Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Underwater sensor system could protect reservoirs, drinking water

20.03.2003


A sensor system that can autonomously, continuously and in real-time monitor streams, lakes, ocean bays and other bodies of liquid may help solve problems for environmentalists, manufacturers and those in charge of homeland security, according to Penn State engineers.



"The importance of developing a network sensor technology for operation in liquid environments has recently been highlighted in reports detailing the chemical slurry of antibiotics, estrogen-type hormones, insecticides, nicotine and other chemicals in the rivers of industrialized countries," says Dr. Craig A. Grimes, associate professor of electrical engineering and materials science and engineering. "However, analysis is still done by physically collecting samples and analyzing them back in the laboratory."

Monitoring of rivers downstream from sewage treatment plants, large city water supplies, or the composition of a local pond must all be done by hand. This expensive, time-consuming and sometimes dangerous practice is always time delayed and may miss short duration episodes of pollution or contaminants. Continuous, in-place monitoring would be the easiest, most timely and least expensive way to track changes in bodies of water.


However, underwater monitoring is hampered because water interferes with the radio transfer of information, the most common method used to transfer information in the air. The researchers, who include Grimes; Xiping Yang, William R. Dreschel, Kefeng Zeng and Casey S. Mungle, graduate students, electrical engineering, Penn State; and Keat G. Ong at SenTech Corporation, State College, Pa., looked at a hierarchical, acoustic method to transfer the information from the sensors to the person monitoring the water.

The researchers are looking at systems that can monitor temperature, salinity, acidity and specific chemicals. Some of the same researchers, in collaboration with Dr. Michael Pishko, associate professor chemical engineering and material science at Penn State, are working on an inexpensive, disposable sensor for ricin, the highly poisonous protein found in castor beans and thought to be a potential terrorism agent. Sensors also exist for other harmful chemicals.

In the aqueous sensor network system an uplink node floats on the water’s surface and transfers the aqueous network data from the water to the air, where it is received by the command computer.

Beneath the surface, layers of nodes/sensors monitor the water and pass the information along to the uplink. Sending a message from the farthest node direct to the uplink underwater is not possible because of the way water decreases the strength of the acoustic signal, so the researchers use a node-to-node multi-hop information transfer system.

"Node-to-node communication enables wide-area coverage using modest node power levels making practical long-term monitoring," Grimes reported in a paper in the journal Sensors.

After the network of nodes is deployed, floating anchored in place in the water, the system must set up an identification tree. The uplink node broadcasts a signal containing its identity. Every node that receives that broadcast marks the uplink node as its parent node. These nodes then broadcast a signal. Every node that receives that signal, and has not yet identified a parent node, will record the signaling node as its parent and then broadcast to even more distant nodes. A cascade of parent nodes eventually covers the entire system.

Periodically, the network sends data through the system. Each node sends its sensor data to its parent node. That node sends the received data and its own data to its parent node until all the data are received by the uplink node, which converts the signal from acoustic to radio frequency and sends the information through the air to the command, or central, computer for display and evaluation.

The host node stores the sensor data from all the nodes in its memory preserving the identity of the node that produced the data so that water-monitoring personnel can track unusual readings or contaminants to their source location.

The researchers designed the nodes so that the chemical sensors are immersed in water separate from the communication electronics, making it easy to change the sensors on the nodes without having to alter the signaling network.


The National Science Foundation supported this work.

Andrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu/

More articles from Process Engineering:

nachricht NRL develops laser processing method to increase efficiency of optoelectronic devices
16.04.2019 | Naval Research Laboratory

nachricht Hollow structures in 3D
29.03.2019 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Energy-saving new LED phosphor

The human eye is particularly sensitive to green, but less sensitive to blue and red. Chemists led by Hubert Huppertz at the University of Innsbruck have now developed a new red phosphor whose light is well perceived by the eye. This increases the light yield of white LEDs by around one sixth, which can significantly improve the energy efficiency of lighting systems.

Light emitting diodes or LEDs are only able to produce light of a certain colour. However, white light can be created using different colour mixing processes.

Im Focus: Quantum gas turns supersolid

Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.

Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

Proteins stand up to nerve cell regression

24.04.2019 | Life Sciences

New sensor detects rare metals used in smartphones

24.04.2019 | Life Sciences

Controlling instabilities gives closer look at chemistry from hypersonic vehicles

24.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>