Tag Archives: acidity

Sticky Paper Offers Cheap, Easy Solution for Paper-Based Diagnostics

A current focus in global health research is to make medical tests that are not just cheap, but virtually free. One such strategy is to start with paper – one of humanity’s oldest technologies – and build a device like a home-based pregnancy test that might work for malaria, diabetes or other diseases.

A University of Washington bioengineer recently developed a way to make regular paper stick to medically interesting molecules. The work produced a chemical trick to make paper-based diagnostics using plain paper, the kind found at office supply stores around the world. (more…)

Read More

Increase in Metal Concentrations in Rocky Mountain Watershed Tied to Warming Temperatures

Warmer air temperatures since the 1980s may explain significant increases in zinc and other metal concentrations of ecological concern in a Rocky Mountain watershed, reports a new study led by the U.S. Geological Survey and the University of Colorado Boulder.

Rising concentrations of zinc and other metals in the upper Snake River just west of the Continental Divide near Keystone, Colo., may be the result of falling water tables, melting permafrost and accelerating mineral weathering rates, all driven by warmer air temperatures in the watershed.  Researchers observed a fourfold increase in dissolved zinc over the last 30 years during the month of September. (more…)

Read More

Acid Rain

UD’s long-term monitoring shows 60 percent reduction in acidity of Delaware rain

Several decades ago, precipitation in Delaware was among the most acidic in the country. Pollutants in the air reacted with rainwater to sprinkle sulfuric, nitric and carbonic acids onto the ground below, affecting crops and ecosystems statewide.

The scientific consensus is that pollution controls enacted through the Clean Air Act Amendments in the 1990s and other measures have helped decrease the acidity of rain by approximately 60 percent to less harmful levels, as reflected in data gathered nationwide and by UD researchers in Lewes, Del., as part of a longstanding study. (more…)

Read More

Researchers Find Unprecedented, Man-Made Trends in Oceans Acidity

Nearly one-third of CO2 emissions due to human activities enters the world’s oceans. By reacting with seawater, CO2 increases the water’s acidity, which may significantly reduce the calcification rate of such marine organisms as corals and mollusks, resulting in the potential loss of ecosystems. The extent to which human activities have raised the surface level of acidity, however, has been difficult to detect on regional scales because it varies naturally from one season and one year to the next, and between regions, and direct observations go back only 30 years.

By combining computer modeling with observations, an international team of scientists concluded that anthropogenic CO2 emissions, resulting from the influence of human beings, over the last 100 to 200 years have already raised ocean acidity far beyond the range of natural variations. The study is published in the January 22, 2012 online issue of Nature Climate Change. (more…)

Read More

Ocean Acidification Changes Nitrogen Cycling in World Seas

*New results indicate potential to reduce certain greenhouse gas emissions from oceans to atmosphere*  

Increasing acidity in the sea’s waters may fundamentally change how nitrogen is cycled in them, say marine scientists who published their findings in this week’s issue of the journal Proceedings of the National Academy of Sciences (PNAS).  

Nitrogen is one of the most important nutrients in the oceans. All organisms, from tiny microbes to blue whales, use nitrogen to make proteins and other important compounds.  (more…)

Read More

‘Undersea Methane Could be Contributor to Increased Ocean Acidity’

A North Carolina State University researcher is part of a team which has found that methane from “cold seeps” – undersea areas where fluids bubble up through sediments at the bottom of the ocean – could be contributing to the oceans’ increasing acidity and stressing already delicate undersea ecosystems. 

Oceanic microorganisms and bacteria survive by consuming dissolved organic carbon, or DOC. A byproduct of this consumption is CO2 – carbon dioxide – which, in large enough concentrations, makes seawater more acidic.  (more…)

Read More