this case, the concrete columns and beams were pre-cast and tensioned at the University of Washington. Other components were built here at the University of Nevada, Reno. It took us only a month to build the bridge, in what would otherwise be a lengthy process."

"This can't be done anywhere else in the nation, and perhaps the world," Ian Buckle, director of the lab and professor of civil engineering, said of the test. "Of course we've been doing these types of large-scale structures experiments for years, but it's exciting to have this first test using multiple tables in this building complete. It's good to see the equipment up and running successfully.

When combined with the University's Large-Scale Structures Laboratory, just steps away from the new lab, the facility comprises the biggest, most versatile large-scale structures, earthquake/seismic engineering facility in the United States, according to National Institute of Standards and Technology, and possibly the largest University-based facility of its kind in the world.

A grand opening was held recently for the $19 million lab expansion project, funded with $12.2 million by the U.S. Department of Commerce's National Institute of Standards and Technology, funds from the Department of Energy, as well as University and donor funds. The expansion allows a broader range of experiments and there is additional space to add a fifth large shake table.

"Our facility is unique worldwide and, combined with the excellence of our faculty and students, will allow us to make even greater contributions to the seismic safety of our state, the nation and the world," Manos Maragakis, dean of the College of Engineering, said. "We will test new designs and materials that will improve our homes, hospitals, offices and highway systems. Remarkable research is carried on here. Getting to this point has taken a lot of hard work. It's both a culmination and a beginning, ushering in a new era."

Source: University of Nevada, Reno

New bridge design improves earthquake resistance, reduces damage and speeds construction

This graphic illustrates a new design for the framework of columns and beams that support bridges, called "bents," to improve performance for better resistance to earthquakes, less damage and faster on-site construction. The faster construction is achieved by prefabricating the columns and beams off site and later erecting and connecting them quickly at the construction site. Credit: University of Washington, Seattle/NEES photo
Researchers have developed a new design for the framework of columns and beams that support bridges, called "bents," to improve performance for better resistance to earthquakes, less damage and faster on-site construction.

The faster construction is achieved by pre-fabricating the columns and beams off-site and shipping them to the site, where they are erected and connected quickly.

"The design of reinforced concrete bridges in seismic regions has changed little since the mid-1970s," said John Stanton, a professor in the Department of Civil and Environmental Engineering at the University of Washington, Seattle, who developed the concept underlying the new design. The team members include professor Marc Eberhard and graduate research assistants Travis Thonstad and Olafur Haraldsson from the University of Washington; and professor David Sanders and graduate research assistant Islam Mantawy from the University of Nevada, Reno.

Research findings are included in a paper being presented during Quake Summit 2014, the annual meeting for the National Science Foundation's George E. Brown, Jr. Network for Earthquake Engineering Simulation, a shared network of laboratories based at Purdue University. This year's summit is part of the 10th U.S. National Conference on Earthquake Engineering on July 21-25 in Anchorage, Alaska.

Until now the majority of bridge bents have been made using concrete that is cast in place, but that approach means time is needed for the concrete to gain strength before the next piece can be added. Pre-fabricating the pieces ahead of time eliminates this requirement, speeding on-site construction and reducing traffic delays.

"However, pre-fabricating means the pieces need to be connected on-site, and therein lies a major difficulty," Stanton said. "It is hard enough to design connections that can survive earthquake shaking, or to design them so that they can be easily assembled, but to do both at once is a real challenge."
Moreover, the researchers have achieved this goal using only common construction materials, which should smooth the way for owners and contractors to accept the new approach, he said.

An important feature of the new system is that the columns are pre-tensioned.

"A good analogy is to think of a series of a child's wooden building blocks, each with a hole through it," Stanton said. "Stack them on top of one another, put a rubber band through the central hole, stretch it tight and anchor it at each end. The rubber band keeps the blocks squeezed together. Now stand the assembly of blocks up on its end and you have a pre-tensioned column. If the bottom of the column is attached to a foundation block, you can push the top sideways, as would an earthquake, but the rubber band just snaps the column back upright when you let go."

This "re-centering" action is important because it ensures that, directly after an earthquake, the bridge columns are vertical and not leaning over at an angle. This means that the bridge can be used by emergency vehicles in the critical moments immediately following the earthquake.

"Of course, the real bridge columns do not contain rubber bands, but very high-strength steel cables are used to achieve the same behavior," Stanton said.

To keep the site operations as simple as possible, those cables are stressed and embedded in the concrete at the plant where the columns are fabricated. The columns also contain some conventional rebar, which is also installed in the fabrication plant.

The technology was pioneered in the building industry in the 1990s but is now being adapted for use with bridges.

When the columns rock during an earthquake, they experience high local stresses at the points of contact, and without special measures the concrete there would crush. To counteract this possibility, the researchers protected the ends of the columns with short steel tubes, or "jackets," that confine the concrete, not unlike the hoops of a barrel, or the steel cap that ranchers use to protect the top of a fence-post while driving it into the ground.

"Cyclic tests of the critical connections have demonstrated that the system can deform during strong earthquakes and then bounce back to vertical with minimal damage," Stanton said.

Those tests were conducted on individual connections by graduate assistants Olafur Haraldsson, Jeffrey Schaefer and Bryan Kennedy. In July, the team will test a complete bridge built with the system. The test will be conducted at 25 percent of full-scale on the earthquake-shaking tables at a facility at the University of Nevada, Reno. The facility is part of NEES.

Travis Thonstad led the design and built the components for that test. The column and cap beam components were then shipped to the University of Nevada, Reno, where Islam Mantawy is leading the construction of the bridge. The team from Washington and Nevada will be processing the data from this project, and it will be archived and made available to the public through NEES.

The Quake Summit paper was authored jointly by the team. The research was supported by the NSF, the Pacific Earthquake Engineering Research (PEER) Center and the Valle Foundation of the University of Washington.

Source: Purdue University

The Floating nuclear plants could ride out tsunamis: New design for enhanced safety, easier siting and centralized construction

This illustration shows a possible configuration of a floating offshore nuclear plant, based on design work by Jacopo Buongiorno and others at MIT's Department of Nuclear Science and Engineering. Like offshore oil drilling platforms, the structure would include living quarters and a helipad for transportation to the site.
Credit: Illustration courtesy of Jake Jurewicz/MIT-NSE
When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects -- specifically, the lack of cooling for the reactor cores, due to a shutdown of all power at the station -- that caused most of the harm.

A new design for nuclear plants built on floating platforms, modeled after those used for offshore oil drilling, could help avoid such consequences in the future. Such floating plants would be designed to be automatically cooled by the surrounding seawater in a worst-case scenario, which would indefinitely prevent any melting of fuel rods, or escape of radioactive material.

The concept is being presented this week at the Small Modular Reactors Symposium, hosted by the American Society of Mechanical Engineers, by MIT professors Jacopo Buongiorno, Michael Golay, and Neil Todreas, along with others from MIT, the University of Wisconsin, and Chicago Bridge and Iron, a major nuclear plant and offshore platform construction company.

Such plants, Buongiorno explains, could be built in a shipyard, then towed to their destinations five to seven miles offshore, where they would be moored to the seafloor and connected to land by an underwater electric transmission line. The concept takes advantage of two mature technologies: light-water nuclear reactors and offshore oil and gas drilling platforms. Using established designs minimizes technological risks, says Buongiorno, an associate professor of nuclear science and engineering (NSE) at MIT.

Although the concept of a floating nuclear plant is not unique -- Russia is in the process of building one now, on a barge moored at the shore -- none have been located far enough offshore to be able to ride out a tsunami, Buongiorno says. For this new design, he says, "the biggest selling point is the enhanced safety."

A floating platform several miles offshore, moored in about 100 meters of water, would be unaffected by the motions of a tsunami; earthquakes would have no direct effect at all. Meanwhile, the biggest issue that faces most nuclear plants under emergency conditions -- overheating and potential meltdown, as happened at Fukushima, Chernobyl, and Three Mile Island -- would be virtually impossible at sea, Buongiorno says: "It's very close to the ocean, which is essentially an infinite heat sink, so it's possible to do cooling passively, with no intervention. The reactor containment itself is essentially underwater."
Buongiorno lists several other advantages. For one thing, it is increasingly difficult and expensive to find suitable sites for new nuclear plants: They usually need to be next to an ocean, lake, or river to provide cooling water, but shorefront properties are highly desirable. By contrast, sites offshore, but out of sight of land, could be located adjacent to the population centers they would serve. "The ocean is inexpensive real estate," Buongiorno says.

In addition, at the end of a plant's lifetime, "decommissioning" could be accomplished by simply towing it away to a central facility, as is done now for the Navy's carrier and submarine reactors. That would rapidly restore the site to pristine conditions.

This design could also help to address practical construction issues that have tended to make new nuclear plants uneconomical: Shipyard construction allows for better standardization, and the all-steel design eliminates the use of concrete, which Buongiorno says is often responsible for construction delays and cost overruns.

There are no particular limits to the size of such plants, he says: They could be anywhere from small, 50-megawatt plants to 1,000-megawatt plants matching today's largest facilities. "It's a flexible concept," Buongiorno says.

Most operations would be similar to those of onshore plants, and the plant would be designed to meet all regulatory security requirements for terrestrial plants. "Project work has confirmed the feasibility of achieving this goal, including satisfaction of the extra concern of protection against underwater attack," says Todreas, the KEPCO Professor of Nuclear Science and Engineering and Mechanical Engineering.
Buongiorno sees a market for such plants in Asia, which has a combination of high tsunami risks and a rapidly growing need for new power sources. "It would make a lot of sense for Japan," he says, as well as places such as Indonesia, Chile, and Africa.

Source: Massachusetts Institute of Technology

The Ground-improvement methods might protect against earthquakes

Researchers are using T-Rex, a 64,000-pound shaker truck, in research to increase the resilience of homes and low-rise structures built on top of soils prone to liquefaction during strong earthquakes. T-Rex is based at a University of Texas at Austin facility that is part of the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), a distributed laboratory with 14 sites around the United States. Credit: NEES photo

Researchers from the University of Texas at Austin's Cockrell School of Engineering are developing ground-improvement methods to help increase the resilience of homes and low-rise structures built on top of soils prone to liquefaction during strong earthquakes.

Findings will help improve the safety of structures in Christchurch and the Canterbury region in New Zealand, which were devastated in 2010 and 2011 by a series of powerful earthquakes. Parts of Christchurch were severely affected by liquefaction, in which water-saturated soil temporarily becomes liquid-like and often flows to the surface creating sand boils.

"The 2010-2011 Canterbury earthquakes in New Zealand have caused significant damage to many residential houses due to varying degrees of soil liquefaction over a wide extent of urban areas unseen in past destructive earthquakes," said Kenneth Stokoe, a professor in the Department of Civil, Architectural and Environmental Engineering. "One critical problem facing the rebuilding effort is that the land remains at risk of liquefaction in future earthquakes. Therefore, effective engineering solutions must be developed to increase the resilience of homes and low-rise structures."
Researchers have conducted a series of field trials to test shallow-ground-improvement methods.
"The purpose of the field trials was to determine if and which improvement methods achieve the objectives of inhibiting liquefaction triggering in the improved ground and are cost-effective measures," said Stokoe, working with Brady Cox, an assistant professor of civil engineering. "This knowledge is needed to develop foundation design solutions."

Findings were detailed in a research paper presented in December at the New Zealand -- Japan Workshop on Soil Liquefaction during Recent large-Scale Earthquakes. The paper was authored by Stokoe, graduate students Julia Roberts and Sungmoon Hwang; Cox and operations manager Farn-Yuh Menq from the University of Texas at Austin; and Sjoerd Van Ballegooy from Tonkin & Taylor Ltd, an international environmental and engineering consulting firm in Auckland, New Zealand.

The researchers collected data from test sections of improved and unimproved soils that were subjected to earthquake stresses using a large mobile shaker, called T-Rex, and with explosive charges planted underground. The test sections were equipped with sensors to monitor key factors including ground motion and water pressure generated in soil pores during the induced shaking, providing preliminary data to determine the most effective ground-improvement method.

Four ground-improvement methods were initially selected for the testing: rapid impact compaction (RIC); rammed aggregate piers (RAP), which consist of gravel columns; low-mobility grouting (LMG); and construction of a single row of horizontal beams (SRB) or a double row of horizontal beams (DRB) beneath existing residential structures via soil-cement mixing.

"The results are being analyzed, but good and poor performance can already be differentiated," Stokoe said. "The ground-improvement methods that inhibited liquefaction triggering the most were RIC, RAP, and DRB. However, additional analyses are still underway."

The test site is located along the Avon River in the Christchurch suburb of Bexley. The work is part of a larger testing program that began in early 2013 with a preliminary evaluation by Brady Cox of seven potential test sites along the Avon River in the Christchurch area.

Funding for the research has been provided, in part, by the National Science Foundation and is affiliated with the NSF's George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES). The remainder of the funding has been provided by the Earthquake Commission of the New Zealand Government.

The 64,000-pound T-Rex, operated by NEES@UTexas at UT Austin, is used to simulate a wide range of earthquake shaking levels.

NEES is a shared network of 14 experimental facilities, collaborative tools, centralized data repository and earthquake simulation software, all linked by high-speed Internet connections.

Source: Purdue University
 
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