What the Trees Can Tell Us

Many of us have learned that you can tell how old a tree is by counting its “rings.”  Tree-ring dating, or dendrochronology, was first discovered by Andrew Ellicott Douglass, an American astronomer who was born on July 5, 1867.

In 1894, Douglass reported his observation that tree rings were thinner in years with sunspot activity.  He was contacted by naturalist Clark Wissler, who was trying to determine the age of archaeological ruins in the American Southwest.

Over the next 15 years, the two men compared wooden beams excavated from various ruins, trying to cross-date them by comparing the rings.  Finally, in 1929 Douglass succeeded in assembling a continuous record of tree-ring data all the way back to the year 700 AD.  He predicted that his discovery would be “destined to hold a place comparable to Egypt’s Rosetta Stone.”

Dendrochronology works because a tree grows a measurable ring of new cells each year in its lifetime.  The technique is so precise, it is used to calibrate radiocarbon dating.  (Not all trees can be dated this way.  Some trees, including evergreens and olive trees, do not have annual growth rings.)

Scientists have used dendrochronology to reconstruct historical events including fires, hurricanes, volcanic activity, glacial movement and precipitation.

Researchers from the Slovak and Czech Republics studied how various weathering and environmental factors can affect the ageing of wood.  They used an Agilent HPLC chromatograph for sample analysis and Agilent ChemStation software for data collection.

Dendrochronology is also used as a tool against illegal logging, where authorities can match the ring “fingerprint” of tree stumps against lumber samples.  Researchers in Poland demonstrated that DNA markers can also be a precise and suitable tool.  They used an Agilent Bioanalyzer System and Agilent software to perform their genotyping.

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An Ancient Martian Lake May Have Contained Life

Since 2012, the Curiosity rover has been exploring Gale Crater on the planet Mars.  With five years of data now collected, scientists at the U.S. National Aeronautics and Space Administration strongly believe the crater once held water.  Even more astonishing, they believe the crater was once a habitable environment for life.

The announcement is based on rocks collected from the lowermost layers of Mount Sharp in the crater.

“These layers were deposited about 3.5 billion years ago, coinciding with a time on Earth when life was beginning to take hold,” says NASA’s Elizabeth Rampe.  “We think early Mars may have been similar to early Earth, and so these environments might have been habitable.” (NASA)

In one recent study, NASA scientists analyzed samples of mudstone from 14 different sites in Gale Crater.  (Mudstone is a fine-grained sedimentary rock originally formed from clay or mud.)  They detected trace gases including water, carbon dioxide, oxygen, hydrogen, sulfur dioxide, hydrogen sulfide, hydrogen chloride and nitric oxide.  They also detected organic fragments.

Water was the most abundant volatile released from all mudstone samples.  NASA’s analytical equipment included an Agilent Inert XL GC Mass Selective Detector.

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The Incredible Story of Vulcanized Rubber

Today we remember Charles Goodyear, an American self-taught chemist who transformed the rubber industry.

In the 19th century, the lucrative rubber trade was carefully controlled by South America, where natural rubber trees grew.  After Britain smuggled seeds to its colonies, rubber became a major crop in India and Malaysia.

The rubber industry took off because the substance was waterproof.  But consumers soon learned the limitations of natural rubber.  In the cold winter, it froze bone-hard.  In the hot summer, it melted into glue.  Factories went bankrupt and investors lost millions.

Enter Charles Goodyear, who was fascinated by rubber’s elasticity.  “There is probably no other inert substance which so excites the mind,” he said.  While serving time in debtor’s prison, he spent hours playing with a lump of raw rubber.

In 1839, Goodyear committed one of “history’s most celebrated accidents.”  While showing off a mixture of rubber and sulfur in a general store, Goodyear unwittingly dropped his concoction on a hot stove.  Instead of melting, the rubber became like leather.  Goodyear had accidentally invented vulcanized rubber.

On June 15, 1844, the self-taught chemist obtained a U.S. patent for his invention.

But Goodyear continued to operate on the edge of poverty, making ridiculously bad business deals.  He let go of his manufacturing interests, which would have made him millions.  He sent a sample to a British rubber company, who reverse-engineered the vulcanization process and beat Goodyear to an English patent.  Goodyear ended up fighting more than 30 patent infringement cases over his lifetime.

When he died in 1860, Goodyear was $200,000 in debt.  He never saw his invention skyrocket with the rise of the automobile industry.  In fact, he was never associated with the company that now bears his name – Goodyear Tire & Rubber Co., the world’s largest rubber business.

Today, a huge problem with vulcanized rubber is its impact on the environment, due to the limited ability to recycle or dispose of it.  Many discarded products are simply burned or buried.

Researchers in China looked for ways to overcome the non-reversible, permanent chemical structures caused by vulcanization.  They found that CuCL2 (copper chloride) can serve as a catalyst to rearrange the inherent sulfur crosslinked networks in vulcanized rubber.

They hope their work “will provide the basis for extending the service life and developing new recycling techniques of vulcanized rubber, which is produced, used and scrapped in large quantities every day.”

The researchers used an Agilent high-performance HPLC with a UV detector to monitor their chemical processes.

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Seven Decades After D-Day

On June 6, 1944, World War II Allies stormed the northern coast of German-occupied France.  D-Day was the largest single-day amphibious invasion of all time.  More than 160,000 Allied troops attacked 50,000 entrenched German troops.  Support included 5,000 ships and 13,000 planes.  Seven million pounds of bombs were dropped.

To this day, the sands of Omaha Beach retain small and microscopic beads of shrapnel, iron and glass.  They were created by the heat from mortar explosions.

More recently, the Canadian Government studied the long-term impact of live fire training on soil, surface water and groundwater.  Six military ranges were examined for two types of energetic compounds: propellants and high explosives.  Metal traces found in firing ranges included lead, chromium, copper, antimony, arsenic, zinc and cadmium.  Metal traces found in tank target areas included selenium.

Instruments used to analyze soil extracts included an Agilent HPLC equipped with a degasser, a quaternary pump and a UV diode array detector.

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