Virginia Tech researcher explores using SERS for detecting environmental pollutants

Rapid pollutant detection can prevent widespread outbreaks. While many techniques exist for detecting such contamination, they generally require highly specific instruments for each contaminant. Peter Vikesland, professor of civil and environmental engineering at Virginia Tech, and Haoran Wei of Zaozhuang in Shandong, China, a doctoral student in environmental engineering, describe challenges related to deploying surface-enhanced Raman spectroscopy (SERS) for detection in their paper published by Scientific Reports, “pH-Triggered Molecular Alignment for Reproducible SERS Detection via an AuNP/Nanocellulose Platform.”

SERS has great potential for ultrasensitive chemical analysis and detection of multiple contaminants in a range of environments. Capable of detecting single molecules without excessively expensive equipment or sample pretreatment, SERS has promised rapid field and point-of-use detection that could prevent pollution or biohazard threats and stop outbreaks before they begin. But that promise has gone largely unfulfilled.

One problem is that many of the substances that SERS could potentially detect are moderately hydrophobic, or water-repellent, thus making it harder to attract them to the hydrophilic, or water-loving, gold or silver nanoparticle surfaces used for SERS. Efforts to use molecular traps to better bind target molecules have been explored, but they have added complexity to the material synthesis and tend to produce background signals that complicate data analysis.

In the paper, Vikesland describes a study he and Wei conducted using bacterial cellulose as a SERS platform created by synthesizing nanocomposites made of bacterial cellulose interlaced with gold nanoparticles. Bacterial cellulose makes an excellent base for a SERS substrate. It is low-cost and easily fabricated, and its fibers are nanoscale in diameter and retain their 3-D structure in water.

The study used this platform to attempt to detect a number of common pollutants — carbamazepine, atrazine, and melamine, among others. By manipulating the suspension pH, the authors were able to consistently and reproducibly increase the SERS signal due to the increased affinity for the pollutant to the substrate at low pH.

A SERS platform based on bacterial cellulose could finally help fulfill the promise of this exciting technology. The platform can be synthesized in a one-step process and it can be reused many times. The protocol could simplify and reduce the cost of detecting many compounds. The platform is easy and cheap to synthesize and provides short sampling and detection times.

Vikesland also leads an international team of researchers as the principal investigator for a five-year $3.6 million Partnerships in International Research and Education grant from the National Science Foundation. They seek to halt wastewater-derived antimicrobial resistance dissemination.

ACEC California announces Engineering Excellence Awards that showcase unique projects

The American Council of Engineering Companies, California (ACEC California) recently unveiled the 2016 recipients of its Engineering Excellence Awards, highlighting some uniques projects in the state. In all, 24 California firms representing 27 projects were named, the majority of which were public works projects completed in partnership with local government entities throughout the state. Because of their selection by ACEC California, Honor Award winners are eligible to enter the ACEC national level Engineering Excellence Awards competition. 

"Each year, the recipients of the ACEC California Engineering Excellence Awards represent some of the most innovative solutions to complex public and private sector challenges, including traffic congestion, water resource management, alternative fuel infrastructure, and structural building projects, to name a few," says Brad Diede, executive director for ACEC California. "Engineering continues to help California thrive, and I am deeply proud of our industry accomplishments that directly improve Californians' lives."

 

ACEC California's annual Engineering Excellence Awards entries are accepted into one of 12 project categories: studies; research and consulting engineering services; building/technology systems; structural systems; surveying and mapping technology; environmental; waste and storm water; water resources; transportation; special projects; small projects; energy; and industrial and manufacturing processes and facilities. An independent panel of judges from the public sector evaluated the projects and made the award selections.

 

Honor Awards were granted to 14 firms, including Cornerstone Structural Engineering Group of San Francisco for its work on the San Francisco Zoo-South American Rain Forest Exhibit in San Francisco and the R.B. Oliver Bridge Replacement in Tulare County. Cornerstone was contracted by Tulare County in 2010 as the prime consultant to design the state-of-the-art bridge replacement project. Because of the design team's knowledge of the Kings River and partnering between the design team and the County of Tulare, the final design of the project was delivered in less than 2 years, an unprecedented pace for a $20 million bridge replacement project. The project also included development of new bat habitats, which have increased the bat population at the bridge to four times its original number.

Cornerstone provided the structural engineering services required to create the San Francisco Zoo's South American Rain Forest Exhibit, its newest exhibit, as well as seismically retrofit the historic WPA building. The Aviary features a realistic rainforest ecosystem, full of colorful free-flight birds, exotic plants and trees, a two-toed sloth, and the Zoo's first significant herpetological collection, which will include a 15-foot long green anaconda as well as rare tree frogs, turtles, lizards, and snakes.

Mark Thomas and Company of San Jose received an Honor Award for its work on the I-280/ I-880/ Stevens Creek Boulevard Interchange Project in San Jose. The I-280/I-880/Stevens Creek Boulevard Interchange Project, delivered for the Santa Clara Valley Transportation Authority (VTA), improved this highly congested facility. The existing interchange was a full cloverleaf configuration originally constructed in 1959. Since that time, the cities of San Jose and Santa Clara have grown tremendously, and the facility had become outdated. Additionally, the interchange is adjacent to the busiest shopping area in Santa Clara County, including Valley Fair and Santana Row. The reconfiguration allowed for increased traffic capacity, enhanced bicycle and pedestrian facilities, and  accommodated the Stevens Creek Boulevard Bus Rapid Transit (BRT) alignment. Lastly, the project design incorporated aesthetic treatments and sustainable stormwater handling facilities.

McMillen Jacobs Associates of Walnut Creek was honored for its work on the Bay Tunnel in Menlo Park/ Newark, the first tunnel excavated under the San Francisco Bay. The $288 million project is a successful and significant part of San Francisco Public Utilities Commission's (SFPUC) $4.6 billion Water System Improvement Program to upgrade the Hetch Hetchy Water System, which brings water through gravity-fed pipes from Yosemite National Park to the San Francisco Bay Area. The Bay Tunnel extends 5 miles under the Bay, replacing the aging water pipeline infrastructure built in the 1920s and 1930s that presently traverses the Bay on wooden trestles. The tunnel provides up to 224 million gallons per day of high-quality drinking water to about 2.6 million of SFPUC's customers in the Bay Area.

Walter P Moore of San Francisco, received an award for its work on the Air Traffic Control Tower and Intergraded Facilities Building at San Francisco International Airport. The iconic new tower, which replaced SFO's long outdated 1960s-era control tower, is the first air traffic control tower delivered through a partnership between the airport and the FAA. The tower relies on an innovative vertical post-tensioned system to self-right the structure during a major seismic event, ensuring that air traffic controllers remain fully operational after a magnitude 7.5 earthquake. This is crucial since the airport is just four miles from the San Andreas Fault.

Stover Engineering of Crescent City and COWI (formerly Ben C. Gerwick, Inc.) of Oakland were cited for their work on the Crescent City Harbor Inner Boat Basin Reconstruction Project  in Crescent City. This $32.7 million tsunami-damage repair project is the first known marina in North America designed to withstand a significant tsunami event. Marinas currently have no established design criteria for tsunamis, so the project required engineering judgment to justify the repairs to both funding and permitting agencies. Modeling performed to establish the tsunami loads was validated by a subsequent tsunami that occurred prior to final design of the project.

GHT principal Ray Smith elected to Building Commissioning Certification Board Examination Committee

GHT Limited (GHT), a DC metro area mechanical, electrical, and plumbing (MEP) consulting engineering firm, announces that principal Ray Smith has been elected to the Examination Committee of the Building Commissioning Certification Board (BCCB). The Examination Committee consists of national subject matter experts who collaborate and employ best practices to create the Certified Commissioning Professional (CCP) examination forms. The committee’s responsibilities include writing, reviewing, and approving questions; creating and approving the form; and setting the passing score for a minimally competent practitioner.

The BCCB was formed in 2004 as an administratively independent arm of the Building Commissioning Association (BCA) for the purpose of recognizing building commissioning professionals who meet the standards of the BCA. Its mission is to provide commissioning professionals with the premier industry-recognized commissioning certification program that accurately validates their professional skill level, is accepted as the standard within the industry, and is recognized within the building community and governmental agencies.

Ray Smith specializes in optimizing the performance of MEP systems in new and existing buildings. As Section Head of Commissioning and Building Operations Consulting in GHT's Operations and Energy Services (OES) studio, he works closely with facility owners, managers, and operators to solve problems, develop strategies for operational excellence, and provide commissioning services that focus on long-term performance goals. He has more than 40 years of experience in the built environment, including three years of building operations experience. His unique combination of design and field experience and MEP system performance expertise makes him a resource for MEP studies, troubleshooting, forensic evaluations, concept option studies, payback analyses, post-installation training, and all levels of commissioning.

GHT provides mechanical, electrical, and plumbing (MEP) engineering solutions for the built environment. Their approach integrates proven techniques with the latest technologies and sustainable design practices. In addition to MEP design and commissioning for base building systems and interiors, GHT offers operations and energy services that enhance building performance and real estate advisory services that inform investment decisions. For 50 years, GHT has strived to improve efficiency and value for commercial, institutional, and government real estate in the Washington, DC region.

Sanborn Head celebrates new Boston Bruins training facility

Stan Sadkowski and Amy Blomeke of Sanborn, Head & Associates were part of the recent Topping Off ceremony for the new Boston Bruins’ Training Facility at Warrior Ice Arena.  As part of the Boston Landing Development, Sanborn Head is working with NB Development Group to provide geotechnical engineering, environmental engineering, LSP services, and construction administration services for the majority of the Boston Landing development, including the new practice rink for the Bruins.

As Mayor Walsh mentioned at the ceremony, “This is more than a hockey rink. Boston Landing is an economic engine for Brighton, Allston and the entire City. This development is a great way to introduce people to the city of Boston.” The other projects on this site include the New Balance Corporate World Headquarters, a state-of-the-art indoor sports complex (including track), and a new MBTA Commuter Rail Station.   

Sanborn Head was one member of a larger design and construction team that includes the HYM Investment Group, Elkus Manfredi Architects, John Moriarty & Associates (JMA), Beals Associates, McNamara/Salvia, WSP, and the NB Development Group.

Sanborn Head provides geotechnical engineering and environmental consulting services to real estate development, industrial, solid waste, energy, and public sector clients.  More information can be found at www.sanbornhead.com.  

Duke engineers help Siri hear through a cocktail party

People trying to talk to Siri, the operating system used on various Apple devices, may soon no longer have to look like they’re about to eat their iPhones, thanks to a new technology demonstration that solves the problem of crowd noise. In a crowded room with voices coming from every direction, the human auditory system is incredibly good at homing in on a single voice while filtering out the background jabber, but computers are not.

A new approach from engineers at Duke University, however, may soon improve their performance in loud environments. They have developed a sensor that uses metamaterials -- the combination of natural materials in repeating patterns to achieve unnatural properties -- and compressive sensing to determine the direction of a sound and extract it from the surrounding background noise. Once miniaturized, the device could have applications in voice-command electronics, medical sensing devices that use waves, like ultrasound, and hearing aids and cochlear implants. Their study appeared in the Proceedings of the National Academy of Sciences.

“We’ve invented a sensing system that can efficiently, reliably, and inexpensively solve an interesting problem that modern technology has to deal with on a daily basis,” says Abel Xie, a PhD student in electrical and computer engineering at Duke and lead author of the paper. “We think this could improve the performance of voice-activated devices like smart phones and game consoles while also reducing the complexity of the system.”

The proof-of-concept device looks a bit like a thick, plastic, pie-shaped honeycomb split into dozens of slices. While the honeycomb’s openings may all look the same, their depth varies from hole to hole. This gives each slice of the honeycomb pie a unique pattern.

“The cavities behave like soda bottles when you blow across their tops,” says Steve Cummer, professor of electrical and computer engineering at Duke. “The amount of soda left in the bottle, or the depth of the cavities in our case, affects the pitch of the sound they make, and this changes the incoming sound in a subtle but detectable way.”

When a sound wave gets to the device, it becomes slightly distorted by these cavities. And that distortion has a specific signature depending what slice of the pie it passed over. After being picked up by a microphone on the other side, the sound is transmitted to a computer that can separate the jumble of noises based on these unique distortions. The researchers tested their invention in multiple trials by simultaneously sending three identical sounds at the sensor from three different directions. It was able to distinguish between them with a 96.7 percent accuracy rate.

While the prototype is six inches wide, the researchers believe it could be scaled down and incorporated into the devices we use on a regular basis. And because the sensor is made of plastic and does not have any electric or moving parts, it is extremely efficient and reliable.

“This concept may also have applications outside the world of consumer electronics,” Xie reports. “I think it could be combined with any medical imaging device that uses waves, such as ultrasound, to not only improve current sensing methods but to create entirely new ones.

With the extra information, it should also be possible to improve the sound fidelity and increase functionalities for applications like hearing aids and cochlear implants. One obvious challenge is to make the system physically small. It is challenging, but not impossible, and we are working toward that goal.”

This work was supported by a Multidisciplinary University Research Initiative under a grant from the Office of Naval Research.

GAI wins Pennsylvania Turnpike construction inspection services contract

GAI Consultants has been selected to provide construction services on an open-end contract basis for several construction packages on the Pennsylvania Turnpike’s Southern Beltway between SR 0022 and I-79 in Allegheny and Washington Counties. Projects to be inspected under this agreement will include roadway, bridge, and interchange construction

·          GAI will serve as a subconsultant to L.R. Kimball and will provide inspection support for the construction management team already in place. Each agreement will be for a maximum cost of $6.5 million or for a 48-month period, whichever comes first, with inspection services assigned on an as-needed basis. Possible assignments include inspection for the following design sections:

o   Section 55W, wetland/streams/terrestrial mitigation

o   Section 55-A-1, Exit 6 and Exit 9 interchanges

o   Section 55-A2, Exit 11 interchange

o   Section 55-B, mainline side road improvements

o   Section 55-C1, Exit 16 interchange

o   Section 55-C2-1, I-79 widening

o   Section 55-C2, Exit 18 interchange

o   Section 55-S

In business since 1958, GAI is an employee-owned planning, engineering, and environmental consulting firm providing local expertise to worldwide clients in the energy, transportation, development, government, and industrial markets. The firm has offices throughout the southeastern and midwestern United States. For more information, visit www.gaiconsultants.com.

Parsons Brinckerhoff expands staff in San Diego office

WSP | Parsons Brinckerhoff, a global engineering and professional services organization, has added three professionals to the staff of its San Diego, CA office. Joining the firm are Miguel Galvan, senior supervising engineer, Richard Bottcher, senior engineering manager, and Darryl Carty, senior architectural manager.

Galvan will be responsible for designing stormwater management systems along major highways and rail corridors in Southern California. He has nearly 20 years of experience in urban grading, urban drainage system planning and design, stormwater pollution prevention, and erosion control design. Prior to joining WSP | Parsons Brinckerhoff, he was a senior supervising engineer for a California engineering firm, providing stormwater engineering services to numerous agencies, including the California Department of Transportation, the San Diego Association of Governments, the Guam Department of Public Works, the Orange County Transportation Authority, the California Transportation Corridor Agencies, Los Angeles County Metropolitan Transportation Authority and many cities and counties in California. Galvan received a B.S. in civil engineering from San Diego State University.

Bottcher will be responsible for managing stormwater projects in Southern California. He has 32 years of experience in stormwater management, drainage design, hydraulics, hydrology, and stormwater treatment studies throughout California, with special expertise in stormwater systems along major highways and rail corridors. He has served as a program manager, project manager, and planning and design engineer for transportation drainage system design, storm water pollution prevention, hydromodification assessments, watershed management, flood control design, pump station design and groundwater/surface water hydrology. He previously served as the regional stormwater manager for a California engineering firm, providing engineering services to numerous agencies and municipalities in California and for clients in the Middle East. Bottcher holds bachelor’s and master’s degrees in engineering from Cornell University and is a registered professional engineer in the State of California.

Carty will provide architectural design services for transit and transportation projects in Southern California. He has over 38 years of experience managing architectural design for complex projects, including rail transit systems, fare collection studies and implementation, airport master plans, airport terminals and concourses, public safety facilities, vehicle maintenance facilities, air cargo and industrial storage facilities, parking decks, and water and wastewater treatment plants. Prior to joining WSP | Parsons Brinckerhoff, he served the Metropolitan Atlanta Rapid Transit Authority (MARTA) as deputy program manager and project manager for an automated fare collection system. Carty received M.A. and B.A. degrees from the College of Architecture at the University of Florida.

WSP | Parsons Brinckerhoff provides services designed to transform the built environment and restore the natural one. The firm’s expertise ranges from environmental remediation and urban planning to engineering iconic buildings and designing sustainable transport networks to developing the energy sources of the future and enabling new ways of extracting essential resources. Approximately 34,000 employees, including engineers, technicians, scientists, architects, planners, surveyors, program and construction management professionals, as well as various environmental experts work for this organization in more than 500 offices across 40 countries worldwide. For more information, visit wspgroup.com/usa.