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Make Mine Water

Posted June 23rd, 2009 by Bruce Bennett

When the time comes to kick back and relax, my wife and I enjoy vacationing in Aruba. Located in the southern Caribbean about 15 miles off the coast of Venezuela, this tiny (75 square miles) desert island has a lot going for it, starting with the climate. Being situated outside of the Caribbean’s notorious hurricane belt, the weather is monotonously the same every day – sunny, with an average temperature of 80 – 85 degrees Fahrenheit and a nice, cooling breeze provided by the constant trade winds that blow across the island. In the last 50 years Aruba has grown from being a sleepy little island whose main source of income was oil refining to a world-class resort destination whose main source of income is tourism.

As one might expect on a desert island, fresh water is scarce. Rainfall averages less than 20 inches per year, which may be ideal for sun worshippers but it’s not real conducive to human survival. Or tourism. For one thing, it’s kind of hard to make those fruity, umbrella-topped rum drinks tourists like so much without fresh water. So Aruba solved the problem by building one of the largest water desalination plants in the world. Water-en Energiebedrijf Aruba N.V., as the plant is officially known – or WEB for short – currently sucks up sea water and converts it into roughly 9.8 million gallons of fresh water per day using a multi-stage flash (MSF) distillation system. From what I’ve read, the plant produces some of the purest, highest quality drinking water in the world, and my taste buds would not disagree. The plant also doubles as the island’s source of electricity, cranking out somewhere in the area of 60 MW a day.

Considering the escalating need for, and diminishing supply of, clean drinking water in many parts of the world, the obvious question is, if a tiny island like Aruba can successfully convert enough seawater into fresh water to sustain its 100,000 inhabitants and more than 700,000 tourists who visit each year, why can’t other countries? God knows there’s enough seawater in the world, and we obviously have the technology.

Unfortunately, the solution isn’t quite as simple as it sounds. Water desalination, it seems, is a very energy-intensive, expensive process. Most estimates put the average cost to produce 1 acre-foot (approx. 325,851 gallons) of desalinated water at anywhere from $800 to $1400. And that’s not counting the cost to build and maintain the plant and infrastructure. Some of the countries who need fresh water the most also happen to be some of the poorest countries on Earth.

Then there are the environmental impact considerations. Depending on the type of energy used to run the plant, greenhouse gas emissions or nuclear waste could be a problem. And what do you do with all that salt you remove from the water? Dumping it back into the ocean could raise local salt concentration levels, adversely affecting marine life.

None of these problems is insurmountable and, as they say, “necessity is the mother of invention.” What’s important is that we have the technology now to convert seawater into drinking water if we have to. The economics of doing so will work themselves out as the need increases. Just ask anyone serving fruity, umbrella-topped rum drinks to tourists in Aruba.

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Sensors Connect the World

Posted June 11th, 2009 by Spencer Chin

Connectivity is the order of the day in today’s shrinking world, and the world of sensors is no exception. At the just-completed Sensors Expo in Rosemont, IL, there was no shortage of sensor products touting advances in miniaturization and performance. But more important, sensors are taking on the role of being key detection and control nodes in manufacturing, transportation, energy monitoring, and medical networks.

This brave new world for sensors was highlighted in a keynote speech by Beth Wozniak, President of Sensing and Control for Honeywell Automation and Control Solutions. Not only does Wozniak foresee sensors going into more applications than ever, she believes sensors will play a pivotal role in improving our health and well-being, boosting economic productivity, and lowering energy costs.

As an example, Wozniak said sensors could monitor the effects of prescription doses. The information sensors provide would enable doctors to adjust dosage levels, without requiring patients to continually visit medical facilities. Home health care would improve and overall health care costs could be reduced.

In transportation, Wozniak suggested sensors could monitor flow in bus-only lanes and signal control systems to allow automobiles to use those lanes, if congestion was severe. In agricultural facilities, Wozniak believes sensors could team with video cameras to monitor soil conditions to improve crop control and yield.

One key to making this all happen, according to Wozniak, is continuing improvements in wireless sensor networks. In the future, sensor nodes on these networks would not only detect abnormal conditions but also incorporate the intelligence to make control decisions and thus reduce processing overhead on the central controller. To become feasible, sensor networks would have to address challenges in power, security, and of course, cost.

Judging from the exhibits and conference sessions at Sensors Expo, Wozniak’s vision is becoming a reality. Sprinkled among the dozens of sensor vendors at the show were companies showing wireless networking solutions using high-speed protocols. Several conference sessions addressed issues such as low-power wireless sensing, wireless standards, and the development of ‘smart’ sensors.

The future of sensors is unfurling before our eyes.

Sensors, Robots In Rosemont

Posted June 4th, 2009 by Spencer Chin

The Donald Stephens Convention Center in Rosemont, IL, will be buzzing next week with Sensors Expo and Conference, the key industry event focusing on sensors and sensor integrated systems. Being held June 8 through 10, the show will highlight the key advances in sensor technology that are finding their way into applications ranging from consumer to industrial to medical.

The exhibitor portion of Sensors Expo features 175 vendors of sensor-related products, representing who’s who in the sensors industry. The conference portion encompasses 18 sessions. Familiar topics such as sensor interfaces, position sensing, and sensor systems design will be covered alongside newer topics such as wireless sensor networks and novel approaches to biodetection.

There will also be two keynote sessions. On Tuesday, June 9 at 9 am, Dr. Kevin Grazier, NASA Jet Propulsion Laboratory Investigation Scientist and Science Planning Engineer for the Cassini/Huygens Mission to Saturn and Titan, will overview the technical hurdles involved in implementing a spacecraft mission to Saturn and discuss plans for Cassini’s future. On Wednesday, June 10, at 9 am, Beth Wozniak, President of Sensing and Control at Honeywell Automation and Control Solutions, will discuss the important role sensor networks are playing in linking factories and communication systems across the globe, leading to a world of pervasive sensing.

This year, Sensors Expo will co-locate with another show, the International Robots, Vision, and Motion Control Show. Over 150 companies representing a range of robotic, machine vision, and motion control technologies will be on the exhibit floor. The show’s highlights include a keynote on military robotics by Ellen Purdy, Enterprise Director, Joint Ground Robotics OUSD for the U.S. Army, on Wednesday at 9 am.

I have a number of meetings scheduled at both shows next Tuesday and Wednesday and expect to uncover some new and interesting information to share with you.

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