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A report presents a study addressing the question of which large-eddy simulation (LES) equations are appropriate for modeling the flow of evaporating drops of a multicomponent liquid in a gas (e.g., a spray of kerosene or diesel fuel in air). The LES equations are obtained from the direct...

Modal filters in the ≈10-μm spectral range have been implemented as planar dielectric waveguides in infrared interferometric applications such as searching for Earth-like planets. When looking for a small, dim object (“Earth”) in close proximity to a large, bright object (“Sun”), the...

Today is Earth Day, the day set aside 39 years ago to inspire awareness and appreciation of the earth’s environment. There will be no shortage of commemorative activities and people pumping their chests proudly proclaiming their dedication to preserving the environment we live in. But with this country and many parts of the world...

President Obama’s recent call for the United States to reduce its stockpile of nuclear weapons has met its share of skeptics concerned about national security, given unstable political and military conditions around the world. But there’s at least one group of scientists and environmental activists adamant about...

Thermophotovoltaic cells containing multiple quantum wells have been invented as improved means of conversion of thermal to electrical energy. The semiconductor bandgaps of the quantum wells can be tailored to be narrower than those of prior thermophotovoltaic cells, thereby enabling the cells to convert energy...

A method of wavefront sensing (more precisely characterized as a method of determining the deviation of a wavefront from a nominal figure) has been invented as an improved means of assessing the performance of an optical system as affected by such imperfections as misalignments, design errors, and...

A method of detecting water-borne pathogenic bacteria is based partly on established molecular-recognition and fluorescent-labeling concepts, according to which bacteria of a species of interest are labeled with fluorescent reporter molecules and the bacteria can then be detected by...

Measurement of Raman and native fluorescence emission using ultraviolet (UV) sources (<400 nm) on targeted materials is suitable for both sensitive detection and accurate identification of explosive materials. When the UV emission data are analyzed using a combination of Principal...

In-situ sensors near volcanoes would be alerted by the Earth Observing-1 (EO-1) craft to take more frequent data readings. This project involves developing a sulfur-dioxide-sensing volcano monitor that will be able to transmit its readings through an Iridium modem. The monitor, when...

In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/ electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a...

Thermophotovoltaic cells containing multiple quantum wells have been invented as improved means of conversion of thermal to electrical energy. The semiconductor bandgaps of the quantum wells can be tailored to be narrower than those of prior thermophotovoltaic cells, thereby enabling the cells to convert energy...

A document discusses the adaptation of a patented biomass-digesting process, denoted sequential batch anaerobic composting (SEBAC), to recycling of wastes aboard a spacecraft. In SEBAC, high-solids-content biomass wastes are converted into methane, carbon dioxide, and compost.

For many of us on Earth, the Internet is a vital part of our everyday lives. Rapid advances in developing high-bandwidth networks make it possible to communicate with family, friends, and business associates worldwide and rapidly search for and retrieve information, 24 hours a day, 365 days a year. But in outer...

An instrument that functions mainly as a particle-image velocimeter provides data on the sizes and velocities of flying opaque particles. The instrument is being developed as a means of characterizing fluxes of wind-borne dust particles in the Martian atmosphere. The instrument could also...