PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Why do dew drops do what they do on leaves?

2012-01-13
(Press-News.org) Nobel laureate poet Rabindranath Tagore once wrote, "Let your life lightly dance on the edges of time like dew on the tip of a leaf." Now, a new study is finally offering an explanation for why small dew drops do as Tagore advised and form on the tips, rather than the flat surfaces, of leaves. It appears in ACS' journal Langmuir.

In the study, Martin E. R. Shanahan observes that drops of water have a preference for exactly where they collect on leaves as their surfaces cool in the morning and afternoon. Those droplets, which condense from water vapor — moisture — in the air, collect randomly across the surfaces of flat leaves. However, dew drops tend to accumulate at the tips of spindly leaves, even if that means defying gravity by moving upwards. He explains that an inherent "unwillingness" or "lack of necessity" of water drops to move on a dry surface governs their positioning on flat leaves, causing them to stay where they form. Dew's tendency to head to the end of finely pointed leaves, however, sent Shanahan looking for a different explanation.

The answer is based on the fundamental principle of free energy, that everything in nature seeks the lowest possible energy state. Shanahan modeled two types of dew drops on a theoretical (simplified) cone-shaped leaf: a thin, cylindrical sheath of water and a spherical drop centered on the cone's axis. In both cases, he found that the drop lowered its energy by moving toward the point of the leaf.

INFORMATION:

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society contact newsroom@acs.org.

END



ELSE PRESS RELEASES FROM THIS DATE:

Advance toward an imaging agent for diagnosing Alzheimer's disease

2012-01-13
Scientists are reporting development and initial laboratory tests of an imaging agent that shows promise for detecting the tell-tale signs of Alzheimer's disease (AD) in the brain — signs that now can't confirm a diagnosis until after patients have died. Their report appears in the journal ACS Medicinal Chemistry Letters. Masahiro Ono and colleagues explain that no proven laboratory test or medical scan now exists for AD, which is claiming an increasingly heavy toll with the graying of the world's population. Patients now get a diagnosis of AD based on their medical history ...

Best way to boost adult immunizations is through office-based action, study finds

2012-01-13
Promoting immunizations as a part of routine office-based medical practice is needed to improve adult vaccination rates, a highly effective way to curb the spread of diseases across communities, prevent needless illness and deaths, and lower health care costs, according to a new RAND Corporation study. Increasingly, vaccinations are being offered outside of physician offices at pharmacies, workplaces and retail medical clinics. Even so, office-based medical practice continues to be central to the delivery of recommended vaccinations to adults. "Regardless of where vaccines ...

Slippery when stacked: NIST theorists quantify the friction of graphene

Slippery when stacked: NIST theorists quantify the friction of graphene
2012-01-13
Similar to the way pavement, softened by a hot sun, will slow down a car, graphene—a one-atom-thick sheet of carbon with wondrous properties—slows down an object sliding across its surface. But stack the sheets and graphene gets more slippery, say theorists at the National Institute of Standards and Technology (NIST), who developed new software to quantify the material's friction. "I don't think anyone expects graphene to behave like a surface of a three-dimensional material, but our simulation for the first time explains the differences at an atomic scale," says NIST ...

NIST standard available for better diagnosis, treatment of cytomegalovirus

NIST standard available for better diagnosis, treatment of cytomegalovirus
2012-01-13
A new clinical Standard Reference Material (SRM) from the National Institute of Standards and Technology (NIST) will help health care professionals more accurately diagnose and treat cytomegalovirus (CMV), a common pathogen that is particularly dangerous for infants and persons with weakened immune systems. CMV is found in 50 to 80 percent of the population. It is a member of the herpes family of viruses that includes two herpes simplex viruses (the causes of cold sores and genital herpes), the varicella-zoster virus (the cause of chicken pox and shingles) and the Epstein-Barr ...

Stretching exercises: Using digital images to understand bridge failures

2012-01-13
With a random-looking spatter of paint specks, a pair of cameras and a whole lot of computer processing, engineer Mark Iadicola of the National Institute of Standards and Technology (NIST) has been helping the Federal Highway Administration (FHWA), in cooperation with the American Association of State Highway and Transportation Officials (AASHTO), to assure the safety of hundreds of truss bridges across the United States. Iadicola has been testing the use of a thoroughly modern version of an old technique—photographic measurement or "photogrammetry"—to watch the failure ...

NIST releases 2 new SRMs for monitoring human exposure to environmental toxins

2012-01-13
The National Institute of Standards and Technology (NIST), in collaboration with the Centers for Disease Control and Prevention (CDC), has developed two new Standard Reference Materials (SRMs) for measurements of human exposure to environmental toxins. Used as a sort of chemical ruler to check the accuracy of tests and analytic procedures, the new reference materials replace and improve older versions, adding measures for emerging environmental contaminants such as perchlorate, a chemical that the Environmental Protection Agency has targeted for regulation as a contaminant ...

Outlook for an industry that touches 96 percent of all manufactured goods

2012-01-13
The chemical industry, which touches 96 percent of all manufactured goods, is seeing some positive signs for 2012, although the overall outlook is not very rosy. Growing demand for chemicals used in agriculture, electronics, cars and airplanes will boost an industry that generates $674 billion in sales in the U.S. alone, but expiring patents and global economic woes will take a toll. These forecasts and others are in the cover story in the current issue of Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society, the world's largest scientific ...

'I feel your pain ...'

2012-01-13
Imagine the following scenarios: a co-worker is spoken to condescendingly, excluded from a meeting, or ignored by a supervisor. How does it make you feel? Do you feel differently depending on whether your co-worker is a man or a woman? According to a new study, workers who witness incivility towards colleagues feel negative emotions – especially when the incivility is aimed at workers of the same sex. The work, by Kathi Miner from Texas A&M University and Angela Eischeid from Buena Vista University, Iowa, is the first to look at the relationship between employees' observations ...

ALMA early science result reveals starving galaxies

2012-01-13
Astronomers using the partially completed ALMA observatory have found compelling evidence for how star-forming galaxies evolve into 'red and dead' elliptical galaxies, catching a large group of galaxies right in the middle of this change. For years, astronomers have been developing a picture of galaxy evolution in which mergers between spiral galaxies could explain why nearby large elliptical galaxies have so few young stars. The theoretical picture is chaotic and violent: The merging galaxies knock gas and dust into clumps of rapid star formation, called starbursts, ...

OU researchers predict the next big thing in particle physics: Supersymmetry

2012-01-13
A better understanding of the universe will be the outgrowth of the discovery of the Higgs boson, according to a team of University of Oklahoma researchers. The team predicts the discovery will lead to supersymmetry or SUSY—an extension of the standard model of particle physics. SUSY predicts new matter states or super partners for each matter particle already accounted for in the standard model. SUSY theory provides an important new step to a better understanding of the universe we live in. Howard Baer, Homer L. Dodge Professor of High Energy Physics in the OU Department ...

LAST 30 PRESS RELEASES:

Transforming treatment outcomes for people with OCD

Damage from smoke and respiratory viruses mitigated in mice via a common signaling pathway

New software tool could help better understand childhood cancer

Healthy lifestyle linked to lower diverticulitis risk, irrespective of genetic susceptibility

Women 65+ still at heightened risk of cervical cancer caused by HPV

‘Inflammatory’ diet during pregnancy may raise child’s diabetes type 1 risk

Effective therapies needed to halt rise in eco-anxiety, says psychology professor

Nature-friendly farming boosts biodiversity and yields but may require new subsidies

Against the odds: Endometriosis linked to four times higher pregnancy rates than other causes of infertility, new study reveals

Microplastics discovered in human reproductive fluids, new study reveals

Family ties and firm performance: How cousin marriage traditions shape informal businesses in Africa

Novel flu vaccine adjuvant improves protection against influenza viruses, study finds

Manipulation of light at the nanoscale helps advance biosensing

New mechanism discovered in ovarian cancer peritoneal metastasis: YWHAB restriction drives stemness and chemoresistance

New study links blood metabolites and immune cells to increased risk of urolithiasis

Pyruvate identified as a promising therapeutic agent for ulcerative colitis by targeting cytosolic phospholipase A2

New insights into the clinical impact of IKBKG mutations: Understanding the mechanisms behind rare immunodeficiency syndromes

Displays, imaging and sensing: New blue fluorophore breaks efficiency records in both solids and solutions

Sugar, the hidden thermostat in plants

Personality can explain why some CEOs earn higher salaries

This puzzle game shows kids how they’re smarter than AI

Study suggests remembrances of dead played role in rise of architecture in Andean region

Brain stimulation can boost math learning in people with weaker neural connections

Inhibiting enzyme could halt cell death in Parkinson’s disease, study finds

Neurotechnology reverses biological disadvantage in maths learning

UNDER EMBARGO: Neurotechnology reverses biological disadvantage in maths learning

Scientists target ‘molecular machine’ in the war against antimicrobial resistance

Extending classical CNOP method for deep-learning atmospheric and oceanic forecasting

Aston University research: Parents should encourage structure and independence around food to support children’s healthy eating

Thunderstorms are a major driver of tree death in tropical forests

[Press-News.org] Why do dew drops do what they do on leaves?