Science & Technology
08 Nov 2013:
Antarctic Researchers Discover
Strips of Rock That Slow Flow of Glaciers
Narrow ribs of dirt and rock beneath Antarctic glaciers help slow the glaciers' flow into the sea, according to new research
from scientists at Princeton University and the British Antarctic Survey. Using satellite measurements of the Pine Island Glacier and Thwaites
Glacier, both in West Antarctica, researchers discovered bands they call "tiger stripes" underlying the glaciers. The stripes serve as zones of friction and prevent sliding, much like non-slip flooring, the researchers report in Science
. Understanding the factors that control the glaciers' flow to the sea is important because their melting contributes significantly to sea level rise. The Pine Island and Thwaites glaciers are particularly important, as together they've contributed about 10 percent of the observed global sea level rise over the past 20 years.
24 Oct 2013:
Electric Vehicle Sales
On the Rise in 2013, New Analysis Shows
By the end of August, 59,000 electric vehicles had been sold in the U.S. this year — more than during all of 2012, a new report from the Union of Concerned Scientists (UCS)
shows. Over the past three years,
Americans purchased more than 140,000 electric vehicles (EVs), which have saved more than 40 million gallons of gas each year, the report notes. California is the leader, with 29 percent of all U.S. plug-in vehicle purchases made this year. EV sales rates have more than doubled in that state over the past year, according to the report. Although East and West coast cities continue to be hotspots for EV sales, purchases are picking up in cities like Denver, St. Louis, and Dallas, the report says
22 Oct 2013:
Southern Amazon Rainforest
In Danger as Dry Season Expands, Study Says
The dry season in the southern part of the Amazon rainforest is lasting three weeks longer than it did 30 years ago, putting the forest at higher risk for fires and tree mortality, according to new research from the University of Texas
. The most likely culprit is global
warming, says lead researcher Rong Fu. Even if future wet seasons become wetter, rainforest soil can only hold so much water, Fu explained. That water must sustain the forest throughout the entire dry season, and as the dry season lengthens the rainforest becomes increasingly stressed, vegetation growth slows, and the risk of fire rises. During a severe drought in 2005, the Amazon actually released a large amount of carbon dioxide into the atmosphere, rather than acting as a net carbon sink. Should dry seasons continue to expand, conditions like those in 2005 could become the norm, accelerating the buildup of CO2 in the atmosphere, the researchers wrote in the Proceedings of the National Academy of Sciences
17 Oct 2013:
Animals May Play Significant
Role in Carbon Cycling, Researchers Say
Wildlife may play a more important role in the global carbon cycle than researchers have previously given it credit for, according to a study
from an international group of scientists. Although models generally include
Muskoxen in Alaska
carbon cycling by plants and microbes, they often ignore the ways animals contribute to the process. That's a mistake, says Oswald Schmitz, an ecologist at Yale who led the study, because the actions of wildlife can affect carbon cycling through "indirect multiplier effects." For example, the massive loss of trees in North America triggered by the pine beetle outbreak has caused a net carbon change on scale with British Columbia's current fossil fuel emissions, the researchers reported in Ecosystems
. And in the Arctic, where about 500 gigatons of carbon is stored in permafrost, large grazing mammals like caribou and muskoxen can help maintain the grasslands that have a high albedo and thus reflect more solar energy. "We're not saying that managing animals will offset these carbon emissions," Schmitz said. "What we're trying to say is the numbers are of a scale where it is worthwhile to start thinking about how animals could be managed to accomplish that."
10 Oct 2013:
Carbon Capture and Storage
Projects Lagging Worldwide, Study Finds
Major projects aiming at capturing and burying carbon dioxide underground have slowed worldwide, according to a study by the Global CCS Institute in Australia
. Despite the common view among experts that carbon
Otway CCS project, Victoria, Australia
capture and storage (CCS) technologies could play a crucial role in slowing the atmospheric buildup of greenhouse gases, the number of major CCS projects fell from 75 to 65 over the past year. Although the U.S. currently leads the world in CCS projects, most of them involve pumping carbon into old oil wells to stimulate additional oil production. China, the world's largest producer of carbon dioxide, seems poised to become the new leader in CCS, with 12 projects in the works, the study noted. A major hurdle for the growth of CCS has been the lack of investments in projects based on new technologies, the analysts said. CCS technology has so far not proven to be commercially viable, The New York Times
09 Oct 2013:
Antarctic Research Operations
To Be Halted Amid U.S. Government Shutdown
The National Science Foundation (NSF) says it is curtailing the 2013-2014 Antarctic research season because the U.S. government shutdown has delayed funding for operations there. The U.S. Antarctic
Program, which is managed by the NSF, announced yesterday
that the three U.S. research stations, ships, and other facilities there will switch to "caretaker status" when funds are exhausted around October 14. All research activities not essential to human safety and preservation of property will be suspended, according to the statement. Because of the remote location and long lead time necessary for planning and travel, the NSF has already started the process of shuttering research facilities. Once funding is restored, some research operations could be restored, the U.S. Antarctic Program said. Around 700 scientists typically travel to the continent between October and February each year, according to Nature
04 Oct 2013:
New Hurricane Sandy Models
Are Most Detailed Visualizations To Date
The most striking visualizations to date of Hurricane Sandy, which devastated parts of the U.S. East Coast last year, show in great detail
the storm's evolution and path. Developed using state-of-the-art computer models
at the National Center for Atmospheric Research (NCAR)
, the images are based on data with spatial resolution 5,500 times greater than NOAA's highest-resolution hurricane forecast model. The visualizations show how several well-studied weather phenomena coincided to create the superstorm. They also show how, about a day before it made landfall, cool air began to envelop the storm's warm core. This ultimately tempered Sandy's power, but it also could have intensified winds at the storm's lower levels. The computer model includes 150 layers of vertical data, which means the model calculated weather conditions at more than 4 billion points within the storm each second, said meteorologist Robert Henson of the University Corporation for Atmospheric Research, which manages NCAR.
19 Sep 2013:
Fracked Shale Formations
Could Store Carbon Dioxide, Study Says
Storing carbon dioxide in the same shale formations that produce natural gas may be an effective way to sequester carbon dioxide produced by fossil fuel-burning power plants, according to a U.S. study
. Computer models by researchers at the University of
Virginia suggest the Marcellus Shale, a 600-square-mile formation in the northeastern U.S. that is a center of hydrofracturing natural gas, is capable of storing half the CO2 emitted by U.S. coal plants from now to 2030. Fracked shale wells are good candidates for carbon storage because CO2 can be injected in much the same way that natural gas was extracted, the researchers say. Fracking involves injecting pressurized fluids in wells to fracture the shale rock, which creates cracks that let gas seep out. The authors of this study suggest those networks of cracks could be filled with CO2 before sealing the natural gas wells.
10 Sep 2013:
New Prize is Created to
Improve Measurements of Ocean Acidity
Philanthropist Wendy Schmidt is offering $2 million in prize money
to inventors who can develop inexpensive and easily deployable sensors to measure ocean acidification. The Wendy Schmidt Ocean Health X Prize
is offering $1 million to the team that invents the most accurate sensors to measure the ocean’s acidity and $1 million to the team that devises the most affordable and easy-to-use sensors. Biologist Paul Bunje, a senior executive for oceans at the X-Prize Foundation, said that because current ocean acidity sensors can cost more than $5,000, very little is known about the pace of ocean acidification in various regions and depths. The goal, said Bunje, is to deploy many thousands of sensors worldwide. Rising concentrations of atmospheric carbon dioxide mean that more CO2 is being dissolved in the oceans, steadily making them more acidic.
09 Sep 2013:
Grid-Scale Batteries Make Sense
For Solar Energy, But Not Wind, Study Says
When renewable energy sources such as solar and wind farms generate more electricity than consumers need, storing the excess doesn't always make sense, say researchers from Stanford University
. Large, grid-scale batteries capable of storing the extra electricity are resource-intensive and costly to manufacture and maintain — sometimes more so than the energy they're used to store. "You wouldn't spend a $100 on a safe to store a $10 watch," said Michael Dale, who co-authored the study in the journal Energy & Environmental Science
. "Likewise, it's not sensible to build energetically expensive batteries for an energetically cheap resource like wind." Economically, it makes more sense to shut down wind energy production when consumer demand is low than it does to maintain battery systems to store excess wind energy, the study said. But battery storage does make sense for photovoltaic systems, the researchers say
, because solar panels and solar farms require more energy to build and maintain.
06 Sep 2013:
Immense Pacific Volcano Is
Among The Largest in the Solar System
A massive underwater volcano the size of New Mexico has been discovered 1,000 miles east of Japan, Nature Geoscience reports
. Covering an area of 120,000 square
miles, the volcano is 50 times larger than Hawaii's Mauna Loa, making it the largest volcano on Earth, according to a team of researchers
from the U.S., Japan, and the U.K. The newly discovered volcano, named Tamu Massif, is only 25 percent smaller than the immense volcano on Mars, Olympus Mons, which is large enough to spot with a backyard telescope. Tamu Massif is a shield volcano, with a low, broad shape and gradually sloped flanks. Its name derives from Texas A&M University, where the lead researcher taught for three decades.
How High Tech Is Helping
Bring Clean Water to Rural India
Social entrepreneur Anand Shah runs Sarvajal, a company that seeks to bring clean water to remote villages in India by deploying solar-powered “water
ATMs,” which dispense water to residents with the swipe of a prepaid smart card. Sarvajal, launched in 2008, currently serves more than 110,000 rural customers and is now is moving into India’s urban slums, where people often spend hours a day waiting for trucks to deliver clean water. In an interview with Yale Environment 360
, Shah talks about the challenges of expanding access to clean water in India and the lessons his company has learned from its first five years of operation. “The solutions came from what we actually saw in the field, rather than being invented elsewhere,” he says, “and that’s what makes it work.”
Read the interview.
26 Aug 2013:
Ocean Acidification Could
Amplify Global Warming, Study Says
The increasing acidification of the world’s oceans caused by rising concentrations of atmospheric carbon dioxide not only poses a threat to marine creatures, but also could lead to an intensification of planetary warming,
according to a new study. A team of U.S., British, and German researchers conducted experiments in seawater enclosures, known as mesocosms
, showing that the increasing acidification of the ocean leads to a drop in production of an important sulfur compound, dimethylsulphide, or DMS. Marine emissions of DMS are the largest natural source of atmospheric sulfur,
and those sulfur aerosols play an important role in reflecting the sun’s energy back into space and cooling the planet. Reporting in the journal Nature Climate Change
, the scientists found that when they created acidic conditions in the seawater enclosures that match pH levels expected in 2100, emissions of DMS fell by roughly 18 percent. The scientists said their study was the first to prove the link between rising ocean acidification and the potential decrease in planet-cooling sulfur dioxide aerosols.
22 Aug 2013:
Satellite Images of Fire
Help Guide Restoration Projects
The U.S. Forest Service is using NASA satellite images of fires in the American West to help rapidly restore burned areas
before the upcoming rainy season causes floods and washouts that could threaten lives and property.
This image of the Silver Hill fire in New Mexico, which burned 138,000 acres in June, was taken using infrared technology — mounted on NASA’s Landsat satellite — that distinguishes between vegetated and burned areas. The most severely burned areas are depicted in red, followed by areas of moderate-severity burn in yellow and low-severity burn in green. NASA began supplying the Forest Service with images as the fire raged, and in the wake of the fire the Forest Service has undertaken restoration efforts to stabilize the ground and prevent flooding during the rainy season in late summer.
14 Aug 2013:
Bears Using Wildlife Corridors
In Canadian Park, Genetic Tests Show
Genetic testing has revealed that bears in Canada’s Banff National Park routinely cross the bridges and underpasses along the Trans-Canada Highway
, evidence that the ecological corridors provide safe
A grizzly passes through a Banff underpass
passage along a busy roadway that otherwise threatens to fragment wildlife habitat
. Using 420 wire snag “hair traps” and 497 rub trees at 20 crossings to collect hair from passing bears, researchers from Montana State University determined that 15 individual grizzly bears and 17 individual black bears used the passages over a three-year period. According to researchers, those accounted for about 20 percent of the park’s bear populations, suggesting the passageways are providing enough connectivity to maintain a healthy ecosystem for bears and other large mammals. Twenty-five passages were installed in the 1990s
when the government widened a highway that includes a 100-mile stretch bisecting Banff.
12 Aug 2013:
Live Video Stream Provides
Rare Glimpse of Deepsea Marine World
The U.S. National Oceanic and Atmospheric Administration (NOAA) this month is streaming online a live video feed from the deep-sea canyons off the northeastern U.S. coast
, offering a real-time glimpse of
the marine diversity on the ocean floor. In a 36-day expedition launched last month
, NOAA researchers are using a remote-controlled vehicle tethered to the research ship Okeanos Explorer
to capture video footage of rare marine creatures, deep coral communities, and cold vents, or seeps, from largely unexplored U.S. waters. NOAA is employing a remotely operated vehicle, known as Deep Discoverer
, and a sophisticated camera sled to explore and broadcast video — accompanied by real-time narration from scientists — from depths of up to 6,000 meters, or nearly 20,000 feet. The project will continue until August 17.
07 Aug 2013:
Mimicking Cactus Design,
Scientists Devise Oil Spill Cleanup Method
Chinese researchers have developed a method of removing oil from polluted water using tiny barbed spikes that mimic the natural design of a cactus
The cactus opuntia microdasys
Writing in the journal Nature Communications
, the Beijing-based researchers describe how arrays of tiny copper spikes, similar to the cone-shaped spikes of a type of cactus known as Opuntia microdasys
, are able to collect micron-sized oil droplets that might otherwise be difficult to remove from water. The copper spikes are extremely thin at their point but get wider as they get closer to the base, creating a pressure difference that pulls droplets of oil toward the artificial skin-like surface. The oil then coalesces at the base of the cone, which can then be removed from the water. “Each conical needle in the array is a little oil collection device,” said Lei Jiang, lead author of the report. In tests, the researchers found that the needle arrays were able to remove about 99 percent of oil content from water, suggesting that the design could lead to new methods of cleaning up oil spills.
05 Aug 2013:
New Deep-Rooted Rice
Shows Greater Resistance to Drought
Japanese scientists say they have developed a rice plant with deeper roots
that could yield a more drought-resistant variety of rice. Writing in the journal Nature Genetics
, a team of scientists describes the discovery of gene that causes a rice strain known as Kinandang Patong, grown in the dry upland of the Philippines, to send longer roots into the soil, allowing the plant to extract water from deeper soil layers. After splicing the gene with a commonly grown rice strain, called IR64, the scientists found that the maximum root depths were more than twice those of the typical plants. After exposing both strains to moderate and severe drought conditions, the researchers found that yields of the standard variety fell significantly in moderate drought conditions and collapsed altogether in severe drought, while the modified strains were not affected by moderate drought and yields declined only 30 percent in severe drought.
01 Aug 2013:
Whales Shown to Flee
From Mid-Frequency Military Sonar
Two new studies show that the use of military sonar can provoke whales to flee
, providing evidence that the naval operations may be a factor in mass strandings of whales and dolphins worldwide. According to one study
A blue whale
most marine mammal strandings related to naval sonar exercises involve beaked whales, a notoriously shy species that responds to noise levels well below those used by the U.S. Navy. Scientists believe the beaked whales may interpret the sonar noises as the sounds of killer whales. A separate study
found that even mid-frequency sonar affected the behavior of blue whales, the largest animals on earth, especially during feeding. After exposing tagged blue whales to simulated military sonar and other mid-frequency sounds, the animals often ceased feeding, increased swimming speeds, and traveled away from the sound. “Noise pollution threatens vulnerable populations, driving them away from areas important to their survival, and at worst injuring or even causing the deaths of some whales and dolphins,” Sarah Dolman of the non-profit group Whale and Dolphin Conservation told the Guardian
31 Jul 2013:
Desert Tree Plantings
Could Lower Atmospheric CO2 Levels
The large-scale planting of jatropha trees in the world’s arid regions could help reduce atmospheric levels of carbon dioxide
, a new study says. Using computer models and data from plantations in Egypt, India, and
Madagascar, a team of German scientists calculated that plantations of the durable, scrubby jatropha — which can also be used as a biofuel — could capture 17 to 25 tons of carbon dioxide per hectare annually. Jatropha is particularly suited for so-called “carbon farming” because it can grow in hot, dry regions where the soil is unsuitable for food crops, according to the study, published in the journal Earth System Dynamics
. In addition, the researchers estimate that there are about 1 billion hectares of “unused and marginal” land suitable for cultivating such tree plantations. Since jatropha trees do require some water, the authors suggest they should be planted near coastal regions where desalinated seawater could be accessible.
29 Jul 2013:
Wired Honeybees Show
Harmful Impacts of Pesticides on Navigation
Using tiny radar antennae glued to the backs of honeybees, European scientists have found that bees exposed to neonicotinoid pesticides were more likely to become disoriented
and separated from their hives.
Honeybee wired with radar antennae
After attaching the small transponders to 200 bees, including some that were fed pesticide-laced syrup, scientists discovered that the exposed bees had difficulty navigating and were unable to retrace the path back to their hives. “We find the control bees are just fantastic — they use their landscape and their vector memory and they do fine,” Randolf Menzel, an insect neurobiologist at the Free University in Berlin, told the London Telegraph
. “The treated bees, depending on the doses of the substance, are more confused.” The findings appear to support a theory that neonicotinoids make bees more vulnerable to pathogens and could be a factor in so-called “colony collapse disorder,” a phenomenon that has decimated honeybee populations
in recent years.
26 Jul 2013:
Parched New Mexico Reservoir
Reveals Effects of Prolonged Drought
A pair of satellite images released by NASA this week
shows the effects of a severe drought on New Mexico’s largest reservoir, where water levels are at their lowest
levels in four decades. Earlier this week, the U.S. Army Corps of Engineers estimated that Elephant Butte reservoir in southern New Mexico was holding about 65,057 acre-feet of water, only 3 percent of its capacity of 2.2 million acre-feet, largely as a result of prolonged drought conditions and unusually low spring snowmelt from nearby mountains. That represents the lowest water levels in the reservoir since 1972. From the mid-1980s to 2000 the reservoir was nearly filled to capacity, as illustrated in a 1994 satellite image, top, released by NASA. The reservoir, fed by the Rio Grande, provides water for about 90,000 acres of agricultural land and about half the city of El Paso, Tex.
25 Jul 2013:
Mapping of Oil Palm Genome
Could Boost Productivity of Key Crop
Scientists say they have identified the gene responsible for the yield of oil palm crops, a discovery that could boost the productivity of the world’s top source of
vegetable oil and help reduce the size of oil palm plantations in the world’s tropical regions. Writing in the journal Nature
, Malaysian and U.S. researchers describe the mapping of the genome of the oil palm, whose products are used in everything from food to cosmetics to biofuels. According to the scientists, the so-called “shell gene” controls “how the thickness of its shell correlates to fruit size and oil yield
.” The fruit of the African palm oil tree comes in three varieties
: a thick-shelled dura, a shell-less pisifera, and a thin-shelled tenera, which produces a greater oil yield. According to scientists, the shell gene plays a key role in a mutation that produces the more commercially productive tenera variety.
17 Jul 2013:
New App Identifies Species
By Recordings of Their Vocalizations
A new app is enabling scientists and the public to automatically identify frogs, birds, insects, monkeys, and other animals by recording their vocalizations.
Scientists at the University of Puerto Rico have created a system called the Automated Remote Biodiversity Monitoring Network (ARBIMON) that enables them to place inexpensive, solar-powered technology in the field and record the sounds of creatures that are often difficult to see or locate in their natural environment. The devices, which include I-Pods, can make 144 one-minute recordings per day and transmit them to a base station miles away. Using the ARBIMON system
, scientists have already made more than 1 million recordings in Puerto Rico, Hawaii, Arizona, Costa Rica, and Brazil that can be listened to online. Researchers say the new system will greatly enhance their ability to do field research and to monitor the presence and activity patterns of species.
10 Jul 2013:
Massive Iceberg Calves
Off Antarctica’s Pine Island Glacier
A massive chunk of Antarctica’s fastest-moving ice stream, the Pine Island Glacier, dropped into the Amundsen Sea this week
, nearly two years after
Click to enlarge
Alfred Wegener Institute/German Space Agency
Pine Island Glacier, 2011-2013
scientists first observed a crack in the glacier tongue. German scientists, who have been tracking the progress of the ice mass since NASA satellites first observed the crack in 2011, say the calved iceberg measured 720 square kilometers (278 square miles). There is no conclusive proof that climate change triggered the ice break, said Angelika Humbert, an ice researcher at the Alfred Wegener Institute. But shifting wind patterns around Antarctica are bringing warmer waters to the surface of the Southern Ocean in West Antarctica, which is hastening the thinning of some glaciers. Humbert said those warmer waters are causing the Pine Island Glacier to flow more rapidly into the Amundsen Sea.
09 Jul 2013:
Coal Emissions in China Slash
5.5 Years off Life Expectancy, Study Says
The life expectancy of people living in northern China is 5 ½ years less than in southern China
as a result of the north’s notoriously bad air pollution, largely due to the burning of coal, according to a new study. In an analysis
of air quality recordings from 90 Chinese cities from 1981 to 2000 and mortality data from the 1990s, a team of researchers estimated that high air pollution will cost the roughly 500 million people living north of the Huai River a combined 2.5 billion years of life expectancy compared with people living in the south. Writing in the Proceedings of the National Academy of Sciences
, the researchers say increased mortality, attributable to cardiorespiratory illness
, is the unintended consequence of a Chinese policy that from 1950 to 1980 provided free coal for boilers in cities north of the Huai, but not for those living in the south.
08 Jul 2013:
Crowdsourcing Project Targets
Open-Source Tool for Ocean Research
A team of marine researchers is developing a blueprint for an inexpensive tool to collect oceanographic data, a venture they hope will make ocean science more accessible
to other scientists, educators, and marine enthusiasts. Using an open-access model
, the researchers hope to build their own CTD, a widely used oceanographic instrument that collects information on ocean temperature, depth, salinity, and density. While CTDs are vital to marine research, the technology can be prohibitively expensive for some “citizen scientists,” with costs running $5,000 to $25,000 per instrument. Traditional CTDs are small, cylindrical instruments that are dropped from boats and relay data back to shipboard computers. Using a crowdsourcing website, organizers of the so-called OpenCTD project are raising funds to design a CTD capable of collecting ocean data down to 200 meters at a cost of about $200.
05 Jul 2013:
Largest Offshore Wind Farm
Opened in North Sea Off British Coast
British Prime Minister David Cameron has inaugurated the world’s largest offshore wind farm
, a 630-megawatt project capable of producing enough electricity to power 500,000 homes. The $2.3 billion project — located 12 miles offshore in the North Sea, east of London — is being operated by an international consortium that includes China’s Dong Energy, German’s E.ON, and Abu Dhabi’s Masdar. The so-called London Array
project, which contains 175 turbines, began producing energy in April but was officially inaugurated yesterday by Cameron. The project’s opening solidifies the UK’s position as a global leader in offshore wind energy. The country currently produces 3 gigawatts of power from wind energy and by 2020 aims to develop 18 gigawatts, much of it from offshore wind power installations.
03 Jul 2013:
Flexible Glass Solar Cells
Could Boost Effectiveness of Solar Shingles
U.S. researchers have developed a solar shingle made of flexible glass that could emerge as an alternative to conventional roof shingles and drive down the costs of
Corning’s Willow Glass
rooftop solar energy systems. Unlike conventional solar panels, which are bulky and breakable, the new solar cell built by the National Renewable Energy Laboratory is durable enough to last for decades, according to MIT’s Technology Review
. While typical panels must be mounted on top of asphalt shingles, the glass solar shingles can be nailed directly onto a roof instead of conventional shingles. The cells are made of a pliable material called Willow Glass, which was developed by Corning, the company that also makes the so-called Gorilla glass for iPhone screens. According to researchers, the glass can also utilize cadmium telluride — which can compete on a cost basis with more widely used silicon solar cells — as the solar cell material.
02 Jul 2013:
Drought Tolerance in Plants
Boosted by New Synthetic Chemical
Scientists have identified a chemical that helps plants better tolerate drought conditions
, a discovery they say could help boost crop production as extreme weather
Click to enlarge
Cutler Lab/UC Riverside
Soybean plant, right, treated with quinabactin
conditions become more common. After testing thousands of different molecules, researchers at the University of California, Riverside found and named a chemical, quinabactin, that caused the pores, or stomata, in Arabidopsis plants to close firmly, thus preventing water loss. The action is similar to the way a naturally occurring stress hormone, known as abscisic acid (ABA), performs in drought-tolerant plant varieties. While it was previously known that ABA triggers the closing of stomata pores during dry periods, the hormone is far too expensive to apply in agricultural fields, scientists say. Writing in the Proceedings of the National Academy of Sciences
, the researchers report that the synthetic chemical mimics the effects of ABA but is much simpler chemically and cheaper to produce.