Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Inverse Method For Simultaneous Determination Of Soil Water Flux Density And Thermal Properties With A Penta-Needle Heat Pulse Probe, Changbing Yang, Masaru Sakai, Scott B. Jones Sep 2013

Inverse Method For Simultaneous Determination Of Soil Water Flux Density And Thermal Properties With A Penta-Needle Heat Pulse Probe, Changbing Yang, Masaru Sakai, Scott B. Jones

Plants, Soils, and Climate Faculty Publications

An accurate method for determination of in situ soil water flux density continues to be the most sought after and yet elusive hydrologic measurement. The penta-needle heat pulse probe (PHPP) employs a central heater needle surrounded by an orthogonal arrangement of four thermistor needles for two-component water flux density estimation. An analytical solution and inverse fitting method are presented for simultaneous estimation of thermal properties and soil water flux density using PHPP measurements. The approach yields estimates of both components of the flux in a plane normal to the axis of the PHPP needles. The method was evaluated using data …


Understanding Precision Nitrogen Stress To Optimize The Growth And Lipid Content Tradeoff In Oleaginous Green Microalgae, Curtis Adams, Valerie Godfrey, Bruce Bugbee, Brad Wahlen, Lance Seefeldt Jan 2013

Understanding Precision Nitrogen Stress To Optimize The Growth And Lipid Content Tradeoff In Oleaginous Green Microalgae, Curtis Adams, Valerie Godfrey, Bruce Bugbee, Brad Wahlen, Lance Seefeldt

Plants, Soils, and Climate Faculty Publications

Nitrogen deficiency promotes lipid formation in many microalgae, but also limits growth and lipid productivity. In spite of numerous studies, there is poor understanding of the interactions of growth and lipid content, the time course of lipid accumulation and the magnitude of nitrogen deficiency required to stimulate lipid formation. These relationships were investigated in six species of oleaginous green algae, comparing high and low levels of deficiency. Nitrogen stress typically had disproportionate effects on growth and lipid content, with profound differences among species. Optimally balancing the tradeoffs required a wide range in nitrogen supply rate among species. Some species grew …