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The Engineer's Notebook

The Engineer's Notebook is a shared blog for entries that don't fit into a specific CR4 blog. Topics may range from grammar to physics and could be research or or an individual's thoughts - like you'd jot down in a well-used notebook.

Three Ways Lightning Has Left Its Mark

Posted July 19, 2016 1:19 PM by Chelsey H

With summer time comes thunderstorms. And while I don’t like being woken up in the middle of the night – I do enjoy watching the storm roll in from my front porch.

Lightning has shaped Earth, and life on Earth, for billions of years. Here are three ways lightning has left its mark on our home planet.

  1. Origin of life – Electricity is able to rearrange simple gases such as carbon dioxide, nitrogen, and water vapor and water into more intricate forms. A series of experiments shows that organics produced by lightning on our new planet most likely included amino acids and other fundamental components of living things and therefor served as the pool of ingredients from which life came.
  2. Early Microbes – All living things need nitrogen gas to make essential molecules like proteins and DNA. Nitrogen is extremely stable and lightening can break the bonded atoms and weld them onto nearby oxygen atoms. These oxides were usable by early microbes ensuring they had a renewable supply of nitrogen with which to continue reproducing. As microbes spread across the planet and increased in number, supplies of lightening-derived nitrogen oxides declined. This spurred the evolution of microbes to develop an internal way to convert nitrogen gas to workable ammonia.
  3. Forest Life – As soon as trees appeared, lightning began killing them. They are the principal natural means by which wildfires are ignited. And wildfires are important for forests. They provide homes and food for many animals and fungi. Other organisms reproduce as a direct results of burnt soil and charred wood. Production of fire-lined fungi is triggered when trees are damaged by fire and the dead leaves covering the forest floor, from which the mushrooms sprout, are burned away. Heat and smoke are also responsible for bringing about the germination of plant seeds which are impermeable to water until exposed to high heat.

Electrical currents have been linked to the creation and evolution of life on Earth. But it can also have devastating consequences – killing many of the quarter of a million people hit by lightning a year.

So maybe enjoy the thunderstorms from the safety of your front porch.

11 comments; last comment on 07/20/2016
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Is Helium Really In Short Supply?

Posted July 05, 2016 12:45 PM by Jonathan Fuller
Pathfinder Tags: helium mri shortage

Last week I had my first MRI as a result of some recent migraine-like headaches. It was pretty much all I’d anticipated: a Friday the 13th-style mask over my face, an uncomfortable 20 minutes in the tube, and an array of sounds that replicated—to quote my imaging tech—a bad drum solo. MRI has undergone some positive changes in its recent history, including the development of open and wide-bore scanners, but one aspect that hasn’t changed since its invention in 1971 is the use of liquid helium to cryogenically cool each scanner’s superconducting electromagnet.

Helium is the second-most abundant element in the observable universe, accounting for 24% of all baryonic matter, but usable terrestrial helium is much rarer. Global helium reserves have been in decline for years, and doctors and scientists have been criticizing the sale of helium balloons as wasting the gas critical to medical and scientific applications. Nobel laureate Robert Richardson considers the gas so precious that in 2012 he suggested raising the price of a child’s helium balloon to around $100 to reflect to true cost of helium.

Some of this panic was laid to rest last week, when a team from the UK and Norway announced the discovery of a massive natural store of helium in Tanzania’s Rift valley. They estimate that the area contains around 54 billion cubic feet of the gas, enough to cool 1.2 million MRI scanners. Natural helium supplies are typically uncovered by mistake during oil and gas exploration. But the UK scientists used expertise from Helium One, a Norwegian helium exploration company, to find that the Rift valley’s volcanic activity released helium from eons-old rocks buried deep underground. The released gas then became trapped in fields closer to the surface.

Helium has had some interesting supply chain issues in the US. The country began hoarding its supply—which accounts for about 70% of the world’s helium—during the airship craze of the early 1900s, establishing the National Helium Reserve in 1925 and banning exportation in 1927. The Reserve expanded throughout the Space Race and Cold War eras but poor financial management caused it to become economically insoluble. The 1996 Helium Privatization Act forced the Reserve to sell itself off at a (very low) formula-driven price beginning in 2005. But helium’s non-renewable nature resulted in shortfalls that have caused the gas’s private market price to rise 500% since 2000 or so. The 2013 Helium Stewardship Act mandated that the Reserve stick around until 2021, but many believe the liquidation of the reserve’s gas at ridiculously low prices prior to that legislation doomed US supply.

But the “we’re running out of a limited resource and we’re all going to die” argument is the same one commonly heard about fossil fuels, and in the same vein it has its detractors. They argue that mineral reserves are identified and prepared for use for the next several decades. So instead of panicking about limited supply, concerned individuals should remember that they’ve got the next several decades to identify and mine more supplies for the years following the exhaustion of the current reserve. Some also argue that helium is renewable, as it’s formed, albeit slowly, by the radioactive decay of plentiful uranium. One writer compared it to worrying about starving to death after you’ve eaten all the food in your refrigerator: instead of letting your fridge and stomach become empty, you just go out and find more before it reaches that point.

We can only hope that the Tanzania store drives He’s price down, or at least stops it from shooting up. In addition to cryogenic cooling of MRI scanners and NMR spectrometers, helium has important uses in controlled atmospheres, as a shielding gas in arc welding, and for industrial leak detection. The high cost of cryogenic cooling has made numerous exciting developments, such as superconducting power cables, unfeasible—perhaps this is a step in the right direction? Earlier this year we learned that China is looking to mine helium-3, a rarity on Earth, from the Moon’s crust to combat the supply problem. It doesn’t seem likely the Rift valley discovery will discourage that mission.

Image credit: Public domain

10 comments; last comment on 07/11/2016
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The Latest Tech for Sharkproofing Beaches

Posted June 20, 2016 11:04 AM by Jonathan Fuller
Pathfinder Tags: shark attacks sharks

Next month marks 100 years since the Jersey Shore shark attacks. A rogue shark (or multiple sharks, depending on which scientist you ask) killed four people and injured one during a two week span in early July 1916, at a time when a brutal heat wave and polio epidemic were driving thousands to resorts on the Atlantic coast. The attacks not only spurred panic and shark eradications on a national scale, they also immediately redefined the shark’s image from one of a timid sea creature to “the incarnation of ferocity.” Shark fever swept the nation, and soon newspaper cartoonists were using sharks to lampoon topics as diverse as German U-boats and prudish Victorian bathing suits.

Today, of course, ichthyologists know the truth about sharks and their behavior: they have lots of sharp teeth and occasionally attack without provocation. The popularity of films like Jaws and the annual sharkathon Shark Week, which kicks off June 25th this year, confirms that the mystique is still in vogue a century after the New Jersey incidents. While fatal shark attacks draw heavy media attention, they’re quite rare, with less than 100 total attacks reported each year. Still, those with a stake in beaches and resorts use a variety of technologies to prevent attacks.

A simple strategy for preventing attacks is to detect a shark’s presence and warn beachgoers to get the heck out of the water. In Cape Cod, Massachusetts, where a burgeoning seal population is drawing record numbers of great whites closer to shore, municipalities are posting traditional signage as well as large, dramatic billboards showing scary-looking sharks. For people whose heads are permanently looking down at their phones even at the beach, local group Atlantic Great White Conservancy is launching an app to allow visitors to track tagged great whites or quickly report seeing untagged ones. This year Cape Cod and other locales on the Eastern Seaboard may begin using drones to monitor shark populations close to shore. California and Australia already engage in drone monitoring, but the murky East Coast waters make visual sightings a challenge.

The other angle is to repel sharks from heavily populated beaches altogether. Traditionally, drum lines and shark nets were used for this purpose, but these methods endanger other non-harmful species, including non-aggressive sharks. South Africa’s KwaZulu Sharks Board is currently commercializing a shark-deterrent cable they tested in 2014. The cable features vertical “risers” that emit a low-frequency signal designed to confuse the shark’s sensory system. A shark’s nose contains an electroreceptive organ called the ampullae of Lorenzini that detects the potential difference between the voltage at the base of the electroreceptor and the voltage at the shark’s skin. The ampullae allow the shark to detect a far-off living creature’s heartbeat through the water, assisting with hunting and tracking. If successful the cable would be a huge improvement over shark nets: sharks have the greatest electrical sensitivity of any known animal, so the small electric fields won’t bother any other sea life or nearby humans. According to the Shark Board, the cable’s current is so small that a person accidentally contacting the cable would feel little more than a tingle.

Shark attacks are rare, but as evidenced by the recent Orlando alligator incident, most vacationers aren’t attuned to keeping their eyes peeled for local wildlife hazards. Development of sharkproof tech seems to benefit all involved, from the beachside communities who lose business at the first sign of a fin to the tourists who depend of them to stay safe.

Image credit: KwaZulu Natal Sharks Board

2 comments; last comment on 07/20/2016
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Coral Bleaching

Posted June 03, 2016 12:07 PM by BestInShow
Pathfinder Tags: bermuda coral bleaching sunscreen

Snorkeling along part of Bermuda's coral reef was one of the highlights of my recent trip to the island. Given the dire state of corals around the world, spending a little time amongst robustly healthy corals, and the resident fish, was a pleasure and a privilege. Why is Bermuda's reef in such good shape? Why are others, from the Great Barrier Reef to locations in the Florida Keys, dying? What, if anything, can we do to save what's left? Big questions, and articles abound that describe problems and potential solutions.

Rather than regurgitate a summary of the plethora of virtual ink dedicated to coral, I'll look at one less-obvious stressor of coral ecosystems. I'll also look at some ideas for coral restoration and ways to prevent further damage.

Coral Bleaching: Symptom of Stress

This year's El Nino event sparked the biggest coral die-off since 1998's El Nino. Pictures of swaths of bleached Great Barrier reef coral - estimated at one-third of the entire reef - show up with dismaying frequency. A number of news outlets published stories as I was writing this post. This phenomenon occurs when stressed corals expel the algae, called zooxanthellae, that live symbiotically within coral tissues. The algae are the coral animal's major food source, as well as the source of its color. NOAA's infographic below demonstrates this process. Soft corals are particularly prone to bleaching.

Infographic: NOAA

Stressors: Obvious and Not-So-Obvious

Those of you who are reading this can undoubtedly list some obvious anthropogenic environmental stressors.

  • Global warming and increased ocean temperature
  • Changes in ocean water chemistry - salinity levels and acidity
  • Pollution from waste runoff
  • Heat pollution from power plant cooling water discharge
  • Overexposure to humans via recreational scuba diving
  • Overfishing and use of destructive fishing methods
  • Loss of fish which clean seaweed from reefs

An additional and more subtle culprit is the chemicals in most sunscreens. The oldest research I found in a cursory web search is an from Environmental Health Perspectives published in 2008, "Sunscreens Cause Coral Bleaching by Promoting Viral Infections." The role of sunscreen hasn't gotten much attention until this latest episode of massive bleach-outs, though. At the time of publication, the authors estimated that 4,000 to 6,000 metric tons of sunscreen washes off swimmers in oceans worldwide. The more swimmers and divers cluster around reefs, the higher the concentration of washed-off Coppertone. And even a vanishingly small amount of the bad stuff can wreak havoc. Ironic that the stuff that protects humans from sunburn and skin damage helps cause coral to lose color and die.

The sunscreen chemicals that cause damage are paraben, a preservative; cinnamate and a camphor derivative, UVB blockers; and benzophenone, a UVA blocker. These chemicals do their dirty work by causing dormant viruses in coral's symbiotic algae

to wake up and replicate, eventually causing the algae to explode. The explosion propels the viruses into surrounding seawater where they can infect other corals. There is also evidence that chemicals alter the DNA of juvenile coral polyps, causing deformities and unviability.

Sunscreens with non-chemical UV blockers don't harm coral - at least, as far as we know today. These non-chemical blockers are our old friends zinc oxide, the stuff lifeguards paint on their noses, and titanium dioxide. Together these provide broad spectrum protection. A lot of websites advertise reef-safe and reef-friendly sunscreens and sunblocks.

An Aside about European Sunscreens

Recently I'd read that European and Australian scientists have access to much more effective sunblocking chemicals that are unavailable to those of us in the US. The story of why they are unavailable, despite 20 years' worth of user data demonstrating their safety and effectiveness, is too long for this post. Suffice it to say that testing takes money, either from the FDA or the product manufacturer, and evidently no one's interested enough to pony up.

I wondered if these FDA-banned ingredients are safer for coral than the three UV blockers listed above. I was thinking hey, not only are US citizens unnecessarily deprived of more effective sunscreens, we're also killing coral. Sure enough, as far as we know, none of the ingredients listed below harm coral or humans, at least not European and Australian humans. To add a touch of irony, a factory in South Carolina manufactures sunscreen with banned ingredients and ships it all to Europe.

  • Tinosorb M (UVA blocker)
  • Mexoryl XL (UVA blocker; SX available in the US but less effective)
  • Uvinul T 150
  • Uvinul A Plus
  • Uvasorb HEB
  • Parsol SLX

Coral Preservation and Growth

Stressed coral dies quickly and in large quantities. However, coral reefs grow agonizingly slowly. Large corals, like brain corals, grow 0.3 to 2 centimeters per year; soft corals, up to 10 centimeters a year. At this rate, a reef takes 10,000 years to form. A large barrier reef or an atoll can take 100,000 to 30 million years to form. Given this timeframe, preservation efforts are far more important than attempts to create new reefs, although there are ongoing efforts to provide structures, like sunken ships, for coral polyps to latch onto. Mr. Best in Show and I saw coral starting to grow on a shipwreck on our snorkeling trip; Bermuda has plenty of wrecked ships, most or all of which ran afoul of the reef.

Individuals can help keep coral healthy by using the right sunscreen and by refraining from touching coral when snorkeling or SCUBA-ing. Creating marine preserves where harmful activities are banned and human access is regulated is mandatory. Bermuda's government has passed laws to protect the island's reefs since the 1600s; this protection is one key factor in Bermuda reef health. Each of the factors leading to reef death can be addressed if enough political and ecological interest exist. For example, restoring populations of reef-cleaning fish directly improves reef health. Diligent monitoring programs, such as those managed by the Bermuda Reef Ecosystem Analysis and Monitoring (BREAM), discover potential threats and can avert significant damage - at least, that's what we hope. Global warming and carbon dioxide levels have already killed irreplaceable swaths of coral world-wide; what the future holds, we can't know.

References

http://coexploration.org/bbsr/coral/html/reef_formation.htm

https://en.wikipedia.org/wiki/Coral_reef#Formation

http://oceanservice.noaa.gov/education/tutorial_corals/welcome.html

Image credits

Bermuda_attractions.com

NOAA

SEOS

4 comments; last comment on 06/08/2016
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Are You A Workaholic?

Posted June 01, 2016 12:00 AM by Chelsey H

Are you a workaholic? Do you brag about it? Or are you trying to stop?

A study of 16,426 working adults in Norway studied the association between workaholism and psychiatric disorders, specifically ADHD, OCD, anxiety, and depression. Image credit

The study defined seven criteria when identifying addictive behavior. They are:

  • You think of how you can free up more time to work.
  • You spend much more time working than initially intended.
  • You work in order to reduce feelings of guilt, anxiety, helplessness or depression.
  • You have been told by others to cut down on work without listening to them.
  • You become stressed if you are prohibited from working.
  • You deprioritize hobbies, leisure activities, and/or exercise because of your work.
  • You work so much that it has negatively influenced your health.

Participants scoring 4 (often) or 5 (always) on four or more criteria identify a workaholic.

Researcher and clinical psychologist Specialist Cecilie Schou Andreassen, at the University of Bergen (UiB), and visiting scholar at the UCLA Semel Institute for Neuroscience and Human Behavior, said that "workaholics scored higher on all the psychiatric symptoms than non-workaholics."

  • 32.7 per cent met ADHD criteria (12.7 per cent among non-workaholics).
  • 25.6 per cent OCD criteria (8.7 per cent among non-workaholics).
  • 33.8 per cent met anxiety criteria (11.9 per cent among non-workaholics).
  • 8.9 per cent met depression criteria (2.6 per cent among non-workaholics).

People who work to the extreme may have deeper psychological or emotional issues. But whether the disorder leads to workaholism, or workaholism causes discorders it still unclear.

To be safe, make sure you relax this weekend!

To see the full study, visit here.

33 comments; last comment on 06/08/2016
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