Tech | Page 1102 | Science Codex

Study: Ground-level ozone reduces maize and soybean yields

CHAMPAIGN, Ill. -- Despite government regulations, ground-level ozone -- an odorless gas that forms as polluting nitrogen oxides drift in sunlight across the countryside -- continues to threaten crop quality and yield. In a new study, researchers quantify this loss from historical yield data for the first time. They show that over the last 30 years, ozone emissions have reduced soybean and corn yields by 5 percent and 10 percent, respectively.

The findings are reported in the Proceedings of the National Academy of Sciences.

Structure of 'concrete disease' solved

Researchers from the Paul Scherrer Institute (PSI) teamed up with colleagues from the Swiss Materials Science Lab Empa to study a degenerative sign of ageing in concrete: the so-called alkali-aggregate reaction (AAR). In the course of AAR, a material forms that takes up more space than the original concrete and thus gradually cracks the concrete from within as the decades go by.

Vector network analysis using lasers

Vector network analyzers (VNA) are among the most precise high-frequency measurement devices available today. Due to continuous development within the last decades VNAs are usable up to frequencies of 1 terahertz (1012 Hz) and complex error correction algorithms exist. However, VNAs are very expensive and require multiple frequency extenders in order to cover a wide frequency range. At the Physikalisch-Technische Bundesanstalt (PTB) a VNA has been developed which utilizes optoelectronic techniques based on femtosecond lasers.

Second harmonic generation in a high-Q crystal microresonator fabricated by femtosecond laser

High-quality (high-Q) whispering-gallery-mode (WGM) microresonators can efficiently confine light in a very small volume via total internal reflection, leading to dramatically enhanced interaction of light with matter. The WGM microresonators have benefitted various applications including nonlinear optics, cavity quantum electrodynamics, quantum optics, and biosensing, etc.

Is junk food to blame?

Soda, candy, and fast food are often painted as the prime culprits in the national discussion of obesity in the United States. While a diet of chocolate bars and cheese burgers washed down with a Coke is inadvisable from a nutritional standpoint, these foods are not likely to be a leading cause of obesity in the United States according to a new Cornell University Food and Brand Lab study conducted by the Lab co-directors David Just, PhD, and Brian Wansink, PhD.

An easy test for sickle cell disease

A team of UConn biomedical engineers, working with colleagues from Yale, MIT, and Harvard, has developed a simple, inexpensive, and quick technique for the diagnosis and monitoring of sickle cell disease that can be used in regions where advanced medical technology and training are scarce.

Trampolining water droplets

If you travel by plane in the coming months, you might witness a wintry aviation ritual in which ice and snow are cleared off the wings with a special liquid. That is necessary since tiny water droplets in the air may freeze to ice in certain weather conditions when settling on the aircraft's wings. That, in turn, can lead to turbulent airflow during take-off and hence to reduced lift -- a potentially dangerous situation. Even better than this de-icing procedure, of course, would be wings that don't allow the icy drops to stick or even actively repel them.

Births down and deaths up in Gulf dolphins

A NOAA-led team of scientists is reporting a high rate of reproductive failure in dolphins exposed to oil from the Deepwater Horizon spill. The team has monitored these bottlenose dolphins in heavily-oiled Barataria Bay for five years following the spill. Their findings, published in Proceedings of the Royal Society today, suggest that the effects of the Deepwater Horizon oil spill will be long-lasting.

New low-cost battery could help store renewable energy

Wind and solar energy projects are growing at a respectable clip. But storing electric power for days when the air is still or when the sun goes down remains a challenge, largely due to cost. Now researchers are developing a new battery that could bring the price of storage to more affordable levels. They report their new battery that uses low-cost materials -- sodium and magnesium -- in ACS' journal Chemistry of Materials.

System automatically converts 2-D video to 3-D

By exploiting the graphics-rendering software that powers sports video games, researchers at MIT and the Qatar Computing Research Institute (QCRI) have developed a system that automatically converts 2-D video of soccer games into 3-D.

The converted video can be played back over any 3-D device -- a commercial 3-D TV, Google's new Cardboard system, which turns smartphones into 3-D displays, or special-purpose displays such as Oculus Rift.

The researchers presented the new system last week at the Association for Computing Machinery's Multimedia conference.

Health campaigns that tap teen culture curtail risky adolescent behavior

Health campaigns that target teens based their social groups and subcultures, such as hip hop, preppy or alternative, can be an effective tool in dissuading adolescents from engaging in risky behaviors such as smoking and drinking, suggests a survey of the literature and a case study.

The findings will be presented at the APHA meeting in Chicago on Tuesday, Nov. 3.

Minuscule, flexible compound lenses magnify large fields of view

MADISON, Wis. -- Drawing inspiration from an insect's multi-faceted eye, University of Wisconsin-Madison engineers have created miniature lenses with vast range of vision.

Their new approach created the first-ever flexible Fresnel zone plate microlenses with a wide field of view -- a development that could allow everything from surgical scopes to security cameras to capture a broader perspective at a fraction of the size required by conventional lenses.

Wildfires may double erosion across a quarter of western US watersheds by 2050

Baltimore, MD, USA: In recent years, wildfires have burned trees and homes to the ground across many states in the western U.S., but the ground itself has not gotten away unscathed.

Wildfires, which are on the rise throughout the west as a result of prolonged drought and climate change, can alter soil properties and make it more vulnerable to erosion. A new study shows that the increase in wildfires may double soil erosion in some western U.S. states by 2050, and all that dirt ends up in streams, clogging creeks and degrading water quality.

Race matters on college campuses

Affirmative action bans not only contribute to the decline of student body diversity, but also negatively influence the success of students of color on campus, according to higher education researchers at Penn State and Columbia University.

Energy-efficient reaction drives ORNL biofuel conversion technology

OAK RIDGE, Tenn., Nov. 3, 2015 -- A new study from the Department of Energy's Oak Ridge National Laboratory explains the mechanism behind a technology that converts bio-based ethanol into hydrocarbon blend-stocks for use as fossil fuel alternatives.

Scientists have experimented for decades with a class of catalysts known as zeolites that transform alcohols such as ethanol into higher-grade hydrocarbons. As ORNL researchers were developing a new type of zeolite-based conversion technology, they found the underlying reaction unfolds in a different manner than previously thought.